Stem cell can both self-renew and have the ability to differentiate into one or more cell types that perform normal tissue/organ function throughout life, including embryonic stem cell and adult stem cell. The treatment with stem cells will be widely used in the future. This article reviews recent advances in studies of the use of embryonic stem cells and spermatogonial stem cells in male reproduction.
Embryonic Stem Cells ; transplantation ; Humans ; Male ; Spermatogonia ; cytology ; Stem Cell Transplantation ; trends ; Stem Cells ; cytology

Red blood cell transfusion is an effective method to treat acute hemorrhage and severe anemia. However, blood source from donors is very limited, and transfusion-transmitted diseases occurred frequently, thus threatening human health. Therefore, the safe, abundant and functional blood source is needed. Generation of blood cells from human pluripotent stem cells(hPSC) will offer alternative approach. Lots of studies have been focused on erythroid cell differentiation in vitro, including how to enhance efficiency and improve their function. In this review, the research advances on differentiation methods and the regulatory mechanism are summarized. In addition, the progress in PSC differentiation into erythrocytes and the problems to be solved are discussed briefly.
Cell Differentiation ; Embryonic Stem Cells ; cytology ; Erythrocytes ; cytology ; Humans ; Induced Pluripotent Stem Cells ; cytology

Human pluripotent stem cells (PSCs) such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) hold great promise in regenerative medicine as they are an important source of functional cells for potential cell replacement. These human PSCs, similar to their counterparts of mouse, have the full potential to give rise to any type of cells in the body. However, for the promise to be fulfilled, it is necessary to convert these PSCs into functional specialized cells. Using the developmental principles of neural lineage specification, human ESCs and iPSCs have been effectively differentiated to regional and functional specific neurons and glia, such as striatal gama-aminobutyric acid (GABA)-ergic neurons, spinal motor neurons and myelin sheath forming oligodendrocytes. The human PSCs, in general differentiate after the similar developmental program as that of the mouse: they use the same set of cell signaling to tune the cell fate and they share a conserved transcriptional program that directs the cell fate transition. However, the human PSCs, unlike their counterparts of mouse, tend to respond divergently to the same set of extracellular signals at certain stages of differentiation, which will be a critical consideration to translate the animal model based studies to clinical application.
Astrocytes ; cytology ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; Humans ; Neuroglia ; cytology ; Neurons ; cytology ; Pluripotent Stem Cells ; cytology

BACKGROUNDHuman embryonic stem cells can propagate indefinitely in vitro and are able to differentiate into derivatives of all three embryonic germ layers. The excitement surrounding human embryonic stem cells lies largely in their potential to produce specialized cells that can be used for transplant therapies. However, further investigation requires additional cell lines with varying genetic background. Therefore, efforts to derive and establish more human embryonic stem cell lines are highly warranted.

METHODSSurplus embryos (blastocysts) from donors were used to isolate the inner cell mass by immunosurgery. All cells were cultured continuously on irradiated murine embryonic fibroblasts feed layer and likely human embryonic stem cell colonies were subsequently characterized by cell surface marker staining, karyotyping and teratoma formation.

RESULTSTwo human embryonic stem cell lines (SYSU-1 and SYSU-2) were established from surplus embryos. The two lines express several pluripotency markers including alkaline phosphatase, SSEA-4, Tra-1-60, Oct-4, Nanog and Rex-1. They remain in undifferentiated state with normal karyotype after prolonged passages and can form embryoid bodies in vitro and teratoma in vivo.

CONCLUSIONTwo new human embryonic stem cell lines have been established from surplus embryos. They can be used to understand selfrenewal and differentiating mechanisms and provide more choices for regenerative medicine.

Seed cells are prerequisite for reconstruction of artificial tissues/organs by tissue engineering approach. It has been widely accepted that stem cells are the best candidate for tissue engineering. The successful repair of tissue damages with adult stem cell mediated tissue engineering therapy in both animal models and patients has demonstrated the feasibility of using this technique for tissue/organ regeneration. Further studies in allogeneic adult stem cells and the establishment of universal embryonic stem cells will be critical for the industrialization of tissue engineering in future.
Adult Stem Cells ; cytology ; Animals ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; Humans ; Tissue Engineering

