Bulk RNA sequecing reveals the heterogeneity of fibroblasts in the diabetic heart
Ontology highlight
ABSTRACT: Diabetes mellitus is one of the most chronic diseases, of which diabetic cardiomyopathy is the major cause of morbidity and involves in multiple processes such as inflammation, oxidative stress, fibrosis, extracellular collagen deposition, apoptosis, mitochondria dysfunction.
Project description:Diabetes mellitus is one of the most chronic diseases, of which diabetic cardiomyopathy is the major cause of morbidity and involves in multiple processes such as inflammation, oxidative stress, fibrosis, extracellular collagen deposition, apoptosis, mitochondria dysfunction. However, the exact mechanisms of fibroblasts concerning type Ⅰ diabetes remain unclear. To further understand the functional roles of fibroblasts of STZ-induced diabetic mice, we lead the single cell RNA sequence. Cells were comprised of endothelial, fibroblast, cardiomyocyte, smooth muscle cells, macrophage and other type cells. Single cell sequence illustrates novel fibroblast sub-clusters and highlight the role of Lox. Real-time quantitative PCR, western blotting, immunofluorescence was used to verify the sequence data. We validate the dysfunctions of diabetic cardiomyopathy by echocardiogram. Our study supports novel insights into the pathogenesis of diabetic cardiomyopathy.
Project description:Diabetes is associated with cardiovascular complications. microRNAs translocate into subcellular organelles to modify genes involved in diabetic cardiomyopathy. However, functional properties of subcellular Ago2, a core microRNA, remain elusive. We elucidated the function and mechanism of subcellular localized Ago2 on mouse models for diabetes mellitus and diabetic cardiomyopathy. Ago2 decreased in cardiomyocyte mitochondria in both models. Overexpression of mitochondrial Ago2 attenuated diabetes-induced cardiac dysfunction. Ago2 recruited TUFM, a mitochondria translation elongation factor, to activate translation of electron transport chain (ETC) subunits and decrease reactive oxygen species. Malonylation, a post-translational modification of Ago2, reduced the importing of Ago2 into mitochondria in diabetic cardiomyopathy. Ago2 malonylation was regulated by a cytoplasmic-localized short isoform of SIRT3 through a previously unknown demalonylase function. Our results reveal that the SIRT3–Ago2–CYTB axis links glucotoxicity to cardiac ETC imbalance, providing new mechanistic insights and the basis to develop mitochondria targeting therapies for diabetic cardiomyopathy.
Project description:Diabetes is associated with cardiovascular complications. microRNAs translocate into subcellular organelles to modify genes involved in diabetic cardiomyopathy. However, functional properties of subcellular Ago2, a core microRNA, remain elusive. We elucidated the function and mechanism of subcellular localized Ago2 on mouse models for diabetes mellitus and diabetic cardiomyopathy. Ago2 decreased in cardiomyocyte mitochondria in both models. Overexpression of mitochondrial Ago2 attenuated diabetes-induced cardiac dysfunction. Ago2 recruited TUFM, a mitochondria translation elongation factor, to activate translation of electron transport chain (ETC) subunits and decrease reactive oxygen species. Malonylation, a post-translational modification of Ago2, reduced the importing of Ago2 into mitochondria in diabetic cardiomyopathy. Ago2 malonylation was regulated by a cytoplasmic-localized short isoform of SIRT3 through a previously unknown demalonylase function. Our results reveal that the SIRT3–Ago2–CYTB axis links glucotoxicity to cardiac ETC imbalance, providing new mechanistic insights and the basis to develop mitochondria targeting therapies for diabetic cardiomyopathy.
Project description:Diabetes is associated with cardiovascular complications. microRNAs translocate into subcellular organelles to modify genes involved in diabetic cardiomyopathy. However, functional properties of subcellular Ago2, a core microRNA, remain elusive. We elucidated the function and mechanism of subcellular localized Ago2 on mouse models for diabetes mellitus and diabetic cardiomyopathy. Ago2 decreased in cardiomyocyte mitochondria in both models. Overexpression of mitochondrial Ago2 attenuated diabetes-induced cardiac dysfunction. Ago2 recruited TUFM, a mitochondria translation elongation factor, to activate translation of electron transport chain (ETC) subunits and decrease reactive oxygen species. Malonylation, a post-translational modification of Ago2, reduced the importing of Ago2 into mitochondria in diabetic cardiomyopathy. Ago2 malonylation was regulated by a cytoplasmic-localized short isoform of SIRT3 through a previously unknown demalonylase function. Our results reveal that the SIRT3–Ago2–CYTB axis links glucotoxicity to cardiac ETC imbalance, providing new mechanistic insights and the basis to develop mitochondria targeting therapies for diabetic cardiomyopathy.
