Biology subjects

Monroy, F.

Publications and source records attributed to Monroy, F..

6 recordsLinked to original sources

bioRxiv2025

Metabolic Rigidity as a Mechanical Barrier to Malaria: Flickering Loss in PKLR-Deficient Erythrocytes

Pyruvate kinase (PK) deficiency is a rare hereditary enzymopathy caused by mutations in the PKLR gene, leading to reduced glycolytic ATP production in red blood cells (RBCs) and contributing to chronic hemolytic anemia. Here, we use high-speed flickering spectroscopy and passive microrheology to assess how ATP depletion reshapes the nanomechanical properties of RBC membranes. Compared to healthy controls, PKLR-mutant erythrocytes exhibit marked reductions in ATP-dependent flickering amplitude and membrane fluidity, consistent with impaired metabolic elasticity. Strikingly, when infected with Plasmodium yoelii, these metabolically rigidified cells retain mechanical properties that appear to hinder parasite-induced membrane remodeling. By mapping single-cell viscoelastic landscapes across healthy, mutated, infected and coinfected mouse RBC populations, we uncover a potential biomechanical barrier against malaria imposed by glycolytic insufficiency. These findings highlight a mechanobiological axis of host resistance and position label-free flickering analysis as a powerful tool for diagnosing RBC enzymopathies and probing infection susceptibility at the single-cell level.

biophysics↗

bioRxiv2023

Dual mechanical impact of β-escin on model lipid membranes

Using artificially reconstituted membranes based on structurally liquidlike phospholipids, we have performed an experimental study on the mechanical impact of the saponin {beta}-aescin, aka escin, a natural biosurfactant extracted from the seeds of the horse chestnut tree Aesculus hippocastanum. The paper focusses on the modulable interaction of escin with DMPC in model membranes in the form of bilayer vesicles and Langmuir monolayers. As regarding to their dual mechanical membrane behavior being both soft solids and viscoelastic fluids, we have outlined the principal energetic and kinetic features describing the insertion of escin as transversally adsorbed or longitudinally integrated within the model membranes. At connection with the structural phase behavior assessed by dedicated microscopies of surface fluorescence and Brewster angle reflectivity, these hybrid escin / phospholipid membranes have been revealed to possess dual mechanical properties connected to their structural rigidness and fluidity behaving both in one way and another. In particular, we observe a soft glassy rheology typical for liquid-crystalline ordered phases at low temperature, which turns into a fluidlike viscoelasticity characteristic of the disordered phases at high physiological temperature. These original results have been discussed in a physicochemical perspective that may pave new avenues of material engineering and / or pharmacological design exploiting the dual mechanical impact of escin as a mechanical modulator of the cellular membrane.

biophysics↗

bioRxiv2023

3D environment modulates persistent lamin distribution and the biomechanical signature of the nucleus.

The interplay between cells and their surrounding microenvironment drives multiple cellular functions, including migration, proliferation, and cell fate transitions. The nucleus is a mechanosensitive organelle that adapts external mechanical and biochemical signals provided by the environment into nuclear changes with functional consequences for cell biology. However, the morphological and functional changes of the nucleus induced by 3D extracellular signals remain unclear. Here, we demonstrated that cells derived from 3D conditions conserve changes from cell confinement and show an aberrant nuclear morphology and localization of lamin B1, even in the absence of cellular confinement. We found that actin polymerization and protein kinase C (PKC) activity mediate the abnormal distribution of lamin B1 in 3D conditions-derived cells. These cells present altered chromatin compaction, gene transcription and cellular functions such as cell viability and migration. By combining biomechanical techniques and single-nucleus analysis, we have determined that the nucleus from 3D conditions-derived cells shows a different mechanical behavior and biophysical signature than the nucleus from control cells. Together, our work substantiates novel insights into how the extracellular environment alters the cell biology by promoting permanent changes in the chromatin, morphology, lamin B1 distribution, and the mechanical response of the nucleus.

cell biology↗

bioRxiv2023

Persistent confined migration confers permanent nuclear and functional changes in migrating cells.

Nuclear deformability plays a critical role in cell migration. During this process, the remodeling of internal components of the nucleus has a direct impact on DNA damage and cell behavior; however, how persistent migration promotes nuclear changes leading to phenotypical and functional consequences remains poorly understood. Here, we described that the persistent migration through physical barriers was sufficient to promote permanent modifications in migratory-altered cells. We found that lamin B1 altered its localization, concomitant with morphological and transcriptional changes. Migratory-altered cells showed alterations in cellular functions such as DNA repair and cell migration. We applied biochemical and biophysical approaches to identify that confined conditions altered the biomechanical response of the nucleus. Mechanistically, we determined that actin dynamics controlled the redistribution of lamin, and the basal levels of DNA damage in migratory-altered cells. Our observations reveal a novel role for confined cell conditions in consistent nuclear and genomic alterations that might handle the genetic instability and cellular heterogeneity in aging diseases and cancer. HighlightsO_LIPersistent confined migration promotes permanent mophological changes. C_LIO_LILamin B1 is redistribution in the nucleus of migratory altered cells. C_LIO_LIMigratory-altered cells exhibit transcriptional and functional changes related to cell migration and survival. C_LIO_LIActin polymerization controls nuclear changes induced by cell migration. C_LI

