Inhibition Of Poly(I:C) On The Secretion Of Adiponectin And Its Receptor Expression In Mice Visceral Adipose

BackgroundVirus infection can destroy the function of mouse adipose tissue,which leads to the occurrence of metabolic diseases.Polyinosinic polycytidylic acid [poly(I:C)],as a viral double stranded RNA(double-stranded RNA dsRNA)analogs,can activate pattern recognition receptors(pattern recognition receptors,PRRs)including Toll like receptor 3(Toll-like receptor 3,TLR3),retinoic acid inducible gene I(retinoic acid induced gene I,RIG-I)and melanoma differentiation associated protein 5(melanoma differentiation related proteins 5,MDA5),and imitate the virus infection to induce innate immune.However,the effect of poly(I:C)stimulation on the adipose tissue still unknown,and the mechanism undererlying the poly(I:C)-caused endocrine function disorder needs further study.ObjectiveTo investigate the effect of Poly(I:C)on the expression of adiponectin and its receptor in adipose tissue of mice,observe the changes of lipid metabolism in mice,and to explore the possible mechanism of Poly(I:C)on lipid metabolism.Methods1.Animal modeling: C57BL/6 male mice with similar body weight and week 8 weeks were randomly selected and injected with 5?l of Poly(I:C)per gram of body weight by intraperitoneal injection as the experimental group,and the control group were injected intraperitoneally with 5?l PBS buffer per gram of body weight and injected once ecah day for a total of four injections;2.Weight and glucose tolerance test: Measure mouse body weight daily and glucose tolerance with glucose meter.3.Quantitative real-time PCR(qRT-PCR): Detect the expression of inflammatory factorsand adiponectin in adipose tissue;4.Hematoxylin-eosin staining(HE)and immunohistochemical staining: Adipose and epididymal tissues of the mice were collected after Poly(I: C)or PBS treatment and stained to observe changes and the level of TNF-? in adipose tissue;5.Enzyme-linked immunosorbent assay(ELISA): the level of serum adiponectin and insulin were detected;6.Western Blot:Detect the protein expression of inflammatory factors and adiponectin in adipose tissue.Results1.Compared with the control group,mice injected intraperitoneally with Poly(I: C)lost weight,and the blood glucose level of mice injected with Poly(I:C)decreased on the third day,and the level of lipid returned to normal on the fifth day,the level of serum insulin elevated.The blood glucose level was higher than that of the control group on the seventh day,but the blood glucose level was in a state of disorder,the level of serum insulin decerased significantly.2.A large number of inflammatory cells were infiltrated in the mouse adipose tissue injected with Poly(I:C),and the infiltration of inflammatory cells increased with the number of days of injection.3.Compared with the control group,the expression of inflammatory factor TNFalpha and PRR such as TLR3?RIG-I?MDA5 were increased in adipose tissue of mice injected with Poly(I:C),and immunohistochemical staining also showed that TNF-alpha increased in adipose tissue.4.Compared with the control group,serum adiponectin level was decreased in mice injected with Poly(I:C),adiponectin and its receptor expression in adipose tissue decreased,but adiponectin receptor protein level remained unchanged.ConclusionIntraperitoneal injection Poly(I:C)induce inflammatory reaction in visceral adipose tissue of mice,reduce body weight,blood glucose and serum insulin levels weredisordered,and promote the expression of TNF-? and pattern recognition receptors in visceral adipose tissue.Poly(I:C)can activate the body's innate immune response and inhibit the expression of adipose tissue adiponectin and its receptors.