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Gosset, P.

Publications and source records attributed to Gosset, P..

5 recordsLinked to original sources

PU.1 Shapes Host Epigenetic Responses to Mycobacterium tuberculosis and Represents a Target for Host Directed Therapy

Mycobacterium tuberculosis (Mtb) infection induces widespread epigenetic changes in monocytes and macrophages. To characterize the critical factor responsible for Mtb-induced epigenetic responses, we performed an integrative analyses of chromatin modification (H3K27ac), transcription factor binding, and gene expression in human monocytes and macrophages. Our data identified PU.1 (SPI1) as a key transcriptional regulator to be upregulated and bound to gene promoters in response to Mtb. PU.1 enrichment was associated with enhanced proinflammatory and anti-apoptotic gene programs. PU.1 expression was also elevated in the lung tissues from Mtb-infected macaques and tuberculosis patients. PU.1 knockdown enhanced human macrophage apoptosis, dampened inflammation and reduced bacterial survival, suggesting its functional role in supporting Mtb infection. Pharmacological inhibition of PU.1 replicated the effects of knockdown, restricting Mtb growth without cytotoxicity. These findings identify PU.1 as a central node in the host epigenetic response to Mtb and a candidate for host-directed therapeutic targeting in tuberculosis.

immunology↗

Integrative metagenomics and metabolomics reveal age-associated gut microbiota and metabolite alterations in experimental COVID-19

Aging is a key contributor of morbidity and mortality during acute viral pneumonia. The potential role of age-associated dysbiosis on disease outcomes is still elusive. In the current study, we used high-resolution shotgun metagenomics and targeted metabolomics to characterize SARS-CoV-2-associated changes in the gut microbiota from young (2-month-old) and aged (22-month-old) hamsters, a valuable model of COVID-19. We show that age-related dysfunctions in the gut microbiota are linked to disease severity and long-term sequelae in older hamsters. Our data also reveal age-specific changes in the composition and metabolic activity of the gut microbiota during both the acute phase (day 7 post-infection, D7) and the recovery phase (D22) of infection. Aged hamsters exhibited the most notable shifts in gut microbiota composition and plasma metabolic profiles. Through an integrative analysis of metagenomics, metabolomics, and clinical data, we identified significant associations between bacterial taxa, metabolites and disease markers in the aged group. On D7 (high viral load and lung epithelial damage) and D22 (body weight loss and fibrosis), numerous amino acids, amino acid-related molecules, and indole derivatives were found to correlate with disease markers. In particular, a persistent decrease in phenylalanine, tryptophan, glutamic acid, and indoleacetic acid in aged animals positively correlated with poor recovery of body weight and/or lung fibrosis by D22. In younger hamsters, several bacterial taxa (Eubacterium, Oscillospiraceae, Lawsonibacter) and plasma metabolites (carnosine and cis-aconitic acid) were associated with mild disease outcomes. These findings support the need for age-specific microbiome-targeting strategies to more effectively manage acute viral pneumonia and long-term disease outcomes.

immunology↗

Malignant assignment of neuronal Na+ leak channel, NALCN: governor of Ca2+ oscillations-encoded invadopodogenesis

Cytosolic Ca2+ oscillations provide signaling input to several effector systems of the cell. These include neuronal development, migration and networking. Although similar signaling events are hijacked by highly aggressive cancer cells, the complexity of the neuron-like remodeling in metastasis remains to be explored. Here, using a variety of in vitro and in vivo techniques we show that strongly metastatic prostate cancer cells acquire specific Na+/Ca2+ signature required for persistent invasion. We identify the neuronal Na+ leak channel, NALCN, at the hot spots of the Ca2+ wave initiation and invadopodia formation. Mechanistically, NALCN associates functionally with plasmalemmal and mitochondrial Na+/Ca2+ exchangers, reactive oxygen species and store-operated channels to generate intracellular Ca2+ oscillations. In turn, this stimulates the activity of protooncogene Src kinase co-localized with NALCN, actin remodeling and secretion of proteolytic enzymes, thus increasing an invasive potential of the cancer cells and metastatic lesions in vivo (accessed in pre-clinical models). Overall, our findings provide new insight into the signaling pathway specific for metastatic cells where NALCN plays the role of the persistent invasion "launcher and controller".

cell biology↗

Nicotinic receptors atlas in the adult human lung

Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels responsible for the rapid neural and neuromuscular signal transmission. Although it is well documented that 16 subunits are encoded by the human genome, their presence in airway epithelial cells (AEC) remains poorly understood, and contribution to pathology is mainly discussed in the context of cancer. We analysed nAChR subunit expression in the human lung of smokers and non-smokers using transcriptomic data for whole lung tissues, isolated large AEC, and isolated small AEC. We identified differential expressions of nAChRs in terms of detection and repartition in the three modalities. Smoking-associated alterations were also unveiled. Then, we identified a nAChR transcriptomic print at a single cell level. Finally, we reported the localizations of detectable nAChRs in bronchi and large bronchioles. Thus, we compiled the first complete atlas of pulmonary nAChRs to open new avenues to further unravel the involvement of these receptors in lung homeostasis and respiratory diseases.

cell biology↗

Efficacy of chronic ultrasound neurostimulation on behaviors and distributed brain metabolism in depressive-like mice

Major depression is one of the main factors contributing to the Global Burden of Disease. Current treatment strategies (e.g., antidepressants and neurostimulation techniques) of major depression show some limitations including inaccuracy and invasiveness. Ultrasound neurostimulation (USNS) has been recently introduced as a physical non-invasive method for brain tissue stimulation and has gained increasing interest. In this study, we sought to evaluate the efficacy of transcranial USNS in an unpredictable chronic mild stress (UCMS) mouse model. The results show that transcranial USNS of the infralimbic cortex reduced anxiety-related behaviors as well as some, but not all, depression-related parameters. [18F]-FDG microPET imaging and brain metabolomic analyses showed that USNS triggered the activation of targeted brain region in addition to brain areas at a distance from the targeted zone, alleviating anxiety and depression-related behaviors induced by the UCMS regimen. Transcranial ultrasound neurostimulation show therapeutic potential in some aspects of major depression.

neuroscience↗