Source Of Stem Cells For Transplantation Research Articles

Atoh1 overexpression promotes Guinea pig bone marrow mesenchymal stem cells to differentiate into neural stem cell

Sensorineural hearing loss (SNHL) is a prevalent condition in otolaryngology. A key obstacle is finding effective strategies for regenerating damaged cochlear hair cells in adult animals. A practical and reliable approach has been developed to create a superior cell source for stem cell transplantation in the inner ear to treat SNHL. Atoh1 is involved in the differentiation of neurons, intestinal secretory cells, and mechanoreceptors including auditory hair cells, and thus plays an important role in neurogenesis. Lentivirus-mediated transfection of bone marrow mesenchymal stem cells (BMSCs) was utilized to achieve stable expression of the essential transcription factor Atoh1, which is crucial for developing auditory hair cells without compromising cell survival. By manipulating the induction conditions through altering the cell growth environment using anti-adherent culture, the synergistic impact of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) was effectively applied to significantly improve the differentiation efficiency of bone marrow-derived mesenchymal stem cells (BMSC) into neural stem cells (NSCs) following Atoh1 transfection, thereby reducing the induction time. The study indicated that the newly proposed transdifferentiation method effectively transformed BMSCs into NSCs in a controlled environment, presenting a potential approach for stem cell transplantation to promote hair cell regeneration.

Hypoxia improves self-renew and migration of urine-derived stem cells by upregulating autophagy and mitochondrial function through ERK signal pathway

Urine-derived stem cells (USCs) are autologous stem cells with self-renewal ability and multi-lineage differentiation potential. Our previous studies have shown that hypoxia preconditioning can improve self-renewal and migration abilities of USCs by up-regulating autophagy. The purpose of this study was to investigate the specific mechanism by which hypoxia treatment promotes the biological function of USCs. We found that hypoxia treatment upregulated the expression of phosphralated ERK protein without affecting the expression of total ERK protein. Inhibiting ERK signaling with the PD98059 inhibitor decreased cell proliferation, migration and colony formation during hypoxia treatment. Hypoxia increased ATP production, mitochondrial membrane potential and mt-DNA copy number, which were reversed by inhibiting the ERK signal. Additionally, the number of autophagosomes and autophagic lysosomes was significantly lower in PD98059 group than in the hypoxia group. PD98059 treatment inhibited the up-regulation of autophagy related proteins induced by hypoxia. Therefore, this study suggests that hypoxia improves the self-renewal and migration abilities of USCs by upregulating autophagy and mitochondrial function through ERK signaling pathway. This finding may provide a new therapeutic mechanism for hypoxia pretreated USCs as a source of stem cell transplantation.

Assessment of HLA-B genetic variation with an HLA-B leader tool and implications in clinical transplantation

AbstractSequence variation in the HLA-B gene is critically linked to differential immune responses. A dimorphism at -21 of HLA-B exon 1 gives rise to leader peptides that are markers for risk of acute graft-versus-host disease, relapse, and mortality after unrelated donor and cord blood transplantation. To optimize the selection of stem cell transplant sources based on the HLA-B leader, an HLA-BLeader Assessment Tool (BLEAT) was developed to automate the assignment of leader genotypes, define HLA-B leader match statuses, and rank order candidate stem cell sources according to clinical risk. The base cohort consisted of 9 417 614 registered donors from the Be The Match Registry with HLA-B typing. Among these donors, the performance of BLEAT was assessed in 1 098 358 donors with sequence data for HLA-B exon 1 (2 196 716 haplotypes). The accuracy of leader assignment was then assessed in a second cohort of 1259 patients and their unrelated transplant donors. We furthermore established the frequencies of HLA-B leader genotype (MM, MT, TT) representations in broad racial categories in the 9.42 million donors. BLEAT has direct applications for the selection of optimal stem cell sources for transplantation and broad utility in basic and clinical research in pharmacogenomics, vaccine development, and cancer and infectious disease studies of human populations.

Cell transplantation to replace retinal ganglion cells faces challenges - the Switchboard Dilemma.

