Application of IL-33 in preparation of medicine for treating and / or relieving brain injury after subarachnoid hemorrhage

Abstract

The invention provides application of IL-33 in preparation of a medicine for treating and / or relieving brain injury after subarachnoid hemorrhage, and belongs to the technical field of medicine. The invention clarifies a mechanism that IL-33 plays a role in neuroprotection in a rat subarachnoid hemorrhage model, verifies that exogenous IL-33 treatment can activate an ST2 receptor, further promotes M2-type polarization of microglial cells, plays a role in neuroprotection in the progress of subarachnoid hemorrhage, can improve prognosis after subarachnoid hemorrhage, and has a good application prospect in treatment of subarachnoid hemorrhage. The compound can be applied to preparation of drugs for treating and / or relieving brain injury after subarachnoid hemorrhage.

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical technology, and particularly relates to the application of IL-33 in the preparation of a drug for treating and / or alleviating brain injury after subarachnoid hemorrhage. Background Art

[0002] Subarachnoid hemorrhage (SAH) is a severe cerebrovascular disease with high disability and mortality rates. Different causes can lead to subarachnoid hemorrhage, such as ruptured cerebral aneurysms, arteriovenous malformations, moyamoya disease, and cerebral amyloid angiopathy. Although significant progress has been made in surgical and clinical treatments, the mortality rate of subarachnoid hemorrhage remains between 25% and 35%. Evidence shows that early brain injury is the main cause of poor prognosis after subarachnoid hemorrhage. It is believed that early brain injury occurring within 72 hours after subarachnoid hemorrhage may be a key factor in neurological deficits. However, there is still a lack of effective drug treatment strategies for early brain injury.

[0003] Microglia are the main immune cells in the central nervous system and play a key role in regulating brain homeostasis. To achieve these diverse functions, microglia must undergo extensive morphological and functional reprogramming to meet the needs of the brain. Among them, selective activation of the microglial M2 phenotype assists in tissue repair under various acute brain injury conditions. In addition, a large amount of evidence shows its important role in the early inflammatory response after subarachnoid hemorrhage. It has also been reported that M2 microglia can promote hematoma clearance, neuron survival, and reduce brain injury. Therefore, the underlying mechanisms of the inflammatory response are crucial for designing novel anti-inflammatory treatment methods for SAH patients.

[0004] IL-33 is a multifunctional cytokine and one of the new members of the interleukin-1 family, participating in various immune-mediated diseases, such as rheumatism, respiratory diseases, and cardiovascular diseases. In addition, IL-33 is also involved in regulating inflammatory and apoptotic pathways. However, the biological functions and underlying mechanisms of IL-33 in brain injury after SAH have not been studied. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide the application of IL-33 in the preparation of a drug for treating and / or alleviating brain injury after subarachnoid hemorrhage.

[0006] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides the application of IL-33 in the preparation of a drug for treating and / or alleviating brain injury after subarachnoid hemorrhage.

[0008] Preferably, the IL-33 alleviates the short-term motor dysfunction induced by subarachnoid hemorrhage.

[0009] Preferably, the IL-33 alleviates the cerebral edema induced by subarachnoid hemorrhage.

[0010] Preferably, the IL-33 alleviates the neuronal apoptosis induced by subarachnoid hemorrhage.

[0011] Preferably, the IL-33 activates the ST2 receptor and promotes the M2 polarization of microglia after subarachnoid hemorrhage.

[0012] Preferably, the IL-33 increases the number of branches, the number of terminals and the branch length of microglia after subarachnoid hemorrhage.

[0013] Preferably, the IL-33 improves the prognosis after subarachnoid hemorrhage.

[0014] Preferably, the active ingredient of the drug includes IL-33.

[0015] Preferably, the drug further includes a pharmaceutically acceptable carrier.

[0016] Preferably, the content of IL-33 in the drug is 60-100 wt%.

