The Effect And Mechanism Research Of Gasdermin D On Angiotensin Ⅱ-induced Abdominal Aortic Aneurysm In ApoE-deficient Mice

Background:Abdominal aortic aneurysm（AAA）is a fatal cardiovascular disease characterized by the pathological expansion of the aortic wall.The incidence of contemporary abdominal aortic aneurysms is on the rise,and the mortality rate of rupture of tumors is as high as 90%.At present,AAA is treated mainly by surgery,and there is no effective intervention for patients with diameters less than 55mm,slow tumor dilation and inability to withstand surgery.Therefore,it is important to find effective drugs for its pathogenesis.Studies have shown that inflammatory reactions play an important role in the onset of AAA,including the current research hot spot NLRP3 inflammasome pathway.Gasdermin D（GSDM D）is a key target protein downstream of the NLRP3 inflammasome pathway,so GSDM D is an important target for suppressing inflammatory responses caused by the NLRP3inflammasome pathway.Disulfiram is a clinically used drug for chronic alcoholism and has been shown to be effective in suppressing GSDM D proteins in human or mouse cells.Objective:In this experiment,we constructed angiotensin Ⅱ-induced ApoE knockout mouse AAA models,used disulfiram to inhibit GSDM D proteins in mice,and then observed the effects of the drug on AAA in mice and explored their mechanisms.Methods:The ApoE^-/-mice were randomly divided into two groups,with micropulations buried under the back of the neck and continuous pumping into Ang Ⅱ to model the AAA in mice.The disulfiram group used disulfiram irrigation and the control group used saline irrigation.Monitored the weight and blood pressure of two groups of mice.Compared the survival rate and the severity of AAA of two groups.ELISA method was used to detect the concentration of IL-18 and IL-1βin the serum of two groups,and to evaluate local pathological changes in arterial walls by immunohistochemistry,HE staining and elastic fiber staining.Results:There was no significant difference in body weight,systolic blood pressure and diastolic blood pressure on day 0,day 7,day 14,day 21,and day 28 of the two groups of mice（P>0.05）.There was no significant difference in survival rate between the two groups of mice（P>0.05）.Compared with the control group,the disulfiram group mice’s abdominal aorta dilatation,tumor formation rate and AAA severity were significantly lower than those of the control group（P<0.01）.Immunohistochemistry showed that disulfiram inhibits the expression of mouse GSDM D protein and is an effective inhibitor of GSDM D.The serum IL-1βconcentration of mice in the disulfiram group was significantly lower than that of the control group（P<0.05）,there was no significant difference in the serum IL-18 concentration of the two groups of mice（P>0.05）.HE showed that the inflammatory reaction in the abdominal aorta of the disulfiram group was significantly reduced,and immunohistochemistry showed that the inflammatory-related indicators（including CD4,CD8 and CD68）and matrix metalloproteinases in the abdominal aorta of the disulfiram group（MMP2 and MMP9）were significantly reduced.The elastic fiber staining showed that the collagen fibers of the abdominal aorta wall of the control group were obviously proliferated,the collagen fibers and elastic fibers were arranged disorderly.The proliferation of collagen fibers and the breakage of elastic fibers in the abdominal aorta wall of mice in the disulfiram group were significantly weakened.Conclusion:Disulfiram can inhibit the formation and expansion of AAA induced by angiotensin Ⅱ in ApoE knockout mice,reduce inflammatory cell immersion,matrix metalloproteinase（MMP2 and MMP9）expression in local aortic,and abdominal aortic wall damage.The mechanism may be related to the inhibition of GSDM D expression in mouse cells and the reduction of IL-1βconcentration in the serum.