High water-soluble curcuminoids-rich extract regulates osteogenic differentiation of MC3T3-E1 cells: Involvement of Wnt/β-catenin and BMP signaling pathway / 中草药·英文版

Objective: The present study aimed to evaluate the effect of a high water-soluble curcuminoids-rich extract (CRE) in a solid dispersion form (CRE-SD) using polyvinylpyrrolidone K30 on osteogenic induction of MC3T3-E1 cells. Methods: CRE was pre-purified using a microwave assisted extraction couple with a Diaion® HP-20 column chromatography. The osteoblastic cell proliferation and differentiation potentials of CRE-SD in MC3T3-E1 cells were tested by cell viability, alkaline phosphatase (ALP) activity, and Alizarin red S activity assays. The mRNA expressions of osteoblast-specific genes and underline mechanisms were assessed by a real time PCR and western blot analysis. Results: CRE-SD 50 µg/mL increased alkaline phosphatase (ALP) activity, an early differentiation marker of osteoblasts in both MC3T3-E1 cells and non-osteogenic mouse pluripotent cell line, C3H10T1/2, indicating the action of CRE-SD was not cell-type specific. Alizarin red S activity showed a significant amount of calcium deposition in cells treated with CRE-SD. CRE-SD also upregulated the mRNA expression levels of transcription factors that favor osteoblast differentiation including Bmp-2, Runx2 and Collagen 1a, in a dose dependent manner. Western blot analysis revealed that noggin attenuated CRE-SD-promoted expressions of Bmp-2 and Runx2 proteins. siRNA mediated blocking of Wnt/β-catenin signaling pathway also annulled the influence of CRE-SD, indicating Wnt/β-catenin dependent activity. Inhibition of the different signaling pathways abolished the influence of CRE-SD on ALP activity, confirming that CRE-SD induced MC3T3-E1 cells into osteoblasts through Wnt/β-catenin and BMP signaling pathway. Conclusion: These results collectively demonstrate that CRE-SD may be a potential therapeutic agent for the treatment of osteoporosis.

Bone morphogenetic proteins and inner ear development / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Bone morphogenetic proteins (BMPs) are the largest subfamily of the transforming growth factor-β superfamily, and they play important roles in the development of numerous organs, including the inner ear. The inner ear is a relatively small organ but has a highly complex structure and is involved in both hearing and balance. Here, we discuss BMPs and BMP signaling pathways and then focus on the role of BMP signal pathway regulation in the development of the inner ear and the implications this has for the treatment of human hearing loss and balance dysfunction.

Bone morphogenetic proteins and inner ear development / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Bone morphogenetic proteins (BMPs) are the largest subfamily of the transforming growth factor-β superfamily, and they play important roles in the development of numerous organs, including the inner ear. The inner ear is a relatively small organ but has a highly complex structure and is involved in both hearing and balance. Here, we discuss BMPs and BMP signaling pathways and then focus on the role of BMP signal pathway regulation in the development of the inner ear and the implications this has for the treatment of human hearing loss and balance dysfunction.

Changes of BMP signaling pathway in mammary glands of mice with mammary hyperplasia / 中国病理生理杂志

AIM:To determine the expression patterns of bone morphogenetic protein(BMP)signaling com-ponents in the mammary glands with hyperplasia(MGH)and the activation of this signaling pathway.METHODS: The female C57BL/C mice(8-weeks-old)were randomly divided into control group and hormone group with 15 mice in each group.The mice in control group were treated with PBS,while the mice in hormone group were intragastric administration with estradiol valerate(2.5 mg/kg)for 25 d,followed by progesterone(4 mg/kg)peritoneal injection for 5 d.At the end of treatments,the mammary glands were collected to determine the morphological changes, the mRNA expression of BMP signaling components and the phosphorylation level of Smad 1/5/9.RESULTS:In MGH,a part of BMP signaling pathway molecules were differentially expressed(P<0.05),including BMP ligands BMP2,4,5,6,7,9,13 and 14, BMP re-ceptor BMPR1A, and antagonists Chrdl1 and Twsg, whereas the expression levels of some molecules, such as BMP3, BMP12,BMPR1B,BMPR2,Chrd,Chrdl2 and Noggin, were not altered.The phosphorylation levels of Smad 1/5/9 was up-regulated in MGH(P<0.05).CONCLUSION: BMP signaling pathway is activated in MGH through the abnormal expression of its components.BMP signaling pathway may be a new target for MGH therapy.

