Study on the mechanism of polyethylene glycol losenatide improving non-alcoholic fatty liver disease by regulating lipophagy

CHEN Xunxun; ZHANG Jielei

doi:10.3969/j.issn.1006-5725.2025.11.002

Abstract：Objective To investigate the mechanism of polyethylene glycol losenatide in improving non-alcoholic fatty liver disease by regulating lipophagy.Methods(1)32 C57BL/6 male mice were fed normally for 1 week and randomly divided into 4 groups with 8 mice in each group.Normal control group(fed normal diet),Normal+GLP-1RA(intraperitoneal injection of polyethylene glycol losenatide 0.3 mg/kg q3d),High fat group(fed with high fat diet),High-fat+GLP-1RA(on the basis of high-fat diet,intraperitoneally injected polyethylene glycol losenatide 0.3 mg/kg q3d),The molding lasts 16 weeks.Body weight,blood glucose and glucose tolerance test(GTT)were measured at the end of 16 weeks.Serum total cholesterol(TC),triglyceride(TG),low density lipoprotein(LDL),high density lipoprotein(HDL)and other indexes were detected by Enzyme-linked immunosor-bent assay(ELISA),liver pathological changes were observed by Hematoxylin-eosin(HE)and oil red O sections,and the expression of microtubule-associated protein light chain 3(LC3),autophagy adaptor protein(P62),and transcription factor EB(TFEB).in liver were detected by Western blot(Wb).(2)The cell was divided into normal group(treated with bovine serum albumin,BSA);Normal+polyethylene glycol losenatide group(BSA+100 nmol/L GLP-1RA),High fat group(0.5 mmol/L PA);High fat+polyethylene glycol losenatide group(0.5 mmol/L PA+100 nmol/L GLP-1RA).After 24 h,the steatosis was observed by oil red O staining,the levels of TG in the supernatant were detected,Wb analysis was performed to detect protein expression levels of LC3,TFEB,and P62.Reverse transcription quantitative PCR(RT-qPCR)was used to measure mRNA levels of lipid synthesis-related factors.Results(1)Compared with normal control group,the body weight and blood glucose of mice in the high fat group increased significantly(P<0.01),reduced glucose tolerance(P<0.01),the levels of TC,TG and LDL in serum in liver of high fat group were significantly increased(P<0.01),while HDL was significantly decreased(P<0.01).Compared with high fat group,blood sugar in mice,the levels of TC,TG and LDL in serum and P62 in liver of high fat+GLP-1 group were significantly decreased(P<0.01);Glucose tolerance,HDL and and the protein expressions of LC3,TFEB were significantly increased(P<0.01).Compared with normal control group,the above indexes in normal+GLP-1 group were not significantly changed(P>0.05).(2)In vitro,The NAFLD HepG2 cell model was successfully constructed with 0.5 mmol/L PA.After 24 h of PA treatment,intracellular lipid drops were significantly increased(P<0.01),intracellular TG and the mRNA levels of lipid synthesis-related factors in the cells were increased(P<0.01).High fat+GLP-1 group improved the fatty degeneration induced by high fat,and the changes of the above indexes showed an opposite trend but the expres-sion of LC3,TFEB were significantly increased(P<0.01),lipid regulatory factor P62 protein in liver were decreased(P<0.01).Conclusion Polyethylene glycol losenatide can improve non-alcoholic fatty liver disease by regulating lipophagy.