Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, P.O. Box 14115-331, Tehran, Iran.
Inflammation. 2011 Feb;34(1):43-8. doi: 10.1007/s10753-010-9206-3.
The factors responsible for regulating PTP1B expression in certain metabolic states have been unclear. We investigated the effects of palmitate on PTP1B gene transcription in C2C12 myotubes and myotubes co-cultured with J774A.1 macrophages. PTP1B mRNA and promoter activity levels were measured in C2C12 myotubes and direct or indirect co-culture of myotubes with macrophages using real time PCR and luciferase activity, respectively. Palmitate significantly induced PTP1B mRNA and promoter activity levels 1.36- and 1.32-fold, respectively, in C2C12 cells compared with the untreated myotubes. Palmitate showed a 2.3-fold increase in PTP1B mRNA level in myotubes co-cultured indirectly with macrophages. PTP1B promoter activity was also significantly induced by palmitate in direct (1.8-fold) and indirect (1.48-fold) co-culture of myotubes with macrophages. These data suggest that while palmitate treatment significantly induced PTP1B expression at the transcriptional level, the presence of an inflammatory process exerted by macrophages can augment this effect in the muscle cells.
导致某些代谢状态下 PTP1B 表达调节的因素尚不清楚。我们研究了棕榈酸酯对 C2C12 肌管和成肌细胞与 J774A.1 巨噬细胞共培养物中 PTP1B 基因转录的影响。使用实时 PCR 和荧光素酶活性分别在 C2C12 肌管和成肌细胞与巨噬细胞的直接或间接共培养物中测量 PTP1B mRNA 和启动子活性水平。与未经处理的肌管相比，棕榈酸酯使 C2C12 细胞中的 PTP1B mRNA 和启动子活性水平分别显著增加了 1.36 倍和 1.32 倍。棕榈酸酯在与巨噬细胞间接共培养的肌管中使 PTP1B mRNA 水平增加了 2.3 倍。棕榈酸酯还显著诱导了肌管与巨噬细胞直接（1.8 倍）和间接（1.48 倍）共培养物中的 PTP1B 启动子活性。这些数据表明，虽然棕榈酸酯处理在转录水平上显著诱导了 PTP1B 的表达，但巨噬细胞产生的炎症过程可以增强肌肉细胞中的这种作用。
