OBJECTIVE: To investigate the effect of low-frequency pulsed electromagnetic fields (PEMF) on the maturation and mineralization of rat cranial osteoblasts and its relation to IGF-1R/NO signaling pathway. METHODS: The rat osteoblasts were isolated and cultured and randomly divided into blank control group, PEMF group, GSK group (IGF-1R blocker) and PEMF+GSK group. The cells were treated with 50 Hz 0.6 mT PEMF for 1.5 h/d. After 3 d of PEMF treatment, the expressions of protein kinase (AKT), inducible nitric oxide synthase (iNOS) and cGMP-dependent protein kinase (PKG) were detected by Western blotting; on 6 d of PEMF treatment alkaline phosphatase (ALP) activity was determined; on 12 d of PEMF treatment the calcification nodule formation was demonstrated by Alizarin red staining. RESULTS: NO level was significantly increased in rat osteoblasts treated with 50 Hz 0.6 mT PEMF for 1.5 h/d. Western blot analysis showed that the expressions of AKT, iNOS and PKG protein in PEMF group were higher than those in the control group (all <0.01); the ALP activity was increased(<0.05), and the PEMF group had the largest area of Alizarin red staining (<0.01). The expressions of AKT, iNOS and PKG protein in GSK group were lower than those in the control group; the ALP activity was decreased (<0.05), and the GSK group had the least area of Alizarin red staining (<0.01). The expressions of AKT, iNOS, PKG protein, the ALP activity and the area of Alizarin red staining in PEMF+GSK group were between PEMF group and GSK group. CONCLUSIONS PEMF may enhance the maturation and mineralization of rat cranial osteoblasts through IGF-1R/NO signaling pathway.
Animals ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Electromagnetic Fields ; Nitric Oxide ; metabolism ; Osteoblasts ; radiation effects ; Rats ; Receptor, IGF Type 1 ; metabolism ; Signal Transduction ; radiation effects

The present study was aimed to investigate the effects and mechanisms of electro-acupuncture (EA) on proliferation and differentiation of neural stem cells in the hippocampus of C57 mice exposed to different doses of X-ray radiation. Thirty-day-old C57BL/6J mice were randomly divided into control, irradiation, and EA groups. The control group was not treated with irradiation. The irradiation groups were exposed to different doses of X-ray (4, 8 or 16 Gy) for 10 min. The EA groups were electro-acupunctured at Baihui, Fengfu and bilateral Shenyu for 3 courses of treatment after X-ray radiation. Immunohistochemistry was used to evaluate proliferation and differentiation of the hippocampal neural stem cell. RT-PCR and Western blot were used to detect mRNA and protein expressions of Notch1 and Mash1 in the hippocampus, respectively. The results showed that, compared with the control group, the numbers of BrdU positive cells (4, 8 Gy subgroup) and BrdU/NeuN double-labeling positive cells (3 dose subgroups) were decreased significantly in the irradiation group, but the above changes could be reversed by EA. Compared with the control group, the number of BrdU/GFAP double-labeling positive cells in each dose subgroup of irradiation group was decreased significantly, while EA could reverse the change of 4 and 8 Gy dose subgroups. In addition, compared with the control group, the expression levels of Notch1 mRNA and protein in hippocampus were up-regulated, and the expression levels of Mash1 mRNA and protein were significantly decreased in each dose subgroup of irradiation group. Compared with irradiation group, the expression levels of Notch1 mRNA and protein in hippocampus of EA group were decreased significantly in each dose subgroup, and the expression levels of Mash1 mRNA and protein were increased significantly in 4 and 8 Gy subgroups. These results suggest that irradiation affects the proliferation and differentiation of neural stem cells in hippocampus of mice, whereas EA may significantly increase the proliferation and differentiation of hippocampal neural stem cells via the regulation of Notch signaling pathway.
Animals ; Basic Helix-Loop-Helix Transcription Factors ; metabolism ; Cell Differentiation ; Cell Proliferation ; Electroacupuncture ; Hippocampus ; cytology ; radiation effects ; Mice, Inbred C57BL ; Neural Stem Cells ; cytology ; radiation effects ; Random Allocation ; Receptor, Notch1 ; metabolism ; X-Rays ; adverse effects

