Alternative Cell Source Research Articles

Alternative donors provide comparable results to matched unrelated donors in patients with acute lymphoblastic leukemia undergoing allogeneic stem cell transplantation in second complete remission: a report from the EBMT Acute Leukemia Working Party.

Relapse of acute lymphoblastic leukemia (ALL) remains a major therapeutic challenge. Despite the consensus for proceeding to allogeneic stem cell transplantation (HSCT) in relapsing patients with ALL who achieve second complete remission (CR2) with salvage therapy, most patients lack a suitable matched-related histocompatible donor. The present multicenter retrospective study compared, for ALL patients in CR2, the HSCT outcome from all four possible alternative hematopoietic stem cell sources, namely matched unrelated 10/10 (n = 281), mismatched unrelated 9/10 (n = 125), haploidentical (n = 105), and cord blood (n = 104) donors. The 2-year outcomes were not statistically different between the four donor sources with respect to overall survival (38.3-47.2%), leukemia-free survival (30.5-39.6%), relapse incidence (32.6-37.6%), nonrelapse mortality (27.5-34.6%), and graft-versus-host disease-free relapse survival (21.4-33.1%). Donor choices for ALL patients achieving CR2 post first relapse are broad, ensuring that most patient in need secures a graft. Therefore, in practice, the donor choice should depend on timely availability and policy center.

Prospective evaluation of alternative donor from unrelated donor and cord blood in adult acute leukemia and myelodysplastic syndrome.

A prospectively registered observational study was conducted to assess the significance of allogeneic hematopoietic stem cell transplantation from highly HLA-matched unrelated donors (UD) and cord blood (CB) on outcomes in adult acute leukemia (AL) and myelodysplastic syndrome (MDS). Between 2007 and 2015, 231 transplant-eligible patients were registered for a phase 2 study of alternative donor transplantation. After registration, a sufficient time period was given to find appropriate UD. Patients received CB transplantation (CBT) if an appropriate UD was unavailable. In total, 119 patients received CBT (106 AL and 13 MDS) and 91 patients received UD transplantation (UDT) (86 AL and 5 MDS). The median age was 39 years in both groups. The primary objective was overall survival (OS); secondary objectives included cumulative incidences of non-relapse mortality (NRM) and relapse, and disease-free survival. Diagnosis, disease status at transplantation, refined disease risk index, and hematopoietic cell transplant-specific comorbidity index did not differ between UDT and CBT. In multivariate analyses, graft source was not a significant risk factor for all objectives. In adjusted analyses, UDT and CBT showed similar OS, NRM, and relapse in this prospective study. CB can be a comparable alternative stem cell source to UD by achieving a timely transplant.

Costal Chondrocyte–Derived Pellet-Type Autologous Chondrocyte Implantation for Treatment of Articular Cartilage Defect

Background: Because articular chondrocyte-based autologous chondrocyte implantations (ACIs) have restrictively restored articular cartilage defects, alternative cell sources as a new therapeutic option for cartilage repair have been introduced. Purpose: To assess whether implantation of a costal chondrocyte–derived pellet-type (CCP) ACI allows safe, functional, and structural restoration of full-thickness cartilage defects in the knee. Study Design: Case series; Level of evidence, 4. Methods: In this first-in-human study, 7 patients with symptomatic, full-thickness cartilage lesions were enrolled. The chondrocytes isolated from the patients’ costal cartilage were expanded, followed by 3-dimensional pellet culture to prepare the CCP-ACI. Implantation of the pellets was performed via minimal arthrotomy and secured with a fibrin sealant. Clinical scores, including the International Knee Documentation Committee (IKDC) subjective, Lysholm, and Tegner activity scores, were estimated preoperatively and at 1, 2, and 5 years postoperatively. High-resolution magnetic resonance imaging was also performed to evaluate cartilage repair as well as to calculate the MOCART (magnetic resonance observation of cartilage repair tissue) score. Results: The costal chondrocytes of all patients formed homogeneous-sized pellets, which showed the characteristics of the hyaline cartilaginous tissue with lacunae-occupied chondrocytes surrounded by glycosaminoglycan and type II collagen-rich extracellular matrix. There were no treatment-related serious adverse events during the 5-year follow-up period. Significant improvements were seen in all clinical scores from preoperative baseline to the 5-year follow-up (IKDC subjective score, 34.67 to 75.86; Lysholm score, 34.00 to 85.33; Tegner activity score, 1.17 to 4.67; and MOCART score, 28.33 to 83.33). Two patients had complete defect filling on magnetic resonance imaging evaluation at 1 year. Moreover, at 5 years postoperatively, complete defect filling was observed in 4 patients, and hypertrophy or incomplete defect filling (50%-100%) was observed in 2 patients. Conclusion: The overall results of this clinical study suggest that CCP-ACI can emerge as a promising therapeutic option for articular cartilage repair with good clinical outcomes and structural regeneration and with stable results at midterm follow-up. Registration: NCT03517046 (ClinicalTrials.gov identifier)