The mammalian retina displays incomplete intrinsic regenerative capacities; therefore, retina degeneration is a major cause of irreversible blindness such as glaucoma, age-related macular degeneration and diabetic retinopathy. These diseases lead to the loss of retinal cells and serious vision loss in the late stage. Stem cell transplantation is a great promising novel treatment for these incurable retinal degenerative diseases and represents an exciting area of regenerative neurotherapy. Several suitable stem cell sources for transplantation including human embryonic stem cells, induced pluripotent stem cells and adult stem cells have been identified as promising target populations. However, the retina is an elegant neuronal complex composed of various types of cells with different functions. The replacement of these different types of cells by transplantation should be addressed separately. So far, retinal pigment epithelium transplantation has achieved the most advanced stage of clinical trials, while transplantation of retinal neurons such as retinal ganglion cells and photoreceptors has been mostly studied in pre-clinical animal models. In this review, we opine on the key problems that need to be addressed before stem cells transplantation, especially for replacing injured retinal ganglion cells, may be used practically for treatment. A key problem we have called the Switchboard Dilemma is a major block to have functional retinal ganglion cell replacement. We use the public switchboard telephone network as an example to illustrate different difficulties for replacing damaged components in the retina that allow for visual signaling. Retinal ganglion cell transplantation is confronted by significant hurdles, because retinal ganglion cells receive signals from different interneurons, integrate and send signals to the correct targets of the visual system, which functions similar to the switchboard in a telephone network – therefore the Switchboard Dilemma.

Prognostic Value of Refined Disease Risk Index (rDRI) and Conditioning Regimen in Adult Patients Receiving Unrelated Cord Blood Transplantation (UCBT) for Haematological Malignancies - 15-Year Follow-up of Multicenter Study in Singapore

Introduction: Umbilical cord blood (UCB) is an established stem cell source for transplantation in patients with hematological diseases who lack suitable related or unrelated donors. Refined Disease Risk Index (rDRI) is a prognostic tool used in hematopoietic cell transplant (HCT), solely based on disease type and status. Its value in patients undergoing UCB transplants (UCBT) with different conditioning regime intensity is unclear. We sought to evaluate the predictive value of rDRI in patients undergoing UCBT. Methods: We performed a retrospective analysis of 107 adult patients with various hematological malignancies who underwent 4-6/6 HLA-matched UCBT using single unit UCB (n=14) or double unit UCB (n=93) between Aug 2006 and Nov 2019 at 2 academic tertiary hospitals in Singapore. Patients received pre-transplant conditioning with either myeloablative conditioning (MAC, n=63) regimen consisting of Fludarabine (Flu) 75mg/m2, Cyclophosphamide (Cy) 120mg/kg and total body irradiation (TBI) 12- 13.2Gy , intensified reduced intensity conditioning (i-RIC, N=22) regimen consisting of Flu 150 mg/m2, Cy 50mg/kg, thiotepa 10mg/kg and TBI 4 Gy, or nonmyeloablative conditioning (NM, n=22) regimen, consisting of Flu 200 mg/m2, Cy 50mg/kg and TBI 2 Gy. The median total nucleated cell dose infused was 5.07 x 107/kg (range, 2.61 to 11.5) Results: Median follow-up was 84 months (range, 6 to 167 months).. Kaplan-Meier estimates of overall (OS) and event-free (EFS) survival at 10 years were 40 % (95% CI, 31-50) and 37% (95% CI, 28-47) respectively. At 2 years, cumulative incidence (CI) of relapse-related mortality (RRM) and non-relapse mortality (NRM) were 27% (95% CI, 18-35) and 35 % (95% CI, 25-45), respectively. In multivariate analysis (MVA), rDRI showed significant correlation with OS (HR 2.41; 95% CI 1.41-4.11; p=0.001), EFS (HR 2.54; 95% CI 1.51-4.28; p=0.0004) and RRM (HR 2.71; 95% 1.36-5.41; p=0.005). Conditioning regimen intensity was found to have significant impact on NRM (p=0.047) and RRM (p=0.002) in MVA. When patients were further stratified into 4 risk groups incorporating both rDRI and conditioning regimen intensity, significant differences in OS (p=0.002) and EFS (p=0.001) were seen. 5-year OS (Figure 1) in patients receiving MAC/i-RIC and NM conditioning with low-intermediate risk rDRI were 52% and 36% respectively, compared with 24% and 13% in patients with high-very high risk rDRI (p=0.002). The corresponding ES were 50%, 29%, 20%, and 13%, respectively (Figure2). Conclusions: Our results confirm that rDRI has good predictive value for relapse and survival in UCBT recipients. Conditioning regime intensity was also found to have a significant impact on patient outcomes when evaluated together with rDRI. Prognostic scoring systems in HSCT are revised constantly with further studies needed to potentially incorporate the intensity of the conditioning regime into the rDRI. Outcomes in rDRI high risk patients remain poor and further studies are needed to define the best strategy that can induce sustained engraftment without increasing risk of relapse and toxicity death. Disclosures No relevant conflicts of interest to declare.

