Biology subjects

Mauvais-Jarvis, F.

Publications and source records attributed to Mauvais-Jarvis, F..

5 recordsLinked to original sources

bioRxiv2025

Supervised machine learning identifies impaired mitochondrial quality control in β cells with development of type 2 diabetes

In type 2 diabetes (T2D), molecular pathways driving {beta} cell failure are difficult to resolve with standard single cell analysis. Here we developed an interpretable, supervised machine learning framework that couples sparse rule-based classification (SnakeClassifier), pathway constrained modelling (BlackSwanClassifier), and {beta} cell mitochondrial fitness stratification (Kolmogorov-Arnold Neural Networks KANN), linking and integrating them into disease mechanisms in single cell RNA sequencing (scRNA-seq) from 52 human donors. SnakeClassifier trained on 50 genes accurately predicted T2D at single cell resolution, outperforming classical ensemble machine learning classifier models, and yielded donor level diabetes scores that correlated with chronic hyperglycemia. The clustering of {beta} cell populations ({beta}1-4) revealed a resilient non-diabetic (ND) {beta}1 subtype characterized by preserved {beta} cell identity genes and lower disease risk, whereas T2D {beta}2-4 subtypes exhibited upregulation of genes involved in cellular and mitochondrial stress and suppression of genes promoting oxidative phosphorylation and insulin secretion. Mitophagy emerged as the dominant program linked to T2D and a mitophagy focused BlackSwanClassifier nominated PINK1, BNIP3, and FUNDC1 as key regulators. PINK1 was enriched in ND {beta}1, decreased with T2D disease score and connected sex stratified mitophagy. We generated a KANN derived mitochondrial fitness index (MFI) integrating mitophagy, mitochondrial proteostasis, biogenesis and oxidative phosphorylation into a single interpretable score (R2 = 0.934 vs module-based mitochondria quality index), which identified mitophagy PINK1, SQSTM1, PRKN and BNIP3 as top contributors to T2D progression. These transparent models unify prediction with T2D disease mechanism and identify the mitophagy receptor PINK1 as a central determinant of {beta} cell metabolic fitness

systems biology↗

bioRxiv2024

Single cell regulatory architecture of human pancreatic islets suggests sex differences in β cell function and the pathogenesis of type 2 diabetes.

Biological sex affects the pathogenesis of type 2 and type 1 diabetes (T2D, T1D) including the development of {beta} cell failure observed more often in males. The mechanisms that drive sex differences in {beta} cell failure is unknown. Studying sex differences in islet regulation and function represent a unique avenue to understand the sex-specific heterogeneity in {beta} cell failure in diabetes. Here, we examined sex and race differences in human pancreatic islets from up to 52 donors with and without T2D (including 37 donors from the Human Pancreas Analysis Program [HPAP] dataset) using an orthogonal series of experiments including single cell RNA-seq (scRNA-seq), single nucleus assay for transposase-accessible chromatin sequencing (snATAC-seq), dynamic hormone secretion, and bioenergetics. In cultured islets from nondiabetic (ND) donors, in the absence of the in vivo hormonal environment, sex differences in islet cell type gene accessibility and expression predominantly involved sex chromosomes. Of particular interest were sex differences in the X-linked KDM6A and Y-linked KDM5D chromatin remodelers in female and male islet cells respectively. Islets from T2D donors exhibited similar sex differences in differentially expressed genes (DEGs) from sex chromosomes. However, in contrast to islets from ND donors, islets from T2D donors exhibited major sex differences in DEGs from autosomes. Comparing {beta} cells from T2D and ND donors revealed that females had more DEGs from autosomes compared to male {beta} cells. Gene set enrichment analysis of female {beta} cell DEGs showed a suppression of oxidative phosphorylation and electron transport chain pathways, while male {beta} cell had suppressed insulin secretion pathways. Thus, although sex-specific differences in gene accessibility and expression of cultured ND human islets predominantly affect sex chromosome genes, major differences in autosomal gene expression between sexes appear during the transition to T2D and which highlight mitochondrial failure in female {beta} cells.

genomics↗

bioRxiv2023

Sex-specific actions of estradiol and testosterone on human fibroblast and endothelial cell proliferation, bioenergetics, and vasculogenesis

