Ang ?-induced NOX4 Overexpression Contributes To ROS Generation And Adipokine Secretion In 3T3-L1 Adipocyte Could Be Inhibited By Simvastatin:the Molecular Signalling Mechanisms

Background:Obesity is one of the risk factors for coronary artery disease,and obesity is involved in the pathophysiological processes of multiple diseases,such as multiple sclerosis,diabetes,insulin resistance [1][2][3].Adipose tissue is not only able to store energy,but also can secrete a variety of hormones,cytokines,and metabolities(fat factor,etc),these substances control systemic energy balance by adjusting the feeding signal of the central nervous system and peripheral tissue metabolic activity [4].In a variety of pathological conditions(such as coronary heart disease,obesity,etc.),ROS production is excessive and the balance of antioxidant system in vivo is broken,which can cause a series of pathological reactions.Renin-angiotensin aldosterone system for blood vessels have a variety of biological effects,the research has proved that angiotensin original gene expression inhibited by RNA interference could inhibit differentiation of 3T3-L1 preadipocyte,that indicates adipose tissue renin angiotensin system(RAS)is related with fat metabolism [5].Due to obesity,the hyperactive renin-angiotensin system(RAS)in adipose tissue plays an important role in obesity-related diseases such as hypertension and type 2 diabetes.Adipose tissue local RAS is regulating the fat cells proliferation and differentiation factor secretion and glucolipid metabolism through a paracrine or autocrine way,which in turn aggravate insulin resistance,affect the body's overall glucolipid metabolic state [6].Statins are essential in the treatment of dyslipidemia,and autophagy is a critical step in the process of differentiation and maturation [7].Studies have found that RAS blockers can promote differentiation of adipocyte,and improve sensitivity of insulin [8].Whether the synergistic effect of simvastatin and angiotensin receptor antagonists can be used as a new strategy to treat abnormal blood lipid metabolism is very profound.In the process of metabolism of fat cells both Ang? and autophagy are important parts,while NOX4 and LC3B-?,p62 protein expression and the interaction between these factors has not been reported.Objective: This study was to explore Ang? in 3T3-L1 adipocytes induced by oxidative stress reaction and adipokine secretion,to demonstrate the biological effect of simvastatin in the process and molecular mechanism.Methods :(1)In vitro,cultured of 3T3-L1 preadipocyte and induced differentiation to mature;(2)application of CCK8 kits with different doses of Ang?-treated adipose cell activity and different time of intervention;(3)flow cytometry was applied to detect ROS production in fat cells after different drug interventions.(4)ELISA kit was used to detect leptin and Adiponectin levels in the cell supernatant;(5)the Western Blot method(immune protein imprinting)was to detect the expression levels of NOX4,LC3B-?,p62.Results:(1)Ang?reduce 3T3-L1 adipose cell activity in dose/time-dependent manner;(2)Ang? induced 3T3-L1 adipocytes secrete increased leptin which could be inhibit by simvastatin;(3)Ang? promoted 3T3-L1 adipocytes to generate the active oxygen free species which could be inhibit by simvastatin;(4)Ang? induced NOX4 upexpression in 3T3-L1 adipocytes;(5)simvastatin inhibits Ang? induced LC3B-?,p62 / SQSTM1 protein upexpression.Conclusion : AngII can significantly increase the expression of NOX4 in 3T3-L1 adipocytes,resulting in a significant increase in ROS production and leptin secretion,and simvastatin can inhibit the production of ROS and leptin secretion by upregulating the expression of LC3B-? and p62 in 3T3-L1 adipocyte thus to play a protective role.