Reciprocal interactions between hemopoietic stromal cells and immature hemopoietic cells in human spleens obtained from 20 fetuses of 10-28 weeks gestation were observed by transmission electron microscopy and scanni...Reciprocal interactions between hemopoietic stromal cells and immature hemopoietic cells in human spleens obtained from 20 fetuses of 10-28 weeks gestation were observed by transmission electron microscopy and scanning electron microscopy. The close association of stromal cells with immature hemopoietic cells was confirmed under the electron microscope and a presumptive HIM (Hemopoietic inductive microenvironment) was visualized. In regions of immature hemopoietic cell-reticular cell, endothelial cell, macrophage and interdigitating cell contact,some communicating structures were found between the plasma membranes of adjacent cells; moreover, the cytoplasm of these four stromal cells were full of various kinds of organelles. These results suggest that reticular cells,endothelial cells, macrophages and interdigitating cells are component parts of the HIM of human fetal spleen and that these cells have a nurturing function in relation to hemopoietic cells.展开更多
Fetal liver （FL） is an intricate and highly vascularized hematopoietic organ, which can support the extensive expansion of hematopoietic stem cells （HSCs） without loss of stenmess, as well as of the downstream lin...Fetal liver （FL） is an intricate and highly vascularized hematopoietic organ, which can support the extensive expansion of hematopoietic stem cells （HSCs） without loss of stenmess, as well as of the downstream lineages of HSCs. This powerful function of FL largely benefits from the niche （or microenvironment）, which provides a residence for HSC expansion. Numerous studies have demonstrated that the FL niche consists of heterogeneous cell populations that associate with HSCs spatially and regulate HSCs functionally. At the molecular level, a complex of cell extrinsic and intrinsic signaling network within the FL niche cells maintains HSC expansion. Here, we summarize recent studies on the analysis of the FL HSCs and their niche, and specifically on the molecular regulatory network for HSC expansion. Based on these studies, we hypothesize a strategy to obtain a large number of functional HSCs via 3D reconstruction of FL organoid ex vivo for clinical treatment in the future.展开更多
文摘Reciprocal interactions between hemopoietic stromal cells and immature hemopoietic cells in human spleens obtained from 20 fetuses of 10-28 weeks gestation were observed by transmission electron microscopy and scanning electron microscopy. The close association of stromal cells with immature hemopoietic cells was confirmed under the electron microscope and a presumptive HIM (Hemopoietic inductive microenvironment) was visualized. In regions of immature hemopoietic cell-reticular cell, endothelial cell, macrophage and interdigitating cell contact,some communicating structures were found between the plasma membranes of adjacent cells; moreover, the cytoplasm of these four stromal cells were full of various kinds of organelles. These results suggest that reticular cells,endothelial cells, macrophages and interdigitating cells are component parts of the HIM of human fetal spleen and that these cells have a nurturing function in relation to hemopoietic cells.
基金supported by the National Natural Science Foundation of China (81530004, 31425016)the Ministry of Science and Technology of China (2016YFA0100500)the Strategic Priority Research Program of the Chinese Academy of Sciences, China (XDA16010104)
文摘Fetal liver （FL） is an intricate and highly vascularized hematopoietic organ, which can support the extensive expansion of hematopoietic stem cells （HSCs） without loss of stenmess, as well as of the downstream lineages of HSCs. This powerful function of FL largely benefits from the niche （or microenvironment）, which provides a residence for HSC expansion. Numerous studies have demonstrated that the FL niche consists of heterogeneous cell populations that associate with HSCs spatially and regulate HSCs functionally. At the molecular level, a complex of cell extrinsic and intrinsic signaling network within the FL niche cells maintains HSC expansion. Here, we summarize recent studies on the analysis of the FL HSCs and their niche, and specifically on the molecular regulatory network for HSC expansion. Based on these studies, we hypothesize a strategy to obtain a large number of functional HSCs via 3D reconstruction of FL organoid ex vivo for clinical treatment in the future.
