Chondrocytes Play a Major Role in the Stimulation of Bone Growth by Thyroid Hormone

Thyroid hormone (T3) is required for postnatal skeletal growth. It exerts its effect by binding to nuclear receptors, TRs including TRα1 and TRβ1, which are present in most cell types. These cell types include chondrocytes and osteoblasts, the interactions of which are known to regulate endochondral bone formation. In order to analyze the respective functions of T3 stimulation in chondrocytes and osteoblasts during postnatal growth, we use Cre/loxP recombination to express a dominant-negative TRα1L400R mutant receptor in a cell-specific manner. Phenotype analysis revealed that inhibiting T3 response in chondrocytes is sufficient to reproduce the defects observed in hypothyroid mice, not only for cartilage maturation, but also for ossification and mineralization. TRα1L400R in chondrocytes also results in skull deformation. In the meantime, TRα1L400R expression in mature osteoblasts has no visible effect. Transcriptome analysis identifies a number of changes in gene expression induced by TRα1L400R in cartilage. These changes suggest that T3 normally cross talks with several other signaling pathways to promote chondrocytes proliferation, differentiation, and skeletal growth.

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Haploinsufficiency of osterix in chondrocytes impairs skeletal growth in mice

Physiological Genomics ◽

10.1152/physiolgenomics.00111.2013 ◽

2013 ◽

Vol 45 (19) ◽

pp. 917-923 ◽

Cited By ~ 12

Author(s):

Shaohong Cheng ◽

Weirong Xing ◽

Xin Zhou ◽

Subburaman Mohan

Keyword(s):

Bone Growth ◽

Skeletal Growth ◽

Endochondral Bone Formation ◽

Volumetric Bone Mineral Density ◽

Mineral Density ◽

Endochondral Bone ◽

Alizarin Red ◽

Adult Mice ◽

Elevated Expression ◽

Skeletal Phenotype

Osterix ( Osx) is essential for both intramembranous or endochondral bone formation. Osteoblast-specific ablation of Osx using Col1α1-Cre resulted in osteopenia, because of impaired osteoblast differentiation in adult mice. Since Osx is also known to be expressed in chondrocytes, we evaluated the role of Osx expressed in chondrocytes by examining the skeletal phenotype of mice with conditional disruption of Osx in Col2α1-expressing chondrocytes. Surprisingly, Cre-positive mice that were homozygous for Osx floxed alleles died after birth. Alcian blue and alizarin red staining revealed that the lengths of skeleton, femur, and vertebrae were reduced by 21, 26, and 14% ( P < 0.01), respectively, in the knockout (KO) compared with wild-type mice. To determine if haploid insufficiency of Osx in chondrocytes influenced postnatal skeletal growth, we compared skeletal phenotype of floxed heterozygous mice that were Cre-positive or Cre-negative. Body length was reduced by 8% ( P < 0.001), and areal BMD of total body, femur, and tibia was reduced by 5, 7, and 8% ( P < 0.05), respectively, in mice with conditional disruption of one allele of Osx in chondrocytes. Micro-CT showed reduced cortical volumetric bone mineral density and trabecular bone volume to total volume in the femurs of Osxflox/+; col2α1-Cre mice. Histological analysis revealed that the impairment of longitudinal growth was associated with disrupted growth plates in the Osxflox/+; col2α1-Cre mice. Primary chondrocytes isolated from KO embryos showed reduced expression of chondral ossification markers but elevated expression of chondrogenesis markers. Our findings indicate that Osx expressed in chondrocytes regulates bone growth in part by regulating chondrocyte hypertrophy.

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Prolactin inhibits the apoptosis of chondrocytes induced by serum starvation

Journal of Endocrinology ◽

10.1677/joe.1.06766 ◽

2006 ◽

Vol 189 (2) ◽

pp. R1-R8 ◽

Cited By ~ 18

Author(s):

C Zermeño ◽

J Guzmán-Morales ◽

Y Macotela ◽

G Nava ◽

F López-Barrera ◽

...

