Human Stem Cell Therapy Research Articles

Potential Advance in Human Hematopoietic Stem Cell Therapy

Hematopoietic stem cell (HSC) transplantation does not save as many lives as it could: An insufficient number of HSCs in allogeneic HSC grafts and cord

A novel serum-free medium for the expansion of human mesenchymal stem cells

IntroductionHuman multipotent mesenchymal stem cell (MSC) therapies are being tested clinically for a variety of disorders, including Crohn's disease, multiple sclerosis, graft-versus-host disease, type 1 diabetes, bone fractures, and cartilage defects. However, despite the remarkable clinical advancements in this field, most applications still use traditional culture media containing fetal bovine serum. The ill-defined and highly variable nature of traditional culture media remains a challenge, hampering both the basic and clinical human MSC research fields. To date, no reliable serum-free medium for human MSCs has been available.MethodsIn this study, we developed and tested a serum-free growth medium on human bone marrow-derived MSCs through the investigation of multiple parameters including primary cell isolation, multipassage expansion, mesoderm differentiation, cellular phenotype, and gene-expression analysis.ResultsSimilar to that achieved with traditional culture medium, human MSCs expanded in serum-free medium supplemented with recombinant human platelet-derived growth factor-BB (PDGF-BB), basic fibroblast growth factor (bFGF), and transforming growth factor (TGF)-β1 showed extensive propagation with retained phenotypic, differentiation, and colony-forming unit potential. To monitor global gene expression, the transcriptomes of bone marrow-derived MSCs expanded under serum-free and serum-containing conditions were compared, revealing similar expression profiles. In addition, the described serum-free culture medium supported the isolation of human MSCs from primary human marrow aspirate with continual propagation.ConclusionsAlthough the described serum-free MSC culture medium is not free of xenogeneic components, this medium provides a substitute for serum-containing medium for research applications, setting the stage for future clinical applications.

Human Cord Blood Stem Cell Therapy for Treatment of Stress Urinary Incontinence

Our objective in this study was to evaluate the safety and efficacy of transurethral cord blood stem cell injection for treatment of stress urinary incontinence in women. Between July 2005 and July 2006, 39 women underwent transurethral umbilical cord blood stem cell injection performed by one operator at a single hospital. All patients had stress urinary incontinence. The patients were evaluated 1, 3, and 12 months postoperatively. No postoperative complications were observed. 28 patients (77.8%) were more than 50% satisfied according to the Patient's Satisfaction results after 1 month, 29 patients (83%) were more than 50% satisfied according to the Patient's Satisfaction results after 3 months, and 26 (72.2%) continuously showed more than 50% improvement after 12 months. Intrinsic sphincter deficiency and mixed stress incontinency improved in the ten patients evaluated by urodynamic study. Our results suggest that transurethral umbilical cord blood stem cell injection is an effective treatment for women with all types of stress urinary incontinence.

Persistent competition among stem cells and their daughters in theDrosophilaovary germline niche

Cell competition is a short-range cell-cell interaction leading to the proliferation of winner cells at the expense of losers, although either cell type shows normal growth in homotypic environments. Drosophila Myc (dMyc; Dm-FlyBase) is a potent inducer of cell competition in wing epithelia, but its role in the ovary germline stem cell niche is unknown. Here, we show that germline stem cells (GSCs) with relative lower levels of dMyc are replaced by GSCs with higher levels of dMyc. By contrast, dMyc-overexpressing GSCs outcompete wild-type stem cells without affecting total stem cell numbers. We also provide evidence for a naturally occurring cell competition border formed by high dMyc-expressing stem cells and low dMyc-expressing progeny, which may facilitate the concentration of the niche-provided self-renewal factor BMP/Dpp in metabolically active high dMyc stem cells. Genetic manipulations that impose uniform dMyc levels across the germline produce an extended Dpp signaling domain and cause uncoordinated differentiation events. We propose that dMyc-induced competition plays a dual role in regulating optimal stem cell pools and sharp differentiation boundaries, but is potentially harmful in the case of emerging dmyc duplications that facilitate niche occupancy by pre-cancerous stem cells. Moreover, competitive interactions among stem cells may be relevant for the successful application of stem cell therapies in humans.

