TRPC3 shapes the ER-mitochondria Ca2+ transfer characterizing tumour-promoting senescence
Valério Farfariello, Dmitri Gordienko, Lina Mesilmany, Yasmine Touil, Emmanuelle Germain, Ingrid Fliniaux, Emilie Desruelles, Dimitra Gkika, Morad Roudbaraki, George Shapovalov, Lucile Noyer, Mathilde Lebas, Laurent Allart, Nathalie Zienthal-Gelus, Oksana Iamshanova, Franck Bonardi, Martin Figeac, William Laine, Jérôme Kluza, Philippe Marchetti, Bruno Quesnel, Daniel METZGER, David Bernard, Jan B. Parys, Loïc Lemonnier, Natalia Prevarskaya
Abstract
Abstract Cellular senescence is implicated in a great number of diseases including cancer. Although alterations in mitochondrial metabolism were reported as senescence drivers, the underlying mechanisms remain elusive. We report the mechanism altering mitochondrial function and OXPHOS in stress-induced senescent fibroblasts. We demonstrate that TRPC3 protein, acting as a controller of mitochondrial Ca 2+ load via negative regulation of IP 3 receptor-mediated Ca 2+ release, is down regulated in senescence regardless of the type of senescence inducer. This remodelling promotes cytosolic/mitochondrial Ca 2+ oscillations and elevates mitochondrial Ca 2+ load, mitochondrial oxygen consumption rate and oxidative phosphorylation. Re-expression of TRPC3 in senescent cells diminishes mitochondrial Ca 2+ load and promotes escape from OIS-induced senescence. Cellular senescence evoked by TRPC3 downregulation in stromal cells displays a proinflammatory and tumour-promoting secretome that encourages cancer epithelial cell proliferation and tumour growth in vivo. Altogether, our results unravel the mechanism contributing to pro-tumour behaviour of senescent cells.