PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Multipotent Stem Cells”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources

Olfactory horizontal basal cells demonstrate a conserved multipotent progenitor phenotype.

Stem cells of adult regenerative organs share a common goal but few established conserved mechanisms. Within the neural stem cell niche of the mouse olfactory epithelium, we identified a combination of extracellular matrix (ECM) receptors that regulate adhesion and mitosis in non-neural stem cells [intercellular adhesion molecule-1 (ICAM-1), beta1, beta4, and alpha-1, -3, and -6 integrins] and on horizontal basal cells (HBCs), candidate olfactory neuro-epithelial progenitors. Using ECM receptors as our guide, we recreated a defined microenvironment in vitro that mimics olfactory basal lamina and, when supplemented with epidermal growth factor, transforming growth factor alpha, and leukemia inhibitory factor, allows us to preferentially expand multiple clonal adherent colony phenotypes from individual ICAM-1+ and ICAM-1+/beta1 integrin+-selected HBCs. The most highly mitotic colony-forming HBCs demonstrate multipotency, spontaneously generating more ICAM-positive presumptive HBCs, a combination of olfactory neuroglial progenitors, and neurons of olfactory and potentially nonolfactory phenotypes. HBCs thus possess a conserved adhesion receptor expression profile similar to non-neural stem cells, preferential self-replication in an in vitro environment mimicking their in vivo niche, and contain subpopulations of cells that can produce multiple differentiated neuronal and glial progeny from within and beyond the olfactory system in vitro.

Animals↗

Mesenchymal stem cells and tissue engineering for orthopaedic surgery.

Bone marrow contains multipotent mesenchymal stem cells (MSCs) that can differentiate into different mesenchymal lineages whose end-stage cells fabricate bone, cartilage, tendon, fat, and other connective tissues. Our laboratory has been focusing on the purification, culture expansion, the in vivo and the in vitro characterization of MSCs and their descendants. Given the large number of MSCs that can be generated, we have explored their use in different pre-clinical models utilizing the therapeutic potentials of MSCs for musculoskeletal disorders. Using newly evolved tissue engineering principals, we have focus on the treatment of full thickness cartilage damage and, separately, bone non-union. The experimental results suggest the MSCs may provide a powerful therapeutic tool for the treatment of musculoskeletal disorders. Future efforts should be made to establish reliable and standardized full-scale clinical approaches using MSCs for orthopaedic surgery.

Animals↗

Genetic programs and responses of neural stem/progenitor cells during demyelination: potential insights into repair mechanisms in multiple sclerosis.

In recent years, it has become evident that the adult mammalian CNS contains a population of neural stem cells (NSCs) described as immature, undifferentiated, multipotent cells, that may be called upon for repair in neurodegenerative and demyelinating diseases. NSCs may give rise to oligodendrocyte progenitor cells (OPCs) and other myelinating cells. This article reviews recent progress in elucidating the genetic programs and dynamics of NSC and OPC proliferation, differentiation, and apoptosis, including the response to demyelination. Emerging knowledge of the molecules that may be involved in such responses may help in the design of future stem cell-based treatment of demyelinating diseases such as multiple sclerosis.

Animals↗

Common lymphoid progenitors, early B-lineage precursors, and IL-7: characterizing the trophic and instructive signals underlying early B cell development.

Precursors for B lymphocytes develop from semirestricted lymphoid progenitors in the bone marrow. Here we review current knowledge on the cellular stages underlying early B cell development from multipotent progenitor cells, and discuss the factors implicated in the regulation of this process. In particular, we will focus on the role of cytokine receptor signaling in early lymphocyte ontogeny and lymphoid lineage commitment, with an emphasis on the role of interleukin- 7 (IL-7) in early lymphocyte development within the bone marrow microenvironment. We will also discuss recent evidence that lymphocytes and subsets of dendritic cells develop from a common pathway, speculating that IL-7 may regulate cell fate decisions in multipotent B/dendritic cell precursors by driving these cells to differentiate into B-lineage-committed cells.

Animals↗

Stem cell biology and therapeutic applications.

