Application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases

Abstract

This invention discloses the application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases. This invention is based on the inventors' research findings that FGF-7 can induce the production of platelet-activating factor (PAF). The inventors discovered that PAF production induces an increase in the level of pro-inflammatory factors, subsequently triggering an inflammatory response. By using a molecule that inhibits the binding of FGF-7 to FGFR2b as a competitive antagonist of FGF7, binding to the FGF7-specific receptor FGFR2b, and blocking the activation of FGFR2b to phosphorylated FGFR2b, excessive inflammatory responses can be effectively inhibited, thereby treating ARDS symptoms and improving pulmonary fibrosis.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical biology, and specifically relates to the application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases. Background Technology

[0002] Acute respiratory distress syndrome (ARDS) is a clinical syndrome characterized by refractory hypoxemia caused by intrapulmonary and / or extrapulmonary causes, and is of great concern due to its high mortality rate. Its pathogenesis involves an uncontrolled patient-mediated autoimmune defense response, leading to inflammation, endothelial damage, enhanced coagulation, reduced fibrinolysis, and fibrosis. It is a clinical syndrome caused by various pathogens. In 1994, the American-European consensus conference committee recommended a definition of ARDS; the criteria included: (1) acute onset, (2) bilateral infiltrates on chest X-ray, (3) pulmonary artery wedge pressure ≤18 mm Hg or lack of clinical evidence of left atrial hypertension, and (4) Pao2 / Fio2 ratio ≤300 (defined as ALI) or Pao2 / Fio2 ratio ≤200 (defined as a more severe form of ALI) (Cepkova and Matthay, J. Intensive Care Med., 21:119-143, 2006). Diffuse alveolar damage is characteristic of ARDS. The disease has three overlapping phases: the exudative phase (the first 4-7 days), the proliferative phase (≥7-14 or 21 days), and the fibrotic phase (≥14 or 21 days) (MacLaren and Stringge, Pharmacotherapy, 27:860-873, 2007).

[0003] Significant neutrophil aggregation is observed in the acute phase. Neutrophils are predominant in pulmonary edema fluid and bronchoalveolar lavage fluid obtained from infected individuals. Alveolar macrophages secrete cytokines such as interleukins IL-1, IL-6, IL-10, IL-8, and tumor necrosis factor (TNF)-α, which stimulate neutrophil chemotaxis and activate neutrophils. Neutrophils then release oxidants, proteases (including neutrophil elastase), leukotrienes, and other pro-inflammatory cytokines (Ware and Mattray, New England J. Med. 342: 1334-1349). These mediators interact in complex ways to damage and inflame the alveolar-capillary interface, leading to a range of inflammatory responses and other symptoms.

[0004] Current treatment options for ARDS primarily involve immunosuppression (glucocorticoids) and supportive care (oxygenation) to alleviate and treat the condition. Glucocorticoids can prevent an overreaction of the immune system from causing further damage to the body, but they also have significant side effects, including, but not limited to, worsening infections, osteoporosis, and cardiovascular and digestive system complications. On the other hand, supportive care only maintains the patient's life and cannot treat the disease, thus having a very limited effect on improving the patient's survival rate.

[0005] Because the causes of the disease's occurrence and development are not fully understood, a targeted treatment for ARDS has not been developed, making the development of innovative therapeutic drugs an urgent priority. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and to provide the application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases.

[0007] The objective of this invention is achieved through the following technical solution: the application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases is based on the research results obtained by the inventors of this invention from the discovery that FGF-7 can induce the production of platelet activating factor PAF.

[0008] The PAF-mediated diseases include acute respiratory distress syndrome (ARDS) and acute inflammatory diseases such as pulmonary edema, pulmonary fibrosis, cardiovascular diseases such as arteriosclerosis, various PAF-related tumors, PAF-mediated tumor metastasis and recurrence caused by radiotherapy and chemotherapy, and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD).

[0009] The acute respiratory distress syndrome is preferably caused by bacterial infection and / or viral infection, including COVID-19, resulting in lung injury, pulmonary edema, and acute respiratory distress syndrome.

[0010] The virus is preferably a novel coronavirus; more preferably SARS-CoV, MERS-CoV, or 2019-nCoV.

[0011] The pulmonary fibrosis mentioned refers to idiopathic pulmonary fibrosis and pulmonary fibrosis caused by inflammation.