[0017] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0018] The present invention clarifies the mechanism by which IL-33 plays a neuroprotective role in the subarachnoid hemorrhage model, and this mechanism is mediated by activating the ST2 / AKT axis in microglia. The present invention shows through experiments that exogenous IL-33 treatment can activate the ST2 receptor, thereby promoting the M2 polarization of microglia, playing a neuroprotective role in the progression of subarachnoid hemorrhage, alleviating the cerebral edema induced by subarachnoid hemorrhage, alleviating the neuronal apoptosis induced by subarachnoid hemorrhage, increasing the number of branches, the number of terminals and the branch length of microglia after subarachnoid hemorrhage, alleviating the short-term motor dysfunction induced by subarachnoid hemorrhage, and reducing nervous system lesions through the IL-33 / ST2 signaling pathway, thereby effectively improving the prognosis after subarachnoid hemorrhage. Brief Description of the Drawings

[0019] Figure 1 : Flow chart of Experiment 1;

[0020] Figure 2 : Flow chart of Experiment 2;

[0021] Figure 3 : Protein localization and expression changes of IL-33 within 72 hours after subarachnoid hemorrhage;

[0022] Figure 4 : Changes in the localization and expression of ST2 protein within 72 hours after subarachnoid hemorrhage;

[0023] Figure 5 : Effects of IL-33 on the neurobehavioral outcomes caused by subarachnoid hemorrhage;

[0024] Figure 6 : Effects of IL-33 administration on neuronal apoptosis;

[0025] Figure 7 : Effects of IL-33 administration on microglia in the temporal basal cortex after subarachnoid hemorrhage;

[0026] Figure 8 : The neuroprotective functional mechanism of IL-33. Specific implementation manners

[0027] The present invention provides the use of IL-33 in the preparation of a drug for treating and / or alleviating brain injury after subarachnoid hemorrhage. IL-33 is a multifunctional cytokine and one of the latest members of the interleukin-1 family, participating in a variety of immune-mediated diseases and also involved in regulating inflammatory and apoptotic pathways. Its dominant receptor ST2 is a member of the interleukin-1 receptor family and is expressed on a variety of immune cells including microglia.

[0028] The present invention discovers that subarachnoid hemorrhage promotes the endogenous expression of IL-33 and its receptor ST2, and the expression of ST2 in microglia increases most significantly after subarachnoid hemorrhage. Experimental studies have confirmed that exogenous IL-33 treatment can activate the ST2 receptor, thereby promoting the M2 polarization of microglia. IL-33 can relieve subarachnoid hemorrhage-induced brain edema, relieve subarachnoid hemorrhage-induced neuronal apoptosis, increase the number of branches, the number of terminals and the branch length of microglia after subarachnoid hemorrhage, and play a neuroprotective role in the progression of subarachnoid hemorrhage. IL-33 can relieve subarachnoid hemorrhage-induced short-term motor function deficit and improve the short-term neurobehavioral score in a dose-dependent manner. And IL-33 alleviates nervous system lesions through the IL-33 / ST2 signaling pathway, thereby improving the prognosis after subarachnoid hemorrhage.

[0029] The active ingredient of the drug according to the present invention includes IL-33, that is, IL-33 can be used as the sole active ingredient, or IL-33 can be used in combination with other drugs. The content of IL-33 in the drug according to the present invention is 60-100 wt%, preferably 80-99 wt%. Preferably, the drug according to the present invention further includes a pharmaceutically acceptable carrier to ensure the convenience of the preparation of the prepared drug and clinical application. More preferably, the dosage form of the drug according to the present invention includes an injection. The dosage form of the drug according to the present invention is not limited thereto, and other achievable dosage forms are within the protection scope of the present invention.

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] All data are expressed as mean ± standard deviation (SD). All statistical analyses were performed using GraphPad PRISM 8.0 statistical software. One-way analysis of variance (ANOVA) was used to compare multiple groups, and unpaired t-tests were used to compare differences between two groups. Two-way analysis of variance was used for behavioral tests. Independent experiments were performed for each treatment. A P value less than 0.05 was considered statistically significant. A P value less than 0.01 was considered to have significant statistical significance.

[0032] In the following embodiments, unless otherwise specified, they are all conventional methods. The materials, reagents, etc. used in the following embodiments, unless otherwise specified, can all be obtained from commercial channels.

[0033] Example 1

[0034] 1. Experimental animals

[0035] 7-week-old male Sprague-Dawley (SD) rats, weighing about 250-300 g. The animals were housed in a standard animal room at a temperature of 25 ± 1 °C and a humidity of 50-60%, and had free access to food and water. The animals were regularly maintained with 12 hours of light and 12 hours of darkness. All SD rats were purchased from Shanghai Slac Laboratory Animal Co., Ltd. (Shanghai).

