In hypothalamic neurons, declining NAD+ shortens primary cilia and blocks trafficking of the lysosomal repair protein CHMP4B, impairing calcium-dependent lysosomal stress responses and driving age-related metabolic dysfunction. Calorie restriction restored hypothalamic NAD+, ciliary length, and lysosomal integrity in aged mice, with metabolic improvement depending on intact cilia. The work positions a cilia-based signaling axis as a control point linking cellular energy currency to the brain's regulation of whole-body metabolism.
Key Points
- NAD+ depletion shortens hypothalamic primary cilia and suppresses lysosomal activity
- Ciliary dysfunction blocks CHMP4B recruitment, disrupting TRPML1 calcium signaling
- Calorie restriction restored cilia and reversed metabolic aging in mice
Longevity Analysis
Hypothalamic neurons act as a central interpreter of metabolic status, and this work shows that their ability to read and respond to signals depends on cellular NAD+ availability and the structural integrity of the cilium. When lysosomal repair machinery fails to reach damaged membranes, the cell's capacity to clear and recycle its own debris degrades — a breakdown in waste handling that propagates outward into systemic metabolic decline. Caloric restriction's benefit operating through this specific route reframes dietary restriction not as a generic stressor but as a targeted restoration of signaling fidelity in a small population of regulatory neurons.
Original published by Wiley Aging Cell, by Se Eun Park, Eun Roh, Jae Woo Park, Seong Jun Kim, So Yeon Jeong, Chae Beom Park, Hyo Sun Lim, Ji Soo Kim, Mun Gyeom Kim, Myeong Ju Kim, Young In Cho, Wontae Jeong, Gil Myoung Kang, Sang‐Yeob Kim, Se Hee Min, Min‐Seon Kim .