scholarly journals Parathyroid hormone-related peptide-depleted mice show abnormal epiphyseal cartilage development and altered endochondral bone formation.

1994 ◽  
Vol 126 (6) ◽  
pp. 1611-1623 ◽  
Author(s):  
N Amizuka ◽  
H Warshawsky ◽  
J E Henderson ◽  
D Goltzman ◽  
A C Karaplis
Keyword(s):  
Bone Formation ◽  
Embryonic Stem ◽  
Type Ii Collagen ◽  
Epiphyseal Plate ◽  
Epiphyseal Cartilage ◽  
Endochondral Bone Formation ◽  
Type Ii ◽  
Endochondral Bone ◽  
Cartilage Development ◽  
Calcified Cartilage

To elucidate the role of PTHrP in skeletal development, we examined the proximal tibial epiphysis and metaphysis of wild-type (PTHrP-normal) 18-19-d-old fetal mice and of chondrodystrophic litter mates homozygous for a disrupted PTHrP allele generated via homologous recombination in embryonic stem cells (PTHrP-depleted). In the PTHrP-normal epiphysis, immunocytochemistry showed PTHrP to be localized in chondrocytes within the resting zone and at the junction between proliferative and hypertrophic zones. In PTHrP-depleted epiphyses, a diminished [3H]thymidine-labeling index was observed in the resting and proliferative zones accounting for reduced numbers of epiphyseal chondrocytes and for a thinner epiphyseal plate. In the mutant hypertrophic zone, enlarged chondrocytes were interspersed with clusters of cells that did not hypertrophy, but resembled resting or proliferative chondrocytes. Although the overall content of type II collagen in the epiphyseal plate was diminished, the lacunae of these non-hypertrophic chondrocytes did react for type II collagen. Moreover, cell membrane-associated chondroitin sulfate immunoreactivity was evident on these cells. Despite the presence of alkaline phosphatase activity on these nonhypertrophic chondrocytes, the adjacent cartilage matrix did not calcify and their persistence accounted for distorted chondrocyte columns and sporadic distribution of calcified cartilage. Consequently, in the metaphysis, bone deposited on the irregular and sparse scaffold of calcified cartilage and resulted in mixed spicules that did not parallel the longitudinal axis of the tibia and were, therefore, inappropriate for bone elongation. Thus, PTHrP appears to modulate both the proliferation and differentiation of chondrocytes and its absence alters the temporal and spatial sequence of epiphyseal cartilage development and of subsequent endochondral bone formation necessary for normal elongation of long bones.

CARTILAGE-SPECIFIC OVEREXPRESSION OF C-PROPEPTIDE OF TYPE II COLLAGEN AFFECTED MATRIX MINERALIZATION IN TRANSGENIC MICE

2003 ◽  
Vol 07 (03n04) ◽  
pp. 183-189
Author(s):  
Yoshito Matsui ◽  
Ken Nakata ◽  
Eijiro Adachi ◽  
Noriyuki Tsumaki ◽  
Tomoatsu Kimura ◽  
...  
Keyword(s):  
Bone Formation ◽  
Transgenic Mice ◽  
Growth Plate ◽  
Type Ii Collagen ◽  
Whole Body ◽  
Endochondral Bone Formation ◽  
Type Ii ◽  
Endochondral Bone ◽  
Matrix Mineralization ◽  
Growth Plate Cartilage

The C-propeptide of type II collagen (CppII) is cleaved from the procollagen molecule at the time of extracellular secretion from chondrocytes, and was reported to localize in the lower hypertrophic zone of the growth plate cartilage. In the present study, the in vivo role of CppII in the process of endochondral bone formation was investigated by cartilage-specific overexpression of CppII in transgenic mice. Two independent lines of transgenic mice were obtained and they showed mild skeletal dysplasia, as evidenced by morphometric measurement of skeletal bones. Whole body staining revealed delayed mineralization of embryonic endochondral bones, including occipital bone and vertebral bodies. Histological sections showed reduced area of mineralization and scattered chondrocyte hypertrophy in the lower part of growth plate cartilage in the embryonic long bones. Immuno-electron micrographs demonstrated that CppII co-localized with collagen fibrils in the extracellular matrix of the cartilage. Taken together, these results indicate that overexpression of CppII affected endochondral bone formation by negatively regulating the matrix mineralization.

scholarly journals On the role of type IX collagen in the extracellular matrix of cartilage: type IX collagen is localized to intersections of collagen fibrils.