PURPOSE OF REVIEW: Chronic diseases are common and deadly. Stem cell therapies have received intense interest for the repopulation of damaged or diseased tissues. A detailed understanding of the similarities and differences between embryonic stem cells and somatic stem cells will enhance our understanding of mechanisms of tissue repair or cellular augmentation. In addition, emerging technologies will be useful in the definition of the molecular regulation of the respective stem cell populations. RECENT FINDINGS: A number of postnatal tissues have a population of somatic stem cells, which function in the maintenance and repair of tissues. Using molecular technologies these somatic stem cell populations have been shown to be pluripotent when placed in a permissive environment. Recent studies have utilized emerging technologies to define a molecular signature of embryonic stem cells and selected somatic stem cell populations. These strategies will be useful for the definition of a molecular program that promotes a stem cell phenotype (i.e. stemness phenotype). SUMMARY: Recent studies suggest that embryonic and somatic stem cell populations hold promise as sources for tissue engineering. The use of cell biological and molecular technologies will enhance our understanding of embryonic and somatic stem cell populations and their molecular regulatory events that promote multipotentiation.

Germ Cells↗

Parity-induced mammary epithelial cells are multipotent and express cell surface markers associated with stem cells.

Parity-induced mammary epithelial cells (PI-MECs) are defined as a pregnancy hormone-responsive cell population that activates the promoter of late milk protein genes during the second half of pregnancy and lactation. However, unlike their terminally differentiated counterparts, these cells do not undergo programmed cell death during post-lactational remodeling of the gland. We previously demonstrated that upon transplantation into an epithelial-free mammary fat pad, PI-MECs exhibited two important features of multipotent mammary epithelial progenitors: a) self-renewal, and b) contribution to ductal and alveolar morphogenesis. In this new report, we introduce a new method to viably label PI-MECs. Using this methodology, we analyzed the requirement of ovarian hormones for the maintenance of this epithelial subtype in the involuted mammary gland. Furthermore, we examined the expression of putative stem cell markers and found that a portion of GFP-labeled PI-MECs were part of the CD24(+)/CD49f(high) mammary epithelial subtype, which has recently been suggested to contain multipotent stem cells. Subsequently, we demonstrated that isolated PI-MECs were able to form mammospheres in culture, and upon transplantation, these purified epithelial cells were capable of establishing a fully functional mammary gland. These observations suggest that PI-MECs contain multipotent progenitors that are able to self renew and generate diverse epithelial lineages present in the murine mammary gland.

Animals↗

Human neural stem cells genetically modified for brain repair in neurological disorders.

Existence of multipotent neural stem cells (NSC) has been known in developing or adult mammalian CNS, including humans. NSC have the capacity to grow indefinitely and have multipotent potential to differentiate into three major cell types of CNS, neurons, astrocytes and oligodendrocytes. Stable clonal lines of human NSC have recently been generated from the human fetal telencephalon using a retroviral vector encoding v-myc. One of the NSC lines, HB1.F3, carries normal human karyotype of 46XX and has the ability to self-renew, differentiate into cells of neuronal and glial lineages, and integrate into the damaged CNS loci upon transplantation into the brain of animal models of Parkinson disease, HD, stroke and mucopolysaccharidosis. F3 human NSC were genetically engineered to produce L-dihydroxyphenylalanine (L-DOPA) by double transfection with cDNA for tyrosine hydroxylase and guanosine triphosphate cylohydrolase-1, and transplantation of these cells in the brain of Parkinson disease model rats led to L-DOPA production and functional recovery. Proactively transplanted F3 human NSC in rat striatum, supported the survival of host striatal neurons against neuronal injury caused by 3-nitropro-pionic acid in rat model of HD. Intravenously introduced through the tail vein, F3 human NSC were found to migrate into ischemic lesion sites, differentiate into neurons and glial cells, and improve functional deficits in rat stroke models. These results indicate that human NSC should be an ideal vehicle for cell replacement and gene transfer therapy for patients with neurological diseases. In addition to immortalized human NSC, immortalized human bone marrow mesenchymal stem cell lines have been generated from human embryonic bone marrow issues with retroviral vectors encording v-myc or teromerase gene. These immortalized cell lines of human bone marrow mesenchymal stem cells differentiated into neurons/glial cells, bone, cartilage and adipose tissue when they were grown in selective inducing media. There is further need for investigation into the neurogenic potential of the human bone marrow stem cell lines and their utility in animal models of neurological diseases.