IGF-1R stimulation alters microglial polarization via TLR4/NF-κB pathway after cerebral hemorrhage in mice

Intracerebral hemorrhage (ICH) is a common neurological disease, causing severe disability and even deaths. Stem cell transplantation has been increasingly used in stroke therapy, and neural stem cells (NSCs) are a good source for stem cell transplantation. However, the regulatory mechanism of NSCs remains unclear. In this study, we examined the impact of insulin-like growth factor-1 (IGF-1) secreted by NSCs on microglial polarization following ICH in adult C57BL/6 mice. Mouse models of ICH were established by collagenase injection. ICH mice received NSC transplantation 1 h after model establishment. Firstly, the changes of microglial polarization in cerebral tissues of ICH mice were detected by immunofluorescence and ELISA. Secondly, the molecular mechanism underlying the microglial polarization was evaluated repeatedly with the application of IGF-1R siRNA and IGF-1R-mediated inhibition. We assessed the brain water content and behavioral deficits of ICH mice 12, 24, 48, and 72 h after surgery. The survival of neurons in the brain was examined using Nissl staining and TUNEL staining at 72 h. The TLR4/NF-κB pathway implicated in ICH-induced inflammation was profiled by Western blot analysis and immunohistochemistry. Finally, the changes in microglia after ICH in mice were re-examined under different doses of rhIGF-1. In summary, NSC transplantation changed microglial polarization in ICH mice. IGF-1R inhibition and knockdown reversed the therapeutic effect of NSCs, and rhIGF-1 had an anti-inflammatory effect. The results of this study suggest that IGF-1R stimulation is a potential target for stem cell-based treatment of cerebral hemorrhage and may attenuate inflammatory response in the brain after bleeding.

Aligned collagen scaffold combination with human spinal cord-derived neural stem cells to improve spinal cord injury repair.

Neural stem/progenitor cell (NSPC)-based spinal cord injury (SCI) therapy is expected to bridge the lesion site by transplanting exogenous NSPCs for replacement of lost cells. The transplanted NSPCs produce a microenvironment conducive to neuronal regeneration, and ultimately, functional recovery. Although both human fetal brain- and spinal cord- derived NSPCs (hbNSPCs and hscNSPCs, respectively) have been used for SCI repair, it remains unclear whether hscNSPCs are a more appropriate stem cell source for transplantation than hbNSPCs. Therefore, in this study, we transplanted hbNSPCs or hscNSPCs into rats with complete transection SCI to monitor their differences in SCI treatment. An aligned collagen sponge scaffold (ACSS) was used here for cell retention. Aligned biomaterial scaffolds provide a support platform and favorable morphology for cell growth and differentiation, and guide axial axonal extension. The ACSS fabricated by our group has been previously reported to improve spinal cord repair by promoting neuronal regeneration and remyelination. Compared with the hbNSPC-ACSS, the hscNSPC-ACSS effectively promoted long-term cell survival and neuronal differentiation and improved the SCI microenvironment by reducing inflammation and glial scar formation. Furthermore, the transplanted hscNSPC-ACSS improved recovery of locomotor functions. Therefore, hscNSPCs appear to be a superior cell source to hbNSPCs for SCI cell therapy with greater potential clinical applications.

Controlling properties of human neural progenitor cells using 2D and 3D conductive polymer scaffolds

Human induced pluripotent stem cell-derived neural progenitor cells (hNPCs) are a promising cell source for stem cell transplantation to treat neurological diseases such as stroke and peripheral nerve injuries. However, there have been limited studies investigating how the dimensionality of the physical and electrical microenvironment affects hNPC function. In this study, we report the fabrication of two- and three-dimensional (2D and 3D respectively) constructs composed of a conductive polymer to compare the effect of electrical stimulation of hydrogel-immobilized hNPCs. The physical dimension (2D vs 3D) of stimulating platforms alone changed the hNPCs gene expression related to cell proliferation and metabolic pathways. The addition of electrical stimulation was critical in upregulating gene expression of neurotrophic factors that are important in regulating cell survival, synaptic remodeling, and nerve regeneration. This study demonstrates that the applied electrical field controls hNPC properties depending on the physical nature of stimulating platforms and cellular metabolic states. The ability to control hNPC functions can be beneficial in understanding mechanistic changes related to electrical modulation and devising novel treatment methods for neurological diseases.

Immunophenotypic, cytotoxic, proteomic and genomic characterization of human cord blood vs. peripheral blood CD56Dim NK cells.

