• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1183-1186
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• 2012

Objective: To observe the effect of insulin-like growth factor-1 (IGF-1) on bone morphogenetic protein (BMP)-2 expression in hepatocellular carcinoma SMMC7721 cells. Methods: Cells were divided into blank control, IGF-1, IGF-1 + SB203580, and SB203580 groups. SB203580 was used to block the p38 MAPK signaling pathway. Changes in the expression of BMP-2, p38 MAPK, and phosphorylated p38, MERK, ERK and JNK were determined using reverse transcription polymerase chain reactions (RT-PCR) and Western blot analysis. Results: Protein expression of phosphorylated BMP-2, MERK, ERK, and JNK was significantly up-regulated by IGF-1 compared with the control group ($1.138{\pm}0.065$ vs. $0.606{\pm}0.013$, $0.292{\pm}0.005$ vs. $0.150{\pm}0.081$, $0.378{\pm}0.006$ vs. $0.606{\pm}0.013$, and $0.299{\pm}0.015$ vs. $0.196{\pm}0.017$, respectively; P<0.05). Levels of BMP-2 and phosphorylated MERK and JNK were significantly reduced after blocking of the p38MAPK signaling pathway ($0.494{\pm}0.052$ vs. $0.165{\pm}0.017$, $0.073{\pm}0.07$ vs. $0.150{\pm}0.081$, and $0.018{\pm}0.008$ vs. $0.196{\pm}0.017$, respectively; P<0.05), but such a significant difference was not observed for phosphorylated ERK protein expression ($0.173{\pm}0.07$ vs. $0.150{\pm}0.081$, P>0.05). Conclusion: IGF-1 can up-regulate BMP-2 expression, and p38 MAPK signaling pathway blockage can noticeably reduce the up-regulated expression. We can conclude that the up-regulatory effect of IGF-1 on BMP-2 expression is realized through the p38 MAPK signaling pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.5
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• pp.447-453
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• 2013

Osteoblastic activity of nectandrin A was examined in C2C12 cells. Nectandrin A enhances the BMP-induced osteoblastic differentiation and mineralization, manifested by the up-regulation of differentiation markers (alkaline phosphatase and osteogenic genes) and increased calcium contents. In C2C12 cells co-transfected with expression vector encoding Smad4 and Id1-Luc reporter, nectandrin A increased Id1 luciferase activity in a concentration-dependent manner, when compared to that in BMP-2 treated cells, indicating that Smad signaling pathway is associated with nectandrin A-enhanced osteoblastic differentiation in C2C12 cells. In addition, nectandrin A activated p38 mitogen-activated protein kinase (MAPK) in time- and concentration-dependent manners, and phosphorylated form of pSmad1/5/8 and alkaline phosphatase activity were both decreased when the cells were pretreated with SB203580, a p38 MAPK inhibitor, suggesting that p38 MAPK might be an upstream kinase for Smad signaling pathway. Taken together, nectandrin A enhances the BMP-induced osteoblastic differentiation and mineralization of C2C12 cells via activation of p38 MAPK-Smad signaling pathway, and it has a therapeutic potential for osteoporosis by promoting bone formation.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.3
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• pp.197-206
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• 2021

Carnosol is a phenolic diterpene phytochemical found in rosemary and sage with reported anti-microbial, anti-oxidant, anti-inflammatory, and anti-carcinogenic activities. This study aimed to investigate the effect of carnosol on the lineage commitment of mouse bone marrow-derived mesenchymal stem cells (mBMSCs) into osteoblasts and adipocytes. Interestingly, carnosol stimulated the early commitment of mBMSCs into osteoblasts in dose-dependent manner as demonstrated by increased levels of alkaline phosphatase activity and Alizarin red staining for matrix mineralization. On the other hand, carnosol significantly suppressed adipogenesis of mBMSCs and downregulated both early and late markers of adipogenesis. Carnosol showed to induce osteogenesis in a mechanism mediated by activating BMP signaling pathway and subsequently upregulating the expression of BMPs downstream osteogenic target genes. In this context, treatment of mBMSCs with LDN-193189, BMPR1 selective inhibitor showed to abolish the stimulatory effect of carnosol on BMP2-induced osteogenesis. In conclusion, our data identified carnosol as a novel osteoanabolic phytochemical that can promote the differentiation of mBMSCs into osteoblasts versus adipocytes by activating BMP-signaling.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.23-30
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• 2018

