Biology subjects

Uhart, M.

Publications and source records attributed to Uhart, M..

6 recordsLinked to original sources

bioRxiv2026

Differential induction of 14-3-3 paralogs expression during early and late adipogenesis

Obesity is a major public health challenge of the 21st century, particularly in low- and middle-income populations. Adipogenesis plays a central role in the development of obesity and associated metabolic disorders, as it determines adipocyte number, size, and function. The 14-3-3 protein family comprises seven paralogs in mammals that regulate multiple cellular processes, yet their specific roles during adipogenesis remain poorly understood. In this study, we characterized the expression profiles of 14-3-3 paralogs during the early and late stages of adipogenic differentiation using quantitative PCR under standard adipogenic differentiation medium and modified drug-supplemented conditions. We found that the expression of specific paralogs is strongly influenced by the composition of the differentiation medium. The absence of insulin led to an early increase in Ywhaz, which could not be maintained during late adipogenesis and was associated with impaired adipogenic differentiation. In contrast, stimulation with incretins in combination with insulin induced late expression of Ywhag and Ywhab paralogs and promoted the formation of a greater number of smaller lipid droplets. These findings indicate that individual 14-3-3 paralogs exert distinct and context-dependent effects on adipogenesis, highlighting their potential roles as modulators of adipocyte differentiation and metabolic function.

biochemistry↗

bioRxiv2025

Novel Highly Pathogenic Avian Influenza (A)H5N1 Triple Reassortant in Argentina, 2025

Genomic sequencing of re-emerging highly pathogenic avian influenza A(H5N1) virus detected in Argentina in February 2025 revealed novel triple-reassortant viruses containing gene segments from Eurasian H5N1 and low pathogenic viruses from South and North American lineages. These findings underscore continued evolution and diversification of clade 2.3.4.4b H5N1 in the Americas.

genomics↗

bioRxiv2024

Shifting human-rodent interfaces under climate change: modeling the distribution of the reservoir for Junin virus and associated drivers

BackgroundThe drylands vesper mouse (Calomys musculinus) is the principal host for Junin mammarenavirus (JUNV), which causes Argentine Hemorrhagic Fever (AHF) in humans. In our study, we aimed to assess the probable range of C. musculinus and to identify hotspots for potential disease transmission to humans under current and future climate change scenarios. Methodology/Principal FindingsWe used tree-based machine learning (ML) classification algorithms to generate and project C. musculinus habitat suitability under two climate change scenarios for the years 2050 and 2070 using bioclimatic and landscape related predictors. Evaluation of the models showed high accuracy, with AUCROC ranging from 86.81-89.84%. The analysis of the importance and influence of different variables indicated that the rodent prefers warm temperatures, moderate annual precipitation, low precipitation variability, and low pasture coverage. While a severe climate change scenario (Representative Concentration Pathway 8.5) suggests a reduction in suitable areas for JUNV reservoir and a decrease in hotspots for potential disease transmission, an intermediate scenario (Representative Concentration Pathway 4.5) displays expansion in areas for C. musculinus distribution alongside increased potential hotspot zones. Conclusions/SignificanceWhile acknowledging the complexity of ecological systems and the limitations of the species distribution models, our findings offer a framework for developing preventive measures and conducting ecological studies in regions prone to C. musculinus expansion and hotspots for potential disease transmission driven by climate change. Preventive interventions will need to be adapted to target C. musculinus changing spatial dynamics. Author SummaryClimate change might modify where animals live, including those that carry diseases than can spread to humans. This study focused on how climate change might affect the drylands vesper mouse (Calomys musculinus). This rodent carries the Junin virus, which causes Argentine Hemorrhagic Fever, a dangerous disease if left untreated. We used species distribution models to predict how this rodents range might change by 2050 and 2070 under an intermediate and severe climate change scenario. We found that a temperature rise of 1.1{degrees}C to 2.6{degrees}C (intermediate change scenario) could allow the rodent to move into new areas, potentially increasing disease transmission to humans. These new areas might have warm temperatures, moderate rainfall, and low grass cover, as we found that C. musculinus prefers those climate and landscape conditions. Knowing the rodents potential distribution and preferred habitat enables preparedness and monitoring for early warning systems. By establishing monitor systems and online platforms featuring species distribution models and predictions, we can facilitate communication and resource sharing among researchers, policymakers, healthcare professionals and the public. These tools will help protect public health as climate change continues to bring new challenges.

