Effects of 17beta-estradiol on alkaline phosphatase and osteoprotegerin expression in human periodontal ligament cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of 17beta-estradiol on the expression of alkaline phosphatase (ALP) and osteoprotegerin in human periodontal ligament cells.</p><p><b>METHODS</b>Human periodontal ligament cells (hPDLC) were obtained from periodontal tissue explants of teeth extracted for orthodontic treatment ALP activity was determined by PNPP, and OPG protein and corresponding mRNA levels were quantitatively detected by ELISA and RT-PCR RESULTS: ALP activity was significantly increased at 14 days and 21 days (P <0.05). 17beta-E2 of physiological concentration promoted secretion of OPG protein and expression of OPG mRNA (P <0.05). 17beta-E2 with high-dose showed no effect on OPG protein secretion and decrease OPG mRNA expression.</p><p><b>CONCLUSIONS</b>17beta-E2 may have a positive impact on periodontium through promoting expression of ALP and OPG in hPDLC.</p>

Effect of advanced glycation end products on the human gingival fibroblast proliferation and type I collagen synthesis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To apply the synthesized advanced glycation end products (AGE) to the cultured human gingival fibroblast (HGF) in vitro and then to investigate the effects of AGE on the HGF proliferation and type I collagen synthesis and the potential impact of AGE in the repair of periodontium and its molecular mechanism in diabetes-associated periodontitis.</p><p><b>METHODS</b>The HGF was obtained from explants of human healthy gingival tissues by using tissue-explant technique. The AGE was prepared and then added to the culture media, its effect on HGF proliferation at different time duration was examined with MTT colorimetric assay. The type I collagen concentrations in cell culture supernatants and intracellular proteins were detected by ELISA, and the type I collagen mRNA expression of HGF was analyzed by real-time RT-PCR.</p><p><b>RESULTS</b>200 mg/L AGE decreased the A value (P < 0.05) and changed the HGF shape. Incubation of HGF with AGE for 72 hours, the quantities of type I collagen were reduced (P < 0.05), and the expression of type I collagen mRNA was down-regulated (P < 0.05).</p><p><b>CONCLUSIONS</b>The AGE inhibited the HGF proliferation, decreased the synthesis of type I collagen and down-regulated the expression of type I collagen mRNA, impairing the repair of periodontium.</p>