scholarly journals Antxr1, Which is a Target of Runx2, Regulates Chondrocyte Proliferation and Apoptosis

2020 ◽  
Vol 21 (7) ◽  
pp. 2425 ◽  
Author(s):  
Qing Jiang ◽  
Xin Qin ◽  
Carolina Andrea Yoshida ◽  
Hisato Komori ◽  
Kei Yamana ◽  
...  
Keyword(s):  
Growth Retardation ◽  
Endochondral Ossification ◽  
Target Genes ◽  
Skeletal Development ◽  
Chondrocyte Apoptosis ◽  
Wild Type ◽  
Chondrocyte Proliferation ◽  
Matrix Mineralization ◽  
Chondrocyte Maturation ◽  
Proliferation And Apoptosis

Antxr1/Tem8 is highly expressed in tumor endothelial cells and is a receptor for anthrax toxin. Mutation of Antxr1 causes GAPO syndrome, which is characterized by growth retardation, alopecia, pseudo-anodontia, and optic atrophy. However, the mechanism underlying the growth retardation remains to be clarified. Runx2 is essential for osteoblast differentiation and chondrocyte maturation and regulates chondrocyte proliferation through Ihh induction. In the search of Runx2 target genes in chondrocytes, we found that Antxr1 expression is upregulated by Runx2. Antxr1 was highly expressed in cartilaginous tissues and was directly regulated by Runx2. In skeletal development, the process of endochondral ossification proceeded similarly in wild-type and Antxr1–/– mice. However, the limbs of Antxr1–/– mice were shorter than those of wild-type mice from embryonic day 16.5 due to the reduced chondrocyte proliferation. Chondrocyte-specific Antxr1 transgenic mice exhibited shortened limbs, although the process of endochondral ossification proceeded as in wild-type mice. BrdU-uptake and apoptosis were both increased in chondrocytes, and the apoptosis-high regions were mineralized. These findings indicated that Antxr1, of which the expression is regulated by Runx2, plays an important role in chondrocyte proliferation and that overexpression of Antxr1 causes chondrocyte apoptosis accompanied by matrix mineralization.

scholarly journals Skeletal Malformations Caused by Overexpression of Cbfa1 or Its Dominant Negative Form in Chondrocytes

2001 ◽  
Vol 153 (1) ◽  
pp. 87-100 ◽  
Author(s):  
Chisato Ueta ◽  
Masahiro Iwamoto ◽  
Naoko Kanatani ◽  
Carolina Yoshida ◽  
Yang Liu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Endochondral Ossification ◽  
Skeletal Development ◽  
Type Ii Collagen ◽  
Dominant Negative ◽  
Chondrocyte Maturation ◽  
Skeletal Malformations ◽  
Dominant Negative Form ◽  
Cellular Phenotypes

During skeletogenesis, cartilage develops to either permanent cartilage that persists through life or transient cartilage that is eventually replaced by bone. However, the mechanism by which cartilage phenotype is specified remains unclarified. Core binding factor α1 (Cbfa1) is an essential transcription factor for osteoblast differentiation and bone formation and has the ability to stimulate chondrocyte maturation in vitro. To understand the roles of Cbfa1 in chondrocytes during skeletal development, we generated transgenic mice that overexpress Cbfa1 or a dominant negative (DN)-Cbfa1 in chondrocytes under the control of a type II collagen promoter/enhancer. Both types of transgenic mice displayed dwarfism and skeletal malformations, which, however, resulted from opposite cellular phenotypes. Cbfa1 overexpression caused acceleration of endochondral ossification due to precocious chondrocyte maturation, whereas overexpression of DN-Cbfa1 suppressed maturation and delayed endochondral ossification. In addition, Cbfa1 transgenic mice failed to form most of their joints and permanent cartilage entered the endochondral pathway, whereas most chondrocytes in DN-Cbfa1 transgenic mice retained a marker for permanent cartilage. These data show that temporally and spatially regulated expression of Cbfa1 in chondrocytes is required for skeletogenesis, including formation of joints, permanent cartilages, and endochondral bones.

scholarly journals Deletion at an 1q24 locus reveals a critical role of long noncoding RNA DNM3OS in skeletal development

2020 ◽  
Author(s):  
Ting-ting Yu ◽  
Qiu-fan Xu ◽  
Hui-jie Huang ◽  
Sarah Dugan ◽  
Lei Shao ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Endochondral Ossification ◽  
Bone Growth ◽  
Skeletal Development ◽  
Critical Role ◽  
Chondrocyte Proliferation ◽  
Complex Processes ◽  
Opposite Strand ◽  
Non Coding Rnas

