Department of Human Anatomy, School of Basic Medical Sciences, Harbin Medical University, Harbin, Heilongjiang Province, 150081, PR China.
Department of Toxicology, Public Health School, Harbin Medical University, Harbin, Heilongjiang Province, 150081, PR China.
Chem Biol Interact. 2019 Feb 1;299:179-185. doi: 10.1016/j.cbi.2018.12.013. Epub 2018 Dec 22.
Accumulating evidences suggest that heat shock protein 60 (HSP60) and toll-like receptor 4 (TLR4) are involved in triggering inflammatory response in microglia. Paraquat (PQ) evokes microglial inflammation by up-regulating expression of HSP60-TLR4-myeloid differentiation factor 88 (Myd88)-nuclear factor-kappa B (NF-κB) in vitro. The aim of this study is to investigate the potential modulatory roles of HSP60 and TLR4 in PQ-induced inflammation. Before treated with PQ, microglia BV cells were pretreated using siRNA to knockdown HSP60 or with specific inhibitor to inhibit TLR4 expression. Expression of TLR4 and MyD88, and nuclear translocation of NF-κB subunit p65 were studied with immunoblotting and immunofluorescence, respectively. Expression of pro-inflammatory factors was assessed with quantitative real-time PCR. Knockdown of HSP60 or inhibition of TLR4 significantly reduced the expression of TLR4 and MyD88 and decreased the accumulation of NF-κB p65 in the nucleus. Gene expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) were also significantly decreased in response to PQ. These results suggest that HSP60 and TLR4 can modulate intracellular signaling of PQ-induced inflammation. Inhibiting HSP60 or TLR4 reduces significantly the intensity of inflammation in PQ-activated microglia.
越来越多的证据表明热休克蛋白 60（HSP60）和 toll 样受体 4（TLR4）参与触发小胶质细胞的炎症反应。百草枯（PQ）通过上调 HSP60-TLR4-髓样分化因子 88（MyD88）-核因子-κB（NF-κB）的表达在体外引发小胶质细胞炎症。本研究旨在探讨 HSP60 和 TLR4 在 PQ 诱导的炎症中的潜在调节作用。在用 PQ 处理之前，用 siRNA 预处理小胶质细胞 BV 细胞以敲低 HSP60 或用特异性抑制剂抑制 TLR4 表达。用免疫印迹法和免疫荧光法分别研究 TLR4 和 MyD88 的表达以及 NF-κB 亚单位 p65 的核易位。用定量实时 PCR 评估促炎因子的表达。敲低 HSP60 或抑制 TLR4 显著降低 TLR4 和 MyD88 的表达，并减少 NF-κB p65 在核内的积累。肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和诱导型一氧化氮合酶（iNOS）的基因表达也因 PQ 而显著降低。这些结果表明 HSP60 和 TLR4 可以调节 PQ 诱导的炎症的细胞内信号转导。抑制 HSP60 或 TLR4 可显著降低 PQ 激活的小胶质细胞中炎症的强度。
