Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Department of Dermatology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Int Immunopharmacol. 2020 Jul;84:106561. doi: 10.1016/j.intimp.2020.106561. Epub 2020 May 18.
Smoking is known to have detrimental effects on cardiovascular system. However, the potential molecular basis of smoking-induced atherosclerosis remains unclear. NLRP3 inflammasome is implicated in perpetuation of inflammatory response in atherosclerosis. Therefore, we aimed to explore the cytotoxic effects of cigarette smoke condensate (CSC) on the activation of NLRP3 inflammasome in vitro and in vivo.
For in vitro study, the pro-atherogenic effects of CSC were evaluated in THP-1 monocytes with different dose concentrations (0.1, 1, 5, 10 and 20 µg/ml) for varied time periods (6, 12, 24 and 48 h). For in vivo study, 30 male C57BL/6J mice were employed. 6 mice were sacrificed for baseline investigations. 24 mice were randomly divided into four groups: Group-I:Control mice, Group-II:CSC model, Group-III:High-fat diet(HFD) model, and Group-IV:HFD + CSC model for 14 weeks (n = 6/group). The group-II and IV mice were injected with 720 µg CSC/20 g body weight intraperitoneally (6 days/week).
In vitro, higher dosage of CSC (20 µg/ml) was toxic to cells as significant decline in cell viability and proliferation was observed. Furthermore, the mRNA expression of NLRP3 inflammasome and its pro-cytokine levels were significantly augmented on CSC exposure in a dose-dependent manner but impeded in time-dependent manner. In vivo, CSC and HFD independently augmented the expression of NLRP3 inflammasome (~4-10 fold-change) along with pro-cytokine levels in Group-II and III vs Group-I mice whereas, HFD + CSC treatment demonstrated synergistic effects in Group-IV.
Our data suggest that CSC activates NLRP3 inflammasome in vitro and in vivo and collectively with HFD has synergistic effects in vivo that may promote atherosclerosis.
吸烟对心血管系统有不良影响。然而，吸烟引起动脉粥样硬化的潜在分子基础仍不清楚。NLRP3 炎性体在动脉粥样硬化中的炎症反应持续中起作用。因此，我们旨在探讨香烟烟雾冷凝物（CSC）在体外和体内对 NLRP3 炎性体激活的细胞毒性作用。
在体外研究中，用不同浓度（0.1、1、5、10 和 20μg/ml）的 CSC 处理 THP-1 单核细胞不同时间（6、12、24 和 48h），评估 CSC 的促动脉粥样硬化作用。在体内研究中，使用 30 只雄性 C57BL/6J 小鼠。6 只小鼠用于基线研究。24 只小鼠随机分为四组：I 组：对照组；II 组：CSC 模型组；III 组：高脂肪饮食（HFD）模型组；IV 组：HFD+CSC 模型组，共 14 周（每组 n=6）。第 II 组和第 IV 组小鼠每周腹腔内注射 720μg CSC/20g 体重（6 天/周）。
在体外，较高剂量的 CSC（20μg/ml）对细胞有毒性，细胞活力和增殖明显下降。此外，CSC 暴露呈剂量依赖性显著增加 NLRP3 炎性体及其前细胞因子的 mRNA 表达，但呈时间依赖性减少。在体内，CSC 和 HFD 分别独立地增加了 NLRP3 炎性体的表达（~4-10 倍）以及在第 II 组和第 III 组与第 I 组小鼠中的前细胞因子水平，而 HFD+CSC 治疗在第 IV 组显示协同作用。
我们的数据表明，CSC 在体外和体内激活 NLRP3 炎性体，与 HFD 一起在体内具有协同作用，可能促进动脉粥样硬化。
