OBJECTIVETo evaluate the expression of dental matrix protein-l (DMP1) in porcine oral mucosa fibroblasts (POMF) transfected by DMP1 and the influences of the transfection.

METHODSThe full length of porcine DMP1 cDNA was linked into an eukaryotic expression vector pEGFP-C1. POMF and mesenchymal stem cells (MSC) were transfected with the pEGFP-DMP1. The expression of DMP1, dental sialoprotein (DSP), amelin and ameloblastin (Ambn) gene of transfected POMF and MSC were detected by RT-PCR. The expression of DMP1 and DSP protein was examined by immunocytochemical staining. The formation ratio of mineralized nodules of transfected cells was compared with un-transfected ones after mineralized induction. The formation of mineralized nodules of three-dimensional pellet transfected cells was compared with un-transfected ones after hematoxylin and eosin staining.

RESULTSThe constructed pEGFP-DMP1 could produce 4.7 kb and 1.5 kb fragments. DMP1 gene, DSP gene and Ambn gene were expressed by POMF after transfection. Immunohistochemical staining and the quantitative analysis of protein showed that DMP1 and DSP protein was positive in transfected POMF and MSC. The formation ratio of mineralized nodules of transfected POMF and MSC was higher than that of un-transfected ones (P < 0.05).

CONCLUSIONSThe expression of porcine DMP1 in POME after gene transfection can induce the expression of tooth-development-associated gene Ambn and DSP and enhance the formation of mineralized nodules.

Animals ; Calcification, Physiologic ; Cell Differentiation ; Cells, Cultured ; Extracellular Matrix Proteins ; genetics ; metabolism ; Fibroblasts ; cytology ; metabolism ; Genetic Vectors ; Mouth Mucosa ; cytology ; Phosphoproteins ; genetics ; metabolism ; Swine ; Transfection

It is well known that estrogen can inhibit bone absorption, decrease bone turnover and preserve bone mass. Some studies indicated that the effect of estrogen on calcium and bone is relative to vitamin D system, while others also reported that this effect of estrogen is independent of vitamin D. The genomic effect of 1alpha, 25(OH)(2)D(3)is mediated by the nuclear vitamin D receptor (VDR) in a ligand-dependent manner. Hypocalcemia, hyperparathyroidism and osteomalacia are developed in VDR gene knockout mice. To determine whether the effect of estrogen on calcium and bone is dependent on VDR, this study examined the effect of exogenous estrogen on calcium and bone homeostasis in VDR gene knockout mice. Male and female wild type (WT) and VDR gene knockout heterozygous mice were mated each other and the genotyping of their offsprings were determined by PCR. At age of 21-day, WT and knockout mice were weaned and treated by one of three different regimens: (1) WT-vehicle group: the WT mice were injected with normal saline; (2) VDR KO-vehicle group: the VDR gene knockout mice were injected with normal saline; (3) VDR KO-E group: the VDR gene knockout mice were subcutaneously injected with estradiol, 0.2 mug per mouse, once daily for 1 month. The bone mineral density (BMD) of mice was measured using dual-energy X-ray absorptiometry. All mice were sacrificed at age of 50-day. Blood was taken by heart puncture under anesthesia and serum calcium was measured by autoanalyser.Tibiae were removed, fixed and embedded with the methylmethacrylate (MMA), and undecalcified sections were cut. These sections were stained for mineral with the von Kossa staining procedure and counterstained with toluidine blue. Static histomorphometric analyses were performed on those stained sections. The results showed that the serum calcium level was (2.10+/-0.37) mmol/L in the VDR KO-vehicle mice and rose to (2.80+/-0.41) mmol/L in the VDR KO-E mice although it was still lower than WT-vehicle mice [(3.10+/-0.48) mmol/L]. BMD and mineralized trabeculer volume were increased significantly in VDR KO-E group compared with that in VDR KO-vehicle group. These results suggest that exogenous estrogen can improve calcium absorption and skeletal mineralization in a VDR-independent manner.
Animals ; Bone Density ; Calcification, Physiologic ; drug effects ; Calcium ; metabolism ; Estrogens ; pharmacology ; Female ; Gene Knockout Techniques ; Homeostasis ; Mice ; Mice, Knockout ; Receptors, Calcitriol ; genetics

OBJECTIVETo investigate the expression patterns of osterix in the early stage of cranio-maxillofacial developmental in zebrafish and to prepare for a further research of osterix gene in bone and tooth development.

