title: Hypoxia-inducible factor-1 plays a role in phosphate-induced vascular smooth muscle cell calcification.
abstract: Medial vascular calcification is a common complication of chronic kidney disease (CKD). Although elevated inorganic phosphate stimulates vascular smooth muscle cell (VSMC) osteogenic transdifferentiation and calcification, the mechanisms involved in their calcification during CKD are not fully defined. Because hypoxic gene activation is linked to CKD and stimulates bone cell osteogenic differentiation, we used in vivo and in vitro rodent models to define the role of hypoxic signaling during elevated inorganic phosphate-induced VSMC calcification. Cell mineralization studies showed that elevated inorganic phosphate rapidly induced VSMC calcification. Hypoxia strongly enhanced elevated inorganic phosphate-induced VSMC calcification and osteogenic transdifferentiation, as seen by osteogenic marker expression. Hypoxia-inducible factor-1 (HIF-1), the key hypoxic transcription factor, was essential for enhanced VSMC calcification. Targeting HIF-1 expression in murine VSMC blocked calcification in hypoxia with elevated inorganic phosphate while HIF-1 activators, including clinically used FG-4592/Roxadustat, recreated a procalcifying environment. Elevated inorganic phosphate rapidly activated HIF-1, even in normal oxygenation; an effect mediated by HIF-1α subunit stabilization. Thus, hypoxia synergizes with elevated inorganic phosphate to enhance VSMC osteogenic transdifferentiation. Our work identifies HIF-1 as an early CKD-related pathological event, prospective marker, and potential target against vascular calcification in CKD-relevant conditions.
authors.affiliation: Department of Molecular Biology, Medical Biochemistry, and Pathology, Centre de recherche du CHU de Québec, Université Laval, Québec, Québec, Canada.
authors.forename: Sophie
authors.initials: S
authors.lastname: Mokas
authors.affiliation: Department of Medicine, Centre de recherche du CHU de Québec, Université Laval, Québec, Québec, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Larivière
authors.affiliation: Department of Molecular Biology, Medical Biochemistry, and Pathology, Centre de recherche du CHU de Québec, Université Laval, Québec, Québec, Canada.
authors.forename: Laurent
authors.initials: L
authors.lastname: Lamalice
authors.affiliation: Department of Molecular Medicine, Centre de recherche du CHU de Québec, Université Laval, Québec, Québec, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Gobeil
authors.affiliation: Center for Excellence in Pulmonary Biology, Stanford University, Stanford, California, USA.
authors.forename: David N
authors.initials: DN
authors.lastname: Cornfield
authors.affiliation: Department of Medicine, Centre de recherche du CHU de Québec, Université Laval, Québec, Québec, Canada.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Agharazii
authors.affiliation: Department of Molecular Biology, Medical Biochemistry, and Pathology, Centre de recherche du CHU de Québec, Université Laval, Québec, Québec, Canada. Electronic address: darren.richard@crchudequebec.ulaval.ca.
authors.forename: Darren E
authors.initials: DE
authors.lastname: Richard
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D054338:Cell Transdifferentiation; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D007150:Immunohistochemistry; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D010710:Phosphates / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000378:metabolism; D015398:Signal Transduction; D061205:Vascular Calcification / Q000209:etiology / Q000378:metabolism*; D059289:Vascular Stiffness
chemical_list: D015415:Biomarkers; C497444:Hif1a protein, rat; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007546:Isoquinolines; D010710:Phosphates; D005998:Glycine; C584543:roxadustat
keywords: HIF-1; chronic kidney disease; hypoxia; mineral imbalance; vascular calcification