Purpose: Runx2 (runt-related transcription factor 2), a bone-specific transcription factor, is a key regulator of osteoblast differentiation and its expression is induced by the activation of BMP-2 signaling. This study examined whether zinc modulates BMP-2 signaling and therefore stimulates Runx2 and osteoblast differentiation gene expression. Methods: Two osteoblastic MC3T3-E1 cell lines (subclones 4 as a high osteoblast differentiation and subclone 24 as a low osteoblastic differentiation) were cultured in an osteogenic medium (OSM) as the normal control, Zn-($1{\mu}M$ Zn) or Zn+($15{\mu}M$ Zn) for 24 h. The genes and proteins for BMP-2 signaling (BMP-2, Smad-1/p-Smad-1), transcription factors (Runx2, osterix), and osteoblast differentiation marker proteins were assessed. Results: In both cell lines, BMP-2 mRAN and protein expression and extracellular BMP-2 secretion all decreased in Zn-. The expression of Smad-1 (downstream regulator of BMP-2 signaling) and p-Smad-1 (phosphorylated Smad-1) also downregulated in Zn-. Furthermore, the expression of the bone-specific transcription factors, Runx2 and osterix, decreased in Zn-, which might be due to the decreased BMP-2 expression and Smad-1 activation (p-Smad-1) by Zn-, because Runx2 and osterix both are downstream in BMP-2 signaling. Bone marker gene expression, such as alkaline phosphatase (ALP), collagen type I (COLI), osteocalcin, and osteopontin were also downregulated in Zn-. Conclusion: The results suggest that a zinc deficiency in osteoblasts suppresses the BMP-2 signaling pathway via the suppression of Smad-1 activation, and this suppressed BMP-2 signaling can cause poor osteoblast differentiation.

• Molecules and Cells
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• v.22 no.3
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• pp.353-359
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• 2006

The bone morphogenetic protein (BMP) family has been implicated in control of cartilage development. Here, we demonstrate that BMP-2 promotes chondrogenesis by activating p38 mitogen-activated protein kinase (MAPK), which in turn downregulates $Wnt-7a/{\beta}$-catenin signaling responsible for proteasomal degradation of Sox9. Exposure of mesenchymal cells to BMP-2 resulted in upregulation of Sox9 protein and a concomitant decrease in the level of ${\beta}$-catenin protein and Wnt-7a signaling. In agreement with this, the interaction of Sox9 with ${\beta}$-catenin was inhibited in the presence of BMP-2. Inhibition of the p38 MAPK pathway using a dominant negative mutant led to sustained Wnt-7a signaling and decreased Sox9 expression, with consequent inhibition of precartilage condensation and chondrogenic differentiation. Moreover, overexpression of ${\beta}$-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway. Our results collectively indicate that the increase in Sox9 protein resulting from downregulation of ${\beta}$-catenin/Wnt-7a signaling is mediated by p38 MAPK during BMP-2 induced chondrogenesis in chick wing bud mesenchymal cells.

• International Journal of Stem Cells
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• v.15 no.2
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• pp.144-154
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• 2022

Background and Objectives: Neural stem cells (NSCs) remain in the mammalian brain throughout life and provide a novel therapeutic strategy for central nervous system (CNS) injury. Bone morphogenetic protein-6 (BMP-6) had shown a protective effect in different types of cells. However, the role of BMP-6 in NSCs is largely unclear. The present study was aimed to investigate whether BMP-6 could protect human NSCs (hNSCs) against the oxygen and glucose deprivation (OGD)-induced cell death. Methods and Results: Upon challenge with OGD treatment, cell viability was significantly decreased in a time-dependent manner, as indicated by the CCK-8 assay. BMP-6 could attenuate the OGD-induced cell injury in a dose-dependent manner and decrease the number of TUNEL-positive cells. Moreover, BMP-6 markedly weakened the OGD-induced alterations in the expression of procaspase-8/9/3 and reversed the expression of cleaved-caspase-3. Interestingly, noggin protein (the BMP-6 inhibitor) attenuated the neuroprotective effect of BMP-6 in cultured hNSCs. Furthermore, the p38 MAPK signaling pathway was activated by OGD treatment and BMP-6 markedly inhibited the phosphorylation of p38 in a concentration-dependent manner. Pretreatment with noggin abolished the effect of BMP-6 on p38 activation. SB239063, a selective p38 inhibitor, exerted similar effects with BMP-6 in protecting hNSCs against the OGD-induced apoptosis. These results indicated that blocking the phosphorylation of p38 might contribute to the neuroprotective effect of BMP-6 against the OGD-induced injury in hNSCs. Conclusions: These findings suggested that BMP-6 might be a therapeutic target in the OGD-induced cell death, which provides a novel therapeutic strategy for enhancing host and graft NSCs survival in hypoxic-ischemic brain injury.

