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bioRxiv · 10.1101/375212

NAD consumption by PARP1 in response to DNA damage triggers metabolic shift critical for damaged cell survival

Murata, M.·Kong, X.·Moncada, E.·Chen, Y.·Wang, P. H.·Berns, M. W.·Yokomori, K.·Digman, M.
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Abstract

DNA damage signaling is critical for the maintenance of genome integrity and cell fate decision. Poly(ADP-ribose) polymerase 1 (PARP1) is a DNA damage sensor rapidly activated in a damage dose and complexity-dependent manner playing a critical role in the initial chromatin organization and DNA repair pathway choice at damage sites. However, the cell-wide consequence of its activation in damaged cells is not well delineated. Using the phasor approach to fluorescence lifetime imaging microscopy (FLIM) and fluorescence-based biosensors in combination with laser microirradiation, we found a rapid cell-wide increase of the bound/free NADH ratio in response to nuclear DNA damage, which is triggered by NAD+ depletion by PARP activation. This change is linked to the metabolic balance shift to oxidative phosphorylation (oxphos) over glycolysis. Inhibition of the respiratory chain resulted in rapid PARP-dependent ATP reduction and intracellular acidification, and eventually, PARP-dependent, AIF-independent, apoptosis indicating that oxphos becomes critical for damaged cell survival. The results reveal the novel pro-survival effect of PARP activation through a change in cellular metabolism, and demonstrate how unique applications of advanced fluorescence imaging technologies in combination with laser microirradiation can be a powerful tool to interrogate damage-induced metabolic changes at high spatiotemporal resolution in a live cell.

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Murata, M., Kong, X., Moncada, E., Chen, Y., Wang, P. H., Berns, M. W., Yokomori, K., Digman, M.. 2018-07-24. NAD consumption by PARP1 in response to DNA damage triggers metabolic shift critical for damaged cell survival. https://doi.org/10.1101/375212

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