目的 观察Toll样受体4 (TLR4)在胰岛细胞株（INS-1）中的表达情况，探讨内毒素脂多糖（LPS）对INS-1细胞活力、胰岛素分泌功能以及TLR4表达的影响。方法 采用RT-PCR技术和Western blotting方法检测INS-1细胞和经1 mg/L LPS刺激的INS-1细胞中TLR4 mRNA和蛋白的表达变化；分别用不同质量浓度的LPS (0.01、0.1、1、5、10 mg/L) 刺激INS-1细胞，CCK8法检测细胞活力，GSIS法测定胰岛素分泌功能。结果 RT-PCR和Western blotting检测结果显示：LPS 刺激使INS-1细胞TLR4 mRNA和蛋白的表达显著增加(P<0.05)。当LPS在0.1～10 mg/L时，INS-1细胞活力受到抑制，且呈剂量时间依赖性(P<0.05)；1 mg/L LPS刺激可使高糖环境下的INS-1细胞的胰岛素分泌量显著减少(P<0.05)。结论 一定浓度范围内的LPS刺激可抑制INS-1细胞活力，并减少高糖培养条件下细胞胰岛素的分泌量。LPS刺激能上调INS-1细胞TLR4 mRNA和蛋白的表达。内毒素可能通过直接作用损伤胰岛β细胞。

Objective To investigate the expression of Toll-like receptor 4 (TLR4) on INS-1 cells, and explore the effects of lipopolysaccharide (LPS) on viability and insulin secretion of INS-1 cells and expression of TLR4 on INS-1 cells. Methods The expression of TLR4 mRNA and protein in INS-1 cells with or without treatment with 1 mg/L LPS was detected by RT-PCR and Western blotting. After treatment with different mass concentrations of LPS (0.01 mg/L, 0.1 mg/L, 1 mg/L, 5 mg/L and 10 mg/L), the viability of INS-1 cells was detected by CCK8 method, and the insulin secretion of INS-1 cells was determined by GSIS. Results RT-PCR and Western blotting revealed that the expression of TLR4 mRNA and protein in INS-1 cells was significantly increased after treatment with LPS (P<0.05). The viability of INS-1 cells was inhibited in a dose and time dependent manner after treatment with 0.1 to 10 mg/L LPS (P<0.05). The insulin secretion of INS-1 cells was significantly decreased after treatment with 1 mg/L LPS (P<0.05). Conclusion The viability of INS-1 cells is inhibited, and the insulin secretion function of INS-1 cells is decreased after treatment with LPS of certain concentrations. The expression of TLR4 mRNA and protein in INS-1 cells is increased after treatment with LPS. Pancreatic β cells may be damaged by endotoxin in a direct manner.