[0012] The FGFR2b inhibitory molecules include molecules that inhibit FGF-7 expression, molecules that inhibit FGFR2b activation to phosphorylated FGFR2b, and molecules that competitively inhibit the binding of FGF-7 to FGFR2b.

[0013] The molecules mentioned include, but are not limited to, siRNA, oligopeptides, and polypeptides.

[0014] The molecule that competitively inhibits the binding of FGF-7 to FGFR2b is preferably selected from the short peptides described in the national invention patent application with application number 2019102390870 and invention title "Short peptides, drugs and their applications for treating hair loss"; preferably, short peptides obtained by adding, deleting or mutating 0 to 2 amino acids at both ends, respectively, with EWVRTD, ELSGRA, QDVDS or VFSTTGV as the center; most preferably, EWVRTD, WVRTD, RHEWSRTD, ELSGRA, HTVELSGRAK, QDVDS, VFSTTGV, FGSVFSTTGV.

[0015] The molecule that inhibits FGFR2b activation to phosphorylated FGFR2b is preferably selected from the short peptide described in the national invention patent application number 201310714120.3 entitled "Gene sequence, polypeptide and application of extracellular segment of FGFR2b".

[0016] The present invention has the following advantages and effects compared with the prior art:

[0017] (1) The inventors of this invention first discovered that FGF7 can induce the production of platelet activating factor PAF.

[0018] (2) The inventors of this invention also discovered that PAF production can induce an increase in the level of pro-inflammatory factors, thereby triggering an inflammatory response. By using a molecule that inhibits the binding of FGF-7 to FGFR2 as a competitive antagonist of FGF7, it can bind to the FGF7 specific receptor FGFR2b and block the activation of FGFR2b to phosphorylated FGFR2b, which can effectively inhibit excessive inflammatory response and thus treat ARDS symptoms, and is also beneficial to improve pulmonary fibrosis.

[0019] (3) The growth factor antagonist PI9 (EWVRTD) used in this invention is a short peptide of 6 amino acids. It exerts its effect by preventing FGF7 from binding to its membrane receptor outside the cell, and has the characteristics of not needing to enter the cell and having a short half-life. At the same time, FGF7 has a unique binding receptor FGFR2b, so the target is clear, the pharmacological effect is very specific, and its toxic side effects are easy to evaluate. Therefore, this invention has broad application prospects in the preparation of ARDS drugs. Attached Figure Description

[0020] Figure 1 This is a graph showing the results of detecting and analyzing differential lipid PAFs between groups using lipidomics. Each column represents group A, group B, group C, and group D from left to right. Group A is the blank group, group B is the PI9 group, group C is the FGF7 group, and group D is the FGF7+PI9 group.

[0021] Figure 2 The figure shows the relative expression levels of IL-6 and IL-8 induced in sebaceous gland cells by PAF.

[0022] Figure 3 The figure shows the results of cytokine detection in an LPS-induced ARDS mouse model.

[0023] Figure 4 Photograph of lung tissue in a bleomycin-induced pulmonary fibrosis model of SD rats. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0025] Unless otherwise specified, the experimental techniques and methods used in the following examples are all conventional molecular biology techniques and methods, and researchers in the field can operate them to achieve the results. Unless otherwise specified, the materials and reagents used are commercially available.

[0026] The PBS used in this invention is 0.1 mol / L PBS with a pH of 7.4, and its composition is as follows: NaCl 16.00 g, KCl 0.40 g, KH2PO4 0.40 g, Na2HPO4·12H2O 5.80 g, diluted to 1 L with water.

[0027] Example 1

[0028] This embodiment 1 provides a short peptide and its pharmaceutical formulation, obtained by truncending 5-12 amino acids from the extracellular segment of FGFR (SEQ NO ID. 52) and performing 0-2 point mutations. The 5-12 amino acids truncated from the FGFR extracellular segment are spatially adjacent amino acids selected based on the three-dimensional structure of the FGFR extracellular segment. Specifically, the designed amino acids are centered at EWVRTD (PI9, SEQ NO ID. 9), ELSGRA (PI15, SEQ NO ID. 15), QDVDS (PI29, SEQ NO ID. 29), and VFSTTGV (PI47, SEQ NO ID. 47), with amino acid sequences added or deleted at both ends. The short peptide is named PI1-PI51.