Efficient differentiation and purification of human induced pluripotent stem cell-derived endothelial progenitor cells and expansion with the use of inhibitors of ROCK, TGF-β, and GSK3β

Endothelial cells (ECs) and endothelial progenitor cells (EPCs) play crucial roles in maintaining vascular health and homeostasis. Both cell types have been used in regenerative therapy as well as in various in vitro models; however, the properties of primary human ECs and EPCs are dissimilar owing to differences in genetic backgrounds and sampling techniques. Human induced pluripotent stem cells (hiPSCs) are an alternative cell source of ECs and EPCs. However, owing to the low purity of differentiated cells from hiPSCs, purification via an antigen–antibody reaction, which damages the cells, is indispensable. Besides, owing to limited expandability, it is difficult to produce these cells in large numbers. Here we report the development of relatively simple differentiation and purification methods for hiPSC-derived EPCs (iEPCs). Furthermore, we discovered that a combination of three small molecules, that is, Y-27632 (a selective inhibitor of Rho-associated, coiled-coil containing protein kinase [ROCK]), A 83–01 (a receptor-like kinase inhibitor of transforming growth factor beta [TGF-β]), and CHIR-99021 (a selective inhibitor of glycogen synthase kinase-3β [GSK3β] that also activates Wnt), dramatically stimulated protein synthesis-related pathways and enhanced the proliferative capacity of iEPCs. These findings will help to establish a supply system of EPCs at an industrial scale.

Research progresses of the way to improve umbilical cord blood stem cells homing and engraftment

Umbilical cord blood is an alternative hematopoietic stem cell source has been widely recognized. Initially, umbilical cord blood transplantation was limited, given the low engraftment. So the method of improving cord blood homing and engraftment has been widely studied in various fields. This paper briefly reviews the progress of main researches in recent years. Key words: Cord blood stem cell transplantation; Homing; Engraftment; Review

Alternative Cell Sources for Liver Parenchyma Repopulation: Where Do We Stand?

Acute and chronic liver failure is a highly prevalent medical condition with high morbidity and mortality. Currently, the therapy is orthotopic liver transplantation. However, in some instances, chiefly in the setting of metabolic diseases, transplantation of individual cells, specifically functional hepatocytes, can be an acceptable alternative. The gold standard for this therapy is the use of primary human hepatocytes, isolated from livers that are not suitable for whole organ transplantations. Unfortunately, primary human hepatocytes are scarcely available, which has led to the evaluation of alternative sources of functional hepatocytes. In this review, we will compare the ability of most of these candidate alternative cell sources to engraft and repopulate the liver of preclinical animal models with the repopulation ability found with primary human hepatocytes. We will discuss the current shortcomings of the different cell types, and some of the next steps that we believe need to be taken to create alternative hepatocyte progeny capable of regenerating the failing liver.

Generation of human androgenetic induced pluripotent stem cells

In humans, parthenogenesis and androgenesis occur naturally in mature cystic ovarian teratomas and androgenetic complete hydatidiform moles (CHM), respectively. Our previous study has reported human parthenogenetic induced pluripotent stem cells from ovarian teratoma–derived fibroblasts and screening of imprinted genes using genome-wide DNA methylation analysis. However, due to the lack of the counterparts of uniparental cells, identification of new imprinted differentially methylated regions has been limited. CHM are inherited from only the paternal genome. In this study, we generated human androgenetic induced pluripotent stem cells (AgHiPSCs) from primary androgenetic fibroblasts derived from CHM. To investigate the pluripotency state of AgHiPSCs, we analyzed their cellular and molecular characteristics. We tested the DNA methylation status of imprinted genes using bisulfite sequencing and demonstrated the androgenetic identity of AgHiPSCs. AgHiPSCs might be an attractive alternative source of human androgenetic embryonic stem cells. Furthermore, AgHiPSCs can be used in regenerative medicine, for analysis of genomic imprinting, to study imprinting-related development, and for disease modeling in humans.

