Project description:Cardiac pathological hypertrophy is associated with a significantly increased risk of coronary heart disease and has been observed in diabetic patients treated with rosiglitazone, whereas most published studies do not suggest a similar increase in risk of cardiovascular events in pioglitazone-treated diabetic subjects. This study sought to understand the pathophysiological mechanisms underlying the disparate cardiovascular effects of rosiglitazone and pioglitazone and yield knowledge as to the causative nature of rosiglitazone-associated cardiac hypertrophy.
Project description:Cardiac pathological hypertrophy is associated with a significantly increased risk of coronary heart disease and has been observed in diabetic patients treated with rosiglitazone, whereas most published studies do not suggest a similar increase in risk of cardiovascular events in pioglitazone-treated diabetic subjects. This study sought to understand the pathophysiological mechanisms underlying the disparate cardiovascular effects of rosiglitazone and pioglitazone and yield knowledge as to the causative nature of rosiglitazone-associated cardiac hypertrophy. Total RNA obtained from mouse Apex from LDLr-/- mice treated with High Fat diet (HF) diet as control (n=6) or HF+Pio (n=5) or HF+Rosi (n=5).
Project description:The study of the mechanisms leading to cardiac hypertrophy is essential to better understand cardiac development and regeneration. Pathological conditions such as ischemia or pressure overload can induce a release of extracellular nucleotides within the heart. We recently investigated the potential role of nucleotide P2Y receptors in cardiac development. We showed that adult P2Y4-null mice displayed microcardia resulting from defective cardiac angiogenesis. Here we show that loss of another P2Y subtype called P2Y6, a UDP receptor, was associated with a macrocardia phenotype and amplified pathological cardiac hypertrophy. Cardiomyocyte proliferation and size were increased in vivo in hearts of P2Y6-null neonates, resulting in enhanced post-natal heart growth. We then observed that loss of P2Y6 receptor enhanced pathological cardiac hypertrophy induced after isoproterenol injection. We identified an inhibitory effect of UDP on in vitro isoproterenol-induced cardiomyocyte hyperplasia and hypertrophy. The present study identifies mouse P2Y6 receptor as a regulator of cardiac development and cardiomyocyte function. P2Y6 receptor could constitute a therapeutic target to regulate cardiac hypertrophy.
Project description:Cardiac hypertrophy consists in the enlargement of cardiomyocytes and alteration of the extracellular matrix organization in response to physiological or pathological stress. In pathological hypertrophy ocuurs myocardial damage, loss of cardiomyocytes, fibrosis, inflammation, sarcomere disorganization and metabolic impairment, leading to cardiac dysfunction.The rodent model treated with isoproterenol induces cardiac hypertrophy due the constant activation of β-adrenergic receptors. We conducted a quantitative label-free proteomic analysis of cardiomyocytes isolated from hearts of mice treated or not with isoproterenol to better understand the molecular bases of cellular response due to isoproterenol-induced injury.
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:Rosiglitazone, a peroxisome proliferator-activated receptor g (PPARg) agonist of the thiazolidinedione class, is a major insulin-sensitizing drug widely used to treat type-2 diabetes. Rosiglitazone causes myocardial hypertrophy in rodents and increases the risk of cardiac events in man. To better characterize its cardiac effects, male Wistar rats were orally administered 0, 10 or 80 mg/kg/day rosiglitazone.
Project description:Although current studies have demonstrated that lncRNAs play an important part in the pathophysiological process of cardiac disease, whether lncRNAs are associated with the protective role of puerarin in myocardial hypertrophy remains unknown. In the present study, RNA sequencing (RNA-seq) was performed to systematically understand the function of lncRNAs in the pharmacological action of puerarin in myocardial hypertrophy.
Project description:Rosiglitazone, a peroxisome proliferator-activated receptor g (PPARg) agonist of the thiazolidinedione class, is a major insulin-sensitizing drug widely used to treat type-2 diabetes. Rosiglitazone causes myocardial hypertrophy in rodents and increases the risk of cardiac events in man. To better characterize its cardiac effects, male Wistar rats were orally administered 0, 10 or 80 mg/kg/day rosiglitazone. Male Wistar rats were orally administered 0, 10 or 80 mg/kg/day rosiglitazone once per day for 14 days. Samples were obtained 6, 24, 168 or 336 hours after the final treatment.
Project description:PIWI-interacting RNAs (piRNAs) are abundantly expressed during cardiac hypertrophy development, but their influence on pathological hypertrophy and the underlying mechanisms remains to be elucidated. Here, we identified a cardiac-hypertrophy-associated piRNA (CHAPIR), and we found that it regulates pathological hypertrophy. To investigate the molecular mechanisms by which CHAPIR regulates cardiomyocyte hypertrophy, we transfected the biotinylated CHAPIR into cardiomyocytes and performed streptavidin bead pull down assay. The CHAPIR pull-down materials and its control were resolved using SDS-PAGE gel and stained with coomassie blue. Then the entire gel lanes of the CHAPIR pull-down materials and its control were excised and send for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis.