丝裂原活化蛋白激酶8基因在3T3-L1细胞诱导分化中表达水平的变化及肿瘤坏死因子-α对其调节的作用  

Expression of Mitogen-Activated Protein Kinase 8 Gene during 3T3-L1 Preadipocytes Differentiation and Regu-lative Role of Tumor Necrosis Factor-Alpha

作　　者：金子林[1] 朱从龙[2] 郭锡熔[1] 倪毓辉[1] 王玢[1] 潘晓琴[1] 周炯英[3] 陈荣华[1] 

机构地区：[1]南京医科大学儿科医学研究所 [2]淮阴市第一人民医院,江苏淮阴223300 [3]常熟市第二人民医院,江苏常熟215500

出　　处：《实用儿科临床杂志》2006年第7期391-394,共4页Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金项目资助(39870362);江苏省自然科学基金项目资助(BK99136);江苏省教委自然科学基金项目资助(98KJB320002);淮安市科技项目资助(HSA04027)

摘　　要：目的 观察丝裂原活化蛋白激酶8（MAPK8）基因在3T3-L1脂肪前体细胞诱导分化过程中表达水平的变化，探讨TNF-α1对成熟脂肪细胞中MAPK8基因表达水平的调节作用，分析MAPK8基因与脂肪细胞分化、脂质形成及肥胖问的关系。方法体外培养3T3-L1脂肪前体细胞，在诱导其分化成熟的基础上，采用RT-PCR技术检测诱导分化不同时段（0～10d）脂肪细胞中MAPK8基因的表达水平；应用重组TNF-α（0．1，1．0，10．0μg／L）干预分化成熟的脂肪细胞，采用RT-PCR技术检测1NF-α干预后不同时间（0．5，2，6，12，24h）脂肪细胞中MAPK8基因的表达水平。结果 1．3T3-L1前体脂肪细胞中，MAPK8基因表达水平较高。应用地塞米松（DEX）、1-甲基-3-异丁基黄嘌呤（MIX）、胰岛素后脂肪细胞逐渐分化成熟，MAPK8基因mRNA表达水平逐渐减低。MAPK8基因表达水平除在诱导分化前至d4、d2～5、d6～10时段内无显著性差异外（P均〉0．05），余各时段问表达水平均有显著差异（P均〈0．01）；2．不同浓度重组TNF-α干预成熟脂肪细胞，均能显著上调MAPK8基因的表达，并呈现随TNF-α浓度增加、刺激时间延长，表达调控作用逐渐增强的总体趋势。TNF-α浓度为0．1μg／l，时，MAPK8基因的表达水平于干预12h时间点开始出现明显上调；浓度增加至1．0μg／L,时，MAPK8基因表达水平开始显著上调的时间点提前至干预2h时，但24h时间点的表达水平未见继续上调；TNF-α浓度为10．0μg／L时，除2h时间点MAPK8基因表达开始显著上调外，12～24h时段的表达也呈上调趋势。结论 1．MAPK8基因在3T3-L1细胞分化过程中表达逐渐下调，其机制可能有利于脂肪细胞的分化成熟和脂质积聚，与肥胖发生有关；2．TNF-α能够上调成熟脂肪细胞中MAPK8基因的表达，其效应总体趋势上呈现剂量及时间反应性特征。Objective To observe the changes of mitogen-activated protein kinase 8 （MAPKS） gene expression during 3T3-L1 preadipocytes differentiation. To explore the regulative role of tumor necrosis factor-alpha（TNF-α） on MAPK8 gene expression in matured adipocytes. To analyze the relationship between the differential expression of MAPK8 gene and adipoeyte’ differentiation, adipogenesis and obesity. Methods 3T3-L1 preadipocytes were cultured in vitro and differentiated into the matured adipoeytes by insulin, 3-isobutyl-1-methyxanthine （MIX）,and dexamethasone （DEX）. TNF-α in different concentrations （0.1,1.0,10.0μg/L） was added into the culture medium of fully differentiated adipocytes （d10） for various periods （0.5,2,6,12,24 h）. Total RNA of these cells was extracted and the levels of MAPK8 gene mRNA expression were evaluated by RT-PCR. Results 1. In preadipoeytes, the level of MAPK8 gene rnRNA expression remained high. In the presence of DEX, MIX and insulin, with the 3T3-L1 preadipocytes bein.g differentiated into the matured adipocytes, the level of MAPK8 gene mRNA expression was downregulated and reached the lower＇level in fully differentiated adipocytes. There was significant difference between any 2 detected phases in the levels of MAPK8 gene mRNA expression （all P 〈 0.01 ）, except that the levels of MAPK8 g ene mRNA expression did not decrease obviously in the stage of pre-differentiation to d4, d2 to dS, d6 to d10 （all P〉0.05） ;2. Treatment of d10 3T3-L1 adipocytes with TNF-α of different concentrations resulted in the significant increase in the level of MAPK8 gene mRNA expression. The activated effect of TNF-α on MAPK8 gene mRNA expression generally tended to be reinforced with the increasing concentrations of TNF-α and the elongation of time course. When 0.1μg/L TNF-α was applied, the level of MAPK8 gene expression was found to significantly increase at 12 h. While 1.0μg/L TNF-α was used, the level of MAPK8 gene expression significantly increased at 2 h. Howe

关 键 词：丝裂原活化蛋白激酶8基因 3T3-L1脂肪细胞 脂肪细胞分化 肿瘤坏死因子-Α 

分 类 号：R723.14[医药卫生—儿科]