Adult stem cells are the multi-potential cells, which exist in fetal and adult tissues. It can reproduce itself (undergo self-renewal) or give rise to more specialized (differentiated) cells. Under certain inducing conditions, adult stem cells can acquire the ability to differentiate into different tissue cells. Multipotent adult progenitor cells (MAPC), an alternative name of adult stem cell given by Catherine Verfaillie, existing in bone marrow, can differentiate into cells with characteristics of mesodermal, neuroectodermal, and endodermal lineages in vitro at the single-cell level. MAPC can also contribute to most cell types when injected into the blastocyst. Adult stem cell differentiation implies that different cell lineages are derived from a single initial cell; all differentiated cell types are functional in vitro and in vivo; and engraftment is robust and persistent in the physiological and pathological situations. The possible mechanisms may underlie the differentiation: various tissue-specific stem cells are present in different organs; adult stem cells would be reprogrammed when removed from their usual microenvironment and introduced into a different niche that imparts signals to activate a novel genetic program needed for the new cell fate. And true multi-potential stem cells persist in postnatal life. In the future, multi-potent adult stem cells might then be used for therapies of degenerative or genetic disorders of multiple different organs.
Adult Stem Cells ; cytology ; Cell Differentiation ; Humans ; Multipotent Stem Cells ; cytology ; Stem Cell Transplantation

Spermatogonial stem cells (SSCs) are germline stem cells located along the basement membrane of seminiferous tubules in testes. Recently, SSCs were shown to be reprogrammed into multipotent SSCs (mSSCs). However, both the key factors and biological networks underlying this reprogramming remain elusive. Here, we present transcriptional regulatory networks (TRNs) that control cellular processes related to the SSC-to-mSSC reprogramming. Previously, we established intermediate SSCs (iSSCs) undergoing the transition to mSSCs and generated gene expression profiles of SSCs, iSSCs and mSSCs. By comparing these profiles, we identified 2643 genes that were up-regulated during the reprogramming process and 15 key transcription factors (TFs) that regulate these genes. Using the TF-target relationships, we developed TRNs describing how these TFs regulate three pluripotency-related processes (cell proliferation, stem cell maintenance and epigenetic regulation) during the reprogramming. The TRNs showed that 4 of the 15 TFs (Oct4/Pou5f1, Cux1, Zfp143 and E2f4) regulated cell proliferation during the early stages of reprogramming, whereas 11 TFs (Oct4/Pou5f1, Foxm1, Cux1, Zfp143, Trp53, E2f4, Esrrb, Nfyb, Nanog, Sox2 and Klf4) regulated the three pluripotency-related processes during the late stages of reprogramming. Our TRNs provide a model for the temporally coordinated transcriptional regulation of pluripotency-related processes during the SSC-to-mSSC reprogramming, which can be further tested in detailed functional studies.
Basement Membrane ; Cell Proliferation ; Epigenomics ; Multipotent Stem Cells* ; Seminiferous Tubules ; Stem Cells* ; Testis ; Transcription Factors ; Transcriptome

Abstract　　Hematopoietic stem cells are able to self-renewal and differentiate to all blood lineages. With the development of new technologies, recent studies have proposed the revised versions of hematopoiesis. In the classical model of hematopoietic differentiation, HSCs were located at the apex of hematopoietic hierarchy. During differentiation process, HSCs progressively lose self-renewal potential to be commited to progenitors with restricted differentiation potential. For instance, HSCs first give rise to multipotent progenitor cells, then produce bipotent and unipotent progenitors, and finally differentiate to mature blood cells. For the differentiation of megakaryocytes, common myeloid progenitors derived from HSCs give rise to megakaryocyte-erythrocyte progenitors and then develop to megakaryocytes. However, recent results show that megakaryocytes can be directly generated from HSCs without multipotent or bipotent phases. Alternatively, platelet-biased HSCs produce megakaryocyte progenitors. In this article, recent advances in the hematopoiesis and megakaryocyte differentiation pathway are reviewed.
Cell Differentiation ; Cell Lineage ; Hematopoiesis ; Hematopoietic Stem Cells ; Megakaryocytes ; Multipotent Stem Cells

