Search

BACKGROUND: In recent years, the PI3K/AKT signaling pathway is closely related to bone destruction-related diseases. Inhibitors targeting this signaling pathway are also undergoing extensive research, which provides new ideas for clinical treatment of bone destruction-related diseases. OBJECTIVE: To review the research of PI3K/AKT signaling pathway in bone destruction. METHODS: WanFang and PubMed databases were searched for relevant articles published from January 1998 to August 2019. The retrieval key words were “PI3K/Akt signaling pathway; osteoclasts; osteoblasts; bone destruction” in Chinese and English, respectively. To exclude duplicate studies by reading the title and abstract, finally 67 articles were included in result analysis. RESULTS AND CONCLUSION: An appropriate balance between osteoblast and osteoclast-mediated osteogenesis and bone resorption is necessary to maintain bone homeostasis, and an imbalance between these two biological processes will result in bone destruction. PI3K/Akt signaling pathway is a signal transduction pathway that regulates cell activities and plays an important role in cell proliferation, apoptosis and differentiation. The PI3K/Akt signaling pathway is involved in the inhibition of osteoporosis by promoting osteoblast proliferation, differentiation and bone formation. These results reveal that further exploration on the inhibitors of the PI3K/Akt signaling pathway related to bone destruction will provide new ideas for drug therapy in clinical practice. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have shown that the loss of sex combing protein 1 (Asxl1) can lead to the occurrence of bone dysplasia and bone defects, but the relationship between this factor and bone destruction in the microenvironment of apical periodontitis has not been reported. OBJECTIVE: To study the effect of Asxl1 on proliferation and differentiation of osteoblasts in an inflammatory microenvironment. METHODS: MC3T3-E1 cells were excited by lipopolysaccharide to establish an in vitro inflammatory microenvironment. The best concentration and optimal action time of lipopolysaccharide were screened by cell counting kit-8 test. MC3T3-E1 cells were then stimulated with 20 mg/L lipopolysaccharide for 24 hours. The expression levels of Asxl1 protein and mRNA were detected by immunofluorescence and real-time PCR, respectively. After lipopolysaccharide stimulated the formation of inflammatory microenvironment, Asxl1-Si RNA was transfected for 24 hours, cell counting kit-8 was applied to detect the activity of cell proliferation, and real-time PCR was used to detect the expression levels of Asxl1 and osteogenic related genes ALP and RUNX2 mRNA. RESULTS AND CONCLUSION: After lipopolysaccharides stimulation of MC3T3-E1 cells, the expression levels of Asxl1 protein and mRNA were decreased. Under the inflammatory microenvironment, the proliferation activity of MC3T3-E1 cells transfected with Asxl1-Si RNA for 24 hours was significantly decreased, and the expression levels of Asxl1, ALP and RUNX2 mRNA were markedly decreased. These findings indicate that Asxl1 may influence the proliferation and differentiation of osteoblasts by involvement in the process of inflammatory reaction, thereby participating in bone destruction. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exosomes have been shown to promote bone regeneration, but whether extracting exosomes from fetal bovine serum can promote osteogenesis remains controversial. OBJECTIVE: To observe the effect of fetal bovine serum exosomes on the proliferation of osteoblasts, so as to provide new ideas for treating bone destruction. METHODS: Exosomes were extracted from fetal bovine serum by ultracentrifugation method. Electron transmission microscopy and western blot assay were used to verify whether the exosomes were successfully extracted. MC3T3-E1 cells were interfered with 10 mg/L fetal bovine serum. The effect of exosomes on the proliferation of osteoblasts was detected by cell counting kit-8 assay. The effects of exosomes on the expression of osteogenic markers bone morphogenetic protein-2 and osteopontin protein were detected by western blot assay. MC3T3-E1 cells cultured in the fetal bovine serum without exosomes were as control group. RESUITS AND CONCLUSION: The typical lipid bilayer membrane structure of exosomes was observed, and the size was between 30-150 nm. The exosome surface marker factor CD81 was positive, while the microcapsule surface marker CD40 was negative. The results of cell counting kit-8 assay showed that the proliferative capacity in the exosomes group was significantly higher than that in the control group (P < 0.05). The expression levels of bone markers bone morphogenetic protein-2 and osteopontin in the exosome group were significantly higher than those in the control group (P < 0.05). The exosomes extracted from fetal bovine serum can promote the proliferation of osteoblasts, providing a new idea for the clinical treatment of bone destruction. [ABSTRACT FROM AUTHOR]