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Nadal, A.

Publications and source records attributed to Nadal, A..

8 recordsLinked to original sources
bioRxiv2025

Increased TGFβ /Activin-Smad2 signaling is associated with pancreatic β-cell dysfunction and glucose intolerance in gestational diabetes mellitus

BackgroundGestational diabetes mellitus (GDM) is the most common metabolic disease during pregnancy and increases the prevalence of type 2 diabetes in both mothers and offspring. GDM management provides a window of opportunity to prevent and lower the global burden of diabetes across life. Molecular mechanisms underlying GDM are poorly defined. In this study, we explore the potential involvement of transforming growth factor beta (TGF-{beta}) signaling in GDM as this pathway has been reported to affect pancreatic {beta}-cell development, proliferation and identity. MethodsWe developed a GDM animal model. Serum circulating levels of TGF{beta} family ligands were measured in mice and human GDM. Pancreatic TGF{beta} signaling was investigated at the level of gene and protein expression. ResultsOur GDM animal model recapitulates the main pathophysiological features of human GDM including glucose intolerance, decreased insulin sensitivity and pancreatic {beta}-cell malfunction. Islets from GDM mice showed impaired insulin secretion and content, altered ion channel activity, and decreased {beta}-cell replication rate. This was accompanied by increased Smad2 signaling activation. Elevated serum activin-A and inhibin levels were found in mice and human GDM, suggesting their role as upstream signaling transducers of pancreatic Smad2 activation. Pharmacological inhibition of TGF{beta}/Activin-Smad2 signaling in mouse pancreatic islets resulted in improved pancreatic {beta}-cell function and regeneration capacity of {beta}-cells. ConclusionsOur data disclose that disruption of pancreatic Smad2 pathway plays a critical role in the pathogenesis of GDM, contributing to abnormal glucose homeostasis and inadequate insulin secretion. Attenuation of this signaling pathway could represent a putative therapeutic target for GDM. HighlightsO_LIHigh fat diet just before and during pregnancy leads to gestational diabetes in mice. C_LIO_LIActivin and inhibin serum levels are increased in human and mice gestational diabetes. C_LIO_LIEnhanced pancreatic Smad2 signaling contributes to inadequate insulin secretion in gestational diabetes. C_LIO_LIInhibition of Smad2 signaling improves pancreatic {beta}-cell function and proliferation. C_LI

physiology↗
bioRxiv2022

Deucravacitinib, a tyrosine kinase 2 pseudokinase inhibitor, protects human beta cells against proinflammatory insults

Aims/hypothesisType 1 diabetes is characterised by pancreatic islet inflammation and autoimmune-driven pancreatic beta cell destruction. Type I interferons, such as IFN, are key players in early human type 1 diabetes pathogenesis, as the activation of the tyrosine kinase 2 (TYK2)-signal transducer and activator of transcription (STAT) pathway induces inflammation, a long-lasting MHC class I overexpression, endoplasmic reticulum (ER) stress, and beta cell apoptosis (in synergy with IL-1{beta}). As TYK2 inhibition has been suggested as a potential therapeutic target for the prevention or treatment of type 1 diabetes, we investigated whether the selective TYK2 inhibitor deucravacitinib could protect beta cells against the damaging effects of IFN and other proinflammatory cytokines (i.e. IFN{gamma} and IL-1{beta}). MethodsInflammation, ER stress, and apoptosis were evaluated by real-time PCR, immunoblot, immunofluorescence, and nuclear dyes. The promoter activity was assessed by luciferase assay and insulin secretion and content by ELISA. All experiments were performed in the human EndoC- {beta}H1 cell line. ResultsPre-treatment with deucravacitinib prevented IFN effects, such as STAT1 and STAT2 phosphorylation and protein expression as well as MHC class I hyperexpression, in a dose-dependent manner without affecting beta cell survival and function. Comparison between deucravacitinib and two Janus kinase inhibitors, ruxolitinib and baricitinib, showed that deucravacitinib blocked IFN- but not IFN{gamma}-induced signalling pathway. Pre-treatment with deucravacitinib protected beta cells from the pro-apoptotic and proinflammatory effects of two different combinations of cytokines: IFN + IL-1{beta} and IFN{gamma} + IL-1{beta}. Moreover, this TYK2 inhibitor could partially revert apoptosis and inflammation in cells previously treated with IFN + IL-1{beta} or IFN{gamma} + IL-1{beta}. Conclusions/interpretationOur findings suggest that, by protecting beta cells against the deleterious effects of proinflammatory cytokines without affecting beta cell function and survival, deucravacitinib could be repurposed for the prevention or treatment of early type 1 diabetes. Research in contextWhat is already known about this subject? O_LIIn type 1 diabetes, pancreatic beta cells are killed by the immune system C_LIO_LIIn early insulitis, type I interferons are crucial for the dialogue between the immune system and pancreatic beta cells C_LIO_LIActivation of the TYK2-STAT pathway by IFN induces inflammation, HLA class I overexpression, ER stress, and beta cell apoptosis. C_LI What is the key question? O_LICould the TYK2 inhibitor deucravacitinib prevent the deleterious effects of IFN and other cytokines in beta cells? C_LI What are the new findings? O_LIDeucravacitinib prevented IFN effects in a dose-dependent manner without affecting beta cell function and survival C_LIO_LIPre-treatment with deucravacitinib protected beta cells against apoptosis and inflammation induced by two different combinations of cytokines: IFN + IL-1{beta} and IFN{gamma} + IL-1{beta} C_LIO_LIAddition of deucravacitinib to cells pre-treated with IFN + IL-1{beta} or IFN{gamma} + IL-1{beta} partially reverted apoptosis and inflammation induced by these cytokines C_LI How might this impact on clinical practice in the foreseeable future? O_LIDue to its protective effect against proinflammatory cytokines in beta cells, our findings suggest that deucravacitinib could be repurposed for the prevention or treatment of type 1 diabetes. C_LI