Mesenchymal stem cells (MSCs) represent a heterogeneous group of multipotent stem cells that could be found in various somatic tissues. MSCs are defined by molecular and functional features including spindle-shape morphology, adherence to plastic surfaces, expression of specific surface markers and differentiation potential to chondrocytes, adipocytes and osteocytes. The surface markers were proposed to affect the differentiation potential of MSCs by a limited number of studies. Endoglin (CD105) is defined to be a significant marker for osteogenic and chondrogenic differentiation ability of MSCs. Low CD105 expression is associated with increased osteogenic potential while high CD105 expression is correlated with strong chondrogenic potential. Myrtucommulone-A (MC-A) is an active compound with various biological effects on different cell types but its effect on MSC differentiation has not been described yet. In the present study we aimed at investigating the longterm effects of MC-A on hMSCs. MC-A-treatment reduced CD105 expression in distinct human mesenchymal stem cell (hMSC) lines and gave rise to CD105(low) population but did not change CD44, CD90 or CD73 expression. The decrease in CD105 expression reduced the chondrogenic potential of hMSCs subsequently while adipogenic or osteogenic differentiation was not affected dramatically. MC-A-treatment also suppressed the NF-κB p65 activation which might be responsible for the reduced chondrogenic potential. Our findings suggest thatMC-Acould be used to enrichCD105(low)hMSCs without the need for cell sorting or changing culture conditions which could be utilised in targeted differentiation studies.
Adipocytes ; Chondrocytes ; Humans ; Mesenchymal Stromal Cells* ; Multipotent Stem Cells ; Osteocytes ; Plastics

Adult stem cells are drawing more and more attention due to the potential application in degenerative medicine without posing any moral problem. There is growing evidence showing that the human amnion contains various types of adult stem cell. Since amniotic tissue is readily available, it has the potential to be an important source of regenerative medicine material. In this study we tried to find multipotent adult stem cells in human amnion. We isolated stem cells from amniotic mesenchymal cells by limiting dilution assay. Similar to bone marrow derived mesenchymal stem cells, these cells displayed a fibroblast like appearance. They were positive for CD105, CD29, CD44, negative for haematopoietic (GlyA, CD31, CD34, CD45) and epithelial cell (pan-CK) markers. These stem cells had the potential to differentiate not only into osteogenic, adipogenic and endothelial lineages, but also hepatocyte-like cells and neural cells at the single-cell level depending on the culture conditions. They had the capacity for self-renewal and multilineage differentiation even after being expanded for more than 30 population doublings in vitro. So they may be an ideal stem cell source for inherited or degenerative diseases treatment.
Adult Stem Cells ; cytology ; Amnion ; cytology ; Cell Differentiation ; physiology ; Humans ; Mesenchymal Stromal Cells ; cytology ; Multipotent Stem Cells ; cytology

Essential thrombocythemia in childhood is a rare clonal myeloproliferative disorder in the multipotent stem cell origin and is associated with an increased risk of thrombohemorrhagic complications. The one of diagnostic criteria is a platelet count of more than 600,000/mm3. We diagnosed this disease in 8 year old boy incidentally and treated with hydroxyurea. We report a case of essential thrombocythemia to summarize the current trends in the diagnosis and management with a brief review of related literatures.
Child ; Diagnosis ; Humans ; Hydroxyurea ; Male ; Multipotent Stem Cells ; Myeloproliferative Disorders ; Platelet Count ; Thrombocythemia, Essential*

The aim of this study was to assess the involvement of multipotential progenitor cells in the pathogenesis of Mooren's ulcer using immunohistochemical staining techniques. Tissue specimens were collected from 3 Mooren's ulcer patients who underwent lamellar keratectomy. Immunohistochemical staining patterns were analyzed using antibodies: CD34, c-kit, STRO-1, CD45RO, VEGF and alpha-SMA. Strong positive CD34, c-kit and STRO-1 cells were revealed in Mooren's ulcer specimens, especially in the superficial stroma. A few weakly expressed CD34 stroma cells were seen in normal limbal cornea but no immunoreactivity for c-kit and STRO-1 could be found. CD45RO positive T cells were found to have infiltrated in Mooren's ulcer. The immunostaining pattern of VEGF and yen a- SMA was closely correlated with the degree of expression and the number of CD34 positive cells. Bone marrow-derived multipotential progenitor cells may be involved in the pathogenesis of Mooren's ulcer by synergizing with other factors to amplify autoimmune destructive reactions and to contribute to the regeneration process. Specific therapeutic strategies that target the role of these cells in the disease are warranted.
Cornea/*pathology ; Corneal Ulcer/*pathology ; Hematopoietic Stem Cells/*pathology ; Humans ; Multipotent Stem Cells/*pathology ; Research Support, Non-U.S. Gov't

OBJECTIVETo investigate the possibility of marrow derived multipotent adult progenitor cells (MAPCs) differentiating into hepatocytes by co-culturing with human hepatocyte line L02, and to evaluate the potential use of MAPCs in tissue-engineering either experimentally or clinically.

METHODS(1) Co-culturing without cell-to-cell contact: MAPCs and L02 hepatocytes were spread on coverslips separately (both with a cell density of 1x10(5)/ml), and then they were put in a culture dish (10 cm). The expressions of Alb, AFP, CK18, and CK19 in MAPCs were detected by immunocytochemistry at different time points. A separate culture of L02 hepatocytes served as a positive control and a separate culture of MAPCs served as a negative control. (2) Co-culturing with cell-to-cell contact: MAPCs labeled with CFSE were mixed with L02 hepatocytes (both with a cell density of 1x10(4)/ml), and then the mixed cells were seeded on specific dishes for detection by laser scanning confocal microscope (LSCM). Five days later, the cells were double-stained with SABC-Cy3. The expressions of Alb, AFP, CK18 in MAPCs were observed under LSCM. Similarly, separately cultured L02 hepatocytes served as a positive control and separately cultured MAPCs served as a negative control.

