title: Cross talk between NADPH oxidase and autophagy in pulmonary artery endothelial cells with intrauterine persistent pulmonary hypertension.
abstract: Autophagy is a process for cells to degrade proteins or entire organelles to maintain a balance in the synthesis, degradation, and subsequent recycling of cellular products. Increased reactive oxygen species formation is known to induce autophagy. We previously reported that increased NADPH oxidase (NOX) activity in pulmonary artery endothelial cells (PAEC) from fetal lambs with persistent pulmonary hypertension (PPHN) contributes to impaired angiogenesis in PPHN-PAEC compared with normal PAEC. We hypothesized that increased NOX activity in PPHN-PAEC is associated with increased autophagy, which, in turn, contributes to impaired angiogenesis in PPHN-PAEC. In the present study, we detected increased autophagy in PPHN-PAEC as shown by increased ratio of the microtubule-associated protein 1 light chain (LC3)-II to LC3-I and increased percentage of green fluorescent protein-LC3 punctate positive cells. Inhibiting autophagy by 3-methyladenine, chloroquine, and beclin-1 knockdown in PPHN-PAEC has led to decreased autophagy and increased in vitro angiogenesis. Inhibition of autophagy also decreased the association between gp91(phox) and p47(phox), NOX activity, and superoxide generation. A nonspecific antioxidant N-acetylcysteine and a NOX inhibitor apocynin decreased autophagy in PPHN-PAEC. In conclusion, autophagy may contribute to impaired angiogenesis in PPHN-PAEC through increasing NOX activity. Our results suggest that, in PPHN-PAEC, a positive feedback relationship between autophagy and NOX activity may regulate angiogenesis.
authors.affiliation: Div. of Neonatology, Dept. of Pediatrics, Medical College of Wisconsin, Wauwatosa, WI 53226, USA. rteng@mcw.edu
authors.forename: Ru-Jeng
authors.initials: RJ
authors.lastname: Teng
authors.forename: Jianhai
authors.initials: J
authors.lastname: Du
authors.forename: Scott
authors.initials: S
authors.lastname: Welak
authors.forename: Tongju
authors.initials: T
authors.lastname: Guan
authors.forename: Annie
authors.initials: A
authors.lastname: Eis
authors.forename: Yang
authors.initials: Y
authors.lastname: Shi
authors.forename: Girija G
authors.initials: GG
authors.lastname: Konduri
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000172:deficiency / Q000235:genetics; D001343:Autophagy / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002738:Chloroquine / Q000494:pharmacology; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000503:physiopathology; D049452:Green Fluorescent Proteins / Q000235:genetics; D006976:Hypertension, Pulmonary / Q000378:metabolism* / Q000503:physiopathology; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology; D009687:Nuclear Proteins / Q000378:metabolism; D011651:Pulmonary Artery / Q000378:metabolism* / Q000503:physiopathology; D017382:Reactive Oxygen Species / Q000097:blood; D011971:Receptors, Immunologic / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012756:Sheep
chemical_list: D051017:Apoptosis Regulatory Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D017382:Reactive Oxygen Species; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C025946:3-methyladenine; D002738:Chloroquine; D019255:NADPH Oxidases; D000225:Adenine