[0036] 2. Establishment of subarachnoid hemorrhage model

[0037] The endovascular puncture method was used to establish a rat model of subarachnoid hemorrhage as follows (refer to Xie, Z., et al., Exendin-4 attenuates neuronal death via GLP-1R / PI3K / Akt pathway in early brain injury after subarachnoid hemorrhage in rats. Neuropharmacology, 2018. 128: p. 142-151):

[0038] First, the rats were anesthetized with 10% chloral hydrate and placed in a suitable position. Next, the left external carotid artery was ligated and transected, and a sharp 4-0 nylon suture was inserted into the right internal carotid artery and advanced forward until resistance was felt. After advancing another 2-3 mm, a sense of falling through was felt, the suture was withdrawn, and the incision was sutured. The rats in the sham operation group were operated in the same way but without puncturing the blood vessel. After the operation, the animals were separated and closely observed for 1 hour and then returned to the cage for breeding.

[0039] To exclude the bias caused by individual differences, the rats were scored for subarachnoid hemorrhage. The basal part of the rat brain was photographed immediately after euthanasia and evaluated by two independent researchers. The total score (18 points) was calculated by adding up the scores of six different regions determined. Each region was divided into 0-3 points. Rats with a score ≤ 7 points were excluded from the experiment (refer to Sugawara, T., et al., A new grading system evaluating bleeding scale in filament perforation subarachnoid hemorrhage rat model. J Neurosci Methods, 2008. 167(2): p. 327-34).

[0040] 3. Experimental design

[0041] Experiment 1: 96 rats were randomly divided into 6 groups (n = 16 / group). Sham operation group, subarachnoid hemorrhage groups (3, 6, 12, 24, 72 hours after modeling). The expression location and content of related proteins in the temporal basal brain tissue of rats in each group were detected; meanwhile, Western blot experiments were performed to detect the expression of IL-33 and ST2; TUNEL staining was used to measure the apoptosis level of each group. The experimental procedure was as Figure 1 shown.

[0042] Experiment 2: 130 rats were randomly divided into 5 groups (n = 26 / group): sham operation group, subarachnoid hemorrhage group, subarachnoid hemorrhage group + IL-33 (30 μg / kg) group, subarachnoid hemorrhage group + IL-33 (60 μg / kg) group, and subarachnoid hemorrhage group + IL-33 (90 μg / kg) group. The temporal bottom brain tissues of rats in each group were taken as samples, and the polarization state of microglia was detected by immunofluorescence staining. TUNEL staining was used to detect neuronal apoptosis (n = 3 / group). Modified Garcia score and balance beam test score were used for short-term behavioral evaluation. The brain edema conditions of the left brain, right brain, cerebellum, and brainstem were used to detect early brain injury. The experimental procedure was as Figure 2 shown. The administration method was as follows: Immediately after subarachnoid hemorrhage surgery, IL-33 recombinant protein was administered at doses of 30 μg / kg body weight, 60 μg / kg body weight, and 90 μg / kg body weight of the animals. The corresponding doses of IL-33 were dissolved in PBS solution and then treated by tail vein injection. The IL-33 recombinant protein was from Wuhan Yunke Long Biotechnology Co., Ltd. (CAS: RPB980Ra01).

[0043] 4. Polyacrylamide Gel Electrophoresis and Transfer

[0044] The temporal bottom brain tissue samples were homogenized, then lysed in cell lysis buffer RIPA for 30 minutes, and then centrifuged at 12,000 g for 10 minutes at 4 °C to collect the supernatant. A BCA detection kit (Beyotime, Shanghai, China) was used to determine the protein content. On the prepared 10% sodium dodecyl sulfate (SDS)-polyacrylamide gel, protein samples (30 μg / lane) and molecular weight markers (4 μl / well; Thermo Fisher Scientific, Waltham, MA, USA) were loaded, and then separated and transferred to a PVDF membrane (Millipore Corporation, Billerica, USA) for electrophoresis. The membrane was incubated with 5% non-fat milk at room temperature for 1 hour, and then incubated with the target antibodies (IL-33, ab187060, 1:1000, Abcam; ST2, ab194113, 1:1000, Abcam) overnight at 4 °C. Then, the horseradish peroxidase (HRP)-conjugated secondary antibody (Santa Cruz Biotechnology, Santa Cruz, CA, USA) was incubated with the membrane at room temperature for 1 hour, and washed three times with PBST (PBS + 0.1% Tween 20). Finally, the gray value of the membrane was detected using an enhanced chemiluminescence (ECL) detection reagent (Clinx Scientific Instruments Co., Ltd.). ImageJ software (NIH, Bethesda, MA, USA) was used to analyze the gray changes of the protein bands.