Project description:Diabetes is associated with cardiovascular complications. microRNAs translocate into subcellular organelles to modify genes involved in diabetic cardiomyopathy. However, functional properties of subcellular Ago2, a core microRNA, remain elusive. We elucidated the function and mechanism of subcellular localized Ago2 on mouse models for diabetes mellitus and diabetic cardiomyopathy. Ago2 decreased in cardiomyocyte mitochondria in both models. Overexpression of mitochondrial Ago2 attenuated diabetes-induced cardiac dysfunction. Ago2 recruited TUFM, a mitochondria translation elongation factor, to activate translation of electron transport chain (ETC) subunits and decrease reactive oxygen species. Malonylation, a post-translational modification of Ago2, reduced the importing of Ago2 into mitochondria in diabetic cardiomyopathy. Ago2 malonylation was regulated by a cytoplasmic-localized short isoform of SIRT3 through a previously unknown demalonylase function. Our results reveal that the SIRT3–Ago2–CYTB axis links glucotoxicity to cardiac ETC imbalance, providing new mechanistic insights and the basis to develop mitochondria targeting therapies for diabetic cardiomyopathy.
Project description:Increased morbidity and mortality associated with post-ischemic heart failure (HF) in diabetic patients underscore the need for a better understanding of the underlying molecular events. Indeed, effective HF therapy in diabetic patients requires a complex strategy encompassing the development of improved diagnostic and prognostic markers and innovative pharmacological approaches. Whole mRNAs expression was measured in the heart of patients with heart failure (HF) with or without concomitant Type 2 diabetes mellitus (T2DM) and compared it to control non-failing hearts. We identified distinct genes modulated in HF patients compared to controls, as well as to T2DM HF patients compared to not diabetic HF patients. Our study included left ventricle (LV) cardiac biopsies taken from the vital, non-infarcted zone (remote zone) derived from patients affected by dilated hypokinetic post-ischemic cardiomyopathy, undergoing surgical ventricular restoration procedure. Inclusion criteria for diabetic were: GLICEMIA: >=126 mg/dl, previous T2DM diagnosis or anti-diabetic therapy, while for non diabetic: GLICEMIA: <100 mg/dl and HbA1c: n.v. 4.8-6.0%. Moreover, HF patients were matched for End Systolic Volume (ESV), Ejection fraction (LVEF), Age, Sex, Ethnic distribution, Smoke habits, Hypertension, Glomerular filtration rate (GFR), Body Mass Index (BMI). Genes expression was assessed by Affymetrix GeneChips Human Gene 1.0 ST array, using total RNA extracted from 7 T2DM HF patients, 12 non-T2DM HF patients and 5 controls.
Project description:Increased morbidity and mortality associated with post-ischemic heart failure (HF) in diabetic patients underscore the need for a better understanding of the underlying molecular events. Indeed, effective HF therapy in diabetic patients requires a complex strategy encompassing the development of improved diagnostic and prognostic markers and innovative pharmacological approaches. Whole mRNAs expression was measured in the heart of patients with heart failure (HF) with or without concomitant Type 2 diabetes mellitus (T2DM) and compared it to control non-failing hearts. We identified distinct genes modulated in HF patients compared to controls, as well as to T2DM HF patients compared to not diabetic HF patients.
Project description:Diabetic cardiomyopathy (DCM) is an important complication of chronic diabetes mellitus (DM). However, its pathogenesis and pathologic process have not been fully elucidated. This study was aimed to investigate the role of ferroptosis in the pathogenesis of DCM and clarify the effect of HMOX1 on DCM by targeting ferroptosis. DCM mouse model was constructed by high fat diet (HFD) feeding and streptozotocin (STZ). injection.
Project description:It is well known that rennin-angiotensin-aldosterone system (RAAS) plays a critical role in the development of diabetic cardiomyopathy. The present study was aimed to clarify the role of a novel member of RAAS, angiotensin IV (Ang IV) and its downstream mediator forkhead box protein O1 (FoxO1), in the pathogenesis of diabetic cardiomyopathy. In vivo, diabetic mice were treated with low-, medium- and high-dose Ang IV, AT4R antagonist divalinal, FoxO1 inhibitor AS1842856 (AS), or their combinations. In vitro, cardiomyocytes and cardiofibroblasts were treated with different concentrations of glucose, low-, medium- and high-dose Ang IV, divalinal, FoxO1-overexpression plasmid (FoxO1-OE), AS or their combinations. The results showed that Ang IV treatment dose-dependently attenuated left ventricular dysfunction, fibrosis, and myocyte apoptosis in diabetic mice. Besides, enhanced autophagy and FoxO1 protein expression by diabetes were dose-dependently suppressed by Ang IV treatment. However, these cardioprotective effects of Ang IV were completely abolished by divalinal administration. Bioinformatics analysis revealed that the differentially expressed genes were enriched in autophagy, apoptosis, and FoxO signaling pathways among control, diabetes, and diabetes+high-dose Ang IV groups. Similar to Ang IV, AS treatment ameliorated diabetic cardiomyopathy in mice. In vitro, high glucose stimulation increased collagen expression, apoptosis, overactive autophagy flux and FoxO1 nuclear translocation in cardiomyocytes, and upregulated collagen and FoxO1 expression in cardiofibroblasts, which were substantially attenuated by Ang IV treatment. However, these protective effects of Ang IV were completely blocked by the use of divalinal or FoxO1-OE, and these detrimental effects were reversed by the additional administration of AS. In summary, Ang IV treatment dose-dependently attenuated left ventricular dysfunction and remodeling in a mouse model of diabetic cardiomyopathy, and the mechanisms involved stimulation of AT4R and suppression of FoxO1-mediated fibrosis, apoptosis, and overactive autophagy.