Delta-like 1/fetal antigen 1 (DLK1/FA1) inhibits BMP2-induced osteoblast differentiation by modulating Nf[kappa]b signaling pathway: a novel mechanism for regulation of bone formation

Abstract Background: Many studies have found that circRNA plays a part in osteoblast differentiation. However, its mechanism remains unknown. Methods: High-throughput sequencing was used to identifield the different expression of circRNA during osteogenic dental pulp stem cells (DPSCs) differentiation. Luciferase report analysis and RT-qPCR were used to clarify the expression and regulation relationship among circ-FURIN, miR-125 and SOX11. The heterotopic bone formation experiment was further used to confirm the osteoblast differentiation of DPSC with different expression of circ-FURIN, miR-125 and SOX11. Results: Study indicated that circ-FURIN expression remarkably increased during osteoblast differentiation, yet circ-FURIN knockdown suppressed it. Bioinformatics and luciferase results discovered that miR-125 is the downstream target of circ-FURIN. Furthermore, circ-FURIN upregulation decreased miR-125 expression. MiR-125 upregulation restored the promotion effect of circ-FURIN on osteogenic DPSC differentiation. Luciferase report analysis verified that SOX11 is miR-125 downstream target. miR-125 overexpression suppressed osteogenic DPSC differentiation through targeting SOX11. SOX11 overexpression restored miR-125 inhibitory effect on osteogenic DPSC differentiation. In vivo experiments with heterotopic bone model suggested that circ-FURIN overexpression has crucial function to enhance heterotopic bone formation. Conclusions: In summary, circ-FURIN enhances osteoblast DPSC differentiation via the SOX11 signaling pathway by sponging miR-125. These findings suggest a novel therapeutic target for osteoporosis treatment.

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Myeloma Cells Suppress Osteoblast Differentiation by Secreting a Soluble Wnt Inhibitor, sFRP-2.

Blood ◽

10.1182/blood.v104.11.2356.2356 ◽

2004 ◽

Vol 104 (11) ◽

pp. 2356-2356 ◽

Cited By ~ 2

Author(s):

Takashi Oshima ◽

Masahiro Abe ◽

Jin Asano ◽

Tomoko Hara ◽

Kenichi Kitazoe ◽

...

Keyword(s):

Bone Resorption ◽

Bone Formation ◽

Wnt Signaling ◽

Signaling Pathway ◽

Cell Lines ◽

Osteoblast Differentiation ◽

Wnt Signaling Pathway ◽

Bone Destruction ◽

Nodule Formation ◽

Mrna Levels

Abstract Multiple myeloma (MM), a malignancy of plasma cells, develops in the bone marrow, and generates devastating bone destruction. Along with enhanced bone resorption, clinical evidence has also suggested suppression of bone formation as a contributing factor to the bone loss in MM. In contrast to recent understanding on mechanisms of osteolysis enahnced in MM, little is known about factors responsible for impaired bone formation. A canonical Wingless-type (Wnt) signaling pathway has recently been shown to play a critical role in osteoblast differentiation. Therefore, in the present study, we aimed to clarify mechanisms of suppression of osteoblast differentiation by MM cells with a particular focus on a canonical Wnt signaling pathway. Because several secreted Frizzled related protein (sFRP) and DKK family members are known as soluble Wnt antagonists, we first examined the expression of sFRP-1, 2 and 3 and DKK-1 in MM cell lines including U266, RPMI8226 and ARH77. All cell lines expressed sFRP-2 and sFRP-3 mRNA observed by RT-PCR. However, sFRP-1 was not expressed in any cell line, and Dkk-1 was expressed only in U266 cells at mRNA levels. We next conducted Western blot analyses for these factors and detected only sFRP-2 in immunoprecipitants of conditioned media as well as cell lysates of all these cell lines. However, no other factors were found at protein levels. Furthermore, sFRP-2 mRNA and protein expression was detected in most MM cells from patients with advanced or terminal stages of MM with bone destruction including plasma cell leukemia (3/4 and 8/10, respectively). In order to examine a biological role for sFRP-2, we added recombinant sFRP-2 to MC3T3-E1 cell culture together with BMP-2. Exogenous sFRP-2 partially suppressed alkaline phosphatase activity but almost completely mineralized nodule formation enhanced by BMP-2. Furthermore, sFRP-2 immunodepletion significantly restored mineralized nodule formation in MC3T3-E1 cells suppressed by RPMI8226 and ARH77 CM. These results suggest that sFRP-2 alone is able to suppress osteoblast differentiation induced by BMP-2 and that MM cell-derived sFRP-2 is among predominant factors responsible for defective bone formation in MM. Because MM cell-derived factors such as DKK-1, IGF-BP4 and IL-3 other than sFRP-2 have been implicated as an inhibitor of osteoblast differentiation, sFRP-2 may act alone or in combination with such other factors to potently suppress bone formation in MM. Taken together, MM cells may cause an imbalance of bone turnover with enhanced osteoclastic bone resorption and concomitantly suppressed bone formation, which leads to devastating destruction and a rapid loss of bone.

