title: Rosiglitazone attenuates hypoxia-induced pulmonary arterial remodeling.
abstract: Thiazolidinediones (TZDs) are insulin-sensitizing agents that also decrease systemic blood pressure, attenuate the formation of atherosclerotic lesions, and block remodeling of injured arterial walls. Recently, TZDs were shown to prevent pulmonary arterial (PA) remodeling in rats treated with monocrotaline. Presently we report studies testing the ability of the TZD rosiglitazone (ROSI) to attenuate pathological arterial remodeling in the lung and prevent the development of pulmonary hypertension (PH) in rats subjected to chronic hypoxia. PA remodeling was reduced in ROSI-treated animals exposed to hypoxia compared with animals exposed to hypoxia alone. ROSI treatment blocked muscularization of distal pulmonary arterioles and reversed remodeling and neomuscularization in lungs of animals previously exposed to chronic hypoxia. Decreased PA remodeling in ROSI-treated animals was associated with decreased smooth muscle cell proliferation, decreased collagen and elastin deposition, and increased matrix metalloproteinase-2 activity in the PA wall. Cells expressing the c-Kit cell surface marker were observed in the PA adventitia of untreated animals exposed to hypoxia but not in ROSI-treated hypoxic rats. Right ventricular hypertrophy and cardiomyocyte hypertrophy were also blunted in ROSI-treated hypoxic animals. Interestingly, mean PA pressures were elevated equally in the untreated and ROSI-treated groups, indicating that ROSI had no effect on the development of PH. However, mean PA pressure was normalized acutely in both groups of hypoxia-exposed animals by Fasudil, an agent that inhibits RhoA/Rho kinase-mediated vasoconstriction. We conclude that ROSI can attenuate and reverse PA remodeling and neomuscularization associated with hypoxic PH. However, this agent fails to block the development of PH, apparently because of its inability to repress sustained Rho kinase-mediated arterial vasoconstriction.
authors.affiliation: Pulmonary and Critical Care Services, Veterans Affairs Medical Center, Denver, USA.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Crossno
authors.forename: Chrystelle V
authors.initials: CV
authors.lastname: Garat
authors.forename: Jane E B
authors.initials: JE
authors.lastname: Reusch
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Morris
authors.forename: Edward C
authors.initials: EC
authors.lastname: Dempsey
authors.forename: Ivan F
authors.initials: IF
authors.lastname: McMurtry
authors.forename: Kurt R
authors.initials: KR
authors.lastname: Stenmark
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Klemm
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D004549:Elastin / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D017380:Hypertrophy, Right Ventricular / Q000188:drug therapy; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D047495:PPAR gamma / Q000819:agonists; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011921:Rats, Inbred WKY; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000627:therapeutic use*
chemical_list: D047495:PPAR gamma; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D003094:Collagen; D004549:Elastin; D019009:Proto-Oncogene Proteins c-kit