TRIAC (3,3',5-TRIIODTHYRACETIC ACID) FOR THE TREATMENT OF ALPHA-THALASSEMIA

Description

Technical Field

[0001] The present invention belongs to the technical field of thalassemia, and particularly relates to an application of thyroid hormones and its analogues in preparation for treating alpha-thalassemia.Background of the Invention

[0002] The thalassemias are the most common monogenic diseases in the world, which have great influences on human health. These inherited disorders of hemoglobin synthesis are characterized by a reduced production of globin chains of hemoglobin. Worldwide, the most important forms are the alpha- and beta-thalassemias, which affect production of the alpha-globin and beta-globin chains, respectively. The number of alpha-thalassemia gene carriers is higher than that of beta-thalassemia gene carriers, and the number of patients with alpha-thalassemia intermediate (also known as HbH disease) and alpha-thalassemia major (also known as Hemoglobin Bart's hydrops fetalis) in China is much higher than that in other countries and regions of the world, so China is a veritable "hardest hit area" of alpha-thalassemia. However, there is no mature and effective method for treating such diseases so far. Therefore, patients with alpha-thalassemia face huge unmet medical demands.

[0003] Alpha-thalassemia refers to a hemolytic anemia caused by the destruction of erythrocytes due to a decrease of the synthesis of alpha-globin chains. There are four types of alpha-thalassemia, which are as follows: (1) silent alpha-carriers; (2) alpha-thalassemia minor; (3) alpha-thalassemia intermediate (also known as HbH disease); and (4) alpha-thalassemia major (also known as Hemoglobin Bart's hydrops fetalis). The patients with silent alpha-carriers and alpha-thalassemia minor do not need special treatment. However, some patients with HbH disease need blood transfusion. For infants with Hemoglobin Bart's hydrops fetalis, some hospitals have reported that intrauterine blood transfusion can relieve their symptoms, but up to now, there is still no effective treatment.

[0004] However, blood transfusion treatment may bring the following problems: 1. Blood transfusion will lead to iron overload to damage multiple organs, mainly affecting heart, liver, pancreas and various endocrine organs; 2. Blood transfusion will cause fever, chills, rash and other adverse effects, and will lead to acute hemolysis, tracheal contraction and blood pressure drop in severe cases; 3. Blood transfusion may pose a risk of infectious diseases through blood; 4. Intrauterine blood transfusion has high requirements and difficulty in technique, which makes it difficult to be widely used. 5. Blood transfusion has high cost, which will cause an economic burden especially for patients who need lifelong blood transfusion.

[0005] Harteveld Cornelis L et al. (2010) further describes the origin and available treatment for alpha-thalassemia in the article "α-thalassemia", Orphanet Jornal of Rare Diseases, Biomed Central LTD, LO, vol. 5, no. 1, 28 May 2010, page 13. The international patent application WO2018 / 140934 A1 suggests possible treatments for thalassemia by administering one eukaryotic translation initiation factor 2-alpha kinase 1.

[0006] Zeta-globin is a type of alpha-like globin expressed only in an embryonic stage, which also has an oxygen-carrying function. A gene encoding this protein is well preserved in most patients with alpha-thalassemia, and its expression is gradually silenced during embryonic development. Studies have proved that in a lethal alpha-thalassemia mouse model, re-expression of zeta-globin by a transgenic method can fully restore normal development of the alpha-thalassemia mouse. Therefore, reactivation of zeta-globin gene expression in patients to replace the defective alpha-globin is expected to be an effective method for treating alpha-thalassemia. However, pharmacologic compounds capable of reactivating zeta-globin gene expression have not been yet available so far.

[0007] Zhenning et al., (2001) also suggested that the replacement of human and beta globins with their embryonic zeta globin homologues may exhibit properties that are similar to those of the adult-stage globins and may have clinical implications in the treatment of alpha and beta thalassemia ("Functional effects of replacing human [alpha]-and [beta]-globins with their embryonic globin homologues in defined haemoglobin heterotetramers" British Journal of Haematology, Jonh Wiley, Hoboken, USA, vol. 109, 2001-12-24, pages 882-890).

[0008] In 1978, Fuhr J. E. et al. suggested that L-Thyroxine stimulates hemoglobin synthesis in fetal erythroid cells in the article "Control of Hemoglobin Synthesis in Fetal Erythroid cells by L-Thyroxine" American Journal of Hematology, vol. 5, pages 163-168.Summary of the Invention

[0009] The present invention is defined in the appended claims. Embodiments not falling within the subject-matter of the claims are not considered to be part of the invention.

[0010] To overcome the shortcomings of the prior art, the primary purpose of the present disclosure is to provide an application of thyroid hormones and its analogues in preparation for treating alpha-thalassemia.

[0011] A second purpose of the present disclosure is to provide an application of thyroid hormones and its analogues in preparation for regulating expression of zeta-globin gene.