Abstract Background: Skeletal development and maintenance are complex processes known to be coordinated by multiple genetic and epigenetic signaling pathways. However, the role of long non-coding RNAs (lncRNAs), a class of crucial epigenetic regulatory molecules, has been under explored in skeletal biology. Results: Here we report a young patient with short stature, hypothalamic dysfunction and mild macrocephaly, who carries a maternally inherited 690kb deletion at Chr.1q24.2 encompassing a noncoding RNA gene, DNM3OS, embedded on the opposite strand in an intron of the DYNAMIN 3 (DNM3)gene. We show that lncRNA DNM3OS sustains the proliferation of chondrocytes independent of two co-cistronic microRNAs miR-199a and miR-214. We further show that nerve growth factor (NGF), a known factor of chondrocyte growth, is a key target of DNM3OS-mediated control of chondrocyte proliferation.Conclusion: This work demonstrates that DNM3OS is essential for preventing premature differentiation of chondrocytes required for bone growth through endochondral ossification.

scholarly journals Deletion at an 1q24 locus reveals a critical role of long noncoding RNA DNM3OS in skeletal development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ting-ting Yu ◽  
Qiu-fan Xu ◽  
Si-Yang Li ◽  
Hui-jie Huang ◽  
Sarah Dugan ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Endochondral Ossification ◽  
Bone Growth ◽  
Skeletal Development ◽  
Critical Role ◽  
Chondrocyte Proliferation ◽  
Complex Processes ◽  
Opposite Strand ◽  
Non Coding Rnas

Abstract Background Skeletal development and maintenance are complex processes known to be coordinated by multiple genetic and epigenetic signaling pathways. However, the role of long non-coding RNAs (lncRNAs), a class of crucial epigenetic regulatory molecules, has been under explored in skeletal biology. Results Here we report a young patient with short stature, hypothalamic dysfunction and mild macrocephaly, who carries a maternally inherited 690 kb deletion at Chr.1q24.2 encompassing a noncoding RNA gene, DNM3OS, embedded on the opposite strand in an intron of the DYNAMIN 3 (DNM3) gene. We show that lncRNA DNM3OS sustains the proliferation of chondrocytes independent of two co-cistronic microRNAs miR-199a and miR-214. We further show that nerve growth factor (NGF), a known factor of chondrocyte growth, is a key target of DNM3OS-mediated control of chondrocyte proliferation. Conclusions This work demonstrates that DNM3OS is essential for preventing premature differentiation of chondrocytes required for bone growth through endochondral ossification.

scholarly journals Glucocorticoid Receptor Phosphorylation Differentially Affects Target Gene Expression

2008 ◽  
Vol 22 (8) ◽  
pp. 1754-1766 ◽  
Author(s):  
Weiwei Chen ◽  
Thoa Dang ◽  
Raymond D. Blind ◽  
Zhen Wang ◽  
Claudio N. Cavasotto ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Target Genes ◽  
Divalent Cations ◽  
Phosphorylation Site ◽  
Transcriptional Response ◽  
Receptor Occupancy ◽  
Wild Type ◽  
Interacting Protein

Abstract The glucocorticoid receptor (GR) is phosphorylated at multiple sites within its N terminus (S203, S211, S226), yet the role of phosphorylation in receptor function is not understood. Using a range of agonists and GR phosphorylation site-specific antibodies, we demonstrated that GR transcriptional activation is greatest when the relative phosphorylation of S211 exceeds that of S226. Consistent with this finding, a replacement of S226 with an alanine enhances GR transcriptional response. Using a battery of compounds that perturb different signaling pathways, we found that BAPTA-AM, a chelator of intracellular divalent cations, and curcumin, a natural product with antiinflammatory properties, reduced hormone-dependent phosphorylation at S211. This change in GR phosphorylation was associated with its decreased nuclear retention and transcriptional activation. Molecular modeling suggests that GR S211 phosphorylation promotes a conformational change, which exposes a novel surface potentially facilitating cofactor interaction. Indeed, S211 phosphorylation enhances GR interaction with MED14 (vitamin D receptor interacting protein 150). Interestingly, in U2OS cells expressing a nonphosphorylated GR mutant S211A, the expression of IGF-binding protein 1 and interferon regulatory factor 8, both MED14-dependent GR target genes, was reduced relative to cells expressing wild-type receptor across a broad range of hormone concentrations. In contrast, the induction of glucocorticoid-induced leucine zipper, a MED14-independent GR target, was similar in S211A- and wild-type GR-expressing cells at high hormone levels, but was reduced in S211A cells at low hormone concentrations, suggesting a link between GR phosphorylation, MED14 involvement, and receptor occupancy. Phosphorylation also affected the magnitude of repression by GR in a gene-selective manner. Thus, GR phosphorylation at S211 and S226 determines GR transcriptional response by modifying cofactor interaction. Furthermore, the effect of GR S211 phosphorylation is gene specific and, in some cases, dependent upon the amount of activated receptor.