Male germ stem cells (mGSCs), which is in testis after sex differentiation, derive from primordial germ cells. In this study, bovine mGSCs were isolated from testis of 20 weeks fetuses. Number of CD9 positive cells of the cells through two-steps adhering plates velocity different was 95.8% by flow cytometer. The carina-type cells clones and the plane-type cells clones appeared in co-cultured system. One cells lines had been successively maintained for 4 passages, and the cells clusters showed AKP positive staining. The cells clusters showed nest-shape in third passage showed SSEA1 and Oct-4 positive staining. These cells can also spontaneously differentiate into c-kit positive staining germ cells, and the cells were directional induced to formaactin positive staining cardiac-like cells cluster and NF positive staining neuron-like cells. The conclusion showed that male germ stem cells from 20 weeks bovine fetuses could be in vitro formed like embryonic stem cells.
Animals ; Cattle ; Cell Differentiation ; physiology ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; Fetus ; cytology ; Male ; Pluripotent Stem Cells ; cytology ; Spermatozoa ; cytology

Investigation on the pathways of embryonic stem cells differentiation into insulin-producing cells is of importance to pancreatic tissue-engineering. Instead of passing through the classic multi-step-inducing method, the expanded embryonic stem cells that were cultured and expanded in the presence of mouse embryonic fibroblast feed-layer and leukemia inhibitory factor (LIF) were induced into insulin-producing cells directly. The results showed a similar consequence from two different inducing cultures. Without passing through a so-called indispensable differentiation phase, the neural-precursor-cell-stage, the expanded embryonic stem cells could be induced into insulin-producing cells. The insulin-producing cells population resulting from our modified method were similar to that resulting from the classic multi-step method (passing through the neural-precursor-cells-stage), thus suggesting that neural-precursor-cell-phase is not the indispensable checkpoint of embryonic stem cell differentiation into insulin-producing cells. Embryonic stem cells can be induced into insulin-producing cell by classic multi-step inducing method or by direct inducing method.
Animals ; Cell Differentiation ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; Insulin-Secreting Cells ; cytology ; Mice ; Neural Stem Cells ; cytology

Embryonic stem cells are derived from inner cell mass of the preimplanted blastocyst or from primordial germ cells of the early embryos, with the capacity of unlimited growth and differentiation potential. Embryonic stem cells(ES cells) can differentiate into all kinds of cells and organs under proper condition. Due to this characteristics ES cells have the attractive prospect in basic research, transplantation and gene therapy.
Blastocyst ; cytology ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; Germ Cells ; cytology ; Humans ; Research ; trends

The neural stem cells in Wistar rats were cultured in vitro, purified, and transplanted into C6 glioma model in order to observe their biological characters and provide a basic foundation for treatment of neurological diseases by neural stem cell transplantation. The cells at hippocampal area from gestation 15-day rats were cultured in vitro, and frozen and preserved in liquid nitrogen. C6 tumor-bearing models (n=25) and neural stem cells transplantation models (n=35) were established. When the tumor grew to 3 to 4 weeks, 5 rats in each group were randomly selected for MRI examination. At different intervals, the rats were perfused and sampled for HE staining, GFAP and BrdU immunohistochemical staining. The results showed that after resuscitation of neural stem cells at 1-4 passages, the cell viability was 40%-63% with the difference being not significant. The cells could proliferate, passage, and most cells transplanted into glioma model survived. The mean survival time in neural stem cell transplantation group and control was 4.28 and 3.88 weeks respectively, and the average tumor size in the former was smaller than in the latter. It was concluded that embryonic neural stem cells in rats could proliferate and differentiate, and after resuscitation the biological characteristic and viability of the cells were not influenced. Neural stem cells had inhibitory effects on the growth of glioma cells and could prolong the survival of rat model.
Brain/cytology ; Brain Neoplasms/*therapy ; Cells, Cultured ; Embryonic Stem Cells/cytology ; Embryonic Stem Cells/*transplantation ; Glioma/*therapy ; Neoplasm Transplantation ; Neurons/*cytology ; Random Allocation ; Rats, Wistar ; Stem Cell Transplantation

Stem cell research is a innovative technology that focuses on using undifferentiated cells able to self-renew through the asymmetrical or symmetrical divisions. Three types of stem cells have been studied in laboratory including embryonic stem cell, adult stem cells and induced pluripotent stem cells. Embryonic stem cells are pluripotent stem cells derived from the inner cell mass and it can give rise to any fetal or adult cell type. Adult stem cells are multipotent, have the ability to differentiate into a limited number of specialized cell types, and have been obtained from the bone marrow, umbilical cord blood, placenta and adipose tissue. Stem cell therapy is the most promising therapy for several degenerative and devastating diseases including digestive tract disease such as liver failure, inflammatory bowel disease, Celiac sprue, and pancreatitis. Further understanding of biological properties of stem cells will lead to safe and successful stem cell therapies.
Adult Stem Cells/cytology/metabolism/transplantation ; Embryonic Stem Cells/cytology/metabolism/transplantation ; Humans ; Induced Pluripotent Stem Cells/cytology/metabolism/transplantation ; Stem Cells/*cytology/metabolism