[0012] To achieve the above purposes, the present invention provides the solution provided in claim 1. J

[0013] Triac (also known as Tiratricol or 3,3',5-triiodothyroacetic acid) (chemical name: 2-[4-(4-hydroxy-3-iodophenoxy)-3,5-diiodophenyl] acetic acid; molecular formula: C 14 H 9 I 3 O 4 ) is a thyroid hormone analogue for treating patients with thyroid hormone resistance syndrome, hyperlipidemia, localized lipodystrophy and obesity. In addition, Triac has also displayed therapeutic potential for the treatment of Allan-Herndon-Dudley syndrome.

[0014] The inventor has found that during the differentiation of K562 cells, Triac can up-regulate the expression of zeta-globin gene (HBZ). Furthermore, Triac could also dramatically induce zeta-globin gene (hbae5) expression in zebrafish. In addition, the inventor has also found that the thyroid hormones (3,3',5-Triiodo-L-thyronine, referred to as T3 or 3,3',5,5'-tetraiodothyronine, referred to as T4) had a similar effect. Therefore, the inventor discovered for the first time that the thyroid hormone analogue (Triac) and thyroid hormones (T3 or T4) could induce zeta-globin gene expression both in vitro and in vivo, which may allow development of new therapies for alpha-thalassemia.

[0015] Specifically, Triac was purchased from Selleck Biotech Co., Ltd. of the United States, T3 (3,3',5-Triiodo-L-thyronine) was purchased from Sigma Company, and T4 (3,3',5,5'-tetraiodothyronine) was purchased from Biological Engineering (Shanghai) Ltd., Co.

[0016] By adopting the above solutions, the present invention has the following beneficial effects: according to the present invention, thyroid hormones (T3 and T4) and thyroid hormone analogue (Triac) act as a potent inducer of zeta-globin expression, which may sever as a new potential therapeutic option for patients with alpha-thalassemia. It provides an economical, safe and effective method for the treatment of alpha-thalassemia, and can be widely used.Brief description of the Drawings

[0017] Fig. 1. The thyroid hormone analogue (Triac) induced zeta-globin gene (HBZ) expression in hemin-treated K562 cells. Fig. 2. WISH assay shows Triac, T3 or T4 induced zeta-globin gene (hbae5) expression in zebrafish embryos. Fig. 3. qPCR shows Triac, T3 or T4 induced zeta-globin gene (hbae5) expression in zebrafish embryos. Detailed Description of Embodiments

[0018] The present description relates to an application of thyroid hormones and its analogues in preparation for treating alpha-thalassemia.Experimental materials:

[0019] K562 cells were cultured in RPMI 1640 medium supplemented with 10% (v / v) fetal bovine serum; Hemin was dissolved into 0.2 mol / L NaOH solution, and the working concentration for treating K562 cells is 20 µmol / L; Triac, T3 and T4 were dissolved into dimethyl sulfoxide (DMSO), and the working concentration for treating K562 cells and zebrafish embryos is 20 µmol / L and 5 µmol / L, respectively.

[0020] The present invention is further described below through specific embodiments.Embodiment 1:

[0021] In K562 cells, Triac activated the expression of zeta-globin gene (HBZ) according to the following process: K562 cells were treated with hemin or hemin plus Triac for 72 hours, respectively, centrifugation was performed at 2000 rpm for 5 minutes to collect cells, a TRIzol reagent (Invitrogen) was used to extract total RNA, then a reverse transcription kit (ReverTra Ace, TOYOBO) was used to synthesize cDNA, and finally, a SYBR Green Realtime PCR Master Mix (TOYOBO) reagent was used to perform quantitative PCR.

[0022] A quantitative PCR reaction system was as follows: 2xSYBR Green PCR Master Mix5 ulF-Primer (10 pmol / L)0.6 ulR-Primer (10 µmol / L)0.6 ulcDNA1ulddH2O2.8 ulTotal volume10ul

[0023] Conditions for a quantitative PCR reaction were as follows: Hot start: 95°C, 10 minutes; Denaturation: 95°C, 10 seconds; and

[0024] Annealing / stretching: 60°C, 30 seconds.

[0025] 40 cycles.

[0026] Dissolution curve analysis.

[0027] As shown in Fig. 1, qPCR result shows that the expression of zeta-globin gene (HBZ) is up-regulated by 50.9 folds in Triac-treated K562 cells.