FDA scrutinizes human stem cell therapies

FDA scrutinizes human stem cell therapies

NerveCenter: (1) Genome scans get personal with online consumer services (2) Trial of human stem cell therapy for spinal cord injury to begin this summer

NerveCenter: (1) Genome scans get personal with online consumer services (2) Trial of human stem cell therapy for spinal cord injury to begin this summer

Augmentation of Vasculogenesis by Injected Human Hematopoietic Stem Cells in Response to Ischemia Follows Early Activation of Innate Immune Response.

The immunocompromised NOD.SCID murine model of hindlimb ischemia has been used extensively to test in vivo the impact of human hematopoietic stem cell (HSC) therapy on neovascularization. Although NOD.SCID lack T and B cell adaptive immune responses, innate responses are intact. We utilized this model to test the hypothesis whether injection of human HSC following femoral ligation impacts neovascularization within the ischemic bed and whether early murine innate cellular responses differ in animals treated with HSC. NOD.SCID underwent femoral ligation and were divided into 3 study groups: controls (media alone), human HSC (CD133+ HSC selected from umbilical cord blood-UCB), or human peripheral blood mononuclear cells. Laser Doppler studies day +28 after femoral ligation showed significantly improved blood flow ratio in animals treated with human HSC vs. controls, 0.55 ± 0.06 (n=9) and 0.37 ± 0.03 (n=12, p<0.05) respectfully. Histology day +42 confirmed increased capillary density in animals treated with human HSC (320±18 cells/mm2) when compared to control animals (131±.6.9 cells/mm2; p<0.0001). Gene expression microarrays (Affymetrix Murine GeneChip 430 2.0) of RNA extracted from tissues harvested from the ischemic limbs 3 days following femoral ligation and injection of cells (n=3 each experimental group) comparing control mice to those receiving human HSC vs. controls revealed 414 genes with 2-fold or greater change. Included in these were genes regulating innate immunity: monocyte chemoattractant protein-5 precursor (MCP-5), CCL11, CXCL5, CXCL9, IL4 receptor, CXCL10, CCL5 and toll-like receptor 3 (TLR3). Of note large expression differences were noted comparing animals treated with human HSC including kruppel-like factor 15 (4 fold increase), IL6 receptor (3.25 fold increase), cyclin A2 (4.25 fold decrease). No significant increases in genes regulating angiogenesis were noted comparing animals treated with human HSC vs controls, including VEGF, angiopoietin, or bFGF. In summary, NOD.SCID treated with human HSC after femoral ligation demonstate significantly improved capillary density and blood flow recovery at later time points (day 28–42). Proteins regulating innate immunity are significantly higher at early time points in animals treated with human HSC suggesting an important role for inflammatory responses leading to augmentation of vasculogenesis after acute vascular injury.

Characterization of an immunodeficient mouse model of mucopolysaccharidosis type I suitable for preclinical testing of human stem cell and gene therapy

Mucopolysaccharidosis type I (MPS-I or Hurler syndrome) is an inherited deficiency of the lysosomal glycosaminoglycan (GAG)-degrading enzyme α- l-iduronidase (IDUA) in which GAG accumulation causes progressive multi-system dysfunction and death. Early allogeneic hematopoietic stem cell transplantation (HSCT) ameliorates clinical features and extends life but is not available to all patients, and inadequately corrects its most devastating features including mental retardation and skeletal deformities. To test novel therapies, we characterized an immunodeficient MPS-I mouse model less likely to develop immune reactions to transplanted human or gene-corrected cells or secreted IDUA. In the liver, spleen, heart, lung, kidney and brain of NOD/SCID/MPS-I mice IDUA was undetectable, and reduced to half in heterozygotes. MPS-I mice developed marked GAG accumulation (3–38-fold) in these organs. Neuropathological examination showed GM 3 ganglioside accumulation in the striatum, cerebral peduncles, cerebellum and ventral brainstem of MPS-I mice. Urinary GAG excretion (6.5-fold higher in MPS-I mice) provided a non-invasive and reliable method suitable for serially following the biochemical efficacy of therapeutic interventions. We identified and validated using rigorous biostatistical methods, a highly reproducible method for evaluating sensorimotor function and motor skills development. This Rotarod test revealed marked abnormalities in sensorimotor integration involving the cerebellum, striatum, proprioceptive pathways, motor cortex, and in acquisition of motor coordination. NOD/SCID/MPS-I mice exhibit many of the clinical, skeletal, pathological and behavioral abnormalities of human MPS-I, and provide an extremely suitable animal model for assessing the systemic and neurological effects of human stem cell transplantation and gene therapeutic approaches, using the above techniques to measure efficacy.

