Biology subjects

Munoz, I.

Publications and source records attributed to Munoz, I..

8 recordsLinked to original sources

bioRxiv2025

Dissecting the molecular basis underlying mycobacterial cell-wall hydrolysis by the catalytic domains of D29LysA and DS6ALysA phage endolysins

Mycobacteria encompass a broad range of microorganisms that cause infections with a significant impact on human health, resulting in millions of deaths each year. From tuberculosis and leprosy, caused by Mycobacterium tuberculosis and Mycobacterium leprae, respectively, to infections caused by emerging/opportunistic pathogens such as Mycobacterium abscessus. The battle to combat this health burden is further challenged by limitations in the treatments currently available and the rise of antimicrobial resistance. This underscores the need for new therapeutic strategies to combat these infections. Mycobacteriophage LysA endolysins are complex, multi-domain peptidoglycan hydrolases with reported antimicrobial relevance and the potential to treat mycobacterial infections. However, despite the therapeutic prospects of LysAs, our understanding of their mechanism of action remains limited. This study provides a comprehensive structural-functional analysis of the catalytic domains of two LysA endolysins encoded by the bacteriophages D29 and DS6A, which are known to infect pathogenic mycobacteria, including M. tuberculosis. As part of this work, we have characterized the four catalytic domains present in both endolysins (D29N4/D29GH19 and DS6AGH19/DS6AAmi2B) both alone and in complex with PG analogues. To achieve this, we combined protein engineering, X-ray crystallography, small-angle X-ray scattering, and in silico tools. To our knowledge, this has led to the first experimental structures reported for mycobacteriophage endolysins, which reveals key aspects of peptidoglycan binding and hydrolysis by D29LysA and DS6ALysA lysins, as well as other homologous LysAs, including the hydrolase domains similar to those examined here. Altogether, this represents a significant step forward in understanding how mycobacterial cell-wall hydrolysis occurs by this important class of endolysins and opens the door to their future use in therapeutic applications as enzybiotics. Information that will allow the rational design of a la carte enzymes with optimized lytic properties against mycobacterial pathogens.

biochemistry↗

bioRxiv2024

Etrinabdione (VCE-004.8), a B55a activator, promotes angiogenesis and arteriogenesis in critical limb ischemia.

BackgroundVasculogenic therapies explored for the treatment of peripheral artery disease (PAD) have encountered minimal success in clinical trials. Addressing this, B55, an isoform of protein phosphatase 2A (PP2A), emerges as pivotal in vessel remodeling through activation of hypoxia-inducible factor 1 (HIF-1). This study delves into the pharmacological profile of VCE-004.8 (Etrinabdione) and evaluates its efficacy in a preclinical model of critical limb ischemia, with a focus on its potential as a PP2A/B55 activator to induce angiogenesis and arteriogenesis. MethodsVascular endothelial cells were used for in vitro experiments. Aorta ring assay was performed to explore sprouting activity. Matrigel plug-in assay was used to assess the angiogenic potential. Critical limb ischemia (CLI) in mice was induced by double ligation in the femoral arteria. Endothelial vascular and fibrotic biomarkers were studied by immunohistochemistry and qPCR. Arteriogenesis was investigated by microvascular casting and micro-CT. Proteomic analysis in vascular tissues was analyzed by LC-MS/MS. Ex-vivo expression of B55 and biomarkers were investigated in artery samples from PAD patients. ResultsVCE-004.8 exhibited the ability to induce B55 expression and activate the intersecting pathways B55/AMPK/Sirtuin 1/eNOS and B55/PHD2/HIF-1. VCE-004.8 prevented OxLDL and H2O2-induced cytotoxicity, senescence, and inflammation in endothelial cells. Oral VCE-004.8 increased aorta sprouting in vitro and angiogenesis in vivo. In CLI mice VCE-004.8 improved collateral vessel formation and induced endothelial cells proliferation, angiogenic gene expression and prevented fibrosis. The expression of B55, Caveolin 1 and Sirtuin-1 is reduced in arteries from CLI mice and PAD patient, and the expression of these markers was restored in mice treated with VCE-004.8. ConclusionsThe findings presented in this study indicate that Etrinabdione holds promise in mitigating endothelial cell damage and senescence, while concurrently fostering arteriogenesis and angiogenesis. These observations position Etrinabdione as a compelling candidate for the treatment of PAD, and potentially other cardiovascular disorders. Novelty and SignificanceO_ST_ABSWhat Is Known?C_ST_ABSO_LIThe phosphatase PPA2/B55 stabilizes endothelial cells (ECs) in response to cell stress conditions, thereby protecting ECs from apoptosis and promoting angiogenesis. C_LIO_LIEtrinabdione (VCE-004.8) functions as a potent activator of PPA2/B55 inducing PHD2 dephosphorylation at ser125 and fostering HIF activation. C_LIO_LIVCE-004.8 prevents vascular damage in preclinical models of systemic and cardiac fibrosis and alleviates blood-brain barrier disruption in neuroinflammatory conditions. C_LIO_LIVCE-004.8 is also a dual agonist of PPAR{psi} and CB2 receptors and shows antiinflammatory activity. C_LIO_LIOral VCE-004.8 has meet the primary endpoints of safety and tolerability in a Phase IIa clinical trial with systemic sclerosis patients (clinicaltrial.gov: NCT03745001). C_LI What New Information Does This Article Contribute?O_LIEtrinabdione induces HIF-1 expression in endothelial cells through a novel pathway that potentially involves two axes: B55/PHD2 and B55/AMPK/Sirt1 signaling that may converge on HIF stabilization. C_LIO_LIEtrinabdione prevented endothelial cell damage and senescence, while inducing arteriogenesis and angiogenesis in CLI mice. C_LIO_LIIn arteries of patients with PAD and in CLI mouse models, the expression levels of B55, Caveolin 1, and Sirtuin 1 are diminished. However, treatment with Etrinabdione specifically in CLI mice prompts an increase in the levels of these proteins. C_LIO_LIEtrinabdione triggers neovascularization and angiogenesis specifically within hypoxic tissue in a critical ischemia model, with no impact on healthy tissue. C_LI