Urine as a Main Effector in Urological Tissue Engineering-A Double-Edged Sword.

In order to reconstruct injured urinary tract tissues, biodegradable scaffolds with autologous seeded cells are explored in this work. However, when cells are obtained via biopsy from individuals who have damaged organs due to infection, congenital disorders, or cancer, this can result in unhealthy engineered cells and donor site morbidity. Thus, neo-organ construction through an alternative cell source might be useful. Significant advancements in the isolation and utilization of urine-derived stem cells have provided opportunities for this less invasive, limitless, and versatile source of cells to be employed in urologic tissue-engineered replacement. These cells have a high potential to differentiate into urothelial and smooth muscle cells. However, urinary tract reconstruction via tissue engineering is peculiar as it takes place in a milieu of urine that imposes certain risks on the implanted cells and scaffolds as a result of the highly cytotoxic nature of urine and its detrimental effect on both growth and differentiation of these cells. Both of these projections should be tackled thoughtfully when designing a suitable approach for repairing urinary tract defects and applying the needful precautions is vital.

Intra-individual comparison of human nasal chondrocytes and debrided knee chondrocytes: Relevance for engineering autologous cartilage grafts.

Implantation of autologous chondrocytes for cartilage repair requires harvesting of undamaged cartilage, implying an additional joint arthroscopy surgery and further damage to the articular surface. As alternative possible cell sources, in this study we assessed the proliferation and chondrogenic capacity of debrided Knee Chondrocytes (dKC) and Nasal Chondrocytes (NC) collected from the same patients. Matched NC and dKC pairs from 13 patients enrolled in two clinical studies (NCT01605201 and NCT026739059) were expanded in monolayer and then chondro-differentiated in 3D collagenous scaffolds in medium with or without Transforming Growth Factor beta 1 (TGFβ1). Cell proliferation and amount of cartilage matrix production by these two cell types were assessed. dKC exhibited an inferior proliferation rate than NC, and a lower capacity to chondro-differentiate. Resulting dKC-grafts contained lower amounts of cartilage specific matrix components glycosaminoglycans and type II collagen. The cartilage forming capacity of dKC did not significantly correlate with specific clinical parameters and was only partially improved by medium supplemention with TGFβ1. dKC exhibit a reproducibly poor capacity to engineer cartilage grafts. Our in vitro data suggest that NC would be a better suitable cell source for the generation of autologous cartilage grafts.

High-Resolution Dissection of Chemical Reprogramming from Mouse Embryonic Fibroblasts into Fibrocartilaginous Cells.

SummaryArticular cartilage injury and degeneration causing pain and loss of quality-of-life has become a serious problem for increasingly aged populations. Given the poor self-renewal of adult human chondrocytes, alternative functional cell sources are needed. Direct reprogramming by small molecules potentially offers an oncogene-free and cost-effective approach to generate chondrocytes, but has yet to be investigated. Here, we directly reprogrammed mouse embryonic fibroblasts into PRG4+ chondrocytes using a 3D system with a chemical cocktail, VCRTc (valproic acid, CHIR98014, Repsox, TTNPB, and celecoxib). Using single-cell transcriptomics, we revealed the inhibition of fibroblast features and activation of chondrogenesis pathways in early reprograming, and the intermediate cellular process resembling cartilage development. The in vivo implantation of chemical-induced chondrocytes at defective articular surfaces promoted defect healing and rescued 63.4% of mechanical function loss. Our approach directly converts fibroblasts into functional cartilaginous cells, and also provides insights into potential pharmacological strategies for future cartilage regeneration.