[0045] 5. Modified Garcia Score

[0046] The modified Garcia score was used to evaluate neurological deficits in rats after subarachnoid hemorrhage. The evaluation content included spontaneous movement, symmetrical movement of the four limbs, and forepaw extension, scored from 0 to 3 points, and crawling, body proprioception, and tactile response, scored from 1 to 3 points. Two independent researchers recorded the scores of the experimental rats (refer to Guo, D., et al., MRI Characterization in the Acute Phase of Experimental Subarachnoid Hemorrhage. Transl Stroke Res, 2017. 8(3): p. 234 - 243).

[0047] 6. Balance Beam Test

[0048] The balance beam walking test score was used to evaluate the balance and coordinated movement ability of rats after subarachnoid hemorrhage. The total score was 4 points, and during the experiment, the scores were evaluated by two experimenters using a double - blind method. (Refer to Zhang, A., et al., CCL17 exerts neuroprotection through activation of CCR4 / mTORC2 axis in microglia after subarachnoid hemorrhage in rats. Stroke Vasc Neurol, 2022. 8(1)).

[0049] 7. Measurement of Brain Water Content

[0050] The wet - dry method was used to measure the brain water content. The specific experimental method was as follows: At specific time points after subarachnoid hemorrhage, rats were anesthetized with 5% isoflurane plus a mixed gas containing medical air (70%) and oxygen (30%). After the rats were anesthetized, they were quickly decapitated, and the brain was immediately removed from the skull. Subsequently, it was divided into four parts: the left and right cerebral hemispheres, the cerebellum, and the brainstem, and placed on an electronic analytical balance (weight recorded accurately to 0.01 mg) to measure the wet weight of each part of the brain tissue. During the process, care was taken to avoid touching the brain tissue with hands to interfere with the water content on the surface of the brain tissue. Subsequently, each brain tissue was placed in an electro - thermal constant - temperature forced - air drying oven (100 °C) and baked for 1 day (24 hours) until constant weight, and the second weighing (dry weight) was performed. The calculation formula for brain water content was: Brain tissue water content (%) = [(wet weight of brain tissue - dry weight of brain tissue) / (wet weight)] × 100%.

[0051] 8. Immunofluorescence Staining

[0052] After taking out the 8-μm sections stored in an -80°C refrigerator, place them in a wet box for rewarming at room temperature (15 minutes); wash them 3 times with 0.1 M PBS buffer solution for 5 minutes each time to wash away the covering embedding medium; use an immunohistochemistry pen to circle the staining area of the brain tissue to prevent liquid from flowing out and keep it moist during the staining process. Incubate with 0.3% Triton-100 at room temperature for 15 - 30 minutes to permeabilize the cells. Finally, wash with PBS buffer solution 3 times for 5 minutes each time; Blocking: Block the staining area with 5% donkey serum to avoid non-specific binding of antibodies, and place it at room temperature for 1 hour; Dropwise add the corresponding primary antibody at an appropriate concentration and incubate overnight at 4°C. The next day, place the wet box at room temperature for 30 minutes of rewarming, and wash with PBS buffer solution 3 times for 5 minutes each time. The corresponding primary antibodies and specific dilution ratios are as follows: IL-33, ab187060, 1:200, Abcam; ST2, ab194113, 1:200, Abcam; NEUN, ab104224, 1:200, Abcam; GFAP, ab302644, 1:200, Abcam; Iba-1, ab283319, 1:200, Abcam. Add donkey anti-rabbit IgG conjugated with FITC and donkey anti-mouse IgG conjugated with Texas Red (1:200) respectively; or donkey anti-rabbit IgG conjugated with FITC and donkey anti-goat IgG conjugated with Texas Red (1:200). After incubating the secondary antibody, incubate at room temperature in the dark for 2 hours, and finally wash with PBS buffer solution 3 times for 5 minutes each time; Dropwise add a mounting medium with anti-quenching DAPI, and after mounting, develop with a fluorescence microscope and take pictures for analysis.

[0053] 9. TUNEL Staining

[0054] The paraffin-embedded brain tissues were subjected to TUNEL staining using a TUNEL kit (In Situ Cell Death Detection Kit, Roche, Germany) to detect apoptosis (Shen, H., et al., Role of Neurexin-1betaandNeuroligin-1in Cognitive DysfunctionAfter SubarachnoidHemorrhage inRats. Stroke, 2015. 46(9): p. 2607-15). The brain tissue sections were deparaffinized by heating at 70 °C for 2-4 hours and rehydrated in xylene and a graded series of ethanol concentrations. After washing three times with phosphate-buffered saline, the sections were incubated with the TUNEL reaction mixture at 37 °C for 1 hour. The sections were washed 3 times with phosphate-buffered saline and then covered with an anti-quenching mounting medium containing DAPI. Finally, TUNEL-positive neurons in each sample were observed using a fluorescence microscope (Nikon, Japan), and the image data were analyzed using Image J software (National Institutes of Health, USA).

