Crucial role of visfatin/pre-B cell colony-enhancing factor in matrix degradation and prostaglandin E2 synthesis in chondrocytes: possible influence on osteoarthritis

Gosset M, Berenbaum F, Salvat C, et al. · Arthritis and Rheumatism

COMPLICATING EVIDENCE: extracellular NAMPT (visfatin) — the same enzyme that makes NMN endogenously — drove prostaglandin E2 release and matrix-degrading activity in chondrocytes, showing the NAD+ pathway is not uniformly 'good' for cartilage.

Population

Cultured chondrocytes

Intervention

Visfatin/NAMPT (the NAD+ salvage-pathway enzyme, acting extracellularly)

Comparator

Untreated chondrocytes

Limitations

In-vitro; extracellular NAMPT signalling is distinct from intracellular NAD+ synthesis, but it cautions against a simple 'more NAD+ pathway = better joints' story.