Functional expression of ZNF467 and PCBP2 supports adipogenic lineage commitment in adipose-derived mesenchymal stem cells

Bone marrow-derived mesenchymal stromal/stem cells (BMSCs) have the potential to be employed in many different skeletal therapies. A major limitation to utilizing BMSCs as a therapeutic strategy in human disease and tissue regeneration is the low cell numbers obtained from initial isolation necessitating multiple cell passages that can lead to decreased cell quality. Adipose-derived mesenchymal stromal/stem cells (AMSCs) have been proposed as an alternative cell source for regenerative therapies; however the differentiation capacity of these cells differs from BMSCs. To understand the differences between BMSCs and AMSCs, we compared the global gene expression profiles of BMSCs and AMSCs and identified two genes, PCBP2 and ZNF467 that were differentially expressed between AMSCs and BMSCs. We demonstrate that PCBP2 and ZNF467 impact adipogenic but not osteogenic differentiation, further supporting evidence that AMSCs and BMSCs appear to be adapted to their microenvironment.

Mesenchymal stem cells derived from iPSCs expressing interleukin-24 inhibit the growth of melanoma in the tumor-bearing mouse model

BackgroundInterleukin-24 (IL-24) is a therapeutic gene for melanoma, which can induce melanoma cell apoptosis. Mesenchymal stem cells (MSCs) show promise as a carrier to delivery anti-cancer factors to tumor tissues. Induced pluripotent stem cells (iPSCs) are an alternative source of mesenchymal stem cells (MSCs). We previously developed a novel non-viral gene targeting vector to target IL-24 to human iPSCs. This study aims to investigate whether MSCs derived from the iPSCs with the site-specific integration of IL-24 can inhibit the growth of melanoma in a tumor-bearing mouse model via retro-orbital injection.MethodsIL-24-iPSCs were differentiated into IL-24-iMSCs in vitro, of which cellular properties and potential of differentiation were characterized. The expression of IL-24 in the IL-24-iMSCs was measured by qRT-PCR, Western Blotting, and ELISA analysis. IL-24-iMSCs were transplanted into the melanoma-bearing mice by retro-orbital intravenous injection. The inhibitory effect of IL-24-iMSCs on the melanoma cells was investigated in a co-culture system and tumor-bearing mice. The molecular mechanisms underlying IL-24-iMSCs in exerting anti-tumor effect were also explored.ResultsiPSCs-derived iMSCs have the typical profile of cell surface markers of MSCs and have the ability to differentiate into osteoblasts, adipocytes, and chondroblasts. The expression level of IL-24 in IL-24-iMSCs reached 95.39 ng/106 cells/24 h, which is significantly higher than that in iMSCs, inducing melanoma cells apoptosis more effectively in vitro compared with iMSCs. IL-24-iMSCs exerted a significant inhibitory effect on the growth of melanoma in subcutaneous mouse models, in which the migration of IL-24-iMSCs to tumor tissue was confirmed. Additionally, increased expression of Bax and Cleaved caspase-3 and down-regulation of Bcl-2 were observed in the mice treated with IL-24-iMSCs.ConclusionMSCs derived from iPSCs with the integration of IL-24 at rDNA locus can inhibit the growth of melanoma in tumor-bearing mouse models when administrated via retro-orbital injection.

Seven Years of Haplo-Cord Transplantation: Immune Reconstitution and Outcomes Using Anti-Thymocyte Globulin

