Similar Datasets
Project description:As we age, structural changes contribute to progressive decline in organ function, which in the heart acts through poorly characterized mechanisms. Utilizing the rapidly aging fruit fly model with its significant homology to the human cardiac proteome, we found that cardiomyocytes exhibit progressive loss of Lamin C (mammalian Lamin A/C homologue) with age. Unlike other tissues and laminopathies, we observe decreasing nuclear size, while nuclear stiffness increases. Premature genetic reduction of Lamin C phenocopies aging’s effects on the nucleus, and subsequently decreases heart contractility and sarcomere organization. Surprisingly, Lamin C reduction downregulates myogenic transcription factors and cytoskeletal regulators, possibly via reduced chromatin accessibility. Subsequently, we find an adult-specific role for cardiac transcription factors and show that maintenance of Lamin C sustains their expression and prevents age-dependent cardiac decline. Our findings are conserved in aged non-human primates and mice, demonstrating age-dependent nuclear remodeling is a major mechanism contributing to cardiac dysfunction.
2022-11-01 | GSE185967 | GEO
Project description:As we age, structural changes contribute to progressive decline in organ function, which in the heart acts through poorly characterized mechanisms. Utilizing the rapidly aging fruit fly model with its significant homology to the human cardiac proteome, we found that cardiomyocytes exhibit progressive loss of Lamin C (mammalian Lamin A/C homologue) with age. Unlike other tissues and laminopathies, we observe decreasing nuclear size, while nuclear stiffness increases. Premature genetic reduction of Lamin C phenocopies aging’s effects on the nucleus, and subsequently decreases heart contractility and sarcomere organization. Surprisingly, Lamin C reduction downregulates myogenic transcription factors and cytoskeletal regulators, possibly via reduced chromatin accessibility. Subsequently, we find an adult-specific role for cardiac transcription factors and show that maintenance of Lamin C sustains their expression and prevents age-dependent cardiac decline. Our findings are conserved in aged non-human primates and mice, demonstrating age-dependent nuclear remodeling is a major mechanism contributing to cardiac dysfunction.
2022-11-01 | GSE185923 | GEO
Project description:Background. Ageing is one of the main risk factors of cardiovascular disease. Pericytes are capillary-associated mural cells involved in the maintenance and stability of the vascular network. In the heart, the consequences of ageing on cardiac pericytes are unknown. Methods. In this study, we have combined single nucleus RNA sequencing and histological analysis to determine the effects of ageing on cardiac pericytes. Furthermore, we have conducted in vivo and in vitro analysis of RGS5 loss of function and finally have perfomed pericytes-fibroblasts co-culture studies to understand the effect of RGS5 loss of function in pericytes on the neighbouring fibroblasts. Results. We showed that ageing reduces the pericyte area and coverage. Single nucleus RNA sequencing analysis further revealed that the expression of the Regulator of G protein signalling 5 (Rgs5) is reduced in old cardiac pericytes. In vivo and in vitro studies showed that the deletion of RGS5 induces morphological changes and a pro-fibrotic gene expression signature characterized by the expression of different extracellular matrix components and growth factors like TGFB2 and PDGFB in pericytes. Indeed, the culture of fibroblasts with the supernatant of RGS5 deficient pericytes induced their activation characterized by the increased expression of α smooth muscle actin in a TFGβ2 dependent mechanism. Conclusions. Our results identify RGS5 as a crucial regulator of pericyte function during cardiac ageing. The deletion of RGS5 causes cardiac dysfunction and induces myocardial fibrosis, one of the hallmarks of cardiac ageing.
