妊娠期与雌雄非妊娠期大鼠代谢综合征中肝脏HNF1α-NF-κB信号轴变化及其性别差异研究OA

Objectives:To investigate how the hepatic HNF1α-NF-κB signaling axis responds to inflammatory signals under metabolic stress induced by a high-calorie diet,and to elucidate the regulatory patterns of this process in rats of different sexes and during pregnancy. Methods:Rat models of metabolic syndrome(MetS)and gestational metabolic syndrome(GMS)were established using a high-calorie diet combined with 5％fructose in drinking water in male and female rats.In vitro experiments were conducted using hepatocyte cell lines derived from different sexes(female-derived Mahlavu cells and male-derived HepG2 cells).Serum levels of the inflammatory cytokines interleukin-1β(IL-1β)and interleukin-6(IL-6)were detected by the enzyme-linked immunosorbent assay(ELISA).The gene and protein expression of hepatocyte nuclear factor 1α(HNF1α),the nuclear factor kappaB(NF-κB)subunit RELA,and inflammatory factors in liver tissues and cells were examined by quantitative reverse transcriptase PCR(qRT-PCR)and Western blot.Oil red O staining was used to observe the accumulation of lipid droplets in hepatocytes. Results:In the GMS model,when compared with the control group,serum IL-1β and IL-6 levels in the model group showed an increasing trend without statistical significance(P＞0.05).Hepatic HNF1αprotein and mRNA expression levels were significantly decreased(P＜0.01),and RELA protein expression level was also decreased(P＜0.05).In the MetS model,when compared with the controls,female rats in the model group exhibited significantly lower serum IL-1β and IL-6 levels(P＜0.05),along with significantly reduced hepatic mRNA expression levels of IL-6 and TNF-α(P＜0.01).Concurrently,hepatic RELA protein and mRNA expression levels were decreased(P＜0.05),while hepatic HNF1αprotein and mRNA levels showed a decreasing trend without statistical significance(P＞0.05).In male rats of the MetS model,serum IL-1β and IL-6 levels showed an increasing trend when compared with the controls,but the differences were not statistically significant(P＞0.05).Hepatic mRNA expression levels of IL-6 and TNF-α were decreased(P＜0.05),and both mRNA and protein expression levels of hepatic RELA and HNF1α were significantly reduced(P＜0.05).Treatment with free fatty acids(FFA)induced lipid droplet accumulation in both Mahlavu and HepG2 hepatocyte lines,which led to a significant decrease in the mRNA expression levels of inflammatory cytokines(P＜0.01)and a significant decrease in RELA mRNA expression levels(P＜0.05)in both cell lines.Furthermore,HNF1α protein and mRNA expression levels were reduced in both cell lines,with a significant decrease observed in Mahlavu cells(P＜0.05). Conclusions:Sex differences exist in metabolic inflammation induced by a high-calorie diet.The liver may act as a target organ for circulating inflammatory cytokines rather than their primary source.Male rats appear more sensitive to metabolic stress,while maternal tolerance to metabolic stress decreases during pregnancy.Hepatic down-regulation of HNF1α,accompanied by suppression of RELA and inflammatory factors,is more pronounced in male rats.