Objective To investigate the effect ofstaphylococcal lipoteichoic acid (LTA-sa) on RAW264.7 cells differentiation into osteoclasts. Methods RAW264.7 cells were cultured with LTA-sa of 100 ng/mL (group A), LTA-sa of 200 ng/mL (group B), LTA-sa of 400 ng/mL (group C), receptor activator of nuclear factor κB (NF-κB) ligand (RANKL) of 100 ng/mL as positive control (group D), and equal volume of PBS as blank control (group E) respectively for 5 days. And then, tartrate resistant acid phosphatase staining (TRAP) was used to detect the formation of osteoclast-like cells, Image-Pro Plus 6.0 software to measure the areas of bone resorption pits in Corning Osteo Assay Surface (COAS) wells, and MTT assay to observe the proliferation activity of RAW264.7 cells in group A, B, C, and E. Results After cultured for 5 days, the formation of osteoclast-like cells and bone resorption pits were observed in all groups. The number of osteoclast-like cells and the area of bone resorption pits in groups A, B, C, and D were more than those in group E. And with the increased concentration of LTA-sa, the indexes in groups A, B, and C increased gradually, but were lower than those in group D, and differences were significant between groups (P<0.05). At 5 days after culture, there was no significant difference in absorbance value among the experimental groups (groups A, B, C, and E) (P>0.05). Conclusion LTA-sa has promoting effect on RAW264.7 cells differentiation into osteoclasts.
ObjectiveTo investigate the effects of FTY720-P on EphA2-EphrinA2 bidirectional signaling in osteoclasts.MethodsMurine RAW264.7 macrophages were induced into osteoclasts by dexamethasone and 1α, 25-dihydroxyvitamin D3, and identified by tartrate resistant acid phosphatase (TRAP) staining. Then, the osteoclasts were divided into 2 groups. The osteoclasts were treated with 400 ng/mL FTY720-P in experimental group and without FTY720-P in control group, respectively. After 48 hours of culture, the cells in 2 groups were detected by real-time fluorescent quantitative PCR, Western blot, and immunofluorescence staining. The expressions of EphA2, EphrinA2, RhoA, and the bone reconstruction associated proteins［bone morphogenetic protein 2 (BMP-2) and transform growth factor β1 (TGF-β1)］were analyzed and compared.ResultsRAW264.7 cells were successfully induced into osteoclasts identified by TRAP staining. Compared with control group, the relative expressions of EphA2 and EphrinA2 mRNAs and proteins in experimental group significantly decreased after 48 hours (P<0.05), and the relative expression of RhoA protein also significantly decreased (P<0.05). The relative expressions of BMP-2 and TGF-β1 mRNAs were significantly increased (P<0.05), and those protein expressions were enhanced.ConclusionFTY720-P can down-regulate the expression of RhoA and promote the expressions of TGF- β1 and BMP-2 by affecting the transduction of EphA2-EphrinA2 bidirectional signaling in osteoclasts.
Objective To review the research progress of exosomes (EXOs) derived from different cells in the treatment of osteoporosis (OP). Methods Recent relevant literature about EXOs for OP therapy was extensively reviewed. And the related mechanism and clinical application prospect of EXOs derived from different cells in OP therapy were summarized and analyzed. Results EXOs derived from various cells, including bone marrow mesenchymal stem cells, osteoblasts, osteoclasts, osteocytes, and endothelial cells, et al, can participate in many links in the process of bone remodeling, and their mechanisms involve the regulation of proliferation and differentiation of bone-related cells, the promotion of vascular regeneration and immune regulation, and the suppression of inflammatory reactions. A variety of bioactive substances contained in EXOs are the basis of regulating the process of bone remodeling, and the combination of genetic engineering technology and EXOs-based drug delivery can further improve the therapeutic effect of OP. Conclusion EXOs derived from different cells have great therapeutic effects on OP, and have the advantages of low immunogenicity, high stability, strong targeting ability, and easy storage. EXOs has broad clinical application prospects and is expected to become a new strategy for OP treatment.
ObjectiveTo investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR. MethodsForty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×105 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining. Results The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference (P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application (P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups (P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group (P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application (P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application (P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application (P<0.05). Conclusion Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.