scholarly journals TAZ is required for chondrogenesis and skeletal development

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yang Li ◽  
Shuting Yang ◽  
Ling Qin ◽  
Shuying Yang

AbstractChondrogenesis is a major contributor to skeletal development and maintenance, as well as bone repair. Transcriptional coactivator with PDZ-binding motif (TAZ) is a key regulator of osteogenesis and adipogenesis, but how TAZ regulates chondrogenesis and skeletal development remains undefined. Here, we found that TAZ expression is gradually increased during chondrogenic differentiation. Deletion of TAZ in chondrocyte lineage impaired articular and growth plate, as well as the bone development in TAZ-deficient mice. Consistently, loss of TAZ impaired fracture healing. Mechanistically, we found that ectopic expression of TAZ markedly promoted chondroprogenitor proliferation, while deletion of TAZ impaired chondrocyte proliferation and differentiation. TAZ associated with Sox5 to regulate the expression and stability of Sox5 and downstream chondrocyte marker genes’ expression. In addition, overexpression of TAZ enhanced Col10a1 expression and promoted chondrocyte maturation, which was blocked by deletion of TAZ. Overall, our findings demonstrated that TAZ is required for skeletal development and joint maintenance that provided new insights into therapeutic strategies for fracture healing, heterotopic ossification, osteoarthritis, and other bone diseases.

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3468
Author(s):  
Anqi Li ◽  
Xiaotong Su ◽  
Yuan Tian ◽  
Guibing Song ◽  
Linsen Zan ◽  
...  

Actin Alpha Cardiac Muscle 1 (ACTC1) gene is a differentially expressed gene screened through the co-culture system of myoblasts-preadipocytes. In order to study the role of this gene in the process of proliferation and differentiation of bovine myoblasts and preadipocytes, the methods of the knockdown, overexpression, and ectopic expression of ACTC1 were used in this study. After ACTC1 knockdown in bovine myoblasts and inducing differentiation, the sizes and numbers of myotube formation were significantly reduced compared to the control group, and myogenic marker genes—MYOD1, MYOG, MYH3, MRF4, MYF5, CKM and MEF2A—were significantly decreased (p < 0.05, p < 0.01) at both the mRNA and protein levels of myoblasts at different differentiation stages (D0, D2, D4, D6 and D8). Conversely, ACTC1 overexpression induced the inverse result. After ectopic expression of ACTC1 in bovine preadipocytes and induced differentiation, the number and size of lipid droplets were significantly higher than those of the control group, and the expression of adipogenic marker genes—FABP4, SCD1, PPARγ and FASN—were significantly increased (p < 0.05, p < 0.01) at the mRNA and protein levels of preadipocytes at different differentiation stages. Flow cytometry results showed that both the knockdown and overexpression of ACTC1 inhibited the normal cell cycle of myoblasts; however, ectopic expression of ACTC1 in adipocytes induced no significant cell cycle changes. This study is the first to explore the role of ACTC1 in bovine myogenesis and lipogenesis and demonstrates that ACTC1 promotes the differentiation of bovine myoblasts and preadipocytes, affecting the proliferation of myoblasts.


2014 ◽  
Vol 52 (3) ◽  
pp. R179-R197 ◽  
Author(s):  
Beatriz Gámez ◽  
Edgardo Rodriguez-Carballo ◽  
Francesc Ventura

MicroRNAs (miRNAs) have become integral nodes of post-transcriptional control of genes that confer cellular identity and regulate differentiation. Cell-specific signaling and transcriptional regulation in skeletal biology are extremely dynamic processes that are highly reliant on dose-dependent responses. As such, skeletal cell-determining genes are ideal targets for quantitative regulation by miRNAs. So far, large amounts of evidence have revealed a characteristic temporal miRNA signature in skeletal cell differentiation and confirmed the essential roles that numerous miRNAs play in bone development and homeostasis. In addition, microarray expression data have provided evidence for their role in several skeletal pathologies. Mouse models in which their expression is altered have provided evidence of causal links between miRNAs and bone abnormalities. Thus, a detailed understanding of the function of miRNAs and their tight relationship with bone diseases would constitute a powerful tool for early diagnosis and future therapeutic approaches.


2005 ◽  
Vol 76 (4) ◽  
pp. 299-306 ◽  
Author(s):  
G. Li ◽  
J. R. Bunn ◽  
M. T. Mushipe ◽  
Q. He ◽  
X. Chen

2019 ◽  
Author(s):  
Bethany A. Kerr ◽  
Lihong Shi ◽  
Alexander H. Jinnah ◽  
Jeffrey S. Willey ◽  
Donald P. Lennon ◽  
...  

