Background: Previous studies have shown that Galectin-3, a member of lectin family, is expressed in developing cartilage in mouse embryo and also in growth plate of long bones.   Objective: In the present work, the expression pattern of Galectin-3 in normal and various grades of osteoarthritic (OA) human articular cartilage has been studied.   Methods: Using immunohistochemistry and standard we...

We examined the effect of fibroblast growth factor (FGF) on proteoglycan synthesis by rabbit costal chondrocyte cultures maintained on plastic tissue culture dishes. Low density rabbit costal chondrocyte cultures grown in the absence of FGF gave rise at confluency to a heterogeneous cell population composed of fibroblastic cells and poorly differentiated chondrocytes. When similar cultures were...

Introduction In the pursuit of developing an in vitro model for the study of chondrocyte metabolism and the development of osteoarthritis (OA), it is important to mimic as closely as possible the in vivo environment. It is well known that chondrocyte metabolism is affected by mechanical stimuli through cellular signaling pathways. Therefore, mechanical load is an integral part of the in vivo en...

Precise coordination of cell growth, proliferation and differentiation is essential for the development of multicellular organisms. Here, we report that although the mechanistic target of rapamycin complex 1 (mTORC1) activity is required for chondrocyte growth and proliferation, its inactivation is essential for chondrocyte differentiation. Hyperactivation of mTORC1 via TSC1 gene deletion in ch...

We examined the effect of recombinant human osteogenic protein-1 (OP-1, or bone morphogenetic protein-7), a member of the bone morphogenetic protein family, on growth and maturation of day 11, 15 and 17 chick sternal chondrocytes in high density monolayers, suspension and agarose cultures for up to 5 weeks. OP-1 dose-dependently (10-50 ng/ml) promoted chondrocyte maturation associated with enha...

Exact coordination of growth plate chondrocyte proliferation is necessary for normal endochondral bone development and growth. Here we show that PTHrP and TGFbeta control chondrocyte cell cycle progression and proliferation by stimulating signaling pathways that activate transcription from the cyclin D1 promoter. The TGFbeta pathway activates the transcription factor ATF-2, whereas PTHrP uses t...

OBJECTIVE To determine whether autophagy was involved in chondrocyte cells post Glucocorticoids (GCs) treatment. MATERIALS AND METHODS LC3-GFP reporter plasmid transfection and western blotting analysis were conducted to determine the autophagic vesicles and autophagy-associated molecules in the N1511 chondrocyte cells post dexamethasone (Dex) treatment. And the N1511 cell viability was also ...

Histone methyltransferases EZH1 and EZH2 catalyse the trimethylation of histone H3 at lysine 27 (H3K27), which serves as an epigenetic signal for chromatin condensation and transcriptional repression. Genome-wide associated studies have implicated EZH2 in the control of height and mutations in EZH2 cause Weaver syndrome, which includes skeletal overgrowth. Here we show that the combined loss of...

Sox5 and Sox6 encode Sry-related transcription factors that redundantly promote early chondroblast differentiation. Using mouse embryos with three or four null alleles of Sox5 and Sox6, we show that they are also essential and redundant in major steps of growth plate chondrocyte differentiation. Sox5 and Sox6 promote the development of a highly proliferating pool of chondroblasts between the ep...