Efficient in vitro generation of adult multipotent cells from mobilized peripheral blood CD133+ cells

Effects of FGFR Tyrosine Kinase Inhibition in OLN-93 Oligodendrocytes

Fibroblast growth factor (FGF) signaling is involved in the pathogenesis of multiple sclerosis (MS). Data from neuropathology studies suggest that FGF signaling contributes to the failure of remyelination in MS. In MOG_35–55-induced EAE, oligodendrocyte-specific deletion of FGFR1 and FGFR2 resulted in a less severe disease course, reduced inflammation, myelin and axon degeneration and changed FGF/FGFR and BDNF/TrkB signaling. Since signaling cascades in oligodendrocytes could not be investigated in the EAE studies, we here aimed to characterize FGFR-dependent oligodendrocyte-specific signaling in vitro. FGFR inhibition was achieved by application of the multi-kinase-inhibitor dovitinib and the FGFR1/2/3-inhibitor AZD4547. Both substances are potent inhibitors of FGF signaling; they are effective in experimental tumor models and patients with malignancies. Effects of FGFR inhibition in oligodendrocytes were studied by immunofluorescence microscopy, protein and gene analyses. Application of the tyrosine kinase inhibitors reduced FGFR1, phosphorylated ERK and Akt expression, and it enhanced BDNF and TrkB expression. Furthermore, the myelin proteins CNPase and PLP were upregulated by FGFR inhibition. In summary, inhibition of FGFR signaling in oligodendrocytes can be achieved by application of tyrosine kinase inhibitors. Decreased phosphorylation of ERK and Akt is associated with an upregulation of BDNF/TrkB signaling, which may be responsible for the increased production of myelin proteins. Furthermore, these data suggest that application of FGFR inhibitors may have the potential to promote remyelination in the CNS.

Comparing stemness gene expression between stem cell subpopulations from peripheral blood and adipose tissue

Cell therapy presents a promising alternative for the treatment of degenerative diseases. The main sources of adult stem cells are bone marrow, adipose tissue and peripheral blood. Within those tissues, there are cell subpopulations that share pluripotential characteristics. Nevertheless, there is insufficient data to determine which of these stem cell subtypes would have a better possibility to differentiate to a specific tissue. The objective of this research was to analyze and compare the stemness genes expression from peripheral blood and adipose tissue of plastic adherent cells, and those immune-selected by the CD133⁺ and CD271⁺ membrane markers. On all cell subpopulation groups, self-renew capacity, the membranes markers CD73, CD90 and CD105, as well as the stemness genes NANOG, OCT4, SOX2, REX1, NOTCH1 and, NESTIN expression were analyzed. Results showed that all samples presented the minimal criteria to define them as human stem cells. All cell subpopulation were capable of self-renewal. Nevertheless, the subpopulation cell types showed differences on the time needed to reach confluence. The slowest doubling times were for those cells bearing the CD133 marker from both sources. Surface markers determined by flow cytometry were positive for CD73, CD90 and, CD105, and negative for CD45. The stemness gene expression was positive in all subpopulation. However, there were significant differences in the amount and pattern of expression among them. Those differences could be advantageous in finding the best option for their application on cell therapy. Cells with high expression of OCT4 gene could be a better opportunity for neuron differentiation like CD133⁺ blood cells. On the other hand, lowest expression of NOTCH1 on CD271⁺ cells from the same source could be a better possibility for myoblast differentiation. The observed differences could be used as an advantage to find which cell type and from the different source; this represents the best option for its application on cell therapy. Experiments focused on the best response to specific differentiation, are conducted in order to confirm those possibilities.

DPP4 Inhibitors Can Be a Drug of Choice for Type 3 Diabetes: A Mini Review

As well known to the scientific community, Alzheimer's disease (AD) is an irreversible neurodegenerative disease that ends up with impairment of memory and cognition due to neuronal and synapse loss. Patient's quality of life can be enhanced by targeting neurogenesis as a therapeutic paradigm. Moreover, several research evidences support the concept that AD is a type of metabolic disorder mediated by impairment in brain insulin responsiveness and energy metabolism. Growing evidence suggests that endogenous peptides such as glucagon-like peptide-1 (GLP-1) and stromal-derived factor-1α (SDF-1α) provide neuroprotection across a range of experimental models of AD. So, preserving functional activity of SDF-1α and GLP-1 by dipeptidyl peptidase-4 inhibition will enhance the homing/recruitment of brain resident and nonresident circulating stem cells/progenitor cells, a noninvasive approach for promoting neurogenesis. So, herewith we provide this in support of dipeptidyl peptidase-4 inhibitors as a new target of attention for treating AD.