[0029] The extracellular amino acid sequence of FGFR (from the amino terminus to the carboxyl terminus) is as follows (SEQ NO ID. 52):

[0030] APYWTNTEKMEKRLHAVPAANTVKFRCPAGGNPMPTMRWLKNGKEFKQEHRIGGYKVRNQHWSLIMESVVPSDKGNYTCVVENEYGSINHTYHLDVVERSPHRPILQAGLPANASTVVGGDVE FVCKVYSDAQPHIQWIKHVEKNGSKYGPDGLPYLKVLKHSGINSSNAEVLALFNVTEADAGEYICKVSNYIGQANQSAWLTVLPKQQAPGREKEITASPDYLEIAIYCIGVFLIACMVVTVIL.

[0031] The names, amino acid sequences, and sequence numbers of the short peptides are shown in Table 1.

[0032] Table 1

[0033]

[0034]

[0035] Short peptides require the addition of certain excipients and are stored in lyophilized powder form. Specifically, a short peptide solution of a certain concentration is prepared, for example, the concentration of short peptides in the solution can be 10–1000 μg / ml, preferably 100 μg / ml. 3% (m / v) sucrose, 1% (m / v) lactose, and 6% (m / v) sorbitol are added as excipients to the prepared short peptide solution. The solution is then stored at 4°C for 4–5 hours to allow the protective agents to fully dissolve and distribute evenly in the short peptide solution. Finally, the solution is pre-frozen at -20°C for 12–14 hours.

[0036] Example 2

[0037] Example 2 of this study found through lipidomics that FGF7 regulates the expression of Platlet Activating Factor (PAF).

[0038] 1.1 Preparation of Processed Samples

[0039] SZ95 human sebaceous gland cells were cultured. When the cells reached 70% confluence, they were digested with trypsin for 5 minutes, the trypsin was discarded, and SEB-1 complete medium (SEB-1 sebaceous gland cell medium + 10% fetal bovine serum, Zenbio, USA) was added to stop the digestion. The cells were then pipetted, mixed, and a cell suspension was formed. The cells were counted and grouped as shown in the table below, with 3 replicates per group. Primary sebaceous gland cells were seeded into 10cm culture dishes, with 3.7 × 10⁶ cells added to each well. 5Cells were cultured in 10 mL of SEB-1 complete medium, and the cells were adherent. The medium was changed every 48 hours. When the cells reached 70% confluence, serum-free medium (i.e., SEB-1 medium) was added, and the cells were starved for 12 hours. The medium was then discarded. Cells were treated as shown in Table 2: Group A had no drug added; Group B had 4 μg / mL PI9 (medium medium as solvent); Group C had 10 ng / mL FGF-7 (FGF-7 purchased from R&D Company, USA; medium medium as solvent); and Group D had 4 μg / mL PI9 + 10 ng / mL FGF7 (medium medium as solvent). 10 mL of drug-containing medium was added to each well, and the cells were cultured for 48 hours. The medium was then discarded, and the cells were collected by trypsin digestion for further processing.

[0040] The 12 cell samples were divided into three groups, as shown in the table below. LC-MS detection was performed using both positive and negative ion modes. Inter-group comparisons were conducted based on the detection results, and this report provides data from three comparisons.

[0041] Table 2 Grouping of 12 cell samples

[0042]

[0043] 1.2 Reagents and Consumables

[0044] Table 3 Reagents used in LC-MS experiments

[0045] Acetonitrile Thermo Fisher Methanol Thermo Fisher Formic acid Sigma Ammonium formate CNW Ultrapure water Millipore Chloroform Merck (Darmstadt, Germany)

[0046] 1.3 Experimental Methods

[0047] 1.3.1 Sample Preprocessing

[0048] 1. Add 800 μL of methanol, sonicate for 30 min, centrifuge, collect the supernatant, and dry with N2;

[0049] 2. Add 1.5 mL of dichloromethane / methanol (2:1, V / V) solution and 500 μL of water, vortex for 1 min, and centrifuge (3000 rpm, 15 min) after standing.

[0050] 3. Transfer the lower organic phase to a new glass tube;

[0051] 4. Dry the sample in a high-speed vacuum centrifuge, redissolve it with isopropanol / methanol (1:1, V / V), transfer it to a sample vial, and store it at -20℃ for later use.

