Project description:Objective: Cardiac aging is a major risk factor for the development of cardiovascular diseases. Although evidence suggests an association between N6-methyladenosine (m6A) modification and numerous cardiovascular diseases, its role in cardiac aging remains unclear. This study was conducted to elucidate the role of m6A modification in cardiac aging and the molecular mechanisms involved. Methods: Global methylation levels and the expression of major m6A regulators were compared between young and aged hearts. Transcriptome-wide m6A landscape analysis was conducted using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) to identify aberrant m6A peaks. Furthermore, gene set enrichment analysis (GSEA) was performed to identify gene sets associated with cardiac aging. Functional validation of key molecules was carried out through in vitro experiments. Results: The overall m6A level remained constant; however, the expression of the methyltransferase METTL14 and the demethyltransferase FTO were significantly upregulated in aged hearts. Knockdown of METTL14 alleviated H2O2-induced senescence phenotypes, as reflected by a reduction in the number of SA-β-gal positive cells and a decrease in p21 expression. Compared with young hearts, the dysregulated m6A peaks were significantly enriched in genes associated with dilated cardiomyopathy, hypertrophic cardiomyopathy, and the PI3K-Akt signaling pathway. GSEA showed that these genes were enriched in the aging of heart and aorta cardiomyocytes. Additionally, 255 genes with siginificantly changed of both m6A peaks and RNA expression were identified by combining MeRIP-seq and RNA-seq data. Among these genes, EFEMP1 was significantly upregulated in aged hearts, accompanied by enhanced m6A modification. Treatment with the methyltransferase inhibitor cycloleucine significantly suppressed the expression level of EFEMP1. In AC16 cells, silencing EFEMP1 suppressed H2O2-induced cell senescence. Furthermore, we found a positive correlation between METTL14 and EFEMP1 in multiple datasets related to cardiac aging. Conclusion: Our findings indicate that m6A modification plays an essential role in the process of cardiac aging. EFEMP1 may serve as a potential new therapeutic target for age-related cardiac diseases.
Project description:Objective: To study the effect of astragalus polysaccharide combined with metformin on mRNA expression profile of type 2 diabetic mice, and to explore the molecular mechanism of astragalus polysaccharide combined with metformin in the treatment of type 2 aging diabetes. Methods: Natural aging mice were induced by high-sugar and high-fat diet combined with streptozotocin to prepare aging diabetes model. The experimental mice were divided into aging control group, aging diabetes model group, metformin treatment group, astragalus polysaccharide and metformin. The treatment group was treated with gavage for 60 consecutive days. Immunohistochemical detection of insulin levels in pancreatic tissue of each group of mice, serum insulin levels were measured by mouse insulin kit to observe the treatment of aging diabetes and astragalus polysaccharide combined with metformin; using Agilent mouse whole gene expression profile chip The mRNA expression changes of liver tissues in each group were analyzed, and the differential genes were screened by bioinformatics tools and the differential genes and signal pathways were enriched and analyzed. Results: Compared with the aging group, the insulin and insulin antibody levels in the model group were significantly decreased (P<0.05). Compared with the model group, the insulin and insulin antibody levels in the two treatment groups increased (P<0.05), and jaundice The level of polysaccharide in combination with metformin was significantly higher than that in metformin group (P<0.05). The differential gene analysis of the chip showed that there were 5617 differential genes in the aging diabetes model group, 3131 were up-regulated, and 2486 were down-regulated; the Astragalus polysaccharide combined with metformin treatment group had 4767 differential genes, compared with the aging diabetes model group. 2143 up-regulated, 2624 down-regulated, genes with significant differences were mainly involved in protease activity and drug metabolism, and significantly enriched into 33 signaling pathways (P<0.01). Conclusion: The gene regulatory network plays an important role in the intervention of Astragalus polysaccharides and metformin in the treatment of aging type 2 diabetes.
