scholarly journals Runx1 up-regulates chondrocyte to osteoblast lineage commitment and promotes bone formation by enhancing both chondrogenesis and osteogenesis

2020 ◽  
Vol 477 (13) ◽  
pp. 2421-2438 ◽  
Author(s):  
Chen-Yi Tang ◽  
Wei Chen ◽  
Yuan Luo ◽  
Jinjin Wu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Bone Formation ◽  
Osteoblast Differentiation ◽  
Lineage Commitment ◽  
Marker Genes ◽  
Endochondral Bone Formation ◽  
Bone Biology ◽  
Endochondral Bone ◽  
Hypertrophic Chondrocyte ◽  
Related Transcription Factor ◽  
Osteoblast Lineage

One of the fundamental questions in bone biology is where osteoblasts originate and how osteoblast differentiation is regulated. The mechanism underlying which factors regulate chondrocyte to osteoblast lineage commitment remains unknown. Our data showed that Runt-related transcription factor 1 (Runx1) is expressed at different stages of both chondrocyte and osteoblast differentiation. Runx1 chondrocyte-specific knockout (Runx1f/fCol2α1-cre) mice exhibited impaired cartilage formation, decreased bone density, and an osteoporotic phenotype. The expressions of chondrocyte differentiation regulation genes, including Sox9, Ihh, CyclinD1, PTH1R, and hypertrophic chondrocyte marker genes including Col2α1, Runx2, MMP13, Col10α1 in the growth plate were significantly decreased in Runx1f/fCol2α1-cre mice chondrocytes. Importantly, the expression of osteoblast differentiation regulation genes including Osx, Runx2, ATF4, and osteoblast marker genes including osteocalcin (OCN) and osteopontin (OPN) were significantly decreased in the osteoblasts of Runx1f/fCol2α1-cre mice. Notably, our data showed that osteoblast differentiation regulation genes and marker genes are also expressed in chondrocytes and the expressions of these marker genes were significantly decreased in the chondrocytes of Runx1f/fCol2α1-cre mice. Our data showed that chromatin immunoprecipitation (ChIP) and promoter mapping analysis revealed that Runx1 directly binds to the Indian hedgehog homolog (Ihh) promoter to regulate its expression, indicating that Runx1 directly regulates the transcriptional expression of chondrocyte genes. Collectively, we revealed that Runx1 signals chondrocyte to osteoblast lineage commitment and promotes endochondral bone formation through enhancing both chondrogenesis and osteogenesis genes expressions, indicating Runx1 may be a therapeutic target to enhance endochondral bone formation and prevent osteoporosis fractures.

scholarly journals Dmrt2 promotes transition of endochondral bone formation by linking Sox9 and Runx2

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Koichiro Ono ◽  
Kenji Hata ◽  
Eriko Nakamura ◽  
Shota Ishihara ◽  
Sachi Kobayashi ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Bone Formation ◽  
Skeletal Development ◽  
Endochondral Bone Formation ◽  
Chondrocyte Differentiation ◽  
Endochondral Bone ◽  
Chondrocyte Hypertrophy ◽  
Hypertrophic Chondrocyte ◽  
Delayed Initiation ◽  
Related Transcription Factor

AbstractEndochondral bone formation is fundamental for skeletal development. During this process, chondrocytes undergo multiple steps of differentiation and coordinated transition from a proliferating to a hypertrophic stage, which is critical to advance skeletal development. Here, we identified the transcription factor Dmrt2 (double-sex and mab-3 related transcription factor 2) as a Sox9-inducible gene that promotes chondrocyte hypertrophy in pre-hypertrophic chondrocytes. Epigenetic analysis further demonstrated that Sox9 regulates Dmrt2 expression through an active enhancer located 18 kb upstream of the Dmrt2 gene and that this enhancer’s chromatin status is progressively activated through chondrocyte differentiation. Dmrt2-knockout mice exhibited a dwarf phenotype with delayed initiation of chondrocyte hypertrophy. Dmrt2 augmented hypertrophic chondrocyte gene expression including Ihh through physical and functional interaction with Runx2. Furthermore, Dmrt2 deficiency reduced Runx2-dependent Ihh expression. Our findings suggest that Dmrt2 is critical for sequential chondrocyte differentiation during endochondral bone formation and coordinates the transcriptional network between Sox9 and Runx2.

scholarly journals Regulation of terminal hypertrophic chondrocyte differentiation in Prmt5 mutant mice modeling infantile idiopathic scoliosis

2019 ◽  
Author(s):  
Zhaoyang Liu ◽  
Janani Ramachandran ◽  
Steven A Vokes ◽  
Ryan S Gray
Keyword(s):  
Bone Formation ◽  
Idiopathic Scoliosis ◽  
Age Of Onset ◽  
Endochondral Bone Formation ◽  
Chondrocyte Differentiation ◽  
Respiratory Compromise ◽  
Endochondral Bone ◽  
Hypertrophic Chondrocyte ◽  
Infantile Idiopathic Scoliosis ◽  
Adult Spine