scholarly journals Pathogenic role of Fgf23 in Dmp1-null mice

2008 ◽  
Vol 295 (2) ◽  
pp. E254-E261 ◽  
Author(s):  
Shiguang Liu ◽  
Jianping Zhou ◽  
Wen Tang ◽  
Rochelle Menard ◽  
Jian Q. Feng ◽  
...  
Keyword(s):  
Growth Retardation ◽  
Matrix Protein ◽  
Serum Levels ◽  
Serum Phosphate ◽  
Hypophosphatemic Rickets ◽  
Null Mouse ◽  
Matrix Mineralization ◽  
Severe Growth ◽  
Inactivating Mutations

Autosomal recessive hypophosphatemic rickets (ARHR), which is characterized by renal phosphate wasting, aberrant regulation of 1α-hydroxylase activity, and rickets/osteomalacia, is caused by inactivating mutations of dentin matrix protein 1 ( DMP1). ARHR resembles autosomal dominant hypophosphatemic rickets (ADHR) and X-linked hypophosphatemia (XLH), hereditary disorders respectively caused by cleavage-resistant mutations of the phosphaturic factor FGF23 and inactivating mutations of PHEX that lead to increased production of FGF23 by osteocytes in bone. Circulating levels of FGF23 are increased in ARHR and its Dmp1-null mouse homologue. To determine the causal role of FGF23 in ARHR, we transferred Fgf23 deficient/enhanced green fluorescent protein (eGFP) reporter mice onto Dmp1-null mice to create mice lacking both Fgf23 and Dmp1. Dmp1−/− mice displayed decreased serum phosphate concentrations, inappropriately normal 1,25(OH)2D levels, severe rickets, and a diffuse form of osteomalacia in association with elevated Fgf23 serum levels and expression in osteocytes. In contrast, Fgf23−/− mice had undetectable serum Fgf23 and elevated serum phosphate and 1,25(OH)2D levels along with severe growth retardation and focal form of osteomalacia. In combined Dmp1−/−/Fgf23−/−, circulating Fgf23 levels were also undetectable, and the serum levels of phosphate and 1,25(OH)2D levels were identical to Fgf23−/− mice. Rickets and diffuse osteomalacia in Dmp1-null mice were transformed to severe growth retardation and focal osteomalacia characteristic of Fgf23-null mice. These data suggest that the regulation of extracellular matrix mineralization by DMP1 is coupled to renal phosphate handling and vitamin D metabolism through a DMP1-dependent regulation of FGF23 production by osteocytes.

A novel PAX5-ELN fusion protein identified in B-cell acute lymphoblastic leukemia acts as a dominant negative on wild-type PAX5

Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3417-3423 ◽  
Author(s):  
Marina Bousquet ◽  
Cyril Broccardo ◽  
Cathy Quelen ◽  
Fabienne Meggetto ◽  
Emilienne Kuhlein ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Target Genes ◽  
Lymphoblastic Leukemia ◽  
Quantitative Polymerase Chain Reaction ◽  
Dominant Negative ◽  
Leukemic Cells ◽  
Dominant Negative Effect ◽  
Wild Type ◽  
Cell Acute Lymphoblastic Leukemia

Abstract We report a novel t(7;9)(q11;p13) translocation in 2 patients with B-cell acute lymphoblastic leukemia (B-ALL). By fluorescent in situ hybridization and 3′ rapid amplification of cDNA ends, we showed that the paired box domain of PAX5 was fused with the elastin (ELN) gene. After cloning the full-length cDNA of the chimeric gene, confocal microscopy of transfected NIH3T3 cells and Burkitt lymphoma cells (DG75) demonstrated that PAX5-ELN was localized in the nucleus. Chromatin immunoprecipitation clearly indicated that PAX5-ELN retained the capability to bind CD19 and BLK promoter sequences. To analyze the functions of the chimeric protein, HeLa cells were cotransfected with a luc-CD19 construct, pcDNA3-PAX5, and with increasing amounts of pcDNA3-PAX5-ELN. Thus, in vitro, PAX5-ELN was able to block CD19 transcription. Furthermore, real-time quantitative polymerase chain reaction (RQ-PCR) experiments showed that PAX5-ELN was able to affect the transcription of endogenous PAX5 target genes. Since PAX5 is essential for B-cell differentiation, this translocation may account for the blockage of leukemic cells at the pre–B-cell stage. The mechanism involved in this process appears to be, at least in part, through a dominant-negative effect of PAX5-ELN on the wild-type PAX5 in a setting ofPAX5 haploinsufficiency.

