K (lysine) acetyltransferase 2A affects the osteogenic differentiation of periodontal ligament stem cells through the canonical Wnt pathway / 华西口腔医学杂志

OBJECTIVE@#This study aims to investigate the mechanism of K (lysine) acetyltransferase 2A (KAT2A) regulation and control on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs).@*METHODS@#The expression levels of KAT2A in PDLSCs were compared from each generation of the normal (H-PDLSCs) and periodontitis tissues (P-PDLSCs). The influences of KAT2A gene interference on the osteogenic differentiation of PDLSCs were also detected. In addition, the influences of the KAT2A gene interference to the canonical Wnt pathway and ligands were detected. The upstream and down-stream relationships between KAT2A and canonical Wnt pathway were also determined.@*RESULTS@#The decreased expression of KAT2A in PDLSCs from the inflammatory tissue in each generation was compared with that in PDLSCs from the healthy tissue, and the difference was statistically significant (P<0.05). When the KAT2A gene was disrupted, the osteogenesis ability of PDLSC was declined, and the difference was statistically significant (P<0.05). The canonical Wnt pathway was activated, and the antagonist Dickkopf-1 (DKK-1) was reduced. After the DKK-1 addition, the osteogenic differentiation of the disturbed PDLSCs was recovered, and KAT2A was unaffected.@*CONCLUSIONS@#The KAT2A expression in PDLSCs was decreased because of perio-dontitis. The classical Wnt pathway was activated to inhibit the osteogenic differentiation of the cells.

Endophytic fungus Purpureocillium sp. A5 protect mangrove plant Kandelia candel under copper stress

Abstract Mangrove is an important ecosystem in the world. Mangrove ecosystems have a large capacity in retaining heavy metals, and now they are usually considered as sinks for heavy metals. However, the mechanism of why the soil of mangrove ecosystems can retain heavy metal is not certain. In this research, endophytic fungus Purpureocillium sp. A5 was isolated and identified from the roots of Kandelia candel. When this fungus was added, it protected the growth of K. candel under Cu stress. This can be illustrated by analyzing chlorophyll A and B, RWC and WSD to leaves of K. candel. Purpureocillium sp. A5 reduces uptake of Cu in K. candel and changes the pH characterization of soil. Furthermore, A5 increase the concentration of Cu complexes in soil, and it enhanced the concentration of carbonate-bound Cu, Mn-Fe complexes Cu and organic-bound Cu in soil. Nevertheless, a significant reduction of the Cu ion was noted among A5-treated plants. This study is significant and illustrates a promising potential use for environmental remediation of endophytes, and also may partially explain the large capacity of mangrove ecosystems in retaining heavy metals.

Comparison of osteogenic differentiation abilities of mesenchymal stem cells from different sources of hBMSCs / 口腔疾病防治

Objective@#To compare the osteogenic differentiation abilities of human bone marrow mesenchymal stem cells (hBMSCs) from different sources, and to provide basis for choosing a new source of seed cells in bone tissue engineering.@*Methods@# Jaw bone-marrow-derived mesenchymal stem cells (JMMSCs) were isolated from orthognathic surgical sites and cultured by limited dilution for single cell clone. Long bone-marrow-derived mesenchymal stem cells (BMMSCs) were obtained from bone marrow of volunteers and isolated by density gradient centrifugation method. Flow cytometry was used to detect the surface markers of both cells. Osteogenic ability was assessed by PCR and Western Blot after osteogenic differentiation for the following molecules: Runx2, COL-1 and OCN. Alizarin red staining was used for determining the ability of cell mineralization after osteogenic differentiation. @*Results @#The expressions of cell surface markers CD90 and CD105 were positive in both type of cells, while CD34, CD14 and CD45 were all negative. After 21 days of osteogenic induction, JMMSCs formed significantly more mineralized nodules than BMMSCs. After 7, 14, 21 days of osteogenic induction, JMMSCs expressed more osteogenic-related molecules than BMMSCs.@*Conclusion@#The osteogenic differentiation capacity and mineralization ability of JMMSCs are significantly higher than BMMSCs. Jaw bone might be a more suitable source of seed cells in bone tissue engineering compared with long bone.