Our livers are constantly fighting off damage. To win this war and keep our body metabolism running properly, liver cells lost due to acute injury or over the course of chronic disease are replaced by replicating mature cells. The ability to activate the acute regenerative response can be the determining factor between survival and death after a toxic or traumatic injury, transplant, or surgical resection. Despite decades of study, there remains no clinically proven therapy to support regeneration in patients at risk for liver failure or following an acute injury or surgical intervention.
Mukherjee and colleagues from the University of Pennsylvania published an article in JCI Insight showing that liver cell loss of longevity-associated enzymes called sirtuins drastically impairs regeneration after partial removal of the liver. Despite the dependence of these enzymes on the vital bioenergetic molecule nicotinamide adenine dinucleotide (NAD+) and critical roles in regeneration, SIRT1 and SIRT3 are not required for NAD+ precursors to enhance liver regeneration. Along these lines, the NAD+ precursor nicotinamide riboside (NR) rapidly increases liver cell function.