Zeng Hui, Tang Zhong-Yang, Zhang Feng, Li Hui-Hua, Liu Li-Hui, Zhou Hong-Hao, Hu Min-Yu, Liu Zhao-Qian
Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University Xiang-Ya School of Medicine, Hunan, P.R. China.
Clin Chem Lab Med. 2007;45(9):1199-206. doi: 10.1515/CCLM.2007.252.
The aim of the present study was to investigate whether histamine induces up-regulated expression of uncoupling protein 2 (UCP2) and fat acid-binding protein (aP2) in white adipocytes (differentiated 3T3-L1 cells).
Differentiation of 3T3-L1 preadipocytes to adipocytes was induced by the addition of 5 microg/mL insulin, 1 micromol/L dexamethasone, 10 mmol/L 1-isobutyl-3-methylxanthine, 1% dimethylsulfoxide, and 10% fetal bovine serum in Dulbecco's modification of Eagle's medium. Total RNA from differentiated 3T3-L1 cells was extracted and semi-quantitative RT-PCR was performed to determine the levels of UCP2 and aP2 mRNA. The expression level of UCP2 protein was determined by Western blot analysis.
Histamine at a concentration of 30 micromol/L significantly increased the expression of UCP2 mRNA and UCP2 protein, and expression levels reached a peak value. There were significant differences in the expression levels of UCP2 mRNA and UCP2 protein in adipocytes treated with 30 micromol/L histamine at various time points within 48 h, and their levels reached a peak value after 6 h of incubation. In addition, histamine increased the expression level of aP2 mRNA in adipocytes. Expression of aP2 mRNA in adipocytes reached the highest value at a concentration of 20 micromol/L histamine after 6-h incubation. Finally, we found that diphenhydramine (a H1 receptor antagonist) significantly decreased expression levels of UCP2 mRNA and protein, as well as aP2 mRNA. There were significant differences in expression levels of UCP2 and aP2 mRNA in adipocytes treated at concentrations of 20 micromol/L histamine and diphenhydramine, respectively.
These data reveal that histamine up-regulated the expression of UCP2 and aP2 in vitro in white adipocytes.
本研究旨在探究组胺是否能诱导白色脂肪细胞（分化的3T3-L1细胞）中解偶联蛋白2（UCP2）和脂肪酸结合蛋白（aP2）的表达上调。
通过在杜氏改良伊格尔培养基中添加5μg/mL胰岛素、1μmol/L地塞米松、10mmol/L 1-异丁基-3-甲基黄嘌呤、1%二甲基亚砜和10%胎牛血清，诱导3T3-L1前脂肪细胞分化为脂肪细胞。提取分化的3T3-L1细胞的总RNA，并进行半定量逆转录聚合酶链反应（RT-PCR）以测定UCP2和aP2 mRNA的水平。通过蛋白质免疫印迹分析确定UCP2蛋白的表达水平。
浓度为30μmol/L的组胺显著增加了UCP2 mRNA和UCP2蛋白的表达，且表达水平达到峰值。在48小时内的不同时间点，用30μmol/L组胺处理的脂肪细胞中，UCP2 mRNA和UCP2蛋白的表达水平存在显著差异，孵育6小时后其水平达到峰值。此外，组胺增加了脂肪细胞中aP2 mRNA的表达水平。孵育6小时后，脂肪细胞中aP2 mRNA的表达在组胺浓度为20μmol/L时达到最高值。最后，我们发现苯海拉明（一种H1受体拮抗剂）显著降低了UCP2 mRNA和蛋白以及aP2 mRNA的表达水平。分别用20μmol/L组胺和苯海拉明处理的脂肪细胞中，UCP2和aP2 mRNA的表达水平存在显著差异。
这些数据表明，组胺在体外可上调白色脂肪细胞中UCP2和aP2的表达。
