M3受体在盐酸戊乙奎醚减轻内毒素诱导人肺微血管内皮细胞损伤中的作用

Role of M3 receptors in penehyclidine hydrochloride-induced reduction of endotoxin-induced injury to human pulmonary microvascular endothelial cells

目的 评价M3受体在盐酸戊乙奎醚(PHC)减轻内毒素(LPS)诱导人肺微血管内皮细胞损伤中的作用.方法 正常人肺微血管内皮细胞和M3 shRNA转染人肺微血管内皮细胞,以1×105个∕ml的密度接种于6孔板(2 ml∕孔)或培养瓶(4 ml∕瓶)中,采用随机数字表法分为5组(n=5):对照组(C组)、LPS组、PHC+LPS组(P+LPS组)、LPS+M3 shRNA转染组(LPS+shRNA组)和PHC+LPS+M3 shRNA转染组(P+LPS+shRNA组).C组不给予药物处理;余各组均加入终浓度为0.1μg∕ml LPS;P+LPS组和P+LPS+shRNA组于加入LPS前1 h加入PHC 2μg∕ml;LPS+shRNA组和P+LPS+shRNA组以含2.5 nmol∕L M3受体shRNA的质粒转染细胞.加入LPS后1 h时,采用流式细胞仪测定内皮细胞纤维状肌动蛋白(F-actin)的含量;免疫荧光法检测肌球蛋白轻链激酶(MLCK)和血管内皮钙黏蛋白(VE-cadherin)的表达;Western blot法检测NF-κB p65和IκB的表达;ELISA法测定TNF-α和IL-6的含量;实时定量PCR法分别检测加入LPS后10、30和60 min时M3受体mRNA表达水平.结果 与C组比较,LPS组和P+LPS组F-actin含量降低,VE-cadherin和IκB表达下调,TNF-α和IL-6含量升高,MLCK和NF-κB p65表达上调(P<0.05);与C组比较,LPS组M3受体mRNA表达上调(P<0.05),P+LPS组差异无统计学意义(P>0.05);与LPS组比较,P+LPS组和LPS+shRNA组F-actin含量升高,VE-cadherin和IκB表达上调,TNF-α和IL-6浓度降低,MLCK、NF-κB p65和M3受体mRNA表达下调(P<0.05);与P+LPS组比较,P+LPS+shRNA组F-actin含量升高,VE-cadherin和IκB表达上调,TNF-α和IL-6浓度降低,MLCK、NF-κB p65和M3受体mRNA表达下调(P<0.05).结论 PHC可通过干扰M3受体,抑制NF-κB介导炎性反应,减轻LPS诱导的人肺微血管内皮细胞损伤.

Objective To evaluate the role of M3 receptors in penehyclidine hydrochloride ( PHC)-induced reduction of lipopolysaccharide ( LPS)-induced injury to human pulmonary microvascular endotheli-al cells ( PMVECs) . Methods Human PMVECs transfected with M3 shRNA were seeded in 6-well plates&nbsp;(2 ml∕hole) or in culture flasks (4 ml∕flask) at the density of 1×105 cells∕ml and divided into 5 groups ( n=5 each) using a random number table method: control group ( group C) , LPS group, PHC plus LPS group ( group P+LPS) , LPS plus M3 shRNA transfection group ( group LPS+shRNA) , and PHC plus LPS plus M3 shRNA transfection group ( group P+LPS+shRNA) . Group C received no mediation, and LPS was added at the final concentration of 0. 1 μg∕ml in the other groups. PHC 2 μg∕ml was added at 1 h before adding LPS in P+LPS and P+LPS+shRNA groups. The cells were transfected with plasmid containing 2. 5 nmol∕L M3 receptor shRNA in LPS+shRNA group and P+LPS+shRNA group. Contents of filamentous actin ( F-actin) in endothelial cells were measured by flow cytometry at 1 h after adding LPS. The expression of myosin light chain kinase ( MLCK) and VE-cadherin protein was examined by immunofluorescence. The ex-pression of nuclear factor kappa B ( NF-κB) p65 and IκB was detected by Western blot. Contents of tumor necrosis factor-alpha ( TNF-α) and interleukin-6 ( IL-6) were determined by enzyme-linked immunosorbent assay. The M3 receptor mRNA transcription was detected by real-time polymerase chain reaction at 10, 30 and 60 min after adding LPS. Results Compared with group C, F-actin content was significantly de-creased, the expression of VE-cadherin and IκB was down-regulated, the contents of TNF-αand IL-6 were increased, and the expression of MLCK and NF-κB p65 was up-regulated in LPS and P+LPS groups ( P<0. 05) . Compared with group C, the expression of M3 receptor mRNA was significantly up-regulated in group LPS ( P<0. 05) , and no significant change was found in group P+LPS ( P>0. 05) . Compared with group LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB was up-reg-ulated, the contents of TNF-αand IL-6 were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS and group LPS+shRNA ( P<0. 05) . Compared with group P+LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB protein was up-regulated, TNF-α and IL-6 contents were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS+shRNA ( P<0. 05) . Conclusion PHC re-duces LPS-induced injury to human PMVECs through interfering with M3 receptors and inhibiting NF-κB-mediated inflammatory responses.