1986 ◽  
Vol 102 (5) ◽  
pp. 1931-1939 ◽  
Author(s):  
W Müller-Glauser ◽  
B Humbel ◽  
M Glatt ◽  
P Sträuli ◽  
K H Winterhalter ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Bone Formation ◽  
Tissue Distribution ◽  
Chicken Embryo ◽  
Polyclonal Antibodies ◽  
Type Ii Collagen ◽  
Endochondral Bone Formation ◽  
Type Ii ◽  
Endochondral Bone

The tissue distribution of type II and type IX collagen in 17-d-old chicken embryo was studied by immunofluorescence using polyclonal antibodies against type II collagen and a peptic fragment of type IX collagen (HMW), respectively. Both proteins were found only in cartilage where they were co-distributed. They occurred uniformly throughout the extracellular matrix, i.e., without distinction between pericellular, territorial, and interterritorial matrices. Tissues that undergo endochondral bone formation contained type IX collagen, whereas periosteal and membranous bones were negative. The thin collagenous fibrils in cartilage consisted of type II collagen as determined by immunoelectron microscopy. Type IX collagen was associated with the fibrils but essentially was restricted to intersections of the fibrils. These observations suggested that type IX collagen contributes to the stabilization of the network of thin fibers of the extracellular matrix of cartilage by interactions of its triple helical domains with several fibrils at or close to their intersections.

Fetal Jaw Movement Affects Condylar Cartilage Development

2005 ◽  
Vol 84 (5) ◽  
pp. 474-479 ◽  
Author(s):  
H. Habib ◽  
T. Hatta ◽  
J. Udagawa ◽  
L. Zhang ◽  
Y. Yoshimura ◽  
...  
Keyword(s):  
Bone Formation ◽  
Mandibular Condyle ◽  
Hypertrophic Chondrocytes ◽  
Endochondral Bone Formation ◽  
Condylar Cartilage ◽  
Mechanical Factor ◽  
Endochondral Bone ◽  
Jaw Movement ◽  
Cartilage Development ◽  
Number Of Cells

Using a mouse exo utero system to examine the effects of fetal jaw movement on the development of condylar cartilage, we assessed the effects of restraint of the animals’ mouths from opening, by suture, at embryonic day (E)15.5. We hypothesized that pre-natal jaw movement is an important mechanical factor in endochondral bone formation of the mandibular condyle. Condylar cartilage was reduced in size, and the bone-cartilage margin was ill-defined in the sutured group at E18.5. Volume, total number of cells, and number of 5-bromo-2′-deoxyuridine-positive cells in the mesenchymal zone were lower in the sutured group than in the non-sutured group at E16.5 and E18.5. Hypertrophic chondrocytes were larger, whereas fewer apoptotic chondrocytes and osteoclasts were observed in the hypertrophic zone in the sutured group at E18.5. Analysis of our data revealed that restricted fetal TMJ movement influences the process of endochondral bone formation of condylar cartilage.

scholarly journals Constitutive E2F1 Overexpression Delays Endochondral Bone Formation by Inhibiting Chondrocyte Differentiation

2003 ◽  
Vol 23 (10) ◽  
pp. 3656-3668 ◽  
Author(s):  
Blanca Scheijen ◽  
Marieke Bronk ◽  
Tiffany van der Meer ◽  
René Bernards
Keyword(s):  
Bone Formation ◽  
Endochondral Ossification ◽  
Bone Growth ◽  
Late Phase ◽  
Type Ii Collagen ◽  
Endochondral Bone Formation ◽  
Nodule Formation ◽  
Chondrocyte Differentiation ◽  
Endochondral Bone ◽  
Chondrocyte Maturation

ABSTRACT Longitudinal bone growth results from endochondral ossification, a process that requires proliferation and differentiation of chondrocytes. It has been shown that proper endochondral bone formation is critically dependent on the retinoblastoma family members p107 and p130. However, the precise functional roles played by individual E2F proteins remain poorly understood. Using both constitutive and conditional E2F1 transgenic mice, we show that ubiquitous transgene-driven expression of E2F1 during embryonic development results in a dwarf phenotype and significantly reduced postnatal viability. Overexpression of E2F1 disturbs chondrocyte maturation, resulting in delayed endochondral ossification, which is characterized by reduced hypertrophic zones and disorganized growth plates. Employing the chondrogenic cell line ATDC5, we investigated the effects of enforced E2F expression on the different phases of chondrocyte maturation that are normally required for endochondral ossification. Ectopic E2F1 expression strongly inhibits early- and late-phase differentiation of ATDC5 cells, accompanied by diminished cartilage nodule formation as well as decreased type II collagen, type X collagen, and aggrecan gene expression. In contrast, overexpression of E2F2 or E2F3a results in only a marginal delay of chondrocyte maturation, and increased E2F4 levels have no effect. These data are consistent with the notion that E2F1 is a regulator of chondrocyte differentiation.

