TBX1 Regulates Chondrocyte Maturation in the Spheno-occipital Synchondrosis

2020 ◽  
Vol 99 (10) ◽  
pp. 1182-1191 ◽  
Author(s):  
N. Funato ◽  
D. Srivastava ◽  
S. Shibata ◽  
H. Yanagisawa
Keyword(s):  
Digeorge Syndrome ◽  
Endochondral Ossification ◽  
Transcriptional Activity ◽  
Ectopic Expression ◽  
Chondrocyte Differentiation ◽  
Craniofacial Skeleton ◽  
Chondrocyte Maturation ◽  
Expression Of Genes ◽  
Growth Center ◽  
Deficient Mice

The synchondrosis in the cranial base is an important growth center for the craniofacial region. Abnormalities in the synchondroses affect the development of adjacent regions, including the craniofacial skeleton. Here, we report that the transcription factor TBX1, the candidate gene for DiGeorge syndrome, is expressed in mesoderm-derived chondrocytes and plays an essential and specific role in spheno-occipital synchondrosis development by inhibiting the expression of genes involved in chondrocyte hypertrophy and osteogenesis. In Tbx1-deficient mice, the spheno-occipital synchondrosis was completely mineralized at birth. TBX1 interacts with RUNX2, a master molecule of osteoblastogenesis and a regulator of chondrocyte maturation, and suppresses its transcriptional activity. Indeed, deleting Tbx1 triggers accelerated mineralization due to accelerated chondrocyte differentiation, which is associated with ectopic expression of downstream targets of RUNX2 in the spheno-occipital synchondrosis. These findings reveal that TBX1 acts as a regulator of chondrocyte maturation and osteogenesis during the spheno-occipital synchondrosis development. Thus, the tight regulation of endochondral ossification by TBX1 is crucial for the normal progression of chondrocyte differentiation in the spheno-occipital synchondrosis.

scholarly journals Sox9 Family Members Negatively Regulate Maturation and Calcification of Chondrocytes through Up-Regulation of Parathyroid Hormone–related Protein

2009 ◽  
Vol 20 (21) ◽  
pp. 4541-4551 ◽  
Author(s):  
Katsuhiko Amano ◽  
Kenji Hata ◽  
Atsushi Sugita ◽  
Yoko Takigawa ◽  
Koichiro Ono ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Endochondral Ossification ◽  
Family Members ◽  
Chondrocyte Differentiation ◽  
Related Protein ◽  
Primary Chondrocytes ◽  
Chondrocyte Maturation ◽  
Parathyroid Hormone Related Protein ◽  
Pthrp Expression ◽  
Late Stages

Sox9 is a transcription factor that plays an essential role in chondrogenesis and has been proposed to inhibit the late stages of endochondral ossification. However, the molecular mechanisms underlying the regulation of chondrocyte maturation and calcification by Sox9 remain unknown. In this study, we attempted to clarify roles of Sox9 in the late stages of chondrocyte differentiation. We found that overexpression of Sox9 alone or Sox9 together with Sox5 and Sox6 (Sox5/6/9) inhibited the maturation and calcification of murine primary chondrocytes and up-regulated parathyroid hormone–related protein (PTHrP) expression in primary chondrocytes and the mesenchymal cell line C3H10T1/2. Sox5/6/9 stimulated the early stages of chondrocyte proliferation and development. In contrast, Sox5/6/9 inhibited maturation and calcification of chondrocytes in organ culture. The inhibitory effects of Sox5/6/9 were rescued by treating with anti-PTHrP antibody. Moreover, Sox5/6/9 bound to the promoter region of the PTHrP gene and up-regulated PTHrP gene promoter activity. Interestingly, we also found that the Sox9 family members functionally collaborated with Ihh/Gli2 signaling to regulate PTHrP expression and chondrocyte differentiation. Our results provide novel evidence that Sox9 family members mediate endochondral ossification by up-regulating PTHrP expression in association with Ihh/Gli2 signaling.

scholarly journals PRDM proteins control Wnt/β-catenin activity to regulate craniofacial chondrocyte differentiation

2021 ◽  
Author(s):  
Lomeli Carpio Shull ◽  
Hyun Min Kim ◽  
Ezra Lencer ◽  
James C Costello ◽  
Kenneth Jones ◽  
...  
Keyword(s):  
Birth Defects ◽  
Transcriptional Activity ◽  
Global Gene Expression ◽  
Chromatin Accessibility ◽  
Cartilage Defects ◽  
Chondrocyte Differentiation ◽  
Maturation Process ◽  
Craniofacial Skeleton ◽  
Congenital Birth Defects ◽  
Cartilage Differentiation

