We aimed to examine the effect of pioglitazone on transdifferentiation of preosteoblasts from rat bone marrow mesenchymal stem cells (BMSCs) into adipocytes and investigate its effect on bone metabolism. BMSCs were harvested from the femurs and tibias of a rat, then separated, purified, proliferated for 3 generations and differentiated into preosteoblasts for 5 days and 14 days respectively in the presence of osteogenic medium. Thereafter, the preosteoblasts were cultured for 21 days in the presence of adipogenic medium with and without pioglitazone (1 μg/mL). Partially-differentiated osteoblasts were identified by mineralized nodules with Alizarin red S staining. Transdifferentiated adipocytes were identified by Oil Red O staining. Reverse transcription PCR (RT-PCR) was performed to assay the expression levels of osteogenic markers Runx2 and ALP, and an adipogenic marker PPARγ. Those cells cultured for 5 days did not show mineralized nodules as detected by staining of Alizarin red S, while those cultured for 14 days showed dispersed mineralized centers in the form of brown spots, although without obvious red mineralized nodules. After adipogenic transdifferentiation for 21 days, adipose-drops were found in cells of 5CG and 5EG earlier than those of 14CG and 14EG, and the former showed much more adipocytes separately as detected by Oil Red O staining. Whatever the time was 5 days or 14 days of BMSCs osteogenic differentiation, the cells cultured with pioglitazone showed much more adipocytes than those without pioglitazone. Our experiment showed that the less time it took for BMSCs osteogenic differentiation, a stronger ability remained for BMSCs to transdifferentiate into adipocytes. The mRNA expression levels of Runx2 and ALP were decreased by 1.79 and 1.90 times respectively in 5EG (P< 0.05) as compared with 5CG, and that of PPARγ was increased by 1.31 times in 5EG (P<0.05) as compared with 5CG. The mRNA expression levels of Runx2 and ALP were decreased by 1.45 and 1.54 times respectively in 14EG (P<0.05) as compared with 14CG, and that of PPARγ was increased by 1.39 times in 14EG (P<0.05) as compared with 14CG. It was concluded that pioglitazone stimulated the transdifferentiation of BMSCs into adipocytes. These observations provided a potential mechanism of imbalance in thiazolidinedione induced bone metabolism.
Adipocytes ; drug effects ; Animals ; Cell Transdifferentiation ; drug effects ; Female ; Male ; Mesenchymal Stromal Cells ; drug effects ; Osteoblasts ; drug effects ; Osteogenesis ; drug effects ; Rats ; Rats, Sprague-Dawley ; Thiazolidinediones ; pharmacology

Animals ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Ceramics ; pharmacology ; Gene Expression Regulation ; drug effects ; Glass ; Humans ; Osteoblasts ; drug effects ; metabolism ; Osteogenesis ; drug effects

OBJECTIVETo establish the human osteoblasts culture system in vitro, observe the effects of icariin on human osteoblasts proliferation and expression of OPG protein, and to explore the mechanism of promoting bone formation about human osteoblast in icariin.

METHODSThe femoral cancellous bone pieces were obtained from the operation. The enzyme digestion method was used for culturing. The third passage of human osteoblast was taken for experiments. The cells were divided into four groups, the control group was treated with 15% NCS-DMEM-F12 (1:1), the experimental groups were respectively treated with 10(-6), 10(-8), 10(-10) mol/L icariin. The MTT method was used to observe the proliferation of human osteoblast on 1, 3, 5, 7, 9 d; in 8, 10, 12 d, western blot was used to determine the expression of OPG protein on human osteoblast.

RESULTS1) Results of MTT: the icariin promoted the proliferation of human osteoblast. There was a concentration-response relation,while with the concentration of icariin increased, the ability was more obvious. There was statistically difference between 10(-6) mol/L icariin group (0.402 +/- 0.033) and the control group (0.268 +/- 0.031) (P<0.05). In the timely research, as the time prolong, the number of human osteoblast were more. At the fifth day, the human osteoblast entered rapid growth period, and access the growth platform stage; the icariin began to promote the proliferation of human osteoblast from the fifth day, which almost maintained to the 7th day and the 9th day, and most obvious in the 9th day. There was statistically difference between 10(-6) mol/L icariin group (0.402 +/- 0.033) and the control group (0.268 +/- 0.031) at the 9th day. (The results of OPG protein expression: in the control group, the expression of OPG protein was detected at the 8th day (1.01 +/- 0.08), and reached the expression peak (1.80 +/- 0.10), there was statistically different (P<0.05). In the different days and different concentration icariin groups, the expressions of OPG protein were all inferior to the control group. While the concentration decreasing, the expression was less. There were statistically difference (P<0.05). At the day 12, there was no significant difference of OPG protein expression between the 10(-6) mol/L icariin group and the 10(-8) mol/L icariin group (P>0.05).