scholarly journals Ablation of Ephrin B2 in Col2 Expressing Cells Delays Fracture Repair

Endocrinology ◽  
2020 ◽  
Vol 161 (12) ◽  
Author(s):  
Yongmei Wang ◽  
Lin Ling ◽  
Faming Tian ◽  
Sun Hee Won Kim ◽  
Sunita Ho ◽  
...  
Keyword(s):  
Bone Formation ◽  
Cell Activation ◽  
Bone Development ◽  
Type Ii Collagen ◽  
Fracture Site ◽  
Fracture Repair ◽  
Endochondral Bone Formation ◽  
Endochondral Bone ◽  
Intramembranous Bone ◽  
Endothelial Growth Factor

Abstract Ephrin B2 is critical for endochondral bone development. In this study, we investigated its role in fracture repair by deleting ephrin B2 in type II collagen (Col.2) expressing cells. We used a nonstable tibia fracture model to evaluate fracture repair at 3 sites: intramembranous bone formation, endochondral bone formation, and intramedullary bone formation. We observed that during fracture repair, deletion of ephrin B2 impaired periosteal stem cell activation, inhibited their proliferation, decreased their survival, and blocked their differentiation into osteoblasts and chondrocytes. In addition, deletion of ephrin B2 decreased vascular endothelial growth factor production as well as vascular invasion into the fracture site. These changes led to reduced cartilage to bone conversion in the callus with decreased new bone formation, resulting in impaired fracture repair. Our data indicate that ephrin B2 in Col2-expressing cells is a critical regulator of fracture repair, pointing to a new and potentially targetable mechanism to enhance fracture repair.

scholarly journals The culture microenvironment of juvenile idiopathic arthritis synovial fibroblasts is favorable for endochondral bone formation through BMP4 and repressed by chondrocytes

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Megan M. Simonds ◽  
Amanda R. Schlefman ◽  
Suzanne M. McCahan ◽  
Kathleen E. Sullivan ◽  
Carlos D. Rose ◽  
...  
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Bone Formation ◽  
Synovial Fibroblasts ◽  
Conditioned Media ◽  
Endochondral Bone Formation ◽  
Endochondral Bone ◽  
Member Gene ◽  
Bmp Antagonist ◽  
Fibroblast Like Synoviocytes ◽  
Tgfβ Superfamily

Abstract Background We examined influences of conditioned media from chondrocytes (Ch) on juvenile idiopathic arthritis synovial fibroblasts (JFLS) and potential for JFLS to undergo endochondral bone formation (EBF). Methods Primary cells from three control fibroblast-like synoviocytes (CFLS) and three JFLS were cultured in Ch-conditioned media and compared with untreated fibroblast-like synoviocytes (FLS). RNA was analyzed by ClariomS microarray. FLS cells cultured in conditioned media were exposed to either TGFBR1 inhibitor LY3200882 or exogenous BMP4 and compared with FLS cultured in conditioned media from Ch (JFLS-Ch). Media supernatants were analyzed by ELISA. Results In culture, JFLS downregulate BMP2 and its receptor BMPR1a while upregulating BMP antagonists (NOG and CHRD) and express genes (MMP9, PCNA, MMP12) and proteins (COL2, COLX, COMP) associated with chondrocytes. Important TGFβ superfamily member gene expression (TGFBI, MMP9, COL1A1, SOX6, and MMP2) is downregulated when JFLS are cultured in Ch-conditioned media. COL2, COLX and COMP protein expression decreases in JFLS-Ch. BMP antagonist protein (NOG, CHRD, GREM, and FST) secretion is significantly increased in JFLS-Ch. Protein phosphorylation increases in JFLS-Ch exposed to exogenous BMP4, and chondrocyte-like phenotype is restored in BMP4 presence, evidenced by increased secretion of COL2 and COLX. Inhibition of TGFBR1 in JFLS-Ch results in overexpression of COL2. Conclusions JFLS are chondrocyte-like, and Ch-conditioned media can abrogate this phenotype. The addition of exogenous BMP4 causes JFLS-Ch to restore this chondrocyte-like phenotype, suggesting that JFLS create a microenvironment favorable for endochondral bone formation, thereby contributing to joint growth disturbances in juvenile idiopathic arthritis.

scholarly journals Intraflagellar transport is essential for endochondral bone formation

Development ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 307-316 ◽  
Author(s):  
C. J. Haycraft ◽  
Q. Zhang ◽  
B. Song ◽  
W. S. Jackson ◽  
P. J. Detloff ◽  
...  
Keyword(s):  
Bone Formation ◽  
Intraflagellar Transport ◽  
Endochondral Bone Formation ◽  
Endochondral Bone
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