Mechanism Of Action Of Angelica Sinensis Polysaccharide On Mitochondrial Autophagy In The Kidneys Of Diabetic KK-Ay Mice Through The AMPK Pathway

ObjectiveTo study the effect of Angelica sinensis polysaccharide(ASP)on diabetic nephropathy(DN),and to investigate the effect of angelica polysaccharide on the AMP-activated protein kinase(AMPK)signaling pathway and mitochondrial autophagy in KK-Ay mice.MethodsTo study the effect of Angelica sinensis polysaccharide(ASP)on diabetic nephropathy(DN),and to investigate the effect of angelica polysaccharide on the AMP-activated protein kinase(AMPK)signaling pathway and mitochondrial autophagy in KK-Ay mice.method10 male C57BL/6J mice and 50 male KK-Ay mice were adaptively fed with KK-Ay rat feed for 1 week.KK-Ay mice were randomly divided into model group,irbesartan group,angelica polysaccharide high,medium and low dose group,and C57BL/6J mice were normal control groups,with 10 mice in each group.Each drug group was given the corresponding drug gavage once daily for 4 weeks.Observe the mice in general,weigh them weekly and measure the mice’s blood glucose.At the end of the fourth week,the mice were taken from the heart and sacrificed,and serum was isolated to detect biochemical indexes such as urine microalbumin(U-ALB),creatinine(SCr),urea nitrogen(BUN),total cholesterol(TC),triglycerides(TG),and lowdensity lipoprotein(LDL-C).HE staining,light microscopy to observe kidney tissue changes;Western blot method detected the expression of mitochondrial autophagy-related proteins LC3,P62,Nix and the expression of mitochondrial fission protein Drp1.Immunohistochemistry(IHC)detected the expression of AMPK and mTOR proteins in mouse kidney tissues.Realtime PCR to detect AMPK and mTOR mRNA expression in mouse kidney tissue.ResultsCompared with the blank control group,the model group had more drinking and eating,increased urine output,loose stool,curled up and lazy,poor mental state,easy to shed fur and even skin ulcers.The levels of FBG,U-ALB,SCr,BUN,TC,TG,and ldl-C in the model group were significantly increased(P < 0.01),and the differences were statistically significant.Loose tubular arrangement,a large number of vacuolar degeneration of renal tubular epithelial cells,atrophy of the glomerulus,and inflammatory cell infiltration;The expression of mitophagyrelated proteins LC3Ⅱ/LC3Ⅰ.and Nix were upregulated(P < 0.01),P62 expression decreased(P < 0.01),mitochondrial fission protein Drp1 expression was upregulated(P < 0.01),AMPK,mTOR protein and mRNA expression were significantly increased(P < 0.01),and the differences were statistically significant.Compared with the model group,the urine output of the high-dose group of angelica sinensis polysaccharide and the irbesartan group decreased,the stool was shaped and not loose,the fur was slightly glossy,the skin ulcers were reduced,and the mental state gradually improved.The levels of FBG,U-ALB,SCr,BUN,TC,TG,LDL-C were reduced to varying degrees in the dose group of angelica sinensis polysaccharide and the irbesartan group(P < 0.05),and the dose-dependent drug group of angelica sinensis polysaccharide was dose-dependent.The pathological morphology of renal histologies was improved,the arrangement of renal cells was gradually tightened,the vacuolar degeneration and inflammatory cells of renal tubular epithelial cells were reduced,and glomerular atrophy was reduced.The expression of mitophagy-related proteins LC3Ⅱ/LC3Ⅰ.,Nix was downregulated(P < 0.05,P < 0.01),and P62 expression increased(P < 0.05).Mitochondrial fission protein Drp1 expression is downregulated(P < 0.01);The expression of AMPK,mTOR protein and mRNA was significantly reduced(P < 0.01),and the difference was statistically significant.ConclusionAngelica sinensis polysaccharides can improve kidney damage in DN mice,improve renal function,reduce hyperglycemia and hyperlipidemia in DN mice,thereby delaying the occurrence and development of DN,by inhibiting mitochondrial fission and mitochondrial autophagy hyperphagy in DN mice kidneys,so that mitochondrial autophagy reaches dynamic balance,thereby reducing mitochondrial damage,the protective mechanism of angelica polysaccharides on DN mice may be related to inhibition of AMPK signaling pathway mediated renal mitochondrial autophagy.