• Molecules and Cells
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• v.37 no.3
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• pp.270-274
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• 2014

Lymphatic vessels are essential to regulate interstitial fluid homeostasis and diverse immune responses. A number of crucial factors, such as VEGFC, SOX18, PROX1, FOX2C, and GJC2, have been implicated in differentiation and/or maintenance of lymphatic endothelial cells (LECs). In humans, dysregulation of these genes is known to cause lymphedema, a debilitating condition which adversely impacts the quality of life of affected individuals. However, there are no currently available pharmacological treatments for lymphedema, necessitating identification of additional factors modulating lymphatic development and function which can be targeted for therapy. In this report, we investigate the function of genes associated with Bone Morphogenetic Protein (BMP) signaling in lymphatic development using zebrafish embryos. The knock-down of BMP type II receptors, Bmpr2a and Bmpr2b, and type I receptors, Alk3 and Alk3b, as well as SMAD5, an essential cellular mediator of BMP signaling, led to distinct lymphatic defects in developing zebrafish. Therefore, it appears that each constituent of the BMP signaling pathway may have a unique function during lymphatic development. Taken together, our data demonstrate that BMP signaling is essential for normal lymphatic vessel development in zebrafish.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.1
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• pp.1-5
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• 2017

Bone morphogenetic protein 2 (BMP2) plays an important role in the development of bone and cartilage. It is involved in the hedgehog pathway, TGF beta signaling pathway, and in cytokine-cytokine receptor interaction. It is involved also in cardiac cell differentiation and epithelial to mesenchymal transition. In this study, We expressed human BMP2 (hBMP2) recombinant protein using Baculovirus Expression Vector System (BEVS) in Sf9 insect cells. The hBMP2 cDNA was cloned into baculovirus transfer vector, pBacgus-4x-1 and recombinant baculovirus was screened out through X-gal and GUS-fusions assay. Western blot analysis shown that molecular weight of hBMP2 recombinant protein was about 44.71 kDa.

• Biomolecules & Therapeutics
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• v.24 no.2
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• pp.123-131
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• 2016

Osteoporosis is a bone pathology leading to increased fracture risk and challenging the quality of life. The aim of this study was to evaluate the effect of an anthraquinone glycoside, aloin, on osteogenic induction of MC3T3-E1 cells. Aloin increased alkaline phosphatase (ALP) activity, an early differentiation marker of osteoblasts. Aloin also increased the ALP activity in adult human adipose-derived stem cells (hADSC), indicating that the action of aloin was not cell-type specific. Alizarin red S staining revealed a significant amount of calcium deposition in cells treated with aloin. Aloin enhanced the expression of osteoblast differentiation genes, Bmp-2, Runx2 and collagen 1a, in a dose-dependent manner. Western blot analysis revealed that noggin and inhibitors of p38 MAPK and SAPK/JNK signals attenuated aloin-promoted expressions of Bmp-2 and Runx2 proteins. siRNA mediated blocking of Wnt-5a signaling pathway also annulled the influence of aloin, indicating Wnt-5a dependent activity. Inhibition of the different signal pathways abrogated the influence of aloin on ALP activity, confirming that aloin induced MC3T3-E1 cells into osteoblasts through MAPK mediated Wnt and Bmp signaling pathway.

• BMB Reports
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• v.55 no.11
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• pp.565-570
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• 2022

Pulmonary arterial hypertension (PAH) is a progressive and devastating disease whose pathogenesis is associated with a phenotypic switch of pulmonary arterial vascular smooth muscle cells (PASMCs). Bone morphogenetic protein (BMP) signaling and potassium two pore domain channel subfamily K member 3 (KCNK3) play crucial roles in PAH pathogenesis. However, the relationship between BMP signaling and KCNK3 expression in the PASMC phenotypic switching process has not been studied. In this study, we explored the effect of BMPs on KCNK3 expression and the role of KCNK3 in the BMP-mediated PASMC phenotypic switch. Expression levels of BMP receptor 2 (BMPR2) and KCNK3 were downregulated in PASMCs of rats with PAH compared to those in normal controls, implying a possible association between BMP/BMPR2 signaling and KCNK3 expression in the pulmonary vasculature. Treatment with BMP2, BMP4, and BMP7 significantly increased KCNK3 expression in primary human PASMCs (HPASMCs). BMPR2 knockdown and treatment with Smad1/5 signaling inhibitor substantially abrogated the BMP-induced increase in KCNK3 expression, suggesting that KCNK3 expression in HPASMCs is regulated by the canonical BMP-BMPR2-Smad1/5 signaling pathway. Furthermore, KCNK3 knockdown and treatment with a KCNK3 channel blocker completely blocked BMP-mediated anti-proliferation and expression of contractile marker genes in HPAMSCs, suggesting that the expression and functional activity of KCNK3 are required for BMP-mediated acquisition of the quiescent PASMC phenotype. Overall, our findings show a crosstalk between BMP signaling and KCNK3 in regulating the PASMC phenotype, wherein BMPs upregulate KCNK3 expression and KCNK3 then mediates BMP-induced phenotypic switching of PASMCs. Our results indicate that the dysfunction and/or downregulation of BMPR2 and KCNK3 observed in PAH work together to induce aberrant changes in the PASMC phenotype, providing insights into the complex molecular pathogenesis of PAH.