Bone Morphogenetic Protein Receptor in the Osteogenic Differentiation of Rat Bone Marrow Stromal Cells

PURPOSE: Several signaling pathways have been shown to regulate the lineage commitment and terminal differentiation of bone marrow stromal cells (BMSCs). Bone morphogenetic protein (BMP) signaling has important effects on the process of skeletogenesis. In the present study, we tested the role of bone morphogenetic protein receptor (BMPR) in the osteogenic differentiation of rat bone marrow stromal cells in osteogenic medium (OM) with or without BMP-2. MATERIALS AND METHODS: BMSCs were harvested from rats and cultured in OM containing dexamethasone, beta-glycerophosphate, and ascorbic acid, with or without BMP-2 in order to induce osteogenic differentiation. The alkaline phosphatase (ALP) activity assay and von kossa staining were used to assess the osteogenic differentiation of the BMSCs. BMPR mRNA expression was assessed using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The BMSCs that underwent osteogenic differentiation in OM showed a higher level of ALP activity and matrix mineralization. BMP-2 alone induced a low level of ALP activity and matrix mineralization in BMSCs, but enhanced the osteogenic differentiation of BMSCs when combined with OM. The OM significantly induced the expression of type IA receptor of BMPR (BMPRIA) and type II receptor of BMPR (BMPRII) in BMSCs after three days of stimulation, while BMP-2 significantly induced BMPRIA and BMPRII in BMSCs after nine or six days of stimulation, respectively. CONCLUSION: BMSCs commit to osteoblastic differentiation in OM, which is enhanced by BMP-2. In addition, BMP signaling through BMPRIA and BMPRII regulates the osteogenic differentiation of rat BMSCs in OM with or without BMP-2.

Uso da BMP-2 e 7 na promoção da osseointegração às superfícies dos implantes de titânio / The usage of BMP-2 and 7 for the promotion of the osseointegration to titanium implants surfaces

Para que seja possível a instalação dos implantes, há necessidade de que exista tecido ósseo de boa qualidade. Sem isto, as possibilidades de osseointegração e, portanto, de sucesso são muito reduzidas. As proteínas morfogenéticas ósseas (BMPs) são substâncias osteoindutoras e têm sido utilizadas na regeneração periodontal e na osseointegração. Em função disto, foi realizada uma revisão de literatura para analisar a influência da BMP-2 e 7 na osseointegração da superfície dos implantes com o osso neoformado. As BMP-2 e 7 promovem uma neoformação óssea, produzindo uma área propícia para a instalação dos implantes. Além disso, estas proteínas permitem uma melhor osseointegração com a superfície de titânio, acelerando-a e possibilitando uma adaptação precoce às cargas funcionais. A aplicação da BMP-2 ou 7 pode ter utilidade clínica, no caso os implantes, além de ser uma alternativa para os enxertos ósseos autógenos. Novos estudos são necessários para analisar a viabilidade e o sucesso da aplicação destas proteínas no caso de implantes intra-orais em humanos.

For the implants installation to be possible there is a need for a good quality osseous tissue to exist. Without this, the possibilities of osseointegration and, therefore, the success, are much reduced. The bone morphogenetic proteins (BMPs) are osseous inducers substances and have been used in the periodontal regeneration and in the osseointegration. In function of that, a literature revision was carried out to analyze the influence of BMP-2 and 7 in the osseointegrationof implants surface, with the neoformed bone. The BMP-2 and 7 promote a bone neoformation, thus producing an adequate area for the implants installation. Besides that, these proteins allow a better osseointegration with the titanium surface, expediting it and enabling a precocious adaptation to the functional loads. The application of BMP-2 or 7 can have clinical utility, in this case the implants, besides being an alternative for the autogenous osseous grafts. New studies are necessary to analyze the viability and the success of these proteins application, in case of intraoral implants in humans.

