Thymosin Beta 15 Alters the Spatial Development of Thymic Epithelial Cells.

The thymus is the most sensitive organ under various pathophysiological conditions, such as aging, starvation, and infection. As a key stromal cell for T cell development, it is well-known that thymic epithelial cells (TECs) play an important role in the thymus response to the external environment. Thymosin beta 15 (Tß15) is a G-actin binding protein secreted by TECs, it plays an important role in maintaining the dynamic balance of actin, angiogenesis, axonal formation, and wound healing, but the relationship between Tß15 and TECs is not clear yet. Here, we show the impact of Tß15 on the TEC's spatial development, as well as the T-cell differentiation and thymic output. As a result, TEC is the main effector cell of Tß15 in the thymus. Tß15 OX inhibits the chemotaxis of TECs to the medulla and subsequently blocks the positive selection of thymocytes from CD3+TCRß+CD4+CD8+ double positive cells to CD3+TCRß+CD4+CD8- single-positive (CD4SP) cells. Tß15-knockdown accelerates the reticular differentiation of astral TECs and medullary TECs. Importantly, mice implanted with Tß15-knockdown iTECs show high thymic output but low peripheral T cell maturity and activity. In a word, our results explain the role of Tß15 on the differentiation and function of TECs and provide a new perspective for understanding the process of thymus development and degeneration.

Cell metabolomics study on the anticancer effects of Ophiopogon japonicus against lung cancer cells using UHPLC/Q-TOF-MS analysis.

Ophiopogon japonicus (OJ) is a traditional Chinese herbal medicine that has been used for thousands of years. Recently, the anticancer effects of OJ have been reported in multiple types of cancer, particularly in lung cancer. However, the underlying mechanisms remain unclear. In present study, the effects of OJ against NCI-H1299 human lung cancer cells were investigated, and the underlying mechanisms were explored using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS)-based cell metabolomics. As a result, OJ inhibited the proliferation, induced the apoptosis and suppressed the migration of NCI-H1299 cells. A total of 22 differential metabolites responsible for the effects of OJ were screened and annotated based on the LC-MS-based cell metabolomics approach. The altered metabolites were involved in three metabolic pathways, including glycerophospholipid metabolism, ether lipid metabolism and glutathione metabolism. These results showed that cell metabolomics-based strategies are promising tools to discover the action mechanisms of OJ against lung cancer cells.

Identification and functional study of immortalized mouse thymic epithelial cells.

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.

Epimedin C Protects H2O2-Induced Peroxidation Injury by Enhancing the Function of Endothelial Progenitor HUVEC Populations.

Endothelial cell injury and apoptosis induced by oxidative stress serve important roles in many vascular diseases. The repair of endothelial cell vascular injury relies on the function of local endothelial progenitor cells (EPCs). Our previous study indicated that epimedin C, a major flavonoid derived from Herba epimedii (yin yang huo), could promote vascularization by inducing endothelial-like differentiation of mesenchymal stem cells C3H/10T1/2 both in vivo and in vitro. In view of the significant cardiovascular protective effects of Herba epimedii, we detected a protective effect of epimedin C on hydrogen peroxide (H2O2)-induced peroxidation injury in human umbilical vein endothelial cells (HUVECs) and the role of EPC in this process. The results show that epimedin C increased the expression of the stem cell marker, CD34 and PROM1, and subsequently enhanced the expression and function of vascular endothelial growth factor and matrix metalloproteinase (MMP)-2 in local vascular endothelial cells. In conclusion, epimedin C protects H2O2-induced peroxidation injury by enhancing the function of endothelial progenitor HUVEC populations.