[0055] 10. Result Analysis

[0056] (1) Overall Observation

[0057] There were no significant changes in body temperature and body weight in rats in each experimental subarachnoid hemorrhage group. The mortality rate of rats in the sham operation group was 0% (0 / 42), and the mortality rate of rats in each experimental group was 17.81% (23 / 247). In addition, rats with a score ≤ 7 in previous evaluations were excluded.

[0058] (2) Subarachnoid Hemorrhage Promotes IL-33 Expression

[0059] Western blotting was performed on brain tissues after subarachnoid hemorrhage to detect the expression of IL-33 after subarachnoid hemorrhage. The changes in the localization and expression of IL-33 protein within 72 hours after subarachnoid hemorrhage are as Figure 3 shown. In the figure, β-actin was used as an internal control for IL-33. Figure A shows the Western blot bands of IL-33 at 3, 6, 12, 24, and 72 hours after subarachnoid hemorrhage or sham operation; Figure B shows the quantitative analysis of the relative IL-33 protein levels; Figure C shows representative images of IL-33 (green), NeuN (red) / GFAP (red) / Iba-1 (red), and DAPI (blue) in the temporal basal cortex 24 hours after subarachnoid hemorrhage or sham operation; scale bar = 50 μm; data are expressed as mean ± SD; n = 3 in Figures A - C, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, compared with the sham operation group; N.S., no significant difference.

[0060] The results showed that, compared with the sham operation group, subarachnoid hemorrhage promoted the expression level of IL-33 in the temporal base brain tissue. The results of immunofluorescence also showed that, compared with the sham operation group, subarachnoid hemorrhage significantly increased the expression level of IL-33 in the temporal base brain tissue, and it was mainly expressed in astrocytes.

[0061] (3) Subarachnoid hemorrhage promotes ST2 expression

[0062] Western blotting was performed on the brain tissue after subarachnoid hemorrhage to detect the expression of ST2 after subarachnoid hemorrhage.

[0063] The localization and expression changes of ST2 protein within 72 hours after subarachnoid hemorrhage were as Figure 4 shown. In the figure, β-actin was used as the internal control for IL-33. Figure A shows the Western blot bands of ST2 at 3, 6, 12, 24, and 72 hours after subarachnoid hemorrhage or sham operation; Figure B shows the quantitative analysis of the relative ST2 protein level; Figure C shows the representative images of ST2 (green), NeuN (red) / GFAP (red) / Iba-1 (red), and DAPI (blue) in the temporal base cortex 24 hours after subarachnoid hemorrhage or sham operation; scale bar = 50 μm; data are expressed as mean ± SD; n = 3 in Figures A - C, *P≤0.05, **P≤0.01, ***P≤0.001, compared with the sham operation group; N.S., no significant difference.

[0064] The results showed that, compared with the sham operation group, subarachnoid hemorrhage promoted the expression level of ST2 in the temporal base brain tissue. The results of immunofluorescence also showed that, compared with the sham operation group, subarachnoid hemorrhage significantly increased the expression level of ST2 in the temporal base brain tissue, and it was mainly expressed in microglia.

[0065] (4) IL-33 improves short-term neurological deficits induced by subarachnoid hemorrhage

[0066] Through two behavioral tests, the effect of IL-33 treatment on short-term neurobehavior was explored. The effect of IL-33 on the neurobehavioral outcomes caused by subarachnoid hemorrhage was as Figure 5 shown. In the figure, Figure A shows the effect of IL-33 intervention on the modified Garcia scores at 24 and 72 hours after subarachnoid hemorrhage in rats; Figure B shows the effect of IL-33 intervention on the balance beam test scores at 24 and 72 hours after subarachnoid hemorrhage in rats; Figure C shows the effect of IL-33 intervention on the brain edema conditions of the left brain, right brain, cerebellum, and brainstem at 24 and 72 hours after subarachnoid hemorrhage; *P≤0.05, **P≤0.01, ***P≤0.001, compared with the sham operation group; N.S., no significant difference.

