Superstable lipid vacuoles endow cartilage with its shape and biomechanics.
Journal
Science (New York, N.Y.)
Journal Volume
387
Journal Issue
6730
Start Page
eads9960
ISSN
1095-9203
Date Issued
2025-01-10
Author(s)
Ramos, Raul
Pham, Kim T
Prince, Richard C
Leiser-Miller, Leith B
Prasad, Maneeshi S
Wang, Xiaojie
Nordberg, Rachel C
Bielajew, Benjamin J
Hu, Jerry C
Yamaga, Kosuke
Oh, Ji Won
Peng, Tao
Datta, Rupsa
Astrowskaja, Aksana
Almet, Axel A
Burns, John T
Liu, Yuchen
Guerrero-Juarez, Christian Fernando
Tran, Bryant Q
Chu, Yi-Lin
Nguyen, Anh M
Hsi, Tsai-Ching
Lim, Norman T-L
Schoeniger, Sandra
Liu, Ruiqi
Pai, Yun-Ling
Vadivel, Chella K
Ingleby, Sandy
McKechnie, Andrew E
van Breukelen, Frank
Hoehn, Kyle L
Rasweiler, John J
Kohara, Michinori
Loughry, William J
Weldy, Scott H
Cosper, Raymond
Yang, Chao-Chun
Cooper, Kimberly L
Santana, Sharlene E
Bradley, Jeffrey E
Kiebish, Michael A
Digman, Michelle
James, David E
Merrill, Amy E
Nie, Qing
Schilling, Thomas F
Astrowski, Aliaksandr A
Potma, Eric O
García-Castro, Martín I
Athanasiou, Kyriacos A
Behringer, Richard R
Plikus, Maksim V
Abstract
Conventionally, the size, shape, and biomechanics of cartilages are determined by their voluminous extracellular matrix. By contrast, we found that multiple murine cartilages consist of lipid-filled cells called lipochondrocytes. Despite resembling adipocytes, lipochondrocytes were molecularly distinct and produced lipids exclusively through de novo lipogenesis. Consequently, lipochondrocytes grew uniform lipid droplets that resisted systemic lipid surges and did not enlarge upon obesity. Lipochondrocytes also lacked lipid mobilization factors, which enabled exceptional vacuole stability and protected cartilage from shrinking upon starvation. Lipid droplets modulated lipocartilage biomechanics by decreasing the tissue's stiffness, strength, and resilience. Lipochondrocytes were found in multiple mammals, including humans, but not in nonmammalian tetrapods. Thus, analogous to bubble wrap, superstable lipid vacuoles confer skeletal tissue with cartilage-like properties without "packing foam-like" extracellular matrix.
SDGs
Type
journal article