Abstract
Decreased NAD+ levels have been shown to contribute to metabolic dysfunction during aging. NAD+ decline can be partially prevented by knockout of the enzyme CD38. However, it is not known how CD38 is regulated during aging, and how its ecto-enzymatic activity impacts NAD+ homeostasis. Here we show that an increase in CD38 in white adipose tissue (WAT) and the liver during aging is mediated by accumulation of CD38+ immune cells. Inflammation increases CD38 and decreases NAD+. In addition, senescent cells and their secreted signals promote accumulation of CD38+ cells in WAT, and ablation of senescent cells or their secretory phenotype decreases CD38, partially reversing NAD+ decline. Finally, blocking the ecto-enzymatic activity of CD38 can increase NAD+ through a nicotinamide mononucleotide (NMN)-dependent process. Our findings demonstrate that senescence-induced inflammation promotes accumulation of CD38 in immune cells that, through its ecto-enzymatic activity, decreases levels of NMN and NAD+.
Original language | English (US) |
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Pages (from-to) | 1284-1304 |
Number of pages | 21 |
Journal | Nature Metabolism |
Volume | 2 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2020 |
All Science Journal Classification (ASJC) codes
- Physiology (medical)
- Internal Medicine
- Endocrinology, Diabetes and Metabolism
- Cell Biology