To Explore The Changes Of Th1/Th2/Th17-related Inflammatory Factors And HIF-α Levels In Patients With Intracranial And Extracranial Atherosclerotic Stenosis And The Effect Of HIF-α On Microglia

Objective: In this project,the levels of IFN-γ,IL-4,IL-17 A and HIF-α in serum samples of patients with different degrees of intracranial and extracranial atherosclerotic stenosis confirmed by cerebral angiography were detected.To analyze the difference and correlation of IFN-γ,IL-4,IL-17 A and HIF-α expression in patients with severe stenosis,especially with and without collateral circulation perfusion.In addition,since microglia play an indispensable role in ischemic brain injury,we also investigated the effect of HIF-α on M1 polarization of microglia to find a new direction for inhibiting microglia polarization and thus protecting ischemic brain injury.Methods: Clinical study-Blood samples of patients diagnosed with ischemic cerebral infarction by the department of Neurology of our hospital and examined by cerebral angiography were collected and divided into 5 groups according to the inclusion criteria and the degree of intracranial and extracranial atherosclerotic stenosis,with at least 30 cases in each group,and30 cases of healthy personnel from the physical examination center of our hospital were collected as the control group.ELISA kit was used to test the expression levels of IFN-γ,IL-4,IL-17 A and HIF-α in each group,and the clinical data and past history of patients were analyzed and compared.Experimental study-BV-2 cells were stimulated with HIF-αrecombinant protein and divided into 6 groups according to different irritating concentrations.M1 and M2 microglia cell population were observed and analyzed by flow cytometry.Western Blot was used to detect p-STAT1 protein and NF-κβ p65 protein in M1 polarized JAK2/STAT1/NF-κβpathway.Results: The expression levels of IFN-γ,IL-4,IL-17 A and HIF-α in normal control group,non-atherosclerotic stenosis group and mild atherosclerotic stenosis group were significantly decreased compared with severe atherosclerotic stenosis group(P < 0.05).There were no significant differences in IFN-γ,IL-4,IL-17 A and HIF-α levels in the groups with and without collateral circulation.IFN-γ,IL-4,IL-17 A and HIF-α are correlated with each other,suggesting that they may play a role in the development of intracranial and extracranial atherosclerotic stenosis.ROC curve analysis indicated that IFN-γ,IL-4 and HIF-α could be used as diagnostic factors for intracranial and extracranial atherosclerotic stenosis and had good diagnostic effect.Binary Logistic regression analysis showed that HCY,Hb Alc and HIF-α were independent risk factors for intracranial and extracranial atherosclerotic stenosis(P<0.05).The M1-type polarization of BV-2 cells stimulated by recombinant HIF-α was observed under confocal immunomicroscopy,and the M1-type polarization of microglia induced by HIF-α might be mediated by NF-κβ-related pathway,but STAT1-related pathway might not be involved,as the concentration of HIF-α stimulation increased.NF-κβ p65 protein expression increased,but p-STAT1 had no significant difference.Conclusion: The levels of IFN-γ,IL-4,IL-17 A and HIF-α are different in patients with different degrees of intracranial and extracranial large atherosclerotic stenosis,and the expression of IFN-γ,IL-4,IL-17 A and HIF-αincreases with the aggravation of the stenosis.IFN-γ,IL-4,IL-17 A and HIF-αare expected to be new targets for the diagnosis and treatment of intracranial and extracranial atherosclerotic stenosis.In addition,microglia play an important role in ischemic brain injury.We found that HIF-α promotes M1 polarization of microglia,which may be realized through NF-κβ related pathways.