Unrelated cord blood (CB) is an excellent alternative as an allogeneic donor source for stem cell transplantation. CB transplantation is associated with lower incidence of severe acute graft versus host disease (GVHD) and chronic GVHD but similar rates of malignant relapse compared with other unrelated donor cell transplants. NK cells are critical innate immune components and the comparison of CB vs. peripheral blood (PB) NK cells is relatively unknown. NK cell receptor expression, cell function, and maturation may play a role in the risk of relapse after CB transplant. We investigated CB vs. PB NK cell subset cytotoxicity, function, receptor expression, and genomic and proteomic signatures. The CB CD56dim compared with PB CD56dim demonstrated significantly increased expression of NKG2A and NKG2D, respectively. CB vs. PB CD56dim NK cells had significantly decreased in vitro cytotoxicity against a variety of non-Hodgkin lymphoma targets. Various proteins were significantly under- and over-expressed in CB vs. PB CD56dim NK cells. Microarray analyses and qRT-PCR in CB vs. PB CD56dim demonstrated significantly increased expression of genes in cell regulation and development of apoptosis, respectively. In summary, CB vs. PB CD56dim NK cells appear to be earlier in development, have decreased functional activity, and increased capacity for programmed cell death, suggesting that CB NK cells require functional and maturational stimulation to achieve similar functional levels as PB CD56dim NK cells.

Stem cell transplantation for Huntington's diseases.

Therapeutic approaches based on stem cells have received considerable attention as potential treatments for Huntington's disease (HD), which is a fatal, inherited neurodegenerative disorder, caused by progressive loss of GABAergic medium spiny neurons (MSNs) in the striatum of the forebrain. Transplantation of stem cells or their derivatives in animal models of HD, efficiently improved functions by replacing the damaged or lost neurons. In particular, neural stem cells (NSCs) for HD treatments have been developed from various sources, such as the brain itself, the pluripotent stem cells (PSCs), and the somatic cells of the HD patients. However, the brain-derived NSCs are difficult to obtain, and the PSCs have to be differentiated into a population of the desired neuronal cells that may cause a risk of tumor formation after transplantation. In contrast, induced NSCs, derived from somatic cells as a new stem cell source for transplantation, are less likely to form tumors. Given that the stem cell transplantation strategy for treatment of HD, as a genetic disease, is to replace the dysfunctional or lost neurons, the correction of mutant genes containing the expanded CAG repeats is essential. In this review, we will describe the methods for obtaining the optimal NSCs for transplantation-based HD treatment and the differentiation conditions for the functional GABAergic MSNs as therapeutic cells. Also, we will discuss the valuable gene correction of the disease stem cells by the CRISPR/Cas9 system for HD treatment.

Harnessing CXCR4 antagonists in stem cell mobilization, HIV infection, ischemic diseases, and oncology.

CXCR4 antagonists (e.g., PlerixaforTM ) have been successfully validated as stem cell mobilizers for peripheral blood stem cell transplantation. Applications of the CXCR4 antagonists have heralded the era of cell-based therapy and opened a potential therapeutic horizon for many unmet medical needs such as kidney injury, ischemic stroke, cancer, and myocardial infarction. In this review, we first introduce the central role of CXCR4 in diverse cellular signaling pathways and discuss its involvement in several disease progressions. We then highlight the molecular design and optimization strategies for targeting CXCR4 from a large number of case studies, concluding that polyamines are the preferred CXCR4-binding ligands compared to other structural options, presumably by mimicking the highly positively charged natural ligand CXCL12. These results could be further justified with computer-aided docking into the CXCR4 crystal structure wherein both major and minor subpockets of the binding cavity are considered functionally important. Finally, from the clinical point of view, CXCR4 antagonists could mobilize hematopoietic stem/progenitor cells with long-term repopulating capacity to the peripheral blood, promising to replace surgically obtained bone marrow cells as a preferred source for stem cell transplantation.

A Hyper-Crosslinked Carbohydrate Polymer Scaffold Facilitates Lineage Commitment and Maintains a Reserve Pool of Proliferating Cardiovascular Progenitors.