Project description:Objective: To study the effect of astragalus polysaccharide combined with metformin on mRNA expression profile of type 2 diabetic mice, and to explore the molecular mechanism of astragalus polysaccharide combined with metformin in the treatment of type 2 aging diabetes. Methods: Natural aging mice were induced by high-sugar and high-fat diet combined with streptozotocin to prepare aging diabetes model. The experimental mice were divided into aging control group, aging diabetes model group, metformin treatment group, astragalus polysaccharide and metformin. The treatment group was treated with gavage for 60 consecutive days. Immunohistochemical detection of insulin levels in pancreatic tissue of each group of mice, serum insulin levels were measured by mouse insulin kit to observe the treatment of aging diabetes and astragalus polysaccharide combined with metformin; using Agilent mouse whole gene expression profile chip The mRNA expression changes of liver tissues in each group were analyzed, and the differential genes were screened by bioinformatics tools and the differential genes and signal pathways were enriched and analyzed. Results: Compared with the aging group, the insulin and insulin antibody levels in the model group were significantly decreased (P<0.05). Compared with the model group, the insulin and insulin antibody levels in the two treatment groups increased (P<0.05), and jaundice The level of polysaccharide in combination with metformin was significantly higher than that in metformin group (P<0.05). The differential gene analysis of the chip showed that there were 5617 differential genes in the aging diabetes model group, 3131 were up-regulated, and 2486 were down-regulated; the Astragalus polysaccharide combined with metformin treatment group had 4767 differential genes, compared with the aging diabetes model group. 2143 up-regulated, 2624 down-regulated, genes with significant differences were mainly involved in protease activity and drug metabolism, and significantly enriched into 33 signaling pathways (P<0.01). Conclusion: The gene regulatory network plays an important role in the intervention of Astragalus polysaccharides and metformin in the treatment of aging type 2 diabetes.
Project description:To understand how reduced insulin/IGF-1 signaling extends Drosophila lifespan through its downstream transcription factor dFOXO. We conducted ChIP analysis with a dFOXO antibody followed by Illumina high-throughput sequencing from chico heterozygous mutants, which are long-lived and normal sized, and from adult flies with ablated insulin producing cells (IPCs), which are also long-lived. dFOXO bound at promoters of 273 genes common among these genotypes, thus potentially enriching for shared factors in control of aging. Two replicates were sequenced from chico heterozygous mutants and IPC ablated flies.
Project description:Using a model of cardiac AC8 overexpression that lead to accelerated cardiac aging, fibrosis and immune system overactivation, this study used scRNA-seq to investigate the signaling pathways dysregulated in cardiac cells to have a better understanding of the biological processes invoved in cardiac aging.
Project description:Insulin-like growth factor (IGF1R) signalling has been implicated to play an important role in regulation of cardiac growth, hypertrophy and contractile function, and has been linked to the development of age related congestive heart failure. Here we address the question to what extent cardiomyocyte specific IGF1 signalling is essential for maintenance of the structural and functional integrity of the adult murine heart. To investigate the effects of IGF1 signalling in the adult heart without confounding effects due to IGF1 over-expression or adaptation during embryonic and early post-natal development, we inactivated the IGF1R by a 4-hydroxy tamoxifen inducible Cre recombinase in adult cardiac myocytes. Efficient inactivation of the IGF1R (iCMIGF1RKO) as assessed by Western analysis and real-time PCR went along with reduced IGF1-dependent AKT and GSK3β-phosphorylation. Functional analysis by conductance manometry and magnetic resonance imaging (MRI) revealed no functional alterations in young adult iCMIGF1RKO mice (age 3 month). However, when induced in aged mice (11 month) diastolic cardiac function was depressed. To address the question if insulin signalling might compensate for the defective IGF1R signalling we inactivated β-cells by streptozotocin. However, the diabetes associated functional depression was similar in controls and iCMIGF1RKO mice. Similarly, analysis of the cardiac gene expression profile on 44K microarrays did not reveal activation of overt adaptive processes. Endogenous IGF1 receptor signalling is required for conservation of cardiac function of the aging heart, but not for the integrity of cardiac structure and function of young hearts. Four samples of each group: the control group, positive for Cre recombinase, but negative for the floxed IGF-1R and the experimental group with double transgenic mice (merCremer/+ IGFloxP/IGFloxP).
Project description:The myokine irisin is involved in the regulation of a variety of physiological conditions, metabolism, and survival. We and others have demonstrated that recombinant irisin contributes critically to modulation of insulin resistance and cardiac function. However, the molecular mechanisms by which irisin exerts its physiological effects on cardiac function and insulin sensitivity remain unclear. We utilized the CRISPR/Cas9 genome editing system to delete irisin. Irisin deficiency did not result in abnormalities in development, growth, or cardiac function; however, gene expression profiling showed that several key signaling pathways related to growth, insulin signaling, and integrin signaling were coordinately downregulated. However, loss of irisin resulted in more severe insulin resistance and metabolic derangement when mice were exposed to a high fat diet, which was associated with profound cardiac dysfunction and hypertrophic remodeling. In addition, the loss of irisin also exacerbated myocardial ischemia-reperfusion injury, as indicated by a reduction of post-ischemic ventricular function and an increase in infarct size. Taken together, our results indicate that loss of irisin exacerbates insulin resistance and cardiac depression in response to high fat diet and promotes myocardial ischemia-reperfusion injury. This evidence suggests a role for irisin in modulating insulin resistance, cardiac function and ischemic injury.