Expressão da proteínas ciclina B1, Rb1, P27, BMP4 e LCA no grnauloma piogênico, no fibroma ossficante periférico e no granuloma piogênico com calcificações / Expresision of the proteins cyclin B1, Rb1, P27, BMP4 and LCA in pyogenic granuloma, peripheral ossifynig fibroma and pyogenic granuloma with calcification

Foi realizada neste estudo uma análise da expressão das proteínas ciclina B1, Rb1 (gene do retinoblastoma 1), P27 (proteina 27), BMP4 (proteina morfogenética do osso) e LCA (antígeno leucocitário comum), pelo método imunoistoquímico da dupla marcação, em 24 casos de lesões proliferativas gengivais, divididas em três grupos de acordo com suas características histopatológicas: Grupo I (granuloma piogênico), Grupo II (fibroma ossificante periférico) e Grupo III (granuloma piogênico com calcificações). O LCA foi empregado como primeiro anti-corpo primário em todos as espécimes. Os genes ciclina B1, P27 e Rb1 têm um papel crítico na regulação da transição das fases do ciclo celular e frequentemente estão alterados em várias entidades neoplásicas. Portanto, foi objetivo do presente trabalho a comparação da expressão de tais proteínas entre as três lesões para obter informações sobre a atividade proliferativa das células presentes no tecido. O anticorpo anti-BMP4 foi empregado com o objetivo de avaliar e comparar sua expressão no estroma das lesões que produzem material mineralizado. Os resultados demonstraram semelhança quanto à expressão das proteínas ciclina B1, Rb1, P27 e LCA nas lesões do Grupo 1 e do Grupo III e expressão distinta em relação as lesões do Grupo II. A expressão da proteína BMP4 nas lesões dos Grupos II e III sugere origens diferentes para o material mineralizado de tais lesões. A ausência de expressão da proteína BMP4 nas lesões do Grupo I confrima a ausência de células osteoprogenitoras em seu estroma

Content of bone morphogenetic protein-4 in human demineralized bone: relationship to donor age and ability to induce new bone formation.

BACKGROUND: Bone morphogenetic proteins (BMPs) are also called growth and differentiation factors (GDFs) and form a subfamily of related proteins within the TGF-beta superfamily. BMP-4 is one ofmultifuntional growth factors with pleiotropic roles in many different cell types and is predominantly present in human bone tissue. OBJECTIVES: To analyze the content of extractable BMP-4 in human demineralized bone as a function of age. MATERIAL AND METHOD: Bone samples were ground and demineralized by exposure to 0.5 N HCl and then extracted by collagenase digestion. Extractable BMP-4 was analyzed using a commercially available enzyme-linked immunosorbent assay (ELISA). RESULTS: 63 samples of demineralized bone matrix (DBM) derived from 36 men and 27 women between the ages of 15-65 years. The extractable BMP-4 content appears to be age-dependent, with DBM from younger donors being most likely to have higher BMP-4 quantity. In addition, DBM with high osteoinductivity contained greater amounts of extractable BMP-4 than DBM samples with low osteoinductivity. CONCLUSION: The BMP-4 in demineralized bone undergoes age-related decrease that may contribute to the reduction of bone volume observed with aging.

A study on myocardial Pax-8 gene / 中华儿科杂志

<p><b>OBJECTIVE</b>Conventional deletion of ALK3, also termed as bone morphogenetic protein (BMP) receptor IA, in mice might result in early embryonic lethality. To investigate the function of ALK3 in cardiac development, the cardiac-specific deletion of ALK3 in mice was made by Dr. Schneider, using Cre recombinase driven by the alpha-MHC promoter that Dr. Fukushipe worked out. Such specific deletion of ALK3 caused death in mid-gestation with defects in the trabeculae, interventricular septum, and endocardial cushion. Since ALK3 is not a cardiac-specific gene, it is extremely important to identify ALK3 downstream genes.</p><p><b>METHODS</b>Alpha-MHC Cre+/-, ALK3 F/- and alpha-MHC Cre+/-, ALK3 F/+ embryos were obtained after 20 alpha-MHC Cre+/-, ALK3 +/- mice and 20 ALK3 F/F mice were mating. The ALK3 downstream genes were screened using microarray made in Germany that could identify 25000 genes in mouse. Two populations of mRNA, one derived from the embryonic heart (11.5 days) of alpha-MHC Cre+/-, ALK3 F/- mice, and the other derived from the alpha-MHC Cre+/-, ALK3 F/+ mice, were compared. Cardiac-specific ALK3 downstream genes were identified using real time quantitative RT-PCR and in situ hybridization.</p><p><b>RESULTS</b>The expression of 12 genes, such as Pax-8 and Hox-3.5 were down-regulated in alpha-MHC Cre+/-, ALK3 F/- mouse heart. The expression of 16 genes including Ras-related protein Rab-5b and EPS-8 protein was up-regulated in the group of alpha-MHC Cre+/-, ALK3 F/-. It was found that the Box protein Pax-8 gene was down-regulated by 7.1 fold (P < 0.001) in the alpha-MHC Cre+/-, ALK3 F/- mice by real time quantitative RT-PCR. It was also revealed that the Box protein Pax-8 gene was expressed stronger in alpha-MHC Cre+/-, ALK3 F/+ than alpha-MHC Cre+/-, ALK3 F/- E11.5 days mouse heart by means of in situ hybridization.</p><p><b>CONCLUSION</b>The Box protein Pax-8 gene is an important and cardiac-specific ALK3 downstream gene in the BMP signaling pathway during inter-ventricular septum development.</p>