2024-03-06 | E-MTAB-13841 | biostudies-arrayexpress
Project description:Background. Ageing is one of the main risk factors of cardiovascular disease. Pericytes are capillary-associated mural cells involved in the maintenance and stability of the vascular network. In the heart, the consequences of ageing on cardiac pericytes are unknown. Methods. In this study, we have combined single nucleus RNA sequencing and histological analysis to determine the effects of ageing on cardiac pericytes. Furthermore, we have conducted in vivo and in vitro analysis of RGS5 loss of function and finally have perfomed pericytes-fibroblasts co-culture studies to understand the effect of RGS5 loss of function in pericytes on the neighbouring fibroblasts. Results. We showed that ageing reduces the pericyte area and coverage. Single nucleus RNA sequencing analysis further revealed that the expression of the Regulator of G protein signalling 5 (Rgs5) is reduced in old cardiac pericytes. In vivo and in vitro studies showed that the deletion of RGS5 induces morphological changes and a pro-fibrotic gene expression signature characterized by the expression of different extracellular matrix components and growth factors like TGFB2 and PDGFB in pericytes. Indeed, the culture of fibroblasts with the supernatant of RGS5 deficient pericytes induced their activation characterized by the increased expression of α smooth muscle actin in a TFGβ2 dependent mechanism. Conclusions. Our results identify RGS5 as a crucial regulator of pericyte function during cardiac ageing. The deletion of RGS5 causes cardiac dysfunction and induces myocardial fibrosis, one of the hallmarks of cardiac ageing.
2024-03-13 | E-MTAB-13833 | biostudies-arrayexpress
Project description:Hypertrophic cardiomyopathy (HCM) is one of the most frequent inherited heart condition and a well-established risk factor for cardiovascular mortality worldwide. Although hypertrophy is traditionally regarded as an adaptive response to increased workload caused by physiological or pathological stress, prolonged hypertrophy can lead to heart failure characterized by impaired systolic function, increased apoptosis, fibrosis, ventricular dilation, and impaired metabolic substrate flexibility. While the key regulators for cardiac hypertrophy are well studied, the role of Prdm16 in this process remains poorly understood. In the present study, we demonstrate that Prdm16 is dispensable for cardiac development. However, it is required in the adult heart to preserve mitochondrial function and inhibit hypertrophy with advanced age. Cardiac-specific deletion of Prdm16 results in cardiac hypertrophy, excessive ventricular fibrosis, mitochondrial dysfunction, and impaired metabolic flexibility, leading to heart failure. We demonstrate that Prdm16 and euchromatic histone-lysine N- methyltransferase factors (Ehmts) act together to reduce the expression of fetal genes reactivated in pathological hypertrophy by inhibiting the functions of pro- hypertrophic transcription factor Myc. Although young Prdm16 knockout mice show normal cardiac function, they are predisposed to develop heart failure in response to metabolic stress. Collectively, our results demonstrate that Prdm16 protects the heart against age-dependent cardiac hypertrophy, fibrosis, mitochondrial dysfunction, adverse metabolic remodeling, and heart failure.
2020-09-21 | GSE153988 | GEO
Project description:Heart Failure (HF) is the leading cause of death worldwide. Myocardial fibrosis, one of the clinical manifestations implicated in almost every form of heart disease, contributes significantly to HF development. However, there is no approved drug specifically designed to target cardiac fibrosis. Nintedanib (NTB) is an FDA approved tyrosine kinase inhibitor for idiopathic pulmonary fibrosis (IPF) and chronic fibrosing interstitial lung diseases (ILD). The favorable clinical outcome of NTB in IPF patients is well established. Furthermore, NTB is well tolerated in IPF patients irrespective of cardiovascular comorbidities. However, there is a lack of direct evidence to support the therapeutic efficacy and safety of NTB in cardiac diseases. In this study we examined the effects of NTB treatment on cardiac fibrosis and dysfunction using a murine model of HF. Specifically, 10 weeks old C57BL/6J male mice were subjected to Transverse Aortic Constriction (TAC) surgery. NTB was administered once daily by oral gavage (50 mg/kg) till 16 weeks post-TAC. Cardiac function was monitored by serial echocardiography. Histological analysis and morphometric studies were performed at 16 weeks post-TAC. In the control group, systolic dysfunction started developing from 4 weeks post-surgery and progressed till 16 weeks. However, NTB treatment prevented TAC-induced cardiac functional decline. In another experiment, NTB treatment was stopped at 8 weeks, and animals were followed till 16 weeks post-TAC. Surprisingly, NTB's beneficial effect on cardiac function was maintained even after treatment interruption. NTB treatment remarkably reduced cardiac fibrosis as confirmed by Masson's trichrome staining and decreased expression of collagen genes (COL1A1, COL3A1). Compared to the TAC group, NTB treated mice showed a lower HW/TL ratio and cardiomyocyte cross-sectional area. NTB treatment reduced myocardial and systemic inflammation by inhibiting pro-inflammatory subsets and promoting regulatory T cells (Tregs). Our in vitro studies demonstrated that NTB prevents myofibroblast transformation, TGFβ1-induced SMAD3 phosphorylation, and the production of fibrogenic proteins (Fibronectin-1, α-SMA). However, NTB promoted immunosuppressive phenotype in Tregs, and altered vital signaling pathways in isolated cardiac fibroblast and cardiomyocytes, suggesting that its biological effect and underlying cardiac protection mechanisms are not limited to fibroblast and fibrosis alone. Our findings provide a proof of concept for repurposing NTB to combat adverse myocardial fibrosis and encourage the need for further validation in large animal models and subsequent clinical development for HF patients.
