Novel Protective Role of Myeloid Differentiation 1 in Pathological Cardiac Remodelling.
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ABSTRACT:
SUBMITTER: Xiong X
PROVIDER: S-EPMC5292962 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:AimsMyeloid differentiation protein 1 (MD1) was shown to ameliorate pressure overload-induced cardiac hypertrophy and fibrosis by negatively regulating the MEK-ERK1/2 and NF-κB pathways. However, whether MD1 modulates cardiac function and whether the Akt pathway mediates the benefits of MD1 in pressure overload-induced cardiac remodelling remain unclear.Methods and resultsMale cardiac-specific transgenic MD1 (MD1-TG) mice, MD1-knockout (KO) mice and wild-type (WT) littermates aged 8-10 weeks were subjected to sham operation and aortic banding (AB) for 4 weeks. Then, left ventricular (LV) hypertrophy, fibrosis and function of the mice were assessed. When compared with WT-AB mice, MD1-TGs showed decreased cross-sectional area (CSA) of cardiomyocytes (P < 0.001), mRNA expression of β-myosin heavy chain (β-MHC) (P < 0.02), ratios of heart weight/body weight and heart weight/tibia length (P < 0.04) and collagen volume fraction (P < 0.001). The LV end-diastolic diameter was reduced, and LV ejection fraction and fractional shortening were improved in MD1-TG-AB mice than in WT-AB mice (P < 0.05). In cultured H9C2 cells, adenovirus vector-mediated MD1 overexpression decreased angiotensin II-induced mRNA expression of brain natriuretic peptide (BNP) and β-MHC and cell CSA (P < 0.002), whereas knockdown of MD1 by shRNA exhibited opposite effects (P < 0.04). Mechanistically, MD1 suppressed pathological cardiac remodelling at least partly by blocking Akt pathway. Akt inactivation by MK2206 largely offset the pro-hypertrophic effects of MD1 deficiency in angiotensin II-stimulated cardiomyocytes.ConclusionsThe Akt pathway mediates the protective effects of MD1 in pressure overload-induced cardiac remodelling in mice. Targeting MD1 may provide therapeutic strategy for the treatment of pathological cardiac remodelling and heart failure.
| S-EPMC8318477 | biostudies-literature
Project description:Interferon regulatory factor 8 (IRF8) is known to affect the innate immune response, for example, by regulating the differentiation and function of immune cells. However, whether IRF8 can influence cardiac hypertrophy is unknown. Here we show that IRF8 levels are decreased in human dilated/hypertrophic cardiomyopathic hearts and in murine hypertrophic hearts. Mice overexpressing Irf8 specifically in the heart are resistant to aortic banding (AB)-induced cardiac hypertrophy, whereas mice lacking IRF8 either globally or specifically in cardiomyocytes develop an aggravated phenotype induced by pressure overload. Mechanistically, we show that IRF8 directly interacts with NFATc1 to prevent NFATc1 translocation and thus inhibits the hypertrophic response. Inhibition of NFATc1 ameliorates the cardiac abnormalities in IRF8(-/-) mice after AB. In contrast, constitutive activation of NFATc1 nullifies the protective effects of IRF8 on cardiac hypertrophy in IRF8-overexpressing mice. Our results indicate that IRF8 is a potential therapeutic target in pathological cardiac hypertrophy.
| S-EPMC3929801 | biostudies-other
Project description:BackgroundTranslocase of inner membrane 50 (TIM50) is a member of the translocase of inner membrane (TIM) complex in the mitochondria. Previous research has demonstrated the role of TIM50 in the regulation of oxidative stress and cardiac morphology. However, the role of TIM50 in pathological cardiac hypertrophy remains unknown.Methods and resultsIn the present study we found that the expression of TIM50 was downregulated in hypertrophic hearts. Using genetic loss-of-function animal models, we demonstrated that TIM50 deficiency increased heart and cardiomyocyte size with more severe cardiac fibrosis compared with wild-type littermates. Moreover, we generated cardiomyocyte-specific TIM50 transgenic mice in which the hypertrophic and fibrotic phenotypes were all alleviated. Next, we tested reactive oxygen species generation and the activities of the antioxidant enzymes superoxide dismutase and catalase, and also respiratory chain complexes I, II, and IV, finding that all the activities were regulated by TIM50. Meanwhile, expression of the ASK1-JNK/P38 axis was increased in TIM50-deficient mice, and TIM50 overexpression decreased the activity of the ASK1-JNK/P38 axis. Finally, we treated mice with the antioxidant N-acetyl cysteine to reduce oxidative stress. After N-acetyl cysteine treatment, the deteriorative hypertrophic and fibrotic phenotypes caused by TIM50 deficiency were all remarkably reversed.ConclusionsThese data indicated that TIM50 could attenuate pathological cardiac hypertrophy primarily by reducing oxidative stress. TIM50 could be a promising target for the prevention and therapy of cardiac hypertrophy and heart failure.