[0067] The results showed that compared with the sham operation group, all rats in the subarachnoid hemorrhage group showed lower modified Garcia scores and beam balance test scores within 1 week after subarachnoid hemorrhage, indicating that subarachnoid hemorrhage induced short-term sensory and motor deficits. In addition, this short-term sensory and motor deficit was effectively restored after IL-33 treatment. Brain water content was measured at 24 and 72 hours after subarachnoid hemorrhage induction to determine whether IL-33 treatment affected brain edema. The results showed that compared with the sham operation group, the brain water content of rats in the subarachnoid hemorrhage group was significantly increased, indicating that subarachnoid hemorrhage induced brain edema. In addition, compared with the subarachnoid hemorrhage group, this condition was alleviated in the IL-33 treatment group.

[0068] (5) IL-33 improves neuronal apoptosis after subarachnoid hemorrhage

[0069] The effect of IL-33 administration on neuronal apoptosis was analyzed by TUNEL staining, and the results are as Figure 6 shown. In the figure. Representative images of TUNEL (green), NeuN (red), and DAPI (blue) in the temporal basal cortex 24 hours after subarachnoid hemorrhage or sham operation; scale bar = 50 μm.

[0070] The results of TUNEL staining showed that compared with the sham operation group, apoptosis of cells in the temporal basal cortex was significantly increased after subarachnoid hemorrhage. Compared with the subarachnoid hemorrhage group, neuronal apoptosis was significantly reduced in the IL-33 administration group, and IL-33 regulated neuronal apoptosis by reducing the level of reactive oxygen species.

[0071] (6) IL-33 promotes M2 polarization of microglia

[0072] The effect of IL-33 administration on microglia in the temporal basal cortex after subarachnoid hemorrhage was analyzed by immunofluorescence staining, and the results are as Figure 7 shown. In the figure, Figure A is a representative image of Iba-1 (red) and DAPI (blue) in the temporal basal cortex 24 hours after subarachnoid hemorrhage or sham operation; scale bar = 50 μm; Figure B shows the number of microglial cell branches in the temporal basal cortex, Figure C shows the number of cell endings, and Figure D shows the change in the length of cell branches; data are expressed as mean ± SD; n = 3 in Figures A - D; *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, compared with the sham operation group; N.S., no significant difference.

[0073] The results of immunofluorescence staining showed that compared with the subarachnoid hemorrhage group, IL-33 administration significantly increased the number of microglial cell branches, the number of endings, and the branch length, and IL-33 promoted M2 polarization of microglia after subarachnoid hemorrhage.

[0074] In summary, Western blotting, immunofluorescence staining, TUNEL staining, and behavioral tests were used to explore the polarization of microglia and the possible pathways to alleviate neuronal apoptosis. It was demonstrated that IL-33 treatment might regulate M2 polarization of microglia after subarachnoid hemorrhage through ST2, and further inhibit neuronal apoptosis (the neuroprotective functional mechanism of IL-33 is as Figure 8 shown). The results showed that exogenous IL-33 treatment could activate the ST2 receptor, thereby promoting M2 polarization of microglia and playing a neuroprotective role in the progression of subarachnoid hemorrhage. IL-33 treatment could improve the short-term neurobehavioral outcomes of rats induced by subarachnoid hemorrhage.

[0075] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Application of IL-33 in the preparation of drugs for treating and / or alleviating brain damage after subarachnoid hemorrhage.

2. The use according to claim 1, characterized in that: The IL-33 alleviates the short-term motor deficit induced by subarachnoid hemorrhage.

3. The use according to claim 1, characterized in that: The IL-33 alleviates subarachnoid hemorrhage-induced cerebral edema.

4. The use according to claim 1, characterized in that: The IL-33 alleviates subarachnoid hemorrhage-induced neuronal apoptosis.

5. The use according to claim 1, characterized in that: The IL-33 activates the ST2 receptor and promotes the M2 polarization of microglia after subarachnoid hemorrhage.

6. The use according to claim 1, characterized in that: The IL-33 increases the number of branches, the number of terminals and the length of branches of microglia after subarachnoid hemorrhage.

7. The use according to claim 1, characterized in that: The IL-33 improves prognosis after subarachnoid hemorrhage.

8. The use according to claim 1, characterized in that: The active ingredient of the drug includes IL-33.

9. The use according to claim 8, characterized in that: The medicament further includes a pharmaceutically acceptable carrier.

10. The use according to claim 8, characterized in that: The content of IL-33 in the drug is 60-100wt%.

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