BackgroundCardiovascular progenitor cells (CPCs) have been cultured on various scaffolds to resolve the challenge of cell retention after transplantation and to improve functional outcome after cell-based cardiac therapy. Previous studies have reported successful culture of fully differentiated cardiomyocytes on scaffolds of various types, and ongoing efforts are focused on optimizing the mix of cardiomyocytes and endothelial cells as well as on the identification of a source of progenitors capable of reversing cardiovascular damage. A scaffold culture that fosters cell differentiation into cardiomyocytes and endothelial cells while maintaining a progenitor reserve would benefit allogeneic cell transplantation.MethodsIsl-1 + c-Kit + CPCs were isolated as clonal populations from human and sheep heart tissue. After hyper-crosslinked carbohydrate polymer scaffold culture, cells were assessed for differentiation, intracellular signaling, cell cycling, and growth factor/chemokine expression using real time polymerase chain reaction, flow cytometry, immunohistochemistry, and calcium staining.ResultsInsulin-like growth factor 1, hepatocyte growth factor, and stromal cell derived factor 1α paracrine factors were induced, protein kinase B signaling was activated, extracellular signal-regulated kinase phosphorylation was reduced and differentiation into both cardiomyocytes and endothelial cells was induced by scaffold-based cell culture. Interestingly, movement of CPCs out of the G1 phase of the cell cycle and increased expression of pluripotency genes PLOU5F1 (Oct4) and T (Brachyury) within a portion of the cultured population occurred, which suggests the maintenance of a progenitor population. Two-color immunostaining and 3-color fluorescence-activated cell sorting analysis confirmed the presence of both Isl-1 expressing undifferentiated cells and differentiated cells identified by troponin T and von Willebrand factor expression. Ki-67 labeling verified the presence of proliferating cells that remained in situ alongside the differentiated functional derivatives.ConclusionsCloned Isl-1 + c-kit + CPCs maintained on a hyper-cross linked polymer scaffold retain dual potential for proliferation and differentiation, providing a scaffold-based stem cell source for transplantation of committed and proliferating cardiovascular progenitors for functional testing in preclinical models of cell-based repair.

The effect of maternal and infant factors on cord blood yield.

Umbilical cord blood (CB) can be used as an alternative hematopoietic stem cell source for transplantation in hematological malignancy and blood disorders. The success of transplantation is highly related to the levels of total nucleated cell and CD34+ cell counts. The evaluation of optimal conditions can decrease the rate of graft rejection due to low cell count and increases the quality of CB units (CBUs) in the blood bank and the success rate of engraftment. To this end, we review the maternal and infant parameters affecting the quality and quantity of CBUs.

HapLogic: A Predictive Human Leukocyte Antigen–Matching Algorithm to Enhance Rapid Identification of the Optimal Unrelated Hematopoietic Stem Cell Sources for Transplantation

The search for a suitable human leukocyte antigen (HLA)–matched unrelated adult stem cell donor (URD) or umbilical cord blood unit (UCB) is a complex process. The National Marrow Donor Program (NMDP) developed a search algorithm known as HapLogic, which is currently provided within the NMDP Traxis application. The HapLogic algorithm has been in use since 2006 and has advanced URD/UCB HLA-matching technology. The algorithm has been shown to have high predictive accuracy, which can streamline URD/UCB selection and drive efficiencies in the search process to the benefit of the stem cell transplantation community. Here, we describe the fundamental components of the NMDP matching algorithm, output, validation, and future directions.

Transplantation of Unique Subpopulation of Fibroblasts, Muse Cells, Ameliorates Experimental Stroke Possibly via Robust Neuronal Differentiation.

Muse cells reside as pre-existing pluripotent-like stem cells within the fibroblasts, are nontumorigenic, exhibit differentiation capacity into triploblastic-lineage cells, and replenish lost cells when transplanted in injury models. Cell fate and function of human skin fibroblast-derived Muse cells were evaluated in a rat stroke model. Muse cells (30,000), collected by pluripotent surface marker stage-specific embryonic antigen-3, were injected stereotaxically into three deposits within the rat ischemic cortex at 2 days after transient middle cerebral artery occlusion, and the cells' biological effects were examined for more than 84 days. Muse cells spontaneously and promptly committed to neural/neuronal-lineage cells when cocultured with stroke brain slices. Muse-transplanted stroke rats exhibited significant improvements in neurological and motor functions compared to control groups at chronic days 70 and 84, without a reduction in the infarct size. Muse cells survived in the host brain for up to 84 days and differentiated into NeuN (∼ 65%), MAP-2 (∼ 32%), calbindin (∼ 28%), and GST-π (∼ 25%)-positive cells in the cortex, but glial fibrillary acidic protein-positive cells were rare. Tumor formation was not observed. Muse cells integrated into the sensory-motor cortex, extended their neurites into cervical spinal cord, and displayed normalized hind limb somatosensory evoked potentials. Muse cells are unique from other stem cells in that they differentiate with high ratio into neuronal cells after integration with host brain microenvironment, possibly reconstructing the neuronal circuit to mitigate stroke symptoms. Human fibroblast-derived Muse cells pose as a novel source of transplantable stem cells, circumventing the need for gene manipulations, especially when contemplating autologous cell therapy for stroke.

