RESUMO
@#【Objective】To investigate the role and the potential target of miR-199a-3p in mouse cardiac hypertrophy.【Methods】Neonatal mouse ventricular cardiomyocytes（NMVC）were isolated from the hearts of 0- 3- day- old newborn C57BL/6 mice. MiR-199a-3p mimic and retinoblastoma transcriptional corepressor 1（Rb-1）siRNA were transfected in? to NMVC to elevate the level of miR-199a-3p and inhibit Rb-1 expression，respectively. NMVC were stained with FITC- phalloidin solution to determine the size of NMVC. Dual luciferase reporter assay was performed to identify the interaction between miR- 199a- 3p and the 3’UTR of Rb- 1. mRNA and protein expression of cardiac hypertrophy associated genes were determined by RT-qPCR and Western blotting assay，respectively.【Results】（1）Over-expression of miR-199a-3pcould significantly enhance the expression of cardiac hypertrophy-related genes in NMVC ；（2）Dual-luciferase reporter assay results verified that miR- 199a-3p can interact with the 3’UTR of Rb-1. MiR-199a-3p could suppress Rb-1 ex? pression at the post-transcriptional level；（3）Functionally，miR-199a-3p mimic，consistent with Rb-1 siRNA，could increase cell size and the expression of Nppa，Acta1 and Myh7 in NMVC，and promote the nuclear translocation of E2f2 in NMVC.【Conclusions】MiR-199a-3p promotes the entry of E2f2 into the nucleus through inhibiting the expression of Rb-1，contributing to cardiomyocyte hypertrophy.
RESUMO
PURPOSE: To evaluate the shear bond strength and bonding ability between the new nano-hydroxyapatite composite resin and tooth structure. METHODS: Thirty-six healthy isolated molars were randomly assigned to 3 groups according to the material employed: new nano-hydroxyapatite composite resin, composite resin karisma and glass ionomer cement. After thermal cycling, the data of shear bond strength was recorded, and the type of specimen fracture section was observed under stereo microscope. The data was analyzed statistically by SPSS17.0 software package. RESULTS: The average shear bonding strength of nano-hydroxyapatite composite resin was (11.23±4.6082) N/mm(2), and that of composite resin charisma and glass ionomer cement was (14.49±7.9855) N/mm(2) and(10.08±6.3701) N/mm(2), respectively. No significant difference was found among 3 groups. The bonding fracture mode of each specimen had no significant difference(P>0.05). CONCLUSIONS: As a new dental restorative material, new nano-hydroxyapatite composite resin has superior bonding ability and can be used in clinical therapy. Supported by Natural Science Foundation of Shandong Province (Y2008C159).
