RESUMO
BACKGROUND: Vascular calcification is common in chronic kidney disease (CKD) and associated with increased cardiovascular mortality. Aldosterone has been implicated as an augmenting factor in the progression of vascular calcification. The present study further explored putative beneficial effects of aldosterone inhibition by the mineralocorticoid receptor antagonist spironolactone on vascular calcification in CKD. METHODS: Serum calcification propensity was determined in serum samples from the MiREnDa trial, a prospective, randomized controlled clinical trial to investigate efficacy and safety of spironolactone in maintenance hemodialysis patients. Experiments were conducted in mice with subtotal nephrectomy and cholecalciferol treatment, and in calcifying primary human aortic smooth muscle cells (HAoSMCs). RESULTS: Serum calcification propensity was improved by spironolactone treatment in patients on hemodialysis from the MiREnDa trial. In mouse models and HAoSMCs, spironolactone treatment ameliorated vascular calcification and expression of osteogenic markers. CONCLUSIONS: These observations support a putative benefit of spironolactone treatment in CKD-associated vascular calcification. Further research is required to investigate possible improvements in cardiovascular outcomes by spironolactone and whether the benefits outweigh the risks in patients with CKD.
Assuntos
Aldosterona/metabolismo , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Diálise Renal , Insuficiência Renal Crônica/tratamento farmacológico , Espironolactona/farmacologia , Calcificação Vascular/tratamento farmacológico , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/patologia , Biomarcadores/metabolismo , Colecalciferol/administração & dosagem , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Feminino , Expressão Gênica , Humanos , Rim/metabolismo , Rim/patologia , Rim/cirurgia , Camundongos , Camundongos Endogâmicos DBA , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Nefrectomia/métodos , Cultura Primária de Células , Estudos Prospectivos , Receptores de Mineralocorticoides/genética , Receptores de Mineralocorticoides/metabolismo , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Fator de Transcrição Pit-1/genética , Fator de Transcrição Pit-1/metabolismo , Calcificação Vascular/genética , Calcificação Vascular/metabolismo , Calcificação Vascular/patologiaRESUMO
Medial vascular calcification, associated with enhanced mortality in chronic kidney disease (CKD), is fostered by osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells (VSMCs). Here, we describe that serum- and glucocorticoid-inducible kinase 1 (SGK1) was upregulated in VSMCs under calcifying conditions. In primary human aortic VSMCs, overexpression of constitutively active SGK1S422D, but not inactive SGK1K127N, upregulated osteo-/chondrogenic marker expression and activity, effects pointing to increased osteo-/chondrogenic transdifferentiation. SGK1S422D induced nuclear translocation and increased transcriptional activity of NF-κB. Silencing or pharmacological inhibition of IKK abrogated the osteoinductive effects of SGK1S422D. Genetic deficiency, silencing, and pharmacological inhibition of SGK1 dissipated phosphate-induced calcification and osteo-/chondrogenic transdifferentiation of VSMCs. Aortic calcification, stiffness, and osteo-/chondrogenic transdifferentiation in mice following cholecalciferol overload were strongly reduced by genetic knockout or pharmacological inhibition of Sgk1 by EMD638683. Similarly, Sgk1 deficiency blunted vascular calcification in apolipoprotein E-deficient mice after subtotal nephrectomy. Treatment of human aortic smooth muscle cells with serum from uremic patients induced osteo-/chondrogenic transdifferentiation, effects ameliorated by EMD638683. These observations identified SGK1 as a key regulator of vascular calcification. SGK1 promoted vascular calcification, at least partly, via NF-κB activation. Inhibition of SGK1 may, thus, reduce the burden of vascular calcification in CKD.
Assuntos
Proteínas Imediatamente Precoces/metabolismo , Miócitos de Músculo Liso/metabolismo , NF-kappa B/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Calcificação Vascular/metabolismo , Animais , Benzamidas/farmacologia , Transdiferenciação Celular/efeitos dos fármacos , Transdiferenciação Celular/genética , Transdiferenciação Celular/fisiologia , Células Cultivadas , Condrogênese/efeitos dos fármacos , Condrogênese/genética , Condrogênese/fisiologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Hidrazinas/farmacologia , Proteínas Imediatamente Precoces/deficiência , Proteínas Imediatamente Precoces/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Knockout para ApoE , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteogênese/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Insuficiência Renal/metabolismo , Insuficiência Renal/patologia , Transdução de Sinais , Calcificação Vascular/etiologia , Calcificação Vascular/patologiaRESUMO
OBJECTIVES: The progression of vascular calcification, an active process promoted by osteo/chondrogenic transformation of vascular smooth muscle cells (VSMCs) is attenuated by activation of the calcium-sensing receptor (CASR). Recent in-vitro studies revealed that vascular calcification could be blunted by Mg, but the underlying mechanisms remained elusive. The present study explored whether the effects of MgCl2 on vascular calcification involve the CASR. METHODS: Experiments were performed in primary human aortic smooth muscle cells (HAoSMCs) and in the mouse vascular calcification model of vitamin D3 overload. RESULTS: Phosphate-induced calcium deposition and mRNA expression of the osteogenic markers msh homeobox 2 (MSX2), CBFA1 (core-binding factor α 1), and ALPL (tissue-nonspecific alkaline phosphatase) in HAoSMCs were blunted by additional treatment with MgCl2. MgCl2 upregulated CASR mRNA expression in HAoSMCs in a dose-dependent manner. Furthermore, the inhibitory effects of MgCl2 on phosphate-induced calcium deposition and osteogenic markers mRNA expression were mimicked by the CASR agonist GdCl3 and reversed by additional treatment with the CASR antagonist NPS-2143 or by silencing of the CASR gene in HAoSMCs. MgCl2 also blunted the osteogenic transformation of VSMCs induced by hydroxyapatite particles. High-dosed cholecalciferol treatment induced vascular calcification and upregulated aortic osteogenic markers Msx2, Cbfa1 and Alpl and collagen type I (Col1a1), collagen type III (Col3a1) and fibronectin (Fbn) mRNA expression in mice, effects reduced by additional treatment with MgCl2. These effects were paralleled by increased aortic Casr mRNA expression in cholecalciferol-treated mice, which was further augmented by MgCl2. CONCLUSION: The protective effects of MgCl2 on osteo/chondrogenic transformation of VSMCs and vascular calcification involve regulation of CASR and CASR-dependent signaling.