cell biology↗

bioRxiv2022

Highly-multiplexed serology for non-human mammals

Emerging infectious diseases represent a serious and ongoing threat to humans. Most emerging viruses are maintained in stable relationships with other species of animals, and emergence within the human population results from cross-species transmission. Therefore, if we want to be prepared for the next emerging virus, we need to broadly characterize the diversity and ecology of viruses currently infecting other animals (i.e., the animal virosphere). High-throughput metagenomic sequencing has accelerated the pace of virus discovery. However, molecular assays can only detect active viral infections and only if virus is present within the sampled fluid or tissue at the time of collection. In contrast, serological assays measure long-lived antibody responses to infections, which can be detected within the blood, regardless of the infected tissues. Therefore, serological assays can provide a complementary approach to understanding the circulation of viruses, and while serological assays have historically been limited in scope, recent advancements allow 1000s to 100,000s of antigens to be assessed simultaneously using <1 l of blood (i.e., highly-multiplexed serology). Application of highly-multiplexed serology for characterization of the animal virosphere is dependent on the availability of reagents that can be used to capture or label antibodies of interest. Here, we demonstrate the potential for commercial immunoglobulin-binding proteins (protein A and protein G) to enable highly-multiplexed serology in 25 species of non-human mammals and we describe a competitive FLISA assay that can be used as an initial screen for choosing the most appropriate capture protein for a given host species. ImportanceAntibodies are generated in response to infections with viruses and other pathogens and they help protect against future exposures. Mature antibodies are long-lived, highly specific, and can bind to their protein targets with high affinity. Thus, antibodies can also provide information about an individuals history of viral exposures, which has important applications in understanding the epidemiology and etiology of disease. In recent years, there have been large advances in the available methods for broadly characterizing antibody binding profiles, but thus far, these have primarily been utilized only with human samples. Here, we demonstrate that commercial antibody-binding reagents can facilitate modern antibody assays for a wide variety of mammalian species, and we describe a cheap and fast approach for choosing the best reagent for each animal species. By studying antibody-binding profiles in captive and wild animals, we can better understand the distribution and prevalence of viruses that could spillover into humans.

immunology↗

bioRxiv2018

A Mouse Model Of Binge Alcohol Consumption and Burkholderia Infection

BackgroundBinge drinking, a common form of alcohol consumption, is associated with increased mortality and morbidity; yet, its effects on the immune systems ability to defend against infectious agents are poorly understood. Burkholderia pseudomallei, the causative agent of melioidosis can occur in healthy humans, yet binge alcohol use is progressively being recognized as a major risk factor. Although our previous studies demonstrated that binge alcohol exposure results in reduced alveolar macrophage function and increased Burkholderia virulence in vitro, no experimental studies have investigated the outcomes of binge alcohol on Burkholderia spp. infection in vivo.\n\nPrincipal FindingsWe used the close genetic relatives of B. pseudomallei, B. thailandensis E264 and B. vietnamiensis, as useful BSL-2 model systems. Eight-week-old female C57BL/6 mice were administered alcohol comparable to human binge drinking episodes (4.4 g/kg) or PBS intraperitoneally 30 min before a non-lethal intranasal infection. In an initial B. thailandensis infection (3 x 105), bacteria accumulated in the lungs and disseminated to the spleen in alcohol administered mice only, compared with PBS treated mice at 24 h post-infection (PI). The greatest bacterial load occurred with B. vietnamiensis (1 x 106) in lungs, spleen, and brain tissue by 72 h PI. Pulmonary cytokine expression (TNF-, GM-CSF) decreased, while splenic cytokine (IL-10) increased in binge drunk mice. Increased lung and brain permeability was observed as early as 2 h post alcohol administration in vivo. Trans-epithelial electrical resistance (TEER) was significantly decreased, while intracellular invasion of non-phagocytic cells increased with 0.2% v/v alcohol exposure in vitro.\n\nConclusionsOur results indicate that a single binge alcohol dose suppressed innate immune functions and increased the ability of less virulent Burkholderia strains to disseminate through increased barrier permeability and intracellular invasion of non-phagocytic cells.\n\nAuthor SummaryBurkholderia pseudomallei causes the disease melioidosis, which occurs in most tropical regions across the globe. Exposure rarely evolves to significant disease in the absence of specific comorbidities, such as binge alcohol intoxication. In susceptible hosts, the disease is primarily manifested as pneumonic melioidosis and can be rapidly fatal if untreated. In this study, we utilized B. thailandensis, a genetically similar strain to B. pseudomallei, and opportunistic B. vietnamiensis, a known human pathogen that utilizes similar virulence strategies as B. pseudomallei in immunocompromised and cystic fibrosis patients. The study investigates the impact of a single binge alcohol episode on infectivity and immune response in vivo. We show that a single binge alcohol episode prior to inhaling Burkholderia species increases bacterial spread to the lungs and brain. We also identify alcohol-induced tissue permeability and epithelial cell invasion as modes of action for greater bacterial spread and survival inside the host. Our results support the public health responses being developed in melioidosis-endemic regions that emphasize the nature of binge drinking as a prime concern, especially around potential times of exposure to environmental B. pseudomallei.

immunology↗