Progress toward the development of sex-specific tissue engineered systems has been hampered by the lack of research efforts to define the effects of sex-specific hormone concentrations on relevant human cell types. Here, we investigated the effects of defined concentrations of estradiol (E2) and dihydrotestosterone (DHT) on primary human dermal and lung fibroblasts (HDF and HLF), and human umbilical vein endothelial cells (HUVEC) from female (XX) and male (XY) donors in both 2D expansion cultures and 3D stromal vascular tissues. Sex-matched E2 and DHT stimulation in 2D expansion cultures significantly increased the proliferation index, mitochondrial membrane potential, and the expression of genes associated with bioenergetics (Na+/K+ ATPase, somatic cytochrome C) and beneficial stress responses (chaperonin) in all cell types tested. Notably, cross sex hormone stimulation, i.e., DHT treatment of XX cells in the absence of E2 and E2 stimulation of XY cells in the absence of DHT, decreased bioenergetic capacity and inhibited cell proliferation. We used a microengineered 3D vasculogenesis assay to assess hormone effects on tissue scale morphogenesis. E2 increased metrics of vascular network complexity compared to vehicle in XX tissues. Conversely, and in line with results from 2D expansion cultures, E2 potently inhibited vasculogenesis compared to vehicle in XY tissues. DHT did not significantly alter vasculogenesis in XX or XY tissues but increased the number of non-participating endothelial cells in both sexes. This study establishes a scientific rationale and adaptable methods for using sex hormone stimulation to develop sex-specific culture systems.

bioengineering↗

bioRxiv2021

Hepatocyte androgen receptor in females mediates androgen-induced hepatocellular glucose mishandling and systemic insulin resistance

Androgen excess is one of the most common endocrine disorders of reproductive-aged women, affecting up to 20% of this population. Women with elevated androgens often exhibit hyperinsulinemia and insulin resistance. The mechanisms of how elevated androgens affect metabolic function are not clear. Hyperandrogenemia in a dihydrotestosterone (DHT)-treated female mouse model induces whole body insulin resistance possibly through activation of the hepatic androgen receptor (AR). We investigated the role of hepatocyte AR in hyperandrogenemia-induced metabolic dysfunction by using several approaches to delete hepatic AR via animal-, cell-, and clinical-based methodologies. We conditionally disrupted hepatocyte AR in female mice developmentally (LivARKO) or acutely by tail vein injection of an adeno-associated virus with a liver-specific promoter for Cre expression in ARfl/fl mice (adLivARKO). We observed normal metabolic function in littermate female Control (ARfl/fl) and LivARKO (ARfl/fl; Cre+/-) mice. Following chronic DHT treatment, female Control mice treated with DHT (Con-DHT) developed impaired glucose tolerance, pyruvate tolerance, and insulin tolerance, not observed in LivARKO mice treated with DHT (LivARKO-DHT). Further, during an euglycemic hyperinsulinemic clamp, the glucose infusion rate was improved in LivARKO-DHT mice compared to Con-DHT mice. Liver from LivARKO, and primary hepatocytes derived from LivARKO, and adLivARKO mice were protected from DHT-induced insulin resistance and increased gluconeogenesis. These data support a paradigm in which elevated androgens in females disrupt metabolic function via hepatic AR and insulin sensitivity was restored by deletion of hepatic AR.

molecular biology↗

bioRxiv2020

Testosterone enhances GLP-1 efficacy at the plasma membrane and endosomes to augment insulin secretion in male pancreatic β cells

Male mice with elimination of the androgen receptor (AR) in islet {beta} cells ({beta}ARKO) exhibit blunted glucose-stimulated insulin secretion (GSIS), leading to hypoinsulinemia and hyperglycemia when challenged with a Western diet. Testosterone activation of an extranuclear AR in {beta} cells potentiates GSIS by amplifying the insulinotropic action of glucagon-like peptide-1 (GLP-1). Here, using a combination of {beta}ARKO and {beta} cell-selective GLP-1 receptor knockout mice and their islets, we show that AR activation in {beta} cells amplifies the insulinotropic effect of islet-derived GLP-1. In {beta} cell models expressing cAMP sensors, testosterone enhances the ability of GLP-1, but not that of glucose-dependent insulinotropic polypeptide or glucagon, to produce cAMP. Accordingly, testosterone selectively enhances the ability of GLP-1 to potentiate GSIS. Notably, testosterone enhances GLP-1 production of cAMP at the plasma membrane and endosomes. In male mouse and human islets, the insulinotropic effect of testosterone is abolished following inhibition of the membrane and endosomal cAMP-dependent protein kinase A and exchange protein activated by cAMP islet 2 pathways. Thus, membrane localization of AR enhances the ability of the GLP-1 receptor to produce cAMP, thus increasing glucose-stimulated insulin exocytosis. Significance StatementThis study reveals that testosterone, acting on the androgen receptor (AR) in insulin-producing {beta} cells amplifies the insulinotropic action of glucagon-like peptide-1 (GLP-1) by increasing GLP-1-mediated production of cAMP at the plasma membrane and endosomal compartments, to promote insulin vesicles exocytosis in human {beta} cells. This study establishes a novel biological paradigm in which membrane location of a steroid nuclear receptor enhances the ability of a G protein-coupled receptor to produce cAMP. It has exceptional clinical significance for targeted delivery of testosterone to {beta} cells in the large population of aging and androgen-deficient men who are at increased risk of diabetes.

physiology↗