| S-EPMC5532988 | biostudies-literature
Project description:Pathological cardiac remodeling correlates with chronic neurohumoral stimulation and abnormal Ca2+ signaling in cardiomyocytes. Store-operated calcium entry (SOCE) has been described in adult and neonatal murine cardiomyocytes, and Orai1 proteins act as crucial ion-conducting constituents of this calcium entry pathway that can be engaged not only by passive Ca2+ store depletion but also by neurohumoral stimuli such as angiotensin-II. In this study, we, therefore, analyzed the consequences of Orai1 deletion for cardiomyocyte hypertrophy in neonatal and adult cardiomyocytes as well as for other features of pathological cardiac remodeling including cardiac contractile function in vivo. Cellular hypertrophy induced by angiotensin-II in embryonic cardiomyocytes from Orai1-deficient mice was blunted in comparison to cells from litter-matched control mice. Due to lethality of mice with ubiquitous Orai1 deficiency and to selectively analyze the role of Orai1 in adult cardiomyocytes, we generated a cardiomyocyte-specific and temporally inducible Orai1 knockout mouse line (Orai1CM-KO). Analysis of cardiac contractility by pressure-volume loops under basal conditions and of cardiac histology did not reveal differences between Orai1CM-KO mice and controls. Moreover, deletion of Orai1 in cardiomyocytes in adult mice did not protect them from angiotensin-II-induced cardiac remodeling, but cardiomyocyte cross-sectional area and cardiac fibrosis were enhanced. These alterations in the absence of Orai1 go along with blunted angiotensin-II-induced upregulation of the expression of Myoz2 and a lack of rise in angiotensin-II-induced STIM1 and Orai3 expression. In contrast to embryonic cardiomyocytes, where Orai1 contributes to the development of cellular hypertrophy, the results obtained from deletion of Orai1 in the adult myocardium reveal a protective function of Orai1 against the development of angiotensin-II-induced cardiac remodeling, possibly involving signaling via Orai3/STIM1-calcineurin-NFAT related pathways.
| S-EPMC7290784 | biostudies-literature
Project description:AimsCardiac hypertrophy and heart failure are associated with QT prolongation and lethal ventricular arrhythmias resulting from decreased K(+) current densities and impaired repolarization. Recent studies in mouse models of physiological cardiac hypertrophy revealed that increased phosphoinositide-3-kinase-? (PI3K?) signalling results in the up-regulation of K(+) channels and the normalization of ventricular repolarization. The experiments here were undertaken to test the hypothesis that increased PI3K? signalling will counteract the adverse electrophysiological remodelling associated with pathological hypertrophy and heart failure.Methods and resultsIn contrast to wild-type mice, left ventricular (LV) hypertrophy, induced by transverse aortic constriction (TAC), did not result in prolongation of ventricular action potentials or QT intervals in mice with cardiac-specific expression of constitutively active PI3K? (caPI3K?). Indeed, repolarizing K(+) currents and K(+) channel subunit transcripts were increased in caPI3K? + TAC LV myocytes in proportion to the TAC-induced cellular hypertrophy. Congestive heart failure in a transgenic model of dilated cardiomyopathy model is accompanied by prolonged QT intervals and ventricular action potentials, reduced K(+) currents and K(+) channel transcripts. Increased PI3K? signalling, but not renin-angiotensin system blockade, in this model also results in increased K(+) currents and improved ventricular repolarization.ConclusionIn the setting of pathological hypertrophy or heart failure, enhanced PI3K? signalling results in the up-regulation of K(+) channel subunits, normalization of K(+) current densities and preserved ventricular function. Augmentation of PI3K? signalling, therefore, may be a useful and unique strategy to protect against the increased risk of ventricular arrhythmias and sudden death associated with cardiomyopathy.