Keyword(s):

Articular Chondrocytes ◽

Cell Types ◽

Cartilage Degradation ◽

Chondrocyte Apoptosis ◽

Heat Inactivation ◽

Serum Starvation ◽

Endochondral Bone Formation ◽

Endochondral Bone ◽

Therapeutic Value ◽

Apoptotic Effect

The apoptosis of chondrocytes plays an important role in endochondral bone formation and in cartilage degradation during aging and disease. Prolactin (PRL) is produced in chondrocytes and is known to promote the survival of various cell types. Here we show that articular chondrocytes from rat postpubescent and adult cartilage express the long form of the PRL receptor as revealed by immunohistochemistry of cartilage sections and by RT-PCR and Western blot analyses of the isolated chondrocytes. Furthermore, we demonstrate that PRL inhibits the apoptosis of these same chondrocytes cultured in low-serum. Chondrocyte apoptosis was measured by hypodiploid DNA content determined by flow cytometry and by DNA fragmentation evaluated by the ELISA and the TUNEL methods. The anti-apoptotic effect of PRL was dose-dependent and was prevented by heat inactivation. These data demonstrate that PRL can act as a survival factor for chondrocytes and that it has potential preventive and therapeutic value in arthropathies characterized by cartilage degradation.

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Circulating C-Type Natriuretic Peptide (CNP) Rescues Chondrodysplastic CNP Knockout Mice from Their Impaired Skeletal Growth and Early Death

Endocrinology ◽

10.1210/en.2010-0078 ◽

2010 ◽

Vol 151 (9) ◽

pp. 4381-4388 ◽

Cited By ~ 18

Author(s):

Toshihito Fujii ◽

Yasato Komatsu ◽

Akihiro Yasoda ◽

Eri Kondo ◽

Tetsuro Yoshioka ◽

...

Keyword(s):

Body Weight ◽

Natriuretic Peptide ◽

Knockout Mice ◽

Bone Growth ◽

Therapeutic Potential ◽

Body Weight Gain ◽

Early Death ◽

Systemic Administration ◽

Skeletal Growth ◽

Endochondral Bone

C-type natriuretic peptide (CNP) is a potent stimulator of endochondral bone growth through a subtype of membranous guanylyl cyclase receptor, GC-B. Although its two cognate natriuretic peptides, ANP and BNP, are cardiac hormones produced from heart, CNP is thought to act as an autocrine/paracrine regulator. To elucidate whether systemic administration of CNP would be a novel medical treatment for chondrodysplasias, for which no drug therapy has yet been developed, we investigated the effect of circulating CNP by using the CNP transgenic mice with an increased circulating CNP under the control of human serum amyloid P component promoter (SAP-Nppc-Tg mice). SAP-Nppc-Tg mice developed prominent overgrowth of bones formed through endochondral ossification. In organ culture experiments, the growth of tibial explants of SAP-Nppc-Tg mice was not changed from that of their wild-type littermates, exhibiting that the stimulatory effect on endochondral bone growth observed in SAP-Nppc-Tg mice is humoral. Then we crossed chondrodysplastic CNP-depleted mice with SAP-Nppc-Tg mice. Impaired endochondral bone growth in CNP knockout mice were considerably and significantly recovered by increased circulating CNP, followed by the improvement in not only their longitudinal growth but also their body weight. In addition, the mortality of CNP knockout mice was greatly decreased by circulating CNP. Systemic administration of CNP might have therapeutic potential against not only impaired skeletal growth but also other aspects of impaired growth including impaired body weight gain in patients suffering from chondrodysplasias and might resultantly protect them from their early death.

