摘要
目的研究丙咪嗪对脂多糖(LPS)诱导的小鼠单核巨噬细胞(RAW264.7)NLRP3炎症小体激活的影响并探讨其可能的作用机制。方法 CCK-8检测丙咪嗪对RAW264.7细胞活性的影响;用不同浓度丙咪嗪预先处理RAW264.7细胞2 h后再用LPS处理细胞8 h,Western blot法检测酸性鞘磷脂酶(ASM)、NLRP3、caspase-1、白细胞介素(IL)-1β和IL-18的蛋白表达水平;细胞免疫荧光法检测神经酰胺(Cer)的含量变化;ELISA法检测炎性因子IL-1β和IL-18的释放水平。结果与对照组相比,LPS(1 mg/L)能增加RAW264.7细胞ASM的蛋白表达和Cer的含量(P<0.01);上调细胞中NLRP3、caspase-1、IL-1β和IL-18的蛋白表达水平以及细胞上清液IL-1β和IL-18的释放水平(P<0.01)。而经丙咪嗪预先处理能够显著抑制LPS所致ASM和Cer的改变(P<0.01);可明显抑制细胞中NLRP3、caspase-1、IL-1β和IL-18的蛋白表达以及细胞上清液中IL-1β和IL-18的释放(P<0.05,P<0.01)。结论丙咪嗪可通过调控ASM/Cer通路,抑制NLRP3炎症小体的激活从而发挥抗炎活性。
Objective To investigate the protective effect and possible mechanism of imipramine on LPS-induced NLRP3 inflammasome activation in RAW264.7 macrophages. Methods The effect of imipramine on RAW264.7 cells viability were detected by CCK-8 method. RAW264.7 cells were pretreated with different concentrations of imipramine for 2 hours and then treated with LPS for 8 hours. The protein expression of acid sphingomyelinase(ASM), NLRP3, caspase-1, interleukin-1β(IL-1β) and IL-18 were determined by Western blot; the content of ceramide(Cer) was detected by the method of cell immunofluorescence; the release levels of inflammatory cytokine IL-1β and IL-18 were measured by ELISA. Results Compared with the control group, LPS(1 mg/L) significantly increased ASM protein expression and the content of Cer in RAW264.7 cells(P<0.01); LPS(1 mg/L) significantly up-regulated the protein expression levels of NLRP3, caspase-1, IL-1β and IL-18 as well as the release levels of IL-1β and IL-18 in the supernatants(P<0.01). However, pretreatment with imipramine significantly inhibited ASM and Cer changes induced by LPS(P<0.01); It significantly inhibited the protein expression levels of NLRP3, caspase-1, IL-1β and IL-18 as well as the release levels of IL-1β and IL-18 in the supernatants(P<0.05, P<0.01). Conclusion Imipramine exerts anti-inflammatory activity by inhibiting the activation of NLRP3 inflammasome through the regulation of ASM/Cer pathway.
引文
[1] Maslove D M,Wong H R.Gene expression profiling in sepsis:timing,tissue,and translational considerations[J].Trends Mol Med,2014,20(4):204-13.
[2] Lu N,Wang L,Cao H,et al.Activation of the epidermal growth factor receptor in macrophages regulates cytokine production and experimental colitis[J].J Immunol,2015,192(3):1013-23.
[3] Strowig T,Henao-Mejia J,Elinav E,et al.Inflammasomes in health and disease[J].Nature,2012,481(7381):278-86.
[4] 胡波,张晓刚,李德才.miR-22靶向抑制NLRP3基因对冠心病内皮细胞炎症损伤的保护作用[J].安徽医科大学学报,2018,53(5):668-75.
[5] Yang J,Qu J M,Summah H,et al.Protective effects of imipramine in murine endotoxin-induced acute lung injury[J].Eur J Pharmacol,2010,638(1–3):128-33.
[6] Laura L,Montserrat M,Carmen G R,et al.Critical role of acidic sphingomyelinase in murine hepatic ischemia-reperfusion injury[J].Hepatology,2010,44(3):561-72.
[7] Guo H,Callaway J B,Ting J P.Inflammasomes:mechanism of action,role in disease,and therapeutics[J].Nat Med,2015,21(7):677-87.
[8] Vandanmagsar B,Youm Y H,Ravussin A,et al.The NLRP3 inflammasome instigates obesity-induced inflammation and insulin resistance[J].Nat Med,2011,17(2):179-88.
[9] Tibboel J,Reiss I,de Jongste J C,et al.Ceramides:a potential therapeutic target in pulmonary emphysema[J].Respir Res,2013,14(1):1-12.
[10] Yang Y,Uhlig S.The role of sphingolipids in respiratory disease[J].Ther Adv Respir Dis,2011,5(5):325-44.