Biology subjects

Iebba, V.

Publications and source records attributed to Iebba, V..

2 recordsLinked to original sources

bioRxiv2024

Population dynamics after pancreatitis dictates long-lasting epigenetic reprogramming and mediates tumor predisposition

Local inflammation in the pancreas is transient but imprints a durable epigenetic memory on epithelial cells, making them more amenable to oncogenic transformation. However, it is unclear whether epithelial cell heterogeneity is impacted by acute pancreatitis (AP) or whether population dynamics during regeneration contributes to the establishment of inflammation memory. To tackle those questions, we deployed experimental pancreatitis in mice and performed paired sequencing of transcriptomic and chromatin accessibility profiles at single nucleus resolution. We documented cell type abundance but also applied integrative analyses to infer phenotypically-distinct clusters of mesenchymal and exocrine cells. We found that AP perturbs a subset of "idling" acinar cells, which separate from more canonical "secretory" acini based on a more diversified proteome, which include elevated expression of signal transduction receptors. We linked acinar cell heterogeneity to epigenetic differences that also endow idling cells with superior plasticity. These constitute about 40% of acinar cells but can proliferate and skew their phenotype in response to AP. This leads to a remarkable recovery of pancreas histology and function, but also to the dissemination of idling-like features across the exocrine parenchyma. Mechanistically, idling acinar cells are characterized by enhanced transcriptional activity and protein synthesis. After recovery from pancreatitis, acini show elevation of both and establishment of chronic Unfolded Protein Response (UPR). We finally demonstrated that AP-primed pancreata show signs of elevated UPR and that ER stress promotes acinar cell metaplasia. Our data interrogate phenotypical dynamics during tissue regeneration to identify cell states amenable to epigenetic imprinting. They also suggest that UPR-alleviating strategies might curtail the risk of developing pancreatic cancer for individuals who experiences AP.

cell biology↗

bioRxiv2020

Profiling of oral microbiota and cytokines in COVID-19 patients

SARS-CoV-2 presence has been recently demonstrated in the sputum or saliva, suggesting how the shedding of viral RNA outlasts the end of symptoms. Recent data from transcriptome analysis show that oral cavity mucosa harbors high levels of ACE2 and TMPRSS2, highlighting its role as a double-edged sword for SARS-CoV-2 body entrance or interpersonal transmission. In the present study, for the first time, we demonstrate the oral microbiota structure and inflammatory profile of COVID-19 patients. Hospitalized COVID-19 patients and matched healthy controls underwent naso/oral-pharyngeal and oral swabs. Microbiota structure was analyzed by 16S rRNA V2 automated targeted sequencing, while oral and sera concentrations of 27 cytokines were assessed using magnetic bead-based multiplex immunoassays. A significant diminution in species richness was observed in COVID-19 patients, along with a marked difference in beta-diversity. Species such as Prevotella salivae and Veillonella infantium were distinctive for COVID-19 patients, while Neisseria perflava and Granulicatella elegans were predominant in controls. Interestingly, these two groups of oral species oppositely clustered within the bacterial network, defining two distinct Species Interacting Group (SIGs). Pro-inflammatory cytokines were distinctive for COVID-19 in both oral and serum samples, and we found a specific bacterial consortium able to counteract them, following a novel index called C4 firstly proposed here. We even introduced a new parameter, named CytoCOV, able to predict COVID-19 susceptibility for an unknown subject at 71% of power with an AUC equal to 0.995. This pilot study evidenced a distinctive oral microbiota composition in COVID-19 subjects, with a definite structural network in relation to secreted cytokines. Our results would pave the way for a theranostic approach in fighting COVID-19, trying to enlighten the intimate relationship among microbiota and SARS-CoV-2 infection.

microbiology↗