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ADAMTS-7, a Direct Target of PTHrP, Adversely Regulates Endochondral Bone Growth by Associating with and Inactivating GEP Growth Factor

Molecular and Cellular Biology ◽

10.1128/mcb.00056-09 ◽

2009 ◽

Vol 29 (15) ◽

pp. 4201-4219 ◽

Cited By ~ 69

Author(s):

Xiao-Hui Bai ◽

Da-Wei Wang ◽

Li Kong ◽

Yan Zhang ◽

Yi Luan ◽

...

Keyword(s):

Extracellular Matrix ◽

Growth Factor ◽

Bone Formation ◽

Proteolytic Activity ◽

Bone Growth ◽

Endochondral Bone Formation ◽

Chondrocyte Differentiation ◽

Growth Plate Chondrocytes ◽

Endochondral Bone ◽

Direct Target

ABSTRACT ADAMTS-7, a metalloproteinase that belongs to ADAMTS family, is important for the degradation of cartilage extracellular matrix proteins in arthritis. Herein we report that ADAMTS-7 is upregulated during chondrocyte differentiation and demonstrates the temporal and spatial expression pattern during skeletal development. ADAMTS-7 potently inhibits chondrocyte differentiation and endochondral bone formation, and this inhibition depends on its proteolytic activity. The cysteine-rich domain of ADAMTS-7 is required for its interaction with the extracellular matrix, and the C-terminal four-thrombospondin motifs are necessary for its full proteolytic activity and inhibition of chondrocyte differentiation. ADAMTS-7 is an important target of canonical PTHrP signaling, since (i) PTHrP induces ADAMTS-7, (ii) ADAMTS-7 is downregulated in PTHrP null mutant (PTHrP−/−) growth plate chondrocytes, and (iii) blockage of ADAMTS-7 almost abolishes PTHrP-mediated inhibition of chondrocyte hypertrophy and endochondral bone growth. ADAMTS-7 associates with granulin-epithelin precursor (GEP), an autocrine growth factor that has been implicated in tissue regeneration, tumorigenesis, and inflammation. In addition, ADAMTS-7 acts as a new GEP convertase and neutralizes GEP-stimulated endochondral bone formation. Collectively, these findings demonstrate that ADAMTS-7, a direct target of PTHrP signaling, negatively regulates endochondral bone formation by associating with and inactivating GEP chondrogenic growth factor.

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Constitutive E2F1 Overexpression Delays Endochondral Bone Formation by Inhibiting Chondrocyte Differentiation

Molecular and Cellular Biology ◽

10.1128/mcb.23.10.3656-3668.2003 ◽

2003 ◽

Vol 23 (10) ◽

pp. 3656-3668 ◽

Cited By ~ 28

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.

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Cooperation between p27 and p107 during Endochondral Ossification Suggests a Genetic Pathway Controlled by p27 and p130

Molecular and Cellular Biology ◽

10.1128/mcb.02431-06 ◽

2007 ◽

Vol 27 (14) ◽

pp. 5161-5171 ◽

Cited By ~ 16

Author(s):

Nancy Yeh ◽

Jeffrey P. Miller ◽

Tripti Gaur ◽

Terence D. Capellini ◽

Janko Nikolich-Zugich ◽

...

Keyword(s):

Ex Vivo ◽

Gene Families ◽

Cell Types ◽

Mutant Mice ◽

Endochondral Bone Formation ◽

Cell Type ◽

Mouse Development ◽

Ectopic Ossification ◽

Endochondral Bone ◽

Chondrocyte Maturation

ABSTRACT Pocket proteins and cyclin-dependent kinase (CDK) inhibitors negatively regulate cell proliferation and can promote differentiation. However, which members of these gene families, which cell type they interact in, and what they do to promote differentiation in that cell type during mouse development are largely unknown. To identify the cell types in which p107 and p27 interact, we generated compound mutant mice. These mice were null for p107 and had a deletion in p27 that prevented its binding to cyclin-CDK complexes. Although a fraction of these animals survived into adulthood and looked similar to single p27 mutant mice, a larger number of animals died at birth or within a few weeks thereafter. These animals displayed defects in chondrocyte maturation and endochondral bone formation. Proliferation of chondrocytes was increased, and ectopic ossification was observed. Uncommitted mouse embryo fibroblasts could be induced into the chondrocytic lineage ex vivo, but these cells failed to mature normally. These results demonstrate that p27 carries out overlapping functions with p107 in controlling cell cycle exit during chondrocyte maturation. The phenotypic similarities between p107 −/− p27 D51/D51 and p107 −/− p130 −/− mice and the cells derived from them suggest that p27 and p130 act in an analogous pathway during chondrocyte maturation.