[0052] 1.3.2 LC-MS Analysis

[0053] 1. Instrument analysis platform: LC-MS (Thermo, Ultimate 3000LC, Orbitrap Elite)

[0054] 2. Chromatographic column: C18 column (Kinetex C18 (100×2.1mm, 1.9μm))

[0055] 3. The chromatographic separation conditions were: column temperature 45℃; flow rate 0.4 mL / min;

[0056] Mobile phase composition A: acetonitrile:water (60:40, V / V), solution containing 10 mmol / L ammonium formate; B: acetonitrile:isopropanol (10:90, V / V), solution containing 10 mmol / L ammonium formate and 0.1% formic acid;

[0057] The injection volume was 4 μL, and the autosampler temperature was 4 °C.

[0058] 4. The gradient elution procedure for the mobile phase is shown in Table 4.

[0059] Table 4 Mobile Phase Elution Procedure

[0060]

[0061] 1.3.3 Data Analysis

[0062] The LC / MS detection data were extracted and preprocessed using Lipid Search software (Thermo Scientific), and normalized and edited in Excel 2010. The resulting data matrix was then imported into SIMCA-P 13.0 (Umetrics AB, Umea, Sweden) software for multivariate statistical analysis.

[0063] 1.3.4 Results Analysis

[0064] Differentially expressed lipids (PAFs) exist in various forms. By testing different forms of PAFs, the relative content of differentially expressed lipids (PAFs) is as follows: Figure 1 As shown, FGF-7 can induce PAF expression, and the combined use of PI9 and FGF-7 can inhibit FGF-7-induced PAF expression. In FGF7-regulated lipidomics studies, PAF is one type of differentially expressed lipid, and as a strong pro-inflammatory mediator, it is associated with inflammatory responses.

[0065] Example 3

[0066] SZ95 human sebaceous gland cells were induced with 20 μM PAF (Shanghai Yubo Biotechnology Co., Ltd.), and the effect of PAF on the expression of pro-inflammatory cytokines at different time points was detected by ELISA. The detection steps are as follows:

[0067] ① Sample collection: Transfer the cell culture medium to EP tubes, centrifuge at 4℃ and 12000rpm for 5 minutes in a pre-cooled refrigerated centrifuge, collect the supernatant, aliquot it into EP tubes, 400μL per EP tube, and store in a -20℃ freezer. Take it out and let it thaw at room temperature before use.

[0068] ②According to the instructions of the IL-6 ELISA and IL-8 ELISA kits from Beijing Sizhengbai Biotechnology Co., Ltd., bring the kits and experimental samples stored at 4℃ to room temperature for 30 minutes to equilibrate to room temperature;

[0069] ③ Add the sample to be tested into the corresponding enzyme-labeled wells, 100 μL per well, seal the reaction wells with sealing tape, and incubate in a 37℃ incubator for 90 min;

[0070] ④ Wash the plate 4 times: Remove the microplate, discard the sample, add 350 μL of washing buffer, let stand for 30 seconds, discard the washing buffer, repeat the washing 4 times, and pat dry on absorbent paper.

[0071] ⑤ Add 100 μL of biotinylated antibody working solution per well, seal the reaction wells with sealing paper, and incubate at 37°C for 60 min; repeat step ④ to wash the plate;

[0072] ⑥ Add 100 μL of enzyme conjugate working solution to each well, seal the wells with sealing paper, and incubate at 37°C for 30 min. Repeat step ④.

[0073] ⑦ Add 100 μL of colorimetric solution per well, incubate at 37°C in the dark for 15 min, remove the microplate, add 100 μL of stop solution per well, gently shake to mix, and measure the OD450 value within 5 min.

[0074] Results analysis showed that the expression of pro-inflammatory cytokines was as follows: Figure 2 As shown, PAF-induced expression of IL-6 and IL-8 in sebaceous gland cells increased over time, reaching its maximum after 16 hours of induction. Compared with the control group, IL-6 increased by 4.1 times and IL-8 increased by 3.4 times. The expression of both decreased after 24 hours and 48 hours of induction.

[0075] Example 4

[0076] By establishing an LPS-induced acute respiratory distress syndrome (ARDS) mouse model, we conducted cell counts and cytokine assays in the lung lavage fluid of mice.

