CTRP13 Induces Hepatic Sinusoid Dysfunction By Regulating Autophagy Through AMPK/mTOR Signal Pathway Under High Glucose

Objective: To investigate the regμlation of C1q/ tumor necrosis factor-related protein 13 on hepatic sinusoid function and related autophagy signal pathway under high glucose,so as to provide a new theoretical basis for the basic research and clinical prevention and treatment of diabetes mellitus complicated with fatty liver.Methods: 8-week-old male Wistar rats were divided into three groups: control group(n =10),simple fatty liver group(n = 10),diabetes mellitus combined with fatty liver group(n =30).The histopathological characteristics of liver were observed by HE and hexaamine silver staining,and the expression of CTRP13 in liver tissue was detected by immunohistochemistry.Rat hepatic sinusoidal endothelial cells were cμltured and rLSECs24 h,CTRP13 lentivirus overexpression vector(LV-CTRP13)and lentivirus empty vector(LV-CON)were treated with glucose(25 mmol/L)to transfect rLSECs.AMPK inhibitor compound C,m TOR inhibitor Torin1,autophagy inhibitor(3murmethyladenine,3MA)was used for intervention.The activity of rLSECs was detected by MTT colorimetry and the final experimental group was determined.The effects of high glucose and LV-CTRP13 transfection on rLSECs autophagosomes were observed by transmission electron microscope.The m RNA and protein expression of CTRP13,AMPK,Mtor,Beclin-1,LC3II/I and PLVAP were detected by RT-PCR and Western blotting.Result:1.HE staining showed that lipid droplets of different sizes appeared in the liver cells of diabetic rats with fatty liver,and the fatty degeneration was enhanced,and the arrangement of hepatic lobules was disordered;The results of hexamine silver staining showed that the formation of basement membrane increased,and the reticular fibers of hepatic portal vein collapsed,fused and thickened in diabetic rats with fatty liver;Immunohistochemistry showed that the expression of ctrp13 in liver tissue of diabetic rats with fatty liver was significantly lower than that of the other two groups.2.Under high glucose,the expression of CTRP13 decreased,the expression of autophagy-related proteins Beclin-1 and LC3II/I decreased,and the expression of PLVAP increased(P < 0.001).3.Transmission electron microscope: the number of autophagosomes in HG group was less than that in NC group,and the number of autophagosomes in high glucose + LV-CTRP13 group was higher than that in HG group.4.LV-CTRP13 transfection increased the expression of p-AMPK,decreased the expression of p-m TOR,increased the expression of Beclin-1 and LC3II/I,and reversed the high expression of PLVAP induced by high glucose(P < 0.001).5.AMPK inhibitor Compound C increased the expression of p-m TOR,decreased the expression of Beclin-1 and LC3II/I and increased the expression of PLVAP;m TOR inhibitor Torin1 increased the expression of Beclin-1 and LC3II/I and decreased the expression of PLVAP;in addition,autophagy inhibitor 3MA further decreased the expression of Beclin-1and LC3II/I and increased the expression of PLVAP in rLSECs on the basis of high glucose(P< 0.05).Conclusion: Lv-ctrp13 transfection activates autophagy through AMPK / m TOR signaling pathway,reduces plvap expression induced by high glucose and alleviates hepatic sinusoidal dysfunction.