mRNA encoding nerve growth factor (NGF), and composition and use thereof

Abstract

Provided are an mRNA encoding a nerve growth factor (NGF), and a composition and use thereof. ORF sequences having a high protein expression level are obtained by means of codon optimization and screening, and multiple groups of mRNAs having a high NGF protein expression level are obtained by means of combined screening of 5'UTR and 3'UTR; furthermore, after recombinant fusion of the ORF sequences, the expression efficiency and stability of the mRNA are significantly improved; and the mRNA also has a good protein expression effect in animal bodies. Thus, the provided mRNA can be used to ameliorate NGF deficiency in animal bodies, thereby preventing and / or treating neuronal disorders caused by NGF deficiency, in particular neurotrophic keratitis.

Description

mRNA encoding nerve growth factor (NGF), its composition and application Technical field The present invention relates to the field of biopharmaceutical technology, and more specifically, to mRNA encoding nerve growth factor (NGF), its composition and application. Background technique The cornea is rich in trigeminal nerves and can express a variety of epithelial trophic nerve mediators, such as substance P, calcitonin gene-related peptide, etc., which promote DNA synthesis, stimulate corneal epithelial cell proliferation, adhesion and migration. When the nerves are damaged, the secretion of these substances decreases, resulting in impaired physiological turnover of the corneal epithelium and tear function. Neurotrophic keratitis (NK) is a corneal degenerative disease caused by trigeminal nerve injury, characterized by decreased or absent corneal sensation, dry eye, corneal epithelial defect and corneal ulcer, and ultimately leading to corneal stromal melting and perforation. Nerve growth factor (NGF) promotes the development, differentiation, growth and maturation of central and peripheral neurons, maintains the normal function of the nervous system, and accelerates the repair after nervous system injury. NGF can also promote the repair of corneal epithelial cells. Cenegermin eye drops rhNGF has obtained orphan drug designation from the FDA and is the only drug approved by the FDA for the treatment of neurotrophic keratitis. It was approved for marketing in China on August 12, 2020 as a drug in short supply in the country. The clinical trial results show that rhNGF can effectively restore corneal integrity, corneal sensitivity and transparency. There is no obvious toxicity with local administration. If local administration is excessive, the eyes can be rinsed with warm water. Generally, it has negligible systemic absorption and is not distributed throughout the body, without the risk of systemic toxicity. However, this drug has withdrawn from the Chinese market, so there is a lack of such drugs in the current market. In recent years, with the progress of science and technology, mRNA drugs have become a major research focus. They have many advantages, such as no risk of genomic integration, relatively low immunogenicity, can be directly and quickly translated into proteins, high safety, natural metabolites, and low toxic and side effects, etc. At the same time, the production of mRNA is convenient and fast, the production cost is relatively low, and the administration frequency can be reduced. Therefore, compared with protein drugs, the cost of mRNA drugs is significantly reduced when producing the same therapeutic effect. However, there is currently no relevant report on mRNA drugs that regulate the expression of nerve growth factor (NGF). Summary of the invention The purpose of the present invention is to provide mRNA encoding nerve growth factor (NGF). Another purpose of the present invention is to provide a composition containing mRNA encoding nerve growth factor (NGF). Another object of the present invention is to provide the use of mRNA encoding nerve growth factor (NGF). The above object of the present invention is achieved by the following solutions: An mRNA encoding nerve growth factor, the mRNA comprising a coding region; the coding region comprising one or more ORFs; the ORF being selected from SEQ ID NO: 20-27 or a sequence having at least 98% similarity to one of SEQ ID NO: 20-27. In the present application, an ORF refers to a nucleic acid sequence that can encode a sequence such as SEQ ID NO: 2001 or 2002; or a nucleic acid sequence encoding SEQ ID NO: 2001 or 2002 with an HSA, ABD or IgG4-Fc fragment at the C-terminus, such as any one of SEQ ID NO: 1041-1043, SEQ ID NO: 1091-1093, or can also be any nucleic acid sequence formed by the combination of any one of SEQ ID NO: 20-27 + SEQ ID NO: 28 + SEQ ID NO: 32. In an embodiment, the ORF is one of the following cases: (1) The ORF is SEQ ID NO: 20; (2) The ORF is SEQ ID NO: 21; (3) The ORF is SEQ ID NO: 22; (4) The ORF is SEQ ID NO: 23; (5) The ORF is SEQ ID NO: 24; (6) The ORF is SEQ ID NO: 25; (7) The ORF is SEQ ID NO: 26; (8) The ORF is SEQ ID NO: 27. In one embodiment, the ORF is selected from SEQ ID NO: 1041-1043, SEQ ID NO: 1091-1093, SEQ ID NO: 1131-1133 or a sequence having at least 98% similarity to one of SEQ ID NO: 1041-1043, SEQ ID NO: 1091-1093, SEQ ID NO: 1131-1133. In one embodiment, the ORF is one of the following cases: (1) The ORF is SEQ ID NO: 1041; (2) The ORF is SEQ ID NO: 1042; (3) The ORF is SEQ ID NO: 1043; (4) The ORF is SEQ ID NO: 1091; (5) The ORF is SEQ ID NO: 1092; (6) The ORF is SEQ ID NO: 1093; (7) The ORF is SEQ ID NO: 1131; (8) The ORF is SEQ ID NO: 1132; (9) The ORF is SEQ ID NO: 1133. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs can be the same or different; any one of the sequences of SEQ ID NO: 28, 29 or 33 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs can be the same or different; SEQ ID NO: 28 or 29 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs can be the same or different; SEQ ID NO: 28 or 33 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs can be the same or different; SEQ ID NO: 29 or 33 serves as a spacer sequence between each ORF. In one embodiment, the spacer sequence can be the Linker of SEQ ID NO: 28, or P2A, or IRES. In one embodiment, when the coding region contains at least three ORFs, the spacer sequences can be the same or different. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1011 - 1013, 1021 - 1023, 1031 - 1033, 1051 - 1053, 1061 - 1063, 1071 - 1073, 1081 - 1083, 1101 - 1103, 1111 - 1113, 1121 - 1123, 1131 - 1133. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1011 - 1013, 1021 - 1023 or 1031 - 1033. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1021 - 1023. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1031 - 1033. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1051 - 1053, 1061 - 1063, 1071 - 1073 or 1081 - 1083. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1061 - 1063. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1071 - 1073. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1081 - 1083. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1101 - 1103. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1111 - 1113. