ABSTRACT
Objective To evaluate the role of M3 receptor in penehyclidine hydrochloride(PHC)-induced reduction of increased permeability of human pulmonary microvascular endothelial cells (PMVECs) caused by endotoxin and the relationship with mitogen-activated protein kinase (MAPK) signaling pathway.Methods Human PMVECs were seeded in 6-well plates (2 ml/hole) or in culture flasks (4 ml/flask) at the density of 1 × 105 cells/ml and randomly divided into 6 groups (n=5 each):control group (group C),M3 receptor shRNA transfection group (group shRNA),lipopolysaccharide (LPS) group,penehyclidine plus LPS group (group P+LPS),LPS plus M3 receptor shRNA transfection group (group LPS+shRNA) and PHC plus LPS plus M3 shRNA transfection group (group P+LPS+shRNA).The cells were transfected with shRNA plasmid containing 2.5 nmol/L M3 receptors in shRNA,LPS+shRNA and P+LPS+shRNA groups.LPS at the final concentration of 0.1 μg/ml was added at 24 h of incubation and then cells were incubated for 1 h in LPS and LPS+shRNA groups.PHC at the final concentration of 2 μg/ml was added at 24 h of incubation,cells were incubated for 1 h,then LPS at the final concentration of 0.1 μg/ml was added,and cells were incubated for another l h in P+LPS and P+LPS+shRNA groups.The permeability of PMVECs was measured using Transwell assay.The expression of phosphorylated p38 MAPK (p-p38 MAPK)and phosphorylated extracellular signal-regulated protein kinase 1/2 (p-ERK1/2) was detected by Western blot,the expression of heat shock protein 27 (HSP27) using immunofluorescent staining,and the expression of M3receptor mRNA by real-time polymerase chain reaction.Results Compared with group C,M3 receptor mRNA expression was significantly down-regulated in group shRNA,and the permeability of cells was significantly increased,and the expression of p-p38 MAPK,p-ERK1/2,HSP27 and M3 receptor mRNA was up-regulated in group LPS (P＜0.05).The permeability of cells was significantly decreased,and the expression of p-p38 MAPK,p-ERK1/2,HSP27 and M3 receptor mRNA was down-regulated in P+ LPS,LPS+shRNA and P+LPS+shRNA groups as compared with group LPS,and in group P+LPS+shRNA as compared with group LPS+shRNA (P＜0.05).Conclusion The mechanism by which PHC reduces endotoxin-caused increased permeability of human PMVECs is related to inhibiting activation of MAPK signaling pathway after down-regulating M3 receptor.
ABSTRACT
Objective To investigate the expression of scavenger receptor A(SR-A) in rat liver tissues during acute obstructive suppurative cholangitis(AOSC) and its relations with inflammatory mediators and hepatic injury.Methods Wistar rat models of AOSC were reproduced by ligating choledochus and inside injecting Escherichia coli O111∶B4.The plasma endotoxin concentrations,TNF-? levels and expressions of SR-A protein and mRNA in liver tissues were assayed by limulus test,ELISA,immunohistochemistry and RT-PCR,respectively.Pathological changes of liver tissues were observed under light microscope.Results With the time prolonged,the plasma endotoxin concentrations and the TNF-? levels gradually increased,but the SR-A protein and mRNA expressions decreased in the rats of experimental group,significantly different with those in sham operation group and normal saline group(P