Getting the right stuff: Controlling neural stem cell state and fate in vivo and in vitro with biomaterials

Stem cell therapy holds great promises in medical treatment by, e.g., replacing lost cells, re-constitute healthy cell populations and also in the use of stem cells as vehicles for factor and gene delivery. Embryonic stem cells have rightfully attracted a large interest due to their proven capacity of differentiating into any cell type in the embryo in vivo. Tissue-specific stem cells are however already in use in medical practice, and recently the first systematic medical trials involving human neural stem cell (NSC) therapy have been launched. There are yet many obstacles to overcome and procedures to improve. To ensure progress in the medical use of stem cells increased basic knowledge of the molecular mechanisms that govern stem cell characteristics is necessary. Here we provide a review of the literature on NSCs in various aspects of cell therapy, with the main focus on the potential of using biomaterials to control NSC characteristics, differentiation, and delivery. We summarize results from studies on the characteristics of endogenous and transplanted NSCs in rodent models of neurological and cancer diseases, and highlight recent advancements in polymer compatibility and applicability in regulating NSC state and fate. We suggest that the development of specially designed polymers, such as hydrogels, is a crucial issue to improve the outcome of stem cell therapy in the central nervous system.

Therapie mit embryonalen Stammzellen – wie steht die Öffentlichkeit zu den ethischen Fragen?

This work discusses the manner in which the public has dealt with the ethical questions about human embryonic stem cell research. It argues that the public is not a homogenous entity, but rather consists of a number of "different publics", which at different points of the debate have discussed different aspects and different questions of this therapeutic proposal. It understands the development of human stem cell therapy not as a result of the activity of an isolated science, acting independently of society. In the contrary it considers it as a co-production of science with the different social actors, which participate in the political, ethical, and legal processes. Therefore the question if ethics is ahead or lags behind the developments in medical research becomes obsolete. Ethics is on one side the result of the effort to handle the results of biomedical research in a manner which is adequate for society at large on the other side it also influences the scientific-technological development through its own assessment.

Characterization of an Immunodeficient Mucopolysaccharidosis Type I (MPS-I) Mouse Model Suitable for Preclinical Testing of Human Stem Cell and Gene Therapy.