Introduction Haplo-cord transplantation – the co-infusion of a single cord unit with CD34-selected cells from a haplo-identical donor, provides an alternate stem cell source for patients lacking HLA-matched donors. Anti-thymocyte globulin (ATG) is routinely used in haplo-cord preparative regimens to reduce graft failure, graft vs. host disease (GVHD) and graft vs. graft reactions. However, excessive depletion of cord lymphocytes may compromise immune reconstitution and graft vs. tumor (GVT) effects. Methods We reviewed lymphocyte recovery and outcome data for consecutive patients with hematologic malignancy who underwent haplo-cord transplantation at Weill Cornell Medicine between June 2012 and June 2019. All were conditioned using fludarabine and melphalan with or without total body irradiation (200-600cGy). All received rabbit ATG (Thymoglobulin), initially at a total dose of 6mg/kg (2012-2013) and later at a total dose of 4.5mg/kg (2013 onward). Data was collected as part of study 01810588 registered at clinicaltrials.gov. Probabilities of relapse and non-relapse mortality (NRM) were generated using cumulative incidence estimates to accommodate competing risks. Probabilities of overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan-Meier estimates. Results Our study included 220 haplo-cord transplant recipients with a median age of 58 yrs (Range: 18 – 76 yrs). The majority had myeloid disease (AML – 54%, MDS/MPN – 19.5%, CML – 2%). Conditioning incorporated TBI for 120 patients (55%). ATG was dosed at 6mg/kg for 41 patients (19%). The median absolute lymphocyte count (ALC) at first ATG exposure was 0.4 × 10^9/L (IQR25-75: 0.2-0.7 × 10^9/L). The median patient weight was 75.5kg (IQR25-75: 65.4-89.9kg). Neutrophil and platelet engraftment occurred at a median of 12 days (IQR25-75: 10-16 days) and 22 days (IQR25-75: 17-35 days) respectively. Graft failure was observed in 16 patients (7%). Rapid early recovery of CD19+ lymphocytes, CD56+ natural killer cells and IgG levels was observed. T-cell recovery was delayed, with a gradual increase observed from Day 100 (Figure). Overall PFS and OS at 2 yrs were 30% (CI 24-37%) and 39% (CI 32-46%) respectively. The 2 yr cumulative incidence of NRM was 33% (+/- 3% SEM). The overall 2 yr incidence of relapse was 37% (+/- 3% SEM), however there was a significant difference in relapse incidence between patients treated with 6mg/kg ATG (54%) versus 4.5mg/kg (31.5%) (p=0.009). Conclusion Haplo-cord transplant facilitates early neutrophil engraftment with early normalization of B- and NK-lymphocytes. An observed delay in T-cell recovery may be due to the use of ATG in this platform and higher ATG doses result in a greater incidence of relapse. Our data supports the minimization or replacement of ATG in haplo-cord transplant. An analysis of GVHD incidence and viral reactivation events is ongoing and will be presented.

Pro-elastogenic effects of mesenchymal stem cell derived smooth muscle cells in a 3D collagenous milieu

Intrinsically poor auto-regenerative repair of proteolytically-disrupted elastic matrix structures by resident SMCs in the wall of abdominal aortic aneurysms (AAAs) prevents growth arrest and regression of these wall expansions. Supporting their possible future use in a regenerative cell therapy for AAAs, in a prior study, we showed that bone marrow mesenchymal stem cell-derived Smooth Muscle Cells (BM-SMCs) secrete biological factors that have significant pro-elastogenic and anti-proteolytic effects on aneurysmal rat aortic SMCs (EaRASMCs) in non-contact co-cultures. We also identified one stable BM-SMC phenotype (cBM-SMC) generated by differentiating BM-MSCs on a 2D fibronectin substrate in the presence of PDGF (Platelet Derived Growth Factor) and TGF-β1 (Transforming Growth Factor-β1) that exhibited superior elastogenicity and pro-elastogenic/anti-proteolytic properties. In this study, we further investigated the ability of these cBM-SMCs to maintain these superior elastogenic properties in a 3D collagenous milieu alone and in co-culture with EaRASMC to evaluate their potential as an alternative cell source for cell therapy in AAA. Some of our key observations were higher contractility and greater amount of structurally intact elastin production in both standalone culture of cBM-SMCs as well as co-culture of cBM-SMCs with EaRASMCs as shown by VVG (Verhoeff-Van Gieson) staining and Pontamine Sky Blue labeling and lower MMP-9 protein expression in standalone culture in 3D collagenous environment. Our overall result indicates that cBM-SMCs possess the ability to provide elastogenic impetus in a 3D collagenous AAA milieu which is otherwise not conducive to elastogenesis. Therefore our study strongly suggest the utility of cBM-SMCs as a potential cell source for cell therapy to augment elastic matrix neo-assembly and fiber formation and attenuate proteolysis in a collagenous milieu that is evocative of the de-elasticized aneurysmal wall. Statement of SignificanceAbdominal aortic aneurysm (AAA) or ballooning of the aorta is one of the leading causes of cardiovascular disease (CVD) related death caused by significantly increased proteolytic activity in the aortic wall. Reversing pathophysiology of this condition is challenging due to intrinsically poor regeneration of elastin by aortic smooth muscle cells. Current management of AAA is limited to passive monitoring of the disease until it becomes large enough to receive surgical intervention and no drug based therapy currently exists. Cell based therapy can be a potential alternative treatment in this scenario because it provides elastogenic impetus to the aneurysmal SMCs, compensates for the dead SMCs and serves as a robust source of elastin while being delivered with minimal invasiveness. Hence this work will have significant impact in the field of tissue engineering and regenerative medicine.

