Project description:Optimal treatment for nonalcoholic steatohepatitis (NASH) has not yet been established, particularly for individuals without diabetes. We examined the effects of metformin, commonly used to treat patients with type 2 diabetes, on liver pathology in a non-diabetic NASH mouse model. Eight-week-old C57BL/6 mice were fed a methionine- and choline-deficient (MCD) + high fat (HF) diet with or without 0.1% metformin for 8 weeks.
Project description:To investigate the effects of imeglimin and metformin on islet cells in db/db mice, we isolated pancreatic islets from db/db mice treated with/without imeglimin and metformin or db/+ mice.
Project description:The biguanide metformin improves health and survival in male mice; however, it is unclear whether metformin will confer health and lifespan benefits to mice when started late in life. Two year-old mice fed on standard chow were treated with 1% metformin every-other week (EOW) or two consecutive weeks per month (2WM). EOW mice displayed improvements in healthspan reminiscent of mice on caloric restriction. The age-associated histopathological changes in liver and kidney were significantly reduced in EOW compared to 2WM or control mice. Some of the affected gene transcripts and metabolites were found to be risk predictors of metabolic disorder. Neither EOW nor 2WM mice exhibited extension in mean or maximum lifespan compared with control animals. Thus, metformin supplementation had a strong impact on reversing some of the deleterious effects of aging and resulted in an improvement of health in old male mice in the absence of an extension of lifespan.
Project description:Here we investigate the nature of cellular heterogeneity in the gene expression of aging and characterize the changes that metformin causes in mouse adipose and muscle at the single-cell resolution. The single cell transcriptomes of ~13,000 cells were captured using single-cell RNA-sequencing, resulting in gene expression data for 13 cell types from the visceral adipose tissue stromal-vascular fraction and ~5,000 cells from 12 cell types from the gastrocnemius muscle. The study design featured three groups of male C57BL/6J mice that corresponded to three-month-old controls (young), 18-month-old controls (old), and 18-month-olds treated with 1000 ppm (0.1% w/w) metformin for 6 weeks (treated). Our analyses demonstrate that metformin’s age-associated changes results in the modulation of an old to young expression profile via a cell type-specific manner. This reversion is demonstrated by significant changes observed in cell-type proportions and the degree of cell-cell heterogeneity. Additionally, metformin is known to restore the dysregulation due to age in autophagy and immune response in adipose, hypoxia in muscle, and inflammatory responses in both tissues. In our data, we detect evidence of these processes at play where endothelial cells, macrophages, and stem/progenitor cells respond most effectively to metformin’s gerotherapeutic response compared to other cell types. We further characterize metformin’s role in reverting age-associated cell-type-specific shifts in the transcriptional space by investigating changes in gene expression distributions and gene regulatory network dynamics.
Project description:Metformin, a commonly used drug prescribed to treat type-2 diabetes, has been found to extend health span and delay cancer incidence and progression. Here, we report that starting chronic treatment with low dose of metformin (0.1% w/w in diet) at one year of age extends health and lifespan in male mice, while a higher dose (1% w/w) was toxic. Treatment with low dose metformin mimicked some of the benefits of calorie restriction, such as improved physical performance, increased insulin sensitivity, and reduced LDL and cholesterol levels. At a molecular level, metformin increased AMP-activated protein kinase activity without attenuation of the mitochondrial electron transport chain activities. Metformin treatment resulted in lower chronic inflammation and increased antioxidant protection, suggesting that the ability of metformin to improve health of laboratory animals may stem from these factors. Our results support that metformin supplementation could be beneficial in extending health and lifespan in humans.
Project description:Objective: To investigate the effects of metformin on intestinal carbohydrate metabolism in vivo.
Method: Male mice preconditioned with a high-fat, high-sucrose diet were treated orally with metformin or a control solution for two weeks. Fructose metabolism, glucose production from fructose, and production of other fructose-derived metabolites were assessed using stably labeled fructose as a tracer.
Results: Metformin treatment decreased intestinal glucose levels and reduced incorporation of fructose-derived metabolites into glucose. This was associated with decreased intestinal fructose metabolism as indicated by decreased enterocyte F1P levels and diminished labeling of fructose-derived metabolites. Metformin also reduced fructose delivery to the liver. Proteomic analysis revealed that metformin coordinately down-regulated proteins involved carbohydrate metabolism including those involved in fructolysis and glucose production within intestinal tissue.
Conclusion: Metformin reduces intestinal fructose metabolism, and this is associated with broad-based changes in intestinal enzyme and protein levels involved in sugar metabolism indicating that metformin's effects on sugar metabolism are pleiotropic.
Project description:Background: Metformin, one of the first-line medication for the treatment of type 2 diabetes and gestational diabetes, has recently be suggested for targeting cardiovascular disease, cancer and aging. Therefore, current understanding of the mechanism of this drug is incompletely understood, and the function of multiple tissues, other than liver metabolism alone, may be influenced. Methods: The wildtype healthy mice treated with metformin were compared with controls (treated with double distilled water). The transcriptome changes with/without metformin treatment were probed by using high-throughput RNA-seq techniques Results: A comprehensive mouse transcriptome map with metformin treatment across ten tissues including aorta, eyeball, brain, adipose tissue, heart, kidney, liver, skeletal muscle, stomach and testis, was provided. Function enrichment, network characteristics and disease association of the differentially expressed genes were analyzed. We also compared our expression profiles with related microarray data in order to find conditions that share similar expression profiles with metformin treatment. Conclusions: This dataset could serve as a baseline resource for investigating the potential beneficial or adverse effects of metformin across different tissues.
Project description:The microRNAs expression was altered with the treatment of metformin in vivo and several microRNAs induced by metformin also may contribute to suppressed of NASH. Using a custom microarray platform, we analyzed the expression levels of 1135 mouse microRNA probes in liver tissue in vivo that were treated with and without metformin.