Abstract: Objective To observe the effects and mechanisms of Apelin-13 on expression of pyroptosis related proteins in aorta of diabetic mice. Methods C57/BL mice of eight weeks old were used as control group;kkAy mice of eight weeks old were used as type 2 diabetic models;osmotic pumps were used to treat kkAy mice with apelin-13 at a rate of 30 μg/(kg·d),and L-NAME(eNOS inhibitor) was injected intraperitoneally at a dose of 10 mg/(kg·d) to kkAy mice. Blood was collected for detection of Hb1Ac. The aortae were harvested and fixed. Morphological changes were observed with HE staining. Expression of eNOS,NLRP3,caspase-1 and gasdermin D were measured with immunohistochemical staining. Results Compared to the control group, the level of eNOS in the aorta of diabetic mice was significantly higher than that in control mice (P＜0.05),the levels of NLRP3,caspase-1 and gasdermin D were also higher than that in control mice. After apelin-13 treatment,the expressions of eNOS,NLRP3,caspase-1 and gasdermin D were further increased (P＜0.05). After L-NAME and apelin-13 treatment, the expressions of eNOS, NLRP3,caspase-1 and gasdermin D were reduced as compared to apelin-13 treatment alone(P＜0.05). Conclusions Apelin-13 may promote the expression of pyroptosis related protein in aortic cells by increasing eNOS/NO pathway,which would induce structural and functional damage in diabetic arteries.

Key words: diabetes, aorta, apelin-13, pyroptosis, eNOS