In vitro chondrogenic commitment of human Wharton's jelly stem cells by co-culture with human articular chondrocytes

Wharton's jelly stem cells (WJSCs) are a potential source of transplantable stem cells in cartilage-regenerative strategies, due to their highly proliferative and multilineage differentiation capacity. We hypothesized that a non-direct co-culture system with human articular chondrocytes (hACs) could enhance the potential chondrogenic phenotype of hWJSCs during the expansion phase compared to those expanded in monoculture conditions. Primary hWJSCs were cultured in the bottom of a multiwell plate separated by a porous transwell membrane insert seeded with hACs. No statistically significant differences in hWJSCs duplication number were observed under either of the culture conditions during the expansion phase. hWJSCs under co-culture conditions show upregulations of collagen type I and II, COMP, TGFβ1 and aggrecan, as well as of the main cartilage transcription factor, SOX9, when compared to those cultured in the absence of chondrocytes. Chondrogenic differentiation of hWJSCs, previously expanded in co-culture and monoculture conditions, was evaluated for each cellular passage using the micromass culture model. Cells expanded in co-culture showed higher accumulation of glycosaminoglycans (GAGs) compared to cells in monoculture, and immunohistochemistry for localization of collagen type I revealed a strong detection signal when hWJSCs were expanded under monoculture conditions. In contrast, type II collagen was detected when cells were expanded under co-culture conditions, where numerous round-shaped cell clusters were observed. Using a micromass differentiation model, hWJSCs, previously exposed to soluble factors secreted by hACs, were able to express higher levels of chondrogenic genes with deposition of cartilage extracellular matrix components, suggesting their use as an alternative cell source for treating degenerated cartilage. Copyright © 2015 John Wiley & Sons, Ltd.

Here comes the cord.

Hematopoietic stem cell transplantation has been established as a lifesaving therapy for leukemias or other hematopoietic malignancies since more than a half century ago [1]. Human leukocyte antigen (HLA)-matched sibling is the preferred donor for the better clinical outcomes, whiles, even patients without suitable family donor could also receive the benefits from unrelated donor registries or cord blood (CB) banks. International collaboration has also been well-improved in this field. Nowadays, almost all patients who need allogeneic transplantation are able to find adequate donors. Advantages to use CB unit are the quick availability, lower risk of severe graft-versus-host disease (GVHD) even though HLA between recipients and CB grafts is mismatched in most cases, and no risk for CB donors medically and mentally. Since the first patient received the CB from his HLA-matched sister to treat Fanconi Anemia successfully in 1988 [2], many CB banks have been established and the numbers of transplants using unrelated CB units dramatically increased. There are approximately 621,000 CB units in the database of Bone Marrow Donors Worldwide (BMDW: http://www.bmdw.org/). Recently, more than 3,000 CB transplantation (CBT)s are carried out annually all over the world: one third in Europe, one third in North America and another one third in Asia (mostly in Japan). Pediatric patients were major users in early period, however, CBT are gradually adopted in adults in this decade. For example, we are performing more than 1,200 transplantations using single CB unit annually in Japan, and more than 80% are adult patients with hematology malignancies, and a half of the recipients are older than 50 years. The major reason of this increment in the world is the improved clinical outcomes. Recently, for example, Eapen and colleagues [3] compared results of 165 single CBT for adult patients, 888 peripheral blood stem cell transplant (PBSCT) patients, and 472 bone marrow transplant (BMT) patients. Transplant-related mortality was higher for the CBT patients, but chronic GVHD were lower. Leukemia-free survival was comparable among CBT, fully matched, and mismatched PBSCT/BMT patients [3]. These findings have contributed to increase the CBT activity among the international transplant societies and have gradually improved the reliability of this transplant strategy. There is still limitation in CBT such as delayed engraftment and poor immune cell reconstitution [4]. The quality assurance of CB unit is also key issue for the reliability of CBT among the patients, their families, and transplant physicians. Cell dose is the most significant parameters for engraftment capacity of CB unit and also for survival results after CBT. Especially, CD34-positive cell number indicates the hematopoietic stem or progenitor cell function. However, the diversity of technical difference between CB banks has been evoked and it is necessary that we adjust that standard. Efforts are being intensified by the Foundation for the Accreditation of Cellular Therapy and the Joint Accreditation Committee - International Society for Cellular Therapy and European Group for Blood and Marrow Transplantation (FACT-JACIE), the American Association of Blood Banks (AABB), and CB banks all over the world. Because the importance of cell dose is critical, researchers are focusing on CB expansion strategies and some of them are under laboratory and clinical assessment. Under the situation described as above, CBT is definitely contributing to improving the life prognosis of patients with hematological malignancies. On the other hand, the utilized percentage of donated CB units all over the world is 6.3% reported by World Marrow Donor Association (WMDA), however it was reported as 1.2% in Korea. In this issue of Blood Research, Choi et al. [5] has analyzed the reasons by the questionnaire survey using Audience Response System for 67 board-certified transplant physicians at the annual meeting of the Korean Society of Blood and Marrow Transplantation. According to ordinary expectations, Korean physicians are now not positive for choose CB units as stem cell source for transplantation, because of the fears for poor clinical results and for unsatisfied quality of CB units from domestic CB banks. However, some Korean transplant specialists and CB bank persons have continued to proceed with great efforts for achieving the satisfied clinical outcomes with CBT and for obtaining good enough quality of CB units. They have already known the education is also important to improve the reliabilities for the strategy. Please just remember the time when you started BMT or PBSCT, or even transplant with haplo just a couple of years ago. Nothing gains without going forward. Here comes the time of CBT.