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Juvenile idiopathic arthritis fibroblast-like synoviocytes influence chondrocytes to alter BMP antagonist expression demonstrating an interaction between the two prominent cell types involved in endochondral bone formation

Pediatric Rheumatology ◽

10.1186/s12969-020-00483-0 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Megan M. Simonds ◽

Amanda R. Schlefman ◽

Suzanne M. McCahan ◽

Kathleen E. Sullivan ◽

Carlos D. Rose ◽

...

Keyword(s):

Juvenile Idiopathic Arthritis ◽

Synovial Cell ◽

Synovial Fibroblasts ◽

Cell Types ◽

Bmp Signaling ◽

Conditioned Media ◽

Endochondral Bone Formation ◽

Direct Role ◽

Endochondral Bone ◽

Tgfβ Receptors

Abstract Background To examine critical interactions between juvenile idiopathic arthritis synovial fibroblasts (JFLS) and chondrocytes (Ch), and their role in bony overgrowth seen in patients with juvenile idiopathic arthritis (JIA). Methods Control (CFLS) and JFLS were cultured in synoviocyte media containing recombinant BMP4. Ch were cultured in either CFLS or JFLS conditioned-media without stimulation. Media supernatants were analyzed by ELISA. RNA from conditioned media experiment was analyzed by ClariomS microarray. Results As expected, genes expressed in untreated JFLS and CFLS cultured in synoviocyte media were similar to each other and this expression differed from untreated Ch cultured in chondrocyte media. JFLS favor BMP ligand gene expression while downregulating TGFβ receptors’ expression. Noggin and chordin, antagonists with high affinity for BMP4, are JFLS- but not Ch-preferred regulators of BMP signaling. Compared to Ch, JFLS overexpress collagen X (COLX), a marker of chondrocyte hypertrophy. Exogenous BMP4 causes JFLS to significantly decrease expression of noggin and collagen II (COL2), a marker of chondrocyte proliferation, and causes overexpression of COLX and alkaline-phosphatase (ALP). Chondrocytes cultured in JFLS-conditioned media (Ch-JFLS) express BMP genes and favor chordin protein expression over other antagonists. Ch-JFLS have significantly increased expression of COL2 and significantly decreased expression of COLX. Conclusions These data suggest JFLS, in the presence of BMP4, undergo hypertrophy and that JFLS-conditioned media influence chondrocytes to become highly proliferative. To the authors’ knowledge, no prior study has shown that JFLS and chondrocytes play a direct role in the bony overgrowth in joints of patients with JIA and that BMPs or regulation of these growth factors influence the interaction between two prominent synovial cell types.

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XBP1S Induces GEP and Enhances Endochondral Bone Growth

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.1136 ◽

2014 ◽

Vol 926-930 ◽

pp. 1136-1139

Author(s):

Feng Jin Guo ◽

Rong Jiang ◽

Xiao Feng Han

Keyword(s):

Growth Factor ◽

Bone Formation ◽

Bone Growth ◽

Ex Vivo ◽

Skeletal Development ◽

Endochondral Bone Formation ◽

Chondrocyte Differentiation ◽

Endochondral Bone ◽

Temporal And Spatial

We previously reported that transcription factor XBP1S is upregulated during chondrocyte differentiation and demonstrates the temporal and spatial expression pattern during skeletal development. Herein, we found that XBP1S stimulates chondrocyte differentiation from mesenchymal stem cells in vitro and endochondral ossification ex vivo. In addition, XBP1S activates granulin-epithelin precursor (GEP), a growth factor known to stimulate chondrogenesis, then enhances GEP-stimulated chondrogenesis and endochondral bone formation. Collectively, these findings demonstrate that XBP1S positively regulates endochondral bone formation by activating GEP chondrogenic growth factor.

