All:
Before someone makes an excited post, "Repletion of Nicotinamide adenine dinucleotide restores adult stem cell function and extends lifespan in mice" is an editorial, not a new result: it mostly covers the Zhang et al paper. I note that the publisher is on Beall's List of Predatory Journals and Publishers.
The Zhang et al paper is a good piece of work, but it's not clear that it showed extended lifespan; and, there's the unfortunately near-universal caveat that it was done in C57BL/6J mice, who carry the NNT mutation (see also here and here for followup).