METHODSThe osterix templates were amplified by PCR to generate DIG labeled antisense and sense probes. Whole mount in situ hybridization was used to analyze the expression patterns of osterix in the early stage cranio-maxillofacial development of zebrafish. The expression patterns of osterix gene in mineralization progresses of cranial and maxillofacial bones were compared. The osterix gene expression in tooth development and mineralization was highlighted by alizarin red staining.

RESULTSSpecific DIG labeled probes of osterixwere synthesized successfully. The whole mount in situ hybridization showed that the osterix expression was in the intramembranous ossification at 3 days post fertilization(dpf) and 4 dpf. The specific osterix expression in tooth at 5 dpf and 6 dpf were also observed. The sense probe served as a negative control. Osterix expressed in the unmineralized early bone matrix, the tooth matrix of the primary tooth(3V(1), 5V(1)) and the first replacement tooth(4V(2)).

CONCLUSIONSOur findings showed that osterix might play roles in the process of the early mineralized bone matrix changing into the late mature mineralized bone matrix and the process of development and mineralization of tooth crown matrix.

Animals ; Calcification, Physiologic ; genetics ; Gene Expression ; Gene Expression Regulation, Developmental ; In Situ Hybridization ; Maxillofacial Development ; genetics ; Osteogenesis ; genetics ; Sp7 Transcription Factor ; Tooth ; metabolism ; Transcription Factors ; genetics ; metabolism ; Zebrafish ; Zebrafish Proteins ; genetics ; metabolism

Many studies have reported that an electromagnetic field can promote osteogenic differentiation of mesenchymal stem cells. However, experimental results have differed depending on the experimental and environmental conditions. Optimization of electromagnetic field conditions in a single, identified system can compensate for these differences. Here we demonstrated that specific electromagnetic field conditions (that is, frequency and magnetic flux density) significantly regulate osteogenic differentiation of adipose-derived stem cells (ASCs) in vitro. Before inducing osteogenic differentiation, we determined ASC stemness and confirmed that the electromagnetic field was uniform at the solenoid coil center. Then, we selected positive (30/45 Hz, 1 mT) and negative (7.5 Hz, 1 mT) osteogenic differentiation conditions by quantifying alkaline phosphate (ALP) mRNA expression. Osteogenic marker (for example, runt-related transcription factor 2) expression was higher in the 30/45 Hz condition and lower in the 7.5 Hz condition as compared with the nonstimulated group. Both positive and negative regulation of ALP activity and mineralized nodule formation supported these responses. Our data indicate that the effects of the electromagnetic fields on osteogenic differentiation differ depending on the electromagnetic field conditions. This study provides a framework for future work on controlling stem cell differentiation.
Adipose Tissue/*cytology ; Alkaline Phosphatase/metabolism ; Biological Markers/metabolism ; Bone Matrix/metabolism ; Calcification, Physiologic/genetics ; *Cell Differentiation/genetics ; Core Binding Factor Alpha 1 Subunit/metabolism ; *Electromagnetic Fields ; Humans ; *Osteogenesis/genetics ; Reproducibility of Results ; Stem Cells/*cytology/enzymology/metabolism

To investigate the effect of miR-705 on osteogenic differentiation of mouse embryo osteoblast precursor (MC3T3-E1) cells.miR-705 mimics, inhibitors and negative control were transfected into MC3T3-E1 cells. Alkaline phosphates (ALP) staining were performed and quantified after 7 days of osteogenic medium induction. The mRNA and protein expression levels of runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) were detected by real-time RT-PCR and Western blot after 14 days of osteogenic induction. Alizarin red staining was performed and quantified in MC3T3-E1 cells after 21 days of osteogenic induction.After 7 days of osteogenic induction, ALP staining showed that overexpression of miR-705 significantly reduced ALP activity, whereas knockdown of miR-705 increased ALP activity (all<0.05). Consistently, after 14 days of osteogenic induction, mRNA and protein expressions of Runx2 and OCN were suppressed by overexpression of miR-705, whereas they were promoted by knockdown of miR-705 (all<0.05). After 21 days of osteogenic induction, alizarin red staining showed that overexpression of miR-705 significantly reduced the formation of mineralized node, the opposite results were found in miR-705 knockdown group (all<0.05).miR-705 can inhibit the osteogenic differentiation of MC3T3-E1 cells.
Alkaline Phosphatase ; drug effects ; genetics ; Animals ; Calcification, Physiologic ; drug effects ; genetics ; Cell Differentiation ; drug effects ; genetics ; Core Binding Factor Alpha 1 Subunit ; drug effects ; genetics ; Down-Regulation ; drug effects ; genetics ; Fetal Stem Cells ; Mice ; MicroRNAs ; pharmacology ; Osteoblasts ; drug effects ; Osteocalcin ; drug effects ; genetics ; Osteogenesis ; drug effects ; genetics