Effect of Noggin silencing on the BMP and Wnt signaling pathways / 中国实验动物学报

Objective To analyze the effect of Noggin silencing on the BMP and Wnt signaling pathways in hair follicle development.Methods The expression of BMP-2, BMP-4, BMPR-IA, BMP-6, BMP-7, LEF-1 andβ-catenin in Noggin silencing MC3T3-E1 stable cell line was detected by RT-PCR and western blot.Results RT-PCR results showed that the expressions of five genes in BMP signaling pathway were all significantly influenced by Noggin silencing, the ex-pressions of BMP-2 (P<0.001), BMP-4 (P<0.01), BMP-6 (P<0.001) and BMP-7 (P<0.001) were all increased and the expression of BMPR-IA (P<0.01) was decreased.While the expressions of the two genes LEF-1 (P<0.001) and β-catenin ( P<0.001) in Wnt signaling pathway were significantly decreased.Western blot results showed that the ex-pressions of these proteins in the two signaling pathways were also affected.The expressions of BMP-2 (P<0.05), BMP-4 (P<0.05), BMP-6 (P<0.05) and BMP-7 (P<0.05) were all increased, while the expressions of BMPR-IA (P<0.05), LEF-1 (P<0.01) andβ-catenin (P<0.001) were decreased.Conclusions There may be a negative feedback regulation of Noggin on the BMP signaling pathway in vitro, but a positive feedback regulation on the Wnt signaling pathway in vitro.It provides certain evidence for studies on the effect of Noggin gene on BMP and Wnt signaling pathways in vivo. There may be an interaction between hair follicle development-related signaling pathways, which still needs further experi-ments to prove.

Requirement of Smad4-mediated signaling in odontoblast differentiation and dentin matrix formation / 대한해부학회지

Dentin is the major part of tooth and formed by odontoblasts. Under the influence of the inner enamel epithelium, odontoblasts differentiate from ectomesenchymal cells of the dental papilla and secrete pre-dentin which then undergo mineralization into dentin. Transforming growth factor-beta (TGF-β)/bone morphogenetic protein (BMP) signaling is essential for dentinogenesis; however, the precise molecular mechanisms remain unclear. To understand the role of TGF-β/BMP signaling in odontoblast differentiation and dentin formation, we generated mice with conditional ablation of Smad4, a key intracellular mediator of TGF-β/BMP signaling, using Osr2 or OC-Cre mice. Here we found the molars of Osr2(Cre)Smad4 mutant mice exhibited impaired odontoblast differentiation, and normal dentin was replaced by ectopic bone-like structure. In Osr2(Cre)Smad4 mutant mice, cell polarity of odontoblast was lost, and the thickness of crown dentin was decreased in later stage compared to wild type. Moreover, the root dentin was also impaired and showed ectopic bone-like structure similar to Osr2(Cre)Smad4 mutant mice. Taken together, our results suggest that Smad4-dependent TGF-β/BMP signaling plays a critical role in odontoblast differentiation and dentin formation during tooth development.

Anthraquinone Glycoside Aloin Induces Osteogenic Initiation of MC3T3-E1 Cells: Involvement of MAPK Mediated Wnt and Bmp Signaling

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.

Progress in impact mechanism of CKIP-1 gene on osteoporosis / 国际生物医学工程杂志

Osteoporosis (OP) is one of the bone metabolic diseases which seriously harms the health and lives of people. The main cause of OP is that the balance between bone formation and bone absorption, i.e. the balance of the bone remodeling process,is no longer exist. When the bone absorption dominates the process, it will lead to osteopenia, destruction of bone microstructure and increased rate of fracture. Previous studies have shown that casein kinase 2-interacting protein-1 (CKIP-1) plays an important role in the process of bone tissue proliferation and differentiation. It mainly interacts with Smad ubiquitination regulatory factor 1 (Smurf 1) to affect bone metabolism. This review analyzes and summarizes the impact of CKIP-1 on bone tissue osteogenic differentiation direction and its mechanism, which may provide new idea and research orientation for future clinical treatment of osteoporosis.

Calycosin-7-O-β-d-glucopyranoside stimulates osteoblast differentiation through regulating the BMP/WNT signaling pathways

The isoflavone calycosin-7-O-β-d-glucopyranoside (CG) is a principal constituent of Astragalus membranaceus (AR) and has been reported to inhibit osteoclast development in vitro and bone loss in vivo. The aim of this study was to investigate the osteogenic effects of CG and its underlying mechanism in ST2 cells. The results show that exposure of cells to CG in osteogenic differentiation medium increases ALP activity, osteocalcin (Ocal) mRNA expression and the osteoblastic mineralization process. Mechanistically, CG treatment increased the expression of bone morphogenetic protein 2 (BMP-2), p-Smad 1/5/8, β-catenin and Runx2, all of which are regulators of the BMP- or wingless-type MMTV integration site family (WNT)/β-catenin-signaling pathways. Moreover, the osteogenic effects of CG were inhibited by Noggin and DKK-1 which are classical inhibitors of the BMP and WNT/β-catenin-signaling pathways, respectively. Taken together, the results indicate that CG promotes the osteoblastic differentiation of ST2 cells through regulating the BMP/WNT signaling pathways. On this basis, CG may be a useful lead compound for improving the treatment of bone-decreasing diseases and enhancing bone regeneration.