CONCLUSIONThe effect of icariin promoting the proliferation of human osteoblast maybe is one of the mechanisms of improving the bone formation on human osteoblast.

Animals ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Flavonoids ; pharmacology ; Gene Expression Regulation ; drug effects ; Humans ; Osteoblasts ; cytology ; drug effects ; metabolism ; Osteogenesis ; drug effects ; Osteoprotegerin ; metabolism

Searched the articles between 2000 and 2010, found out and summarized the articles with the topic on the experiment and new techniques of traditional Chinese medicine treating to osteoporosis. The preventive and therapeutic effect to osteoporosis by traditional Chinese medicine had been developed in the past 10 years. The study on standardization of experimental drugs, and the mechanism study with modern cell culture techniques should be enhanced.
Animals ; Humans ; Medicine, Chinese Traditional ; Osteoblasts ; cytology ; drug effects ; Osteoclasts ; cytology ; drug effects ; Osteoporosis ; drug therapy ; Tissue Engineering

OBJECTIVETo study the effect of genistein on the proliferation, differentiation and apoptosis of the osteoblasts in vitro.

METHODSThe primary osteoblasts (OBs) were obtained from the rat calvaria and the cell line of osteosarcoma-UMR-106 served as control. The cells in the experiment group were grown in 10% (volume fraction) fetal calf serum (FCS) + alphaMEM + various concentrations of genistein. The control groups were grown in 10% FCS + alphaMEM. The growth of OBs was assessed by flow cytometry and MTT method. The differentiation of OBs was examined by the alkaline phosphatase (ALP) activity.

RESULTSFlow cytometry analysis and MTT showed that genistein could prompt primary OB from stage G(0) (G(1)) to stage S, G(2) or M. By contrast, genistein had no effect on the cell cycle of UMR-106, but could induce its apoptosis. Additionally, the results of ALP activity showed that genistein stimulated the differentiation of primary OB.

CONCLUSIONSGenistein can stimulate the proliferation and differentiation of the primary osteoblasts in some degree, and induce the apoptosis of osteosarcoma cells.

Animals ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cells, Cultured ; Genistein ; pharmacology ; Osteoblasts ; cytology ; drug effects ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the effects of dexamethasone on proliferation, differentiation and apoptosis of adult human osteoblasts in vitro.

METHODSIliac trabecular bone specimens were obtained from adult patients undergoing necessary surgery. After the bone pieces were digested with collagenase-trypsin, osteoblasts were released and incubated at 37 degrees C in a relative humidity of 95% and 5% CO2. Then, the cells were purified, and their passages were given DMEM-F12 and fetal bovine serum medium. Subsequently, 10(-8) mol/L dexamethasone was added into the culture medium to incubate the osteoblasts for three days, and the cells from control groups were incubated without any drugs. All cells were observed continually with phase contrast microscope and transmission electron microscope. Finally, apoptosis was detected by the use of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and biochemical indices, alkaline phosphatase (ALP) and osteocalcin (OCN) were used to determine the effects of dexamethasone on proliferation, differentiation and apoptosis of adult osteoblasts in vitro.

RESULTSIn the adult osteoblasts obtained by collagenase-trypsin digestion, it achieved high survival, stable biochemical indices and excellent purification. Under the condition of dexamethasone 10(-8) mol/L and osteoblasts 10,000/ml, there was significant promotion of ALP and OCN secretion without cell apoptosis.

CONCLUSIONSDexamethasone has a significant effect on the proliferation and differentiation of adult osteoblasts in vitro without apoptosis, and dexamethasone at the suggested concentration can be used as positive control in drug studies for osteoporosis treatment.

