title: Microtubule-active agents modify nitric oxide production in pulmonary artery endothelial cells.
abstract: The effects of specific microtubule-active agents on nitric oxide (NO) production were examined in pulmonary artery endothelial cells (PAEC). PAEC were incubated with taxol, which stabilizes microtubules, or nocodazole, which disrupts microtubules, or both for 2-4 h. We then examined NO production, endothelial NO synthase (eNOS) activity, and eNOS association with heat shock protein (HSP) 90. Incubation of PAEC with taxol (15 microM) for 2-4 h resulted in an increase in NO production, eNOS activity, and the amount of HSP90 binding to eNOS. Incubation of PAEC with nocodazole (50 microM) for 2-4 h induced a decrease in NO production, eNOS activity, and the amount of HSP90 binding to eNOS. The presence of taxol in the culture medium prevented the effects of nocodazole on NO production and eNOS activity in PAEC. Geldanamycin, a HSP90 inhibitor, prevented the taxol-induced increase in eNOS activity. Taxol and nocodazole did not affect eNOS, HSP90, and tubulin protein contents in PAEC, as detected using Western blot analysis. These results indicate that the polymerization state of the microtubule cytoskeleton regulates NO production and eNOS activity in PAEC. The changes in eNOS activity induced by modification of microtubules are due, at least in part, to the altered binding of HSP90 to eNOS protein.
authors: Department of Medicine, University of Florida College of Medicine, Gainesville 32608-1197, USA. ysu@ufl.edu
authors: Yunchao
authors: Y
authors: Su
authors: Sergei I
authors: SI
authors: Zharikov
authors: Edward R
authors: ER
authors: Block
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D016227:Benzoquinones; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D002478:Cells, Cultured; D002956:Citrulline / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D047029:Lactams, Macrocyclic; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D015739:Nocodazole / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology; D011233:Precipitin Tests; D011485:Protein Binding / Q000502:physiology; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011809:Quinones / Q000494:pharmacology; D013552:Swine
chemical_list: D000970:Antineoplastic Agents; D016227:Benzoquinones; D004791:Enzyme Inhibitors; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D011809:Quinones; D002956:Citrulline; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D017239:Paclitaxel; D015739:Nocodazole; C001277:geldanamycin