Li Hongli, He Ying, Zhang Jianjun, Sun Shuhan, Sun Baogui
Department of Cardiology, Shanghai Jiaotong University Affiliated First People's Hospital, 85 Wujin Road, Shanghai 200080, PR China.
Cell Biol Int. 2007 Aug;31(8):831-5. doi: 10.1016/j.cellbi.2007.01.034. Epub 2007 Jan 30.
Lipopolysaccharide (LPS) is a potent activator of cells of the immune and inflammatory systems, including macrophages, monocytes, and endothelial cells (EC). Toll-like receptor 4 (TLR4) has been identified as the primary receptor for LPS. Vascular smooth muscle cells (VSMCs) likely contribute significantly to the inflammation induced by low-level LPS in patients who are at risk for atherosclerosis. Previous study indicated that functional TLR4 was present in VSMCs. However, it remains unclear whether low levels of commercial LPS preparations can affect TLR4 expression in early stage. Here Real-time quantitative PCR analysis was used to detect TLR4 mRNA expression; Immunofluorescence, Western blot analysis and flow cytometry were used to examine TLR4 protein expression. It was shown that TLR4 was present in Human Aortic Smooth Muscle Cells (HASMCs). LPS can up-regulate TLR4 mRNA and protein expression in HASMCs in dose- and time-dependent manner. These data indicate that LPS regulate TLR4 expression in HASMCs.
脂多糖（LPS）是免疫和炎症系统细胞的强效激活剂，包括巨噬细胞、单核细胞和内皮细胞（EC）。Toll样受体4（TLR4）已被确定为LPS的主要受体。血管平滑肌细胞（VSMC）可能在动脉粥样硬化风险患者中由低水平LPS诱导的炎症中起重要作用。先前的研究表明功能性TLR4存在于VSMC中。然而，尚不清楚低水平的商业LPS制剂在早期是否会影响TLR4表达。在这里，使用实时定量PCR分析来检测TLR4 mRNA表达；使用免疫荧光、蛋白质印迹分析和流式细胞术来检测TLR4蛋白表达。结果表明，TLR4存在于人主动脉平滑肌细胞（HASMC）中。LPS可以剂量和时间依赖性方式上调HASMC中TLR4 mRNA和蛋白表达。这些数据表明LPS调节HASMC中TLR4表达。
