Osteoclast, a huge coenocytes,originates from mononuclear macrophages or monocytic series hematopoietic precursor cell, plays an important role in the progree of bone resorption. Formation and abnormal activity of osteoclast may cause osteoprosis, rheumatoid arthritis and aseptic loosening after arthroplasty. Therefore, osteoclast is the target for treating these disease. At present, a lot of study on formation of osteoclast were reported, but the study on how to identify and degradation of bone tissue is not yet reported. Bone mineral are seen as important component of identifing osteoclast, and the research suggested that bone matrix is not the essential ingredients of activiting osteoclast, petri dish covered by vitronectin also can make osteoclast occure certain form of bone resorption, vitronectin plays an significant role in activiting osteoclast. Otherwise, the research found that swallowing and secretion of bone matrix degradation products is benefit for differentiation of osteoclast and maintain of function, and this may be therapeutic target for treatment of musculoskeletal disorders.
Animals ; Bone Matrix ; metabolism ; Bone Resorption ; Humans ; Osteoclasts ; physiology

OBJECTIVETo discuss the function of MMP-9, MMP-2 in the remodeling bone tissue around implant during unloaded period.

METHODSAt the anterior of the maxilla and mandibular of the Beagle dog, implants were placed at different periods, so the implant specimens of different periods were obtained after dogs were killed. The implant specimens were removed, fixed in 4% paraformaldehyde for 24 hours at 4 degrees C, decalcified with 10% EDTA at pH 7.2, embedded in paraffin wax and sectioned. The observation of the expression changes of the MMP-2, MMP-9 in the milien bone tissue of the implant at different periods were taken by immunohistochemical staining.

RESULTSMatrix metalloprotainase (MMP-9) was mostly expressed at the peripheral cytoplasmic of osteoclast, macrophage, lining cell and fibroblast. MMP-2 was mostly expressed at the peripheral cytoplasmic of osteoblast, fibroblast, some osteoclast also expressed this enzyme.

CONCLUSIONMMP-2 and MMP -9 have an important function at the injured bone absorption, healing and bone remodeling after dental implant placement.

Animals ; Bone Remodeling ; Dental Implantation, Endosseous ; Dental Implants ; Dogs ; Mandible ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Maxilla

BACKGROUNDSerum osteoprotegerin (OPG) and matrix metalloproteinase-2 (MMP-2) have been shown to play a role in bone metabolism by degrading the bone matrix. The present study was undertaken to compare OPG and MMP-2 with bone mineral density and three markers (alkaline phosphatase (AKP), calcium and phosphorus) in postmenopausal women in Wuhan.

METHODSSerum OPG, MMP-2, and AKP of 78 Chinese postmenopausal women aged 48 to 65 were measured using enzyme-linked immunosorbent assay (ELISA). Bone mineral density was measured with dual energy X-ray absorptiometry (DEXA), and serum calcium and phosphorus were measured by auto biochemical analysis.

RESULTSSerum OPG and MMP-2 concentrations were significantly higher in postmenopausal women with osteoporosis ((127.6 +/- 6.3) ng/L; (1388 +/- 121) microg/L)) than those in age-matched normal controls ((72.3 +/- 2.4) ng/L; (1126 +/- 141) microg/L, P < 0.01). Negative relationships were found between serum OPG, MMP-2 levels and bone mineral density in osteoporotic women. Adjusted by age and body mass index (BMI), the correlation of MMP-2 with bone mineral density of the neck of the femur disappeared. In osteoporotic women, negative correlations between OPG, MMP-2 levels and serum calcium were found (r = -0.216; r = -0.269, P < 0.05), but positive correlations between OPG and serum AKP, serum phosphorus (r = 0.235; r = 0.124, P < 0.05).

CONCLUSIONSSignificant correlations exist between serum OPG, MMP-2 levels and bone metabolism in high bone turnover of postmenopausal osteoporotic women. The concentrations of serum OPG and MMP-2 increase possibly as a concomitant event in the high bone turnover state, such as postmenopausal osteoporosis. Therefore serum OPG and MMP-2 could be used as indicators for the bone metabolism in postmenopausal osteoporotic women.

