Biology subjects

Ciesla, J.

Publications and source records attributed to Ciesla, J..

3 recordsLinked to original sources

bioRxiv2024

Fmp40 ampylase regulates cell survival upon oxidative stress by controlling Prx1 and Trx3 oxidation

Reactive oxygen species (ROS), play important roles in cellular signaling, nonetheless are toxic at higher concentrations. Cells have many interconnected, overlapped or backup systems to neutralize ROS, but their regulatory mechanisms remain poorly understood. Here, we reveal an essential role for mitochondrial AMPylase Fmp40 from budding yeast in regulating the redox states of mitochondrial 1-Cys peroxiredoxin, Prx1, which is the only protein shown to neutralize H2O2 with the oxidation of the mitochondrial glutathione and Trx3, thioredoxin, directly involved in the reduction of Prx1. Deletion of FMP40 impacts a cellular response to H2O2 treatment that leads to programmed cell death (PCD) induction and an adaptive response involving up or down regulation of genes encoding, among others the catalase Cta1, PCD inducing factor Aif1, and mitochondrial redoxins Trx3 and Grx2. This ultimately perturbs the reduced glutathione and NADPH cellular pools. We further demonstrated that Fmp40 AMPylates Prx1, Trx3, and Grx2 in vitro and interacts with Trx3 in vivo. AMPylation of the threonine residue 66 in Trx3 is essential for this proteins proper endogenous level of and its precursor forms maturation under oxidative stress conditions. Additionally, we showed the Grx2 involvement in the reduction of Trx3 in vivo. Taken together, Fmp40, through control of the reduction of mitochondrial redoxins, regulates the hydrogen peroxide, GSH and NADPH signaling influencing the programmed cell death execution. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=107 SRC="FIGDIR/small/590396v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@2bae9borg.highwire.dtl.DTLVardef@1d46514org.highwire.dtl.DTLVardef@1380c2aorg.highwire.dtl.DTLVardef@a6bad9_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2022

Distinct effects of intracellular vs. extracellular acidic pH on the cardiac metabolome during ischemia and reperfusion.

Tissue ischemia results in intracellular pH (pHIN) acidification, and while accumulation of metabolites such as lactate is a known driver of acidic pHIN, less is known about how acidic pHIN regulates metabolism. Furthermore, acidic extracellular (pHEX) during early reperfusion confers cardioprotection, but how this impacts metabolism is unclear. Herein we employed LCMS based targeted metabolomics to analyze perfused mouse hearts exposed to: (i) control perfusion, (ii) hypoxia, (iii) ischemia, (iv) enforced acidic pHIN, (v) control reperfusion, and (vi) acidic pHEX (6.8) reperfusion. Surprisingly little overlap was seen between metabolic changes induced by hypoxia, ischemia, and acidic pHIN. Acidic pHIN elevated metabolites in the top half of glycolysis, and enhanced glutathione redox state. Acidic pHEX reperfusion induced substantial metabolic changes in addition to those seen in control reperfusion. This included elevated metabolites in the top half of glycolysis, prevention of purine nucleotide loss, and an enhancement in glutathione redox state. These data led to parallel hypotheses regarding potential roles for methylglyoxal inhibiting the mitochondrial permeability transition pore, and for acidic inhibition of ecto-5-nucleotidase, as potential mediators of cardioprotection by acidic pHEX reperfusion. However, neither hypothesis was supported by subsequent experiments. In contrast, analysis of cardiac effluents revealed complex effects of pHEX on metabolite transport, suggesting that mildly acidic pHEX may protect in part by enhancing succinate release during reperfusion. Overall, each intervention had distinct and overlapping metabolic effects, suggesting acidic pH is an independent metabolic regulator regardless which side of the cell membrane it is imposed. HIGHLIGHTSO_LIHypoxia, ischemia and acidic pHIN each induce unique cardiac metabolic profiles. C_LIO_LIAcidic pHEX at reperfusion prevents purine loss and enhances succinate release. C_LI

biochemistry↗

bioRxiv2022

TNFα-induced metabolic reprogramming drives an intrinsic anti-viral state

Cytokines induce an anti-viral state, yet many of the functional determinants responsible for limiting viral infection are poorly understood. Here, we find that TNF induces significant metabolic remodeling that is critical for its anti-viral activity. Our data demonstrate that TNF activates glycolysis through the induction of muscle-specific hexokinase (HK2). Further, we show that glycolysis is broadly important for TNF-mediated anti-viral defense, as its inhibition attenuates TNFs ability to limit the replication of evolutionarily divergent viruses. Stable-isotope tracing revealed that TNF-mediated glycolytic activation promotes the biosynthesis of UDP-sugars (essential precursors of protein glycosylation) and that inhibition of glycolysis prevents the accumulation of several glycosylated anti-viral proteins. Consistent with the importance of glucose-driven glycosylation, glycosyl-transferase inhibition also attenuated TNFs ability to promote the anti-viral cell state. Collectively, our data indicate that cytokine-mediated metabolic remodeling is an essential component of the anti-viral response.

microbiology↗