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1121 - 1123. In one embodiment, the mRNA further includes a 5'UTR, and its sequence is selected from any one of SEQ ID NOs: 1 - 15. In an embodiment, the mRNA further includes a 5'UTR, and its sequence is one of the following cases: (1) The 5'UTR sequence is SEQ ID NO: 1; (2) The 5'UTR sequence is SEQ ID NO: 2; (3) The 5'UTR sequence is SEQ ID NO: 3; (4) The 5'UTR sequence is SEQ ID NO: 4; (5) The 5'UTR sequence is SEQ ID NO: 5; (6) The 5'UTR sequence is SEQ ID NO: 6; (7) The 5'UTR sequence is SEQ ID NO: 7; (8) The 5'UTR sequence is SEQ ID NO: 8; (9) The 5'UTR sequence is SEQ ID NO: 9; (10) The 5'UTR sequence is SEQ ID NO: 10; (11) The 5'UTR sequence is SEQ ID NO: 11; (12) The 5'UTR sequence is SEQ ID NO: 12; (13) The 5'UTR sequence is SEQ ID NO: 13; (14) The 5'UTR sequence is SEQ ID NO: 14; (15) The 5'UTR sequence is SEQ ID NO: 15. In one embodiment, the mRNA further includes a 5'UTR, and its sequence is SEQ ID NO: 3. In one embodiment, the mRNA further includes a 3'UTR, and its sequence is selected from any one of SEQ ID NOs: 16 - 19. In an embodiment, the mRNA further includes a 3' UTR, and the sequence thereof is one of the following cases: (1) The 3' UTR sequence is SEQ ID NO: 16; (2) The 3' UTR sequence is SEQ ID NO: 17; (3) The 3' UTR sequence is SEQ ID NO: 18; (4) The 3' UTR sequence is SEQ ID NO: 19. In one embodiment, the mRNA further includes a 3' UTR, and the sequence thereof is SEQ ID NO: 16. In one embodiment, the mRNA further includes poly A, which contains at least 70 adenosines. In one embodiment, poly A contains 70 - 140 adenosines, or 70 - 120 adenosines, or 80 - 120 adenosines, or 90 - 120 adenosines, or 100 - 140 adenosines, or 100 - 120 adenosines. In one embodiment, the mRNA further includes a 5' cap structure. In one embodiment, the 5' cap structure is selected from Cap0, Cap1, Cap2 or the structure shown in Formula I: Wherein, R1 is H, C 1-4 alkyl, C 1-4 haloalkyl, phenyl, C 1-4 alkyl-substituted phenyl, halophenyl, benzyl, C 1-4 alkyl-substituted benzyl or halobenzyl; R2 is OH, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkyl, C 1-4 alkoxy-substituted C 1-4 alkyl, C 1-4 alkylamino-substituted C 1-4 alkyl, C 1-4 amido-substituted C 1-4 alkyl, benzyloxy, halobenzyloxy, benzyloxy-substituted C 1-4 alkyl or halobenzyloxy-substituted C 1- 4-alkyl; R3 and R4 are each independently H, C 1-4 alkyl or C 1-4 haloalkyl; R5 is H, C 1-4 alkoxy, F, Cl, I or N3; R6 is H, C 1-4 alkyl, C 1-4 alkenyl, C 1-4 alkynyl, phenyl, C 1-4alkyl-substituted phenyl, halogenated phenyl, benzyl, C 1-4 alkyl-substituted benzyl or halogenated benzyl; B1 and B2 are each independently a base G, A, U or C, and substituted bases include but are not limited to 6-MeA, 5-MeU or 5-MeC. In one embodiment, the mRNA comprises at least one chemically modified nucleoside. In one embodiment, the chemically modified nucleoside is selected from pseudouridine, N1-methyl-pseudouridine, 1-ethylpseudouridine, 2-thiouridine, 4′-thiouridine, 5-methyluridine or 5-methoxyuridine, or any combination thereof. In one embodiment, the chemically modified nucleoside is selected from pseudouridine. In one embodiment, the chemically modified nucleoside is selected from N1-methyl-pseudouridine. In one embodiment, the chemically modified nucleoside is selected from pseudouridine and / or N1-methyl-pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 1-ethylpseudouridine. In one embodiment, the chemically modified nucleoside is selected from 1-ethylpseudouridine and / or N1-methyl-pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 1-ethylpseudouridine and / or pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 4′-thiouridine. In one embodiment, the chemically modified nucleoside is selected from 4′-thiouridine and / or N1-methyl-pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 4′-thiouridine and / or pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 5-methyluridine. In one embodiment, the chemically modified nucleoside is selected from 5-methyluridine and / or N1-methyl-pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 5-methyluridine and / or pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 5-methoxyuridine. In one embodiment, the chemically modified nucleoside is selected from 5-methoxyuridine and / or N1-methyl-pseudouridine. In one embodiment, the chemically modified nucleoside is selected from 5-methoxyuridine and / or pseudouridine. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 10-100%, or 20-100%, or 30-100%, or 40-100%, or 50-100%, or 60-100%, or 70-100%, or 80-100%, or 90-100%, or 50-98%, or 50-95%, or 60-95%, or 70-95%, or 80-95%, or 90-95%, or 70-90%, or 80-90%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 10-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 20-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 30-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 40-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 50-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 60-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 70-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 80-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 90-100%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 50-98%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 50-95%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 60-95%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 70-95%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 80-95%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 90-95%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 70-90%. In one embodiment, the proportion of chemically modified nucleosides in the mRNA is 80-90%. In one embodiment, the amino acid sequence encoded by the mRNA comprises SEQ ID NO: 2001 or SEQ ID NO. 2002. In one embodiment, the amino acid sequence encoded by the mRNA is any one of SEQ ID NO: 2001-2013. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2001. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2002. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2003. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2004. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2005. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2006. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2007. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2008. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2009. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2010. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2011. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2012. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2013. In one embodiment, the amino acid sequence encoded by the mRNA is SEQ ID NO: 2014. In one embodiment, the mRNA comprises: (ii) a 5'UTR; the 5'UTR is selected from any one of SEQ ID NO: 1-15; (iii) Coding region; the coding region contains one or more ORFs; the ORFs are selected from SEQ ID NO: 20 - 27 or a sequence with at least 98% similarity to one of SEQ ID NO: 20 - 27; (iv) 3’UTR; the 3’UTR is selected from any one of SEQ ID NO: 16 - 19; (v) poly A; the poly A contains at least 70 adenosines. In an embodiment, the ORF is one of the following cases: (1) The ORF is SEQ ID NO: 20; (2) The ORF is SEQ ID NO: 21; (3) The ORF is SEQ ID NO: 22; (4) The ORF is SEQ ID NO: 23; (5) The ORF is SEQ ID NO: 24; (6) The ORF is SEQ ID NO: 25; (7) The ORF is SEQ ID NO: 26; (8) The ORF is SEQ ID NO: 27. In an embodiment, the 5'UTR sequence is one of the following cases: (1) The 5'UTR sequence is SEQ ID NO: 1; (2) The 5'UTR sequence is SEQ ID NO: 2; (3) The 5'UTR sequence is SEQ ID NO: 3; (4) The 5'UTR sequence is SEQ ID NO: 4; (5) The 5'UTR sequence is SEQ ID NO: 5; (6) The 5'UTR sequence is SEQ ID NO: 6; (7) The 5'UTR sequence is SEQ ID NO: 7; (8) The 5'UTR sequence is SEQ ID NO: 8; (9) The 5'UTR sequence is SEQ ID NO: 9; (10) The 5'UTR sequence is SEQ ID NO: 10; (11) The 5'UTR sequence is SEQ ID NO: 11; (12) The 5'UTR sequence is SEQ ID NO: 12; (13) The 5'UTR sequence is SEQ ID NO: 13; (14) The 5'UTR sequence is SEQ ID NO: 14; (15) The 5'UTR sequence is SEQ ID NO: 15. In one of the embodiments, the mRNA further includes a 5'UTR, and its sequence is SEQ ID NO: 3. In an embodiment, the sequence of the 3’UTR is one of the following cases: (1) The 3’UTR sequence is SEQ ID NO: 16; (2) The 3’UTR sequence is SEQ ID NO: 17; (3) The 3’UTR sequence is SEQ ID NO: 18; (4) The 3’UTR sequence is SEQ ID NO: 19. In one embodiment, the mRNA further includes a 3’UTR, the sequence of which is SEQ ID NO: 16. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs may be the same or different; any one of the sequences of SEQ ID NO: 28, 29 or 33 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs may be the same or different; SEQ ID NO: 28 or 29 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs may be the same or different; SEQ ID NO: 28 or 33 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least two ORFs, the sequences of the ORFs may be the same or different; SEQ ID NO: 29 or 33 serves as a spacer sequence between each ORF. In one embodiment, when the coding region contains at least three ORFs, the spacer sequences may be the same or different; When the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1011-1013, 1021-1023, 1031-1033, 1051-1053, 1061-1063, 1071-1073, 1081-1083, 1101-1103, 1111-1113, 1121-1123. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1011-1013, 1021-1023 or 1031-1033. