Disruption of calcium homeostasis by cardiac-specific over-expression of PPAR-γ in mice: A role in ventricular arrhythmia.
Life Sci
; 167: 12-21, 2016 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-27746188
ABSTRACT
AIMS:
Adverse cardiovascular effects induced by peroxisome proliferator activator receptor-γ (PPAR-γ) activation were observed in clinical setting. But the underlying mechanism is unclear. Now, transgenic mice with cardiac specific peroxisome proliferator activator receptor-γ overexpression (TG-PPAR-γ) were used to explore the possible mechanisms. MATERIALS ANDMETHODS:
Cardiac tissues from TG-PPAR-γ mice, a PPAR-γ over-expressing human cardiomyocyte line AC16 cell, and PPAR-γ agonist-treated primary cardiomyocytes were used to evaluate the expression of cardiac calcium regulatory proteins as sarcoplasmic reticulum Ca2+ ATPase, Na+/Ca2+ exchanger 1, ryanodine receptor 2 and phospholamban. Intracellular Ca2+ levels were also examined by flow cytometry and confocal microscopy with Fluo-4/AM in these cells. KEYFINDINGS:
In this study, frequent ventricular premature contraction and polymorphic ventricular tachycardia were observed in TG-PPAR-γ but not in wild-type mice. Besides, we found the calcium regulatory proteins expression were higher in the TG-PPAR-γ mice, PPAR-γ overexpressing human cardiomyocyte line AC16 cell and PPAR-γ agonist-treated primary cardiomyocytes than the control group respectively. In addition, an increase of intracellular calcium levels and CaMKII δ expression in PPAR-γ overexpression and PPAR-γ activation group. Moreover, Inhibition of CaMKII δ could improve the intracellular calcium levels and reduce the occurrence of ventricular arrhythmia.SIGNIFICANCE:
PPAR-γ over-expression perturbs the intracellular calcium homeostasis in cardiomyocytes which contribute to the ventricular arrhythmias and cardiac sudden death in TG-PPAR-γ mice.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
6_ODS3_enfermedades_notrasmisibles
Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
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Regulação para Cima
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Cálcio
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Miócitos Cardíacos
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PPAR gama
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Ventrículos do Coração
Limite:
Animals
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Humans
Idioma:
En
Revista:
Life Sci
Ano de publicação:
2016
Tipo de documento:
Article