Brain↗

Multiple tumor types may originate from bone marrow-derived cells.

It was believed that tumors originated from the transformation of their tissue-specific stem cells. However, bone marrow-derived cells (BMDCs), which possess an unexpected degree of plasticity and often reside in other tissues, might also represent a potential source of malignancy. To study whether BMDCs play a role in the source of other tumors, BMDCs from mice were treated with 3-methycholanthrene until malignant transformation was achieved. Here we show that transformed BMDCs could form many tumor types, including epithelial tumors, neural tumors, muscular tumors, tumors of fibroblasts, blood vessel endothelial tumors, and tumors of poor differentiation in vivo. Moreover, a single transformed BMDC has the ability to self-renew, differentiate spontaneously into various types of tumor cells in vitro, express markers associated with multipotency, and form teratoma in vivo. These data suggest that multipotent cancer stem cells seemed to originate from transformed BMDCs. Conclusively, these findings reveal that BMDCs might be a source of many tumor types, even teratoma. In addition, multipotent cancer stem cells might originate from malignant transformed BMDCs.

Animals↗

Lymphocyte commitment during embryonic development, in the mouse.

Multipotent hematopoietic stem cells (HSC) differentiate into mature cells in the fetal liver (FL) during embryonic development, and in the bone marrow (BM) in adult animals. Multilineage differentiation is accomplished by the stepwise commitment of stem cells that sequentially loose differentiation potential. The characterization of the intermediate lymphoid precursors isolated from both hematopoietic sites suggests that, in FL, their potential of differentiation as well as their growth factor requirements are apparently less strict than in the BM. This could be the result of different commitment strategies at those sites: stochastic in the FL and instructive in the BM.

Animals↗

An epidermal neural crest stem cell (EPI-NCSC) molecular signature.

Here, we report the first transcriptome for mouse epidermal neural crest stem cells (EPI-NCSC, formerly eNCSCs). In addition, our study resolves conflicting opinions in the literature by showing that EPI-NCSC are distinct from other types of skin-resident stem cells/progenitors. Finally, with the three gene profiles, we have established a foundation and provide a valuable resource for future mouse NCSC research. EPI-NCSC represent a novel type of multipotent adult stem cell that originates from the embryonic neural crest and resides in the bulge of hair follicles. We performed gene profiling by LongSAGE (long serial analysis of gene expression) with mRNA from EPI-NCSC, embryonic NCSC, and in vitro differentiated embryonic neural crest progeny. We have identified important differentially expressed genes, including novel genes and disease genes. Furthermore, using stringent criteria, we have defined an NCSC molecular signature that consists of a panel of 19 genes and is representative of both EPI-NCSC and NCSC. EPI-NCSC have characteristics that combine advantages of embryonic and adult stem cells. Similar to embryonic stem cells, EPI-NCSC have a high degree of innate plasticity, they can be isolated at high levels of purity, and they can be expanded in vitro. Similar to other types of adult stem cell, EPI-NCSC are readily accessible by minimal invasive procedure. Multipotent adult mammalian stem cells are of great interest because of their potential value in future cell replacement therapy by autologous transplantation, which avoids graft rejection.

Animals↗

Identification of a primitive brain-derived neural stem cell population based on aldehyde dehydrogenase activity.