Adult ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Cells, Cultured ; Dexamethasone ; pharmacology ; Humans ; In Situ Nick-End Labeling ; Osteoblasts ; cytology ; drug effects

Clinically, there has been so far no effective way to repair the bone-missing of large extent due to gash, infection and removal of tumor. The solution of this problem can be assisted by the addition of bioactive substances to substrate materials, because the growth of peripheral tissue and the fiber tissue growing the materials can be induced to the direction of bone-tissue by these biomaterials with bioactive peptides. The peptide Arg-Gly-Asp is the point between the integrin which comes from membrane and the ligand. In certain cases, the artificially synthesized RGD can be competitively combined with the integrin on cell surface, and outer-cell information is transmitted into cells, which will cause a series of physiological changes in cells. Presently, it is reported that the RGD has the ability to induce the growth of osteoblasts, restrain the adhesion between osteoclasts and substrates. This paper reviews and introduces the progress made with the work of RGD-inducing bone regeneration.
Biocompatible Materials ; Bone Regeneration ; drug effects ; physiology ; Cell Adhesion ; drug effects ; Oligopeptides ; administration & dosage ; chemistry ; pharmacology ; Osteoblasts ; drug effects ; physiology ; Osteoclasts ; drug effects ; physiology ; Tissue Engineering ; methods

The present study aims to investigate the lignan constituents from Sambucus williamsii and their proliferation effects on osteoblast-like UMR106 cells. Seven compounds were isolated and purified by macroporous resin D101, silica gel, Sephadex LH-20, Toyopearl HW-40, ODS column chromatographies and Preparative HPLC(C-18). Their structures were elucidated by spectroscopic methods as threo-guaiacylglycerol-beta-0-4'-conifery ether (1), lirioresinol A (2), 1-hydroxypinoresinol (3), 5-methoxybalanophonin (4), balanophonin (5), 5-methoxy-trans-dihydrodehydrodiconiferyl alcohol (6), and p-hydroxybenzaldehyde (7). Compounds 3-7 were obtained from this genus for the first time. The proliferation effects of all isolated compounds on osteoblast-like UMR106 cells were determined. Compounds 1-7 (1 x 10(-12)-1 x 10(-7) mol x L(-1)) increased UMR106 cell proliferation to some extent.
Cell Line ; Cell Proliferation ; drug effects ; Lignans ; isolation & purification ; pharmacology ; Osteoblasts ; cytology ; drug effects ; Plant Stems ; chemistry ; Sambucus ; chemistry

BACKGROUNDSurface modification by ion implantation-deposition is well established in materials science and can be an effective way to improve biocompatibility. The aim of this study is to evaluate the chemical composition of a modified titanium (Ti) surface after zinc (Zn) ion implantation and deposition and examine the effect of the modification on the formation of cellular focal adhesion plaques in vitro.

METHODScp-Ti discs were modified with Zn ion implantation and deposition via PIIID. The chemical composition of the surface modification was characterized by X-ray photoelectron spectroscopy (XPS). The formation of focal adhesion plaques on the modified Ti was investigated with human osteoblast-like MG-63 cells that were seeded onto the Ti surfaces and quantified by morphometric analysis under a confocal microscope.

RESULTSXPS data revealed that the modified Zn-Ti surface consisted of Ti, oxygen, Zn, and carbon. In addition, Gaussian fitting of the spectra indicated that the modified surface contained titanium dioxide and zinc oxide. After 6 hours of MG-63 cell culture, there were significantly more focal adhesion plaques on the modified surfaces than observed on the nonmodified Ti (P < 0.05).

CONCLUSIONZn ion implantation and deposition greatly improved the biocompatibility of Ti for the growth of MG-63 cells.

Cell Adhesion ; drug effects ; Cell Line ; Humans ; Osteoblasts ; cytology ; drug effects ; Photoelectron Spectroscopy ; Titanium ; pharmacology ; Zinc Oxide ; pharmacology

OBJECTIVETo investigate the expression of immune-related genes during osteogenesis stimulated by simvastatin.

METHODSAfter treated with simvastatin, the expression of immune-related genes of mouse osteoblast was examined with gene chip (BiostarM-140s).

RESULTSThere were 16 differently expressed genes related to immune function, with nine down-regulated genes and seven up-regulated genes.

CONCLUSIONSAfter treated with simvastatin, expression of inflammation related genes is down-regulated and inflammation inhibitor genes is up-regulated in mouse osteoblasts.

Animals ; Down-Regulation ; Gene Expression Profiling ; Gene Expression Regulation ; Mice ; Osteoblasts ; drug effects ; immunology ; Osteogenesis ; drug effects ; Simvastatin ; pharmacology