ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of microRNA-20a(MiR-20a) on osteogenic differentiation of mouse C3H/10T1/2 cells and its regulatory mechanism.</p><p><b>METHODS</b>Osteogenic differentiation of C3H/10T1/2 cells were identified by ALP staining and qRT-PCR. MiR-20a mimics and CKIP-1 siRNA were transfected into C3H/10T1/2 cells respectively with lipo3000. The expression of osteoblast marker genes, miR-20a and CKIP-1 were quantitatively assessed by qRT-PCR.</p><p><b>RESULTS</b>miR-20a expression was up-regulated during osteoblast differentiation of C3H/10T1/2 cells. Overexpression of miR-20a promoted osteogenic differentiation. Furthermore, miR-20a inhibited the expression of bone formation negative regulator CKIP-1. Additionally, CKIP-1 knockdown promoted osteogenic differentiation.</p><p><b>CONCLUSION</b>MiR-20a promotes osteogenic differentiation of C3H/10T1/2 cells possibly through inhibiting the expression of CKIP-1.</p>
ABSTRACT
<p><b>BACKGROUND</b>The low-temperature resistance aging performance of Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is the key effective factor that influences the long-term success rate of prosthesis. The objective of this study was to test and compare the aging performances for resisting low temperature of Lava Frame, Cercon Smart, and Upcera Yttria-stabilized zirconia core materials, via analyzing the micro and the crystal phases of the materials, and measure the three-point bending strength and the fracture toughness.</p><p><b>METHODS</b>The three zirconia green bodies were prepared as 60 test samples for three-point bending strength and as 60 test samples for fracture toughness. The test samples for three-point bending strength and fracture toughness were assigned to five groups and were treated respectively for 0, 5, 10, 15, and 20 hours to observe the micro and the crystal phases of the test samples. Then the three-point bending strength and fracture toughness were tested by X-ray diffraction (XRD).</p><p><b>RESULTS</b>The m phase content of Lava Frame was raised from 7.70% to 13.01%; the m phase content of Cercon Smart was raised from 4.95% to 8.53%; and Lava Frame is raised from 10.84% to 35.18%. The three-point bending strengths of the three zirconia core materials were higher than 1100 MPa and the fracture toughness was higher than 3 MPa·m(1/2). The three-point bending strength and the fracture toughness of Upcra zirconia decreased the most, followed by Lava Frame, and then by Cercon Smart.</p><p><b>CONCLUSION</b>The aging resistance sequences of the three zirconia core materials are, from strong to weak, Cercon Smart, Lava Frame, and Upcera.</p>
Subject(s)
Ceramics , Chemistry , Dental Porcelain , Chemistry , Microscopy, Electron, Scanning , Temperature , X-Ray Diffraction , Yttrium , Chemistry , Zirconium , ChemistryABSTRACT
<p><b>OBJECTIVE</b>To explore the capability of human periodontal ligament stem cells (PDLSCs) differentiating into adipose cells in vitro and to determine their changes in cell morphology, structure and function during differentiation.</p><p><b>METHODS</b>PDLSCs isolated by magnetic-activated cell selection were treated continuously with adipogenic medium for 21 d. Then the cell morphology, ultrastructure, adipose specific markers of low density lipoprotein (LPL) and peroxisome proliferator activated receptor-gamma (PPAR-gamma) were analyzed by inverted contrast microscope, trans mission electron microscope (TEM), flow cytometry, immunofluorescence, RT-PCR and Western blot, respectively. These adipose-like cells were also identified by oil red O staining to determine the formation of lipid droplet, and the non-induced cells were used as control.</p><p><b>RESULTS</b>After continuous induction, the treated cells differentiated into adipose-like cells with round shape, and large amount of lipid drop in cytoplasm. 96.54% of the PDLSCs were found to differentiate into adipose cells as showed by flow cytometry, the specific markers of LPL mRNA and PPAR-gamma mRNA, and oil red O staining, respectively. Further, PPAR-gamma protein was detected in the induced cells in a time-dependent manner.</p><p><b>CONCLUSION</b>Human PDLSCs have the potential of differentiating into adipose cells under appropriate condition, and the differentiated cells exhibited characteristics of adipose cells both from cell morphology and from their functions.</p>