Stem cells are undifferentiated cells defined by their ability to self-renew and differentiate to progenitors and terminally differentiated cells. Stem cells have been isolated from almost all tissues, and an emerging idea is that they share common characteristics such as the presence of ATP-binding cassette transporter G2 and high telomerase and aldehyde dehydrogenase (ALDH) activity, raising the hypothesis of a set of universal stem cell markers. In the present study, we describe the isolation of primitive neural stem cells (NSCs) from adult and embryonic murine neurospheres and dissociated tissue, based on the expression of high levels of ALDH activity. Single-cell suspension was stained with a fluorescent ALDH substrate termed Aldefluor and then analyzed by flow cytometry. A population of cells with low side scatter (SSC(lo)) and bright ALDH (ALDH(br)) activity was isolated. SSC(lo)ALDH(br) cells are capable of self-renewal and are able to generate new neurospheres and neuroepithelial stem-like cells. Furthermore, these cells are multipotent, differentiating both in neurons and macroglia, as determined by immunocytochemistry and real-time reverse transcription-polymerase chain reaction analysis. To evaluate the engraftment potential of SSC(lo)ALDH(br) cells in vivo, we transplanted them into mouse brain. Donor-derived neurons with mature morphology were detected in the cortex and subcortical areas, demonstrating the capacity of this cell population to differentiate appropriately in vivo. The ALDH expression assay is an effective method for direct identification of NSCs, and improvement of the stem cell isolation protocol may be useful in the development of a cell-mediated therapeutic strategy for neurodegenerative diseases.

Aldehyde Dehydrogenase↗

Stem and progenitor cell-based therapy of the human central nervous system.

Multipotent neural stem cells, capable of giving rise to both neurons and glia, line the cerebral ventricles of all adult animals, including humans. In addition, distinct populations of nominally glial progenitor cells, which also have the capacity to generate several cell types, are dispersed throughout the subcortical white matter and cortex. A number of approaches have evolved for using neural progenitor cells in cell therapy. Four strategies are especially attractive for clinical translation: first, transplantation of oligodendrocyte progenitor cells as a means of treating the disorders of myelin; second, transplantation of phenotypically restricted neuronal progenitor cells to treat diseases of discrete loss of a single neuronal phenotype, such as Parkinson disease; third, implantation of mixed progenitor pools to treat diseases characterized by the loss of several discrete phenotypes, such as spinal cord injury; and fourth, mobilization of endogenous neural progenitor cells to restore neurons lost as a result of neurodegenerative diseases, in particular Huntington disease. Together, these may present the most compelling strategies and near-term disease targets for cell-based neurological therapy.

Central Nervous System Diseases↗

Efficient isolation and gene expression profiling of small numbers of neural crest stem cells and developing Schwann cells.

Schwann cells develop from multipotent neural crest stem cells and are important for neuronal survival, maintenance of axonal integrity, and myelination. We used transgenic mice expressing green fluorescent protein in a tissue-specific manner to isolate viable, pure populations of neural crest stem cells and developing Schwann cells, which are not readily accessible by microdissection. Starting with the minute amounts of RNA obtained, a two-round amplification procedure was used to achieve reproducible DNA array hybridizations. We validated our screening procedure by comparisons with the literature and by in situ hybridization. Stage-to-stage comparisons and hierarchical clustering for neural crest and five stages of Schwann cell development suggest a wealth of candidates for genes involved in stem cell regulation and in early Schwann cell development. The combination of methods applied in this study should be generally useful for isolating and profiling other stem cell and difficult to isolate cell populations.

Animals↗

Inhibitory effects of tumor necrosis factor on hematopoiesis seen in vitro are translated to increased numbers of both committed and multipotent progenitors in TNF-deficient mice.

OBJECTIVES: The effects of TNF deficiency on myelopoiesis were evaluated in long-term (LTBMC) and short-term bone marrow cultures (STBMC) and compared to hematopoietic activity in vivo in TNF-deficient mice. METHODS: LTBMC and STBMC were established from bone marrow of TNF-deficient mice in the presence or absence of soluble TNF. Total cell production was measured over time, as well as the number of colony-forming units in culture (CFU-C). Morphology of nonadherent (NA) cells in LTBMC was assessed after 10 weeks. Bone marrow cells (BMC) and peripheral blood (PB) cells were used to determine lineage distribution within the hematopoietic system. BMC were sorted to obtain Lin(-)c-kit(+)Sca-1- and Lin(-)c-kit(+)Sca-1+ cells, which were plated in semisolid media to determine CFU-C numbers or injected into irradiated recipients to determine colony formation in the spleen (CFU-S). RESULTS: TNF-deficient LTBMC and STBMC show increased proliferative capacity, which can be inhibited by exogenous TNF to wild-type levels. Morphological analysis of NA cells from TNF-deficient LTBMC revealed increased numbers of cells at early stages of granulocytic differentiation (myeloblasts/promyelocytes) paralleled by a sharp decrease in the number of terminally differentiated polymorphonuclear neutrophils. Slightly elevated numbers of leukocytes, mainly neutrophils, were detected in PB of TNF-deficient mice. In bone marrow of TNF-deficient mice a significant increase in the number of both CFU-GM within Lin(-)c-kit(+)Sca-1- population and CFU-S within Lin(-)c-kit(+)Sca-1+ population was observed. CONCLUSIONS: TNF has inhibitory effects on granulocyte-macrophage progenitors in vitro and on committed and primitive hematopoietic progenitors in vivo. However, in adult organism TNF deficiency is mostly compensated and controlled.