OBJECTIVE: To explore the effects of low level laser irradiation (LLLI) on the osteogenic capacity of three-dimensional (3D) structure by 3D bio-printing construct used human adipose-derived stem cells (hASCs) as seed cells. METHODS: Using hASCs as seed cells, we prepared sodium alginate/gelatin/hASCs 3D bio-printing construct, and divided them into four groups: PM (proliferative medium), PM+LLLI, OM (osteogenic medium) and OM+LLLI, and the total doses of LLLI was 4 J/cm². Immunofluorescence microscopy was used to observe the viability of the cells, and analyze the expression of the osteogenesis-related protein Runt-related transcription factor 2 (Runx2) and osteocalcin (OCN). RESULTS: The 3D constructs obtained by printing were examined by microscope. The sizes of these 3D constructs were 10 mm×10 mm×1.5 mm. The wall thickness of the printed gelatin mold was approximately 1 mm, and the pores were round and had a diameter of about 700 μm. The cell viability of sodium alginate/gelatin/hASCs 3D bio-printing construct was high, and the difference among the four groups was not significant. On day 7, the expression of OCN from high to low was group OM+LLLI, PM+LLLI, OM and PM. There were significant differences among these groups (P<0.01), but there was no significant difference between group PM+LLLI and OM. On day 14, the expression of OCN in each group was higher than that on day 7, and there was no significant difference between group OM+LLLI and OM. The expression of Runx2 in group OM+LLLI was more than 90%, significantly higher than that in group OM (P<0.01). But the expression of Runx2 in group PM+LLLI and OM+LLLI were significantly lower than that in the non-irradiated groups. The expression of osteogenesis-related protein Runx2 and OCN were higher in OM groups than in PM groups. Furthermore, the irradiated groups were significantly higher than the non-irradiated groups. CONCLUSION LLLI does not affect the cell viability of sodium alginate/gelatin/hASCs 3D bio-printing construct, and may promote the osteogenic differentiation of hASCs.
Adipocytes/radiation effects* ; Alginates ; Cell Differentiation ; Cell Proliferation ; Gelatin ; Humans ; Lasers ; Osteogenesis ; Printing, Three-Dimensional ; Stem Cells/radiation effects*

Objective: To compare the effects of 50 Hz 1.8 mT sinusoidal magnetic field (SEMF) and 50 Hz 0.6 mT pulsed electromagnetic field(PEMF) on the maturation and mineralization of rat calvaria osteoblasts. Methods: Primary cultured rat calvarial osteoblasts were divided into 3 groups:blank control group, SEMF group and PEMF group. The rats in SEMT and PEMT groups were treated with 50 Hz 1.8 mT SEMF or 50 Hz 0.6 mT PEMF for 90 min/d, respectively. Western blotting and Real-time RT-PCR were used to detect the protein and mRNA expressions of Collagen-1, bone morphogenetic protein 2 (BMP-2), osterix (OSX) and Runt-associated transcription factor 2(Runx-2). The alkaline phosphatase(ALP) activity was detected by ALP test kits at d6 and d9 after treatment, and by ALP staining using azo coupling at d10 after treatment. The formation of calcium nodules was observed by alizarin red staining. Results: Compared with blank control group, the protein and mRNA expressions of Collagen-1, BMP-2, OSX and Runx-2 in SEMT and PEMT groups were significantly increased (P <0.01 or P <0.05); while the mRNA expressions of Collagen-1 and BMP-2 in PEMF group were significantly higher than those in SEMF group. After 6 days treatment, the activity of ALP in PEMF group was significantly higher than that in blank control group (P<0.05), while such difference was not observed in SEMF group (P0.05); after 9 days treatment, the activities of ALP in both PEMF and SEMP groups were significantly higher than that in blank control group (all P<0.05), but the difference between PEMF and SEMF groups was not significant (P0.05). After 10 days treatment, ALP staining was increased in both PEMF and SEMF groups compared with that in blank control group (all P<0.01), and the stained area was bigger in PEMF group than that in SEMF group (P<0.05). After 12 days treatment, calcium nodules were increased in PEMF and SEMF groups compared with that in blank control group (all P<0.01), and more calcium nodules were observed in PEMF group than SEMF group (P<0.05). Conclusion: Both 50 Hz 1.8 mT that in SEMF and 50 Hz 0.6 mT PEMF can promote the maturation and mineralization of osteoblasts, and the effect of PEMF is more marked.
Animals ; Calcification, Physiologic ; drug effects ; Cell Differentiation ; Cells, Cultured ; Electromagnetic Fields ; Gene Expression Regulation, Developmental ; radiation effects ; Magnetic Fields ; Osteoblasts ; cytology ; radiation effects ; Rats ; Skull ; drug effects