Cranial neural crest (NCC)-derived chondrocyte precursors undergo a dynamic differentiation and maturation process to establish a scaffold for subsequent bone formation, alterations in which contribute to congenital birth defects. Here, we demonstrate that transcription factor and histone methyltransferase proteins Prdm3 and Prdm16 control the differentiation switch of cranial NCCs to craniofacial cartilage. Loss of either results in hypoplastic and unorganized chondrocytes due to impaired cellular orientation and polarity. We show that PRDMs regulate cartilage differentiation by controlling the timing of Wnt/β-catenin activity in strikingly different ways: Prdm3 represses while Prdm16 activates global gene expression, though both by regulating Wnt enhanceosome activity and chromatin accessibility. Finally, we show that manipulating Wnt/β-catenin signaling pharmacologically or generating prdm3-/-;prdm16-/- double mutants rescues craniofacial cartilage defects. Our findings reveal upstream regulatory roles for Prdm3 and Prdm16 in cranial NCCs to control Wnt/β-catenin transcriptional activity during chondrocyte differentiation to ensure proper development of the craniofacial skeleton.

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.

Wnt/β-catenin Signaling Regulates Cranial Base Development and Growth

2008 ◽  
Vol 87 (3) ◽  
pp. 244-249 ◽  
Author(s):  
M. Nagayama ◽  
M. Iwamoto ◽  
A. Hargett ◽  
N. Kamiya ◽  
Y. Tamamura ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Wnt Signaling ◽  
Growth Plate ◽  
Endochondral Ossification ◽  
Cranial Base ◽  
Developmental Changes ◽  
Chondrocyte Hypertrophy ◽  
Chondrocyte Maturation ◽  
Wnt Proteins ◽  
Deficient Mice

Wnt proteins and β-catenin signaling regulate major processes during embryonic development, and we hypothesized that they regulate cranial base synchondrosis development and growth. To address this issue, we analyzed cartilage-specific β -catenin-deficient mice. Mutant synchondroses lacked typical growth plate zones, and endochondral ossification was delayed. In reciprocal transgenic experiments, cartilage overexpression of a constitutive active Lef1, a transcriptional mediator of Wnt/β-catenin signaling, caused precocious chondrocyte hypertrophy and intermingling of immature and mature chondrocytes. The developmental changes seen in β -catenin-deficient synchondroses were accompanied by marked reductions in Ihh and PTHrP as well as sFRP-1, an endogenous Wnt signaling antagonist and a potential Ihh signaling target. Thus, Wnt/β-catenin signaling is essential for cranial base development and synchondrosis growth plate function. This pathway promotes chondrocyte maturation and ossification events, and may exert this important role by dampening the effects of Ihh-PTHrP together with sFRP-1.

scholarly journals Altered TNSALP Expression and Phosphate Regulation Contribute to Reduced Mineralization in Mice Lacking Androgen Receptor

2008 ◽  
Vol 28 (24) ◽  
pp. 7354-7367 ◽  
Author(s):  
Hong-Yo Kang ◽  
Chih-Rong Shyr ◽  
Chiung-Kuei Huang ◽  
Meng-Yin Tsai ◽  
Hideo Orimo ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Bone Loss ◽  
Bone Formation ◽  
Target Genes ◽  
Ectopic Expression ◽  
Phosphate Regulation ◽  
Expression Of Genes ◽  
Intramembranous Bone ◽  
High Bone ◽  
Deficient Mice

ABSTRACT While androgen receptor (AR)-deficient mice developed osteopenia in endochondral bones due to the high bone turnover with increased bone resorption by osteoclasts, little is known about the mechanism of intramembranous bone loss contributed by AR in osteoblasts. Here, we discovered a dramatic decrease in the area of calcification, new bone, and the number of osteocytes in calvaria from AR-deficient mice related to a reduction in mineralization caused, in part, by the diminished activity of AR-deficient osteoblasts. Enforced AR expression in differentiated osteoblasts boosts mineralization while knockdown of AR expression prevents androgen-induced mineralization. We identified the tissue-nonspecific alkaline phosphatase (TNSALP) and several members of small integrin binding ligand N-linked glycoprotein (SIBLING) gene family as androgen target genes required for AR-mediated bone formation. We show that inorganic phosphate (Pi) levels and TNSALP activity increased in response to androgen/AR and Pi signals increase the expression and translocation of AR. The ectopic expression of TNSALP or Pi partially rescued the bone loss due to AR deficiency. Thus, androgen/AR signaling plays an essential role in bone formation by coordinating the expression of genes associated with phosphate regulation.