Identification Of CD34+ Microparticles In Cord Blood Units

Introduction Cell-derived microparticles (MPs), small membrane vesicles, are considered as markers of cell activation, as well as apoptosis and recently was shown to participate in important normal biological functions and pathological conditions associated mainly with endothelial injury, thrombosis and inflammation. Recently platelet MPs have been detected in patients undergoing allogeneic stem cell transplantation. Umbilical cord blood is an alternative stem cell source for transplantation where the presence of MPs has not been extensively studied. The aim of this study is to quantify the MPs of CD34+ cells in cord blood units and to investigate their relationship with different parameters. Methods Cord blood units (CBUs) (n=41) were processed using the Sepax automated method (Biosafe). After processing, cryopreservation was performed using 10% DMSO in a controled rate freezer (IceCube, Sy-lab). Units were thawed after two weeks. Adjusted variables of the CBUs included their net volume, the absolute number of CD34+ per graft and their viability as determined by flow cytometry, the number of leukocytes as recorded with an hematology analyzer and the absolute number of erythroblasts as estimated by optical microscope after Giemsa staining. Mononuclear cells were seeded in semisolid cultures in the presence of a cocktail of growth factors for colony forming unit granulocyte/macrophage (CFU-GM), burst forming unit erythroid (BFU-E) and Colony-Forming Unit-Granulocyte, Erythrocyte, Monocyte/macrophage, Megakaryocyte (CFU-GEMM) colony growth. The MPs were isolated after centrifugation of the plasma and their number was determined after incubation with Annexin V and CD34 by flow cytometry. Electron microscope photographs were obtained, after the proceedings for TEM. Statistical analysis was done using t-test, Pearson's and Spearman's depending on the normality of the distribution of variables. Results The mean number of AnnV+/CD34+MPs increased during post-processing (76,7±15,9) compared to the number of pre-processing AnnV+/CD34+MPs (73±22 ) and decreased during post-thawing (52,4 ±16,7). On univariate analysis found that the number of AnnV+/CD34+MPs (pre-processing vs. post-processing) has statistically significant mean positive correlation (p<0,012, Pearson's rho =0,823) whereas the number of MPs post-thawing was not statistically significant. Pre-processing AnnV+/CD34+MPs has statistically significant correlation with the absolute number of pre-processing CD34+ cell per unit (p<0,0001, Spearman's rho =0,835), post-processing (p<0,0001, Spearman's rho =0,814) and post-thawing CD34+ cells per unit (p<0,0001, Spearman's rho =0,993). Correlation of post-processing CFUs and AnnV+/CD34+MPs showed that the number of AnnV+/CD34+MPs has statistically significant mean negative correlation to the number of CFU-GEMM (p<0,028, Spearman's rho = -0,348). Conclusions These data confirm the identification of stem cell-derived MPs from cord blood samples. Moreover, the number of pre- and post- processing AnnV+/CD34+MPs was statistically correlated. In addition, the absolute number of CD34 (pre-, post- processing and post-thawing) was associated with the AnnV+/CD34+MPs pre- processing. Thus it remains to be shown if the stem cell derived MPs could be a useful parameter to predict the quality of the cord blood unit. Disclosures: No relevant conflicts of interest to declare.