scholarly journals Evaluating the Influence of a G-Quadruplex Prone Sequence on the Transactivation Potential by Wild-Type and/or Mutant P53 Family Proteins through a Yeast-Based Functional Assay

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 277
Author(s):  
Paola Monti ◽  
Vaclav Brazda ◽  
Natália Bohálová ◽  
Otília Porubiaková ◽  
Paola Menichini ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Relative Activity ◽  
Gene Organization ◽  
Functional Assay ◽  
Wild Type ◽  
P53 Family ◽  
Transactivation Potential ◽  
G Quadruplex

P53, P63, and P73 proteins belong to the P53 family of transcription factors, sharing a common gene organization that, from the P1 and P2 promoters, produces two groups of mRNAs encoding proteins with different N-terminal regions; moreover, alternative splicing events at C-terminus further contribute to the generation of multiple isoforms. P53 family proteins can influence a plethora of cellular pathways mainly through the direct binding to specific DNA sequences known as response elements (REs), and the transactivation of the corresponding target genes. However, the transcriptional activation by P53 family members can be regulated at multiple levels, including the DNA topology at responsive promoters. Here, by using a yeast-based functional assay, we evaluated the influence that a G-quadruplex (G4) prone sequence adjacent to the p53 RE derived from the apoptotic PUMA target gene can exert on the transactivation potential of full-length and N-terminal truncated P53 family α isoforms (wild-type and mutant). Our results show that the presence of a G4 prone sequence upstream or downstream of the P53 RE leads to significant changes in the relative activity of P53 family proteins, emphasizing the potential role of structural DNA features as modifiers of P53 family functions at target promoter sites.

scholarly journals Crosstalk between p53 and TGF-β Signalling

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Rebecca Elston ◽  
Gareth J. Inman
Keyword(s):  
Transcriptional Activation ◽  
Cancer Biology ◽  
Target Genes ◽  
Tumour Progression ◽  
Signal Transduction Pathway ◽  
Mirna Biogenesis ◽  
Mutant P53 ◽  
Wild Type ◽  
P53 Family ◽  
Wild Type P53

Wild-type p53 and TGF-β are key tumour suppressors which regulate an array of cellular responses. TGF-β signals in part via the Smad signal transduction pathway. Wild-type p53 and Smads physically interact and coordinately induce transcription of a number of key tumour suppressive genes. Conversely mutant p53 generally subverts tumour suppressive TGF-β responses, diminishing transcriptional activation of key TGF-β target genes. Mutant p53 can also interact with Smads and this enables complex formation with the p53 family member p63 and blocks p63-mediated activation of metastasis suppressing genes to promote tumour progression. p53 and Smad function may also overlap during miRNA biogenesis as they can interact with the same components of the Drosha miRNA processing complex to promote maturation of specific subsets of miRNAs. This paper investigates the crosstalk between p53 and TGF-β signalling and the potential roles this plays in cancer biology.

scholarly journals Deubiquitinating Enzyme USP8 Is Essential for Skeletogenesis by Regulating Wnt Signaling

2021 ◽  
Vol 22 (19) ◽  
pp. 10289
Author(s):  
Sachin Chaugule ◽  
Jung-Min Kim ◽  
Yeon-Suk Yang ◽  
Klaus-Peter Knobeloch ◽  
Xi He ◽  
...  
Keyword(s):  
Stem Cells ◽  
Skeletal Development ◽  
Fine Tuning ◽  
Osteogenic Potential ◽  
Deubiquitinating Enzyme ◽  
Renal Capsule ◽  
Wild Type ◽  
Lysosomal Degradation ◽  
Specific Protease ◽  
Ubiquitin Specific Protease

Disturbance in a differentiation program of skeletal stem cells leads to indecorous skeletogenesis. Growing evidence suggests that a fine-tuning of ubiquitin-mediated protein degradation is crucial for skeletal stem cells to maintain their stemness and osteogenic potential. Here, we demonstrate that the deubiquitinating enzyme (DUB) ubiquitin-specific protease 8 (USP8) stabilizes the Wnt receptor frizzled 5 (FZD5) by preventing its lysosomal degradation. This pathway is essential for Wnt/β-catenin signaling and the differentiation of osteoprogenitors to mature osteoblasts. Accordingly, deletion of USP8 in osteoprogenitors (Usp8Osx) resulted in a near-complete blockade in skeletal mineralization, similar to that seen in mice with defective Wnt/β-catenin signaling. Likewise, transplanting USP8-deficient osteoprogenitors under the renal capsule in wild-type secondary hosts did not to induce bone formation. Collectively, this study unveils an essential role for the DUB USP8 in Wnt/β-catenin signaling in osteoprogenitors and osteogenesis during skeletal development.

Sign in / Sign up

Export Citation Format

Share Document