RESUMO
Panax notoginseng (PN) has been used as a qi- and blood-activating (Huoxue) drug for thousands of years in China. It has also been widely used as an anticancer drug at present. As a Huoxue drug, the effect of PN on hematopoietic differentiation in tumor-bearing body has been paid more and more attention. Our research found that panax notoginseng saponins (PNS), especially panaxadiol saponins (PDS) and its aglucon 20(S)-Protopanaxdiol (PPD), could improve the immunosuppressive state by regulating the abnormal hematopoietic differentiation in a tumor-bearing body by multiple ways. An interesting phenomenon is that PDS reduced the neutrophil-lymphocyte ratio (NLR) via its inhibition effect on the granule-monocyte differentiation of spleen cells, which is associated with a decrease in the secretion of tumor MPO, G-CSF, PU.1, and C/EBPα. Otherwise, PDS increased the proportion of both hematopoietic stem cells and erythroid progenitor cells in the bone marrow, but inhibited spleen erythroid differentiation via inhibiting secretion of tumor EPO, GATA-1, and GATA-2. This study suggests that PNS regulated the tumor-induced abnormal granule-monocyte differentiation of hematopoietic stem cells, affecting the distribution and function of haemocytes in tumor-bearing mice.
RESUMO
As the key cells in a three-dimensional scaffold within the thymus, Thymic epithelial cells (TECs) play critical roles in the homing, migration and differentiation of T cell precursors through adhesive interactions and the release of various cytokines. In this study, primary cultures of mouse TECs were isolated and identified with TEC-specific antibodies CK5 and CK8. These TECs were immortalized by retroviral transduction of simian virus (SV) 40 large T antigen. We then compared the functions of TECs and immortalized TECs (iTECs). Cell morphology and the proliferative capacity of TECs and iTECs were observed by inverted microscope photography and crystal violet assay after passage. A soft agar assay was then performed to observe their clone formation ability. The expression levels of epithelial cell related factors, such as IL-7, Lptin, Pax-9, Sema3A and et al., were detected by IF and qPCR. TECs were co-cultured with human acute monocytic leukemia cells (THP-1), and the effect of TECs on promoting THP-1 proliferation was observed with flow cytometry and CFSE labeling. Senescence-associated ß-galactosidase assay was measured to detect the anti-aging capabilities of the cells. Cell cycle distribution was analyzed by propidium iodide (PI) staining, and paclitaxel (PTX)-induced apoptosis was detected by Annexin V-PI staining to evaluate the anti-apoptotic ability of the cells. Throughout, we found that the immortalized TECs still retain the characteristics of primary TECs, such as the morphology, function and epithelial characteristics; however, iTECs have stronger capabilities in proliferation and anti-aging. Our research suggests that the iTECs were successfully immortalized by SV40 large T antigen, and that the biological characteristics and functions of iTECs were similar to the original TECs. This immortalized cell can be used as an efficient cell model in functional research of the thymus substituting primary TECs with iTECs.