pharmacology and toxicology↗

bioRxiv2024

Fetal protection against bovine viral diarrhea virus types 1 and 2 after vaccination of the dam with the DIVENCE vaccine

The aim of this study was to demonstrate the efficacy of DIVENCE, a vaccine against BVDV types 1 and 2 (BVDV-1 and BVDV-2) transplacental infection, following a booster regimen in heifers. Calves of two-to-three months of age were given two intramuscular doses three weeks apart and a booster vaccine six months later. Efficacy was evaluated by means of a challenge with virulent BVDV-1 or BVDV-2 administered via the intranasal route at 85 days of gestation. Clinical signs, serology, viral shedding, WBC count and viremia were monitored after the challenge. Sixty-six days post-challenge, the fetuses were assessed for BVDV to detect transplacental infection. The results demonstrate a reduction in hyperthermia, leukopenia, viral shedding, and viremia in vaccinated animals post-challenge with BVDV-1 and BVDV-2. Most importantly, DIVENCE administered prior to breeding protected 94% of the fetuses against BVDV transplacental infection overall across both challenge trials (BVDV-1 and BVDV-2).

immunology↗

bioRxiv2023

Chemo-phosphoproteomic profiling with ATR inhibitors berzosertib and gartisertib uncovers new biomarkers and DNA damage response regulators

The ATR kinase protects cells against DNA damage and replication stress and represents a promising anti-cancer drug target. The ATR inhibitors (ATRi) berzosertib and gartisertib are in clinical trials for treatment of advanced solid tumours as monotherapy or in combination with genotoxic agents. However, the pharmacodynamic ATR biomarker phospho-CHK1 has shown limited sensitivity in for quantitative assessment of ATR activity in clinical trials. Therefore, better biomarkers are needed, and with this in mind we carried out quantitative phospho-proteomic screening for ATR biomarkers that are highly sensitive to berzosertib and gartisertib. Screening identified novel ATR-dependent targets in three broad classes: i) targets whose phosphorylation is highly sensitive to ATRi; ii) novel targets with known genome maintenance roles; iii) novel targets whose cellular roles are unclear, including SCAF1. We show that SCAF1 interacts with RNAPII in a phospho-dependent manner and suppresses homologous recombination in cells lacking the BRCA1 tumour suppressor. Taken together these data reveal potential new ATR biomarkers and new genome maintenance factors.

biochemistry↗

bioRxiv2023

Evolutionarily diverse origins of honey bee deformed wing viruses

Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses and, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemiology. As the principal driver of the spread of Deformed Wing Viruses (mainly DWV-A and DWV-B), varroa infestation has also driven global honey bee health declines. The more virulent DWV-B strain has been replacing the original DWV-A strain in many regions over the past two decades. Yet, how these viruses originated and spread remains poorly understood. Here we use a phylogeographic analysis based on whole genome data to reconstruct the origins and demography of DWV spread. We found that, rather than reemerging in western honey bees after varroa switched hosts, as suggested by previous work, DWV-A most likely originated in Asia and spread in the mid-20th century. It also showed a massive population size expansion following the varroa host switch. By contrast, DWV-B was most likely acquired more recently from a source outside Asia, and appears absent from eastern honey bees, the original varroa host. These results highlight the dynamic nature of viral adaptation, whereby a vectors host switch can give rise to competing and increasingly virulent disease pandemics. The evolutionary novelty and rapid global spread of these host-virus interactions, together with observed spillover into other species, illustrate how increasing globalisation poses urgent threats to biodiversity and food security.