Differentiation of CD133+ stem cells from amyotrophic lateral sclerosis patients into preneuron cells

Improvements in quality of life and life expectancy have been observed in amyotrophic lateral sclerosis (ALS) patients transplanted with CD133(+) stem cells into their frontal motor cortices. However, questions have emerged about the capacity of cells from these patients to engraft and differentiate into neurons. The objective of this work was to evaluate the in vitro capacity of CD133(+) stem cells from 13 ALS patients to differentiate into neuron lineage. Stem cells were obtained through leukapheresis and cultured in a control medium or a neuroinduction medium for 2-48 hours. Expression of neuronal genes was analyzed by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical techniques. Fluorescence microscopy demonstrated that CD133(+) stem cells from ALS patients incubated for 48 hours in a neuroinduction medium increased the detection of neuronal proteins such as nestin, β-tubulin III, neuronal-specific enolase, and glial fibrillary acidic protein. RT-PCR assays demonstrated an increase in the expression of β-tubulin III, nestin, Olig2, Islet-1, Hb9, and Nkx6.1. No correlation was found between age, sex, or ALS functional scale and the CD133(+) stem cell response to the neuroinduction medium. We conclude that CD133(+) stem cells from ALS patients, like the stem cells of healthy subjects, are capable of differentiating into preneuron cells.

Neurogenic and neuro-protective potential of a novel subpopulation of peripheral blood-derived CD133+ ABCG2+CXCR4+ mesenchymal stem cells: development of autologous cell-based therapeutics for traumatic brain injury

INTRODUCTION

Nervous system injuries comprise a diverse group of disorders that include traumatic brain injury (TBI). The potential of mesenchymal stem cells (MSCs) to differentiate into neural cell types has aroused hope for the possible development of autologous therapies for central nervous system injury.

METHODS

In this study we isolated and characterized a human peripheral blood derived (HPBD) MSC population which we examined for neural lineage potential and ability to migrate in vitro and in vivo. HPBD CD133+, ATP-binding cassette sub-family G member 2 (ABCG2)+, C-X-C chemokine receptor type 4 (CXCR4)+ MSCs were differentiated after priming with β-mercaptoethanol (β-ME) combined with trans-retinoic acid (RA) and culture in neural basal media containing basic fibroblast growth factor (FGF2) and epidermal growth factor (EGF) or co-culture with neuronal cell lines. Differentiation efficiencies in vitro were determined using flow cytometry or fluorescent microscopy of cytospins made of FACS sorted positive cells after staining for markers of immature or mature neuronal lineages. RA-primed CD133+ABCG2+CXCR4+ human MSCs were transplanted into the lateral ventricle of male Sprague-Dawley rats, 24 hours after sham or traumatic brain injury (TBI). All animals were evaluated for spatial memory performance using the Morris Water Maze (MWM) Test. Histological examination of sham or TBI brains was done to evaluate MSC survival, migration and differentiation into neural lineages. We also examined induction of apoptosis at the injury site and production of MSC neuroprotective factors.

RESULTS

CD133+ABCG2+CXCR4+ MSCs consistently expressed markers of neural lineage induction and were positive for nestin, microtubule associated protein-1β (MAP-1β), tyrosine hydroxylase (TH), neuron specific nuclear protein (NEUN) or type III beta-tubulin (Tuj1). Animals in the primed MSC treatment group exhibited MWM latency results similar to the uninjured (sham) group with both groups showing improvements in latency. Histological examination of brains of these animals showed that in uninjured animals the majority of MSCs were found in the lateral ventricle, the site of transplantation, while in TBI rats MSCs were consistently found in locations near the injury site. We found that levels of apoptosis were less in MSC treated rats and that MSCs could be shown to produce neurotropic factors as early as 2 days following transplantation of cells. In TBI rats, at 1 and 3 months post transplantation cells were generated which expressed markers of neural lineages including immature as well as mature neurons.

CONCLUSIONS

These results suggest that PBD CD133+ABCG2+CXCR4+ MSCs have the potential for development as an autologous treatment for TBI and neurodegenerative disorders and that MSC derived cell products produced immediately after transplantation may aid in reducing the immediate cognitive defects of TBI.

