ABSTRACT
Objective To evaluate the role of β-arrestin-1 in inhibition of endotoxin-induced activation of nuclear factor kappa B (NF-κB) in human pulmonary microvascular endothelial cells (HPM-VECs) by penehyclidine hydrochloride (PHC).Methods HPMVECs were seeded in 6-well plates (2 ml/hole) or in culture flasks (4 ml/flask) at the density of 1 × 105/ml,and were randomly divided into 5 groups (n =20 each) using a random number table:empty plasmid transfection group (group C),lipopolysaccharide (LPS) + empty plasmid transfection group (group LPS),PHC + LPS + empty plasmid transfection group (group P+LPS),LPS + β-arrestin-1 gene-shRNA transfection group (group LPS+shRNA) and PHC + LPS + β-arrestin-1 gene-shRNA transfection group (group P+LPS+shRNA).HPMVECs were transfected with empty plasmid 1.5 μg or with plasmid containing 15 nmol/L β-arrestin-1gene-shRNA.At 24 h of incubation,PHC with the final concentration of 2 μg/ml was added,the cells were incubated for 1 h,LPS with the final concentration of 0.1 μg/ml was then added,and the cells were continuously incubated for another 1 h.The supernatant was collected to measure the activity of lactic dehydrogenase (LDH).The cell suspension was collected for determination of vascular cell adhesion molecule-1 (VCAM-1) expression and NF-κB activities and NF-κB inhibitor I-κB and β-arrestin-1expression.Results Compared with group C,the activities of LDH in supernatant were increased,VCAM-1 expression was up-regulated,NF-κB activity was significantly increased,and I-κB and β-arrestin-1 expression was down-regulated in LPS and LPS+shRNA groups.Compared with group LPS,the activities of LDH in supernatant were decreased,VCAM-1 expression was down-regulated,NF-κB activity was significantly decreased,and I-κB and β-arrestin-l expression was up-regulated in group P+LPS,and no significant change was found in the parameters mentioned above in group P+LPS+shRNA.Compared with group P+LPS,the activities of LDH in supernatant were increased,VCAM-1 expression was up-regulated,NF-κB activity was significantly increased,and I-κB and β-arrestin-1 expression was down-regulated in group P+LPS+shRNA.Conclusion PHC inhibits endotoxin-induced activation of NF-κB in HPMVECs completely through up-regulating β-arrestin-1 expression.