Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Publication year range
2.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 43(3): 367-72, 2012 May.
Article in Chinese | MEDLINE | ID: mdl-22812239

ABSTRACT

OBJECTIVE: To investigate the effect of sinusoidal electricity magnetic fields (SEMFs) on the proliferation and differentiation of osteoblasts in vitro. METHODS: Calvarial osteoblasts of newborn rats were isolated by enzyme digestion and randomly divided into 3 groups after subculture. Two groups of cells were exposed to 50 Hz 1.8 mT SEMFs for 30 min/d in parallel and vertical, respectively. Those without SEMFs exposure served as control. The cells were observed under the contrast phase microscope each day. After 48 h, cell proliferation was assayed by MTT method. The alkaline phasphatase (ALP) activities and calcium contents were measured after 3, 6, 9, and 12 days. The ALP positive colonies were histochemically stained after 10 days and the calcified nodules were stained by Alizarin Bordeaux after 12 days. Expressions of ALP, bone morphogenetic protein-2 (BMP-2) and Osterix (OSX) mRNA were measured at 0 h, 24 h, 48 h and 96 h. RESULTS: The cells exposed to the SEMFs were arranged in spiral appearance after 3 days. Compared with control, SEMFs inhibited cell proliferation (P < 0.01 or P < 0.05), but enhanced the maturation and mineralization of the osteoblasts. The results showed that SEMFs improved ALP activities, promoted calcium contents, increased calcified nodulues numbers, boosted expressions of ALP, BMP-2 and OSX mRNA. SEMFs with magnetic lines of force in parallel has stronger activities than those in vertical. CONCLUSION: The SEMFs at 1.8 mT and 50 Hz inhibit the proliferation of osteoblasts, but enhance the maturation and mineralization of osteoblasts.


Subject(s)
Cell Differentiation/radiation effects , Cell Proliferation/radiation effects , Electromagnetic Fields , Osteoblasts/cytology , Alkaline Phosphatase/genetics , Alkaline Phosphatase/metabolism , Animals , Animals, Newborn , Bone Morphogenetic Protein 2/genetics , Bone Morphogenetic Protein 2/metabolism , Cells, Cultured , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Skull/cytology , Transcription Factors/genetics , Transcription Factors/metabolism
3.
Yao Xue Xue Bao ; 47(2): 174-9, 2012 Feb.
Article in Chinese | MEDLINE | ID: mdl-22512027

ABSTRACT

This study is to investigate the effect of osthol on osteoclasts' activity, bone resorption as well as apoptosis in vitro, and explore the mechanism of osthol in preventing osteoporosis. Osteoclasts were separated from long-limb bones of new born rabbits, cultured in 24-well plate with glass slices and bone slices, and treated by 1 x 10(-5) mol x L(-1) osthol. Osteoclasts were identified by observing live cells with phase contrast microscope, HE staining, TRAP staining and toluidine blue staining of bone resorption pits. The numbers of bone resorption pits were counted as well as the surface area of bone resorption on bone slice. Osteoclasts were stained with acridine orange to detect the cell apoptosis. The ratio of apoptotic osteoclasts was observed under fluorescence microscope. The gene expression of RANKL, OPG, TRAP and p-JNK1/2 protein expression were examined using real time PCR and Western blotting, respectively. Comparing with the control group without osthol, the rates of apoptotic osteoclasts increased obviously and the number and area of bone resorption pits decreased evidently with 1 x 10(-5) mol x L(-1) osthol. There is significant difference between control group and experiment group treated by 1 x 10(-5) mol x L(-1) osthol. Therefore, the osthol through RANK+RANKL/TRAF6/Mkk/JNK signal pathway inhibits the osteoclasts activity, enhances osteoclasts apoptotic and inhibits the bone resorption.


Subject(s)
Apoptosis/drug effects , Bone Resorption , Coumarins/pharmacology , Osteoclasts/pathology , Acid Phosphatase/metabolism , Animals , Cells, Cultured , Cnidium/chemistry , Coumarins/isolation & purification , Gene Expression , Isoenzymes/metabolism , Mitogen-Activated Protein Kinase 8/metabolism , Mitogen-Activated Protein Kinase 9/metabolism , Osteoclasts/metabolism , Osteoprotegerin/metabolism , Phosphorylation , Plants, Medicinal/chemistry , RANK Ligand/metabolism , Rabbits , Seeds/chemistry , Signal Transduction , Tartrate-Resistant Acid Phosphatase
4.
Zhong Yao Cai ; 34(6): 917-22, 2011 Jun.
Article in Chinese | MEDLINE | ID: mdl-22017007

