scholarly journals BRD4 promotes heterotopic ossification through upregulation of LncRNA MANCR

2021 ◽  
Vol 10 (10) ◽  
pp. 668-676
Author(s):  
Lei Liu ◽  
ZiHao Li ◽  
Siwen Chen ◽  
Haowen Cui ◽  
Xiang Li ◽  
...  

Aims Acquired heterotopic ossification (HO) is a debilitating disease characterized by abnormal extraskeletal bone formation within soft-tissues after injury. The exact pathogenesis of HO remains unknown. It was reported that BRD4 may contribute to osteoblastic differentiation. The current study aims to determine the role of BRD4 in the pathogenesis of HO and whether it could be a potential target for HO therapy. Methods Achilles tendon puncture (ATP) mouse model was performed on ten-week-old male C57BL/6J mice. One week after ATP procedure, the mice were given different treatments (e.g. JQ1, shMancr). Achilles tendon samples were collected five weeks after treatment for RNA-seq and real-time quantitative polymerase chain reaction (RT-qPCR) analysis; the legs were removed for micro-CT imaging and subsequent histology. Human bone marrow mesenchymal stem cells (hBMSCs) were isolated and purified bone marrow collected during surgeries by using density gradient centrifugation. After a series of interventions such as knockdown or overexpressing BRD4, Alizarin red staining, RT-qPCR, and Western Blot (Runx2, alkaline phosphatase (ALP), Osx) were performed on hBMSCs. Results Overexpression of BRD4 enhanced while inhibition of Brd4 suppressed the osteogenic differentiation of hBMSCs in vitro. Overexpression of Brd4 increased the expression of mitotically associated long non-coding RNA (Mancr). Downregulation of Mancr suppressed the osteoinductive effect of BRD4. In vivo, inhibition of BRD4 by JQ1 significantly attenuated pathological bone formation in the ATP model (p = 0.001). Conclusion BRD4 was found to be upregulated in HO and Brd4-Mancr-Runx2 signalling was involved in the modulation of new bone formation in HO. Cite this article: Bone Joint Res 2021;10(10):668–676.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjing Jin ◽  
Xianfeng Lin ◽  
Haihua Pan ◽  
Chenchen Zhao ◽  
Pengcheng Qiu ◽  
...  

AbstractOsteoclasts (OCs), the only cells capable of remodeling bone, can demineralize calcium minerals biologically. Naive OCs have limitations for the removal of ectopic calcification, such as in heterotopic ossification (HO), due to their restricted activity, migration and poor adhesion to sites of ectopic calcification. HO is the formation of pathological mature bone within extraskeletal soft tissues, and there are currently no reliable methods for removing these unexpected calcified plaques. In the present study, we develop a chemical approach to modify OCs with tetracycline (TC) to produce engineered OCs (TC-OCs) with an enhanced capacity for targeting and adhering to ectopic calcified tissue due to a broad affinity for calcium minerals. Unlike naive OCs, TC-OCs are able to effectively remove HO both in vitro and in vivo. This achievement indicates that HO can be reversed using modified OCs and holds promise for engineering cells as “living treatment agents” for cell therapy.


2006 ◽  
Vol 6 (5) ◽  
pp. 74S
Author(s):  
Tara Aghaloo ◽  
Xinquan Jiang ◽  
Xinli Zhang ◽  
Zhang Zhiyuang ◽  
Jeffrey C. Wang ◽  
...  

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1409-1409
Author(s):  
Zhuo Wang ◽  
Junghun Jung ◽  
Magdalena Kucia ◽  
Junhui Song ◽  
Yusuke Shiozawa ◽  
...  

Abstract We previously developed an in vivo prospective assay for identification of non-cultured cells with MSC potential. Using this assay we identified a population of cells that were slowly cycling and of low density that were capable of multilineage differentiation both in vitro and in vivo (Z. Wang et al, Stem Cells. 2006 24(6):1573). Further characterization of these cells suggested that they resemble a homogenous population of rare Lin−/Sca-1+/CD45− cells that have the morphology and express several markers of undifferentiated embryonic-like stem cells. In vitro the Lin−/Sca-1+/CD45− cells may differentiate into cells from all three germ-layers (M. Kucia et al, Leukemia. 2007 21(2):297). To determine the in vivo fate of this population, we transplanted 500 or 5,000 Lin−/Sca-1+/CD45− cells from a GFP mouse into SCID mice in each group (n=3) immediately after cell sorting to evaluate tissue generation in vivo. At 4 weeks the regenerative potential of these populations was evaluated by micro-CT and histology, and cells were tracked by gross examination of the harvested tissues by fluorescent microscopy. The results showed that a large number of GFP+ cells are located in the implants, indicating that the transplanted cells maintain the ability to contribute to the generation of new tissue. Bone-like tissue was observed in the Lin−/Sca-1+/CD45− group with as low as 500-cells/implant, while 5,000 Lin−/Sca-1+/CD45− cells generated significantly larger mineralized tissue volume, which was confirmed by micro-CT. Lin−/Sca-1+/CD45+ cell only implantation did not form any mineralized tissue, however, while mixed with 2x106 whole bone morrow cells, positive mineralized tissue occurred. Whole bone marrow mixture also improve bone formation in Lin−/Sca-1+/CD45− cell implants compared the actual bone volumes measured by micro-CT. This study demonstrates that non-cultured BM-derived Lin−/Sca-1+/CD45− cells exhibit the capacity to form bone in vivo with as low as 500 cells/implant. Whole bone marrow mixtures can enhance the bone formation, presumably through the interaction of other populations cells. Based on these findings, it is proposed that non-cultured BM-derived Lin−/Sca-1+/CD45− cells are enriched osteogenic cells that can be applied to bone regeneration in vivo.