ABSTRACTIdiopathic scoliosis (IS) is the most common type of musculoskeletal defect effecting children and is classified by age of onset, location, and degree of spine curvature. Although rare, the onset of IS during infancy is the more severe and rapidly progressive form of the disease, leading to increased mortality due to significant respiratory compromise. The pathophysiology of IS, in particular for infantile IS, remain elusive. Here, we show that PRMT5 is critical for the regulation of terminal hypertrophic chondrocyte differentiation in the spine and models infantile IS in mouse. Conditional ablation of PRMT5 in osteochondral progenitors led to impaired terminal hypertrophic chondrocyte differentiation and asymmetric defects of endochondral bone formation in the perinatal spine. Analysis of several markers of endochondral ossification revealed increased COLX and Ihh expression and a dramatic reduction of Mmp13 and RUNX2 expression in the intervertebral disc and vertebral growth plate. Furthermore, we demonstrate that PRMT5 function in committed chondrogenic lineages is required for regulation of COLX expression in the adult spine. Together, our results establish PRMT5 as a critical regulator of hypertrophic chondrocyte differentiation and endochondral bone formation in spine development and maintenance.

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

scholarly journals Osteoblast‐Specific Loss of IGF1R Signaling Results in Impaired Endochondral Bone Formation During Fracture Healing

2015 ◽  
Vol 30 (9) ◽  
pp. 1572-1584 ◽  
Author(s):  
Tao Wang ◽  
Yongmei Wang ◽  
Alicia Menendez ◽  
Chak Fong ◽  
Muriel Babey ◽  
...  
Keyword(s):  
Bone Formation ◽  
Fracture Healing ◽  
Endochondral Bone Formation ◽  
Endochondral Bone ◽  
Specific Loss ◽  
Igf1r Signaling

scholarly journals Conditional Deletion of Prolyl Hydroxylase Domain-Containing Protein 2 (Phd2) Gene Reveals Its Essential Role in Chondrocyte Function and Endochondral Bone Formation

Endocrinology ◽  
2016 ◽  
Vol 157 (1) ◽  
pp. 127-140 ◽  
Author(s):  
Shaohong Cheng ◽  
Weirong Xing ◽  
Sheila Pourteymoor ◽  
Jan Schulte ◽  
Subburaman Mohan
Keyword(s):  
Bone Formation ◽  
Growth Plate ◽  
Prolyl Hydroxylase ◽  
Conditional Knockout ◽  
Hypertrophic Chondrocytes ◽  
Endochondral Bone Formation ◽  
Bone Surface ◽  
Endochondral Bone ◽  
Prolyl Hydroxylase Domain

Abstract The hypoxic growth plate cartilage requires hypoxia-inducible factor (HIF)-mediated pathways to maintain chondrocyte survival and differentiation. HIF proteins are tightly regulated by prolyl hydroxylase domain-containing protein 2 (Phd2)-mediated proteosomal degradation. We conditionally disrupted the Phd2 gene in chondrocytes by crossing Phd2 floxed mice with type 2 collagen-α1-Cre transgenic mice and found massive increases (>50%) in the trabecular bone mass of long bones and lumbar vertebra of the Phd2 conditional knockout (cKO) mice caused by significant increases in trabecular number and thickness and reductions in trabecular separation. Cortical thickness and tissue mineral density at the femoral middiaphysis of the cKO mice were also significantly increased. Dynamic histomorphometric analyses revealed increased longitudinal length and osteoid surface per bone surface in the primary spongiosa of the cKO mice, suggesting elevated conversion rate from hypertrophic chondrocytes to mineralized bone matrix as well as increased bone formation in the primary spongiosa. In the secondary spongiosa, bone formation measured by mineralizing surface per bone surface and mineral apposition rate were not changed, but resorption was slightly reduced. Increases in the mRNA levels of SRY (sex determining region Y)-box 9, osterix (Osx), type 2 collagen, aggrecan, alkaline phosphatase, bone sialoprotein, vascular endothelial growth factor, erythropoietin, and glycolytic enzymes in the growth plate of cKO mice were detected by quantitative RT-PCR. Immunohistochemistry revealed an increased HIF-1α protein level in the hypertrophic chondrocytes of cKO mice. Infection of chondrocytes isolated from Phd2 floxed mice with adenoviral Cre resulted in similar gene expression patterns as observed in the cKO growth plate chondrocytes. Our findings indicate that Phd2 suppresses endochondral bone formation, in part, via HIF-dependent mechanisms in mice.

Oxygen Tension Directs Chondrogenic Differentiation of Myelo-Monocytic Progenitors During Endochondral Bone Formation

2007 ◽  
Vol 13 (8) ◽  
pp. 2011-2019 ◽  
Author(s):  
Jessica Shafer ◽  
Alan R. Davis ◽  
Francis H. Gannon ◽  
Christine M. Fouletier-Dilling ◽  
Zawaunyka Lazard ◽  
...  
Keyword(s):  
Bone Formation ◽  
Oxygen Tension ◽  
Chondrogenic Differentiation ◽  
Endochondral Bone Formation ◽  
Endochondral Bone
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