To study the genic and non-genic regulation of 50 Hz 0.6 mT pulsed electromagnenic fields (PEMF) on rat calvarial osteoblasts (ROB) differentiation.ROBs were achieved by enzyme digestion, and treated with 50 Hz 0.6 mT PEMFs for 1.5 hours after subculture. The alkaline phosphatase (ALP) activity, mRNA transcription of ALP, Runx2 and OSX and protein expression of Runx2 and OSX were detected at 0, 3, 6, 9 and 12 hours after PEMF treatment.The ALP activity at 3 hours after treatment was significantly higher than that in the control(<0.01), while the mRNA transcription of ALP began to increase at 6 hours after treatment. The mRNA transcription of Runx2 increased immediately after treatment and regressed at 6 hours, then increased again. The protein expression of it corresponded but with a little lag. The mRNA transcription of OSX also raised instantly after treatment, then returned to the level of control at 6 hours, and lower than control at 12 hours significantly. The protein expression of it also corresponded but with a bit delay.There are genic regulation for the protein expression of Runx2 and OSX, and non-genic regulation for the ALP activity on the process of 50 Hz 0.6 mT PEMFs prompts ROBs differentiation.
Alkaline Phosphatase ; metabolism ; radiation effects ; Animals ; Cell Differentiation ; genetics ; radiation effects ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit ; metabolism ; radiation effects ; Electromagnetic Fields ; Osteoblasts ; chemistry ; radiation effects ; Osteogenesis ; genetics ; radiation effects ; Rats ; Transcription Factors ; metabolism ; radiation effects

OBJECTIVEAdipose tissue distributes widely in human body. The irradiation response of the adipose cells in vivo remains to be investigated. In this study we investigated irradiation response of adipose-derived stem cells (ASCs) under three-dimensional culture condition.

METHODSASCs were isolated and cultured in low attachment dishes to form three-dimensional (3D) spheres in vitro. The neuronal differentiation potential and stem-liked characteristics was monitored by using immunofluoresence staining and flow cytometry in monolayer and 3D culture. To investigate the irradiation sensitivity of 3D sphere culture, the fraction of colony survival and micronucleus were detected in monolayer and 3D culture. Soft agar assays were performed for measuring malignant transformation for the irradiated monolayer and 3D culture.

RESULTSThe 3D cultured ASCs had higher differentiation potential and an higher stem-like cell percentage. The 3D cultures were more radioresistant after either high linear energy transfer (LET) carbon ion beam or low LET X-ray irradiation compared with the monolayer cell. The ASCs' potential of cellular transformation was lower after irradiation by soft agar assay.

CONCLUSIONThese findings suggest that adipose tissue cell are relatively genomic stable and resistant to genotoxic stress.