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Overexpression of PIK3R1 Promotes Bone Formation by Regulating Osteoblast Differentiation and Osteoclast Formation

Computational and Mathematical Methods in Medicine ◽

10.1155/2021/2909454 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Haitao Zhu ◽

Hua Chen ◽

Degang Ding ◽

Shui Wang ◽

Xiaofeng Dai ◽

...

Keyword(s):

Bone Formation ◽

Signaling Pathway ◽

Differentially Expressed Genes ◽

Osteoblast Differentiation ◽

Osteoclast Differentiation ◽

Osteoclast Formation ◽

Differentially Expressed ◽

Estrogen Signaling ◽

Mineral Density

In an effort to bolster our understanding of regulation of bone formation in the context of osteoporosis, we screened out differentially expressed genes in osteoporosis patients with high and low bone mineral density by bioinformatics analysis. PIK3R1 is increasingly being nominated as a pivotal mediator in the differentiation of osteoblasts and osteoclasts that is closely related to bone formation. However, the specific mechanisms underlying the way that PIK3R1 affects bone metabolism are not fully elucidated. We intended to examine the potential mechanism by which PIK3R1 regulates osteoblast differentiation. Enrichment analysis was therefore carried out for differentially expressed genes. We noted that the estrogen signaling pathway, TNF signaling pathway, and osteoclast differentiation were markedly associated with ossification, and they displayed enrichment in PIK3R1. Based on western blot, qRT-PCR, and differentiation analysis in vitro, we found that upregulation of PIK3R1 enhanced osteoblastic differentiation, as evidenced by increased levels of investigated osteoblast-related genes as well as activities of ALP and ARS, while it notably decreased levels of investigated osteoclast-related genes. On the contrary, downregulation of PIK3R1 decreased levels of osteoblast-related genes and increased levels of osteoclast-related genes. Besides, in vitro experiments revealed that PIK3R1 facilitated proliferation and repressed apoptosis of osteoblasts but had an opposite impact on osteoclasts. In summary, PIK3R1 exhibits an osteoprotective effect via regulating osteoblast differentiation, which can be represented as a promising therapeutic target for osteoporosis.

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Identification of key mRNAs and lncRNAs involved in the effects of anti-TWEAK on Osteosarcoma

Current Bioinformatics ◽

10.2174/1574893615999200626191405 ◽

2020 ◽

Vol 15 ◽

Author(s):

Mingxuan Yang ◽

Liangtao Zhao ◽

Xuchang Hu ◽

Haijun Feng ◽

Xuewen Kang

Keyword(s):

