title: Peroxisome Proliferator-Activated Receptor γ and microRNA 98 in Hypoxia-Induced Endothelin-1 Signaling.
abstract: Endothelin-1 (ET-1) plays a critical role in endothelial dysfunction and contributes to the pathogenesis of pulmonary hypertension (PH). We hypothesized that peroxisome proliferator-activated receptor γ (PPARγ) stimulates microRNAs that inhibit ET-1 and pulmonary artery endothelial cell (PAEC) proliferation. The objective of this study was to clarify molecular mechanisms by which PPARγ regulates ET-1 expression in vitro and in vivo. In PAECs isolated from patients with pulmonary arterial hypertension, microRNA (miR)-98 expression was reduced, and ET-1 protein levels and proliferation were increased. Similarly, hypoxia reduced miR-98 and increased ET-1 levels and PAEC proliferation in vitro. In vivo, hypoxia reduced miR-98 expression and increased ET-1 and proliferating cell nuclear antigen (PCNA) levels in mouse lung, derangements that were aggravated by treatment with the vascular endothelial growth factor receptor antagonist Sugen5416. Reporter assays confirmed that miR-98 binds directly to the ET-1 3'-untranslated region. Compared with littermate control mice, miR-98 levels were reduced and ET-1 and PCNA expression were increased in lungs from endothelial-targeted PPARγ knockout mice, whereas miR-98 levels were increased and ET-1 and PCNA expression was reduced in lungs from endothelial-targeted PPARγ-overexpression mice. Gain or loss of PPARγ function in PAECs in vitro confirmed that alterations in PPARγ were sufficient to regulate miR-98, ET-1, and PCNA expression. Finally, PPARγ activation with rosiglitazone regimens that attenuated hypoxia-induced PH in vivo and human PAEC proliferation in vitro restored miR-98 levels. The results of this study show that PPARγ regulates miR-98 to modulate ET-1 expression and PAEC proliferation. These results further clarify molecular mechanisms by which PPARγ participates in PH pathogenesis and therapy.
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Bum-Yong
authors.identifier: http://orcid.org/0000-0001-8251-1637
authors.initials: BY
authors.lastname: Kang
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Kathy K
authors.initials: KK
authors.lastname: Park
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Kleinhenz
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Tamara C
authors.initials: TC
authors.lastname: Murphy
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: David E
authors.initials: DE
authors.lastname: Green
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Kaiser M
authors.initials: KM
authors.lastname: Bijli
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Yeligar
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Kristal A
authors.initials: KA
authors.lastname: Carthan
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Searles
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: Roy L
authors.initials: RL
authors.lastname: Sutliff
authors.affiliation: Department of Medicine, Atlanta Veterans Affairs, and Emory University Medical Centers, Atlanta, Georgia.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Hart
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001665:Binding Sites; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000860:Hypoxia / Q000150:complications / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D007211:Indoles; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D047495:PPAR gamma / Q000819:agonists / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011651:Pulmonary Artery / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D011758:Pyrroles; D034622:RNA Interference; D000077154:Rosiglitazone; D015398:Signal Transduction / Q000187:drug effects; D045162:Thiazolidinediones / Q000494:pharmacology; D014162:Transfection; D066253:Vascular Remodeling
chemical_list: D020413:3' Untranslated Regions; D019332:Endothelin-1; D007211:Indoles; C546084:MIRN98 microRNA, human; C557404:MIRN98 microRNA, mouse; D035683:MicroRNAs; D047495:PPAR gamma; D011758:Pyrroles; D045162:Thiazolidinediones; D000077154:Rosiglitazone; C116890:Semaxinib
keywords: ET-1; PPARγ; hypoxia; miR-98; pulmonary hypertension