摘要目的 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.

abstractsObjective 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.