Glycogen synthase kinase 3β inhibitor- CHIR 99021 augments the differentiation potential of mesenchymal stem cells

AimMesenchymal stem cells (MSCs) are immunomodulatory, non-teratogenic and multipotent alternatives to embryonic or induced pluripotent stem cells (ESCs or iPSCs). However, the potency of MSCs is not equivalent to the pluripotency of ESCs or iPSCs. We used CHIR 99021 to improve current protocols and methods of differentiation for the enhanced transdifferentiation potency of MSCs. Main MethodsWe used Flurescence activated cell sorter (FACS) for MSC immunophenotyping and biochemical assay for demonstrating the trilineage potential of MSCs. We used real-time polymerase chain reaction, immunocytochemistry and Western blotting assay for analyzing the expression of lineage-specific markers. Key FindingsCHIR 99021 treatment of MSCs resulted in enhanced transdifferentiation into neurological, hepatogenic and cardiomyocyte lineages with standardized protocols of differentiation. CHIR 99021–treated MSCs showed increased nuclear localization of β-catenin. These MSCs showed a significantly increased deposition of active histone marks (H3K4Me3, H3K36Me3), whereas no change was observed in repressive marks (H3K9Me3, H3K27Me3). Differential methylation profiling showed demethylation of the transcription factor OCT4 promoter region with subsequent analysis revealing increased gene expression and protein content. The HLA-DR antigen was absent in CHIR 99021–treated MSCs and their differentiated cell types, indicating their immune-privileged status. Karyotyping analysis showed that CHIR 99021–treated MSCs were genomically stable. Teratoma analysis of nude mice injected with CHIR 99021–treated MSCs showed the increased presence of cell types of mesodermal origin at the site of injection. SignificanceMSCs pretreated with CHIR 99021 can be potent, abundant alternative sources of stem cells with enhanced differentiation capabilities that are well suited to cell-based regenerative therapy.

Післязабійний кістковий мозок великої рогатої худоби – перспективне джерело стовбурових клітин

The development of modern methods of cryopreservation of animal cells has promoted to introduce the concept of creating of stem cell banks for their future use, to avoid problems with donor shortages. Large-scale cryopreservation of stem cells began in the 1990s with the establishment of human cord blood banks. The issue of long-term storage of stem cells is also acute in veterinary medicine. To obtain of cellular material, is needed a source suitable for cell isolation. As such a source it is advisable to consider a slaughter material from productive animals. The purpose of this study is to establish the possibility of cattle bone marrow use after slaughter as source of stem cells, on the basis of the proliferation index and the viability of the cultured cells to determine the suitability of this biological material for the obtaining of stem cells 72 hours after slaughter of the animal. Materials and methods. The bone marrow was obtained from the femur of a cow, 3 years old, who was slaughtered in a slaughterhouse. The bone marrow was collected with sterile tweezer into a sterile tube, filled with 0.25% trypsin solution (ratio of bone marrow volume to trypsin solution – 10: 1) and placed in a refrigerator (t + 4 0C) for 24 hours for enzymatic disaggregation. After bone marrow disaggregation, cultivation of cells was performed in a CO2-incubator using of disposable plastic Petri dishes (d = 30 mm) according to the standard procedure by periodically passaging them after forming a monolayer by 95–100%. Results. Cultivation of a suspension of cells, derived from the post-mortemal bone marrow of a cow, revealed that colonies of cells began to emerge 6–7 days after sowing. Passaging the cells with 0,25% trypsin-Versen solution and sowing them in new cultural plates contributed to increase the mass of cells that actively proliferated. It was established that stem cells, isolated from the post-mortemal bone marrow of cattle, have significant proliferative potential, as evidenced by proliferation indices  from I to III passages and high viability of cells. Thus, the post-mortemal bone marrow of the cattle can be used as an alternative source of stem cells. This biological material is suitable for the isolation of stem cells, even 72 hours after slaughtering the animal, which opens the prospects of its transportation over long distances.

