Sestrin1 is involved in the regulation of gluconeogenesis in mouse liver cells / 基础医学与临床

Objective To investigate the role and regulatory mechanism of stress-inducing protein 1(SESN1)in liver gluconeogenesis of fasting mice.Methods RT-qPCR was used to detect mRNA expression of SESN1 in liver tissues of C57BL/6J mice and primary mouse hepatocytes treated with forskolin(Fsk)and dexamethasone(Dex).HepG2 cells were transfected with plasmids and the effects of SESN1 overexpression on mRNA expression of gluconeogenesis related genes PGC-1α,PEPCK and G6Pase was detected by RT-qPCR.The effect of SESN1 on the promoter activity of PGC-1α in HepG2 cells was studied using a dual luciferase reporter system.The effect of SESN1 on PGC-1α deacetylation was detected by overexpression of SESN1 and inhibition of SIRT1 expression.By knocking down SIRT1 expression,we detected whether it mediated the changes in mRNA levels of SESN1 in-duced gluconeogenesis related genes.Results The mRNA expression of SESN1 was significantly increased in liver tissues of starved C57BL/6J mice and in primary hepatocytes treated with Fsk and Dex(P<0.001).Over-expression of SESN1 in HepG2 cells promoted mRNA expression of PGC-1α,PEPCK and G6Pase(P<0.001)and promoter activity of PGC-1α(P<0.001).Over-expression of SESN1 decreased the acetylation level of PGC-1α in primary hepatocytes.Sirt family inhibitors NAM and shRNA adenovirus interfered with SIRT1 expression respective-ly,and antagonized the deacetylation effect of SESN1 on PGC-1α.The expression of PGC-1α,PEPCK and G6Pase induced by SIRT1 was also significantly impaired(P<0.000 1).Conclusions SESN1 regulates liver gluconeogene-sis in mice with a SIRT1-dependent mechanism.

Nutlin-3a regulates mouse adipose function by inhibition of CIDEC expression / 基础医学与临床

Objective To investigate the effect of Nutlin-3a,a mouse double minute 2 homolog(MDM2)inhibitor,on lipid metabolism of mouse adipose.Methods High-fat diet-induced obesity(DIO)C57BL/6J mice were randomly divided into a control group injected with DMSO and an experimental group injected with Nutlin-3a.Then we conducted glucose tolerance(GTT)and insulin tolerance(ITT)tests.The epididymal white adipose tissue(eWAT),inguinal white adipose tissue(iWAT)and brown adipose tissue(BAT)of animals were isolated and microscopy of WATs with hematoxylin-eosin(HE)staining was performed to observe the morphological changes of adipocytes.The expression of lipid metabolism related gene cell death-inducing DFF45-like effector C(CIDEC)in eWAT were detected by qPCR and Western blot.Results Compared with the control group,Nutlin-3a was found to promote the body weight(P＜0.001),but no effect on glucose tolerance and insulin sensitivity in DIO mice.Nutlin-3a treatment decreased the size of adipocytes and fat deposition in adipose tissue and downregulated the mRNA and protein levels of CIDEC in eWAT.Conclusions Nutlin-3a inhibits the formation of lipid droplets by downregulating expression of CIDEC in white adipose tissue.