Project description:Cardiac hypertrophy is a pathological feature of heart failure, and dysregulation of protein turnover and autophagy has been implicated in its progression. Speckle-type POZ protein (SPOP), a substrate adaptor for the Cullin3-RING E3 ubiquitin ligase complex, plays an emerging role in protein homeostasis and transcriptional regulation. This study investigates the function of SPOP in cardiac hypertrophy and heart failure. RNA sequencing was performed to examine transcriptional changes in mouse hearts with cardiac-specific overexpression of SPOP, revealing differential expression of genes involved in autophagy, mitochondrial metabolism, and cardiac remodeling. These data provide new insights into the transcriptional landscape regulated by SPOP in the hypertrophic heart.
Project description:Pressure overload-induced cardiac hypertrophy and heart failure involve profound remodeling of the myocardial proteome. To elucidate the role of the E3 adaptor protein SPOP in this process, we performed TMT-based quantitative proteomic analysis on left ventricular tissues collected four weeks after transverse aortic constriction (TAC) from Myh6-Cre control mice (n=5) and cardiac-specific SPOP knockout (cKO) mice (n=5).
Project description:Purpose: The physiological cardiac hypertrophy is an adaptive condition that does not associate with myocyte cell death while pathological hypertrophy is a maladaptive condition associated with myocyte cell death. Alpha-2 macroglobulin (α-2M) an acute phase protein induces cardiac hypertrophy via the ERK1,2 and PI3K/Akt signaling. This study is aimed at exploring the miRNome of α-2M induced hypertrophied cardiomyocytes and to understand the role of miRNAs in determination of pathological and physiological hypertrophy. Methods: Hypertrophy was induced in H9c2 cardiomyoblasts using alpha-2 macroglobulin. The induction of hypertrophy is confirmed by microscopy and gene expression studies. Subsequently, the total RNA was isolated and small RNA sequencing was executed in Illumina HiSeq 2000. Results: Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during hypertrophy. Among the differentially expressed candidates, miR-99 family (miR-99a, miR-99b and miR-100) showed significant downregulation upon α-2M treatment while isoproterenol treatment (pathological hypertrophy) upregulated their expression. The binding site for Egr1 transcription factor was identified in the promoter region of miR-99 family, and interestingly all miRNAs with Egr1 binding site proven by ChIP-Seq were downregulated during physiological hypertrophy Conclusions: The results proved Egr-1 mediated regulation of miR-99 family determines the uniqueness of pathological and physiological hypertrophy. Upregulated miR-99 expression during pathological hypertrophy suggests that it can be a valuable diagnostic marker and potential therapeutic target for cardiac hypertrophy and heart failure. Small RNA profiles of control and hypertrophied cardiomyocyte H9c2 cells were generated by deep sequencing using Illumina HiSeq 2000
Project description:Cardiac hypertrophy can lead to heart failure, and is induced either by physiological stimuli eg postnatal development, chronic exercise training or pathological stimuli eg pressure or volume overload. Majority of new therapies for heart failure has mixed outcomes. A combined mouse model and oligo-array approach are used to examine whether phosphoinositide 3-kinase (p110-alpha isoform) activity is critical for maintenance of cardiac function and long-term survival in a setting of heart failure. The significance and expected outcome are to recognise genes involved in models of heart failure ie pathological- vs physiology-hypertrophy, and examine the molecular mechanisms responsible for such activity. Growth of the heart can be induced by physiological stimuli e.g., postnatal development, chronic exercise training, or pathological stimuli e.g., pressure or volume overload. Physiological hypertrophy (“good”) is characterised by a normal organisation of cardiac structure, and normal or enhanced cardiac function. In comparison, pathological hypertrophy (”bad”) is associated with fibrosis, cardiac dysfunction, and increased morbidity and mortality. The mechanistic process which allows the heart to enlarge in response to physiological stimuli while maintaining normal or enhanced function is of great clinical relevance because one potential therapeutic strategy is to inhibit the pathological growth process while augmenting the physiological growth process. One of the major process that regulate heart size is by phosphoinositide 3-kinase (PI3K). Thus the end goal of this project is to determine whether the p110 alpha isoform of PI3K could be a potential tool for augmenting physiological growth and improving cardiac function of the failing diseased heart, and to examine the underlying mechanisms responsible. Keywords: Disease progression analysis