Aged ; Bone Density ; Bone and Bones ; metabolism ; Calcium ; blood ; Female ; Humans ; Matrix Metalloproteinase 2 ; blood ; Middle Aged ; Osteoprotegerin ; blood ; Postmenopause ; metabolism

Various biological approaches to the promotion of periodontal regeneration have been used. These can be divided into the use of growth and differentiation factors, application of extracellular matrix proteins and attachment factors and use of mediators of bone metabolism. The purpose of this study was to evaluate the effect of enamel matrix protein and platelet-rich plasma on the treatment of intrabony defect, with bovine-derived bone powder in humans by digital subtraction radiography. 12 teeth(experimental I group) were treated with enamel matrix protein combined with bovine-derived bone powder and 12 teeth(experimental II group) were treated with platelet-rich plasma combined with bovine-derived bone powder. The change of bone density was assessed by digital subtraction radiography in this study. The change of mineral content was assessed in the method that two radiographs were put into computer program to be overlapped and the previous image was subtracted by the later one. Both groups were statistically analyzed by Wilcoxon signed Ranks Test and Mann-whitney Test using SPSS program for windows(5% significance level). The results were as follows: 1. The radiolucency in 3 months after surgery was significantly increased than 1 month after surgery in both groups(experimental I and II groups)(p<0.05). 2. The radiopacity in 6 months after surgery was significantly increased than 3 months after surgery in both groups(experimental I and II groups)(p<0.05). 3. In experimental I group, there was no significant difference between 1 month and 6 months after surgery. 4. In experimental II group, the radiopacity in 6 months after surgery was significantly increased than 1 month after surgery(p<0.05). 5. There was no significant difference between experimental I and II group at 1 month and 3 months after surgery, but the radiopacity in experimental II group was significantly increased at 6 months after surgery(p<0.05). In conclusion, platelet-rich plasma can enhance bone density than enamel matrix protein until 6 months after surgery.
Bone Density ; Dental Enamel* ; Extracellular Matrix Proteins ; Heterografts* ; Humans* ; Metabolism ; Platelet-Rich Plasma* ; Radiography* ; Regeneration

The physiological reconstruction of bone is strictly dependent on bone resorption. Bone resorption is believed to be a complicated molecular reaction process that occurs in the microcircumstance of bone tissue. A lot of enzymes and factors take part in this process, yet there are not enough data with reference to the activation of osteoclast, resorption of bone matrix, regulation of bone resorption. In this paper we review the importance of matrix metalloproteinases (MMPs) in transfer of osteoclast and degradation of bone matrix, and the function of receptor activator of NF-kappaB-ligand (RANKL) and osteoprotegerin (OPG) in regulation of bone resorption.
Bone Resorption ; Humans ; Matrix Metalloproteinases ; metabolism ; Osteoclasts ; physiology ; Osteoprotegerin ; physiology ; RANK Ligand ; physiology

Canine mesenchymal cells (MSCs) derived from Wharton's jelly were co-cultured, then supplemented or not supplemented with platelet rich plasma (PRP) and demineralized bone matrix (DBM) to verify osteogenic differentiation. Osteoblastic differentiation followed by mineralized bone matrix production was found to be significantly higher (p < 0.05) when MSCs were associated with PRP/DBM in culture after 14-21-days of induction. Osteopontin and osteocalcin gene expression were significantly superior (p < 0.05) under the same culture conditions after 21 days of observation. In conclusion, addition of PRP to DBM co-cultured with MSCs successfully induced osteogenesis in vitro.
Animals ; Bone Demineralization Technique/veterinary ; Bone Matrix/*metabolism ; Cell Differentiation ; Cells, Cultured ; Coculture Techniques/veterinary ; Dogs ; Mesenchymal Stromal Cells/*metabolism ; *Osteogenesis ; Platelet-Rich Plasma/*metabolism ; Umbilical Cord/metabolism

OBJECTIVETo study the expression of bone matrix protein (BMP) induced by bovine bone morphogenetic proteins (BMPs) in vitro.

METHODSType I collagen, osteopontin (OPN), osteonectin (ON), osteocalcin (OC), and bone sialoprotein (BSP) were detected by immunohistochemistry in C2C12 cultured from day 1 to day 28.

RESULTSThe signaling of bone matrix protein expression became weaker except for type I collagen, OC and BSP after 5 days. Fourteen days after culture, the positive signaling of type I collagen, OPN, ON, OC, and BSP was gradually declined, and could be detected significantly as compared with that of the negative control on day 28. BMP assay showed that the alkaline phosphatase (ALP) activity was higher in C2C12 culture than in the control during the 14-day culture. Also, total protein and DNA significantly increased during the 14-day culture. High levels of ALP were seen in preosteoblasts and osteoblasts in vivo and in differentiating osteoblasts in vitro. ALP was well recognized as a marker reflecting osteoblastic activity.