ecology↗

bioRxiv2020

Sarcoptic mange; an emerging threat to Chilean wild mammals?

Sarcoptic mange has been anecdotally reported in Chilean wildlife during the last decade. Although this disease can have devastating outcomes for biodiversity, there is no comprehensive assessment of this potential threat in Chile. Because the current capacity to monitor sarcoptic mange and other wildlife diseases is limited in this country, we used abnormal alopecia to search for suspect cases across several sources of information to identify, to the extent available data allow, the location and temporal trends of wild mammals with this characteristic across Chile. We surveyed park rangers, examined rehabilitation center databases, and collated citizen and media reports. The information gathered suggests that observations of alopecic wild mammals, mainly foxes (Lycalopex sp.), their presence in the country, and the number of species fulfilling our case definition have increased over the last 15 years. Moreover, abnormally alopecic mammals are currently located broadly in Chile. We also confirmed the utility of abnormal alopecia to define a suspect sarcoptic mange case in the most commonly affected group, Lycalopex foxes. Our findings are highly concerning from a conservation perspective. We thus emphasize the need for an urgent surveillance and management plan for sarcoptic mange and other diseases that may be threatening Chilean biodiversity.

ecology↗

bioRxiv2019

14-3-3β paralog is inhibited by acetylation during differentiation to the osteogenic lineage.

14-3-3 protein family binds and regulate hundred of serine/threonine phosphorylated proteins. Considered as redundant, ubiquitous and constantly expressed this protein family was treated as an accessory for many signaling systems. Here we studied the reversible inhibition by acetylation of its essential N-{varepsilon}-lysine 49/51 residue during the osteogenic differentiation of human adipose-derived stem cells (ASC). We found that during the differentiation of ASC the levels of 14-3-3 acK49/51 increase showing that inhibition of 14-3-3 is necessary for this process. Among the 7 paralogs of this family, the inhibition by this posttranslational modification occurs mostly on the paralog {beta} located specifically in the nucleus where 14-3-3 was described to binds to H3 histone and many transcription factors. Short hairpin RNA silencing of 14-3-3{beta} gene but not 14-3-3{gamma} increases significantly the osteogenic potential of the cells. These results show that specifically 14-3-3{beta} is a negative regulator of osteogenesis and its inhibition by acetylation on lysine 51 is the cellular mechanism to regulate it.

cell biology↗

bioRxiv2019

Positively selected variants in functionally important regions of TLR7 in Alouatta guariba clamitans with yellow fever virus exposure in Northern Argentina

1In 2007-2009, a ma jor yellow fever virus (YFV) outbreak in Northern Argentina decimated the local howler monkey (Alouatta) population. We explored the relationship between Toll-like receptor (TLR) 7 and TLR8 gene variation and YFV susceptibility using samples from Alouatta individuals alive before the YFV outbreak, individuals that died during the outbreak, and individuals that survived the outbreak and are alive today. We measured genetic divergence between Alouatta YFV exposure groups and evaluated Alouatta-specific substitutions for functional consequences. We did not find different allele frequencies in the post-YFV exposure Alouatta group compared to the pre-exposure group. However, we identified three nonsynonymous variants in TLR7 in A. guariba clamitans. Two of these substitutions are under positive selection in functionally important regions of the gene. These unique coding differences in A. guariba clamitans may affect YFV resistance, but more work is necessary to fully explore this hypothesis.

evolutionary biology↗