Distraction osteogenesis is currently a standard method of bone lengthening. It is a viable method for the treatment of short extremities as well as extensive bone defects, because large amounts of bone can be regenerated in the distraction gap. echanical stimulation by distraction induces biological responses of skeletal regeneration that is accomplished by a cascade of biologic processes that may include differentiation of pluripotential tissue, angiogenesis, mineralization, and remodeling. There are complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Regenerate bone forms by three modes of ossification, which include intramembranous, enchondral, and transchondroid ossifications, although intramembraneous bone formation is the predominant mechanism of ossification. In this review we discussed the coupling between angiogenesis and mineralization, the biological and mechanical factors affecting them, the cellular and molecular events occurring during distraction osteogenesis, and the emerging modalities to accelerate regenerate bone healing and remodeling.
Animals ; Biological Markers ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 4 ; Bone Morphogenetic Proteins/genetics/metabolism ; Bone and Bones/radiography/ultrastructure ; Calcification, Physiologic/*physiology ; Collagen/metabolism ; Cytokines/metabolism ; Growth Substances/metabolism ; Humans ; Neovascularization, Physiologic/*physiology ; Osteoblasts/physiology ; *Osteogenesis, Distraction ; *Transforming Growth Factor beta

Mesenchymal stem cells (MSCs) have been identified and isolated from dental tissues, including stem cells from apical papilla, which demonstrated the ability to differentiate into dentin-forming odontoblasts. The histone demethylase KDM6B (also known as JMJD3) was shown to play a key role in promoting osteogenic commitment by removing epigenetic marks H3K27me3 from the promoters of osteogenic genes. Whether KDM6B is involved in odontogenic differentiation of dental MSCs, however, is not known. Here, we explored the role of KDM6B in dental MSC fate determination into the odontogenic lineage. Using shRNA-expressing lentivirus, we performed KDM6B knockdown in dental MSCs and observed that KDM6B depletion leads to a significant reduction in alkaline phosphate (ALP) activity and in formation of mineralized nodules assessed by Alizarin Red staining. Additionally, mRNA expression of odontogenic marker gene SP7 (osterix, OSX), as well as extracellular matrix genes BGLAP (osteoclacin, OCN) and SPP1 (osteopontin, OPN), was suppressed by KDM6B depletion. When KDM6B was overexpressed in KDM6B-knockdown MSCs, odontogenic differentiation was restored, further confirming the facilitating role of KDM6B in odontogenic commitment. Mechanistically, KDM6B was recruited to bone morphogenic protein 2 (BMP2) promoters and the subsequent removal of silencing H3K27me3 marks led to the activation of this odontogenic master transcription gene. Taken together, our results demonstrated the critical role of a histone demethylase in the epigenetic regulation of odontogenic differentiation of dental MSCs. KDM6B may present as a potential therapeutic target in the regeneration of tooth structures and the repair of craniofacial defects.
Alkaline Phosphatase ; analysis ; Bone Morphogenetic Protein 2 ; genetics ; Bone Morphogenetic Protein 4 ; genetics ; Calcification, Physiologic ; genetics ; Cell Culture Techniques ; Cell Differentiation ; genetics ; Cell Lineage ; Dental Papilla ; cytology ; Epigenesis, Genetic ; genetics ; Gene Knockdown Techniques ; Homeodomain Proteins ; genetics ; Humans ; Jumonji Domain-Containing Histone Demethylases ; genetics ; Mesenchymal Stromal Cells ; physiology ; Odontoblasts ; physiology ; Odontogenesis ; genetics ; Osteocalcin ; analysis ; Osteopontin ; analysis ; Promoter Regions, Genetic ; genetics ; RNA, Small Interfering ; genetics ; Sp7 Transcription Factor ; Transcription Factors ; analysis ; genetics ; Transcriptional Activation ; genetics

OBJECTIVETo investigated the effect of icariin and genistein on proliferation and mineralization of cultured rat osteoblasts (rat calvarial osteoblasts, ROB). And to contrast the pharmacological activity of icariin and genistein.

METHODBone cells were obtained by enzyme digestion from the segregated neonatal SD rat skull, and were cultured in MEM containing 10% FBS which was changed after three days later. Serial subcultivation was proceeded when cells covered with 90% culture dish. The final action concentration of icariin and genistein were both 1 x 10(-5) mol x L(-1). Proliferation was analyzed by MTT on 96-well plates, while differentiation was analyzed on 24-well plates. Under the induced condition, the alkaline phosphatase activity, calcium salt sediment yield and osteocalcin were measured at the 3, 6, 9, 12 d. At 12th day, ALP staining, alizarin red staining and calcified nodule count were preceded. Total RNA was isolated at 0, 6, 12, 24, 48, 72 h. The gene expression of bFGF, IGF-1, Osterix and Runx-2 was analyzed by Real-time RT-PCR.

