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Perales, J. C.

Publications and source records attributed to Perales, J. C..

2 recordsLinked to original sources

Phospho-enol pyruvate carboxykinase inhibition limits inflammatory T cell activation

Following antigenic stimulation, T cells switch from a catabolic metabolic state maintained by low levels of nutrient uptake to an anabolic metabolism that sustains the biosynthetic and energetic demands of clonal expansion, differentiation and effector function. Much progress has been made in understanding the transcriptional and enzymatic regulation of activated T cell metabolism. However less is understood of the role for regulators of anaplerosis and cataplerosis such as phospho-enol pyruvate carboxykinases (PEPCK) in T cells. In the current work, we show that mitochondrial isoform PEPCK-M is upregulated following T cell activation whilst cytosolic PEPCK-C is not expressed. PEPCK inhibitors limited CD8+ T cell cytotoxic capacity and both CD4+ and CD8+ T cell inflammatory cytokine production. Suppression of T cell effector functions by PEPCK inhibitors was associated with decreased maximal mitochondrial respiration. These data suggest that PEPCK-M acts as a metabolic rheostat to enable optimal T cell activation.

immunology↗

A rise in double-strand breaks sensitizes tumours to oxidative metabolism inhibitors

ABSTRACTDouble strand brakes (DSB) accumulate in cellular DNA as a result of deficiencies in homologous recombination repair systems, such as mutations in BRCA genes, or upon antitumoral treatments. In the present study we show that the accumulation of DSB, regardless of its origins, leads to a shift towards oxidative metabolism. We have identified that DSB-induced reactive oxygen species (ROS) promote the activation of NRF2 which downregulates the glycolytic transcription factor HIF-1. HIF-1 inhibition is a key step in this metabolic shift, because leads to the reduction of PDHK1 levels and the consequential activation of pyruvate dehydrogenase, a mitochondrial gatekeeper of cellular metabolism, promoting this metabolic shift. Remarkably, after the induction of DSBs, the tumour is more sensitive to the inhibition of oxidative metabolism since both treatments synergize in vivo, resulting in reduced tumour growth. Therefore, we demonstrate a significant feedback between DSBs induction and cancer cell metabolism that ultimately limits the cells potential for metabolic plasticity, hence sensitizing it to the action of counteracting drugs.

cancer biology↗