氯化钴体外诱导低氧促进脂肪细胞炎症反应

目的 以氯化钴体外模拟低氧，研究低氧与脂肪细胞炎症的关系，并探讨其可能的作用机制。方法 将3T3-L1前脂肪细胞诱导分化为成熟的脂肪细胞，加入氯化钴处理，体外模拟低氧状态，利用实时荧光定量PCR及Western印迹法检测低氧诱导因子1α( HIF-1α)、葡萄糖转运蛋白1(Glut1)、脂肪因子、炎症因子等mRNA和蛋白表达水平及炎症相关信号通路变化。结果 200 μmol/L氯化钴显著上调3T3-L1脂肪细胞HIF-1α及Glut1表达，同时促进内质网应激相关基因C/EBP同源蛋白(CHOP)、葡萄糖调节蛋白(GRP)78的mRNA表达增加，脂联素的表达水平下降，抵抗素和瘦素的mRNA表达水平增加。另外，环氧合酶2、白细胞介素6等炎症因子基因的mRNA水平表达也明显上调，NF-κB的抑制蛋白IκBα的磷酸化水平增加。结论低氧状态可能通过激活NF-κB炎症信号通路诱导脂肪细胞产生炎症。

Cobalt chloride-induced hypoxia stimulates inflammatory response in adipocytes

Objective To explore the relationship between hypoxia induced by cobalt chloride( CoCl2 ) and inflammation in 3T3-LI adipocytes, and the underlying molecular mechanism. Methods 3T3-L1 pre-adipocytes were induced under standard differentiation process. Differentiated 3T3-L1 adipocytes were incubated with CoCl2 to induce hypoxia. The mRNA and protein expressions of hypoxia inducible factor-1 α ( HIF-1 α ), glucose transporter 1 ( Glut1 ), adipocytokines, and inflammatory cytokines, as well as the related signaling pathways were determined with quantitative realtime-PCR and Western-blot in this cell model. Results CoCl2 at the concentration of 200 μmol/L significantly up-regulated HIF-1 α and Glut1 expressions. After adipocytes were treated with CoCl2, the mRNA levels of endoplasmic reticulum stress marker genes, such as C/EBP homologous protein (CHOP) and glucose-regulated protein78 (GRP78) were markedly increased, adiponectin mRNA expression was significantly decreased, while resistin and leptin mRNA expressions were significantly increased. In addition, the mRNA expressions of cyclooxygenase 2, interleukin-6, and other inflammatory factors were also increased. The phosphorylation of IκBα,which could inhibit the activation of NF-κB, was stimulated by CoCl2. ConclusionsThe results indicate that hypoxia may induce inflammatory response via NF-κB activiation in adipocytes.