Signaling
The molecular switches that make or break the chondrocyte: SOX9, TGF-beta, IHH and PTHrP, mechanotransduction, and the transcription factor hierarchy of the growth plate.
Selenoprotein S (SelS) deficiency in chondrocytes activates Wnt/beta-catenin signaling and disrupts terminal differentiation; selenium deficiency linked to cartilage damage and osteoarticular disease; implicates SelS as a regulator of chondrocyte maturation via the Wnt pathway.
TGF-beta stabilizes Sox9 via p38 and Smad2/3; both pathways required independently. SOX9 protein level is a TGF-beta-dependent outcome.
Sox9 up-regulates PTHrP expression in association with Ihh/Gli2 signaling; the Ihh-PTHrP-Sox9 loop paces hypertrophic differentiation.
Comprehensive review: Sox9, Runx2, Ihh, PTHrP, TGF-beta, BMP, FGF, and Wnt signaling in chondrocyte fate decisions from mesenchymal condensation through hypertrophy.
Sox9 maintains chondrocyte fate; Runx2 drives hypertrophy; Ihh-PTHrP forms a feedback loop regulating the pace of hypertrophic differentiation.
Mechanotransduction modeled stoichiometrically under cyclical load; nitrogen availability is the primary constraint on matrix protein synthesis.
TGF-beta superfamily members show distinct expression profiles in chondral versus endochondral cartilage; Smad1/5/9 is the endochondral-specific branch.
Zone-intrinsic mechanotransduction confirmed: superficial and deep zone chondrocytes respond differently to the same oscillatory load.
Benninghoff arcade model confirmed at high resolution; tangential collagen orientation in superficial zone quantified.
Hypertrophic chondrocytes are a source of skeletal stem and progenitor cells, osteoblasts, and adipocytes; extends the 2014 lineage revision.
One of three 2014 lineage-tracing studies overturning apoptosis dogma; Col10a1-expressing hypertrophic chondrocytes contribute ~60 percent of mature osteoblasts.
Shear stress from fluid flow is a key variable in bioreactor design; chondrocytes are highly sensitive to mechanosensation
Computational framework captures continuous mechanical interactions between chondrocytes and pericellular matrix under loading
Review: physis integrates stem-like progenitor activity, clonal expansion, matrix remodeling, vascular invasion, and bone replacement
Eight preHTC subtypes identified; CRIP1+ subtype is most expanded in OA weight-bearing regions; FN1 signaling elevated
scRNA-seq of 6 normal and 5 OA samples; superficial zone cells show highest catabolic protease and senescence gene expression
Resting zone of the human growth plate holds subpopulations with quiescent stem cell features.
Review of how compression is sensed and signalled by chondrocytes, and what that means for scaffold design.
Epigenetic axis DOT1L to ITCH to AURKA restrains matrix degradation in OA chondrocytes.
Natural compound eugenol sustains ECM homeostasis in chondrocytes by balancing ALK1 and ALK5 arms of TGF-beta signaling.
Plant lignan SDG reduces IL-1beta-driven inflammation in OA chondrocytes through ERBB2-coupled JAK2/STAT3 suppression.
Pararamosis, a tropical arthritis from ant venom, drives macrophage-to-chondrocyte IL-1beta signaling; model for studying cytokine-driven cartilage destruction.
Glucocorticoid-induced methylation shuts off MALAT1, unleashing miR-124-3p to repress LPCAT3 and trigger ferroptosis in growth plate chondrocytes.
Lactate accumulation in the OA joint drives lactylation of histone and non-histone proteins, shifting chondrocytes toward catabolic and senescent states and sustaining inflammation. A metabolic axis on top of the usual cytokine story.
lncRNA OIP5-AS1 sequesters miR-223-3p, relieving FoxO3 repression and protecting chondrocytes from apoptosis in TMJ osteoarthritis; extends the lncRNA-sponge signaling pattern to a joint outside the knee.
Review arguing that mitochondrial dysfunction is a unifying mechanism across cartilage, bone, and muscle degeneration; frames mitochondrial quality control as a precision target for chondrocytes and other musculoskeletal cell types.
Cyclodextrin-based metal-organic framework targeted to macrophages rescues efferocytosis and redox balance in the TMJ OA joint, promoting osteochondral repair; chondrocyte protection is downstream of macrophage polarisation.