Project description:Male patients (n=6, mean age 62 years) with NYHA III-IV and an left ventricular ejection fraction of <35% despite pharmacological therapy received 35 hours of enhanced external counterpulsation (EECP) over a period of 7 weeks. Before and after treatment, lateral vastus muscle biopsies were obtained and skeletal muscle gene expression was evaluated using the Affymetrix HuGene 1.0 platform. Skeletal muscle gene expression before and after treatment with enhanced external counterpulsation for 7 weeks in 6 male patients with severe heart failure
Project description:Heart failure is a multisystem syndrome caused by structural and functional defects in multiple tissues. The study aims to identify differentially regulated genes in skeletal muscle of heart failure patients. Here, we obtained biopsies from the pectoralis major muscle and performed RNA sequencing to profile the gene expression patterns from six heart failure patients and three healthy controls.
Project description:Cachexia is associated with poor prognosis in patients with chronic heart failure. The underlying mechanisms of cachexia triggered heart failure progression, however, are not well understood. Here, we investigated whether the dysregulation of myokine expression from wasting skeletal muscle and impaired inter-organ crosstalk during advanced heart failure might contribute to progression of the disease. RNA sequencing analysis from wasting skeletal muscles of mice with cardiac cachexia during long-term pressure overload revealed a strongly reduced expression of Ostn. Ostn encodes for the skeletal muscle derived myokine Musclin, which had been previously implicated in the enhancement of natriuretic peptide (NP) signaling. Using newly developed skeletal muscle specific, inducible Ostn knock-out mice, we demonstrated that reduced skeletal muscle Musclin levels exaggerated cardiac dysfunction and myocardial fibrosis compared to littermate control mice after TAC. Restoration of Musclin deficiency during cardiac cachexia via AAV6-mediated skeletal muscle specific Musclin overexpression, in turn, attenuated left ventricular dysfunction and myocardial fibrosis. Mechanistically, we found that Musclin enhanced CNP/NPR2/cGMP signaling in cardiomyocytes, which led to improved contractility by inhibition of the cAMP degrading phosphodiesterase (PDE)3 and augmented cAMP/protein kinase A signaling. In addition, Musclin directly acted on cardiac fibroblasts to inhibit their activation. Together, our study indicates the therapeutic potential of targeting interorgan cross-talk during heart failure, for example by counteracting the impaired secretion of the Musclin from wasting skeletal muscle.
Project description:Cardiac cachexia is a common complication of heart failure in severe cases and is associated with a poor prognosis. Several skeletal muscle abnormalities have been described in patients and animals with cardiac cachexia; these include atrophy, fibrosis, altered myosin heavy chain composition, and decreased oxidative capacity. It is also well established that gene expression patterns are substantially altered in cardiac cachexia, but the reasons for such differences are not clear.
Project description:Ischemia, fibrosis, and remodeling lead to heart failure after severe myocardial infarction (MI). Myoblast sheet transplantation is a promising therapy to enhance cardiac function and induce therapeutic angiogenesis via a paracrine mechanism in this detrimental disease. We hypothesized that in a rat model of MI-induced chronic heart failure this therapy could further be improved by overexpression of the antiapoptotic, antifibrotic, and proangiogenic hepatocyte growth factor (HGF) in the myoblast sheets. We studied the ability of wild type (L6-WT) and human HGF-expressing (L6-HGF) L6 myoblast sheet-derived paracrine factors to stimulate cardiomyocyte, endothelial cell, or smooth muscle cell migration in culture. Further, we studied the autocrine effect of hHGF-expression on myoblast gene expression using microarray analysis. We induced MI in Wistar rats by left anterior descending coronary artery (LAD) ligation and allowed heart failure to develop for four weeks. Thereafter, we administered L6-WT (n=15) or L6-HGF (n=16) myoblast sheet therapy. Control rats (n=13) underwent LAD ligation and rethoracotomy without therapy and five rats underwent sham-operation in both surgeries. We evaluated cardiac function with echocardiography at 2 and 4 weeks after therapy administration. We analyzed cardiac angiogenesis and left ventricular architecture from histological sections 4 weeks after therapy. Paracrine mediators from L6-HGF myoblast sheets effectively induced migration of cardiac endothelial and smooth muscle cells but not cardiomyocytes. Microarray data revealed that hHGF-expression modulated myoblast gene expression. In vivo, L6-HGF sheet therapy effectively stimulated angiogenesis in the infarcted and non-infarcted areas. Both L6-WT and L6-HGF therapies enhanced cardiac function and inhibited remodeling in a similar fashion. In conclusion, L6-HGF therapy effectively induced angiogenesis in the chronically failing heart. Cardiac function, however, was not further enhanced by hHGF-expression. Analysis of the L6 rat skeletal myoblast cell line and myoblast cell sheets with constitutive human HGF expression.
Project description:TK2 deficiency causes severe mtDNA depeltion in several tissues, including skeletal muscle and heart. TK2 knockout mice grow slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal size. We used microarrays in order to compare the transcriptomes in skeletal muscle and heart tissue of 11 days-old TK2 knockout pups with the sames tissues of wild-type pups at the same age. We collected skeletal muscle from the hind limb and hearts of three 11 days-old TK2 knockout and three wild-type pups and extracted total RNA. These RNA samples were used for hybridization in Affymetrix arrays.
Project description:Male patients (n=6, mean age 62 years) with NYHA III-IV and an left ventricular ejection fraction of <35% despite pharmacological therapy received 35 hours of enhanced external counterpulsation (EECP) over a period of 7 weeks. Before and after treatment, lateral vastus muscle biopsies were obtained and skeletal muscle gene expression was evaluated using the Affymetrix HuGene 1.0 platform.
Project description:Heart failure and associated cachexia is an unresolved and important problem. We report a new model of severe heart failure that consistently results in cachexia. Mice lacking the integrated stress response (ISR) induced eIF2α phosphatase, PPP1R15A, exhibit a dilated cardiomyopathy and severe weight loss following irradiation, whilst wildtype mice are unaffected. This is associated with increased expression of Gdf15 in the heart and increased levels of GDF15 in the circulation. We provide evidence that blockade of GDF15 activity prevents cachexia and slows the progression of heart failure. Our data suggests that cardiac stress mediates a GDF15 dependent pathway that drives weight loss and worsens cardiac function. We show relevance of GDF15 to lean mass and protein intake with patients with heart failure. Blockade of GDF15 could constitute a novel therapeutic option to limit cardiac cachexia and improve clinical outcomes in patients with severe systolic heart failure.
Project description:TK2 deficiency causes severe mtDNA depeltion in several tissues, including skeletal muscle and heart. TK2 knockout mice grow slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal size. We used microarrays in order to compare the transcriptomes in skeletal muscle and heart tissue of 11 days-old TK2 knockout pups with the sames tissues of wild-type pups at the same age.
Project description:Females with heart failure and reduced ejection fraction (HFrEF) have greater physical limitations and a lower quality of life compared to males, however, the role of non-cardiac mechanisms remains poorly resolved. We hypothesized that differences in skeletal muscle pathology between males and females with HFrEF may explain clinical heterogeneity. In this study, we performed an unbiased RNA sequencing of 5 male controls, 5 female controls, 6 male HFrEF patients, and 5 female HFrEF patients.