Hypoxia-induced pulmonary vascular adventitia fibroblast proliferation requires JNK –mediated Elk-1–dependent expression of 15-lipoxygenase

【作者】 朱大岭； 王晓艳； 张莉； 陈明刚； 刘玉梅； 邢妍；

【机构】 哈尔滨医科大学大庆校区；

【摘要】 Background–15-lipoxygenase(15-LO)induced vascular adventitia fibrosis,while its effect on pulmonary adventitial fibroblast(PAF)proliferation was unclear.The aim of the present study was intent to exploit the roles of 15-LO in modulation of PAF proliferation,and further reveal the potential mechanisms.MethodsQuantitative RT-PCR and Western blot analysis were used to determine 15-LO expression in PAFs.The role of JNK in 15-LO–induced PAF proliferation was measured using MTT,cell immunofluorescence,Flow cytometry,and Western blot.Results-Hypoxia induced the increase of 15-LO expression.15-HETE stimulated PAF proliferation and cell cycle alteration.In addition,hypoxia stimulated the phosphorylation of JNK in a time-dependent manner in these cells.Blockade of JNK suppressed 15-LO–in duced PAF proliferation and cell cycle change.Inhibition of p27kipl by gene silencing approach attenuated15-LO–induced cell proliferation and cell cycle alteration.Furthermore,hypoxia activated TGF-β1 kinase,and knockdown TGF-β1 inhibited JNK phosphorylation.Inhibition of JNK or knockdown Elk-1 also suppressed hypoxia-induced 15-LO expression in PAFs.Conclusion-These results suggest that hypoxia leads to cell proliferation through the induction of 15-LO expression in PAFs.15-LO modulating p27kipl expression promotes PAF proliferation and cell cycle alteration.In addition,hypoxia,through JNK-dependent a boost in Elk-1,stimulates 15-LO expression in PAFs.更多还原

【Abstract】 Background – 15-lipoxygenase(15-LO) induced vascular adventitia fibrosis,while its effect on pulmonary adventitial fibroblast(PAF) proliferation was unclear.The aim of the present study was intent to exploit the roles of 15-LO in modulation of PAF proliferation,and further reveal the potential mechanisms.Methods-Quantitative RT-PCR and Western blot analysis were used to determine 15-LO expression in PAFs.The role of JNK in 15-LO–induced PAF proliferation was measured using MTT,cell immunofluorescence,Flow cytometry,and Western blot.Results-Hypoxia induced the increase of 15-LO expression.15-HETE stimulated PAF proliferation and cell cycle alteration.In addition,hypoxia stimulated the phosphorylation of JNK in a time-dependent manner in these cells.Blockade of JNK suppressed 15-LO–in duced PAF proliferation and cell cycle change.Inhibition of p27 kipl by gene silencing approach attenuated 15-LO–induced cell proliferation and cell cycle alteration.Furthermore,hypoxia activated TGF-β1 kinase,and knockdown TGF-β1 inhibited JNK phosphorylation.Inhibition of JNK or knockdown Elk-1 also suppressed hypoxia-induced 15-LO expression in PAFs.Conclusion-These results suggest that hypoxia leads to cell proliferation through the induction of 15-LO expression in PAFs.15-LO modulating p27 kipl expression promotes PAF proliferation and cell cycle alteration.In addition,hypoxia,through JNK-dependent a boost in Elk-1,stimulates 15-LO expression in PAFs.更多还原