FGF21对前脂肪细胞分化和胰腺癌纤维化的影响的实验研究OA

Background and purpose:The mechanism underlying fibrotic alterations in pancreatic cancer(PC)remains unclear.This study aimed to explore the role of preadipocyte differentiation in PC and the effects of fibroblast growth factor 21(FGF21)on preadipocyte differentiation and PC fibrosis.Methods:Conditioned media were prepared using 3T3-L1 cells at different differentiation stages to observe their effects on Panc02 PC cell clone formation,cell viability,cell cycle,and apoptosis.Panc02 conditioned medium was used to culture 3T3-L1 cells,and the degree of preadipocyte differentiation was evaluated by Oil Red-O staining.Transcriptome sequencing was employed to identify differentially expressed genes between cells from different treatment groups.Western blot was used to detect protein expression levels of fibroblast activation protein(FAP),preadipocyte factor-1(Pref-1),uncoupling protein-1(UCP-1),and β-actin.An orthotopic PC model was established in C57BL/6 mice by injecting Panc02 cells(Con group),a preadipocyte co-injection model was established by co-injecting Panc02 and 3T3-L1 cells(Model group),and the intervention effect of FGF21 was observed by intraperitoneal injection of FGF21 in the Model group(FGF21 group).Tumor growth was compared among groups using small-animal in vivo imaging and tumor weight measurement.Tumor pathological structure was observed by HE staining and Masson staining,and protein expression levels of α-smooth muscle actin(α-SMA),FAP,and Pref-1 were evaluated by immunohistochemical staining.The expression levels of FGF21 in PC and normal pancreatic tissues were analyzed using the Cell-omics Data Coordinate Platform,Gene Expression Omnibus,and The Human Protein Atlas.This animal experiment was approved by the Ethics Review Committee for Animal Experimentation Projects of the Department of Laboratory Animal Science at Fudan University(approval No.2019JS-020).Results:Long-term culture with preadipocyte conditioned medium promoted PC cell proliferation(P<0.05).PC cell conditioned medium inhibited preadipocyte maturation and differentiation(P<0.01),and the affected differentially expressed genes were significantly enriched in lipid metabolism pathways.FGF21 promoted preadipocyte maturation and differentiation(P<0.01)and antagonized the inhibitory effect of PC cells on preadipocyte maturation and differentiation(P<0.05).This effect was associated with the upregulation of lipogenic gene expression by FGF21.Compared with the Con group,the Model group showed faster tumor growth(P<0.05),higher tumor weight(P<0.01),increased tumor fibrosis,richer collagen fibers,elevated protein expression of α-SMA(P<0.01)and FAP(P<0.01),and no significant difference in Pref-1 protein expression(P>0.05).Compared with the Model group,the FGF21 group exhibited slower tumor growth(P<0.05),lower tumor weight(P<0.01),reduced tumor fibrosis,decreased collagen fibers,and lower protein expression of α-SMA(P<0.05),FAP(P<0.01),and Pref-1(P<0.05).FGF21 expression was lower in human PC tissues than in normal pancreatic tissues.Conclusion:Preadipocytes maintain their fibroblast-like phenotype in the tumor microenvironment,thereby promoting fibrotic changes and malignant proliferation in PC.FGF21 can exert an inhibitory effect on PC by promoting the maturation and differentiation of preadipocytes.