Angiotensin II prevents calcification in vascular smooth muscle cells by enhancing magnesium influx.
BACKGROUND
Vascular calcification (VC) is highly prevalent in patients with chronic kidney disease (CKD). Low magnesium levels are associated with VC, and recent in vitro studies confirm a protective role of magnesium, which is mediated by its entry into the VSMCs through the Transient Receptor Potential Melastatin 7 (TRPM7) channel. The role of Angiotensin II (Ang II) on VC is still unclear. As Ang II is able to stimulate TRPM7 activity, we hypothesize that it might prevent VC. Thus, the aim of this study was to dissect the direct effect of Ang II on VC.


METHODS
We worked with a model of high phosphate (HP)-induced calcification in human aortic smooth muscle cells, which resembles the CKD-related VC.


RESULTS
Addition of Ang II to cells growing in HP decreased calcification, which was associated with the upregulation of the osteogenic factors BMP2, Runx2/Cbfa1, Osterix and ALP. A reduction of magnesium entry into the HP-calcifying cells was found. The treatment with Ang II avoided this reduction, which was reversed by the cotreatment with the TRPM7-inhibitor 2-APB. The protective effect of Ang II was related to AT1R-induced ERK1/2 MAPKinase activation. HP-induced calcification was also associated with the upregulation of the canonical Wnt/beta-catenin pathway, while its downregulation was related to attenuation of calcification by Ang II.


CONCLUSIONS
As hypothesized, Ang II prevented phosphate-induced calcification in VSMCs, which appears mediated by the increase of magnesium influx and by the activation of the ERK1/2 and the inhibition of the canonical Wnt/beta-catenin signalling pathways.
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Carmen
C
Herencia
Laboratory of Nephrology, IIS-Fundación Jiménez Diaz, Madrid, Spain.|REDinREN, Madrid, Spain.
M Encarnacion
ME
Rodríguez-Ortiz
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Juan R
JR
Muñoz-Castañeda
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Julio Manuel
JM
Martinez-Moreno
Department of Environmental Biology and Public Health, University of Huelva, Huelva, Spain.
Rocío
R
Canalejo
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Addy
A
Montes de Oca
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Juan M
JM
Díaz-Tocados
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Esther
E
Peralbo-Santaella
Lipid and Atherosclerosis Unit, IMIBIC/Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.|CIBER Fisiopatologia Obesidad y Nutricion (CIBEROBN), Instituto de Salud Carlos III, Cordoba, Spain.
Carmen
C
Marín
Department of Environmental Biology and Public Health, University of Huelva, Huelva, Spain.
Antonio
A
Canalejo
REDinREN, Madrid, Spain.|Nefrology Service, Instituto Maimonides de Investigacion Biomédica de Córdoba (IMIBIC), Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.
Mariano
M
Rodriguez
Lipid and Atherosclerosis Unit, IMIBIC/Reina Sofia University Hospital/University of Cordoba, Cordoba, Spain.|CIBER Fisiopatologia Obesidad y Nutricion (CIBEROBN), Instituto de Salud Carlos III, Cordoba, Spain.
Yolanda
Y
Almaden
D000469:Alkaline Phosphatase / Q000187:drug effects / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology*; D055396:Bone Morphogenetic Protein 2 / Q000187:drug effects / Q000378:metabolism; D001896:Boron Compounds / Q000494:pharmacology; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008274:Magnesium / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000378:metabolism; D000076182:Sp7 Transcription Factor; D050053:TRPM Cation Channels / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000378:metabolism; D014157:Transcription Factors / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation; D061205:Vascular Calcification / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D060449:Wnt Signaling Pathway / Q000187:drug effects
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D001896:Boron Compounds; D050659:Core Binding Factor Alpha 1 Subunit; C493709:RUNX2 protein, human; D000076182:Sp7 Transcription Factor; C478163:SP7 protein, human; D050053:TRPM Cation Channels; D014157:Transcription Factors; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; C109986:2-aminoethoxydiphenyl borate; D017346:Protein Serine-Threonine Kinases; C486583:TRPM7 protein, human; D000469:Alkaline Phosphatase; D008274:Magnesium
Wnt/beta-catenin; angiotensin II; chronic kidney disease; magnesium; transient receptor potential melastatin 7; vascular calcification