Biology subjects

Inesta-Vaquera, F.

Publications and source records attributed to Inesta-Vaquera, F..

4 recordsLinked to original sources

bioRxiv2023

Novel in vivo TDP-43 stress reporter models to accelerate drug development in ALS.

The development of therapies to combat neurodegenerative diseases is widely recognised as a research priority, with conditions like Alzheimers, Amyotrophic lateral sclerosis (ALS) and Parkinsons set to place an ever-heavier burden on healthcare systems in the near future. Despite recent advances in understanding their molecular basis, there is a lack of suitable early biomarkers to test selected compounds and accelerate their translation to clinical trials. We have investigated the utility of in vivo reporters of cytoprotective pathways (e.g. NRF2, p53) as surrogate early biomarkers of the ALS degenerative disease progression. We hypothesized that cellular stress observed in a model of ALS may precede overt cellular damage and could activate our cytoprotective pathway reporters. To test this hypothesis, we generated novel ALS-reporter mice by crossing the hTDP-43tg model into our oxidative stress/inflammation (Hmox1; NRF2 pathway) and DNA damage (p21; p53 pathway) stress reporter models. Histological analysis of reporter expression in a homozygous hTDP-43tg background demonstrated a time-dependent and tissue-specific activation of the reporters in tissues directly associated with ALS. The activation occurs in Purkinje neurons and other parvalbumin-positive (PV+) cells within the cerebellum of mice, before moderate clinical signs are observed. In addition, reporter expression in hTDP-43tg hom peripheral tissues was not observed at the tested mouse ages (15 and 17 days postnatally). Further work is warranted to determine the specific mechanisms by which TDP-43 accumulation leads to reporter activation and whether therapeutic intervention modulates reporters expression. Our current studies suggest that these reporters may represent a powerful approach to accelerate preclinical studies targeting TDP-43 pathologies. We anticipate the reporter strategy could be of great value in developing treatments for a range of degenerative disorders.

neuroscience↗

bioRxiv2022

Defining the in vivo mechanism of air pollutant toxicity using murine stress response biomarkers.

BackgroundAir pollution can cause a wide range of serious human diseases. For the informed instigation of interventions which prevent these outcomes there is an urgent need to develop robust in vivo biomarkers which provide insights into mechanisms of toxicity and relate pollutants to specific adverse outcomes. ObjectiveTo exemplify the application of in vivo stress response reporters in establishing mechanisms of air pollution toxicity and the application of this knowledge in epidemiological studies and potentially in disease prevention. MethodsMurine stress-reporter models (oxidative stress/inflammation, DNA damage and Ah receptor -AhR-activity) and primary mouse and primary human nasal cells were exposed to chemicals present in diesel exhaust emissions, particulate matter (PM) standards (PM2.5-SRM2975, PM10-SRM1648b) or fresh roadside PM10. Stress reporter activity was analysed by luminescence assays and histochemical approaches in a panel of murine tissues. Biochemical, genetic and pharmacological approaches were used to establish the mechanism of the stress responses observed. Pneumococcal adhesion was assessed in exposed primary human nasal epithelial cells (HPNEpC). ResultsNitro-PAHs induced Hmox1 and CYP1a1 reporters in a time- and dose-dependent, cell- and tissue-specific manner. NRF2 pathway mediated this Hmox1-reporter induction. SRM1658b, but not SRM2975, was a potent inducer of NRF2-dependent Hmox1 reporter activity in lung macrophages. Combined use of HPNEpC and in vivo reporters demonstrated that London roadside PM10 particles induced pneumococcal infection in HPNEpC mediated by oxidative stress responses. DiscussionThe combined use of in vivo reporter models with HPNEpC provides a robust approach to define the relationship between air pollutant exposure and health risks. These models can be used to hazard ranking environmental pollutants by considering the complexity of mechanisms of toxicity. These data will facilitate the relationship between toxic potential and the level of pollutant exposure in populations to be established and potentially extremely valuable tools for intervention studies.

pharmacology and toxicology↗

bioRxiv2020

Application of the in vivo oxidative stress reporter Hmox1 as mechanistic biomarker of arsenic toxicity.

Inorganic arsenic (iAs) is a naturally occurring metalloid present in drinking water and polluted air exposing millions of people globally. Epidemiological studies have linked iAs exposure to the development of numerous diseases including cognitive impairment, cardiovascular failure and cancer. Despite intense research, an effective therapy for chronic arsenicosis has yet to be developed. Laboratory studies have been of great benefit in establishing the pathways involved in iAs toxicity and providing insights into its mechanism of action. However, the in vivo analysis of arsenic toxicity mechanisms has been difficult by the lack of reliable in vivo biomarkers of the effects of iAs. To resolve this issue we have applied the use of our recently developed stress reporter models to study iAs toxicity. The reporter mice Hmox1 (oxidative stress/inflammation; HOTT) and p21 (DNA damage) were exposed to iAs at acute and chronic, environmentally relevant, doses. We observed induction of the oxidative stress reporters in several cell types and tissues, which was largely dependent on the activation of transcription factor NRF2. We propose that our HOTT reporter model can be used as a surrogate biomarker of iAs-induced oxidative stress, and it constitutes a first-inclass platform to develop treatments in arsenicosis. Indeed, in a proof of concept experiment, the HOTT reporter mice were able to predict the therapeutic utility of the antioxidant N-acetyl cysteine in the prevention of iAs associated toxicity.Competing Interest StatementThe authors have declared no competing interest.View Full Text

pharmacology and toxicology↗

bioRxiv2017

DHX15 regulates CMTR1-dependent gene expression and cell proliferation

CMTR1 contributes to mRNA cap formation by methylating the O-2 position of the 1st transcribed nucleotide ribose. mRNA cap O-2 methylation has roles in mRNA translation and self-RNA tolerance in innate immunity, however its role in cell physiology is unclear. We report that CMTR1 is recruited to Serine-5 phosphorylated RNA Pol II CTD, facilitating cotranscriptional methylation. We isolated CMTR1 in a complex with DHX15, an RNA helicase functioning in splicing and ribosome biogenesis, and characterised it as a regulator of CMTR1. When bound to DHX15, CMTR1 activity is repressed and prevented from binding to RNA pol II, thus constraining 1st nucleotide methylation to a co-transcriptional event. Conversely CMTR1 activates DHX15 helicase activity and influences its nuclear localisation, which is likely to impact on several nuclear functions. The impact of the CMTR1-DHX15 interaction is complex and will depend on the relative expression of these enzymes and their interactors, and the cellular dependency on different RNA processing pathways. In HCC1806 cells, the DHX15-CMTR1 interaction controls ribosome loading of a subset of mRNAs and impacts on cell proliferation.

cell biology↗