| S-EPMC3258651 | biostudies-literature
Project description:BackgroundHeart failure (HF), despite continuing progress, remains a leading cause of mortality and morbidity. P2X4 receptors (P2X4R) have emerged as potentially important molecules in regulating cardiac function and as potential targets for HF therapy. Transgenic P2X4R overexpression can protect against HF, but this does not explain the role of native cardiac P2X4R. Our goal is to define the physiological role of endogenous cardiac myocyte P2X4R under basal conditions and during HF induced by myocardial infarction or pressure overload.Methods and resultsMice established with conditional cardiac-specific P2X4R knockout were subjected to left anterior descending coronary artery ligation-induced postinfarct or transverse aorta constriction-induced pressure overload HF. Knockout cardiac myocytes did not show P2X4R by immunoblotting or by any response to the P2X4R-specific allosteric enhancer ivermectin. Knockout hearts showed normal basal cardiac function but depressed contractile performance in postinfarct and pressure overload models of HF by in vivo echocardiography and ex vivo isolated working heart parameters. P2X4R coimmunoprecipitated and colocalized with nitric oxide synthase 3 (eNOS) in wild-type cardiac myocytes. Mice with cardiac-specific P2X4R overexpression had increased S-nitrosylation, cyclic GMP, NO formation, and were protected from postinfarct and pressure overload HF. Inhibitor of eNOS, L-N(5)-(1-iminoethyl)ornithine hydrochloride, blocked the salutary effect of cardiac P2X4R overexpression in postinfarct and pressure overload HF as did eNOS knockout.ConclusionsThis study establishes a new protective role for endogenous cardiac myocyte P2X4R in HF and is the first to demonstrate a physical interaction between the myocyte receptor and eNOS, a mediator of HF protection.
| S-EPMC4289151 | biostudies-literature
Project description:BackgroundHeart failure is a leading cause of death worldwide. Cyclic nucleotide phosphodiesterases (PDEs), through degradation of cyclic nucleotides, play critical roles in cardiovascular biology and disease. Our preliminary screening studies have revealed PDE10A upregulation in the diseased heart. However, the roles of PDE10A in cardiovascular biology and disease are largely uncharacterized. The current study is aimed to investigate the regulation and function of PDE10A in cardiac cells and in the progression of cardiac remodeling and dysfunction.MethodsWe used isolated adult mouse cardiac myocytes and fibroblasts, as well as preclinical mouse models of hypertrophy and heart failure. The PDE10A selective inhibitor TP-10, and global PDE10A knock out mice were used.ResultsWe found that PDE10A expression remains relatively low in normal and exercised heart tissues. However, PDE10A is significantly upregulated in mouse and human failing hearts. In vitro, PDE10A deficiency or inhibiting PDE10A with selective inhibitor TP-10, attenuated cardiac myocyte pathological hypertrophy induced by Angiotensin II, phenylephrine, and isoproterenol, but did not affect cardiac myocyte physiological hypertrophy induced by IGF-1 (insulin-like growth factor 1). TP-10 also reduced TGF-? (transforming growth factor-?)-stimulated cardiac fibroblast activation, proliferation, migration and extracellular matrix synthesis. TP-10 treatment elevated both cAMP and cGMP levels in cardiac myocytes and cardiac fibroblasts, consistent with PDE10A as a cAMP/cGMP dual-specific PDE. In vivo, global PDE10A deficiency significantly attenuated myocardial hypertrophy, cardiac fibrosis, and dysfunction induced by chronic pressure overload via transverse aorta constriction or chronic neurohormonal stimulation via Angiotensin II infusion. Importantly, we demonstrated that the pharmacological effect of TP-10 is specifically through PDE10A inhibition. In addition, TP-10 is able to reverse pre-established cardiac hypertrophy and dysfunction. RNA-Sequencing and bioinformatics analysis further identified a PDE10A-regualted transcriptome involved in cardiac hypertrophy, fibrosis, and cardiomyopathy.ConclusionsTaken together, our study elucidates a novel role for PDE10A in the regulation of pathological cardiac remodeling and development of heart failure. Given that PDE10A has been proven to be a safe drug target, PDE10A inhibition may represent a novel therapeutic strategy for preventing and treating cardiac diseases associated with cardiac remodeling.