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1021-1023. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1031-1033. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1051-1053, 1061-1063, 1071-1073 or 1081-1083. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NO: 1061-1063. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1071-1073. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1081-1083. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1101-1103. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1111-1113. In one embodiment, when the coding region contains at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1121-1123. In one embodiment, the mRNA further comprises (i) a 5' cap structure selected from Cap0, Cap1, Cap2 or a structure shown in Formula I: wherein, R1 is H, C 1-4 alkyl, C 1-4 haloalkyl, phenyl, C 1-4 alkyl-substituted phenyl, halophenyl, benzyl, C 1-4 alkyl-substituted benzyl or halobenzyl; R2 is OH, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkyl, C 1-4 alkoxy-substituted C 1-4 alkyl, C 1-4 alkylamino-substituted C 1-4 alkyl, C 1-4 amido-substituted C 1-4 alkyl, benzyloxy, halobenzyloxy, benzyloxy-substituted C 1-4 alkyl or halobenzyloxy-substituted C 1- 4-alkyl; R3 and R4 are each independently H, C 1-4 alkyl or C 1-4 haloalkyl; R5 is H, C 1-4 alkoxy, F, Cl, I or N3; R6 is H, C 1-4 alkyl, C 1-4 alkenyl, C 1-4 alkynyl, phenyl, C 1-4 alkyl-substituted phenyl, halophenyl, benzyl, C 1-4 alkyl-substituted benzyl or halobenzyl; B1 and B2 are each independently a base G, A, U, or C, and substituted bases include, but are not limited to, 6-MeA, 5-MeU, or 5-MeC. In one embodiment, R6 is H, C 1-4 alkyl, C 1-4 alkenyl, C 1-4 alkynyl, phenyl, halophenyl, benzyl, or halobenzyl. In one embodiment, R6 is H, C 1-4 alkyl, phenyl, halophenyl, benzyl, or halobenzyl. In one embodiment, R6 is H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, phenyl, benzyl, 3-fluorophenyl, 4-fluorophenyl, 3,5-difluorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3,5-dichlorophenyl, 3-fluorobenzyl, 4-fluorobenzyl, 3,5-difluorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, or 3,5-dichlorobenzyl. In one embodiment, R6 is H, methyl, ethyl, propyl, isopropyl, phenyl, benzyl, 3-fluorophenyl, 4-fluorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorobenzyl, 4-fluorobenzyl, 3-chlorobenzyl, or 4-chlorobenzyl. In one embodiment, R6 is H, methyl, ethyl, isopropyl, phenyl, benzyl, 4-fluorophenyl, 4-chlorophenyl, 4-fluorobenzyl, or 4-chlorobenzyl. In one embodiment, R6 is H, methyl, ethyl, isopropyl, phenyl, benzyl, 4-fluorophenyl, or 4-fluorobenzyl. In one embodiment, R6 is H or methyl. In one embodiment, R6 is phenyl or 4-fluorophenyl. In one embodiment, R6 is benzyl or 4-fluorobenzyl. In one embodiment, R5 is H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, F, Cl, I, or N3. In one embodiment, R5 is H, methyl, ethyl, propyl, isopropyl, tert-butyl, F, or N3. In one embodiment, R5 is H, methyl, ethyl, isopropyl, F, or N3. In one embodiment, R5 is H, methyl, ethyl, F, or N3. In one embodiment, R5 is H or F. In one embodiment, R5 is H or methyl. In one embodiment, R5 is F or N3. In one embodiment, R3 and R4 are each independently H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, trifluoromethyl, trifluoroethyl, trifluoropropyl or trifluoroisopropyl. In one embodiment, R3 and R4 are each independently H, methyl, ethyl, isopropyl, tert-butyl, trifluoromethyl, trifluoroethyl or trifluoroisopropyl. In one embodiment, R3 and R4 are each independently H, methyl, ethyl, isopropyl, trifluoromethyl or trifluoroethyl. In one embodiment, R3 and R4 are each independently H, methyl, ethyl or trifluoromethyl. In one embodiment, R3 and R4 are each independently H, methyl or trifluoromethyl. In one embodiment, R2 is OH, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkyl, C 1-4 alkoxy-substituted C 1-4 alkyl, C 1-4 alkylamino-substituted C 1-4 alkyl, C 1-4 amido-substituted C 1-4 alkyl, benzyloxy or benzyloxy-substituted C 1-4 alkyl. In one embodiment, R2 is OH, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkyl, C 1-3 alkoxy-substituted C 1-3 alkyl, C 1-3 alkylamino-substituted C 1-3 alkyl, C 1-3 amido-substituted C 1-3 alkyl, benzyloxy or benzyloxy-substituted C 1-3 alkyl. In one embodiment, R2 is OH, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkyl, C 1-3 alkoxy-substituted C 1-3 alkyl, C 1-3 alkylamino-substituted C 1-3 alkyl or C 1-3 amido-substituted C 1-3 alkyl. In one embodiment, R2 is OH, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkyl or C1-3 Alkoxy-substituted C 1-3 alkyl group. In one embodiment, R2 is OH, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, trifluoromethyl, trifluoroethyl, trifluoropropyl, trifluoroisopropyl, methoxymethyl, methoxyethyl, methoxypropyl, methoxyisopropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxyisopropyl, propoxymethyl, propoxyethyl, isopropoxymethyl or isopropoxyethyl. In one embodiment, R2 is OH, methyl, ethyl, propyl, isopropyl, tert-butyl, methoxy, ethoxy, propoxy, isopropoxy, tert-butoxy, trifluoromethyl, trifluoroethyl, trifluoropropyl, trifluoroisopropyl, methoxymethyl, methoxyethyl, methoxyisopropyl, ethoxymethyl, ethoxyethyl, ethoxyisopropyl, propoxymethyl, propoxyethyl, isopropoxymethyl or isopropoxyethyl. In one embodiment, R2 is OH, methyl, ethyl, methoxy, ethoxy, isopropoxy, tert-butoxy, trifluoromethyl, trifluoroethyl, trifluoropropyl, trifluoroisopropyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, propoxymethyl, propoxyethyl, isopropoxymethyl or isopropoxyethyl. In one embodiment, R2 is OH, methyl, ethyl, methoxy, ethoxy, trifluoromethyl, trifluoroethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, propoxymethyl, propoxyethyl, isopropoxymethyl or isopropoxyethyl. In one embodiment, R2 is OH, methoxy, ethoxy, trifluoromethyl, methoxymethyl or ethoxymethyl. In one embodiment, R2 is OH, methoxy or methoxymethyl. In one embodiment, R2 is -CH2NHCH3, -CH2NHC2H5, -CH2NHC3H7, -CH2NHC4H9, -C2H4NHCH3, -C2H4NHC2H5, -C2H4NHC3H7, -C2H4NHC4H9, -C3H6NHCH3, -C3H6NHC2H5, -C3H6NHC3H7, -C3H6NHC4H9, -CH2NHCOCH3, -CH2NHCOC2H5, -CH2NHCOC3H7, -C2H4NHCOC2H5 or -C2H4NHCOC3H7. In one embodiment, R2 is -CH2NHCH3, -CH2NHC2H5, -CH2NHC3H7, -C2H4NHCH3, -C2H4NHC2H5, -C2H4NHC3H7, -C3H6NHCH3, -C3H6NHC2H5, -C3H6NHC3H7, -CH2NHCOCH3, -CH2NHCOC2H5, -CH2NHCOC3H7 or -C2H4NHCOC2H5. In one embodiment, R2 is -CH2NHCH3, -CH2NHC2H5, -CH2NHC3H7, -C2H4NHCH3, -C2H4NHC2H5, -C3H6NHCH3, -C3H6NHC2H5, -CH2NHCOCH3, -CH2NHCOC2H5 or -C2H4NHCOC2H5. In one embodiment, R2 is -CH2NHCH3, -CH2NHC2H5, -CH2NHC3H7, -C2H4NHCH3, -C2H4NHC2H5, -CH2NHCOCH3 or -CH2NHCOC2H5. In one embodiment, R2 is -CH2NHCH3, -CH2NHC2H5, -CH2NHC3H7, -CH2NHCOCH3 or -CH2NHCOC2H5. In one embodiment, R2 is CH2NHCOCH3 or -CH2NHCOC2H5. In one embodiment, R1 is H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, trifluoromethyl, trifluoroethyl, trifluoropropyl, trifluoroisopropyl, phenyl, 2-methyl-phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2,6-dimethyl-phenyl, 3,5-dimethyl-phenyl, 2-ethyl-phenyl, 3-ethyl-phenyl, 4-ethyl-phenyl, 2,6-diethyl-phenyl, 3,5-diethyl-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2,6-chloro-phenyl, 3,5-chloro-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, 2,6-fluoro-phenyl, 3,5-fluoro-phenyl, benzyl, 2-methyl-benzyl, 3-methyl-benzyl, 4-methyl-benzyl, 2,6-dimethyl-benzyl, 3,5-dimethyl-benzyl, 2-ethyl-benzyl, 3-ethyl-benzyl, 4-ethyl-benzyl, 2,6-diethyl-benzyl, 3,5-diethyl-benzyl, 2-chloro-benzyl, 3-chloro-benzyl, 4-chloro-benzyl, 2,6-chloro-benzyl, 3,5-chloro-benzyl, 2-fluoro-benzyl, 3-fluoro-benzyl, 4-fluoro-benzyl, 2,6-fluoro-benzyl or 3,5-fluoro-benzyl. In one embodiment, R1 is H, methyl, ethyl, propyl, isopropyl, tert-butyl, trifluoromethyl, trifluoroethyl, trifluoropropyl, trifluoroisopropyl, phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 3,5-dimethyl-phenyl, 3-ethyl-phenyl, 4-ethyl-phenyl, 3,5-diethyl-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 3,5-chloro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, 3,5-fluoro-phenyl, benzyl, 3-methyl-benzyl, 4-methyl-benzyl, 3,5-dimethyl-benzyl, 3-ethyl-benzyl, 4-ethyl-benzyl, 3,5-diethyl-benzyl, 3-chloro-benzyl, 4-chloro-benzyl, 3,5-chloro-benzyl, 3-fluoro-benzyl, 4-fluoro-benzyl or 3,5-fluoro-benzyl. In one embodiment, R1 is