An NAD(+)-responsive adipose signal coordinates inter-organ defense against muscle atrophy.

Elevated NAD+ in adipose tissue triggers Serpina3n release, which protects muscle mass across aging, disuse, and cancer cachexia models.

• Why it matters: Understanding how systemic metabolic signals safeguard muscle integrity could lead to new therapies for muscle degeneration-related conditions like frailty and disability.
• What they did: The study used models of aging, disuse, and cancer cachexia to show that NAD+ supplementation increases Serpina3n via STAT1-dependent transcription in adipose tissue, resulting in systemic muscle protection.
• The result: Serpina3n preserves pyruvate carboxylase levels in muscle, promoting metabolism and protein synthesis, thereby revealing a systemic NAD+-responsive adipose-to-muscle signaling pathway that may inform anti-atrophy strategies.