RESULTWith the concentration of 1 x 10(-5) mol x L(-1), icariin and genistein have no significant effect on the ROB' s proliferation. The osteogenesis, ALP activity, calcium salt sediment yield and osteocalcin, calcified tubercle amount were significantly increased. And they enhanced the mRNA level of bFGF, IGF-1, Osterix and Runx-2. On the level of osteoblasts, the activity of icariin is stronger than that of genistein.

CONCLUSIONWhen the final concentration of icariin and genistein is 1 x 10(-5) mol x L(-1), they can significantly promoted ROB maturation. And on the level of osteoblasts, the activity of icariin is stronger than that of genistein.

Alkaline Phosphatase ; metabolism ; Animals ; Calcification, Physiologic ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit ; genetics ; Fibroblast Growth Factor 2 ; genetics ; Flavonoids ; pharmacology ; Genistein ; pharmacology ; Osteoblasts ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley ; Transcription Factors ; genetics

OBJECTIVETo investigate the effect of genistein on osteoblast proliferation, cellular cycle, apoptosis and differentiation of osteoblasts cultivated under hypoxia conditions.

METHODRat osteoblasts were isolated from calvarias by enzyme digestion and a hypoxic model was established by in a triple-gas incubator. Rat osteoblasts were grouped into the normoxic control group, the hypoxia control group and the hypoxia administration group which was subdivided into Ge-6 group, Ge-5 group and Ge-4 group, to which genistein was administered at doses of 1 x 10(-6), 1 x 10(-5), 1 x 10(-4) mol x L(-1). The cell survival rate, lactic dehydrogenase leakage rate, apoptosis and differentiation of osteoblasts were observed for each group at 3 h after hypoxia, and the gene expression of HIF-1alpha, Bcl-2, Caspase-3 was detected by Real time RT-PCR. Forty-eight hours after hypoxia, osteogenic differentiation markers including alkaline phosphatase activity and nodules were detected.

RESULTCompared with the hypoxia control group, the hypoxia administration group displays a significant increase in the survival rate and a decreased in LDH leakage rate, apoptosis rate and percentage of S + G2 phases. Besides, the mRNA level of HIF-1alpha and Bcl-2 were enhanced, the mRNA level of Caspase-3 was inhibited.

CONCLUSIONGenistein has an effect on protecting osteoblasts from hypoxia.

Alkaline Phosphatase ; metabolism ; Animals ; Apoptosis ; drug effects ; Calcification, Physiologic ; drug effects ; Caspase 3 ; genetics ; Cell Cycle ; drug effects ; Cell Hypoxia ; Cell Survival ; drug effects ; Cells, Cultured ; Genes, bcl-2 ; Genistein ; pharmacology ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; L-Lactate Dehydrogenase ; metabolism ; Osteoblasts ; cytology ; drug effects ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of icariin on the osteogenic differentiation of rat bone marrow stromal cells (rBMSCs).

METHODrBMSCs were cultured by adherence screening method. Icariin was supplemented into the culture at 1 x 10(-5) mol x L(-1). The osteogenic differentiation markers including alkaline phosphatase (ALP) activity, CFU-F(ALP) and mineralized bone modulus were compared between the icariin-supplemented group and the control group. Total RNA was isolated and the gene expression of bFGF, IGF-1, Osterix(OSX) and Runx-2 was investigated by RT Real-time PCR.

RESULTIcariin significantly improved ALP activity, CFU-F(ALP) amounts and mineralized modulus. It also can enhance the mRNA level of bFGF, IGF-1, Osterix and Runx-2.

CONCLUSIONIcariin enhances the osteogenic differentiation of rBMSCs significantly, which suggested that icariin has the potentiality to be a new drug of anti-osteoporosis or fracture healing.

Alkaline Phosphatase ; genetics ; metabolism ; Animals ; Bone Marrow Cells ; cytology ; drug effects ; metabolism ; Calcification, Physiologic ; drug effects ; Cell Differentiation ; drug effects ; Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; Flavonoids ; pharmacology ; Insulin-Like Growth Factor I ; genetics ; metabolism ; Male ; Osteogenesis ; drug effects ; Rats ; Rats, Wistar ; Stromal Cells ; cytology ; drug effects ; metabolism