H, methyl, ethyl, isopropyl, tert-butyl, trifluoromethyl, trifluoroethyl, trifluoroisopropyl, phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 3,5-dimethyl-phenyl, 4-ethyl-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, benzyl, 3-methyl-benzyl, 4-methyl-benzyl, 3-ethyl-benzyl, 4-ethyl-benzyl, 3-chloro-benzyl, 4-chloro-benzyl, 3-fluoro-benzyl or 4-fluoro-benzyl. In one embodiment, R1 is H, methyl, ethyl, isopropyl, tert-butyl, trifluoromethyl, trifluoroethyl, trifluoroisopropyl, phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-chloro-phenyl, 4-fluoro-phenyl, benzyl, 4-methyl-benzyl, 4-ethyl-benzyl, 4-chloro-benzyl or 4-fluoro-benzyl. In one embodiment, R1 is H, methyl, ethyl, isopropyl, trifluoromethyl, trifluoroethyl, benzyl, 4-methyl-benzyl, 4-ethyl-benzyl, 4-chloro-benzyl or 4-fluoro-benzyl. In one embodiment, R1 is H, methyl, ethyl, isopropyl, trifluoromethyl, trifluoroethyl, benzyl, 4-methyl-benzyl or 4-fluoro-benzyl. In some embodiments, the 5'-cap structure can be, but is not limited to, the following compounds: The present invention also protects a composition comprising the aforementioned mRNA encoding nerve growth factor and a delivery agent. In one embodiment, the delivery agent comprises lipid nanoparticles; the lipid nanoparticles comprise: cationic lipids, phospholipids, cholesterol and PEG lipids. In one embodiment, the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticle is 30-60:0-30:18.5-48.5:0-10. In one embodiment, the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticle is 35-55:0-25:20-45:0.5-8. In one embodiment, the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticle is 40-52:5-20:25-40:0.5-5. In one embodiment, the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticle is 45-52:8-15:30-40:1-5. In one embodiment, the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticle is 50:10:38.5:1.5. In one embodiment, the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticle is 48.5:11.1:38.9:1.5. In one embodiment, the cationic lipid is represented by Formula II: Wherein, n0 is an integer from 0 to 4; n1 is an integer from 2 to 7; n2 is an integer from 4 to 10; n3 is an integer from 2 to 8; n4 is an integer from 2 to 8; n5 is an integer from 2 to 8. In one embodiment, n0 is 0, 1, 2, 3 or 4; preferably, n0 is 1, 2 or 3; more preferably, n0 is 1 or 2. In one embodiment, n1 is 2, 3, 4, 5, 6 or 7; preferably, n1 is 2, 3, 4 or 5; more preferably, n1 is 2, 3 or 4. In one embodiment, n2 is 4, 5, 6, 7, 8, 9 or 10; preferably, n2 is 6, 7, 8, 9 or 10; more preferably, n2 is 8, 9 or 10. In one embodiment, n3 is 2, 3, 4, 5, 6, 7 or 8; preferably, n3 is 3, 4, 5 or 6; more preferably, n3 is 4, 5 or 6. In one embodiment, n4 is 2, 3, 4, 5, 6, 7 or 8; preferably, n4 is 3, 4, 5 or 6; more preferably, n4 is 4, 5 or 6. In one embodiment, n5 is 2, 3, 4, 5, 6, 7 or 8; preferably, n5 is 3, 4, 5 or 6; more preferably, n5 is 4, 5 or 6. In one embodiment, the cationic lipid is one or more combinations of SM102, MC3, DOTAP, ALC-0315, H1, H2, H3, H4, H5, and H6. In one embodiment, the cationic lipid is one of the following: (1) The cationic lipid is SM102; (2) The cationic lipid is MC3; (3) The cationic lipid is DOTAP; (4) The cationic lipid is ALC-0315; (5) The cationic lipid is H1; (6) The cationic lipid is H2; (7) The cationic lipid is H3; (8) The cationic lipid is H4; (9) The cationic lipid is H5; (10) The cationic lipid is H6. Their structures are shown below: In one embodiment, the phospholipid is DSPC or DOPE; the molecular weight of the PEG lipid is PEG, a PEG-modified compound or a mixture thereof with a molecular weight of 1000 Da to 20 kDa. In one embodiment, in the composition, the mRNA is encapsulated in lipid nanoparticles. In one embodiment, the composition further comprises a pharmaceutically acceptable excipient. The present invention also protects the use of the aforementioned mRNA encoding nerve growth factor or the aforementioned composition in the preparation of a drug for preventing and / or treating diseases including but not limited to corneal diseases, optic nerve diseases, conjunctival diseases, limbal stem cell deficiency, and dry eye. In one embodiment, the corneal disease is selected from keratoconus, phototoxic corneal disease, persistent corneal epithelial defect, corneal ulcer, corneal dystrophy and degeneration, keratoconjunctivitis sicca or neurotrophic keratitis. In one embodiment, the corneal disease is selected from corneal dystrophy and degeneration, keratoconjunctivitis sicca or neurotrophic keratitis. In one embodiment, the optic nerve disease is selected from glaucoma and ischemic optic neuropathy, degenerative, traumatic, Leber hereditary optic neuropathy, and congenital optic atrophy. In one embodiment, the corneal disease is neurotrophic keratitis. In one embodiment, the dry eye is selected from aqueous tear-deficient dry eye, lipid abnormal dry eye, mucin abnormal dry eye, tear film instability dry eye, and mixed dry eye. In one embodiment, dry eye diseases are selected from aqueous tear-deficient dry eye, lipid abnormal dry eye, and mixed dry eye. The present invention also protects the use of the aforementioned mRNA encoding nerve growth factor or the aforementioned composition in the preparation of drugs for preventing and / or treating peripheral neuropathy and idiopathic facial paralysis. In one embodiment, peripheral neuropathy includes but is not limited to AIDS-related sensory neuropathy, diabetic polyneuropathy, toxic peripheral neuropathy, and traumatic peripheral nerve injury. In one embodiment, the drug is a topically used drug. In one embodiment, the drug is an injection, a topical preparation, a nasal spray, or an eye drop. The present invention also protects a method for preventing and / or treating corneal lesions, optic nerve lesions, conjunctival lesions, limbal stem cell deficiency, or dry eye diseases, including administering a therapeutically effective amount of the aforementioned mRNA encoding nerve growth factor or the aforementioned composition to a subject in need. In one embodiment, it further includes administering other medicaments to the subject. In one embodiment, corneal lesions are selected from keratoconus, phototoxic corneal lesions, persistent corneal epithelial defects, corneal ulcers, corneal dystrophies and degenerations, keratoconjunctivitis sicca, or neurotrophic keratitis. In one embodiment, optic nerve lesions are selected from glaucoma, as well as ischemic optic neuropathy, degenerative, traumatic, Leber hereditary optic neuropathy, and congenital optic atrophy. Compared with the prior art, the present invention has the following beneficial effects: Through codon optimization and screening, the present invention obtains an ORF sequence with high protein expression, and through the combination screening of 5'UTR and 3'UTR, multiple groups of mRNAs with good NGF protein expression are obtained; further, after recombinant fusion of the ORF sequence, the expression efficiency and stability of the mRNA are significantly improved; and the mRNA also has a good protein expression effect in animals; indicating that the mRNA provided by the present invention can be used to improve NGF deficiency in animals, thereby preventing and / or treating neuronal diseases caused by NGF deficiency, especially neurotrophic keratitis. Description of the Drawings Figure 1 shows the effect of the protein expressed by the mRNA in Example 2 on PC12 cells. Figure 2 shows the effect of the protein expressed by the mRNA in Example 3 on HCEC cells. Figure 3 shows the weight recording results of each group of mice in Example 5. Figure 4 shows the corneal sensation recovery effect of each group of mice in Example 5. FIG. 5 is the test results of the IOD values ​​of the corneal staining areas of each group of mice in Example 5. FIG. 6 is the test results of the corneal staining area of ​​each group of mice in Example 5. FIG. 7 is the test results of corneal neuropathy grading of each group of mice in Example 5. FIG. 8 shows the effect of mRNA protein expression on PC12 cells in Example 2. FIG. 9 shows the effect of mRNA protein expression on HCEC cells in Example 3. DETAILED DESCRIPTION the term As used herein and unless otherwise specified, the term "alkyl" refers to a saturated group consisting solely of carbon and hydrogen atoms.