[0077] 4.1 BALB / c mice from Shanghai Lingchang Experimental Animal Co., Ltd. were used for the experiment. The grouping information is shown in Table 5.

[0078] Table 5 Grouping and Dosing Regimens

[0079]

[0080] 4.1.1 LPS solution preparation: LPS was dissolved in PBS to make the final concentration of LPS solution 1.0 mg / mL.

[0081] 4.1.2 Dexamethasone was first administered orally 0.5 hours later.

[0082] 4.1.3 At 0 hours, animals in groups G2-G5 and at 6 hours, animals in groups G6-G7 were induced with acute lung injury using LPS. 50 μL of the modeling agent LPS was administered intratracheally using a special nebulizer. Group G1 animals received the same volume of LPS as solvent treatment. Prior to tracheal injection, animals were anesthetized with 2-5% isoflurane inhalation.

[0083] 4.1.4 Administer the medication according to Table 5.

[0084] 4.1.5 Twenty-four hours after LPS modeling, all animals were anesthetized by intraperitoneal injection of 25 mg / kg of sulfadiazine, intubated, and their lungs were lavaged for the first time with 0.5 mL of PBS (containing 0.04 M EDTA-K2). A second 0.5 mL of PBS (containing 0.04 M EDTA-K2) was then used for the second lavage. Both lavage fluids (bronchoalveolar lavage fluid, BALF) were placed on ice.

[0085] Centrifuge and resuspend in PBS to obtain cells. Dilute the cell suspension to a concentration of approximately 10. 7 Cells / mL: Transfer 100 μL of cell culture to a blood cell separator and centrifuge at 800 rpm for 5 minutes. Air-dry the slide, fix it appropriately in methanol solution, and then stain with Wright-Giemsa staining solution to distinguish eosinophils, neutrophils, macrophages, and lymphocytes. Count the cells under a light microscope.

[0086] 4.1.6 All supernatants were stored in an ultra-low temperature freezer and transferred to an in vitro laboratory for total protein determination and detection of TNF-α, IL-1β, IL-6, FGF7 and PAF, all in duplicate.

[0087] The experimental mice were divided into seven groups, G1-G7, where G1 was the normal group, G2 was the model-solvent group, G3 was the model-dexamethasone group, G4 was the model-0-hour administration group (100 μg / mouse), G5 was the model-0-hour administration group (150 μg / mouse), G6 was the model-6-hour administration group (100 μg / mouse), and G7 was the model-6-hour administration group (150 μg / mouse). The results of cytokine detection in the bronchoalveolar lavage fluid are as follows: Figure 3 As shown in the results, the levels of TNF-α, IL-6, IL-1β, FGF7, and BALF protein in the model group-solvent group were significantly higher than those in the normal group. The model-dexamethasone group significantly inhibited TNF-α, IL-6, IL-1β, and FGF7 in the BALF supernatant. In the model-drug group, the 100 μg / mouse dose was administered twice, at 6 and 12 hours after modeling, and significantly inhibited PAF in the BALF supernatant 24 hours after modeling. This indicates that the degree of inhibition of cytokine expression by the FGF-7 short peptide inhibitor is time-dependent.

[0088] The results of cell counting in the pulmonary lavage fluid are shown in Table 6. The average number of neutrophils (neu) in the drug treatment group was greater than that in the dexamethasone group, indicating that the inhibitory effect of PI9 on neutrophils was weaker than that of dexamethasone. However, the excessive inhibition of inflammatory response by dexamethasone may affect the body's ability to fight against foreign pathogens.

[0089] Table 6 Cell counts in lung lavage fluid

[0090]

[0091] Example 5

[0092] The effect of the short peptide PI1-PI51 (concentration of 100 μg / ml) described in Example 1 on PAF expression in the bronchoalveolar lavage fluid of ARDS was studied by establishing an LPS-induced acute respiratory distress syndrome (ARDS) mouse model (see Example 4) (procedure as in Example 4).

[0093] Table 7

[0094]

[0095]

[0096] Note: The relative value, i.e., the inhibition rate, is based on the normal control group.

[0097] As shown in Table 7, compared with the ineffective negative control group, the short peptides with high similarity to EWVRTD (PI9, SEQ NO ID.9), ELSGRA (PI15, SEQ NO ID.15), QDVDS (PI29, SEQ NO ID.29), and VFSTTGV (PI47, SEQ NO ID.47) had a better inhibitory effect on PAF expression.