Mucopolysaccharidosis type I (MPS-I; Hurler syndrome) is an inborn metabolic disorder due to lack of the lysosomal glycosaminoglycan (GAG)-degrading enzyme alpha-L-iduronidase (IDUA). The resulting GAG accumulation causes progressive multi-system dysfunction and death in the first decade. We recently identified structural abnormalities in the accumulated GAGs that lead to defective heparin-binding cytokine signaling in MPS-I (Pan C et al, Blood 2005 in press: DOI 10.1182/blood-2005-02-0657), which may constitute a mechanism responsible for the diverse clinical manifestations of MPS-I and related mucopolysaccharidoses. Allogeneic hematopoietic stem cell transplantation (HSCT), if performed early in the disease, ameliorates many clinical features and extends life. However, HSCT is not available to all patients, and also does not adequately correct some of the most devastating features of MPS-I including mental retardation and skeletal deformities. Therefore, novel cellular, enzyme replacement and gene therapy approaches need to be developed for MPS-I. Such therapeutic strategies will best be tested in an immunodeficient host which is less likely to develop immune reactions to transplanted human or gene-corrected cells or their secreted IDUA enzyme. We have bred and characterized a homozygous immunodeficient MPS-I mouse (developed as a heterozygous MPS-I mouse on a NOD/SCID background by Jackson Labs) that is well suited for examining the efficacy of such therapeutic approaches. The phenotype of homozygous NOD/SCID/MPS-I mice closely mimicked the clinical features of human MPS-I including coarsening of facial features, skeletal deformities and diverse behavioral abnormalities. IDUA enzyme was completely undetectable in the liver, spleen, heart, lung, kidney and brain of homozygous animals (P<0.001) and was reduced to approximately 50% in heterozygous animals. Homozygous animals developed marked GAG accumulation (3 to 25 fold) in the same organs (P=0.03 to P<0.0001). Neuropathological examination showed accumulation of GM3 gangliosides in the cerebral peduncles, cerebellum and ventral brainstem of homozygous mice. Importantly, measurement of urinary GAG excretion (5-fold higher in homozygous animals; P<0.003) provided a non-invasive and reliable method that can be used to serially follow the biochemical efficacy of therapeutic interventions. We also identified and validated using rigorous biostatistical methods, a highly reproducible method for evaluating sensorimotor function and learning in this mouse model. This Rotarod Test revealed marked abnormalities in sensorimotor integration involving the cerebellum, niagro-striatal and proprioceptive pathways and motor cortex, as well as in learning. We believe that NOD/SCID/MPS-I mice will provide an extremely suitable animal model for assessing the systemic as well as neurological effects of human stem cell transplantation and gene therapeutic approaches, using the above techniques to measure efficacy. We have started using this model to assess the effect of intra-cerebroventricular implantation of human stem cells on the biochemical, pathological and behavioral abnormalities identified. Similar strategies may be invaluable for developing and studying animal models of other MPSs and related diseases.

How does human stem cell therapy influence gene expression after liver injury?: Microarray evaluation on a rat model

Background Tissue homeostasis is guaranteed by stem proliferating reserve, depending on dynamic changes in gene expression. A high plasticity is shown by the haematopoietic stem cells, potential source for liver regeneration. Aim We aimed to evaluate the gene expression modifications induced by human haematopoietic stem cell therapy after liver injury in rats. Subjects Rats were sorted as follows: (A) human-haematopoietic stem cell injection after allyl alcohol liver damage; (B) only haematopoietic stem cell injection; (C) only allyl alcohol injection; and (D) sacrifice without any treatment. Methods Livers, spleens and bone marrows were analysed with flow-cytometry. Livers were also studied by reverse-transcription PCR, histology, immunohistochemistry and microarray analysis; selected genes were confirmed by real-time PCR. Results In subset A, haematopoietic stem cells were selectively recruited by liver, with respect to the group B, and they improved the liver regeneration process compared to group C. As regards microarrays, haematopoietic stem cell infusion upregulates 265 genes and downregulates 149 genes. Differentially regulated genes belong to a broad range of functional pathways, including proliferation, differentiation, adhesion/migration and transcripts related to oval-cell activation. Real-time PCR validated array results. Conclusions Our study confirmed the capacity of haematopoietic stem cells to contribute to liver regeneration. Moreover, microarray analysis led to the identification of genes whose regulation strongly correlates with a more efficient process of liver repair after haematopoietic stem cell injection.