Project description:Purpose: The physiological cardiac hypertrophy is an adaptive condition that does not associate with myocyte cell death while pathological hypertrophy is a maladaptive condition associated with myocyte cell death. Alpha-2 macroglobulin (α-2M) an acute phase protein induces cardiac hypertrophy via the ERK1,2 and PI3K/Akt signaling. This study is aimed at exploring the miRNome of α-2M induced hypertrophied cardiomyocytes and to understand the role of miRNAs in determination of pathological and physiological hypertrophy. Methods: Hypertrophy was induced in H9c2 cardiomyoblasts using alpha-2 macroglobulin. The induction of hypertrophy is confirmed by microscopy and gene expression studies. Subsequently, the total RNA was isolated and small RNA sequencing was executed in Illumina HiSeq 2000. Results: Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during hypertrophy. Among the differentially expressed candidates, miR-99 family (miR-99a, miR-99b and miR-100) showed significant downregulation upon α-2M treatment while isoproterenol treatment (pathological hypertrophy) upregulated their expression. The binding site for Egr1 transcription factor was identified in the promoter region of miR-99 family, and interestingly all miRNAs with Egr1 binding site proven by ChIP-Seq were downregulated during physiological hypertrophy Conclusions: The results proved Egr-1 mediated regulation of miR-99 family determines the uniqueness of pathological and physiological hypertrophy. Upregulated miR-99 expression during pathological hypertrophy suggests that it can be a valuable diagnostic marker and potential therapeutic target for cardiac hypertrophy and heart failure.
Project description:Here, we performed pathological cardiac hypertrophy transcriptome analyses by using heart tissue from Sham or TAC surgery to identify the charecteric in pathological cardiac hypertrophy. In addition, through combined analysis with the aging-associated transcriptome to identify the similarity and difference between heart ageing and pathological cardiac hypertrophy.
Project description:The identification of key factors involved in pathological cardiac hypertrophy is crucial to exploring novel treatments for heart failure. In this study, we elucidated the role of Ubiquitin-specific protease 29 (USP29), a deubiquitinase, in pressure overload-induced cardiac hypertrophy. Genetic knockout of USP29 in mice significantly exacerbated TAC-induced heart hypertrophy, dysfunction, and fibrosis; whereas overexpression of USP29 in cardiomyocytes attenuated the hypertrophic response. Similarly, USP29 markedly alleviated PE-induced hypertrophy of primary neonatal rat cardiomyocytes. Mechanistically, the cardio-protective effects mediated by USP29 were attributed to its suppression of transforming growth factor β-activated kinase 1 (TAK1)-JNK/P38 signaling pathway activation. Collectively, our study suggests that targeting either USP29 or its interaction with TAK1 could represent an innovative therapeutic strategy for treating heart failure and cardiac hypertrophy.
Project description:Pathological cardiac hypertrophy can lead to heart failure and is one of the leading causes of death globally. Understanding the molecular mechanism of pathological cardiac hypertrophy will contribute to the treatment of heart failure. Deubiquitinating enzymes (DUBs) are essential to cardiac pathophysiology by precisely controlling protein function, localization, and degradation.This study set out to investigate the role of a DUB, USP25, in pathological cardiac hypertrophy, reveal its molecular mechanism, and hopefully provide a new therapeutic target for heart failure.We revealed increased protein level of USP25 expression in the cardiomyocytes in response to Ang II stimulation. USP25 deficiency aggravated cardiac hypertrophy and cardiac dysfunction under Ang II and TAC treatment. Mechanistically, LC-MS/MS analysis combined with Co-IP was used to identify SERCA2a, an anti-hypertrophy protein, as an interacting protein of USP25. Also, our data showed that USP25 bound to SERCA2a directly via its USP domain and cysteine at position 178 of USP25 exerts deubiquitination to maintain the stability of the SERCA2a protein by removing the K48 ubiquitin chain and preventing proteasomal pathway degradation, thereby maintaining calcium content in cardiomyocytes. Moreover, restoration of USP25 expression via with AAV9 vectors in USP25-/- mice attenuated Ang II-induced cardiac hypertrophy and cardiac dysfunction, whereas SERCA2a myocardial overexpression could offset the effect of USP25.
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.