Cocl_2诱发急性化学缺氧对非酒精性脂肪肝小鼠的影响

The effect of Cocl_2-induced acute chemical hypoxia on nonalcoholic fatty liver mice

目的探讨二氯化钴(Cocl_2)诱发急性化学缺氧对非酒精性脂肪肝小鼠的影响及成纤维细胞生长因子21(FGF21)的作用机制。方法将30只雄性C57BL/6小鼠随机分为正常饮食组(control组)、高脂饮食组(HFD组)、高脂饮食+Cocl_2缺氧处理组(HFD+Cocl_2组),每组10只;喂养8周后收集3组小鼠血清及肝脏组织。使用自动生化分析仪检测血清中空腹血糖、TG、TC、ALT水平;ELISA法检测小鼠血清中FGF21的含量;HE染色、三色染色法观察肝脏组织形态学改变;Q-PCR法检测基质金属蛋白酶抑制剂-1(TIMP-1)、缺氧诱导因子1α(HIF-1α)、FGF21 m RNA表达;Western blot法检测FGF21、c-Jun氨基末端激酶(JNK)、X-盒-结合蛋白-1(XBP-1)蛋白表达。结果与control组比较,HFD组、HFD+Cocl_2组小鼠血清中空腹血糖、TC、ALT、FGF21水平均明显升高(均P<0.05),肝脏内纤维化程度加重,肝脏组织TIMP-1、FGF21 m RNA以及FGF21、p-JNK、XBP-1蛋白表达均明显增加。与HFD组比较,HFD+Cocl_2组小鼠血清中TG、ALT、FGF21水平均明显升高(均P<0.05),肝脏纤维化程度明显加重,肝脏组织TIMP-1、FGF21 m RNA以及FGF21、p-J NK、XBP-1蛋白表达均进一步增加。结论 Coc l2诱发急性化学缺氧可加重非酒精脂肪肝小鼠的肝脏损伤,上调FGF21的表达;内质网应激反应可能是缺氧诱导脂类代谢障碍的调控途径。

Objective To investigate the effect of Cocl_2-induced acute chemical hypoxia on FGF21 expression in nonalcoholic fatty liver mice. Methods Thirty male C57 BL/6 mice were randomly divided into three groups with 10 in each group:normal diet group(control), high fat diet group(HFD), high fat diet plus cobalt chloride hypoxia group(HFD+Cocl_2). The animals were sacrificed after 8 weeks of feeding and serum samples and liver tissue were collected. The levels of fasting blood glucose,TG, TC and ALT were measured by automatic biochemical analyzer. The content of FGF21 in serum was detected by ELISA. The morphological changes of liver tissue were observed with HE staining and three colors staining. The expression of TIMP-1,HIF-1 a and FGF21 mRNA was detected by Q-PCR, and the expression of FGF21, JNK and XBP-1 protein was detected by Western blot. Results Compared with control group, the serum levels of fasting blood glucose, TC, ALT and FGF21 in HFD group and HFD+Cocl_2 group were significantly increased(P <0.05), the formation of intrahepatic fibrosis in HFD group and HFD+Cocl_2 group was aggravated, the expressions of TIMP-1, FGF21 mRNA and FGF21, p-JNK, XBP-1 protein in liver tissue of HFD group and HFD+Cocl_2 group were up-regulated(P<0.05). Compared with the HFD group, the levels of TG, ALT and FGF21 in the serum of HFD+Cocl_2 group were further increased(P<0.05). The formation of intrahepatic fibrosis in HFD+Cocl_2 group was more aggravated. The expression of TIMP-1, FGF21 mRNA and FGF21, p-JNK and XBP-1 protein in the liver of HFD+Cocl_2 group were increased more markedly. Conclusion Acute chemical hypoxia aggravates liver injury in nonalcoholic fatty liver mice and up-regulates the expression of FGF21. The endoplasmic reticulum stress might be the pathways of hypoxia-induced lipid metabolism disorder.