| S-EPMC7147986 | biostudies-literature
Project description:Heart failure is a growing health issue as a negative consequence of improved survival upon myocardial infarction, unhealthy lifestyle, and the ageing of our population. The large and complex pathology underlying heart failure makes diagnosis and especially treatment very difficult. There is an urgent demand for discriminative biomarkers to aid disease management of heart failure. Studying cellular pathways and pathophysiological mechanisms contributing to disease initiation and progression is crucial for understanding the disease process and will aid to identification of novel biomarkers and potential therapeutic targets. Growth differentiation factor 15 (GDF15) is a proven valuable biomarker for different pathologies, including cancer, type 2 diabetes, and cardiovascular diseases. Although the prognostic value of GDF15 in heart failure is robust, the biological function of GDF15 in adverse cardiac remodelling is not fully understood. GDF15 is a distant member of the transforming growth factor-? family and involved in various biological processes including inflammation, cell cycle, and apoptosis. However, more research is suggesting a role in fibrosis, hypertrophy, and endothelial dysfunction. As GDF15 is a pleiotropic protein, elucidating the exact role of GDF15 in complex disease processes has proven to be a challenge. In this review, we provide an overview of the role GDF15 plays in various intracellular and extracellular processes underlying heart failure, and we touch upon crucial points that need consideration before GDF15 can be integrated as a biomarker in standard care or when considering GDF15 for therapeutic intervention.
| S-EPMC7373942 | biostudies-literature
Project description:BACKGROUND AND PURPOSE: Mitogen-activated protein kinases (MAPK) are centrally involved in several mechanisms important for heart failure such as apoptosis, activation of inflammatory responses and cell proliferation. We therefore evaluated the effect of the selective p38 MAPK inhibitor SB 239063 on progression of left ventricular remodelling after myocardial infarction (MI) in rats. EXPERIMENTAL APPROACH: Rats were treated for 9 weeks with placebo or SB 239063 by gavage (15 mg kg(-1)) twice daily starting 7 days after ligation of the left anterior descending artery. Serial transthoracic echocardiography was performed at days 7, 36 and 70. KEY RESULTS: Over the 9 weeks, mortality was not different between the groups. On echocardiography, animals after myocardial infarction exhibited significant left ventricular dilatation as expected (week 10, end-systolic diameter, placebo sham 5.21+/- 0.34 vs. placebo MI 8.44+/- 0.57 mm). However, there was no difference between placebo and SB 239063-treated rats (week 10, end-systolic diameter, SB MI 7.76+/- 0.74 mm, not significantly different from placebo MI). Haemodynamics changed accordingly. Moreover, SB 239063 had no effect on left ventricular hypertrophy. Treatment with SB 239063 significantly reduced cytokine expression of tumour necrosis factor and interleukin-1beta after myocardial infarction. However, collagen content was not influenced by the treatment. CONCLUSION: Despite a reduction of inflammation, treatment with the p38 inhibitor SB 239063 does not affect cardiac remodelling and cardiac function when treatment is started 7 days after myocardial infarction.
| S-EPMC2042905 | biostudies-other
Project description:Heart failure is a life-threatening condition that carries a considerable emotional and socio-economic burden. As a result of the global increase in the ageing population, sedentary life-style, increased prevalence of risk factors, and improved survival from cardiovascular events, the incidence of heart failure will continue to rise. Despite the advances in current cardiovascular therapies, many patients are not suitable for or may not benefit from conventional treatments. Thus, more effective therapies are required. Transforming growth factor (TGF) β family of cytokines is involved in heart development and dys-regulated TGFβ signalling is commonly associated with fibrosis, aberrant angiogenesis and accelerated progression into heart failure. Therefore, a potential therapeutic pathway is to modulate TGFβ signalling; however, broad blockage of TGFβ signalling may cause unwanted side effects due to its pivotal role in tissue homeostasis. We found that leucine-rich α-2 glycoprotein 1 (LRG1) promotes blood vessel formation via regulating the context-dependent endothelial TGFβ signalling. This review will focus on the interaction between LRG1 and TGFβ signalling, their involvement in the pathogenesis of heart failure, and the potential for LRG1 to function as a novel therapeutic target.
| S-EPMC4322186 | biostudies-literature