Alpha-skeletal muscle actin mRNA's accumulate in hypertrophied adult rat hearts.

Schwartz, Ketty; Bastie, D. de la; Bouveret, P.; Oliviéro, P.; Alonso, Serge; Buckingham, M

doi:10.1161/01.res.59.5.551

Cited by 275 publications

(134 citation statements)

References 25 publications

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“…The increases in the expression levels of: (a) calreticulin, which has also been reported to increase in pressure overload hypertrophy (42) In the calsequestrin overexpressing heart as well as a variety of other experimental models, cardiac hypertrophy was associated with increased expression of fetal genes (23,(43)(44)(45). Interestingly, the up-regulation of ␣-skeletal actin and ANF mRNA was reversed by phospholamban ablation.…”

Section: Discussionmentioning

confidence: 93%

Rescue of Contractile Parameters and Myocyte Hypertrophy in Calsequestrin Overexpressing Myocardium by Phospholamban Ablation

Sato

Kiriazis²,

Yatani³

et al. 2001

Journal of Biological Chemistry

103

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Cardiac-specific overexpression of murine cardiac calsequestrin results in depressed cardiac contractile parameters, low Ca 2؉ -induced Ca 2؉ release from sarcoplasmic reticulum (SR) and cardiac hypertrophy in transgenic mice. To test the hypothesis that inhibition of phospholamban activity may rescue some of these phenotypic alterations, the calsequestrin overexpressing mice were cross-bred with phospholamban-knockout mice. Phospholamban ablation in calsequestrin overexpressing mice led to reversal of the depressed cardiac contractile parameters in Langendorff-perfused hearts or in vivo. This was associated with increases of SR Ca 2؉ storage, assessed by caffeine-induced Na ؉ -Ca 2؉ exchanger currents. The inactivation time of the L-type Ca 2؉ current (I Ca ), which has an inverse correlation with Ca 2؉ -induced SR Ca 2؉ release, and the relation between the peak current density and half-inactivation time were also normalized, indicating a restoration in the ability of I Ca to trigger SR Ca 2؉ release. The prolonged action potentials in calsequestrin overexpressing cardiomyocytes also reversed to normal upon phospholamban ablation. Furthermore, ablation of phospholamban restored the expression levels of atrial natriuretic factor and ␣-skeletal actin mRNA as well as ventricular myocyte size. These results indicate that attenuation of phospholamban function may prevent or overcome functional and remodeling defects in hypertrophied hearts.Hypertrophy of ventricular myocardium is postulated to be an adaptive response to relative increases in external workload, induced by endocrine, paracrine, autocrine, and mechanical factors or decreased myocardial contractility (1). The increase in heart mass has been implicated to normalize cardiac function by decreasing wall stress. However, a sustained imbalance between workload and muscle contractility may lead to progressive thinning of the left ventricular wall and chamber dilation associated with decompensated hypertrophy and heart failure (2, 3). Studies in human and animal models have shown that cardiac hypertrophy is associated with impaired sarcoplasmic reticulum (SR) 1 Ca 2ϩ modulation, leading to aberrant cardiac contraction and relaxation (4 -8). Although several Ca 2ϩ -related signaling molecules, such as calcineurin, Ca 2ϩ -calmodulin kinase, and Ca 2ϩ

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Section: Discussionmentioning

confidence: 93%

Rescue of Contractile Parameters and Myocyte Hypertrophy in Calsequestrin Overexpressing Myocardium by Phospholamban Ablation

Sato

Kiriazis²,

Yatani³

et al. 2001

Journal of Biological Chemistry

103

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“…Compensatory expression of skeletal ␣-actin is also seen in adult BALB͞c mice, which have a mutant cardiac ␣-actin locus and decreased cardiac ␣-actin levels (2). Skeletal and vascular smooth muscle ␣-actin mRNAs accumulate in the adult rat heart, the former transiently, following hypertrophy induced by pressure overload (7,39,40). While the pattern of compensation in the newborn ϩ͞Ϫ and Ϫ͞Ϫ hearts is in some ways reminescent of the expression seen in the hypertrophied hearts, there are no morphological changes in the newborn ϩ͞Ϫ hearts that would suggest hypertrophy (not shown).…”