ABSTRACTIdentifying patient mutations driving skeletal development disorders has driven our understanding of bone development. Integrin adhesion deficiency disease is caused by a Kindlin-3 (fermitin family member 3) mutation and its inactivation results in bleeding disorders and osteopenia. In this study, we uncover a role for Kindlin-3 in the differentiation of bone marrow mesenchymal stem cells (BMSCs) down the chondrogenic lineage. Kindlin-3 expression increased with chondrogenic differentiation similar to RUNX2. BMSCs isolated from a Kindlin-3 deficient patient expressed chondrocyte markers including SOX9 under basal conditions, which were further enhanced with chondrogenic differentiation. Rescue of integrin activation by a constitutively activated β3 integrin construct increased adhesion to multiple extracellular matrices and reduced SOX9 expression to basal levels. Growth plates from mice expressing a mutated Kindlin-3 with the integrin binding site ablated demonstrated alterations in chondrocyte maturation similar to that seen with the human Kindlin-3 deficient BMSCs. These findings suggest that Kindlin-3 expression mirrors RUNX2 during chondrogenesis.SUMMARYThis study by Kerr et al. describes a new role for Kindlin-3 in controlling early chondrocyte differentiation from mesenchymal stem cells and later hypertrophic differentiation of chondrocytes.


Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 975
Author(s):  
Kara Corps ◽  
Monica Stanwick ◽  
Juliann Rectenwald ◽  
Andrew Kruggel ◽  
Sarah B. Peters

Transforming growth factor β (TGFβ) signaling plays an important role in skeletal development. We previously demonstrated that the loss of TGFβ receptor II (Tgfbr2) in Osterix-Cre-expressing mesenchyme results in defects in bones and teeth due to reduced proliferation and differentiation in pre-osteoblasts and pre-odontoblasts. These Osterix-Cre;Tgfbr2f/f mice typically die within approximately four weeks for unknown reasons. To investigate the cause of death, we performed extensive pathological analysis on Osterix-Cre- (Cre-), Osterix-Cre+;Tgfbr2f/wt (HET), and Osterix-Cre+;Tgfbr2f/f (CKO) mice. We also crossed Osterix-Cre mice with the ROSA26mTmG reporter line to identify potential off-target Cre expression. The findings recapitulated published skeletal and tooth abnormalities and revealed previously unreported osteochondral dysplasia throughout both the appendicular and axial skeletons in the CKO mice, including the calvaria. Alterations to the nasal area and teeth suggest a potentially reduced capacity to sense and process food, while off-target Cre expression in the gastrointestinal tract may indicate an inability to absorb nutrients. Additionally, altered nasal passages and unexplained changes in diaphragmatic muscle support the possibility of hypoxia. We conclude that these mice likely died due to a combination of breathing difficulties, malnutrition, and starvation resulting primarily from skeletal deformities that decreased their ability to sense, gather, and process food.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Laura Piovani ◽  
Anna Czarkwiani ◽  
Cinzia Ferrario ◽  
Michela Sugni ◽  
Paola Oliveri

Abstract Background Regeneration is the ability to re-grow body parts or tissues after trauma, and it is widespread across metazoans. Cells involved in regeneration can arise from a pool of undifferentiated proliferative cells or be recruited from pre-existing differentiated tissues. Both mechanisms have been described in different phyla; however, the cellular and molecular mechanisms employed by different animals to restore lost tissues as well as the source of cells involved in regeneration remain largely unknown. Echinoderms are a clade of deuterostome invertebrates that show striking larval and adult regenerative abilities in all extant classes. Here, we use the brittle star Amphiura filiformis to investigate the origin and differentiation of cells involved in skeletal regeneration using a combination of microscopy techniques and molecular markers. Results Our ultrastructural analyses at different regenerative stages identify a population of morphologically undifferentiated cells which appear in close contact with the proliferating epithelium of the regenerating aboral coelomic cavity. These cells express skeletogenic marker genes, such as the transcription factor alx1 and the differentiation genes c-lectin and msp130L, and display a gradient of morphological differentiation from the aboral coelomic cavity towards the epidermis. Cells closer to the epidermis, which are in contact with developing spicules, have the morphology of mature skeletal cells (sclerocytes), and express several skeletogenic transcription factors and differentiation genes. Moreover, as regeneration progresses, sclerocytes show a different combinatorial expression of genes in various skeletal elements. Conclusions We hypothesize that sclerocyte precursors originate from the epithelium of the proliferating aboral coelomic cavity. As these cells migrate towards the epidermis, they differentiate and start secreting spicules. Moreover, our study shows that molecular and cellular processes involved in skeletal regeneration resemble those used during skeletal development, hinting at a possible conservation of developmental programmes during adult regeneration. Finally, we highlight that many genes involved in echinoderm skeletogenesis also play a role in vertebrate skeleton formation, suggesting a possible common origin of the deuterostome endoskeleton pathway.


Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 159
Author(s):  
Víctor Santos-Rosales ◽  
Inés Ardao ◽  
Leticia Goimil ◽  
Jose Luis Gomez-Amoza ◽  
Carlos A. García-González

Demand of scaffolds for hard tissue repair increases due to a higher incidence of fractures related to accidents and bone-diseases that are linked to the ageing of the population. Namely, scaffolds loaded with bioactive agents can facilitate the bone repair by favoring the bone integration and avoiding post-grafting complications. Supercritical (sc-)foaming technology emerges as a unique solvent-free approach for the processing of drug-loadenu7d scaffolds at high incorporation yields. In this work, medicated poly(ε-caprolactone) (PCL) scaffolds were prepared by sc-foaming coupled with a leaching process to overcome problems of pore size tuning of the sc-foaming technique. The removal of the solid porogen (BA, ammonium bicarbonate) was carried out by a thermal leaching taking place at 37 °C and in the absence of solvents for the first time. Macroporous scaffolds with dual porosity (50–100 µm and 200–400 µm ranges) were obtained and with a porous structure directly dependent on the porogen content used. The processing of ketoprofen-loaded scaffolds using BA porogen resulted in drug loading yields close to 100% and influenced its release profile from the PCL matrix to a relevant clinical scenario. A novel solvent-free strategy has been set to integrate the incorporation of solid porogens in the sc-foaming of medicated scaffolds.


2005 ◽  
Vol 16 (11) ◽  
pp. 5316-5333 ◽  
Author(s):  
Claudine G. James ◽  
C. Thomas G. Appleton ◽  
Veronica Ulici ◽  
T. Michael Underhill ◽  
Frank Beier

Ordered chondrocyte differentiation and maturation is required for normal skeletal development, but the intracellular pathways regulating this process remain largely unclear. We used Affymetrix microarrays to examine temporal gene expression patterns during chondrogenic differentiation in a mouse micromass culture system. Robust normalization of the data identified 3300 differentially expressed probe sets, which corresponds to 1772, 481, and 249 probe sets exhibiting minimum 2-, 5-, and 10-fold changes over the time period, respectively. GeneOntology annotations for molecular function show changes in the expression of molecules involved in transcriptional regulation and signal transduction among others. The expression of identified markers was confirmed by RT-PCR, and cluster analysis revealed groups of coexpressed transcripts. One gene that was up-regulated at later stages of chondrocyte differentiation was Rgs2. Overexpression of Rgs2 in the chondrogenic cell line ATDC5 resulted in accelerated hypertrophic differentiation, thus providing functional validation of microarray data. Collectively, these analyses provide novel information on the temporal expression of molecules regulating endochondral bone development.


1997 ◽  
Vol 110 (21) ◽  
pp. 2691-2701 ◽  
Author(s):  
N.S. Stott ◽  
C.M. Chuong

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.


2006 ◽  
Vol 26 (8) ◽  
pp. 2947-2954 ◽  
Author(s):  
Wei Gong ◽  
Michael Russell ◽  
Keiko Suzuki ◽  
Karl Riabowol

ABSTRACT ING1 is a type II tumor suppressor that affects cell growth, stress signaling, apoptosis, and DNA repair by altering chromatin structure and regulating transcription. Decreased ING1 expression is seen in several human cancers, and mislocalization has been noted in diverse types of cancer cells. Aberrant targeting may, therefore, functionally inactivate ING1. Bioinformatics analysis identified a sequence between the nuclear localization sequence and plant homeodomain domains of ING1 that closely matched the binding motif of 14-3-3 proteins that target cargo proteins to specific subcellular locales. We find that the widely expressed p33ING1b splicing isoform of ING1 interacts with members of the 14-3-3 family of proteins and that this interaction is regulated by the phosphorylation status of ING1. 14-3-3 binding resulted in significant amounts of p33ING1b protein being tethered in the cytoplasm. As shown previously, ectopic expression of p33ING1b increased levels of the p21Waf1 cyclin-dependent kinase inhibitor upon UV-induced DNA damage. Overexpression of 14-3-3 inhibited the up-regulation of p21Waf1 by p33ING1b, consistent with the idea that mislocalization blocks at least one of ING1's biological activities. These data support the idea that the 14-3-3 proteins play a crucial role in regulating the activity of p33ING1b by directing its subcellular localization.


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