[0089] A straight or branched hydrocarbon chain group. In one embodiment, an alkyl group has, for example, 1 to 24 carbon atoms (C1-C1 alkyl), 4 to 20 carbon atoms (C1-C1 alkyl), 6 to 16 carbon atoms (C1-C1 alkyl), 6 to 9 carbon atoms (C1-C1 alkyl), 1 to 15 carbon atoms (C1-C1 alkyl), 1 to 12 carbon atoms (C1-C1 alkyl), 1 to 8 carbon atoms (C1-C1 alkyl), or 1 to 6 carbon atoms (C1-C1 alkyl), and is connected to the rest of the molecule by a single bond. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, n-pentyl, 1,1-dimethylethyl (tert-butyl), 3-methylhexyl, 2-methylhexyl, etc. Unless otherwise indicated, an alkyl group is optionally substituted. The term "lipid nanoparticle" or "LNP" refers to a particle with at least one nanometer (nm) size (e.g., 1 to 1000 nm) containing one or more types of lipid molecules. The LNP provided herein may further contain at least one non-lipid payload molecule (e.g., one or more nucleic acid molecules). In some embodiments, the LNP comprises a non-lipid payload molecule partially or completely encapsulated in a lipid shell. Specifically, in some embodiments, wherein the payload is a negatively charged molecule (e.g., mRNA encoding a therapeutic protein), and the lipid component of the LNP comprises at least one cationic lipid. Without being bound by theory, it is expected that cationic lipids can interact with negatively charged payload molecules and promote the incorporation and / or encapsulation of payloads into the LNP during LNF formation. Other lipids that may form a part of the LNP as provided herein include, but are not limited to, neutral lipids and charged lipids, such as steroids, polymer-bound lipids, and various zwitterionic lipids. The term "cationic lipid" refers to a lipid that is positively charged at any pH or hydrogen ion activity of its environment, or that is capable of becoming positively charged in response to the pH or hydrogen ion activity of its environment (e.g., the environment in which it is intended to be used). Thus, the term "cationic" encompasses "permanent cations" and "cationizable". In certain embodiments, the positive charge in the cationic lipid is caused by the presence of a quaternary nitrogen atom. In certain embodiments, the cationic lipid comprises an amphoteric lipid that is positively charged in its intended use environment (e.g., at physiological pH). As used herein and unless otherwise indicated, the term "pharmaceutically acceptable salt" includes both acid addition salts and base addition salts. As used herein and unless otherwise indicated, the term "pharmaceutically acceptable carrier, diluent or excipient" includes, but is not limited to, any adjuvant, carrier, excipient, glidant, sweetening agent, diluent, preservative, dye / colorant, flavor enhancer, surfactant, wetting agent, dispersing agent, suspending agent, stabilizing agent, isotonic agent, solvent or emulsifying agent that is approved for use in humans or livestock. The term "composition" is intended to encompass a product containing a specified amount of a specified ingredient (e.g., an mRNA molecule provided herein) optionally selected. In certain embodiments, the mRNA is a monocistronic mRNA containing only one ORF. In certain embodiments, the monocistronic mRNA encodes a peptide or protein containing at least one epitope of a selected antigen (e.g., a pathogenic antigen or a tumor-associated antigen). In other embodiments, the mRNA is a polycistronic mRNA containing two or more ORFs. In certain embodiments, the polycistronic mRNA encodes two or more peptides or proteins that may be the same or different from each other. In certain embodiments, each peptide or protein encoded by the polycistronic mRNA contains at least one epitope of a selected antigen. In certain embodiments, the different peptides or proteins encoded by the polycistronic mRNA each contain at least one epitope of a different antigen. In any of the embodiments described herein, the at least one epitope may be at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9 or at least 10 epitopes of the antigen. The term "nucleobase" encompasses purines and pyrimidines, including the natural compounds adenine, thymine, guanine, cytosine, uracil, inosine, and their natural or synthetic analogs or derivatives. The term "administer / administration" refers to the act of injecting or otherwise physically delivering a substance that exists outside the body (such as the lipid nanoparticle compositions described herein) into a patient's body, such as by mucosal, intradermal, intravenous, intramuscular delivery, and / or any other physical delivery method described herein or known in the art. When treating a disease, disorder, affliction, or its symptoms, the administration of the substance is typically carried out after the onset of the disease, disorder, affliction, or its symptoms. When preventing a disease, disorder, affliction, or its symptoms, the administration of the substance is typically carried out before the onset of the disease, disorder, affliction, or its symptoms. "Effective amount" generally refers to an amount sufficient to reduce the severity and / or frequency of symptoms; eliminate symptoms and / or underlying causes; prevent the occurrence of symptoms and / or their underlying causes; and / or improve or remedy damage caused by or associated with a disease, disorder, or affliction, including, for example, damage caused by or associated with infections and neoplasia. In some embodiments, the effective amount is a therapeutically effective amount or a prophylactically effective amount. As used herein, the term "therapeutically effective amount" refers to an amount of an agent (such as a lipid nanoparticle composition described herein) sufficient to reduce and / or improve the severity and / or duration of a given disease, disorder, or affliction and / or its associated symptoms (such as an infectious disease, such as an infectious disease caused by a viral infection, or a neoplastic disease, such as cancer). The "therapeutically effective amount" of the substance / molecule / agent (such as a lipid nanoparticle composition described herein) of the present disclosure can vary depending on a number of factors, such as the disease state, age, sex, and weight of the individual, as well as the ability of the substance / molecule / agent to elicit the desired response in the individual. A therapeutically effective amount includes an amount where the therapeutic beneficial effects of the substance / molecule / agent outweigh any toxic or harmful effects. In certain embodiments, the term "therapeutically effective amount" refers to an amount of a lipid nanoparticle composition described herein or a therapeutic or prophylactic agent (such as a therapeutic mRNA) contained therein that is effective in treating a disease, disorder, or affliction in a subject or mammal. The term "treat / treating / treatment" refers to alleviating, in whole or in part, a disorder, disease, or affliction, or one or more symptoms associated with the disorder, disease, or affliction, or slowing or stopping the further progression or worsening of those symptoms, or alleviating or eradicating the cause of the disorder, disease, or affliction itself. The term "prevent / preventing / prevention" refers to reducing the likelihood of the onset (or recurrence) of a disease, disorder, affliction, or related symptoms. The term "side effect" encompasses the unwanted and / or adverse effects of a therapy (such as a prophylactic or therapeutic agent). An unwanted effect is not necessarily an adverse effect. The adverse effects of a therapy (such as a prophylactic or therapeutic agent) can be harmful, discomforting, or risky. Examples of side effects include diarrhea, cough, gastroenteritis, wheezing, nausea, vomiting, anorexia, abdominal colic, fever, pain, weight loss, dehydration, hair loss, dyspnea, insomnia, dizziness, mucositis, nerve and muscle effects, fatigue, dry mouth, loss of appetite, rash or swelling at the site of administration, flu-like symptoms such as fever, chills, and fatigue, digestive problems, and allergic reactions. There are numerous other unwanted effects experienced by patients and are known in the art. The present invention will be further elaborated in detail below in conjunction with specific embodiments. The embodiments are only used to explain the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the test methods used in the following embodiments are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, are reagents and materials that can be obtained from commercial sources. Table 1 shows some of the sequences related to the present invention; Table 2 shows some of the recombinant fusion sequences; Table 3 shows some of the amino acid sequences; Table 4 shows some of the mRNA sequences. Table 1 Sequences Table 2 Recombinant Fusion Sequences Table 3 Amino Acid Sequences Table 4 mRNA Sequences Example 1 Screening Sequences The amino acid sequence of the mature NGF protein is shown in SEQ ID NO. 2001; the amino acid sequence of the ProNGF protein is shown in SEQ ID NO. 2002; the wild-type mRNA sequence of the NGF protein is shown in SEQ ID NO. 27; the wild-type mRNA sequence of the ProNGF protein is shown in SEQ ID NO. 20. After codon optimization, sequences SEQ ID NO. 21-26 were designed. 1.1 Screening UTR Sequences The selected 5'UTR sequences are shown in SEQ ID NO. 1-15; the selected 3'UTR sequences are shown in SEQ ID NO. 16-19. Using one of the sequences SEQ ID NO. 20-27 as the ORF, it was combined with different 5'UTR sequences and different 3'UTR sequences respectively to obtain sequences SEQ ID NO. 34-513. Sequences SEQ ID NO. 34-93 were selected for testing, where the ORF was SEQ ID NO. 20 for all, and the 5'UTR sequences and 3'UTR sequences were different, to test the effects of different 5'UTR sequences and different 3'UTR sequences. The DNA sequences corresponding to the mRNA of sequences SEQ ID NO. 34-93 were synthesized by GenScript, and the specific process is as follows: (1) Synthesize the DNA sequence corresponding to the mRNA; (2) Construct the DNA sequence on the plasmid vector by homologous recombination; where the number of adenosines in polyA is 70-140. The plasmid vector containing the target gene was amplified and purified by Escherichia coli, and further linearized. After plasmid linearization, capped mRNA was prepared by the "one-pot method". Detection of mRNA Expression Level in Cells Transfection and expression: 293T cells were seeded in 6-well cell culture plates at a density of 0.6×10 6 cells / mL and cultured at 37°C under 5% CO2 conditions. The next day, the cells were transfected with mRNA, and the mass-volume ratio of mRNA to the transfection reagent jetMESSENGER was 1:2. Specifically, 200 μL of jetMESSENGER Buffer was added, 4 μg of mRNA was mixed in, 8 μL of the transfection reagent was added, and after mixing, it was left standing at room temperature for 15 min. Then it was added to the cells and cultured at 37°C under 5% CO2 conditions. The medium was changed 6 h after transfection, and the supernatant was collected 24 h after transfection. The expression level of NGF in the supernatant was measured by ELISA. The measured results are shown in Table 5. Table 5 Expression results of mRNA in cells As can be seen from Table 5, after the 5'UTR sequence and 3'UTR used in the present invention were used to prepare mRNA, both could normally express proteins in cells. When the ORF sequence was SEQ ID NO.20, there were obvious differences in the expression levels of mRNAs composed of different 5'UTR sequences and different 3'UTRs; from the above results, when the 5'UTR sequence was SEQ ID NO.3 and the 3'UTR sequence was SEQ ID NO.16, the expression of mRNA was the best. Therefore, in subsequent studies, the 5'UTR sequence of SEQ ID NO.3 and the 3'UTR sequence of SEQ ID NO.16 were used. 1.2 Screening of ORF sequences The preparation, transfection and expression of mRNA refer to 1.1. Among them, the ORF sequences in mRNA were SEQ ID NO: 20-26 respectively; the 5'UTR sequences were all SEQ ID NO.3, and the 3'UTR sequences were all SEQ ID NO.16, that is, the sequences SEQ ID NO: 36, 96, 156, 216, 276, 336, 396. The measured expression results are shown in Table 6. Table 6 Expression results of mRNA in cells As can be seen from Table 6, multiple mRNAs prepared in the present invention can all express the target protein in cells, and the expression levels are good, all better than the wild-type sequence SEQ ID NO.20; especially the sequences SEQ ID NO.96, SEQ ID NO.156 and SEQ ID NO.216 have higher expression levels. 