CD133-Positive Hematopoietic Stem Cells: From Biology to Medicine

Lifelong hematopoiesis is sustained by a very small number of hematopoietic stem cells capable of self-renewal and differentiation into multiple hematopoietic lineages. The sialomucin CD34 has been, and is currently, used for the identification and purification of primitive hematopoietic progenitors. Depending on the source of stem cells, CD34 may not be expressed on all progenitor cells. An alternative stem cell marker is prominin-1 (CD133), which is expressed on a subpopulation of CD34(+) cells as well as on CD34(-) progenitor cells derived from various sources including fetal liver and bone marrow, adult bone marrow, cord blood, and mobilized peripheral blood. CD133(+) stem cells can reconstitute myelo- and lymphopoiesis of lethally irradiated mice, and the characterization of the CD133 expression on stem cells provides some insights into the biology of the hierarchy and functional organization of human hematopoiesis. The availability of methods for clinical large-scale isolation of CD133(+) cells facilitates their use in autologous and allogeneic hematopoietic stem cell transplantation and possibly in other fields of regenerative medicine.

MRI tracking of FePro labeled fresh and cryopreserved long term in vitro expanded human cord blood AC133+ endothelial progenitor cells in rat glioma

BACKGROUND

Endothelial progenitors cells (EPCs) are important for the development of cell therapies for various diseases. However, the major obstacles in developing such therapies are low quantities of EPCs that can be generated from the patient and the lack of adequate non-invasive imaging approach for in vivo monitoring of transplanted cells. The objective of this project was to determine the ability of cord blood (CB) AC133+ EPCs to differentiate, in vitro and in vivo, toward mature endothelial cells (ECs) after long term in vitro expansion and cryopreservation and to use magnetic resonance imaging (MRI) to assess the in vivo migratory potential of ex vivo expanded and cryopreserved CB AC133+ EPCs in an orthotopic glioma rat model.

MATERIALS, METHODS AND RESULTS

The primary CB AC133+ EPC culture contained mainly EPCs and long term in vitro conditions facilitated the maintenance of these cells in a state of commitment toward endothelial lineage. At days 15-20 and 25-30 of the primary culture, the cells were labeled with FePro and cryopreserved for a few weeks. Cryopreserved cells were thawed and in vitro differentiated or i.v. administered to glioma bearing rats. Different groups of rats also received long-term cultured, magnetically labeled fresh EPCs and both groups of animals underwent MRI 7 days after i.v. administration of EPCs. Fluorescent microscopy showed that in vitro differentiation of EPCs was not affected by FePro labeling and cryopreservation. MRI analysis demonstrated that in vivo accumulation of previously cryopreserved transplanted cells resulted in significantly higher R2 and R2* values indicating a higher rate of migration and incorporation into tumor neovascularization of previously cryopreserved CB AC133+ EPCs to glioma sites, compared to non-cryopreserved cells.

CONCLUSION

Magnetically labeled CB EPCs can be in vitro expanded and cryopreserved for future use as MRI probes for monitoring the migration and incorporation to the sites of neovascularization.

Immune maintenance of self in morphostasis of distinct tissues, tumour growth and regenerative medicine

Morphostasis (tissue homeostasis) is a complex process consisting of three circumstances: (1) tissue renewal from stem cells, (2) preservation of tissue cells in a proper differentiated state and (3) maintenance of tissue quantity. This can be executed by a tissue control system (TCS) consisting of vascular pericytes, immune system-related components--monocyte-derived cells (MDC), T cells and immunoglobulins and autonomic innervation. Morphostasis is established epigenetically, during the critical developmental period corresponding to the morphogenetic immune adaptation. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a 'stop effect' of MDC influencing markers of differentiating tissue cells and presenting self-antigens to T cells. Retardation or acceleration of certain tissue differentiation during adaptation results in its persistent functional immaturity or premature ageing. The tissues being absent during adaptation, like ovarian corpus luteum, are handled as a 'graft.' Morphostasis is altered with age advancement, because of the degenerative changes of the immune system. That is why the ageing of individuals and increased incidence of neoplasia and degenerative diseases occur. Hybridization of tumour stem cells with normal tissue cells causes an augmentation of neoplasia by host pericytes and MDC stimulating a 'regeneration' of depleted functional cells. Degenerative diseases are associated with apoptosis. If we are able to change morphostasis in particular tissue, we may disrupt apoptotic process of the cell. An ability to manage the 'stop effect' of MDC may provide treatment for early post-natal tissue disorders, improve regenerative medicine and delay physical, mental and hormonal ageing.