[0098] Example 6

[0099] This study investigated the inhibitory effect of PI9 on pulmonary fibrosis using a bleomycin-induced pulmonary fibrosis rat model (purchased from the Guangdong Provincial Animal Experiment Center).

[0100] I. Establishment of a bleomycin-induced pulmonary fibrosis model in SD rats

[0101] All rats were fasted and deprived of water for 12 hours before surgery, weighed, and anesthetized with 10% chloral hydrate intraperitoneally at a dose of 3 ml / kg. The neck was prepared, and the rats' four legs, head, and incisors were fixed to the operating table. The area was disinfected with povidone-iodine and then wiped with alcohol. A vertical incision of approximately 0.5 cm was made in the upper part of the bronchus using ophthalmic scissors. The muscles were dissected layer by layer with ophthalmic forceps and straight forceps to expose the trachea and confirm the location of the thyroid cartilage. One end of the rat's head was raised to an angle of more than 30° with the table, and then, under direct vision, a syringe needle was inserted into the cricoid cartilage of the trachea. A feeling of emptiness was felt upon insertion, and bleomycin solution was slowly injected. The rat was held upright on a board, and rotated alternately left and right for 2 minutes to ensure even distribution of the drug in both lungs. After suturing the muscles and skin layers, the area was disinfected with povidone-iodine, and a penicillin solution at a dose of 80,000 IU / rat was injected intraperitoneally to prevent postoperative infection.

[0102] II. Experimental grouping and dosing regimen

[0103] Grouping:

[0104] Normal control group: 250 μl of normal saline was injected into the trachea during modeling;

[0105] BLM group: 5 mg / kg bleomycin solution was injected into the trachea during modeling;

[0106] BLM+PI9 group: 5 mg / kg bleomycin solution was injected into the trachea during modeling, and the drug was administered 7 days after modeling.

[0107] Administration method:

[0108] Dosing began on day 7 of modeling and continued for 14 days.

[0109] Normal control group: 400 μl of normal saline was injected intraperitoneally;

[0110] BLM group: 400 μl of normal saline was injected intraperitoneally;

[0111] BLM+PI9 administration group: P-8 polypeptide was injected intraperitoneally, 100 μg / animal / day.

[0112] Results of various rat lung tissues, such as Figure 4 As shown, in the observation of the bleomycin-induced pulmonary fibrosis model in SD rats, the lung tissue of the treatment group showed a more intact lung structure and significantly reduced collagen and FGF-2 compared with the model group. The results indicate that PI9 has a significant inhibitory effect on pulmonary fibrosis.