1.3 Screening of recombinant fusion sequences To further improve the stability and expression effect of mRNA, multiple groups of recombinant fusion sequences were designed for screening mRNA with better effects. The synthesis, transfection, and expression detection of the recombinant fusion sequences refer to 1.1. The measured results are shown in Table 7. Table 7 Expression results of mRNA in cells As can be seen from Table 7, for the sequences after recombinant fusion, there is a certain degree of improvement in the protein expression level compared with the sequences without recombinant fusion, indicating that recombinant fusion of the ORF can improve the expression level of mRNA, and the protein expression level can even be increased to more than 1.5 times. Example 2 Effect of mRNA-expressed protein on PC12 cells The screened mRNA was used to express protein in cells to obtain cell supernatant containing the target protein, and its effect on PC12 cells was tested. The test method is as follows: (1) Preparation of cell supernatant containing NGF protein mRNA was prepared using the screened sequence, transfected into 293T cells for expression according to the method in Example 1. After 24 hours of expression, the cell supernatant containing NGF protein was collected and reserved. (2) Testing the effect on PC12 cells PC12 cells were seeded in a 6-well plate coated with rat tail collagenase at a density of 1×10 5 cells / mL and cultured at 37°C under 5% CO2. After 24 hours of culture, the cell medium was removed, and the cells were rinsed twice with PBS. Then, the cells were cultured with cell supernatant containing or not containing NGF protein for 5 days and photographed. The final concentration of NGF protein used was 50 ng / μL. The growth of PC12 cells in different media was observed. The length of neurites was determined by comparing the length of neurites and the average diameter of cell bodies, and reported as neurite length / cell body diameter. The results are shown in Figure 1. As can be seen from Figure 1 and Figure 8, compared with the control group, in the treatment group with cell supernatant containing mRNA-expressed protein added, the neurite length / cell body diameter all increased. Example 3 Promotion of proliferation and migration of HCEC by mRNA-expressed protein (1) Preparation of cell supernatant containing NGF protein Refer to (1) in Example 2. (2) Testing the effect on HCEC Corneal epithelial cells HCEC were seeded at 3.5×10 5The cells were plated at a density of 100 / mL in a 6-well cell culture plate and cultured at 37°C and 5% CO2. After the cells were confluent, they were starved for 8 h with serum-free medium, scratched with a sterile 200 μL pipette tip, rinsed 3 times with PBS, and cultured with cell supernatant containing or without NGF protein. The final concentration of NGF was 50 ng / μL. Pictures were taken at 24 and 48 h to calculate the migration rate. The measured results are shown in Figures 2 and 9. Compared with the control, the wound healing rate was significantly increased in the group treated with cell supernatant containing mRNA expression protein. Example 4 Encapsulation and in vivo expression of mRNA 4.1 mRNA encapsulation The main components of LNP include cationic lipid, cholesterol, DSPC and DMG-PEG2000, with molar ratios of 48.5%, 38.9%, 11.1% and 1.5% respectively. Among them, the cationic lipid is selected from one or more combinations of SM102, MC3, DOTAP, ALC-0315, H1, H2, H3, H4, H5 and H6. 4.1.1 Lipid-ethanol solution: Dissolve the required cationic lipids, cholesterol, DSPC and DMG-PEG2000 in anhydrous ethanol at a molar ratio to prepare a lipid-ethanol solution with a total lipid concentration of 8 mM for later use. 4.1.2 mRNA-acetate buffer: Dilute the mRNA stock solution with acetate buffer solution (200 mM, pH 5.0) to an appropriate concentration for later use. 4.1.3 Encapsulation: The mRNA-buffer phase and the lipid-ethanol phase were mixed using a microfluidic instrument (syringe pump: SPM, Duco Industry; mixing chip: LNP-B0, FluidicLab) with a nitrogen-phosphorus ratio of 4.8 or other, a flow rate ratio of 3:1 (buffer phase / ethanol phase), and a total flow rate of 3.6 mL / min; the mixed sample was dialyzed (25 or 30 kDa MwCO) at 4°C overnight against 34 times the volume of Tris saline buffer solution (20.5 mM, pH 7.5, containing 8.95% sucrose) to obtain LNPs encapsulating mRNA. The mass ratio of LNP to mRNA is approximately 5:1, 10:1, 15:1, and 20:1. The dosage ratios are shown in Table 8.1 and Table 8.2. To ensure accurate weighing of each component, the weighing and preparation can be scaled up in equal proportions. Table 8.1 Components and dosage Table 8.2 Components and dosage 4.2 In Vivo Expression in Rats mRNA-LNP (50 ng / μL × 1200 μL) was injected into the caudal vein of rats. After administration, blood samples of mice were collected at 0.5, 1, 2, 4, 6, 8, 10, 12, 24, and 32 h, and the concentration of NGF in serum was detected. The results of pharmacokinetic parameters are shown in Table 9. Table 9 The half-life of the recombinant fusion mRNA was significantly prolonged. With a single administration, the effect could be maintained for a long time, which was beneficial for preparing a long-acting drug, reducing the usage frequency, and improving convenience and patient compliance. Example 5 Pharmacodynamic Experiment of a Mouse Model of Benzalkonium Chloride-Induced Neurotrophic Keratitis Forty healthy female C57BL / 6J mice were randomly selected, and a mouse model of neurotrophic keratitis was induced with benzalkonium chloride (0.1%, both eyes were modeled, 2 times / day, 5 μL / eye). The first day of modeling was D1. On D7, 30 successfully modeled animals (with a significant decrease in corneal sensation) were randomly divided into 5 groups according to corneal sensation: model control group, positive control group, high-dose administration group (Qid), medium-dose administration group (Bid), and low-dose administration group (Qd). From D8 to D21, all animals maintained the modeling (the method was the same as before). The model control group instilled the mRNA-LNP dilution solution (20.5 mM Tris buffer containing 8.95% sucrose, pH 7.5) into both eyes 4 times a day, 5 μL per eye each time; the positive control group instilled Recombinant human beta NGF protein with a concentration of 40 ng / μL into both eyes 4 times a day, 5 μL per eye each time; the Qid, Bid, and Qd groups all instilled mRNA-LNP (SEQ ID NO.96, SM102) with a concentration of 500 ng / μL into the eyes, 5 μL per eye each time. Among them, the high-dose administration group (Qid) was the group that instilled mRNA-LNP into the eyes 4 times a day; the medium-dose administration group (Bid) was the group that instilled mRNA-LNP into the eyes 2 times a day; the low-dose administration group (Qd) was the group that instilled mRNA-LNP into the eyes 1 time a day. During the experiment, animals were generally clinically observed daily and weighed 2 times a week; on D1, D7, D14, and D21, slit lamp examination, corneal sensation detection, and corneal fluorescein sodium staining test were performed on each group of animals. The experimental data were the mean ± standard error of each group of mice. 5.1 General Clinical Indexes At least 1 observation was made every day during the experiment, including but not limited to appearance signs, hair, general behavior activities, mental state, glandular secretion, skin and mucosal color, respiratory state, fecal traits, genitalia, death, etc. The results showed that no abnormal clinical reactions were observed in each group of animals. 5.2 Body weight During the experiment, there were no statistically significant differences in body weight among groups at each time point (P > 0.05), as shown in Figure 3. 5.3 Corneal sensation Before modeling (D1), there were no statistically significant differences in corneal sensation among groups (P > 0.05). Before administration (D7), the corneal sensation in each group was significantly lower than that at D1, but there were no statistically significant differences among groups (P > 0.05), indicating that bilateral eye drops of benzalkonium chloride solution for modeling could reduce the corneal sensation of mice, and there were no differences in the lesion degrees of each group of mice before administration. Data of two eyes were collected from each mouse, and each group of data was the mean ± standard error of the data collected from each mouse within the group. At D14 and D21, the corneal sensation of the Qd, Bid, Qid, and positive control groups in the mRNA-LNP administration group was significantly higher than that of the model control group (P ≤ 0.05). There were no significant differences in corneal sensation between the Qd and Bid administration groups and the positive control group. The corneal sensation recovery effect of the Qid administration group was more obvious, as shown in Figure 4. 5.4 Corneal fluorescein sodium staining index Before modeling (D1), the IOD value of the corneal staining area and the area of the corneal staining area (evaluation indexes of corneal fluorescein sodium staining) of each group of animals were both 0. Before administration (D7), the evaluation indexes of corneal fluorescein sodium staining among groups increased significantly, and there were no statistically significant differences among groups (P > 0.05), indicating that bilateral eye drops of benzalkonium chloride solution for modeling could cause corneal epithelial damage in mice, and the lesion degrees of each group of mice before administration were similar. Data of two eyes were collected from each mouse, and each group of data was the mean ± standard error of the data collected from each mouse within the group. At D14 and D21, the evaluation indexes of corneal fluorescein sodium staining in the Qd, Bid, Qid, and positive control groups of the mRNA-LNP administration group were significantly lower than those of the model control group (P ≤ 0.05); at D14, there were no significant differences in the corneal staining area and the IOD value of the corneal staining area between the Qd administration group and the positive control group, and the corneal sensation recovery effects of the Qid and Bid administration groups were better, indicating that the corneal sensation recovery speed of mice in the Qid and Bid administration groups was faster during the period from D7 to D14, as shown in Figures 5 - 6. 5.5 Corneal neuropathy At D22, the mice were sacrificed and the left eyes were taken for detection. The evaluation indexes of corneal neuropathy in the Qd, Bid, Qid, and positive control groups of the mRNA-LNP administration group were significantly lower than those of the model control group (P ≤ 0.05), indicating that Qd, Bid, and Qid in the mRNA-LNP administration group showed good therapeutic effects on corneal neuropathy in mice, and the effects were equivalent to those of the positive control group, as shown in Figure 7. In summary, the benzalkonium chloride solution eye drops successfully induced a neurotrophic keratitis model in mice. The Qd, Bid, and Qid groups in the mRNA-LNP administration group showed significant improvement in corneal hypoesthesia and corneal epithelial damage in model mice after continuous eye drops for 7 days and 14 days. Among them, within the first week of administration, the Bid and Qid administration groups showed a faster recovery rate for corneal sensation in mice. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description and ideas. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An mRNA encoding a nerve growth factor, characterized in that The mRNA comprises a coding region; the coding region comprises one or more ORFs; the ORFs are selected from SEQ ID NOs: 20-27 or a sequence having a similarity of at least 98% to one of SEQ ID NOs: 20-27.

