Overview of the main biological mechanisms linked to changes in periodontal ligament stem cells and the inflammatory microenvironment / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Periodontitis is a complex chronic inflammatory disease. The invasion of pathogens induces the inflammatory microenvironment in periodontitis. Cell behavior changes in response to changes in the microenvironment, which in turn alters the local inflammatory microenvironment of the periodontium through factors secreted by cells. It has been confirmed that periodontal ligament stem cells (PDLSCs) are vital in the development of periodontal disease. Moreover, PDLSCs are the most effective cell type to be used for periodontium regeneration. This review focuses on changes in PDLSCs, their basic biological behavior, osteogenic differentiation, and drug effects caused by the inflammatory microenvironment, to provide a better understanding of the influence of these factors on periodontal tissue homeostasis. In addition, we discuss the underlying mechanism in detail behind the reciprocal responses of PDLSCs that affect the microenvironment.

Inhibitory Effects of Periplocin from Cortex Periplocae on Human Lung Cancer Cell Line QG56 / 天津医药

Objective To investigate the inhibitory effects of periplocin from cortex periplocae (CPP) on human lung cancer cell line QG56 and to discuss its mechanism. Methods QG56 cells were cultured in vitro. The final concentrations of CPP in control group were 1.25, 2.50, 5.00, 10.00 and 20.00μg/L. QG56 cells were treated with ascending concentration of CPP for 24 h, 48 h and 72 h. The cell proliferation was measured using MTT method. The morphological changes of QG56 cells were observed under inverted microscope. Flow cytometry (FCM) was used to detect the effects of CPP on cell cycle and cell apoptosis. The expression of apoptosis associated gene bax mRNA in QG56 cells was detected by RT-PCR. The expres-sion of bax protein before and after treatment of CPP was examined by SP immunocytochemistry. Results The inhibitory ef-fect of CPP on the proliferation of QG56 cells was increased with the increasing concentrations of CPP and the prolonged du-ration of treatment. The morphological changes were displayed in QG56 exposed to CPP. The results of FCM showed that CPP caused cell cycle arrest at G0/G1 phase. The apoptotic rate of QG56 cells was significantly increased after CPP treatment for 48 h (P<0.05). The expression of bax mRNA was increased in QG56 exposed to CPP. The result of immunocytochemis-try indicated that CPP up-regulated the expression of bax protein. Conclusion CPP showed significant inhibitory effect on human lung cancer cell lines QG56 through inducing cell cycle arrest and apoptosis.