[0113] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention. sequence list <110> Jinan University <120> Application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases <160> 52 <170> SIPOSequenceListing 1.0 <210> 1 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> PI1 <400> 1 Ala Arg His Glu Trp Val Arg Thr Asp Gly 1 5 10 <210> 2 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI2 <400> 2 His Glu Trp Ser Arg Thr 1 5 <210> 3 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI3 <400> 3 Arg His Glu Trp Ser Arg Thr 1 5 <210> 4 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI4 <400> 4 Arg His Glu Trp Val Arg Thr Asp Gly 1 5 <210> 5 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> PI5 <400> 5 Ala Arg His Glu Trp Val Arg Thr Asp Gly 1 5 10 <210> 6 <211> 11 <212> PRT <213> Artificial Sequence <220> <223> PI6 <400> 6 Ala Arg His Glu Trp Val Thr Thr Asp Gly Gly 1 5 10 <210> 7 <211> 12 <212> PRT <213> Artificial Sequence <220> <223> PI7 <400> 7 Ala Arg His Glu Trp Val Arg Thr Asp Gly Gly Ser 1 5 10 <210> 8 <211> 5 <212> PRT <213> Artificial Sequence <220> <223> PI8 <400> 8 Trp Val Arg Thr Asp 1 5 <210> 9 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI9 <400> 9 Glu Trp Val Arg Thr Asp 1 5 <210> 10 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI10 <400> 10 His Glu Trp Ser Arg Thr 1 5 <210> 11 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI11 <400> 11 Arg His Glu Trp Ser Arg Thr Asp Gly 1 5 <210> 12 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI12 <400> 12 Arg His Glu Trp Ser Arg Thr Asp 1 5 <210> 13 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI13 <400> 13 Glu Leu Ser Gly Arg Ala Lys 1 5 <210> 14 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI14 <400> 14 Thr Lys Glu Leu Ser Gly Arg Ala 1 5 <210> 15 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI15 <400> 15 Glu Leu Ser Gly Arg Ala 1 5 <210> 16 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> PI16 <400> 16 His Thr Val Glu Leu Ser Gly Arg Ala Lys 1 5 10 <210> 17 <211> 11 <212> PRT <213> Artificial Sequence <220> <223> PI17 <400> 17 His Thr Lys Glu Leu Ser Gly Arg Ala Lys Leu 1 5 10 <210> 18 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI18 <400> 18 Thr Val Glu Leu Ser Gly Arg Ala Lys 1 5 <210> 19 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI19 <400> 19 His Thr Lys Glu Leu Ser Gly Arg Ala 1 5 <210> 20 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI20 <400> 20 Val Glu Leu Ser Gly Arg Ala Lys 1 5 <210> twenty one <211> 5 <212> PRT <213> Artificial Sequence <220> <223> PI21 <400> twenty one Glu Leu Ser Gly Arg 1 5 <210> twenty two <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI22 <400> twenty two Lys Glu Leu Ser Gly Arg Ala 1 5 <210> twenty three <211> 12 <212> PRT <213> Artificial Sequence <220> <223> PI23 <400> twenty three His Thr Lys Glu Leu Ser Gly Arg Ala Lys Leu Ile 1 5 10 <210> twenty four <211> 5 <212> PRT <213> Artificial Sequence <220> <223> PI24 <400> twenty four Glu His Ser Gly Arg 1 5 <210> 25 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI25 <400> 25 Lys Glu His Ser Gly Arg 1 5 <210> 26 <211> 5 <212> PRT <213> Artificial Sequence <220> <223> PI26 <400> 26 Leu Ser Gly Arg Ala 1 5 <210> 27 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI27 <400> 27 Pro Leu Arg Gln Asp Val Asp Ser 1 5 <210> 28 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI28 <400> 28 Pro Leu Arg Gln Asp Val Asp 1 5 <210> 29 <211> 5 <212> PRT <213> Artificial Sequence <220> <223> PI29 <400> 29 Gln Asp Val Asp Ser 1 5 <210> 30 <211> 12 <212> PRT <213> Artificial Sequence <220> <223> PI30 <400> 30 Pro Leu Arg Gln Asp Val Asp Ser Arg Ser Thr His 1 5 10 <210> 31 <211> 11 <212> PRT <213> Artificial Sequence <220> <223> PI31 <400> 31 Pro Leu Arg Gln His Val Asp Ser Arg Ser Thr 1 5 10 <210> 32 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI32 <400> 32 Arg Gln Asp Val Asp Ser Arg 1 5 <210> 33 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI33 <400> 33 Leu Gly Gln Asp Val Asp Ser 1 5 <210> 34 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI34 <400> 34 Pro Leu Arg Gln Asp Val 1 5 <210> 35 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI35 <400> 35 Arg Gln Asp Val Asp Ser 1 5 <210> 36 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI36 <400> 36 Leu Gly Gln Asp Val Asp 1 5 <210> 37 