2. An mRNA encoding a nerve growth factor, characterized in that: The mRNA comprises a coding region; the coding region comprises one or more ORFs; the ORFs are selected from SEQ ID NOs: 1041-1043, SEQ ID NOs: 1091-1093, SEQ ID NOs: 1131-1133, or a sequence having at least 98% similarity to one of SEQ ID NOs: 1041-1043, SEQ ID NOs: 1091-1093, SEQ ID NOs: 1131-1133.

3. The mRNA encoding nerve growth factor according to claim 1 or 2, characterized in that When the coding region comprises at least two ORFs, the sequences of the ORFs may be the same or different; any one of SEQ ID NO: 28, 29 or 33 is used as an intervening sequence between each ORF; Alternatively, when the coding region comprises at least three ORFs, the spacer sequences may be the same or different.

4. The mRNA encoding nerve growth factor according to claim 3, characterized in that When the coding region comprises at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1011-1013, 1021-1023, 1031-1033, 1051-1053, 1061-1063, 1071-1073, 1081-1083, 1101-1103, 1111-1113, 1121-1123, and 1131-1133.

5. The mRNA encoding the nerve growth factor according to any one of claims 1 to 4, characterized in that: The mRNA further comprises a 5'UTR, the sequence of which is selected from any one of SEQ ID NOs: 1-15.

6. The mRNA encoding the nerve growth factor according to any one of claims 1 to 5, characterized in that: The mRNA further comprises a 3'UTR, the sequence of which is selected from any one of SEQ ID NOs: 16-19.

7. The mRNA encoding the nerve growth factor according to any one of claims 1 to 6, characterized in that: The mRNA also includes poly A, which contains at least 70 adenosines.

8. The mRNA encoding nerve growth factor according to claim 7, characterized in that: The poly A comprises 70-140 adenosines, or 70-120 adenosines, or 80-120 adenosines, or 90-120 adenosines, or 100-140 adenosines, or 100-120 adenosines.

9. The mRNA encoding the nerve growth factor according to any one of claims 1 to 8, characterized in that: The mRNA also includes a 5' cap structure.

10. The mRNA encoding nerve growth factor according to claim 9, characterized in that: The 5' cap structure is selected from Cap0, Cap1, Cap2 or a structure as shown in Formula I: Where R1 is H, C 1-4 Alkyl, C 1-4 Halogenated alkyl, phenyl, C 1-4 Alkyl substituted phenyl, halogenated phenyl, benzyl, C 1-4 Alkyl-substituted benzyl or halogenated benzyl; R2 is OH, halogen, OC 1-4 Alkyl, C 1-4 Alkyl, C 1-4 Alkoxy, C 1-4 Haloalkyl, C 1-4 Alkoxy substituted C 1-4 Alkyl, C 1-4 Alkylamino substituted C 1-4 Alkyl, C 1-4 Amide substituted C 1-4 Alkyl, benzyloxy, halogenated benzyloxy, benzyloxy substituted C 1-4 Alkyl or halogenated benzyloxy substituted C 1-4 alkyl; R3 and R4 are each independently H, C 1-4 Alkyl or C 1-4 Halogenated alkyl. R5 is H, C 1-4 Alkoxy, F, Cl, I or N3; R6 is H, C 1-4 Alkyl, C 1-4 Alkenyl, C 1-4 Alkynyl, phenyl, C 1-4 Alkyl substituted phenyl, halogenated phenyl, benzyl, C 1- 4. Alkyl-substituted benzyl or halogenated benzyl; B1 and B2 are each independently a base G, A, U or C, and the substituted base includes but is not limited to 6-MeA, 5-MeU or 5-MeC.

11. The mRNA encoding the nerve growth factor according to any one of claims 1 to 10, characterized in that: The mRNA comprises at least one chemically modified nucleoside.

12. The mRNA encoding nerve growth factor according to claim 11, characterized in that: The chemically modified nucleoside is selected from pseudouracil, N1-methyl-pseudouracil, 1-ethylpseudouracil, 2-thiouracil, 4′-thiouracil, 5-methyluracil or 5-methoxyuracil, or any combination thereof.

13. The mRNA encoding nerve growth factor according to claim 11 or 12, characterized in that: The chemically modified nucleoside is selected from one of the following situations: (1) The chemically modified nucleoside is selected from pseudouracil and / or N1-methyl-pseudouracil; (2) The chemically modified nucleoside is selected from 1-ethylpseudouracil; (3) The chemically modified nucleoside is selected from 2-thiouracil; (4) The chemically modified nucleoside is selected from 4′-thiouracil; (5) The chemically modified nucleoside is selected from 5-methyluracil; (6) The chemically modified nucleoside is selected from 5-methoxyuracil.

14. The mRNA encoding the nerve growth factor according to any one of claims 11 to 13, characterized in that: The proportion of chemically modified nucleosides in the mRNA is 10-100%, or 20-100%, or 30-100%, or 40-100%, or 50-100%, or 60-100%, or 70-100%, or 80-100%, or 90-100%, or 50-98%, or 50-95%, or 60-95%, or 70-95%, or 80-95%, or 90-95%, or 70-90%, or 80-90%.

15. The mRNA encoding the nerve growth factor according to any one of claims 1 to 14, characterized in that: The amino acid sequence encoded by the mRNA comprises SEQ ID NO.2001 or SEQ ID NO.2002.

16. The mRNA encoding the nerve growth factor according to any one of claims 1 to 15, characterized in that: The amino acid sequence encoded by the mRNA is any one of SEQ ID NO.2001-2013; Or the amino acid sequence encoded by the mRNA is as SEQ ID NO.2014.

17. An mRNA encoding a nerve growth factor, characterized in that: The mRNA comprises: (ii) 5'UTR; the 5'UTR is selected from any one of SEQ ID NOs: 1-15; (iii) a coding region; the coding region comprises one or more ORFs; the ORFs are selected from SEQ ID NOs: 20-27 or sequences having at least 98% similarity to one of SEQ ID NOs: 20-27; (iv) 3'UTR; the 3'UTR is selected from any one of SEQ ID NOs: 16-19; (v) poly A; the poly A comprises at least 70 adenosines.

18. The mRNA encoding nerve growth factor according to claim 17, characterized in that: The ORF is one of the following: (1) the ORF is SEQ ID NO: 20; (2) the ORF is SEQ ID NO: 21; (3) the ORF is SEQ ID NO: 22; (4) the ORF is SEQ ID NO: 23; (5) the ORF is SEQ ID NO: 24; (6) the ORF is SEQ ID NO: 25; (7) the ORF is SEQ ID NO: 26; (8) the ORF is SEQ ID NO:

27.

19. The mRNA encoding nerve growth factor according to claim 17 or 18, characterized in that The 5'UTR sequence is one of the following: (1) the 5'UTR sequence is SEQ ID NO: 1; (2) the 5'UTR sequence is SEQ ID NO: 2; (3) the 5'UTR sequence is SEQ ID NO: 3; (4) the 5'UTR sequence is SEQ ID NO: 4; (5) the 5'UTR sequence is SEQ ID NO: 5; (6) the 5'UTR sequence is SEQ ID NO: 6; (7) the 5'UTR sequence is SEQ ID NO: 7; (8) the 5'UTR sequence is SEQ ID NO: 8; (9) the 5'UTR sequence is SEQ ID NO: 9; (10) the 5'UTR sequence is SEQ ID NO: 10; (11) the 5'UTR sequence is SEQ ID NO: 11; (12) the 5'UTR sequence is SEQ ID NO: 12; (13) the 5'UTR sequence is SEQ ID NO: 13; (14) the 5'UTR sequence is SEQ ID NO: 14; (15) the 5'UTR sequence is SEQ ID NO: ID NO:

15.

20. The mRNA encoding the nerve growth factor according to any one of claims 17 to 19, characterized in that: The sequence of the 3'UTR is one of the following: (1) the 3'UTR sequence is SEQ ID NO: 16; (2) the 3'UTR sequence is SEQ ID NO: 17; (3) the 3'UTR sequence is SEQ ID NO: 18; (4) the 3'UTR sequence is SEQ ID NO:

19.

21. The mRNA encoding the nerve growth factor according to any one of claims 17 to 20, characterized in that: When the coding region comprises at least two ORFs, the sequences of the ORFs may be the same or different; any one of SEQ ID NO: 28, 29 or 33 is used as an interval sequence between each ORF.

22. The mRNA encoding nerve growth factor according to claim 21, characterized in that When the coding region comprises at least three ORFs, the spacer sequences may be the same or different; When the coding region comprises at least two ORFs, the coding region is selected from any one of SEQ ID NOs: 1011-1013, 1021-1023, 1031-1033, 1041-1043, 1051-1053, 1061-1063, 1071-1073, 1081-1083, 1091-1093, 1101-1103, 1111-1113, 1121-1123, and 1131-1133.

23. The mRNA encoding the nerve growth factor according to any one of claims 1 to 22, characterized in that: The mRNA further comprises (i) a 5' cap structure, wherein the 5' cap structure is selected from Cap0, Cap1, Cap2 or a structure as shown in Formula I: Where R1 is H, C 1-4 Alkyl, C 1-4 Alkoxy, C 1-4 Halogenated alkyl, phenyl, C 1-4 Alkyl substituted phenyl, halogenated phenyl, benzyl, C 1-4 Alkyl-substituted benzyl or halogenated benzyl; R2 is OH, C 1-4 Alkyl, C 1-4 Haloalkyl, C 1-4 Alkoxy substituted C 1-4 Alkyl, C 1-4 Alkylamino substituted C 1-4 Alkyl, C 1-4 Amide substituted C 1-4 Alkyl, benzyloxy, halogenated benzyloxy, benzyloxy substituted C 1-4 Alkyl or halogenated benzyloxy substituted C 1-4 alkyl; R3 and R4 are each independently H, C 1-4 Alkyl or C 1-4 Haloalkyl; R5 is H, C 1-4 Alkoxy, F, Cl, I or N3; R6 is H, C 1-4 Alkyl, C 1-4 Alkenyl, C 1-4 Alkynyl, phenyl, C 1-4 Alkyl substituted phenyl, halogenated phenyl, benzyl, C 1- 4. Alkyl-substituted benzyl or halogenated benzyl; B1 and B2 are each independently a base G, A, U or C, and the substituted base includes but is not limited to 6-MeA, 5-MeU or 5-MeC.