Glial cell lines: an overview

The importance and essential functions of glial cells in the nervous system are now beginning to be understood and appreciated. Glial cell lines have been instrumental in the elucidation of many of these properties. In this Overview, the origin and properties of most of the existing cell lines for the major glial types: oligodendroglia, astroglia, microglia and Schwann cells, are documented. Particular emphasis is given to the culture conditions for each cell line and the degree to which the line can differentiate in vitro and in vivo. The major molecular markers for each glial cell lines are indicated. Finally, methods by which the glial cell lines have been developed are noted and the future directions of glial cell line research are discussed.

Human Bone Marrow-Derived CD133+ Cells Delivered to a Collagen Patch on Cryoinjured Rat Heart Promote Angiogenesis and Arteriogenesis

Transplanting hematopoietic and peripheral blood-derived stem/progenitor cells can have beneficial effects in slowing the effects of heart failure. We investigated whether human bone marrow CD133+-derived cells (BM-CD133+ cells) might be used for cell therapy of heart injury in combination with tissue engineering. We examined these cells for: 1) their in vitro capacity to be converted into cardiomyocytes (CMs), and 2) their potential for in vivo differentiation when delivered to a tissue-engineered type I collagen patch placed on injured hearts (group II). To ensure a microvascular network ready for use by the transplanted cells, cardiac injury and patching were scheduled 2 weeks before cell injection. The cardiovascular potential of the BM-CD133+ cells was compared with that of a direct injection (group I) of the same cells in heart tissue damaged according to the same schedule as for group II. While a small fraction (2 ± 0.5%) of BM-CD133+cells cocultured with rat CMs switched in vitro to a CM-like cell phenotype, in vivo—and in both groups of nude rats transplanted with BM-CD133+—there was no evidence of any CM differentiation (as detected by cardiac troponin I expression), but there were signs instead of new capillaries and small arterioles. While capillaries prevailed over arterioles in group II, the opposite occurred in group I. The transplanted cells further contributed to the formation of new microvessels induced by the patch (group II) but the number of vessels did not appear superior to the one developed after directly injecting the BM-CD133+cells into the injured heart. Although chimeric human–rat microvessels were consistently found in the hearts of both groups I and II, they represented a minority (1.5–2.3%) compared with those of rat origin. Smooth muscle myosin isoform expression suggested that the arterioles achieved complete differentiation irrespective of the presence or absence of the collagen patch. These findings suggest that: 1) BM-CD133+ cells display a limited propensity for in vitro conversion to CMs; 2) the preliminarily vascularized bioscaffold did not confer a selective homing and differentiation advantage for the phenotypic conversion of BM-CD133+ cells into CMs; and 3) combined patching and cell transplantation is suitable for angiogenesis and arteriogenesis, but it does not produce better results, in terms of endothelial and smooth muscle cell differentiation, than the “traditional” method of cell injection into the myocardium.

Proliferation and differentiation potential of CD133+ and CD34+ populations from the bone marrow and mobilized peripheral blood

CD34 is the most frequently used marker for the selection of cells for bone marrow (BM) transplantation. The use of CD133 as an alternative marker is an open research topic. The goal of this study was to evaluate the proliferation and differentiation potential for hematopoiesis (short and long term) of CD133+ and CD34+ populations from bone marrow and mobilized peripheral blood. Eight cell populations were compared: CD34+ and CD133+ cells from both the BM (CML Ph-, CML Ph+, and healthy volunteers) and mobilized peripheral blood cells. Multicolor flow cytometry and cultivation experiments were used to measure expression and differentiation of the individual populations. It was observed that the CD133+ BM population showed higher cell expansion. Another finding is that during a 6-day cultivation with 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (CFSE), more cells remained in division D0 (non-dividing cells). There was a higher percentage of CD38- cells observed on the CD133+ BM population. It was also observed that the studied populations contained very similar but not the same pools of progenitors: erythroid, lymphoid, and myeloid. This was confirmed by CFU-GM and CFU-E experiments. The VEGFR antigen was used to monitor subpopulations of endothelial sinusoidal progenitors. The CD133+ BM population contained significantly more VEGFR+ cells. Our findings suggest that the CD133+ population from the BM shows better proliferation activity and a higher distribution of primitive progenitors than any other studied population.