Adipose Tissue ; cytology ; radiation effects ; Cell Culture Techniques ; Cell Differentiation ; Flow Cytometry ; Humans ; Neurons ; cytology ; Stem Cells ; cytology ; radiation effects ; X-Rays

This study examined the osteogenic effect of electromagnetic fields (EMF) under the simulated in vivo conditions. Rat bone marrow mesenchymal stem cells (BMSCs) and rat osteoblasts were co-cultured and exposed to 50 Hz, 1.0 mT EMF for different terms. Unexposed single-cultured BMSCs and osteoblasts were set as controls. Cell proliferation features of single-cultured BMSCs and osteoblasts were studied by using a cell counting kit (CCK-8). For the co-culture system, cells in each group were randomly chosen for alkaline phosphatase (ALP) staining on the day 7. When EMF exposure lasted for 14 days, dishes in each group were randomly chosen for total RNA extraction and von Kossa staining. The mRNA expression of osteogenic markers was detected by using real-time PCR. Our study showed that short-term EMF exposure (2 h/day) could obviously promote proliferation of BMSCs and osteoblasts, while long-term EMF (8 h/day) could promote osteogenic differentiation significantly under co-cultured conditions. Under EMF exposure, osteogenesis-related mRNA expression changed obviously in co-cultured and single-cultured cells. It was noteworthy that most osteogenic indices in osteoblasts were increased markedly after co-culture except Bmp2, which was increased gradually when cells were exposed to EMF. Compared to other indices, the expression of Bmp2 in BMSCs was increased sharply in both single-cultured and co-cultured groups when they were exposed to EMF. The mRNA expression of Bmp2 in BMSCs was approximately four times higher in 8-h EMF group than that in the unexposed group. Our results suggest that Bmp2-mediated cellular interaction induced by EMF exposure might play an important role in the osteogenic differentiation of BMSCs.
Alkaline Phosphatase ; biosynthesis ; Animals ; Bone Marrow Cells ; cytology ; radiation effects ; Cell Differentiation ; genetics ; radiation effects ; Cell Proliferation ; radiation effects ; Coculture Techniques ; Electromagnetic Fields ; Mesenchymal Stromal Cells ; radiation effects ; Osteoblasts ; radiation effects ; Osteogenesis ; genetics ; radiation effects ; Rats

Retaining or improving periodontal ligament (PDL) function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation (LPLI) on the proliferation and osteogenic differentiation of human PDL (hPDL) cells. Cultured hPDL cells were irradiated (660 nm) daily with doses of 0, 1, 2 or 4 J⋅cm(-2). Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase (ALP) activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR). Our data showed that LPLI at a dose of 2 J⋅cm(-2) significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J⋅cm(-2) showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate (cAMP) is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.
Adenine ; analogs & derivatives ; pharmacology ; Adenylyl Cyclase Inhibitors ; Alkaline Phosphatase ; analysis ; genetics ; radiation effects ; Anthraquinones ; Bone Morphogenetic Protein 2 ; genetics ; Calcium ; metabolism ; radiation effects ; Cell Culture Techniques ; Cell Differentiation ; radiation effects ; Cell Line ; Cell Proliferation ; radiation effects ; Coloring Agents ; Core Binding Factor Alpha 1 Subunit ; genetics ; Cyclic AMP ; antagonists & inhibitors ; radiation effects ; Gene Expression ; radiation effects ; Humans ; L-Lactate Dehydrogenase ; analysis ; Lasers, Semiconductor ; Low-Level Light Therapy ; instrumentation ; Osteocalcin ; genetics ; Osteogenesis ; genetics ; radiation effects ; Periodontal Ligament ; cytology ; radiation effects ; Radiation Dosage ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Tetrazolium Salts ; Thiazoles

OBJECTIVETo evaluate the adhesion, proliferation and differentiation of osteoblast-like cells on the ultraviolet (UV)-treated titanium in different storing environment, and to find a way to enhance the bioactivity of titanium and to prevent its age-related degradation.