[0028] In fact, the sequence of human zeta-globin gene (HBZ) (NM_005332.3) (SEQ ID NO.1) is as follows:

[0029] Realtime PCR primers are as follows: Human-β-actin-FCCAACCGCGAGAAGATGA (SEQ ID NO.2)Human-β-actin-RCCAGAGGCGTACAGGGATAG (SEQ ID NO.3)Human-HBA1 / 2-FAAGGTCGGCGCGCACGC (SEQ ID NO.4)Human-HBA1 / 2-RCTCAGGTCGAAGTGCGGG (SEQ ID NO.5)Human-HBZ-FGGACCATCATTGTGTCCATGT (SEQ ID NO.6)Human-HBZ-RGGGAAGTAGGTCTTGGTCTGC (SEQ ID NO.7)Human-HBE1-FTGCATGTGGATCCTGAGAAC (SEQ ID NO.8)Human-HBE1-RCGACAGCAGACACCAGCTT (SEQ ID NO.9)Human-HBG1 / 2-FAGCACCTGGATGATCTCAAG (SEQ ID NO.10)Human-HBG1 / 2-RAAACGGTCACCAGCACATTT (SEQ ID NO.11)Human-HBD-FGATGCAGTTGGTGGTGAGG (SEQ ID NO.12)Human-HBD-RGGGTTGCCCATAACAGCAT (SEQ ID NO.13)Human-HBB-FGCACGTGGATCCTGAGAACT (SEQ ID NO.14)Human-HBB-RCACTGGTGGGGTGAATTCTT (SEQ ID NO.15)Embodiment 2:

[0030] During the development of zebrafish embryos, Triac, T3 and T4 were incubated with the zebrafish embryos at 96 hours post fertilization. After treatment with Triac, T3 and T4 for 24 hours, respectively, zebrafish embryos were fixed by 4% paraformaldehyde. The expression of zeta-globin gene (hbae5) was detected by Whole-mount mRNA in situ hybridization (WISH).

[0031] As shown in Fig. 2, Triac, T3 and T4 induce the expression of zeta-globin gene (hbae5) in zebrafish embryos.Embodiment 3:

[0032] During the development of zebrafish embryos, Triac, T3 and T4 were incubated with the zebrafish embryos at 96 hours post fertilization. After treatment with Triac, T3 and T4 for 24 hours, respectively, zebrafish embryos were collected. TRlzol reagent (Invitrogen) was used to extract total RNA, then a reverse transcription kit (ReverTra Ace, TOYOBO) was used to synthesize cDNA, and finally, a SYBRGreen Realtime PCR Master Mix (TOYOBO) reagent was used to perform quantitative PCR.

[0033] A quantitative PCR reaction system was as follows: 2xSYBR Green PCR Master Mix5 ulF-Primer (10 pmol / L)0.6ulR-Primer (10 µmol / L)0.6ulcDNA1 ulddH2O2.8 ulTotal volume10 ul

[0034] Conditions for a quantitative PCR reaction were as follows: Hot start: 95°C, 10 minutes; Denaturation: 95°C, 10 seconds; and Annealing / stretching: 60°C, 30 seconds.

[0035] 40 cycles.

[0036] Dissolution curve analysis.

[0037] As shown in Fig. 3, qPCR result shows that the expression of zeta-globin gene (hbae5) is up-regulated by 76-folds, 31-folds and 41-folds in Triac, T3 and T4-treated zebrafish embryos, respectively.

[0038] In fact, the sequence of zebrafish zeta-globin gene (hbae5) (NM_001326701.1) (SEQ ID NO.16) is as follows:

[0039] The Realtime PCR primers are as follows: Zebrafish-β-actin-FTGCTGTTTTCCCCTCCATTG (SEQ ID NO.17)Zebrafish-β-actin-RTTCTGTCCCATGCCAACCA (SEQ ID NO.18)Zebrafish-hbae1-FCTGAGGCTGTCAGCAAAATCG (SEQ ID NO.19)Zebrafish-hbae1-RGAACAAAGTGGCCAGAACCAC (SEQ ID NO.20)Zebrafish-hbae3-FGCTGATGGATGACCTGAAGGG (SEQ ID NO.21)Zebrafish-hbae3-RCTCAGGAGTGAAGTCGTCTGG (SEQ ID NO.22)Zebrafish-hbae5-FTGCTGAACCTCAGTGAATTGC (SEQ ID NO.23)Zebrafish-hbae5-RGGAACTTGTCGATGGCCAGAT (SEQ ID NO.24)Zebrafish-hbbe1-FTCCACGTAGATCCCGACAAC (SEQ ID NO.25)Zebrafish-hbbe1-RTACTGTCTTCCCAGAGCGGA (SEQ ID NO.26)Zebrafish-hbbe2-FGGACTGGACAGAGCCATGAAG (SEQ ID NO.27)Zebrafish-hbbe2-RGAGGCAATCACGATTGTCAGG (SEQ ID NO.28)Zebrafish-hbbe3-FTTGTGTGGACAGCTGAGGAG (SEQ ID NO.29)Zebrafish-hbbe3-RACGGATAGACGACCAAGCAT (SEQ ID NO.30)

[0040] The above description of the embodiments is intended to facilitate the understanding and use of the present invention by those of ordinary skill in the art.

Claims

1. A thyroid hormone analogue for use in a method for treating alpha-thalassemia, wherein that thyroid hormone analogue is Triac (i.e. 3,3',5-triiodothyroacetic acid).

2. A thyroid hormone analogue for use according to claim 1, wherein Triac up-regulates the expression of zeta-globin gene.