cell biology↗
bioRxiv2022

Screening of metabolism-disrupting chemicals on pancreatic alpha-cells using in vitro methods

Metabolism-disrupting chemicals (MDCs) are endocrine disruptors with obesogenic and/or diabetogenic action. There is mounting evidence linking exposure to MDCs to increased susceptibility to diabetes. Despite the important role of glucagon in glucose homeostasis, there is little information on the effects of MDCs on -cells. Furthermore, there are no methods to identify and test MDCs with the potential to alter -cell viability and function. Here we used the mouse -cell line TC1-9 to evaluate the effects of MDCs on cell viability and glucagon secretion. We tested six chemicals at concentrations within human exposure (from 0.1 pM to 1 M): bisphenol-A (BPA), tributyltin (TBT), perfluorooctanoic acid (PFOA), triphenylphosphate (TPP), triclosan (TCS), and dichlorodiphenyldichloroethylene (DDE). Using two different approaches, MTT assay and DNA-binding dyes, we observed that BPA and TBT decreased -cell viability via a mechanism that depends on the activation of estrogen receptors and PPAR{gamma}, respectively. These two chemicals induced ROS production, but barely altered the expression of endoplasmic reticulum (ER) stress markers. Although PFOA, TPP, TCS, and DDE did not alter cell viability nor induced ROS generation or ER stress, all four compounds negatively affected glucagon secretion. Our findings suggest that TC1-9 cells seem an appropriate model to test chemicals with metabolism-disrupting activity and that the improvement of the test methods proposed herein could be incorporated into protocols for the screening of diabetogenic MDCs.

pharmacology and toxicology↗
bioRxiv2022

Development of in vitro test methods in a model of human pancreatic β-cells to identify metabolism disrupting chemicals with diabetogenic activity

There is a need to develop identification tests for Metabolism Disrupting Chemicals (MDCs) with diabetogenic activity. Here we used the human EndoC-{beta}H1 {beta}-cell line, the rat {beta}-cell line INS-1E and dispersed mouse islet cells to assess the effects of endocrine disruptors on cell viability and glucose-stimulated insulin secretion (GSIS). We tested six chemicals at concentrations within human exposure (from 0.1 pM to 1 M). Bisphenol-A (BPA) and tributyltin (TBT) were used as controls while four other chemicals, namely perfluorooctanoic acid (PFOA), triphenylphosphate (TPP), triclosan (TCS) and dichlorodiphenyldichloroethylene (DDE), were used as "unknowns". Regarding cell viability, BPA and TBT increased cell death as previously observed. Their mode of action involved the activation of estrogen receptors and PPAR{gamma}, respectively. ROS production was a consistent key event in BPA- and TBT-treated cells. None of the other MDCs tested modified viability or ROS production. Concerning GSIS, TBT increased insulin secretion while BPA produced no effects. PFOA decreased GSIS, suggesting that this chemical could be a "new" diabetogenic agent. Our results indicate that the EndoC-{beta}H1 cell line is a suitable human {beta}-cell model for testing diabetogenic MDCs. Optimization of the test methods proposed here could be incorporated into tier protocols for the identification of MDCs.

pharmacology and toxicology↗
bioRxiv2022

G protein-coupled oestrogen receptor activation by Bisphenol-A disrupts protection from apoptosis conferred by oestrogen receptors ERα and ERβ in pancreatic beta cells