2015 ◽  
Vol 13 ◽  
pp. 254-265 ◽  
Author(s):  
Wanxun Yang ◽  
Sanne K. Both ◽  
Gerjo J.V.M. van Osch ◽  
Yining Wang ◽  
John A. Jansen ◽  
...  

Bioceramics ◽  
1999 ◽  
Author(s):  
M. Lamghari ◽  
S. Berland ◽  
A. Laurent ◽  
H. Huet ◽  
M.J. Almeida ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dan Zhang ◽  
Kim De Veirman ◽  
Rong Fan ◽  
Qiang Jian ◽  
Yuchen Zhang ◽  
...  

Abstract Background Bone destruction is a hallmark of multiple myeloma (MM). It has been reported that proteasome inhibitors (PIs) can reduce bone resorption and increase bone formation in MM patients, but the underlying mechanisms remain unclear. Methods Mesenchymal stem cells (MSCs) were treated with various doses of PIs, and the effects of bortezomib or carfilzomib on endoplasmic reticulum (ER) stress signaling pathways were analyzed by western blotting and real-time PCR. Alizarin red S (ARS) and alkaline phosphatase (ALP) staining were used to determine the osteogenic differentiation in vitro. Specific inhibitors targeting different ER stress signaling and a Tet-on inducible overexpressing system were used to validate the roles of key ER stress components in regulating osteogenic differentiation of MSCs. Chromatin immunoprecipitation (ChIP) assay was used to evaluate transcription factor-promoter interaction. MicroCT was applied to measure the microarchitecture of bone in model mice in vivo. Results We found that both PERK-ATF4 and IRE1α-XBP1s ER stress branches are activated during PI-induced osteogenic differentiation. Inhibition of ATF4 or XBP1s signaling can significantly impair PI-induced osteogenic differentiation. Furthermore, we demonstrated that XBP1s can transcriptionally upregulate ATF4 expression and overexpressing XBP1s can induce the expression of ATF4 and other osteogenic differentiation-related genes and therefore drive osteoblast differentiation. MicroCT analysis further demonstrated that inhibition of XBP1s can strikingly abolish bortezomib-induced bone formation in mouse. Conclusions These results demonstrated that XBP1s is a master regulator of PI-induced osteoblast differentiation. Activation of IRE1α-XBP1s ER stress signaling can promote osteogenesis, thus providing a novel strategy for the treatment of myeloma bone disease.


2001 ◽  
Vol 168 (1) ◽  
pp. 131-139 ◽  
Author(s):  
S Keila ◽  
A Kelner ◽  
M Weinreb

Prostaglandin E(2) (PGE(2)) has been shown to exert a bone anabolic effect in young and adult rats. In this study we tested whether it possesses a similar effect on bone formation and bone mass in aging rats. Fifteen-month-old rats were injected daily with either PGE(2) at 5 mg/kg or vehicle for 14 days. PGE(2) treatment stimulated the rate of cancellous bone formation (a approximately 5.5-fold increase in bone formation rate), measured by the incorporation of calcein into bone-forming surfaces at the tibial proximal metaphysis. This effect resulted in increased cancellous bone area (+54%) at the same site. Since PGE(2) treatment resulted in a much higher proportion of bone surface undergoing bone formation and thus lined with osteoblasts, we tested the hypothesis that PGE(2) stimulates osteoblast differentiation from bone marrow precursor cells both in vivo and in vitro. We found that ex vivo cultures of bone marrow stromal cells from rats injected for 2 weeks with PGE(2) at 5 mg/kg per day yielded more ( approximately 4-fold) mineralized nodules and exhibited a greater (by 30-40%) alkaline phosphatase activity compared with cultures from vehicle-injected rats, attesting to a stimulation of osteoblastic differentiation by PGE(2). We also compared the osteogenic capacity of bone marrow from aging (15-month-old) versus young (5-week-old) rats and its regulation by PGE(2) in vitro. Bone marrow stromal cell cultures from aging rats exhibited a greatly diminished osteogenic capacity, reflected in reduced nodule formation ( approximately 6% of young animals) and lower alkaline phosphatase activity ( approximately 60% of young animals). However, these parameters could be stimulated in both groups of animals by incubation with 10-100 nM PGE(2). The magnitude of this stimulation was greater in cultures from aging rats (+550% vs +70% in nodule formation of aging compared with young rats). In conclusion, we demonstrate here that PGE(2) exerts a bone anabolic effect in aging rats, similar to the effect we and others have reported in young, growing rats. The PGE(2)-stimulated bone formation, which augments bone mass, most likely results from recruitment of osteoblasts from their bone marrow stromal precursors.


