Xiao Bolin, Chen Meifang, Yang Mei, Xiao Zhilin
Department of Geriatric Cardiology; National Center for Clinical Research of Geriatric Diseases, Xiangya Hospital, Central South University, Changsha 410008; School of Stomatology, Lanzhou University, Lanzhou 710000, China.
Department of Geriatric Cardiology; National Center for Clinical Research of Geriatric Diseases, Xiangya Hospital, Central South University, Changsha 410008, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2018 Dec 28;43(12):1301-1308. doi: 10.11817/j.issn.1672-7347.2018.12.004.
To investigate the effects of adenosine triphosphate (ATP) on expression of inflammatory factors induced by lipopolysaccharide (LPS) in endothelial progenitor cells (EPCs), and to elucidate the possible mechanisms. Methods: Mononuclear cells were isolated from human umbilical cord blood by density gradient centrifugation, RT-PCR was performed to detect the expression of inflammatory factors induced by LPS (1 mg/mL) in EPCs, the effect of low concentration (5 μmol/L) of ATP on expression of IL-1β, MCP-1 and ICAM-1, and the effect of different concentrations (5, 50 μmol/L) of ATP on the expression of Toll-like receptor (TLR) 4, myeloid differentiation primary response protein 88 (MyD88) and CD14. Western blot was performed to detect expression of TLR4 regulated proteins MyD88 and CD14 or to detect the low concentration (1, 5 μmol/L) of ATP on the expression of TLR4, MyD88 and CD14 and the NF-κB signaling pathway. Results: EPCs highly expressed TLR4, and its ligand LPS (1 mg/mL) significantly upregulated mRNA expression of IL-1β, MCP-1 and ICAM-1 and protein expression of MyD88 and CD14 in a time-dependent manner (P<0.01), accompanied by activation of ERK and NF-κB signal pathway. ATP at low concentration (5 μmol/L) significantly inhibited LPS-induced mRNA expression of IL-1β, MCP-1 and ICAM-1(P<0.05), downregulated the LPS-induced protein expression of TLR4, MyD88 and CD14 in EPCs (P<0.05), and suppressed LPS-induced activation of NF-κB signaling pathway (P<0.05). Conclusion: ATP at low concentration may suppress LPS-induced expression of inflammatory factors in EPCs through negative regulation of the TLR4 signaling pathway.
探讨三磷酸腺苷（ATP）对脂多糖（LPS）诱导的内皮祖细胞（EPCs）炎症因子表达的影响，并阐明其可能机制。方法：采用密度梯度离心法从人脐带血中分离单个核细胞，运用RT-PCR检测LPS（1mg/mL）诱导的EPCs中炎症因子的表达，低浓度（5μmol/L）ATP对IL-1β、MCP-1和ICAM-1表达的影响，以及不同浓度（5、50μmol/L）ATP对Toll样受体（TLR）4、髓样分化初级反应蛋白88（MyD88）和CD14表达的影响。采用蛋白质免疫印迹法检测TLR4调节蛋白MyD88和CD14的表达，或检测低浓度（1、5μmol/L）ATP对TLR4、MyD88和CD14表达及NF-κB信号通路的影响。结果：EPCs高表达TLR4，其配体LPS（1mg/mL）能显著上调IL-1β、MCP-1和ICAM-1的mRNA表达以及MyD88和CD14的蛋白表达，且呈时间依赖性（P<0.01），同时伴有ERK和NF-κB信号通路的激活。低浓度（5μmol/L）ATP能显著抑制LPS诱导的IL-1β、MCP-1和ICAM-1的mRNA表达（P<0.05），下调LPS诱导的EPCs中TLR4、MyD88和CD14的蛋白表达（P<0.05），并抑制LPS诱导的NF-κB信号通路激活（P<0.05）。结论：低浓度ATP可能通过负调控TLR4信号通路抑制LPS诱导的EPCs炎症因子表达。