ABSTRACT

OBJECTIVE: To investigate the effects of icariin on the proliferation, differentiation and maturation of rat calvarial osteoblasts (ROB). METHODS: Segregated neonatal SD rat skull,enzyme digestion to obtain ROB. The culture medium was replaced every three days. Serial subcultivation proceeded when cells covered with 80% culture dish. Icariin was added into the culture at 1 x 10(-4), 1 x 10(-5), 1 x 10(-6), 1 x 10(-7) mol/L respectively. MTT method was adopted in proliferation analysis. The activity of ALP was assayed after 9 days' induced. Optimal concentration icariin was added into the medium, then the osteogenic differentiation markers including mineralized bone nodules, CFU-F(ALP) were compared between the icariin-added group and the control. Total RNA was isolated and the gene expressions of Runx-2 and Osterix were investigated by Real Time RT-PCR. Total protein was also isolated and the secretion of collagen I was examined by Western-blot. RESULTS: The ROB proliferation was inhibited by icariin in a dose-dependent manner. But it evidently led to osteogenic process and maturation. 1 x 10(-5) mol/L was the best concentration. Icariin improved the secretion of collagen I, CFU-F(ALP) amounts and mineralized nodules significantly. It also enhanced the mRNA level of Runx-2 and Osterix. CONCLUSION: The icariin with final concentration of 1 x 10(-5) mol/L can enhance the osteogenic differentiation and maturation of ROB significantly, suggesting that icariin has the activity of inducing bone formation, it has the potential to be developed into a new drug of anti-osteoporosis.


Subject(s)
Cell Differentiation/drug effects , Drugs, Chinese Herbal/pharmacology , Flavonoids/pharmacology , Osteoblasts/drug effects , Alkaline Phosphatase/metabolism , Animals , Calcification, Physiologic/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Collagen Type I/biosynthesis , Collagen Type I/genetics , Core Binding Factor Alpha 1 Subunit/genetics , Core Binding Factor Alpha 1 Subunit/metabolism , Dose-Response Relationship, Drug , Drugs, Chinese Herbal/administration & dosage , Flavonoids/administration & dosage , Osteoblasts/cytology , Osteoblasts/physiology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Skull/cytology , Staining and Labeling
5.
Bone ; 49(4): 753-61, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21726678

ABSTRACT

Electromagnetic fields (EMFs) have been used clinically to slow down osteoporosis and promote fracture healing for many years. However, the underlying action mechanisms and optimal parameters of the EMF applications are unclear. In this study, we investigated the effects of treatment for different durations with 50 Hz sinusoidal electromagnetic fields (SEMFs) at different intensities on proliferation, differentiation and mineralization potentials of rat osteoblasts. Osteoblasts isolated from neonatal rats were treated with SEMFs (50 Hz at 0.9 mT-4.8 mT, 0.3 mT interval, 30 min/day up to 15 days). Compared to untreated control, SEMFs inhibited osteoblast proliferation (after 3 days' treatment) but increased alkaline phosphatase (ALP) activity (after treatment for 9 days) from 0.9 mT to 1.8 mT, declined from 1.8 mT until 3.0 mT, and then increased again from 3.0 mT to 3.6 mT and decreased once again from 3.6 mT to 4.8 mT. Numbers of colonies stained positive for ALP after 8 days and mineralized nodules stained by Alizarin red after 10 days showed the same bimodal tendency as with the ALP activity, with two peaks at 1.8 mT and 3.6 mT. SEMFs also bimodally increased Runx-2, Col1α2 and Bmp-2 mRNA expression levels in osteoblasts at 12, 24 and 96 h after exposure. The results indicated that while exposure to 50 Hz SEMFs inhibits the osteoblast proliferation, it significantly promotes differentiation and mineralization potentials of osteoblasts in an intensity-dependent manner with peak activity at 1.8 mT and 3.6 mT.


Subject(s)
Cell Differentiation , Electromagnetic Fields , Osteoblasts/cytology , Osteoblasts/metabolism , Alkaline Phosphatase/metabolism , Animals , Calcification, Physiologic/genetics , Cell Differentiation/genetics , Cell Proliferation , Cell Shape , Electrophoresis, Agar Gel , Gene Expression Regulation , Osteoblasts/enzymology , Osteogenesis/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Reverse Transcriptase Polymerase Chain Reaction
SELECTION OF CITATIONS
SEARCH DETAIL
...