scholarly journals Drosophila Mi-2 Negatively Regulates dDREF by Inhibiting Its DNA-Binding Activity

2002 ◽  
Vol 22 (14) ◽  
pp. 5182-5193 ◽  
Author(s):  
Fumiko Hirose ◽  
Nobuko Ohshima ◽  
Eun-Jeong Kwon ◽  
Hideki Yoshida ◽  
Masamitsu Yamaguchi
Keyword(s):  
Dna Binding ◽  
Polytene Chromosomes ◽  
Ectopic Expression ◽  
Binding Activity ◽  
Mobility Shift ◽  
Interacting Protein ◽  
Reciprocal Regulation ◽  
Dna Binding Activity ◽  
Expression Of Genes ◽  
Biochemical Analyses

ABSTRACT Drosophila melanogaster DNA replication-related element (DRE) factor (dDREF) is a transcriptional regulatory factor required for the expression of genes carrying the 5′-TATCGATA DRE. dDREF has been reported to bind to a sequence in the chromatin boundary element, and thus, dDREF may play a part in regulating insulator activity. To generate further insights into dDREF function, we carried out a Saccharomyces cerevisiae two-hybrid screening with DREF polypeptide as bait and identified Mi-2 as a DREF-interacting protein. Biochemical analyses revealed that the C-terminal region of Drosophila Mi-2 (dMi-2) specifically binds to the DNA-binding domain of dDREF. Electrophoretic mobility shift assays showed that dMi-2 thereby inhibits the DNA-binding activity of dDREF. Ectopic expression of dDREF and dMi-2 in eye imaginal discs resulted in severe and mild rough-eye phenotypes, respectively, whereas flies simultaneously expressing both proteins exhibited almost-normal eye phenotypes. Half-dose reduction of the dMi-2 gene enhanced the DREF-induced rough-eye phenotype. Immunostaining of polytene chromosomes of salivary glands showed that dDREF and dMi-2 bind in mutually exclusive ways. These lines of evidence define a novel function of dMi-2 in the negative regulation of dDREF by its DNA-binding activity. Finally, we postulated that dDREF and dMi-2 may demonstrate reciprocal regulation of their functions.

A recombinant cottontail rabbit papillomavirus genome for ectopic expression of genes in cells infected with virus in vivo

2013 ◽  
Vol 187 (1) ◽  
pp. 110-113 ◽  
Author(s):  
Sonja Probst ◽  
Ekaterina Notz ◽  
Miriam Wolff ◽  
Julia Buehlmann ◽  
Frank Stubenrauch ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Cottontail Rabbit ◽  
Expression Of Genes ◽  
In Cells

16. Physiological effects of IDH1 loss-of-function on Chondrocyte Differentiation through Hedgehog Pathway upregulation

2018 ◽  
Author(s):  
Cassie Tyson
Keyword(s):  
Developmental Stages ◽  
Hedgehog Pathway ◽  
Chondrocyte Differentiation ◽  
Loss Of Function ◽  
Wild Type ◽  
Phenotypic Analysis ◽  
Growth Plate Chondrocytes ◽  
Idh Mutations ◽  
Cartilage Tumors ◽  
Deficient Mice

