Reactive oxygen species mediate shear stress-induced fluid-phase endocytosis in vascular endothelial cells.
To elucidate the role of shear stress in fluid-phase endocytosis of vascular endothelial cells (EC), we used a rotating-disk shearing apparatus to investigate the effects of shear stress on the uptake of lucifer yellow (LY) by cultured bovine aortic endothelial cells (BAEC). Exposure of EC to shear stress (area-mean value of 10 dynes/cm2) caused an increase in LY uptake that was abrogated by the antioxidant, N-acetyl-L-cysteine (NAC), the NADPH oxidase inhibitor, acetovanillone, and two inhibitors of protein kinase C (PKC), calphostin C and GF109203X. These results suggest that fluid-phase endocytosis is regulated by both reactive oxygen species (ROS) and PKC. Shear stress increased both ROS production and PKC activity in EC, and the increase in ROS was unaffected by calphostin C or GF109203X, whereas the activation of PKC was reduced by NAC and acetovanillone. We conclude that shear stress-induced increase in fluid-phase endocytosis is mediated via ROS generation followed by PKC activation in EC.
Niwa
Koichi
K
Faculty of Bioindustry, Tokyo University of Agriculture, Department of Food Science and Technology, 196 Yasaka, Abashiri, 099-2493, Japan. k3niwa@bioindustry.nodai.ac.jp
Sakai
Jiro
J
Karino
Takeshi
T
Aonuma
Hitoshi
H
Watanabe
Toshihiro
T
Ohyama
Tohru
T
Inanami
Osamu
O
Kuwabara
Mikinori
M
D000098:Acetophenones / Q000494:pharmacology; D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001011:Aorta; D002417:Cattle; D004705:Endocytosis; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D047468:Immunoprecipitation; D007211:Indoles / Q000494:pharmacology; D007546:Isoquinolines; D008301:Maleimides / Q000494:pharmacology; D008560:Membrane Fluidity; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D009281:Naphthalenes / Q000494:pharmacology; D044367:Phase Transition; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D017382:Reactive Oxygen Species / Q000378:metabolism*; D033081:Shear Strength; D012996:Solutions; D013314:Stress, Mechanical
D000098:Acetophenones; D000975:Antioxidants; D004791:Enzyme Inhibitors; D007211:Indoles; D007546:Isoquinolines; D008301:Maleimides; D009281:Naphthalenes; D017382:Reactive Oxygen Species; D012996:Solutions; C017475:lucifer yellow; C056165:acetovanillone; D019255:NADPH Oxidases; D011493:Protein Kinase C; C058819:calphostin C; C070515:bisindolylmaleimide I; D000111:Acetylcysteine