氧自由基降低脂肪细胞脂联素表达的机制研究

Study on mechanism of reactive oxygen species in regulating adiponectin expression in adipocytes

目的研究活性氧簇（ROS）对3T3-L1脂肪细胞脂联素表达的调节机制。方法以实时定量PCR检测分化成熟的3T3-L1脂肪细胞脂联素mRNA表达水平，联合应用多重磷酸化蛋白分析系统与各种蛋白激酶抑制剂，筛查ROS下调脂联素表达的信号通路。结果作为一种重要的ROS，H2O2激活了3T3-L1脂肪细胞细胞外信号调节激酶1／2（ERK1／2）、c—Jun氨基端激酶（JNK）、蛋白激酶B（Akt）、pTOS6激酶（pTOS6K）及Janus激酶／信号转导和转录激活因子（JAK／STAT）等多种信号转导通路。其中Akt和JAK／STAT抑制剂完全逆转H2O2对脂联素表达的下调作用（均P〈0．01）。结论ROS可能通过激活Akt、JAK／STAT信号途径下调脂肪细胞脂联素的表达，从而在肥胖及其相关疾病的发生、发展中发挥作用。

Objective To investigate the signaling cascades involved in the regulatory effects of reactive oxygen species（ROS） on adiponectin expression in 3T3-L1 adipocytes. Methods 3T3-L1 cells were cultured and differentiated into mature adipocytes. Adiponectin mRNA expression was evaluated by quantitative real-time PCR. The signaling pathways associated with ROS-decreased adiponectin expression were screened by Bioplex phosphoprotein assays and various protein kinase inhibitors. Results As an important ROS, H2 O2 activated several signaling pathways including extracellular signal regulated protein kinase 1/2 （ERK1/2） , c-Jun N-terminal kinase （JNK）, protein kinase B （Akt）, p70 S6 kinase （p70 S6K） , and Janus kinase/sigual transducer and activator of transcription （JAK/STAT）. Akt and JAK/STAT inhibitors completely reversed H2O2-decreased adiponectin expression（ both P〈0.01 ）. Conclusions ROS markedly down-regulates adiponectin expression in 3T3-L1 adipocytes by activating Akt and JAK/STAT signaling pathways ,which may contribute to the development of obesity and its related diseases.