| S-EPMC8217286 | biostudies-literature
Project description:Obscurin comprises a family of giant modular proteins that play key structural and regulatory roles in striated muscles. Immunoglobulin domains 58/59 (Ig58/59) of obscurin mediate binding to essential modulators of muscle structure and function, including canonical titin, a smaller splice variant of titin, termed novex-3, and phospholamban (PLN). Importantly, missense mutations localized within the obscurin-Ig58/59 region that affect binding to titins and/or PLN have been linked to the development of myopathy in humans. To elucidate the pathophysiological role of this region, we generated a constitutive deletion mouse model, Obscn-ΔIg58/59, that expresses obscurin lacking Ig58/59, and determined the consequences of this manipulation on cardiac morphology and function under conditions of acute stress and through the physiological process of aging. Our studies show that young Obscn-ΔIg58/59 mice are susceptible to acute β-adrenergic stress. Moreover, sedentary Obscn-ΔIg58/59 mice develop left ventricular hypertrophy that progresses to dilation, contractile impairment, atrial enlargement, and arrhythmia as a function of aging with males being more affected than females. Experiments in ventricular cardiomyocytes revealed altered Ca2+ cycling associated with changes in the expression and/or phosphorylation levels of major Ca2+ cycling proteins, including PLN, SERCA2, and RyR2. Taken together, our work demonstrates that obscurin-Ig58/59 is an essential regulatory module in the heart and its deletion leads to age- and sex-dependent cardiac remodeling, ventricular dilation, and arrhythmia due to deregulated Ca2+ cycling.
| S-EPMC9302192 | biostudies-literature
Project description:Hyperglycemia is an independent risk factor for diabetic cardiomyopathy in humans; however, the underlying mechanisms have not been thoroughly elucidated. Zebrafish (Danio rerio) was used in this study as a novel vertebrate model to explore the signaling pathways of human adult cardiomyopathy. Hyperglycemia was induced by alternately immersing adult zebrafish in a glucose solution or water. The hyperglycemic fish gradually exhibited some hallmarks of cardiomyopathy such as myocardial hypertrophy and apoptosis, myofibril loss, fetal gene reactivation, and severe arrhythmia. Echocardiography of the glucose-treated fish demonstrated diastolic dysfunction at an early stage and systolic dysfunction at a later stage, consistent with what is observed in diabetic patients. Enlarged hearts with decreased myocardial density, accompanied by decompensated cardiac function, indicated that apoptosis was critical in the pathological process. Significant upregulation of the expression of Nkx2.5 and its downstream targets calreticulin (Calr) and p53 was noted in the glucose-treated fish. High-glucose stimulation in vitro evoked marked apoptosis of primary cardiomyocytes, which was rescued by the p53 inhibitor pifithrin-?. In vitro experiments were performed using compound treatment and genetically via cell infection. Genetically, knockout of Nkx2.5 induced decreased expression of Nkx2.5, Calr and p53 Upregulation of Calr resulted in increased p53 expression, whereas the level of Nkx2.5 remained unchanged. An adult zebrafish model of hyperglycemia-induced cardiomyopathy was successfully established. Hyperglycemia-induced myocardial apoptosis was mediated, at least in part, by activation of the Nkx2.5-Calr-p53 pathway in vivo, resulting in cardiac dysfunction and hyperglycemia-induced cardiomyopathy.