Dna Replication ◽

Signaling Pathway ◽

Bioinformatics Analysis ◽

Mapk Signaling ◽

Migration And Invasion ◽

Type I ◽

Interferon Signaling ◽

Nf Kappa B ◽

Ppi Networks ◽

Coexpression Networks

Background: Osteosarcoma (OS) is one of the most common primary malignant bone tumors in teenagers. Emerging studies demonstrated TWEAK and Fn14 were involved in regulating cancer cell differentiation, proliferation, apoptosis, migration and invasion. Objective: The present study identified differently expressed mRNAs and lncRNAs after anti-TWEAK treatment in OS cells using GSE41828. Methods: We identified 922 up-regulated mRNAs, 863 downregulated mRNAs, 29 up-regulated lncRNAs, and 58 down-regulated lncRNAs after anti-TWEAK treatment in OS cells. By constructing PPI networks, we identified several key proteins involved in anti-TWEAK treatment in OS cells, including MYC, IL6, CD44, ITGAM, STAT1, CCL5, FN1, PTEN, SPP1, TOP2A, and NCAM1. By constructing lncRNAs coexpression networks, we identified several key lncRNAs, including LINC00623, LINC00944, PSMB8-AS1, LOC101929787. Result: Bioinformatics analysis revealed DEGs after anti-TWEAK treatment in OS were involved in regulating type I interferon signaling pathway, immune response related pathways, telomere organization, chromatin silencing at rDNA, and DNA replication. Bioinformatics analysis revealed differently expressed lncRNAs after antiTWEAK treatment in OS were related to telomere organization, protein heterotetramerization, DNA replication, response to hypoxia, TNF signaling pathway, PI3K-Akt signaling pathway, Focal adhesion, Apoptosis, NF-kappa B signaling pathway, MAPK signaling pathway, FoxO signaling pathway. Conclusion: : This study provided useful information for understanding the mechanisms of TWEAK underlying OS progression and identifying novel therapeutic markers for OS.

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Conditional knockout of the PDK‐1 gene in osteoblasts affects osteoblast differentiation and bone formation

Journal of Cellular Physiology ◽

10.1002/jcp.30249 ◽

2020 ◽

Author(s):

Yiguang Bai ◽

Qiong Zhang ◽

Qiaoling Chen ◽

Quan Zhou ◽

Yanan Zhang ◽

...

Keyword(s):

Bone Formation ◽

Osteoblast Differentiation ◽

Conditional Knockout

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Probiotic Propionibacterium freudenreichii MJ2 Enhances Osteoblast Differentiation and Mineralization by Increasing the OPG/RANKL Ratio

Microorganisms ◽

10.3390/microorganisms9040673 ◽

2021 ◽

Vol 9 (4) ◽

pp. 673

Author(s):

Jiah Yeom ◽

Seongho Ma ◽

Young-Hee Lim

Keyword(s):

Signaling Pathway ◽

Osteoblast Differentiation ◽

Surface Proteins ◽

Bone Morphogenetic Protein 2 ◽

Ovariectomized Rats ◽

Osteoblastic Cell ◽

Enhancement Effect ◽

Propionibacterium Freudenreichii ◽

Alizarin Red ◽

Osteoblastic Cell Line

Osteoblast differentiation is important for the development of bone and the maintenance of bone density. Propionibacterium freudenreichii is a probiotic with an anti-inflammatory property. The aim of this study was to investigate the enhancement effect of P. freudenreichii MJ2 (MJ2) isolated from raw milk on osteoblast differentiation, mineralization, and its signaling pathway. For in vitro and in vivo experiments, human fetal osteoblastic cell line hFOB 1.19 and an ovariectomized rat model were used, respectively. Expression levels of genes and proteins related to osteoblast differentiation and mineralization were measured by real-time polymerase chain reaction (qPCR) and Western blotting, respectively. Alizarin red S staining was performed to measure osteoblast mineralization. Heat-killed MJ2 (hkMJ2)-treated cells showed significantly increased osteoblast differentiation via an increase in the osteoprotegerin (OPG)/receptor activator of nuclear factor-κB ligand (RANKL) ratio and significantly increased osteoblast mineralization by stimulating the expression of bone morphogenetic protein 2 and runt-related transcription factor 2. Additionally, oral administration of live or heat-killed MJ2 to ovariectomized rats inhibited osteoporosis-induced bone loss. Specifically, surface proteins isolated from MJ2 promoted osteoblast differentiation and mineralization. In conclusion, MJ2 enhanced osteoblast differentiation and mineralization through the OPG/RANKL signaling pathway and the effective component of MJ2 might be its surface proteins.

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