ABSTRACT
<p><b>OBJECTIVE</b>This study further explores the stromal cell-derived factor-1 (SDF-1)/chemokine receptor 4 (CXCR4) signaling axis mechanism in temporomandibular joint osteoarthritis (OA) by detecting the changes in CXCR4, interleukin (IL)-6, and collagen X expression in the ATDC5 cell line stimulated by the cyclic tensile strain and SDF-1.</p><p><b>METHODS</b>Insulin-transferrin-selenium (ITS) was used to induce ATDC5 cells to differentiate into chondrocyte-like cells. After three weeks, the cells were divided into two groups: those with and without cyclic tensile strain. These groups were further divided into the negative control and SDF-1 groups. Strain force of 20% was applied. After 12 h, the total proteins were extracted from cells of the four groups, and Western blot analysis was used to detect the changes in CXCR4, IL-6, and collagen X expression.</p><p><b>RESULTS</b>SDF-1 could enhance CXCR4, IL-6, and collagen X expressions in the chondrocytes, and 20% tensile strain force could further upregulate the three factors.</p><p><b>CONCLUSION</b>Under abnormal tensile force, SDF-1 can upregulate its specific receptor CXCR4, thus increasing its-binding efficiency and resulting in the activation of the SDF-1/CXCR4 axis. This condition enhances the expressions of IL-6 and other inflammatory factors and directly damages to cartilage tissue. Such damage directly promotes chondrocyte hypertrophy, which enhances collagen X expression.</p>
Subject(s)
Humans , Cell Differentiation , Cell Line , Chemokine CXCL12 , Collagen , Interleukin-6 , Receptors, CXCR4 , Signal Transduction , Stromal CellsABSTRACT
In recent years,nano-silver base inorganic antibacterial agents have been widely used in medicinal and biological fields.The recent research progress on nano-silver base inorganic antibacterial agents used in denture resin base,antibacterial effects,biocompatibility and the influence of the agents on the mechanical properties and color of the resin are introduced.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the stability of resin-dentin bonds against pH cycling.</p><p><b>METHODS</b>Resin-bonded dentin specimens were prepared following manufacturers' instructions, and randomly divided into 3 groups. Among them, 2 groups experienced pH cycling, in which specimens applied CPP-ACP or distilled and deionized water (DDW) on the bonding interface, respectively. Microtensile bond strength (muTBS) testing, failure mode analysis, micromorphological and nanoleakage evaluation of bonding interface and elemental analysis within hybrid layer were performed after 15 days pH cycling. The other group was tested immediately after specimens' preparation without pH cycling.</p><p><b>RESULTS</b>No significant differences were found in muTBS between no pH cycling and pH cycling/CPP-ACP group. Their muTBS were both significantly higher than that of pH cycling/DDW group (P < 0.05). Mixed fractures were the most prevalent failure mode. The quality of hybrid layer in pH cycling/CPP-ACP group was better than that of pH cycling/DDW group, and the nanoleakage was also less severe. Comparing with pH cycling/DDW group, the atomic percentages of Ca in the other two groups were both significantly higher, while those of Ag were statistically lower (P < 0.05).</p><p><b>CONCLUSION</b>Local application of CPP-ACP can promote the stability of resin-dentin bonding interface against pH cycling and prolong bonding degeneration.</p>