24. The mRNA encoding nerve growth factor according to claim 23, characterized in that The R6 is any one of the following a1-a6: a1. R6 is H, C 1-4 Alkyl, C 1-4 Alkenyl, C 1-4 Alkynyl, phenyl, halophenyl, benzyl, or halobenzyl; a2. R6 is H, C 1-4 Alkyl, phenyl, halophenyl, benzyl or halobenzyl; a3. R6 is H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, phenyl, benzyl, 3-fluorophenyl, 4-fluorophenyl, 3,5-difluorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3,5-dichlorophenyl, 3-fluorobenzyl, 4-fluorobenzyl, 3,5-difluorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl or 3,5-dichlorobenzyl; a4. R6 is H, methyl, ethyl, propyl, isopropyl, phenyl, benzyl, 3-fluorophenyl, 4-fluorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3-fluorobenzyl, 4-fluorobenzyl, 3-chlorobenzyl or 4-chlorobenzyl; a5. R6 is H, methyl, ethyl, isopropyl, phenyl, benzyl, 4-fluorophenyl, 4-chlorophenyl, 4-fluorobenzyl or 4-chlorobenzyl; a6. R6 is H, methyl, ethyl, isopropyl, phenyl, benzyl, 4-fluorophenyl or 4-fluorobenzyl.

25. The mRNA encoding nerve growth factor according to claim 23 or 24, characterized in that: The R3 and R4 are any one of the following b1-b4: b1. R3 and R4 are each independently H, methyl, ethyl, isopropyl, tert-butyl, trifluoromethyl, trifluoroethyl or trifluoroisopropyl. b2. R3 and R4 are each independently H, methyl, ethyl, isopropyl, trifluoromethyl or trifluoroethyl. b3. R3 and R4 are each independently H, methyl, ethyl or trifluoromethyl. b4. R3 and R4 are each independently H, methyl or trifluoromethyl.

26. The mRNA encoding the nerve growth factor according to any one of claims 23 to 25, characterized in that: The R2 is any one of the following c1-c4: c1. R2 is OH, C 1-4 Alkyl, C 1-4 Alkoxy, C 1-4 Haloalkyl, C 1-4 Alkoxy substituted C 1-4 Alkyl, C 1-4 Alkylamino substituted C 1-4 Alkyl, C 1-4 Amide substituted C 1-4 Alkyl, benzyloxy or benzyloxy substituted C 1-4 alkyl; c2. R2 is OH, C 1-4 Alkyl, C 1-4 Alkoxy, C 1-4 Haloalkyl, C 1-3 Alkoxy substituted C 1-3 Alkyl, C 1-3 Alkylamino substituted C 1-3 Alkyl, C 1-3 Amide substituted C 1-3 Alkyl, benzyloxy or benzyloxy substituted C 1-3 alkyl; c3. R2 is OH, C 1-4 Alkyl, C 1-4 Alkoxy, C 1-4 Haloalkyl, C 1-3 Alkoxy substituted C 1-3 Alkyl, C 1-3 Alkylamino substituted C 1-3 Alkyl or C 1-3 Amide substituted C 1-3 alkyl; c4. R2 is OH, C 1-4 Alkyl, C 1-4 Alkoxy, C 1-4 Haloalkyl or C 1-3 Alkoxy substituted C 1-3 alkyl.

27. The mRNA encoding the nerve growth factor according to any one of claims 23 to 26, characterized in that: The R1 is H, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, trifluoromethyl, trifluoroethyl, trifluoropropyl, trifluoroisopropyl, phenyl, 2-methyl-phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2,6-dimethyl-phenyl, 3,5-dimethyl-phenyl, 2-ethyl-phenyl, 3-ethyl-phenyl, 4-ethyl-phenyl, 2,6-diethyl-phenyl, 3,5-diethyl-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2,6-chloro-phenyl, 3,5-chloro-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4 phenyl, 2,6-fluoro-phenyl, 3,5-fluoro-phenyl, benzyl, 2-methyl-benzyl, 3-methyl-benzyl, 4-methyl-benzyl, 2,6-dimethyl-benzyl, 3,5-dimethyl-benzyl, 2-ethyl-benzyl, 3-ethyl-benzyl, 4-ethyl-benzyl, 2,6-diethyl-benzyl, 3,5-diethyl-benzyl, 2-chloro-benzyl, 3-chloro-benzyl, 4-chloro-benzyl, 2,6-chloro-benzyl, 3,5-chloro-benzyl, 2-fluoro-benzyl, 3-fluoro-benzyl, 4-fluoro-benzyl, 2,6-fluoro-benzyl or 3,5-fluoro-benzyl.

28. A composition, characterized in that Comprising the mRNA encoding the nerve growth factor according to any one of claims 1 to 27 and a delivery agent.

29. The composition according to claim 28, characterized in that The delivery agent comprises lipid nanoparticles; the lipid nanoparticles contain: cationic lipids, phospholipids, cholesterol and PEG lipids.

30. The composition according to claim 29, characterized in that The molar ratio of the cationic lipid, phospholipid, cholesterol and PEG lipid in the lipid nanoparticles is any one of the following c1-c4: c1. The molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid is 30-60:0-30:18.5-48.5:0-10; c2 The molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid is 35-55:0-25:20-45:0.5-8; c3 the molar ratio of cationic lipid, phospholipid, cholesterol and PEG lipid is 40-52:5-20:25-40:0.5-5; The molar ratio of c4 cationic lipid, phospholipid, cholesterol and PEG lipid is 45-52:8-15:30-40:1-5; The molar ratio of c5 cationic lipid, phospholipid, cholesterol and PEG lipid is 50:10:38.5:1.5 or 48.5:11.1:38.9:1.

5.

31. A composition according to any one of claims 28 to 30, characterized in that The cationic lipid is shown in Formula II: wherein n0 is an integer from 0 to 4; n1 is an integer from 2 to 7; n2 is an integer from 4 to 10; n3 is an integer from 2 to 8; n4 is an integer from 2 to 8; n5 is an integer from 2 to 8; Or, the cationic lipid is one or more combinations of SM102, MC3, DOTAP, ALC-0315, H1, H2, H3, H4, H5, and H6.

32. A composition according to any one of claims 28 to 31, characterized in that The phospholipid is DSPC or DOPE; the molecular weight of the PEG lipid is PEG, PEG-modified compound or a mixture thereof with a molecular weight of 1000Da to 20kDa.

33. A composition according to any one of claims 28 to 32, characterized in that The composition further includes a pharmaceutically acceptable excipient.

34. Use of the mRNA encoding nerve growth factor according to any one of claims 1 to 27 or the composition according to any one of claims 28 to 33 in the preparation of a medicament for preventing and / or treating diseases including but not limited to corneal lesions, optic neuropathy, conjunctival lesions, limbal stem cell deficiency, and dry eye.

35. The use according to claim 34, characterized in that: The corneal lesion is selected from keratoconus, phototoxic keratopathy, persistent corneal epithelial defects, corneal ulcers, corneal dystrophy and degeneration, keratoconjunctivitis sicca or neurotrophic keratitis; The optic neuropathy is selected from glaucoma and ischemic optic neuropathy, degenerative, traumatic, Leber hereditary optic neuropathy and congenital optic atrophy; The dry eye syndrome is selected from the group consisting of aqueous deficiency dry eye, lipid abnormality dry eye, mucin abnormality dry eye, tear dynamics abnormality dry eye and mixed dry eye.

36. Use of the mRNA encoding nerve growth factor according to any one of claims 1 to 27 or the composition according to any one of claims 28 to 33 in the preparation of a drug for preventing and / or treating peripheral neuropathy and idiopathic facial paralysis.

37. The use according to claim 36, characterized in that: The peripheral neuropathy includes, but is not limited to, AIDS-related sensory neuropathy, diabetic polyneuropathy, toxic peripheral neuropathy, and traumatic peripheral nerve injury.

38. The use according to any one of claims 34 or 37, characterized in that: The medicine is a medicine for local use.

39. The use according to claim 38, characterized in that The medicine is an injection, a local external preparation, a nasal spray or an eye drop.

40. A method for preventing and / or treating corneal pathology, optic neuropathy, conjunctival pathology, limbal stem cell deficiency or dry eye, characterized in that: A therapeutically effective amount of the mRNA encoding the nerve growth factor according to any one of claims 1 to 27 or the composition according to any one of claims 28 to 33 is administered to a subject in need thereof.

41. The method according to claim 40, characterized in that Also included is administering an additional agent to the subject.

42. The method according to claim 40, characterized in that The corneal pathological condition is selected from keratoconus, phototoxic keratopathy, persistent epithelial defects, corneal ulcers, corneal dystrophy and degeneration, keratoconjunctivitis sicca, or neurotrophic keratitis; The optic neuropathy is selected from glaucoma and ischemic, degenerative, traumatic, hereditary and congenital neuropathies.

Images