243. Transplantation of Neonatal NOD/SCID/MPSVII Mice with Human Mesenchymal Stem Cells

In this study we assessed the transfer and expression of the gene for beta-glucuronidase (GUSB) into multiple tissues by infusing normal human mesenchymal stem cells (MSC) into unconditioned neonatal NOD/SCID/MPSVII (GUSB null) mice. In this study, pups were transplanted before 3 days of age using the facial vein injection strategy. We hypothesized that neonatal pups would provide a rapidly growing environment for engraftment and expansion of transplanted normal human MSC into different tissues. The Sands laboratory has used the MPSVII mouse for many years to study disease progression, including neural defects, and to study correction of the disease by gene replacement therapies. In order to study cellular therapies using normal human cells, the murine MPSVII mutation was backcrossed for ten generations onto the NOD/SCID strain. Human umbilical cord blood CD34+ cells engraft in the resultant NOD/SCID/GUSB null strain to levels of 86% marrow replacement, similar to the NOD/SCID parent (Hofling 2004). The tissues of the mice can be homogenized and subjected to a GUSB enzyme assay, and plotted against a standard curve composed of normal human and GUSB null mouse cells, to quantitate the percentage of human cells that had been residing in the tissue of interest at the time of harvest. There is also a FACS|[ndash]|based assay to detect levels of the GUSB protein, and to allow sorting of donor-derived cells from any tissue after transplantation. The aspect of the NOD/SCID/GUSB null strain that makes it so particularly well suited for the study of human stem cell therapy is the clear-cut enzymatic stain for normal, GUSB positive human cells transplanted into the mice. On tissue slides prepared from mice that had been transplanted at birth with human mesenchymal stem cells, the histochemical stain for GUSB revealed normal cells in multiple tissues. Almost all tissues surveyed (N=19) demonstrated the presence of human MSC by staining for GUSB. The stain is quite specific, and although the released enzyme can be taken up by neighboring cells, it appears to be in very low abundance or, more likely, in a processed form where it is no longer detectable by the histochemical analysis. Thus, the individual transplanted human cells stand out vividly against the background murine tissues. In summary, the use of the NOD/SCID/MPSVII neonatal injection model has allowed accurate tracking and quantitation of human MSC into multiple tissues of mice injected by facial vein within three days of birth. This study may set the stage for neonatal gene/cell therapy for newborns with lysosomal storage diseases.

Clonagem e células-tronco

APESAR do muito que se tem discutido, ainda existe muita confusão em relação aos conceitos de clonagem (reprodutiva e terapêutica) , células-tronco ( embrionárias e não embrionárias) e terapia celular bem como isso pode afetar as nossas vidas. Portanto a proposta desse artigo é o de tentar definir esses conceitos e expressar a minha posição sobre aspectos éticos não só como cientista mas também como representante de inúmeras famílias que vêem nessa nova tecnologia uma esperança futura de cura para inúmeras doenças neurodegenerativas , muitas vezes letais ou gravemente incapacitantes.

Cellules souches et thérapie cellulaire. Contribution au débat éthique

Divergent and sometimes conflicting positions with respect to human stem cells and cell therapy do not merely reflect disagreement among scientists and conflicts of interest. They attest the ethical tension resulting from recent progress in understanding the earliest stages of development of the human being that can be observed in vitro. Can the extremely potent notion of the human person starting with conception apply to the very first stage of artificial in vitro fertilisation and disregard the fact that to be a real substitute for natural conception, implantation in the uterus that enables the oocyte to nest and a new human being to develop must also be included? Several arguments are presented that plead in favour of making a clear distinction between the status of in vitro cells obtained by artificial fertilisation and that of the embryo, which becomes a developing human being from the moment it implants in the endometrium of the uterus. This subject could have remained in the sphere of the individual conscience, but it has now become a theme for social debate! The revision of the French 1994 so-called Bioethics Laws, which was recently approved on first reading on 22 January 2002, authorises research on spare embryos from in vitro fertilisation under certain conditions. However, for the sole reason that there is a risk of opening the door wide to reproductive cloning, which is unanimously rejected and condemned, all research on stem cells deriving from the nuclear transfer of a somatic cell is prohibited, irrespective of the distinction between cloning for therapeutic purposes and reproductive cloning. It is undeniable that if the efficacy of somatic stem cells could be demonstrated, they would offer a far more preferable solution, for several reasons, than those involving stem cells obtained from spare embryos from IVF or nuclear transfer. Nevertheless, how will a comparison of the two methods be possible if one of them is prohibited a priori? At present, many fear that French researchers will be prevented from doing essential research that, even if it has far to go, is indispensable if we wish to attempt to control the failures of natural procreation and open the way towards the new regenerative medicine that so many look forward to.