17{beta}-estradiol protects pancreatic {beta}-cells from apoptosis via the estrogen receptors ER, ER{beta} and GPER. Conversely, the endocrine disruptor Bisphenol-A (BPA), which exerts multiple effects in this cell type via the same estrogen receptors, increased basal apoptosis. The molecular initiated events that trigger these opposite actions have yet to be identified. We demonstrated that combined genetic downregulation and pharmacological blockade of each estrogen receptor increased apoptosis to a different extent. The increase in apoptosis induced by BPA was diminished by the pharmacological blockade or the genetic silencing of GPER, and it was partially reproduced by the GPER agonist G1. BPA and G1-induced apoptosis were abolished upon pharmacological inhibition, silencing of ER and ER{beta}, or in dispersed islet cells from ER{beta} knockout (BERKO) mice. Yet, the ER and ER{beta} agonists, PPT and DPN, respectively, had no effect on beta cell viability. To exert their biological actions, ER and ER{beta} form homodimers and heterodimers. Molecular dynamic simulations together with proximity ligand assay and coimmunoprecipitation experiments indicated that the interaction of BPA with ER and ER{beta} as well as the GPER activation by G1 decreased ER{beta} heterodimers. We propose that ER{beta} heterodimers play an antiapoptotic role in beta cells and that BPA- and G1-induced decrease in ER{beta} heterodimers leads to beta cell apoptosis. Unveiling how different estrogenic chemicals affect the crosstalk among estrogen receptors should help to identify diabetogenic endocrine disruptors. HighlightsO_LIPharmacological blockade and gene silencing of estrogen receptors ER, ER{beta} and GPER indicate that they are antiapoptotic in basal conditions. C_LIO_LIGPER activation by G1 and BPA triggered apoptosis via a crosstalk with ER and ER{beta}. C_LIO_LIBPA interaction with ER and ER{beta} as well as GPER activation decreased ER{beta} heterodimers, which was associated to increased apoptosis. C_LIO_LIThis pathway represents a novel molecular initiating event underlying the pro-apoptotic effect of BPA C_LIO_LIThe EndoC-{beta}H1 cell line may be a valid model of human {beta}-cells for identifying diabetogenic pollutants. C_LI

physiology↗
bioRxiv2020

Bisphenol-S and Bisphenol-F alter mouse pancreatic β-cell ion channel expression and activity and insulin release through an estrogen receptor ERβ mediated pathway

Bisphenol-S (BPS) and Bisphenol-F (BPF) are current Bisphenol-A (BPA) substitutes. Here we used pancreatic {beta}-cells from wild type (WT) and estrogen receptor {beta} (ER{beta}) knockout (BERKO) mice to investigate the effects of BPS and BPF on insulin secretion, and the expression and activity of ion channels involved in {beta}-cell function. BPS or BPF rapidly increased insulin release and diminished ATP-sensitive K+ (KATP) channel activity. Similarly, 48 h treatment with BPS or BPF enhanced insulin release and decreased the expression of several ion channel subunits in {beta}-cells from WT mice, yet no effects were observed in cells from BERKO mice. PaPE-1, a ligand designed to preferentially trigger extranuclear-initiated ER pathways, mimicked the effects of bisphenols, suggesting the involvement of extranuclear-initiated ER{beta} pathways. Molecular dynamics simulations indicated differences in ER{beta} ligand-binding domain dimer stabilization and solvation free energy among different bisphenols and PaPE-1. Our data suggest a mode of action involving ER{beta} whose activation alters three key cellular events in {beta}-cell, namely ion channel expression and activity, and insulin release. These results may help to improve the hazard identification of bisphenols.

pharmacology and toxicology↗
bioRxiv2018

Agreement between 18F-Florbetapir PET imaging and cerebrospinal fluid Aβ1-42, Aβ1-40, tTau and pTau measured on the LUMIPULSE G fully automated platform

INTRODUCTIONThe development of fully automated immunoassay platforms has improved the technical reliability of cerebrospinal fluid (CSF) biomarkers for Alzheimers disease.\n\nMETHODSWe quantified A{beta}1-42, A{beta}1-40, tTau and pTau levels using the Lumipulse G System in 94 CSF samples from participants of the SPIN cohort with available 18F-Florbetapir imaging. Amyloid scans were assessed visually and through automated quantification. We determined the cutoffs of CSF biomarkers that optimized their agreement with 18F-Florbetapir PET and evaluated concordance between markers of the amyloid category.\n\nRESULTSA{beta}1-42, tTau and pTau (but not A{beta}1-40) and the ratios with A{beta}1-42 had good diagnostic agreement with 18F-Florbetapir PET. As a marker of amyloid pathology, the A{beta}1-42/A{beta}1-40 ratio had higher agreement and better correlation with amyloid PET than A{beta}1-42 alone.\n\nDISCUSSIONCSF biomarkers measured with the Lumipulse G System show good agreement with amyloid imaging. Combination of A{beta}1-42 with A{beta}1-40 increases the agreement between markers of amyloid pathology.

neuroscience↗