Ethyl Docosahexaenoate and Its Acidic Form Increase Bone Formation by Induction of Osteoblast Differentiation and Inhibition of Osteoclastogenesis

Background/Aims: Osteoporosis is a bone metabolic disease characterized by a systemic impairment of bone mass, which results in increased propensity of fragility fractures. A reduction in the differentiation of MSCs into osteoblasts contributes to the impaired bone formation observed in osteoporosis. Mesenchymal stem cells (MSCs) are induced to differentiate into preosteoblasts, which are regulated by the signaling cascades initiated by the various signals, including miRNAs. miR-16-2* is a newly discovered miRNA that participates in diagnosis and prognosis of hepatocellular carcinoma, cervical cancer and chronic lymphocytic leukemia. However, the effect of miR-16-2* on the regulation of osteoblast differentiation and the mechanism responsible are still unclear. Here we discuss the contribution of miR-16-2* to osteoporosis, osteoblast differentiation and mineralization. Methods: The expression pattern of miR-16-2* during osteogenesis or in osteoporosis bone samples was validated by quantitative real-time PCR (qRT-PCR). The human bone marrow mesenchymal stem cells (hBMSCs) were induced to differentiate into osteoblasts by osteogenic induced medium containing dexamethasone, ascorbate-2-phosphat, beta-glycerophosphate and vitamin-D3. The target genes of miR-16-2* were predicted by TargetScan and PicTar. The mRNA and protein levels of osteogenic key markers were detected using qRT-PCR or western blot respectively. The WNT signal activity was analyzed by TOP/FOP reporter assay. Results: The expression of miR-16-2* in patient bone tissue with osteoporosis was negatively correlated with bone formation related genes. During osteoblast differentiation process, the expression of miR-16-2* was significantly decreased. Upregulation of miR-16-2* in hBMSCs impaired the osteogenic differentiation while the downregulation of miR-16-2* increased this process. Upregulation the expression of miR-16-2* could also block the WNT signal pathway by directly target WNT5A. Furthermore, knockdown of miR-16-2* could promote the activation of RUNX2, possibly by lifting the inhibitory effect of miR-16-2* on WNT pathway. Conclusion: Taken together, we report a novel biological role of miR-16-2* in osteogenesis through regulating WNT5A response for the first time. Our data support the potential utilization of miRNA-based therapies in regenerative medicine.

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Effects of Farnesyl Pyrophosphate Accumulation on Calvarial Osteoblast Differentiation

Endocrinology ◽

10.1210/en.2011-0016 ◽

2011 ◽

Vol 152 (8) ◽

pp. 3113-3122 ◽

Cited By ~ 21

Author(s):

Megan M. Weivoda ◽

Raymond J. Hohl

Keyword(s):

Bone Formation ◽

Osteoblast Differentiation ◽

Biosynthetic Pathway ◽

Squalene Synthase ◽

Farnesyl Pyrophosphate ◽

Matrix Mineralization ◽

Lower Serum Cholesterol ◽

Calvarial Osteoblast ◽

Isoprenoid Biosynthetic Pathway

Statins, drugs commonly used to lower serum cholesterol, have been shown to stimulate osteoblast differentiation and bone formation. Statins inhibit 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A reductase (HMGCR), the first step of the isoprenoid biosynthetic pathway, leading to the depletion of the isoprenoids farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). The effects of statins on bone have previously been attributed to the depletion of GGPP, because the addition of exogenous GGPP prevented statin-stimulated osteoblast differentiation in vitro. However, in a recent report, we demonstrated that the specific depletion of GGPP did not stimulate but, in fact, inhibited osteoblast differentiation. This led us to hypothesize that isoprenoids upstream of GGPP play a role in the regulation of osteoblast differentiation. We demonstrate here that the expression of HMGCR and FPP synthase decreased during primary calvarial osteoblast differentiation, correlating with decreased FPP and GGPP levels during differentiation. Zaragozic acid (ZGA) inhibits the isoprenoid biosynthetic pathway enzyme squalene synthase, leading to an accumulation of the squalene synthase substrate FPP. ZGA treatment of calvarial osteoblasts led to a significant increase in intracellular FPP and resulted in inhibition of osteoblast differentiation as measured by osteoblastic gene expression, alkaline phosphatase activity, and matrix mineralization. Simultaneous HMGCR inhibition prevented the accumulation of FPP and restored osteoblast differentiation. In contrast, specifically inhibiting GGPPS to lower the ZGA-induced increase in GGPP did not restore osteoblast differentiation. The specificity of HMGCR inhibition to restore osteoblast differentiation of ZGA-treated cultures through the reduction in isoprenoid accumulation was confirmed with the addition of exogenous mevalonate. Similar to ZGA treatment, exogenous FPP inhibited the mineralization of primary calvarial osteoblasts. Interestingly, the effects of FPP accumulation on osteoblasts were found to be independent of protein farnesylation. Our findings are the first to demonstrate that the accumulation of FPP impairs osteoblast differentiation and suggests that the depletion of this isoprenoid may be necessary for normal and statin-induced bone formation.

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Graphene-Based MicroRNA Transfection Blocks Preosteoclast Fusion to Increase Bone Formation and Vascularization

Advanced Science ◽

10.1002/advs.201700578 ◽

2017 ◽

Vol 5 (2) ◽

pp. 1700578 ◽

Cited By ~ 29

Author(s):

Ce Dou ◽

Ning Ding ◽

Fei Luo ◽

Tianyong Hou ◽

Zhen Cao ◽

...

Keyword(s):

Bone Formation ◽

Increase Bone Formation

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The Effect of the Combination of Vitamin K2 and Genistein, Coumestrol and Daidzein on the Osteoblast Differentiation and Bone Matrix Formation

Journal of Biotechnology Research Center ◽

10.24126/jobrc.2016.10.2.474 ◽

2016 ◽

Vol 10 (2) ◽

pp. 12-19

Author(s):

Sahar S. Karieb ◽

Mohammed M. Jawad ◽

Hanady S. Al-Shmgani ◽

Zahraa H.M. Kadri

Keyword(s):

Bone Formation ◽

Osteoblast Differentiation ◽

Nuclear Factor Kappa B ◽

Type I Collagen ◽

Bone Mineralization ◽

Bone Matrix ◽

Vitamin K2 ◽

Type I ◽

Nuclear Factor ◽

Effective Factor

Multiple studies have been reported the stimulatory effect of the combinations of nutrients factors on bone formation. One such factor is vitamin K2 which can be associated with bone protective activities. The effect of vitamin K2 alone and in combination with genistein, coumestrol and daidzein on osteoblast differentiation and mineralization were tested. Significantly, vitamin K2 increased bone mineralization in combination with genistein (10-5M), coumestrol (10-7M) and daidzein (10-5M). However, there is no additive effect of this vitamin on alkaline phosphatase (ALP) levels in osteoblasts. By contrast, vitamin K2 enhanced the stimulatory effect of type I collagen and osteocalcin expression. Vitamin K2 alone increased RUNX and OSX expression while there is no synergistic effect with tested compound; this vitamin also did not modulate nuclear factor kappa B ligand (RANKL)/ osteoprotegerin (OPG) ratio expression. These results suggested that vitamin K2 can be more effective factor in the presence of phytoestrogens on the improvement of bone formation after menopause.

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