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> PI37 <400> 37 Pro Leu Arg Gln Asp Val Asp Ser Arg Ser 1 5 10 <210> 38 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI38 <400> 38 Leu Gly Gln Asp Val Asp Ser Arg 1 5 <210> 39 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI39 <400> 39 Pro Leu Arg Gln Asp Val Asp Ser Arg 1 5 <210> 40 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI40 <400> 40 Phe Gly Ser Val Phe Ser Thr Thr Gly 1 5 <210> 41 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> PI41 <400> 41 Gly Ser Val Phe Ser Thr Thr Gly Val 1 5 <210> 42 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI42 <400> 42 Ser Val Phe Ser Thr Thr Gly Val 1 5 <210> 43 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI43 <400> 43 Phe Gly Ser Val Phe Ser Thr 1 5 <210> 44 <211> 13 <212> PRT <213> Artificial Sequence <220> <223> PI44 <400> 44 Phe Gly Ser Val Phe Ser Thr Thr Gly Val Ile Ser Arg 1 5 10 <210> 45 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI45 <400> 45 Ser Val Phe Ser Thr Thr Gly 1 5 <210> 46 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> PI46 <400> 46 Val Phe Ser Thr Thr Ile 1 5 <210> 47 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> PI47 <400> 47 Val Phe Ser Thr Thr Gly Val 1 5 <210> 48 <211> 12 <212> PRT <213> Artificial Sequence <220> <223> PI48 <400> 48 Phe Gly Ser Val Phe Ser Thr Thr Gly Val Ile Ser 1 5 10 <210> 49 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> PI49 <400> 49 Phe Gly Ser Val Phe Ser Thr Thr 1 5 <210> 50 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> PI50 <400> 50 Phe Gly Ser Val Phe Ser Thr Thr Gly Val 1 5 10 <210> 51 <211> 11 <212> PRT <213> Artificial Sequence <220> <223> PI51 <400> 51 Phe Gly Ser Val Phe Ser Thr Cys Gly Val Ile 1 5 10 <211> 246 <212> PRT <213> Artificial Sequence <220> <223> FGFR extracellular amino acid sequence <400> 52 Ala Pro Tyr Trp Thr Asn Thr Glu Lys Met Glu Lys Arg Leu His Ala 1 5 10 15 Val Pro Ala Ala Asn Thr Val Lys Phe Arg Cys Pro Ala Gly Gly Asn 20 25 30 Pro Met Pro Thr Met Arg Trp Leu Lys Asn Gly Lys Glu Phe Lys Gln 35 40 45 Glu His Arg Ile Gly Gly Tyr Lys Val Arg Asn Gln His Trp Ser Leu 50 55 60 Ile Met Glu Ser Val Val Pro Ser Asp Lys Gly Asn Tyr Thr Cys Val 65 70 75 80 Val Glu Asn Glu Tyr Gly Ser Ile Asn His Thr Tyr His Leu Asp Val 85 90 95 Val Glu Arg Ser Pro His Arg Pro Ile Leu Gln Ala Gly Leu Pro Ala 100 105 110 Asn Ala Ser Thr Val Val Gly Gly Asp Val Glu Phe Val Cys Lys Val 115 120 125 Tyr Ser Asp Ala Gln Pro His Ile Gln Trp Ile Lys His Val Glu Lys 130 135 140 Asn Gly Ser Lys Tyr Gly Pro Asp Gly Leu Pro Tyr Leu Lys Val Leu 145 150 155 160 Lys His Ser Gly Ile Asn Ser Ser Asn Ala Glu Val Leu Ala Leu Phe 165 170 175 Asn Val Thr Glu Ala Asp Ala Gly Glu Tyr Ile Cys Lys Val Ser Asn 180 185 190 Tyr Ile Gly Gln Ala Asn Gln Ser Ala Trp Leu Thr Val Leu Pro Lys 195 200 205 Gln Gln Ala Pro Gly Arg Glu Lys Glu Ile Thr Ala Ser Pro Asp Tyr 210 215 220 Leu Glu Ile Ala Ile Tyr Cys Ile Gly Val Phe Leu Ile Ala Cys Met 225 230 235 240 Election Election Thr Election Ile Leu 245

Claims

1. The application of FGFR2b inhibitory molecules in the preparation of drugs for treating PAF-mediated diseases, characterized in that: The PAF-mediated diseases mentioned are acute respiratory distress syndrome, pulmonary edema, and pulmonary fibrosis. The FGFR2b inhibitory molecule is EWVRTD.

2. The use of the FGFR2b inhibitor molecule according to claim 1 in the preparation of drugs for treating PAF-mediated diseases, characterized in that: The acute respiratory distress syndrome mentioned refers to acute respiratory distress syndrome caused by viral or bacterial infections.

3. The use of the FGFR2b inhibitor molecule according to claim 2 in the preparation of drugs for treating PAF-mediated diseases, characterized in that: The virus in question is a coronavirus.

4. The use of the FGFR2b inhibitor molecule according to claim 3 in the preparation of drugs for treating PAF-mediated diseases, characterized in that: The coronaviruses mentioned are SARS-CoV, MERS-CoV, or 2019-nCoV.

5. The use of the FGFR2b inhibitor molecule according to claim 1 in the preparation of drugs for treating PAF-mediated diseases, characterized in that: The pulmonary fibrosis mentioned refers to idiopathic pulmonary fibrosis and pulmonary fibrosis caused by inflammation.

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