Human Mesenchymal Precursor Cells (Stro-1+) from Spinal Cord Injury Patients Improve Functional Recovery and Tissue Sparing in an Acute Spinal Cord Injury Rat Model

This study aimed to determine the potential of purified (Stro-1(+)) human mesenchymal precursor cells (hMPCs) to repair the injured spinal cord (SC) after transplantation into T-cell-deficient athymic RNU nude rats following acute moderate contusive spinal cord injury (SCI). hMPCs were isolated from the bone marrow (BM) stroma of SCI patients and transplanted as a suspension graft in medium [with or without immunosuppression using cyclosporin A (CsA)]. Extensive anatomical analysis shows statistically significant improvement in functional recovery, tissue sparing, and cyst reduction. We provide quantitative assessment of supraspinal projections in combination with functional outcomes. hMPC-transplanted animals consistently achieved mean BBB scores of 15 at 8 weeks post injury. Quantitative histological staining revealed that graft-recipient animals possessed more intact spinal tissue and reduced cyst formation than controls. Fluorogold (FG) retrograde tracing revealed sparing/regeneration of supraspinal and local propriospinal axonal pathways, but no statistical differences were observed compared to controls. Immunohistochemical analysis revealed increased serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted donor hMPCs 2 weeks posttransplantation, but no evidence of hMPC transdifferentiation was seen. Although hMPCs initially survive at 2 weeks posttransplantation, their numbers were dramatically reduced and no cells were detected at 8 weeks posttransplantation using retroviral/lentiviral GFP labeling and a human nuclear antigen (HNA) antibody. Additional immunosuppression with CsA did not improve hMPC survival or their ability to promote tissue sparing or functional recovery. We propose Stro-1(+)-selected hMPCs provide (i) a reproducible source for stem cell transplantation for SC therapy and (ii) a positive host microenvironment resulting in the promotion of tissue sparing/repair that subsequently improves behavioral outcomes after SCI. Our results provide a new candidate for consideration as a stem cell therapy for the repair of traumatic CNS injury.

Twenty years of experience on stem cell transplantation in iran.

BackgroundHematopoietic stem cell transplantation (HSCT) is a new window to therapy of many diseases. From March 1991 through April 2011, a total of 3237 HSCT were performed in the Hematology-Oncology and Stem Cell Transplantation Research Center, affiliated to Tehran University of Medical Sciences. Here we report 20 years experience of HSCT.ObjectivesOur strategy and aim include the protraction of cytogenetic and molecular biological diagnostic tests, the expansion of the first Iranian Cord Blood Bank (ICBB) and development of the first Iranian Stem Cell Donor Program (ISCDP), and improvement the researches in new therapeutic fields.Patients and MethodsTotally, 3237 patients were undergone HSCT. Of these transplants, 2205 were allogeneic stem cell transplantation, 1016 autologous and 16 syngeneic. Among 2205 patients who were undergone allogenic-HSCT, 34 received cord blood stem cells as stem cell source for transplantation. It is important to point out that cord blood bank at our center provides reliable storage of cord blood stem cells for our patients. Stem cell transplantation was performed for treatment of various diseases such as acute myelogenous leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, chronic lymphoblastic leukemia, beta-thalassemia major, sickle- cell thalassemia, sickle- cell disease, multiple myeloma, myelodysplasia, mucopolysaccharidosis, paroxysmal nocturnal hemoglobinuria, non-Hodgkin’s lymphoma, Hodgkin’s disease, severe aplastic anemia, plasma cell leukemia, Niemann-Pick disease, Fanconi anemia, severe combined immunodeficiency, congenital neutropenia, leukocyte adhesion deficiencies, Chediak-Higashi syndrome, osteopetrosis, histiocytosis X, Hurler syndrome, amyloidosis, systemic sclerosis, breast cancer, Ewing's sarcoma, testicular cancer, germ cell tumors, neuroblastoma, medulloblastoma, renal cell carcinoma, nasopharyngeal carcinoma, ovarian cancer, Wilms’ tumor, rhabdomyosarcoma, pancreatoblastoma, and multiple sclerosis. Also, we had 220 cellular therapies for post-myocardial infarction, multiple sclerosis, cirrhosis, head of femur necrosis, Diabetes Mellitus and GvHD treatment. 45 patients were undergone retransplantation in this center.ResultsAbout 78.2% of the patients (2530 of 3237) remained alive between one to 211 months after stem cell transplantation. Nearly, 21.8% (707) of our patients died after stem cell transplantation. The main causes of death were relapse, infection, hemorrhagic cystitis, graft-versus- host disease and etc.ConclusionsIn Iran, HSCT has been successfully adapted in routine clinical care. Recently, new methods such as double cord blood and haploidentical transplantation have been used to treat many life-threatening diseases.