Ferroptosis Susceptibility: a Metabolic Amplifier of Bone Remodeling
- VernacularTitle:铁死亡易感性：骨重塑的代谢“放大器”
- Author:
Kuo LIU
1
;
Ran ZHANG
1
;
Yu-Shuo LIU
1
;
Rong-Yan ZHOU
1
Author Information
- Publication Type:Journal Article
- Keywords: bone remodeling; ferroptosis susceptibility; lipid peroxidation; mitochondrial metabolism; iron homeostasis
- From: Progress in Biochemistry and Biophysics 2026;53(10):2739-2752
- CountryChina
- Language:Chinese
- Abstract: Bone remodeling is essential for maintaining skeletal integrity and mineral homeostasis and depends on the coordinated activities of osteoclasts, osteoblasts, and osteocytes. Osteoclast-mediated bone resorption must remain closely coupled with osteoblast-mediated bone formation, while osteocytes continuously sense mechanical loading and changes in the local and systemic environment. Reactive oxygen species are involved in these physiological processes, particularly in the regulation of osteoclast differentiation and osteoblast function. Once oxidative stress exceeds the capacity of cellular antioxidant systems, however, this balance may be disturbed, leading to enhanced bone resorption, impaired bone formation, and deterioration of bone quality. In recent years, ferroptosis has attracted increasing attention in studies of bone metabolism. Ferroptosis is characterized by iron-dependent accumulation of lipid peroxides, but ferroptosis-related alterations in bone tissue may occur before obvious cell death becomes detectable. Changes in the labile iron pool, membrane lipid composition, antioxidant capacity, and mitochondrial metabolism can already influence the biological behavior of bone cells at an earlier stage. On this basis, ferroptosis susceptibility may provide a useful way to describe a reversible metabolic state in which cells become increasingly vulnerable to lipid peroxidation while widespread membrane damage and terminal cell death have not yet occurred. Such a state should not be identified by a single molecular marker. A more appropriate assessment would combine changes in intracellular iron handling, lipid peroxidation, antioxidant defense, cell viability, bone-cell function, and the response to ferroptosis-related interventions. Measurements of Fe2+ or the labile iron pool, C11-BODIPY oxidation, 4-HNE and MDA, GPX4 activity or expression, GSH/GSSG balance, LDH release, and PI staining may therefore provide complementary information when interpreted together with functional changes and rescue experiments. Several metabolic processes may contribute to the development of ferroptosis susceptibility in the bone. Disturbances in iron uptake, ferritin storage, ferritinophagy, and ferroportin-mediated iron export can increase the availability of redox-active iron. At the same time, ACSL4- and LPCAT3-dependent incorporation of polyunsaturated fatty acids into membrane phospholipids increases the pool of oxidizable lipid substrates. Reduced activity of the system Xc--GSH-GPX4 pathway further weakens the ability of cells to remove lipid hydroperoxides, while FSP1-CoQ and mitochondrial DHODH-CoQ systems provide additional antioxidant protection. Mitochondrial dysfunction, inflammation, and abnormalities in calcium-phosphate and endocrine regulation may further increase this metabolic pressure. Importantly, the consequences are unlikely to be identical among bone-cell populations. In osteoclasts, increased iron availability and oxidative stress may strengthen RANKL-NFATc1-associated differentiation and resorptive activity. In osteoblasts, persistent lipid peroxidation may interfere with RUNX2-related differentiation, collagen synthesis, matrix production, and mineralization before extensive cell loss occurs. Osteocytes, because of their long lifespan and specialized location within the mineralized matrix, may be particularly sensitive to chronic metabolic stress, resulting in impaired mechanosensing and disturbed RANKL- or FGF23-related feedback. Evidence linking these changes with osteoporosis, diabetes-related bone disorders, chronic kidney disease-mineral and bone disorder, inflammatory bone loss, and particle-induced osteolysis is increasing, although the strength of evidence differs among disease models. Changes in ROS, MDA, GPX4, or other individual indicators alone are insufficient to demonstrate ferroptosis-related susceptibility, and stronger conclusions require evidence of iron dependence, lipid peroxidation, temporal sequence, and reversibility. Emerging single-cell, spatial, proteomic, lipidomic, and metabolomic approaches may help identify susceptible cell populations and bone-remodeling regions more precisely, although the mineralized matrix and the effects of sample processing remain important technical limitations. Overall, ferroptosis susceptibility may represent an intermediate metabolic state linking disturbances in iron and redox homeostasis with progressive uncoupling of bone resorption and formation. Clarifying its cell-specific features, temporal development, and reversible window may improve our understanding of how chronic metabolic stress contributes to bone remodeling disorders and may also provide a basis for earlier and more targeted intervention.
