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
Background The high cardiovascular morbidity and mortality of patients with CKD may result in large part from medial vascular calcification, a process promoted by hyperphosphatemia and involving osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells (VSMCs). Reduced serum zinc levels have frequently been observed in patients with CKD, but the functional relevance of this remains unclear.Methods We performed experiments in primary human aortic VSMCs; klotho-hypomorphic (kl/kl), subtotal nephrectomy, and cholecalciferol-overload mouse calcification models; and serum samples from patients with CKD.Results In cultured VSMCs, treatment with zinc sulfate (ZnSO4) blunted phosphate-induced calcification, osteo-/chondrogenic signaling, and NF-κB activation. ZnSO4 increased the abundance of zinc-finger protein TNF-α-induced protein 3 (TNFAIP3, also known as A20), a suppressor of the NF-κB pathway, by zinc-sensing receptor ZnR/GPR39-dependent upregulation of TNFAIP3 gene expression. Silencing of TNFAIP3 in VSMCs blunted the anticalcific effects of ZnSO4 under high phosphate conditions. kl/kl mice showed reduced plasma zinc levels, and ZnSO4 supplementation strongly blunted vascular calcification and aortic osteoinduction and upregulated aortic Tnfaip3 expression. ZnSO4 ameliorated vascular calcification in mice with chronic renal failure and mice with cholecalciferol overload. In patients with CKD, serum zinc concentrations inversely correlated with serum calcification propensity. Finally, ZnSO4 ameliorated the osteoinductive effects of uremic serum in VSMCs.Conclusions Zinc supplementation ameliorates phosphate-induced osteo-/chondrogenic transdifferentiation of VSMCs and vascular calcification through an active cellular mechanism resulting from GPR39-dependent induction of TNFAIP3 and subsequent suppression of the NF-κB pathway. Zinc supplementation may be a simple treatment to reduce the burden of vascular calcification in CKD.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Falência Renal Crônica/sangue , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/fisiologia , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Calcificação Vascular/prevenção & controle , Sulfato de Zinco/farmacologia , Animais , Aorta , Transdiferenciação Celular , Células Cultivadas , Suplementos Nutricionais , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Glucuronidase/genética , Humanos , Hidroxietilrutosídeo , Hiperfosfatemia/sangue , Hiperfosfatemia/complicações , Proteínas Klotho , Camundongos , NF-kappa B/antagonistas & inibidores , Nefrectomia , Nefrocalcinose/prevenção & controle , Fosfatos , Transdução de Sinais , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Calcificação Vascular/sangue , Calcificação Vascular/etiologia , Zinco/sangueRESUMO
AIMS: Uromodulin is produced exclusively in the kidney and secreted into both urine and blood. Serum levels of uromodulin are correlated with kidney function and reduced in chronic kidney disease (CKD) patients, but physiological functions of serum uromodulin are still elusive. This study investigated the role of uromodulin in medial vascular calcification, a key factor associated with cardiovascular events and mortality in CKD patients. METHODS AND RESULTS: Experiments were performed in primary human (HAoSMCs) and mouse (MOVAS) aortic smooth muscle cells, cholecalciferol overload and subtotal nephrectomy mouse models and serum from CKD patients. In three independent cohorts of CKD patients, serum uromodulin concentrations were inversely correlated with serum calcification propensity. Uromodulin supplementation reduced phosphate-induced osteo-/chondrogenic transdifferentiation and calcification of HAoSMCs. In human serum, pro-inflammatory cytokines tumour necrosis factor α (TNFα) and interleukin-1ß (IL-1ß) co-immunoprecipitated with uromodulin. Uromodulin inhibited TNFα and IL-1ß-induced osteo-/chondrogenic signalling and activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated ß cells (NF-kB) as well as phosphate-induced NF-kB-dependent transcriptional activity in HAoSMCs. In vivo, adeno-associated virus (AAV)-mediated overexpression of uromodulin ameliorated vascular calcification in mice with cholecalciferol overload. Conversely, cholecalciferol overload-induced vascular calcification was aggravated in uromodulin-deficient mice. In contrast, uromodulin overexpression failed to reduce vascular calcification during renal failure in mice. Carbamylated uromodulin was detected in serum of CKD patients and uromodulin carbamylation inhibited its anti-calcific properties in vitro. CONCLUSIONS: Uromodulin counteracts vascular osteo-/chondrogenic transdifferentiation and calcification, at least in part, through interference with cytokine-dependent pro-calcific signalling. In CKD, reduction and carbamylation of uromodulin may contribute to vascular pathology.
Assuntos
Transdiferenciação Celular , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Insuficiência Renal Crônica/sangue , Uromodulina/sangue , Calcificação Vascular/prevenção & controle , Adulto , Idoso , Animais , Aorta/imunologia , Aorta/metabolismo , Transdiferenciação Celular/efeitos dos fármacos , Células Cultivadas , Condrogênese , Citocinas/genética , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Pessoa de Meia-Idade , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/imunologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/imunologia , Osteogênese , Fenótipo , Carbamilação de Proteínas , Insuficiência Renal Crônica/imunologia , Transdução de Sinais , Uromodulina/genética , Uromodulina/farmacologia , Calcificação Vascular/sangue , Calcificação Vascular/imunologia , Adulto JovemRESUMO
Medial vascular calcification occurs during the aging process and is strongly accelerated by chronic kidney disease (CKD). Elevated C-reactive protein (CRP) levels are associated with vascular calcification, cardiovascular events and mortality in CKD patients. CRP is an important promoter of vascular inflammation. Inflammatory processes are critically involved in initiation and progression of vascular calcification. Thus, the present study explored a possible impact of CRP on vascular calcification. We found that CRP promoted osteo-/chondrogenic transdifferentiation and aggravated phosphate-induced osteo-/chondrogenic transdifferentiation and calcification of primary human aortic smooth muscle cells (HAoSMCs). These effects were paralleled by increased cellular oxidative stress and corresponding pro-calcific downstream-signaling. Antioxidants or p38 MAPK inhibition suppressed CRP-induced osteo-/chondrogenic signaling and mineralization. Furthermore, silencing of Fc fragment of IgG receptor IIa (FCGR2A) blunted the pro-calcific effects of CRP. Vascular CRP expression was increased in the klotho-hypomorphic mouse model of aging as well as in HAoSMCs during calcifying conditions. In conclusion, CRP augments osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells through mechanisms involving FCGR2A-dependent induction of oxidative stress. Thus, systemic inflammation may actively contribute to the progression of vascular calcification.