evolutionary biology↗

bioRxiv2020

Epilepsy kinase CDKL5 is a DNA damage sensor which controls transcriptional activity at DNA breaks

Mutation of the CDKL5 kinase gene leads to the seizure-prone neurodevelopmental condition CDD (CDKL5 deficiency disorder) and is the most common genetic cause of childhood epilepsy. However, the phospho-targets and roles of CDKL5 are poorly understood, especially in the nucleus. We reveal CDKL5 as a sensor of DNA damage in actively transcribed regions of the nucleus, which phosphorylates transcriptional regulators such as Elongin A (ELOA) on a specific consensus motif. Recruitment of CDKL5 and ELOA to DNA damage sites, and subsequent ELOA phosphorylation, requires both active transcription and synthesis of poly-ADP ribose to which CDKL5 can bind. Critically, CDKL5 is essential for transcriptional control at DNA breaks. Therefore, CDKL5 is a DNA damage-sensing regulator of transcription, with implications for CDKL5-related human diseases. One sentence summaryCDKL5 is a DNA damage-sensing kinase that modulates transcriptional activity near DNA breaks.

cell biology↗

bioRxiv2020

Machine-learning model led design to experimentally test species thermal limits: the case of kissing bugs (Triatominae)

Species Distribution Modelling (SDM) determines habitat suitability of a species across geographic areas using macro-climatic variables; however, micro-habitats can buffer or exacerbate the influence of macro-climatic variables, requiring links between physiology and species persistence. Experimental approaches linking species physiology to micro-climate are complex, time consuming and expensive. E.g., what combination of exposure time and temperature is important for a species thermal tolerance is difficult to judge a priori. We tackled this problem using an active learning approach that utilized machine learning methods to guide thermal tolerance experimental design for three kissing-bug species (Hemiptera: Reduviidae: Triatominae), vectors of the parasite causing Chagas disease. As with other pathogen vectors, triatomines are well known to utilize micro-habitats and the associated shift in microclimate to enhance survival. Using a limited literature-collected dataset, our approach showed that temperature followed by exposure time were the strongest predictors of mortality; species played a minor role, and life stage was the least important. Further, we identified complex but biologically plausible nonlinear interactions between temperature and exposure time in shaping mortality, together setting the potential thermal limits of triatomines. The results from this data led to the design of new experiments with laboratory results that produced novel insights of the effects of temperature and exposure for the triatomines. These results, in turn, can be used to better model micro-climatic envelope for the species. Here we demonstrate the power of an active learning approach to explore experimental space to design laboratory studies testing species thermal limits. Our analytical pipeline can be easily adapted to other systems and we provide code to allow practitioners to perform similar analyses. Not only does our approach have the potential to save time and money: it can also increase our understanding of the links between species physiology and climate, a topic of increasing ecological importance. Author summarySpecies Distribution Modelling determines habitat suitability of a species across geographic areas using macro-climatic variables; however, micro-habitats can buffer or exacerbate the influence of macro-climatic variables, requiring links between physiology and species persistence. We tackled the problem of the combination of exposure time and temperature (a combination difficult to judge a priori) in determining species thermal tolerance, using an active learning approach that utilized machine learning methods to guide thermal tolerance experimental design for three kissing-bug species, vectors of the parasite causing Chagas disease. These bugs are found in micro-habitats with associated shifts in microclimate to enhance survival. Using a limited literature-collected dataset, we showed that temperature followed by exposure time were the strongest predictors of mortality, that species played a minor role, that life stage was the least important, and a complex nonlinear interaction between temperature and exposure time in shaping mortality of kissing bugs. These results led to the design of new laboratory experiments to assess the effects of temperature and exposure for the triatomines. These results can be used to better model micro-climatic envelope for species. Our active learning approach to explore experimental space to design laboratory studies can also be applied to other environmental conditions or species.

physiology↗

bioRxiv2017

SINHCAF/FAM60A links SIN3A function to the hypoxia response and its levels are predictive of cancer patient survival

The SIN3A-HDAC complex is a master transcriptional repressor, required for development but often deregulated in disease. Here, we report that the recently identified new component of this complex, SINHCAF/FAM60A, links the SIN3A-HDAC co-repressor complex function to the hypoxia response. SINHCAF Chromatin Immunoprecipitation-sequencing and gene expression analysis reveal a signature associated with the activation of the hypoxia response. We show that SINHCAF specifically repress HIF 2 mRNA and protein expression resulting in functional cellular changes in in-vitro angiogenesis, and proliferation. Analysis of patient datasets demonstrates that SINHCAF and HIF 2 mRNA levels are inversely correlated and predict contrasting outcomes for patient survival in both colon and lung cancer. This relationship is also observed in a mouse model of colon cancer, indicating an evolutionary conserved mechanism. Our analysis reveals an unexpected link between SINHCAF and cancer cell signalling via regulation of the hypoxia response that is predictive of poor patient outcome.

molecular biology↗