2020 ◽  
Author(s):  
Nafiseh Baheiraei ◽  
Hossein Eyni ◽  
Bita bakhshi ◽  
Raziyeh Najafloo

Abstract Background: Bioactive glasses (BGs) have attracted added attention in the structure of the scaffolds for bone repair applications. Different metal ions could be doped in BGs to induce specific biological responses. Among these ions, strontium (Sr) is considered as an effective and safe doping element with promising effects on bone formation and regeneration.Methods: In this experiment, we evaluated the antibacterial activities of the gelatin-BG (Gel-BG) and Gel-BG/Sr scaffolds in vitro. The osteogenic properties of the prepared scaffolds were also assessed in rabbit calvarial bone defects for 12 weeks. Alizarin Red, Hematoxylin & Eosin (H&E) and Masson’s Trichrome staining were performed to assess bone regeneration and the obtained results were compared with those without Sr. Also, histomorphometric data were obtained to evaluate the new bone, residual graft, and connective tissue.Results: Both scaffolds showed in vivo bone formation during 12 weeks with the newly formed bone area in Gel-BG/Sr scaffold was higher than that in Gel-BG scaffolds after the whole period. Based on the histological results, Gel-BG/Sr exhibited acceleration of early-stage bone formation in vivo. The results of antibacterial investigation showed that although both Gel-BG/Sr and Gel-BG effectively inhibited the growth of Escherichia coli (E. coli) but, only Gel-BG/Sr structure could lead to a 3 log reduction in Staphylococcus aureus (S. aureus). Conclusions: Our results confirmed that Sr doped BG is a favorable candidate for bone tissue engineering with superior antibacterial activity and bone regeneration capacity compared with similar counterparts having no Sr ion.


2020 ◽  
Author(s):  
Mallika Ghosh ◽  
Ivo Kalajzic ◽  
Hector Leonardo Aguila ◽  
Linda H Shapiro

AbstractIn vertebrates, bone formation is dynamically controlled by the activity of two specialized cell types: the bone-generating osteoblasts and bone-degrading osteoclasts. Osteoblasts produce the soluble receptor activator of NFκB ligand (RANKL) that binds to its receptor RANK on the surface of osteoclast precursor cells to promote osteoclastogenesis, a process that involves cell-cell fusion and assembly of molecular machinery to ultimately degrade the bone. CD13 is a transmembrane aminopeptidase that is highly expressed in cells of myeloid lineage has been shown to regulate dynamin-dependent receptor endocytosis and recycling and is a necessary component of actin cytoskeletal organization. In the present study, we show that CD13-deficient mice display a normal distribution of osteoclast progenitor populations in the bone marrow, but present a low bone density phenotype. Further, the endosteal bone formation rate is similar between genotypes, indicating a defect in osteoclast-specific function in vivo. Loss of CD13 led to exaggerated in vitro osteoclastogenesis as indicated by significantly enhanced fusion of bone marrow-derived multinucleated osteoclasts in the presence of M-CSF and RANKL, resulting in abnormally large cells with remarkably high numbers of nuclei with a concomitant increase in bone resorption activity. Similarly, we also observed increased formation of multinucleated giant cells (MGC) in CD13KO bone marrow progenitor cells stimulated with IL-4 and IL-13, suggesting that CD13 may regulate cell-cell fusion events via a common pathway, independent of RANKL signaling. Mechanistically, while expression levels of the fusion-regulatory proteins dynamin and DC-STAMP are normally downregulated as fusion progresses in fusion-competent mononucleated progenitor cells, in the absence of CD13 they are uniformly sustained at high levels, even in mature multi-nucleated osteoclasts. Taken together, we conclude that CD13 may regulate cell-cell fusion by controlling expression and localization of key fusion proteins that are critical for both osteoclast and MGC fusion.


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