Biology subjects

Marcos, M.

Publications and source records attributed to Marcos, M..

4 recordsLinked to original sources

bioRxiv2023

Lipid network of plasma extracellular vesicles reveals sex-based differences in the lipidomic profile from patients with alcohol use disorder

Alcohol use disorder (AUD) is one of the most common psychiatric disorders, and the consumption of this substance is considered one of the main causes of preventable deaths worldwide. Lipids play a crucial functional role in cell membranes, however little is known about the role of lipids containing extracellular vesicles (EVs), as regulatory molecules and biomarkers. In this study, a highly sensitive lipidomic strategy is employed to characterize plasma EV lipid species from individuals with AUD, to evaluate differential functional roles and enzymatic activity networks to improve the knowledge of lipid metabolism in the alcohol consumption. Plasma EV lipids from female and male patients with AUD and healthy individuals were analyzed to obtain lipid differential abundance, as well as biological interpretation of LINEX2 lipidomics data, evaluating enzymatic dysregulation through an enrichment algorithm. Our results showed for the first time that females with AUD exhibit greater substrate-product changes in LPC and PC lipids, as well as phospholipases and acyltransferases activity, potentially linked to cancer progression and neuroinflammation. Conversely, males with AUD showed dysregulation in Cer and SM lipid, involving sphingomyelinases, sphingomyelin phosphodiesterase, and sphingomyelin synthase, which could be related with hepatotoxicity. Notably, females with AUD showed LION-terms associated with "positive intrinsic curvature", while males exhibited "negative intrinsic curvature, contributing to vesicle fusion processes. These methodological developments allow a better understanding of lipid metabolism and its regulatory mechanisms, which contributes not only to identify novel lipid targets, but also the discovery of sex-specific clinical biomarkers in the AUD.

pathology↗

bioRxiv2023

Lack of p38 activation in T cells increases IL-35 production and protects against obesity by promoting thermogenesis

Obesity is characterized with low grade inflammation, energy imbalance and impaired thermogenesis. The role of regulatory T cells (Treg) in inflammation-mediated maladaptive thermogenesis has not been well established. We discovered that p38 pathway is a key regulator of T cell-mediated adipose tissue (AT) inflammation and browning. Mice with T cells specific deletion of the p38 activators, MKK3/6, were protected against diet-induced obesity and AT inflammation improving their metabolic profile, higher browning and thermogenesis. We identified IL-35 as a driver of adipocyte thermogenic program through ATF2/UCP1/FGF21 pathway. IL-35 limits CD8+ T cell infiltration and inflammation in AT. Interestingly, we found that IL35 was reduced in visceral fat from obese patients. Mechanistically we showed that p38 controls the expression of IL-35 in human and mouse Treg cells through mTOR pathway activation. Our findings highlight p38 signaling as a molecular orchestrator of AT T cell accumulation and function and identify p38 and IL-35 as promising targets for metabolic diseases.

immunology↗

bioRxiv2022

The immunodominant protein P116 is a passive transporter of cholesterol and other essential lipids

Many human pathogens need to extract lipids from their environment for survival and proliferation. How this is accomplished on a molecular level is largely unknown1. Here, we report a comprehensive structural and functional analysis of the previously uncharacterized protein P116 (MPN_213) from Mycoplasma pneumoniae, a human pathogen responsible for approximately 30% of community-acquired human pneumonia2. Single-particle cryo-electron microscopy of P116 at 3.3 [A] resolution reveals a homodimer with a core domain presenting a previously unseen fold. This fold creates a large cavity of [~]18,000 [A]3 with a hydrophobic internal surface that is accessible to solvent. Within the cavity ligands with a length of 10-19 [A] and a width of 4 [A] could be observed. These ligands were identified as the essential lipids phosphatidylcholine, sphingomyelin and cholesterol using mass spectrometry. When the cavity is emptied, the protein undergoes an extensive conformational change that can no longer accommodate lipids. When emptied P116 is incubated with high-density lipoproteins (HDLs) a net transfer of cholesterol is demonstrated by a radioactivity experiment and cryo-electron microscopy resolves a complex between P116 and HDL. Taken together, our results reveal the mechanism by which P116 extracts essential lipids from the host environment and possibly then delivers them into the membrane by a wringing movement. This mechanism may be precedential for other cholesterol-auxotrophic bacteria.

microbiology↗

bioRxiv2019

Rituximab treatment for IgA vasculitis: A systematic review

ObjetivesImmunoglobulin A vasculitis (IgAV) is an inflammatory disease with a controversial treatment based in corticosteroids as first line. To review cases of patients with IgA vasculitis (IgAV) treated with rituximab (RTX) and assess disease characteristics, treatment efficacy and safety.\n\nMethodsWe conducted a systematic literature review according to PRISMA guidelines. We searched Pubmed, Web of Science, Embase and Scopus, selecting articles with information on IgAV and RTX treatment up to February 2019, with no language limitations. We extracted data on patient characteristics, disease evolution, treatment safety and efficacy. We created a database and analyzed it using statistical software package SPSS v 22.0.\n\nResultsWe extracted clinical data for 43 IgAV patients treated with RTX. Distribution by sex was similar, and the median age at diagnosis was 16 (range 2 months to 70 years). The majority of patients were diagnosed at a pediatric age (24 patients under 18, 55.81%). The time of disease evolution until RTX administration greatly varied. An important number of patients suffered renal complications (86%) before RTX treatment. The frequency of adverse effects from RTX was low (7%, hypersensitivity with no treatment interruption). In terms of disease evolution, 41 patients (95.3%) presented clinical improvement, 15 patients had recurrence after initial remission (34.9%) and 34 patients (79.1%) achieved full remission after completing treatment. None of the patients treated with RTX and included in our systematic review died.\n\nConclusionsRTX is efficacious in patients with IgAV. A high percentage of patients achieved complete remission with a favorable safety profile.

pharmacology and toxicology↗