Moreover, this compromises vasoprotective sirtuin-mediated signalling pathways due to nicotinamide adenine dinucleotide (NAD+) depletion from pro-inflammatory PARP-1 [poly (ADP-ribose) polymerase 1] activation, further decreasing eNOS transcription, impairing the quiescent state of the endothelium.117 In sum, SARS-CoV-2 infection brings about acute and chronic endothelial activation,54 potentially mediating impairment of NVC in convalescent COVID-19 patients. This evidence concerns the gene PARP1 and COVID-19.