Exploring the Mechanism of CircRNA-vgll3 in Osteogenically Differentiated Human Bone Marrow Mesenchymal Stem Cells

Objective:To explore the mechanism of circRNA-vgll3 in osteogenic differentiation of human bone marrow mesenchymal stem cells.Methods:BMSCs cells were transfected with circRNA-vgll3,and divided into circRNA-vgll3 high-level group,circRNA-vgll3 low-level group,and negative control group(circRNA-vgll3 not transfected)according to the amount of transfection.The proliferation and apoptosis of BMSCs osteoblasts in each group were analyzed,and the alkaline phosphatase(ALP)activity,type I collagen gray value,bone morphogenetic protein 2(BMP-2),Runx2 protein,and mRNA expression levels were detected.Results:The circRNA-vgll3 low-level group had a significant inhibitory effect on the proliferation of BMSCs osteoblasts,and the apoptosis rate of the circRNA-vgll3 low-level group was significantly higher than that of the circRNA-vgll3 high-level group(P<0.05);ALP activity,type I collagen gray value,BMP-2,Runx2 protein,and mRNA expression levels in the high-level circRNA-vgll3 group were significantly higher than those in the low-level circRNA-vgll3 group,and the difference was statistically significant(P<0.05).Conclusion:Overexpression of circRNA-vgll3 can promote the osteogenic differentiation ability of BMSCs,while low expression of circRNA-vgll3 can inhibit the osteogenic differentiation ability of BMSCs.The main mechanism of action is that circRNA-vgll3 can affect osteogenic differentiation by regulating the Runx2 protein.

Geochronology,Geochemistry and Geological Significance of Volcanic Rocks of the Bangba District,Western Segment of the Central Lhasa Subterrane

The Lhasa terrane records voluminous magmatism related to the subduction of the Neo-Tethyan oceanic lithosphere,the study of which constrains the tectonomagmatic evolution of the region.We report zircon U-Pb ages,whole-rock compositions and Sr-Nd isotopic data from volcanic rocks in the Bangba district within the central Lhasa subterrane to constrain their magmatic source and petrogenesis.Zircon U-Pb dating of two volcanic rock samples yields End Cretaceous ages of 70.0±0.8 and 74.3±1.2 Ma.The rocks have high SiO_(2)(65.41 wt.%-68.45 wt.%),Al_(2)O_(3)(16.16 wt.%-16.59 wt.%)and K_(2)O(5.00 wt.%-6.73 wt.%)contents,and low TFe2O3(2.33 wt.%-2.79 wt.%),MgO(0.64 wt.%-1.44 wt.%)and TiO_(2)(0.61 wt.%-0.65 wt.%)contents,with aluminium saturation indices(A/CNK)of 0.99-1.06.The major-and trace-element compositions of the rocks show they are metaluminous to slightly peraluminous high-K calc-alkaline trachydacite.The relatively high SiO2 and Sr-Nd isotopic compositions((^(87)Sr/^(86)Sr)_(i)=0.722654,0.722038 and 0.725787 andε_(Nd)(t)=-12.27,-12.36 and-6.09,respectively)indicate that the trachydacites formed by partial melting of crustal material.The trachydacites are relatively enriched in light rare earth elements,depleted in heavy rare earth elements,have high(La/Yb)_(N) and(Gd/Yb)_(N) ratios(>61 and>6,respectively),and low Y(<18 ppm)and Yb(<18 ppm)contents,indicating they most likely formed from partial melting of lower crust in the garnet stability field.Considering the geodynamic setting of the region during this period,partial melting of the ancient Lhasa crust was likely triggered by underplating mafic magmas during rollback of the Neo-Tethyan slab.