Section: Discussionmentioning

confidence: 99%

“…Similarly, there is a preponderance of cardiac ␣-actin mRNA in the heart of the adult chicken (4), mouse (2,5), and rat (6)(7)(8). However, the adult human heart has more skeletal than cardiac ␣-actin mRNA (9).…”

mentioning

confidence: 99%

Rescue of cardiac α-actin-deficient mice by enteric smooth muscle γ-actin

Kumar

Crawford

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

176

166

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The muscle actins in higher vertebrates display highly conserved amino acid sequences, yet they show distinct expression patterns. Thus, cardiac ␣-actin, skeletal ␣-actin, vascular smooth muscle ␣-actin, and enteric smooth muscle ␥-actin comprise the major actins in their respective tissues. To assess the functional and developmental significance of cardiac ␣-actin, the murine (129͞SvJ) cardiac ␣-actin gene was disrupted by homologous recombination. The majority (Ϸ56%) of the mice lacking cardiac ␣-actin do not survive to term, and the remainder generally die within 2 weeks of birth. Increased expression of vascular smooth muscle and skeletal ␣-actins is observed in the hearts of newborn homozygous mutants and also heterozygotes but apparently is insufficient to maintain myofibrillar integrity in the homozygous mutants. Mice lacking cardiac ␣-actin can be rescued to adulthood by the ectopic expression of enteric smooth muscle ␥-actin using the cardiac ␣-myosin heavy chain promoter. However, the hearts of such rescued cardiac ␣-actin-deficient mice are extremely hypodynamic, considerably enlarged, and hypertrophied. Furthermore, the transgenically expressed enteric smooth muscle ␥-actin reduces cardiac contractility in wild-type and heterozygous mice. These results demonstrate that alterations in actin composition in the fetal and adult heart are associated with severe structural and functional perturbations.

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“…hypertension), often leads to irreversible cardiomyopathy and heart failure. The pathological hypertrophic response is characterized by the transcriptional activation of fetal genes encoding contractile proteins such as ␤-MHC and skeletal ␣-actin (8,9). The synthesis of atrial natriuretic factor (ANF) is also induced, presumably mimicking the cardiac response to pressure overload (10).…”

mentioning

confidence: 99%

Mammalian Target of Rapamycin and Protein Kinase A Signaling Mediate the Cardiac Transcriptional Response to Glutamine

Xia¹,

Wen²,

Young³

et al. 2003

Journal of Biological Chemistry

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The addition of glutamine as a major nutrient to cultured neonatal rat cardiomyocytes produced an increase in myocyte size and the organization of actin into myofibrillar arrays. The cellular response was associated with increased abundance of the mRNAs encoding the contractile proteins, ␣-myosin heavy chain and cardiac ␣-actin, and the metabolic enzymes, muscle carnitine palmitoyl transferase I and muscle adenylosuccinate synthetase (ADSS1). Adss1 gene expression was induced ϳ5-fold in glutamine-treated rat neonatal cardiac myocytes. The induction was mediated through the protein kinase A and mammalian target of rapamycin signaling pathways and required a cyclic AMP response element associated with the promoter region of the Adss1 gene. These results highlight glutamine as a major nutrient regulator of cardiac gene expression and identify protein kinase A and mammalian target of rapamycin signaling pathways as mediators of the cardiomyocyte transcriptional response.

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Alpha-skeletal muscle actin mRNA's accumulate in hypertrophied adult rat hearts.

Cited by 275 publications

References 25 publications

Rescue of Contractile Parameters and Myocyte Hypertrophy in Calsequestrin Overexpressing Myocardium by Phospholamban Ablation

Rescue of Contractile Parameters and Myocyte Hypertrophy in Calsequestrin Overexpressing Myocardium by Phospholamban Ablation

Rescue of cardiac α-actin-deficient mice by enteric smooth muscle γ-actin

Mammalian Target of Rapamycin and Protein Kinase A Signaling Mediate the Cardiac Transcriptional Response to Glutamine

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