Biology subjects

Salopiata, F.

Publications and source records attributed to Salopiata, F..

3 recordsLinked to original sources

bioRxiv2025

A quantitative approach to discover nonlinear signaling linking combinatorial environments with cellular responses

Cells constantly integrate diverse inputs from the extracellular environment, yet our understanding of how cells effectively process information from multiple cues at the same time remains limited. We utilized an integrated imaging platform and RNAseq analysis to investigate the combined effects of growth factors on cellular signaling and gene expression. Paired stimuli by receptor ligands revealed diverse signaling signatures-- ranging from antagonism to synergy--driving global signaling programs and gene expression. Notably, correlation networks based on signaling signatures identified vulnerabilities in cancer cells when compared to synergistic drug combinations. Profiling kinase and phosphatase activities uncovered a crucial interplay, where cellular sensitivity and phospho-turnover dynamics are modulated by input history through coordinated basal kinase and phosphatase activities. Our novel methodology sheds light on cellular processing of multiple cues, elucidating intricate mechanisms underlying cellular adaptation to extracellular environmental variations. Based on previous preprint: doi: https://doi.org/10.1101/346957

cell biology↗

bioRxiv2020

Identification of Interleukin1β as an Amplifier of Interferon alpha-induced Antiviral Responses

The induction of an interferon-mediated response is the first line of defense against pathogens such as viruses. Yet, the dynamics and extent of interferon alpha (IFN)-induced antiviral genes vary remarkably and comprise three expression clusters: early, intermediate and late. By mathematical modeling based on time-resolved quantitative data, we identified mRNA stability as well as a negative regulatory loop as key mechanisms endogenously controlling the expression dynamics of IFN-induced antiviral genes in hepatocytes. Guided by the mathematical model, we uncovered that this regulatory loop is mediated by the transcription factor IRF2 and showed that knock-down of IRF2 results in enhanced expression of early, intermediate and late IFN-induced antiviral genes. Co-stimulation experiments with different pro-inflammatory cytokines revealed that this amplified expression dynamics of the early, intermediate and late IFN-induced antiviral genes can be mimicked by co-application of IFN and interleukin1 beta (IL1{beta}). Consistently, we found that IL1{beta} enhances IFN-mediated repression of viral replication. Conversely, we observed that in IL1{beta} receptor knock-out mice replication of viruses sensitive to IFN is increased. Thus, IL1{beta} is capable to potentiate IFN-induced antiviral responses and could be exploited to improve antiviral therapies. Author SummaryInnate immune responses contribute to the control of viral infections and the induction of interferon alpha (IFN)-mediated antiviral responses is an important component. However, IFN induces a multitude of antiviral response genes and the expression dynamics of these genes can be classified as early, intermediate and late. Here we show, based on a mathematical modeling approach, that mRNA stability as well as the negative regulator IRF2 control the expression dynamics of IFN-induced antiviral genes. Knock-down of IRF2 resulted in the amplified IFN-mediated induction of the antiviral genes and this amplified expression of antiviral genes could be mimicked by co-stimulation with IFN and IL1{beta}. We observed that co-stimulation with IFN and IL1{beta} enhanced the repression of virus replication and that knock-out of the IL1 receptor in mice resulted in increased replication of a virus sensitive to IFN. In sum, our studies identified IL1{beta} as an important amplifier of IFN-induced antiviral responses.

systems biology↗

bioRxiv2018

A combinatorial extracellular code tunes the intracellular signaling network activity to distinct cellular responses

Cells constantly survey a complex set of inputs that is processed by the intracellular signaling network, but little is known of how cells integrate input information from more than one cue. We employed a FRET biosensor-based imaging platform to study the effect of combinatorial growth factor levels on the signaling network in human cells. We found that pairwise stimuli caused distinct concentration- and ratio-dependent signaling states through signaling signatures such as antagonism, additivity and synergy. The unique signaling states correlated with differential gene expression and non-additive transcription patterns. We further elucidated how a signal-rich environment can fine-tune the signaling network and adjust physiological outcomes, by kinase and phosphatase activity profiling. We describe how complex extracellular conditions affect phospho-turnover and the basal phosphorylation status. Thus, we provide mechanistic insights into cellular processing of multiple cues and explain part of the complexity of cellular adaptation to changes in the extracellular environment.

cell biology↗