RESULTS(1) Results of co-culturing without cell-to-cell contact: On the first day, the MAPCs expressed a high level of AFP. Then AFP expression tapered daily and there was hardly any expression of AFP on day 7. The expression of Alb was very weak on day 1, but increased significantly by day 3, reached its peak on day 5, and still maintained a high level on day 7. The initial expression of CK18 appeared on day 5 and reached a higher level on day 7. The expression of CK19 was always negative. The positive control cells had a high expression of Alb and CK18, while there was a weak expression of AFP and a negative expression of CK19. The negative control cells had no expressions for the four markers. (2) Results of co-culturing with cell-to-cell contact: On day 5, there were three colors of fluorescence under LSCM: yellow cells were MAPCs differentiating into hepatocytes; green cells were undifferentiated MAPCs; red cells were L02 hepatocytes. The result showed that Alb and CK18 were expressed in many cells and AFP appeared in only a few cells.

CONCLUSIONHuman MAPCs can be induced to differentiate into mature hepatocyte-like cells by co-culturing with L02 hepatocytes, either with or without cell-to-cell contact, but the former way may be more effective.

Bone Marrow Cells ; cytology ; Cell Differentiation ; Cells, Cultured ; Coculture Techniques ; Hepatocytes ; cytology ; Humans ; Multipotent Stem Cells ; cytology

Neural stem cells are multipotent stem cells that can differentiate into neurons and glial cells. Neural stem cells are found in not only developing nervous system but some restricted regions in adult brain. Here, we presented an effective method that allows a long-term preservation of neural stem cells without losing multipotency. First, we isolated neural stem cells from the developing forebrain of nestin-EGFP transgenic mice carrying green fluorescence protein (GFP) driven by nestin promoter and enhancer. Primary neurospheres isolated from these mice highly expressed GFP. The expression of GFP in neurospheres was sustained for several passages. In order to investigate the effect of freezing on the stem cell properties, we cryopreserved the primary neurospheres for 2 wks in liquid nitrogen. GFP expression pattern as well as differentiation potential of the secondary neurosphere formed after cryopreservation were not that different from those of the primary neurosphere formed before cryopreservation. When the same cryopreservation method was applied to neural stem cells isolated from human fetal brain (gestation 13 ~15 wks), the expression of nestin, a stem cell marker, and differentiation patterns were not changed after cryopreservation. We also performed isolation of neural stem cells from long-term cryopreserved human fetal brain tissues. The neurospheres were successfully formed and showed similar differention properties with neurospheres isolated from fresh brain tissue. In addition, we demonstrated multipotentiality of neural stem cells was not changed with the duration of cryopreservation of brain tissue, suggesting the self renewality and multipotentiality of neural stem cells were not affected by long-term cryopreservation, The present results provide an useful information for the development of stem cell expansion which is essential factor in clinical application of stem cells.
Adult ; Animals ; Brain ; Cryopreservation* ; Fluorescence ; Freezing ; Humans ; Mice ; Mice, Transgenic ; Multipotent Stem Cells ; Nervous System ; Nestin ; Neural Stem Cells* ; Neuroglia ; Neurons ; Nitrogen ; Prosencephalon ; Stem Cells

BACKGROUND AND OBJECTIVES: Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated from umbilical cords and are therapeutically used because of their ability to differentiate into various types of cells, in addition to their immunosuppressive and anti-inflammatory properties. Fetal bovine serum (FBS), considered as the standard additive when isolating and culturing MSCs, has a major limitation related to its animal origin. Here, we employed a simple and economically efficient protocol to isolate MSCs from human umbilical cord tissues without using digestive enzymes and replacing FBS with umbilical cord blood serum (CBS). METHODS AND RESULTS: MSCs were isolated by culturing umbilical cord pieces in CBS or FBS supplemented media. Expansion and proliferation kinetics of cells isolated by explant method in the presence of either FBS or CBS were measured, with morphology and multi-differentiation potential of expanded cells characterized by flow cytometry, RT-PCR, and immunofluorescence. MSCs maintained morphology, immunophenotyping, multi-differentiation potential, and self-renewal ability, with better proliferation rates for cells cultured in CBS compared to FBS supplement media. CONCLUSIONS: We here present a simple, reliable and efficient method to isolate MSCs from umbilical cord tissues, where cells maintained proliferation, differentiation potential and immunophenotyping properties and could be efficiently expanded for clinical applications.
Animals ; Fetal Blood* ; Flow Cytometry ; Fluorescent Antibody Technique ; Humans* ; Immunophenotyping ; Kinetics ; Mesenchymal Stromal Cells* ; Methods* ; Multipotent Stem Cells ; Umbilical Cord*