棕榈酸通过上调脂肪酸转位酶诱导THP-1细胞的炎症反应

目的:探讨脂肪酸转位酶(fatty acid translocase,FAT/CD36)在棕榈酸诱导的人源单核巨噬细胞THP-1炎症反应中的作用。方法:给予不同浓度棕榈酸(0 mmol/L、0.1 mmol/L和0.2 mmol/L)处理THP-1细胞24h。Transwell迁移实验检测细胞迁移能力;real-time PCR检测CD36、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)及单核细胞趋化蛋白1(MCP-1)的m RNA表达水平;ELISA和Western blot法检测靶蛋白的蛋白含量。利用RNA干扰技术构建低表达CD36(si CD36)的THP-1细胞模型,观察抑制CD36表达对细胞迁移、炎症及趋化因子表达的影响。结果:棕榈酸促进了THP-1细胞CD36的m RNA和蛋白表达,且增强了THP-1细胞炎症/趋化因子的m RNA和蛋白表达,差异有统计学意义(P0.05)。棕榈酸处理组THP-1细胞的迁移能力明显强于对照组。与阴性对照组细胞相比,si CD36组炎症因子的m RNA和蛋白表达明显降低(P0.05),THP-1细胞迁移水平也明显降低(P0.05)。结论:棕榈酸通过上调THP-1巨噬细胞中CD36表达,促进了巨噬细胞的迁移,促使细胞产生大量炎症/趋化因子,导致巨噬细胞炎症反应。

Palmitate triggers inflammatory response by upregulating fatty acid translocase in THP-1 macrophages

AIM: To investigate the role of fatty acid translocase (FAT/CD36) on palmitate-induced inflammation in human monocyte-derived macrophage THP-1.METHODS: THP-1 cells were treated with palmitate (0, 0.1 and 0.2 mmol/L) for 24 h. Transwell chamber assay was used to examine the migration ability of THP-1 cells. The mRNA expression of CD36, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemotactic protein 1 (MCP-1) was measured by real-time PCR. The protein levels of TNF-α and IL-6 in the supernatant of cultured cells were measured by ELISA. The protein level of CD36 was examined by Western blot. Small interfering RNA (siRNA) targeting CD36 (siCD36) was used to inhibit the expression of CD36 in the THP-1 cells, and the changes of the cell migration and inflammatory response were monitored as mentioned above. RESULTS: Palmitate increased the expression of CD36 in the THP-1 cells (P<0.05). Palmitate also up-regulated inflammatory cytokine and chemokine levels, and the differences were statistically significant (P<0.05). Compared with control group, palmitate promoted migration of THP-1 cells. siCD36 was transfected into the THP-1 cells and the silencing efficiency was approximately 54%. The protein levels of TNF-α and IL-6 were also decreased in siCD36 group compared with scrambled RNA (scrRNA) group, and the differences were statistically significant (P<0.05). The migrated cells in siCD36 group were significantly less than those in scrRNA group (P<0.05).CONCLUSION: Palmitate promotes migration ability and triggers inflammatory response in the THP-1 macrophages by upregulating CD36 expression.