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The CREB family of activators is required for endochondral bone development

Development ◽

10.1242/dev.128.4.541 ◽

2001 ◽

Vol 128 (4) ◽

pp. 541-550

Author(s):

F. Long ◽

E. Schipani ◽

H. Asahara ◽

H. Kronenberg ◽

M. Montminy

Keyword(s):

Transgenic Mice ◽

Bone Development ◽

Dominant Negative ◽

Endochondral Bone Formation ◽

Wild Type ◽

Growth Plate Chondrocytes ◽

Chondrocyte Proliferation ◽

Endochondral Bone ◽

Proliferative Zone ◽

Distinct Signaling Pathway

We have evaluated the importance of the CREB family of transcriptional activators for endochondral bone formation by expressing a potent dominant negative CREB inhibitor (A-CREB) in growth plate chondrocytes of transgenic mice. A-CREB transgenic mice exhibited short-limbed dwarfism and died minutes after birth, apparently due to respiratory failure from a diminished rib cage circumference. Consistent with the robust Ser133 phosphorylation and, hence, activation of CREB in chondrocytes within the proliferative zone of wild-type cartilage during development, chondrocytes in A-CREB mutant cartilage exhibited a profound decrease in proliferative index and a delay in hypertrophy. Correspondingly, the expression of certain signaling molecules in cartilage, most notably the Indian hedgehog (Ihh) receptor patched (Ptch), was lower in A-CREB expressing versus wild-type chondrocytes. CREB appears to promote Ptch expression in proliferating chondrocytes via an Ihh-independent pathway; phospho-CREB levels were comparable in cartilage from Ihh(−/−) and wild-type mice. These results demonstrate the presence of a distinct signaling pathway in developing bone that potentiates Ihh signaling and regulates chondrocyte proliferation, at least in part, via the CREB family of activators.

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Short Rib Polydactyly Syndrome Type III: Histopathogenesis of the Skeletal Phenotype

Pediatric and Developmental Pathology ◽

10.1007/s10024-001-0122-2 ◽

2002 ◽

Vol 5 (1) ◽

pp. 91-96 ◽

Cited By ~ 8

Author(s):

Alessandro Corsi ◽

Mara Riminucci ◽

Mario Roggini ◽

Paolo Bianco

Keyword(s):

Morphological Study ◽

Bone Growth ◽

Tissue Level ◽

Endochondral Bone Formation ◽

Syndrome Type ◽

Endochondral Bone ◽

Growth Plates ◽

Type Iii ◽

Skeletal Phenotype ◽

Short Rib Polydactyly Syndrome

A morphological study of the skeletal system in a case of short rib polydactyly syndrome type III (SRPS-III) documented a “bajonet” deformity of the ribs for misalignment and overlap of cartilaginous and bony ends. This deformity resulted from a ‘tandem’ change in endochondral bone formation that is, arrested orthotopic cartilage maturation and etherotopic perichondral cartilage differention and ossification. At the cartilaginous end, cartilage maturation and vascular invasion were absent. At the bony end, longitudinal bone growth occurred by a perichondral ectopic growth plate. ‘Miniature’ versions of this ‘tandem’ change were also demonstrated in the long bones of the limbs and included focally arrested orthotopic cartilage maturation at the growth plates, perichondral cartilage differentiation, and ossification within cartilage canals. Our morphological study indicates that a generalized loss of syncrony in cartilage removal and osteogenic differentiation occurs in all growth plates, albeit with varied expressivity, and represents, at tissue level, the mechanism by which the SRPS-III skeletal phenotype develops.

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