Expression Of Nrf2 In Human Pulmonary Artery Smooth Cells Exposed To Cigarette Smoke Extract And The Possible Mechanism With Senescence

I.Background The oxidative stress induced by long-term smoking is an important cause of the disease chronic obstructive pulmonary disease(COPD).Pulmonary hypertension and pulmonary vascular remodeling are important complications of COPD,and their basic pathological changes include the aging of pulmonary artery smooth muscle cells(PASMCs)and fibroblasts,as well as the proliferation and migration of pulmonary artery smooth muscle cells.Transcription factor nuclear factors 2(Nrf2)is an important antioxidant,playing a critical role in antioxidant system.Resveratrol,a polyphenolic phytoalexin,has been reported to have antioxidant,anti-inflammatory,anticarcinogenic capability,also has antioxidant signaling properties via the activation of Nrf2 and protects lung injury against cigarette smoke extract(CSE)-mediated oxidative stress.At present the mechanism about resveratrol and Nrf2 in CSE-induced pulmonary arterial smooth muscle cells aging is still unclear.II.Objective This study was designed to investigate the role of Nrf2 and its related proteins in the process of CSE-induced HPASMCs aging,the possible mechanism of antagonist resveratrol usage in the process.It may provide a new clinical therapy strategy and laborotary evidence of COPD.III.Methods HPASMCs were treated in a long-term CSE exposure condition,and we used Real-time PCR ?Western blot to detect the expressions related proteins in HPASMCs,and detected the proliferation viability of HPASMCs using CCK-8.We also examined cell telomere length by FLOW-FISH.Flowcytometry analysis was used to detect cell cycle and according to the SA-?-gal staining Kit,SA-?-gal staining was performed.Finally,we detected the changes of proliferation and migration of PASMCs by Brd U immunofluorescence and transwell migration assay respectively.IV.Results After a long-term CSE exposure,some changes of HPASMCs has occurred.With the increase of CSE concentrations the expression of Nrf2 and its related proteins was upregulated at first and then inhibited,and the main change is Nrf2 recruiting in the nucleus of a cell.The expression of Nrf2 significantly increased with the pretreatment of resveratrol,and the proteins related with cell aging expression downregulation.When silencing Nrf2,there would be significantly premature senescent change of HPASMCs.The stimulation of conditioned medium enhanced normal pulmonary artery smooth muscle cells proliferation and migration.V.Conclusions The expression of Nrf2 is downregulation after long-time of cigarette smoke stimulation in pulmonary artery smooth muscle cells,and induced aging of the cells.Resveratrol activates the expression of Nrf2 and protects against cigarette smoke extract(CSE)-mediated lung injury.After transformation of senescence-related secretory phenotype(SASP)in aging cells,SASP could stimulate those unsenescent smooth muscle cells proliferation and migration to promote the pulmonary vascular remodeling.