Endemic medicinal plant distribution correlated with stable climate, precipitation, and cultural diversity.

Medicinal plants provide crucial ecosystem services, especially in developing countries such as China, which harbors diverse endemic medicinal plant species with substantial cultural and economic value. Accordingly, understanding the patterns and drivers of medicinal plant distribution is critical. However, few studies have investigated the patterns and drivers of endemic medicinal plants distribution in China. Here, we linked endemic medicinal plants distribution with possible explanatory variables, i.e., paleoclimate change, contemporary climate, altitudinal range and ethnic minority human population size at the prefecture city level in China. Our results show that endemic medicinal plants are concentrated in southern China, especially in southwestern China. Notably, both endemic medicinal plant species richness and the ratio of endemic medicinal plant species richness are negatively associated with glacial-interglacial anomaly in temperature, and positively associated with contemporary precipitation and altitudinal range. In addition, we found that endemic medicinal plant species richness is positively associated with ethnic minority population sizes as well as its ratio to the overall population size. These findings suggest that the distribution of endemic medicinal plants is determined by multiple drivers. Furthermore, our findings stress that dramatic future climate changes and massive anthropogenic activities in southern China pose great challenges to the conservation of China's endemic medicinal plants.

Effect of rat mesenchymal stem cells on hematopoietic reconstitution after allogeneic co-transplantation with bone marrow / 中国实验血液学杂志

To investigate effects of rat bone marrow mesenchymal stem cells (rBMMSC) on hematopoiesis after allo-hematopoietic stem cell transplantation (HSCT), allogeneic BMT model from Fischer 344 rats (RT-1Al) to Wistar rats (RT-1Au) was established; effects of MSCs on hematopoietic reconstitution were studied by survival rate, peripheral blood counts, histological analysis and FACS at day 30 after transplantation. The results showed that (1) MSCs from donor Fisher344 could survive in recipient irradiated by lethal dose and could be found in the thymus, spleen and bone marrow of the recipient at 30 days after cotransplantation with BM by measuring EGFP gene. (2) Cotransplanation of MSCs and BM improved hematopoietic reconstitution. Lymphocyte and platelet counts of peripheral blood in cotransplantation group were higher than those in the control group. Active hematopoiesis and increase of bone marrow nucleated cells were observed in cotransplantation group. MSCs significantly enhanced hematopoiesis of B lymphocyte and megakaryocytopoietic lineages by FACS analysis. It is concluded that (1) MSCs of Fisher344 can be found in the thymus, spleen, bone marrow of the recipients at 30 days after cotransplantion by measuring EGFP gene. (2) hematopoietic reconstitution is significantly enhanced by MSCs cotransplanted with BM.

Osteogenic and neurogenic differentiation of human yolk sacm esenchymal stem cells / 中国病理生理杂志

AIM: To purify human yolk sac mesenchymal ste m cells (hYS-MSC) and investigate its osteogenic and neurogenic differentiation potentials. METHODS: hYS-MSC were separated from yolk sac and purified via p assage culture. The karyotype of hYS-MSCs was analyzed via G-banded characterist ics. Flow cytometric analysis was used to determine the cell cycle and phenotype of hYS-MSC. The AKP expression of hYS-MSC was also tested. Osteogenic different iation of hYS-MSCs was induced by 10 -8mol/L dexamethasone, 10 mmol/L ?-gl ycerophosphate and 50 mg/L vitamin C. Alizarin red S stain was used for identifi cation of mineralization. ?-mecaptoethanol or salviae miltiorrhizae were used t o induce neurogenic differentiation of hYS-MSCs. The expressions of NSE, NF and GFAP were identified by immunohistochemical method. RESULTS: hYS-MSCs could be purified at passages 2 or 3. The cell cycle analysis suggested that hYS-MSCs showed strong proliferational potentials by which the cells kept normal diploid karyotype during the in vitro cultur e. Flow cytometry showed the phenotype of purified hYS-MSCs was uniformly positi ve for CD29, CD44, CD105, and CD166, and negative for reactivity to antigens CD3 4, CD45, or CD86. hYS-MSCs were weakly but clearly positive in AKP. Osteogenic d ifferentiation was appeared after induction of osteogenic differentiation. hYS-M SCs, which were of spindle shape, uniform in size, were induced to pleomorphism osteoblast-like cells which expressed high level of AKP. Aggregates or nodules w ere formed at day 7 and calcium accumulation was detected by alizarin red S stai ning on day 10 or day 14. Neurogenic differentiation of hYS-MSCs was induced by ?-mecaptoethanol or salviae miltiorrhizae. NSE, NF or GFAP positive cells were detected by immunohistochemical staining. CONCLUSIONS: hYS-MSCs have strong proliferation potential and th e normal diploid karyotype is kept during the in vitro culture. The phenoty pe of hYS-MSCs is coincident with adult hMSCs. hYS-MSCs could be induced to dif ferent iate into osteogenic or neurogenic cells.