| S-EPMC5665450 | biostudies-other
Project description:Patients with diabetes, a methionine-rich meat diet, or certain genetic polymorphisms show elevated levels of homocysteine (Hcy), which is strongly associated with the development of cardiovascular disease including diabetic cardiomyopathy. However, reducing Hcy levels with folate shows no beneficial cardiac effects. We have previously shown that a hydrogen sulfide (H2S), a by-product of Hcy through transsulfuration by cystathionine beta synthase (CBS), donor mitigates Hcy-induced hypertrophy in cardiomyocytes. However, the in vivo cardiac effects of H2S in the context of hyperhomocysteinemia (HHcy) have not been studied. We tested the hypothesis that HHcy causes cardiac remodeling and dysfunction in vivo, which is ameliorated by H2S. Twelve-week-old male CBS+/- (a model of HHcy) and sibling CBS+/+ (WT) mice were treated with SG1002 (a slow release H2S donor) diet for 4 months. The left ventricle of CBS+/- mice showed increased expression of early remodeling signals c-Jun and c-Fos, increased interstitial collagen deposition, and increased cellular hypertrophy. Notably, SG1002 treatment slightly reduced c-Jun and c-Fos expression, decreased interstitial fibrosis, and reduced cellular hypertrophy. Pressure volume loop analyses in CBS+/- mice revealed increased end systolic pressure with no change in stroke volume (SV) suggesting increased afterload, which was abolished by SG1002 treatment. Additionally, SG1002 treatment increased end-diastolic volume and SV in CBS+/- mice, suggesting increased ventricular filling. These results demonstrate SG1002 treatment alleviates cardiac remodeling and afterload in HHcy mice. H2S may be cardioprotective in conditions where H2S is reduced and Hcy is elevated.
| S-EPMC6544124 | biostudies-literature
Project description:ObjectivePreliminary data suggest that nonalcoholic fatty liver disease is associated with early heart failure (HF). However, whether nonalcoholic steatohepatitis (NASH) is directly associated with echocardiographic changes in cardiac structure or function remains unknown.MethodsA retrospective cohort was identified of individuals (N = 65) without known heart disease, undergoing elective bariatric surgery with perioperative liver biopsy, and available recent transthoracic echocardiography (TTE). TTE measures were evaluated by NASH status using correlation coefficients, ANOVA, and linear regression, accounting for cardiometabolic factors.ResultsMedian age was 47 years; 22% (n = 14) had NASH. NASH patients had increased median left atrial (LA) volume (28.6 mL/m2 vs. 24.8 mL/m2 ; P < 0.0001) and left ventricular (LV) mass (82.6 g/m2 vs. 78.6 g/m2 ; P < 0.0001), indexed for height. NASH was inversely correlated with indices of diastolic function, including septal E' (r = -0.90 [95% CI: -1.21 to -0.42]; P = 0.020) and E:A (r = -0.31 [95% CI: -0.51 to -0.09]; P = 0.037). In adjusted analyses, NASH remained associated with increased LV mass index (ß1 = 7.16 [SE: 4.95]; P = 0.001) and LA volume index (ß1 = 0.19 [SE: 0.08]; P = 0.001) and reduced lateral and septal E' (ß1 = -0.91, P = 0.015; ß1 = -0.89, P = 0.047, respectively).ConclusionsIn this bariatric cohort, NASH was associated with changes in myocardial structure and in load-dependent indices of LV diastolic function, suggestive of subclinical HF.
| S-EPMC5648006 | biostudies-literature