Age Factors↗

Multipotent flk-1+ cardiovascular progenitor cells give rise to the cardiomyocyte, endothelial, and vascular smooth muscle lineages.

Cell-tracing studies in the mouse indicate that the cardiac lineage arises from a population that expresses the vascular endothelial growth factor receptor 2 (VEGFR2, Flk-1), suggesting that it may develop from a progenitor with vascular potential. Using the embryonic stem (ES) cell differentiation model, we have identified a cardiovascular progenitor based on the temporal expression of the primitive streak (PS) marker brachyury and Flk-1. Comparable progenitors could also be isolated from head-fold stage embryos. When cultured with cytokines known to function during cardiogenesis, individual cardiovascular progenitors generated colonies that displayed cardiomyocyte, endothelial, and vascular smooth muscle (VSM) potential. Isolation and characterization of this previously unidentified population suggests that the mammalian cardiovascular system develops from multipotential progenitors.

Animals↗

Stem cells: a minireview.

The identification of adult-derived stem cells which maintain plasticity throughout the course of a lifetime, has transformed the field of stem cell biology. Bone marrow derived hematopoietic stem cells (HSC) are the most well-characterized population of these multipotential cells. First identified for their ability to reconstitute blood lineages and rescue lethally irradiated hosts, these cells have also been shown to differentiate and integrate into skeletal muscle, cardiac myocytes, vascular endothelium, liver, and brain tissue. Various populations of HSC are being studied, exploiting cell surface marker expression, such as Sca-1, c-kit, CD34, and lin; as well as the abilityto efflux the vital dye Hoecsht 33342. Detection of engrafted donor derived cells into various tissue types in vivo is a laborious process and may involve detection of beta-galactosidase via colorimetric reaction or antibody labeling or green fluorescent protein (GFP) via fluorescence microscopy, as well as in situ hybridization to detect the Y-chromosome. Using these techniques, the search has begun for tissue specific stem cells capable of host tissue regeneration, self renewal, and transdifferentiation. Caution is urged when interpreting these types of experiments because although they are stimulating, limitations of the technologies may provide misleading results.

Animals↗

SDF-1alpha-induced intracellular calcium transient involves Rho GTPase signalling and is required for migration of hematopoietic progenitor cells.

Signalling through the chemokine stromal derived factor (SDF)-1alpha and its receptor CXCR4 has been recognized as a key event in the migratory response of hematopoietic stem and progenitor cells (HPC). Small GTPases of the Rho/Rac family might be involved in SDF-1alpha signalling at several different levels. In the present study we report that two toxins from Clostridium species which inhibit the small GTPase Rho suppressed SDF-1alpha-induced generation of intracellular calcium transients in HPC. Chelation of intracellular Ca(2+) with BAPTA or depletion of intracellular Ca(2+) stores with thapsigargin demonstrated that calcium transients are essential for SDF-1alpha-induced chemotactic migration of HPC. Furthermore, transplantation of HPC pretreated with Ca(2+) flux inhibitors into mice revealed a suppression of HPC homing to the bone marrow and increased levels of cells remaining in the bloodstream or circulating to the spleen. Our data indicate that the small GTPase Rho is required for the induction of Ca(2+) transients in HPC, which in turn are necessary for the coordinated migratory response of HPC both in vitro and in vivo.

Animals↗