CONCLUSIONNative bovine BMP induces conversion of myoblasts into osteoblasts, produces type I collagen, and plays significantly role in osteoinduction and bone matrix mineralization of C2C12 in vitro.

Alkaline Phosphatase ; metabolism ; Animals ; Bone Matrix ; metabolism ; Bone Morphogenetic Proteins ; pharmacology ; Cattle ; Cell Line ; DNA ; metabolism ; Gene Expression Regulation ; physiology ; Mice ; Osteoblasts ; drug effects ; metabolism

Wnt/β-catenin signaling plays a critical role in the achievement of peak bone mass, affecting the commitment of mesenchymal progenitors to the osteoblast lineage and the anabolic capacity of osteoblasts depositing bone matrix. Recent studies suggest that this evolutionarily-conserved, developmental pathway exerts its anabolic effects in part by coordinating osteoblast activity with intermediary metabolism. These findings are compatible with the cloning of the gene encoding the low-density lipoprotein related receptor-5 (LRP5) Wnt co-receptor from a diabetes-susceptibility locus and the now well-established linkage between Wnt signaling and metabolism. In this article, we provide an overview of the role of Wnt signaling in whole-body metabolism and review the literature regarding the impact of Wnt signaling on the osteoblast's utilization of three different energy sources: fatty acids, glucose, and glutamine. Special attention is devoted to the net effect of nutrient utilization and the mode of regulation by Wnt signaling. Mechanistic studies indicate that the utilization of each substrate is governed by a unique mechanism of control with β-catenin-dependent signaling regulating fatty acid β-oxidation, while glucose and glutamine utilization are β-catenin-independent and downstream of mammalian target of rapamycin complex 2 (mTORC2) and mammalian target of rapamycin complex 1 (mTORC1) activation, respectively. The emergence of these data has provided a new context for the mechanisms by which Wnt signaling influences bone development.
Anabolic Agents ; beta Catenin ; Bone Development ; Bone Matrix ; Clone Cells ; Cloning, Organism ; Fatty Acids ; Glucose ; Glutamine ; Lipoproteins ; Metabolism* ; Osteoblasts* ; Sirolimus

OBJECTIVE: To explore the effect of bone morphogenetic protein-2 (BMP-2 ) on the expression of membrane Type 1-matrix metalloproteinase (MT1-MMP) and the activation of matrix metalloproteinase-2 (MMP-2) in human A549 lung carcinoma cells. METHODS: Western blot was used to analyse the expression of MT1-MMP protein levels in A549 cells. Enzyme-linked immunosorbentassay was used to show the actions of BMP-2 on the activation of MMP-2 in A549 cells. RESULTS: Treatment with BMP-2 in A549 cells caused a dose- and time-dependent increase in the expression of MT1-MMP protein. BMP-2 dose-dependently activated MMP-2 in A549 cells. CONCLUSION BMP-2 might promote MT1-MMP expression and MMP-2 activation in lung carcinoma cells, which can lead to the increase of extracellular matrix followed by acceleration of tumor cell migration and invasion. It is probably another key mechanism of BMP-2 upregulated lung carcinoma cell migration.
Bone Morphogenetic Protein 2 ; pharmacology ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Matrix Metalloproteinase 1 ; biosynthesis ; Matrix Metalloproteinase 2 ; metabolism ; Neoplasm Invasiveness ; Tumor Cells, Cultured

Collagen, which widely exists in skin, bone, muscle and other tissues, is a major structural protein in mammalian extracellular matrix. It participates in cell proliferation, differentiation, migration and signal transmission, plays an important role in tissue support and repair and exerts a protective effect. Collagen is widely used in tissue engineering, clinical medicine, food industry, packaging materials, cosmetics and medical beauty due to its good biological characteristics. This paper reviews the biological characteristics of collagen and its application in bioengineering research and development in recent years. Finally, we prospect the future application of collagen as a biomimetic material.
Animals ; Collagen/analysis* ; Tissue Engineering/methods* ; Extracellular Matrix/metabolism* ; Biomimetic Materials/chemistry* ; Bone and Bones ; Tissue Scaffolds ; Mammals/metabolism*