Cartilage tumors are the most common and terminal primary neoplasms in bone. Physiologically, bones formed through endochondral ossification are regulated by the Hedgehog pathway and Parathyroid hormone-like hormone feedback loop. The upregulation of the infamous Hedgehog pathway has been demonstrated in several non-cartilaginous neoplasms. Recently, frequent mutational events of isocitrate dehydrogenase1 (IDH1) were identified in cartilage tumors. In other neoplasms, IDH mutations produces an oncometabolite that can promote HIF1a activation, contributing to tumorigenesis. Currently, the role of IDH1 mutations in cartilage tumors remain unknown. Investigating the physiological aspect of IDH1proves useful in identifying novel therapeutic targets for cartilage tumors. IDH1 deficient and wild-type littermates, were harvested for forelimbs and hindlimbs at various developmental stages for phenotypic analysis via hematoxylin and eosin staining. Histological analysis demonstrated IDH1 homozygous deficient mice at embryonic stages exhibited dwarfism and an elongated layer of hypertrophic chondrocytes. This was verified via immunohistochemistry Type 10 Collagen staining and Quantitative PCR (qPCR) using the chondrocyte terminal differentiation marker Col10a1. Whole skeletons of IDH1 deficient mice were subjected to skeletal double staining which demonstrated delayed mineralization of underdeveloped IDH1 deficient mice contrasted with wild-type littermates. qPCR was performed to examine the status of chondrocyte differentiation through the Hedgehog pathway in cultured primarymouse growth plate chondrocytes. Interestingly, IDH1 deficient non-neoplastic cells revealed significant upregulation of Hedgehog target molecules in IDH1 deficient chondrocytes. As a result, the loss-offunction of IDH1 was identified as a potential impairment of chondrocyte differentiation and a factor towards chondrocyte tumorgenisis.

Dual action of sonic hedgehog on chondrocyte hypertrophy:retrovirus mediated ectopic sonic hedgehog expression in limb bud micromass culture induces novel cartilage nodules that are positive for alkaline phosphatase and type X collagen

1997 ◽  
Vol 110 (21) ◽  
pp. 2691-2701 ◽  
Author(s):  
N.S. Stott ◽  
C.M. Chuong
Keyword(s):  
Alkaline Phosphatase ◽  
Gene Family ◽  
Alcian Blue ◽  
Sonic Hedgehog ◽  
Ectopic Expression ◽  
Limb Bud ◽  
Blue Staining ◽  
Alcian Blue Staining ◽  
Type X Collagen ◽  
Chondrocyte Maturation

Members of the vertebrate hedgehog gene family (HH) are involved in patterning and modulation of differentiation. Recently it has been shown that ectopic expression of HH gene family members in vivo blocks chondrocyte maturation through activation of a parathyroid hormone related peptide (PTHrP) dependent negative regulatory loop in the perichondrium. However, the direct effect of HH on chondrocyte maturation has not been tested. Here, we studied the effect of retroviral overexpression of the chicken sonic hedgehog gene (Shh) on the growth and maturation of limb bud cells in micromass cultures. Shh is neither expressed nor required for the initiation of cellular condensation in normal micromass cultures. With Shh over-expression, micromass cultures developed novel tightly whorled nodules in addition to the normal Alcian Blue positive cartilage nodules. We characterized the new nodules and showed that they are strongly positive for alkaline phosphatase, enriched in type X collagen and weakly positive for Alcian Blue staining. Shh overexpression also increased cell proliferation, but this cannot account for the formation of the new nodules. This current study shows that misexpression of Shh in in vitro chondrogenic cultures promotes characteristics of hypertrophic chondrocytes. Thus HH has two complementary functions; a direct positive effect on chondrocyte hypertrophy in the absence of PTHrP pathway, and an indirect negative feedback loop through PTHrP to prevent other less differentiated chondrocytes from becoming hypertrophic. These two complementary actions of HH coordinate the progression of cartilage maturation.

scholarly journals Regulation of Steroid Hormone Receptors and Coregulators during the Cell Cycle Highlights Potential Novel Function in Addition to Roles as Transcription Factors

2016 ◽  
Vol 14 (1) ◽  
pp. nrs.14001 ◽  
Author(s):  
Yingfeng Zheng ◽  
Leigh C. Murphy
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Transcriptional Activity ◽  
Hormone Receptors ◽  
Steroid Receptors ◽  
Steroid Hormone ◽  
Steroid Hormone Receptors ◽  
Cycle Progression ◽  
Expression Of Genes ◽  
Cycle Regulation

Cell cycle progression is tightly controlled by several kinase families including Cyclin-Dependent Kinases, Polo-Like Kinases, and Aurora Kinases. A large amount of data show that steroid hormone receptors and various components of the cell cycle, including cell cycle regulated kinases, interact, and this often results in altered transcriptional activity of the receptor. Furthermore, steroid hormones, through their receptors, can also regulate the transcriptional expression of genes that are required for cell cycle regulation. However, emerging data suggest that steroid hormone receptors may have roles in cell cycle progression independent of their transcriptional activity. The following is a review of how steroid receptors and their coregulators can regulate or be regulated by the cell cycle machinery, with a particular focus on roles independent of transcription in G2/M.

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