METHODSAcid-etched titanium disks stored under ambient conditions for 4 weeks and treated with UV light for 48 h.Then disks were divided into three groups and placed in a sealed container for 0 h (no-stored,NO group) , 4 weeks (air-stored, AS group) or in a sealed container filled with nitrogen for 4 weeks (nitrogen-stored,NS group) respectively. A group of UV-untreated titanium served as negative control (NC group).The surface morphology was evaluated using scanning electron microscopy (SEM), and hydrophilicity of disks were measured using contact angle measuring device. Cell counting kit-8 was used to measure the cell adhesion and proliferation. Cell differentiation was evaluated by testing alkaline phosphatase (ALP) activity using ALP reagent kit.

RESULTSThere was no difference in surface topography among groups.Contact angels in NS group [(67.70 ± 3.59)°] and NO group [(0.70 ± 0.28)°] were smaller than the others (P < 0.05). Cell adhesion in NS group at 2 h and 4 h point was (0.237 ± 0.006) and (0.578 ± 0.039), respectively, and proliferation at 3 d and 5 d point was (0.743 ± 0.026) and (1.548 ± 0.046) respectively, which were significantly higher than those in AS group [(0.158 ± 0.036), (0.400 ± 0.010), (0.499 ± 0.019) and (1.174 ± 0.062)] and in NC group [(0.161 ± 0.024), (0.390 ± 0.011), (0.508 ± 0.015) and (1.209 ± 0.025)] at the same time point (P < 0.05). How ever the results mention above in the NS group were lower than those in the NO group (P < 0.05). No difference were found between data from the AS group and NS group (P > 0.05). Osteoblast-like cells had an abundant spread on NS and NO group during 2 h incubation, but did not exactly spread on AS and NC group after incubation for 4 h. No difference were found in ALP among groups.

CONCLUSIONSUV treatment can enhance bioactivity of titanium, and nitrogen storage can slow down its biological aging.

Alkaline Phosphatase ; metabolism ; Animals ; Biocompatible Materials ; chemistry ; Cell Adhesion ; radiation effects ; Cell Differentiation ; radiation effects ; Cell Proliferation ; radiation effects ; Cells, Cultured ; Mice ; Microscopy, Electron, Scanning ; Nitrogen ; chemistry ; Osteoblasts ; cytology ; metabolism ; Surface Properties ; Titanium ; chemistry ; radiation effects ; Ultraviolet Rays

OBJECTIVETo investigated the effect of 50-Hz 3.6-mT sinusoidal electromagnetic fields (SEMFs) on the proliferation and differentiation of osteoblasts in vitro.

METHODSThe newborn rat calvarial osteoblasts were isolated by enzyme digestion and randomly divided into 6 groups after one passage. The treatment groups under 50-Hz 3.6-mT SEMFs and controls without SEMFs treatment. The cells were exposed in the SEMFs for 0.5 h, 1.0 h, 1.5 h, 2.0 h, and 2.5 h. They were observed under the contrast phase microscope each day. The calcified nodules were stained by alizarin red. The SEMFs were arranged in spiral appearance after 3 to 5 days.

RESULTSThe SEMFs showed characteristic distribution 3 to 5 days after SEMFs treatment. On the 9(th) day after treatment, the activity of alkaline phosphatase (ALP) significantly increased in the 0.5-h group, whereas the ALP histochemical straining results and the area of calcified nodules were consistent with ALP activity. In the 48-h and 96-h groups, the genetic expression levels of osteoprotegerin and collagen-1 were significantly higher than that in the control group; particularly, the mRNA expression increased in the 0.5-h group.

CONCLUSIONThe SEMFs at 50-Hz 3.6-mT could suppress the proliferation of osteoblasts maturation but stimulate the differentiation and maturation of osteoblasts in vitro.

Animals ; Cell Differentiation ; radiation effects ; Cell Proliferation ; radiation effects ; Cells, Cultured ; Electromagnetic Fields ; Male ; Osteoblasts ; cytology ; radiation effects ; Rats ; Rats, Sprague-Dawley