CD38 Enzyme Emerges as a Key Target for Reversing Age-Related NAD+ Decline
CD38 activity rises with age, depleting NAD+ and accelerating tissue decline. New research positions CD38 inhibitors as promising anti-aging therapeutics.
Summary
NAD+ is critical for cellular energy and metabolism, but its levels fall sharply with age. A major culprit appears to be CD38, a multifunctional enzyme that consumes NAD+ and becomes increasingly active as we age. Research shows that CD38 upregulation correlates directly with age-related NAD+ depletion, while CD38 deficiency slows aging in animal models. This comprehensive review from Ocean University of China examines the physiological roles of CD38, its molecular mechanisms in aging and age-related disease, and the therapeutic potential of small-molecule CD38 inhibitors. The findings position CD38 as a compelling drug target for longevity interventions aimed at restoring youthful NAD+ levels.
Detailed Summary
NAD+ is one of the most studied molecules in longevity science, playing essential roles in DNA repair, mitochondrial function, and cellular energy metabolism. Its decline with age is well-established and has been linked to a wide range of age-related diseases. Understanding what drives this decline is critical for developing effective interventions.
This 2025 review, published in Biochemical Pharmacology, focuses on CD38 — a multifunctional NAD+-consuming enzyme — as a central driver of age-related NAD+ depletion. The authors systematically examine CD38's physiological roles, its upregulation during aging, and the downstream consequences for tissue homeostasis and disease progression.
Key evidence reviewed includes studies showing that CD38 expression increases significantly with age across multiple tissues, creating a metabolic drain on NAD+ that outpaces the body's ability to synthesize it. Crucially, animal models lacking CD38 demonstrate slower aging phenotypes and preserved NAD+ levels, offering strong causal evidence for CD38's role in the aging process.
The review also catalogs the molecular mechanisms by which elevated CD38 activity contributes to age-related diseases, including metabolic disorders, neurodegeneration, and immune dysfunction. Small-molecule inhibitors of CD38 are highlighted as a promising therapeutic class, with the authors surveying existing compounds and their potential for clinical translation in anti-aging contexts.
While the findings are compelling, this is a review paper based primarily on animal and preclinical data. Human clinical trials specifically targeting CD38 for aging remain limited. Nonetheless, CD38 inhibition represents a mechanistically distinct and complementary strategy to NAD+ precursor supplementation (e.g., NR, NMN), and may ultimately prove more efficient at restoring NAD+ homeostasis in aged tissues.
Key Findings
- CD38 expression increases with age, driving NAD+ depletion across multiple tissues.
- CD38-deficient animal models show slower aging and preserved NAD+ levels.
- CD38 inhibition is identified as a mechanistically distinct alternative to NAD+ precursor supplementation.
- Small-molecule CD38 inhibitors show therapeutic promise for age-related metabolic and neurodegenerative diseases.
- Restoring NAD+ via CD38 targeting may broadly ameliorate age-related tissue degeneration.
Methodology
This is a comprehensive narrative review synthesizing published preclinical and mechanistic research on CD38 and NAD+ biology in aging. The authors draw on animal model studies, molecular pathway analyses, and pharmacological data. No original experimental data were generated by the review authors.
Study Limitations
This is a review paper, not an original clinical trial, so causal conclusions in humans remain preliminary. Most supporting evidence comes from animal models, which may not fully translate to human aging biology. The clinical development of CD38-specific inhibitors for aging indications is still in early stages.
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