Human cord blood-derived AC133+ progenitor cells preserve endothelial progenitor characteristics after long term in vitro expansion

Background

Stem cells/progenitors are central to the development of cell therapy approaches for vascular ischemic diseases. The crucial step in rescuing tissues from ischemia is improvement of vascularization that can be achieved by promoting neovascularization. Endothelial progenitor cells (EPCs) are the best candidates for developing such an approach due to their ability to self-renew, circulate and differentiate into mature endothelial cells (ECs). Studies showed that intravenously administered progenitors isolated from bone marrow, peripheral or cord blood home to ischemic sites. However, the successful clinical application of such transplantation therapy is limited by low quantities of EPCs that can be generated from patients. Hence, the ability to amplify the numbers of autologous EPCs by long term in vitro expansion while preserving their angiogenic potential is critically important for developing EPC based therapies. Therefore, the objective of this study was to evaluate the capacity of cord blood (CB)-derived AC133+ cells to differentiate, in vitro, towards functional, mature endothelial cells (ECs) after long term in vitro expansion.

Methodology

We systematically characterized the properties of CB AC133+ cells over the 30 days of in vitro expansion. During 30 days of culturing, CB AC133+ cells exhibited significant growth potential that was manifested as 148-fold increase in cell numbers. Flow cytometry and immunocytochemistry demonstrated that CB AC133+ cells' expression of endothelial progenitor markers was not affected by long term in vitro culturing. After culturing under EC differentiation conditions, cells exhibited high expression of mature ECs markers, such as CD31, VEGFR-2 and von Willebrand factor, as well as the morphological changes indicative of differentiation towards mature ECs. In addition, throughout the 30 day culture cells preserved their functional capacity that was demonstrated by high uptake of DiI fluorescently conjugated-acetylated-low density lipoprotein (DiI-Ac-LDL), in vitro and in vivo migration towards chemotactic stimuli and in vitro tube formation.

Conclusions

These studies demonstrate that primary CB AC133+ culture contained mainly EPCs and that long term in vitro conditions facilitated the maintenance of these cells in the state of commitment towards endothelial lineage.

Basic research and clinical applications of non-hematopoietic stem cells, 4-5 April 2008, Tubingen, Germany

From 4 to 5 April 2008, international experts met for the second time in Tubingen, Germany, to present and discuss the latest proceedings in research on non-hematopoietic stem cells (NHSC). This report presents issues of basic research including characterization, isolation, good manufacturing practice (GMP)-like production and imaging as well as clinical applications focusing on the regenerative and immunomodulatory capacities of NHSC.

Immune physiology in tissue regeneration and aging, tumor growth, and regenerative medicine

The immune system plays an important role in immunity (immune surveillance), but also in the regulation of tissue homeostasis (immune physiology). Lessons from the female reproductive tract indicate that immune system related cells, such as intraepithelial T cells and monocyte-derived cells (MDC) in stratified epithelium, interact amongst themselves and degenerate whereas epithelial cells proliferate and differentiate. In adult ovaries, MDC and T cells are present during oocyte renewal from ovarian stem cells. Activated MDC are also associated with follicular development and atresia, and corpus luteum differentiation. Corpus luteum demise resembles rejection of a graft since it is attended by a massive influx of MDC and T cells resulting in parenchymal and vascular regression. Vascular pericytes play important roles in immune physiology, and their activities (including secretion of the Thy-1 differentiation protein) can be regulated by vascular autonomic innervation. In tumors, MDC regulate proliferation of neoplastic cells and angiogenesis. Tumor infiltrating T cells die among malignant cells. Alterations of immune physiology can result in pathology, such as autoimmune, metabolic, and degenerative diseases, but also in infertility and intrauterine growth retardation, fetal morbidity and mortality. Animal experiments indicate that modification of tissue differentiation (retardation or acceleration) during immune adaptation can cause malfunction (persistent immaturity or premature aging) of such tissue during adulthood. Thus successful stem cell therapy will depend on immune physiology in targeted tissues. From this point of view, regenerative medicine is more likely to be successful in acute rather than chronic tissue disorders.