Biology subjects

Trevisani, M.

Publications and source records attributed to Trevisani, M..

3 recordsLinked to original sources

bioRxiv2024

Transcriptomic analysis reveals lipid metabolism and macrophage involvement associated with nintedanib treatment in a rat bleomycin model

INTRODUCTIONIdiopathic pulmonary fibrosis (IPF) is a progressive and irreversible lung disease with a poor prognosis. While pirfenidone and nintedanib offer some benefits, they cannot cure IPF. Nintedanib inhibits various proliferative pathways and has antifibrotic effects, but its molecular mechanisms and impact on the lung transcriptome in vivo remain unclear. This study aims to evaluate nintedanibs transcriptomic profile in a rat model of bleomycin-induced lung fibrosis. METHODOLOGY/PRINCIPAL FINDINGSLung fibrosis was induced by two intratracheal administrations of bleomycin. Nintedanib protocol included three weeks of daily oral treatments beginning seven days after the first bleomycin dose. Left lungs were processed for histological evaluation using an automated fibrosis quantification system and the Ashcroft Score, while the right lungs were used for RNA sequencing to conduct differential expression and correlation network analysis (WGCNA). WGCNA modules were examined by cell and pathway enrichment analysis. Lipid peroxidation was assessed through the measurement of malondialdehyde in right lung lysates. Bleomycin induced significant fibrotic lesions, as confirmed by the histological evaluations. Nintedanib reduced fibrotic lesion size by about 15% and decreased severe Ashcroft scores. When compared to controls, the number of differentially expressed genes decreased from over 2000 to barely more than 400 after nintedanib treatment. WGCNA identified two gene clusters correlated to histological parameters, with nintedanib-treated animals showing gene expression levels similar to control animals. One cluster was associated with mesenchymal cells and extracellular matrix-related pathways, in line with the known anti-fibrotic effect of nintedanib. The second cluster, involving principally macrophages, was related to lipid metabolism, potentially uncovering a new mechanistic role of nintedanib in modulating lung fibrosis. CONCLUSIONS/SIGNIFICANCEThe mechanisms involving macrophages and lipid metabolism, influenced by nintedanib in this study, may open new research directions to better inquire the role of this cellular type in tissue repair and pathological lung fibrosis.

pharmacology and toxicology↗

bioRxiv2024

A claudin5-binding peptide enhances the permeability of the blood-brain-barrier

The blood-brain barrier (BBB) is essential to maintain brain homeostasis and healthy conditions but it also prevents drugs from reaching brain cells. In the BBB, tight junctions (TJs) are multi-protein complexes located at the interface between adjacent brain endothelial cells that regulate paracellular diffusion and claudin-5 (CLDN5) is the major component of the TJ portfolio, playing a pivotal role in restricting the paracellular traffic. In view of obtaining fine control over the transport across the BBB, the use of competing peptides able to bind CLDN5 to induce transient and regulated permeabilization of the paracellular passage is emerging as a potentially translatable strategy for clinical applications. In this work, we designed and tested short peptides with improved solubility and biocompatibility using a combined approach that involved structural modeling techniques and in vitro validation, generating a robust workflow for the design, screening, and optimization of peptides for the modulation of the BBB paracellular permeability. We designed a selection of 11- to 16-mer compounds derived from the first CLDN5 extracellular domain and from the CLDN5-binding domain of Clostridium perfringens enterotoxin and determined their efficiency in enhancing BBB permeability. The computational analysis classified all tested peptides based on solubility and affinity to CLDN5, and provided atom-level details of the binding process. From our screening, we identified a novel CLDN5-derived peptide, here called f1-C5C2, which demonstrated good solubility in biological media, efficient binding to CLDN5 subunits, and capability to increase permeability at low concentrations. The peptidomimetic in silico/in vitro strategy described here can achieve a transient and reversible permeabilization of the BBB with potential applications in the pharmacological treatment of brain diseases. HIGHLIGHTSO_LIWater-soluble peptidomimetics are used to competitively bind claudin-5 tight junction proteins and increase the permeability of the blood-brain barrier; C_LIO_LITrans-endothelial electrical resistance and dissociation constant measurements demonstrate the binding affinity of the peptide f1-C5C2 for claudin-5; C_LIO_LIUnbinding free energy calculations correlated with experimental results and provided information on the protein-peptide binding interface. C_LIO_LIIncubation with the peptide f1-C5C2 allows paracellular transport of 4K, but not 70K, dextran. C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/591687v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@70fe54org.highwire.dtl.DTLVardef@496a28org.highwire.dtl.DTLVardef@1d89a81org.highwire.dtl.DTLVardef@187acec_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Pyruvate metabolism dictates fibroblast sensitivity to GLS1 inhibition during fibrogenesis

Fibrosis is a chronic disease characterized by excessive extracellular matrix (ECM) production which leads to destruction of normal tissue architecture and disruption of organ function. Fibroblasts are key effector cells of this process and respond to a host of pro-fibrotic stimuli, including notably the pleiotropic cytokine, TGF-{beta}1, which promotes fibroblast to myofibroblast differentiation. This is accompanied by the simultaneous rewiring of metabolic networks to meet the biosynthetic and bioenergetic needs of contractile and ECM-synthesizing cells, but the exact mechanisms involved remain poorly understood. In this study, we report that extracellular nutrient availability profoundly influences the TGF-{beta}1 transcriptome of primary human lung fibroblasts (pHLFs) and the "biosynthesis of amino acids" emerges as a top enriched transcriptional module influenced by TGF-{beta}1. We subsequently uncover a key role for pyruvate in influencing the pharmacological impact of glutaminase (GLS1) inhibition during TGF-{beta}1-induced fibrogenesis. In pyruvate replete conditions which mimic the physiological concentration of pyruvate in human blood, GLS1 inhibition is ineffective in blocking TGF-{beta}1-induced fibrogenesis, as pyruvate is able to be used as the substrate for glutamate and alanine production via glutamate dehydrogenase (GDH) and glutamic-pyruvic transaminase 2 (GPT2), respectively. We further show that dual targeting of either GPT2 or GDH in combination with GLS1-inhibition is required to fully block TGF-{beta}1-induced collagen synthesis. These findings embolden a therapeutic strategy aimed at additional targeting of mitochondrial pyruvate metabolism in the presence of a glutaminolysis inhibitor in order to interfere with the pathological deposition of collagen in the setting of pulmonary fibrosis and potentially other fibrotic conditions.

cell biology↗