Response of Human Renal Cell Carcinoma Cells to Bone Morphogenetic Proteins, and the Expression of Bone Morphogenetic Protein Receptors / 대한비뇨기과학회지

PURPOSE: Bone morphogenetic protein (BMP) is a pleiotropic growth factor, which has been suggested to play a critical role during the development and homeostasis of the kidney. We evaluated the response of the human renal cell carcinoma (RCC) cell lines to BMPs. MATERIALS AND METHODS: We evaluated the growth rate of the human RCC cell lines, 112, 117 and 181, according to the concentrations of BMP-4, -6 and -7, and detected the levels of the BMP receptors (BMPRs) expressed in the cell lines. To demonstrate that the defect in BMP-6 signaling is at the receptor level, BMP-6 resistant cell lines were transfected, with adenovirus containing the constitutively active form of the BMP receptor types II (BMPR-II). After transfection, the cells were transfected with pSBE4, the construct of the BMP-6-responsive luciferase reporter gene, and a luciferase assay performed. RESULTS: The BMP-6 inhibited the proliferation of the 112, but not those of the 117 and 181 cells, in a dose-dependent manner. From Northern blot and immunoblot analyses, it was demonstrated that the 117 and 181 cells had undetectable levels of BMPR-II expression. The levels of luciferase activity, following adenovirus infections, was elevated in both the 117 and 181 cells, suggesting that the down-stream signaling molecules of the BMP-6 was intact in these cell lines. CONCLUSIONS: Taken together, these results demonstrate that the human RCC cell lines 117 and 181 are resistant to the growth inhibitory effects of the BMP-6 due to their decreased levels of BMPR-II expression.

Changes in the Expression of Bone Morphogenetic Protein Receptor Type IA, IB and II in Human Prostate by the Suppression of Dihydrotestosterone / 대한비뇨기과학회지

PURPOSE: To investigate whether the expression of type IA, IB and II bone morphogenetic protein receptors (hBMPRs) are affected by the suppression of dihydrotestosterone (DHT) in the prostate tissues of patients with benign prostatic hyperplasia (BPH), we determined mRNA levels and protein expression patterns of the hBMPRs in human prostate tissues. MATERIALS AND METHODS: Frozen tissues were obtained during the transurethral resection of the prostate (TURP) in BPH patients who had taken the 5alpha-reductase inhibitor (finasteride), for 3 months prior to surgery, for the reduction of the prostate volume. Tissues from patients who had not taken finasteride prior to the TURP were used as controls. Patients over 50 years old, and with a prostate volume over 50ml, were included. Semiquantitative polymerase chain reaction (PCR) and immunoblotting were used to compare the expressions of the human bone morphogenetic protein receptors (hBMPRs) between the experimental group and the controls. RESULTS: All of the BMPRs proteins were expressed in the human benign prostate tissues, with various concentrations. The semiquantitative PCR analysis showed that the mRNA level of the hBMPRs tended to decrease following 5alpha-reductase inhibition, and the magnitude of this decrease was the greatest for the hBMPR-IB. CONCLUSIONS: In the human prostate, only the expression of hBMPR-IB was significantly reduced by the suppression of DHT. Further studies on the possible role of the hBMP-hBMPR-IB complex, in the abnormal proliferation of the prostate under physiological conditions, are warranted.