Fetal hematopoietic stem cell transplantation: a challenge for the twenty-first century.

Successful in utero hematopoietic stem cell transplantation will likely represent a major step forward in the management of patients with congenital hematological, metabolic, and immunological disorders. We review the naturally occurring models of hematopoietic chimerism in animals and humans, as well as available experimental animal data and human clinical attempts of fetal transplantation. Data available from naturally occurring models and experimental models of fetal transplantation suggest that this technique should be translatable to the human fetus. However, to date, the success of human fetal hematopoietic stem cell therapy has been limited to fetuses with severe immunologic defects. Evaluation of successful attempts of human transplantation, the ontogeny of fetal immune development, and data available from animals provide insights into innovative approaches to fetal therapy that may bring the reality of successful fetal transplantation closer.

Medical provision in the twenty-first century.

193 On 21 November 2000, the United Kingdom’s House of Lords Select Committee on Science and Technology published a report on Complementary and Alternative Medicine (CAM) in Britain in response to a growing demand for these therapies. In light of significant advances in nuclear transfer experiments and its potential for treatment of trauma and a range of incurable and degenerative diseases (e.g., Parkinson’s disease, stroke, and spinal cord injuries), the House of Lords voted on 22 January 2001, to permit human embryonic stem cell research. Coincidentally, on 12 February 2001, the profile of the human genome was first published, presenting unique scientific opportunities that could alter the manner in which genetically complex human diseases are prevented or treated. Herein lies the paradox in medical provision. What impact could such scientific breakthroughs have on alternative medical practices, particularly herbal medicine, which has witnessed the biggest growth among alternative therapies with a current U.K. market estimated in the region of $340.8 million per annum (Kingston, 2001)? The appeal of herbal medicine and herbal supplements within the public health domain is well documented but is the concept of integrated medicine wholly unrealistic in the light of current scientific innovation and the enormous potential that it presents to medicine? The world is witnessing a technologic revolution and an explosion of scientific knowledge of amazing proportions. Advances in medical science have surpassed our wildest expectations, posing new therapeutic possibilities that constantly challenge and redefine the parameters of medical ethics. Nowhere is this more apparent than in the new developments in the biomedical sciences such as the Human Genome Project (HGP) and stem cell therapy. It may be difficult for herbalists to accept the applications of the latest medical breakthroughs readily, but it is essential that practitioners have knowledge of such developments for a number of reasons. For instance, an understanding of individual variation and disease susceptibility may benefit herbal therapeutic practice, particularly where the tailoring of herbal prescriptions to the individual patient is a crucial factor. This is made more pertinent when examining the effects of herbal remedies in different people, in addition to the concept of synergy of the active ingredients. To gain a full and accurate understanding of such scientific innovation could not only demonstrate the benefits of such techniques but could also clearly define the limitations and possibly any disadvantages that inadvertently favor herbal medicine. To be informed of treatment options that are available could improve understanding of patients’ perception of new scientific innovation, thus enabling a clear recognition of patients’ needs and appropriateness of treatment. Moreover, an increased awareness of the range of medical provision in the 21st century would give a clear indication of the context and framework in which herbal medicine is practiced. Although any future alliances between

Gene and stem cell therapies.

Gene and stem cell therapies hold promise for the treatment of a wide variety of inherited and acquired human diseases. Identification of genes involved in human disease and development of novel vectors and devices for delivering therapeutic genes to different tissues in vivo have resulted in significant progress in the area of gene therapy. Isolation of stem cells from organs formerly thought to have no regenerative potential, the demonstration of stem cell plasticity, and the creation of human embryonic stem cells clearly demonstrate the feasibility of human stem cell therapy. Much additional work remains to be done in the areas of vector development and stem cell biology before the full therapeutic potential of these approaches can be realized. Of equal importance, the ethical issues surrounding gene- and cell-based therapies must be confronted.