Factors Associated With Umbilical Cord Blood Collection Quality in Japan.

BackgroundUmbilical cord blood (UCB) has become an established alternative source of hematopoietic stem cells with marrow and postmobilization peripheral blood. The presence of a large amount of clots may lead to the deterioration of cord blood quality. To improve UCB quality as a source of hematopoietic stem cells in Japan, we examined factors associated with UCB collection methods from the viewpoint of eliminating the presence of clots.MethodsIn August 2019, we requested the directors of 74 certified facilities to provide information on UCB collection methods in Japan. A total of 46 (62.2%) of them responded with valid information on a total of 2,892 UCB collections. In this study, collected UCB without clots macroscopically was evaluated as a high-quality UCB.ResultsThe 2,891 UCB collections described during the study period were divided to those with (n = 760, 26.3%) and without clots (high quality; n = 2,131, 73.7%). Multivariate analysis revealed single puncture as a factor determining high-quality UCB collection (adjusted odds ratio (ORs): 1.80, 95% confidence interval (CI): 1.3 - 5.4, P = 0.01).ConclusionsSingle puncture is an independent effective factor determining high-quality manual UCB collection in Japan.

Tissues from Post-Mortem Donors as Alternative Sources of Stem Cells for Regenerative Medicine.

Stem cells provide for all of the tissues in our body during embryogenesis. In adult organisms, they can be found as rare populations of tissue-specific stem cells in quiescent states, although they can still regenerate damaged tissues. Astonishingly, these cells are retained in tissues even post-mortem. There have been several reports that have provided evidence that cells with stem-like capabilities can be isolated, expanded, and differentiated in vitro from various tissues several hours, or even several days, post-mortem. Moreover, some post-mortem-tissue-derived stem cells can successfully engraft and regenerate injured host tissues. Here, we review in-vitro and in-vivo studies that provide evidence of isolation and characterization of stem cells from different tissues post-mortem, with a focus on the musculoskeletal and neural systems. Finally, we discuss their potential for use in regenerative medicine, and what needs to be done in further research toward their better exploitation.

Dopaminergic induction of human dental pulp stem cells by photobiomodulation: comparison of 660nm laser light and polychromatic light in the nir

Human dental pulp stem cells (hDPSCs) are able to differentiate into dopaminergic neurons and help the maintenance of partially degenerated neurons, which makes them as an alternative cell source for treatment of Parkinsons' disease (PD) patients. Here, the effect of photobiomodulation with polychromatic light source in the near infrared (NIR) range (600–1200 nm) or low level 660 nm diode laser light on hDPSCs during dopaminergic induction was investigated. Real time RT-qPCR analysis indicated that expressions of brain derived neurotrophic factor (BDNF), glial cell line derived neurotropic factor (GNDF), matrix associated protein 2 (MAP2), nuclear receptor related 1 protein (NURR1) and dopamine transporter (DAT) were increased, especially in the first 7 days of dopaminergic induction when 660 nm laser light was applied with a total energy density of 1.6 J/cm2. The activity of polychromatic light on hDPSCs depended on the differentiation media and protein type. BDNF, GDNF, NURR-1 and MAP2 expressions were increased in the presence of pre-induction factors, and decreased when the post-induction factors were added into the culture medium. In contrast with all these promising results, the dopaminergically induced hDPSCs did not show any functional characteristics of dopaminergic neurons and died after they were transferred to a new laminin coated culture plates. In conclusion, the expression of dopaminergic neuron protective protein mRNAs in hDPSCs was increased by photobiomodulation in defined conditions. However, the cells were not able to differentiate into functional dopaminergic neurons either in control or in photobiomodulated groups that are prone to cell death and exhibit immature dopaminergic neuron characteristics.

Natural Killer Cell Hypo-responsiveness in Chronic Lymphocytic Leukemia can be Circumvented In Vitro by Adequate Activating Signaling.

Chronic lymphocytic leukemia (CLL) is characterized by an acquired immune dysfunction, which may underlie the hampered efficacy of cellular immunotherapy. Most data on dampened immune responses in CLL come from studies investigating CLL and T cell interactions. Natural killer (NK) cells may be an attractive alternative source of effector cells in immunotherapy in CLL, provided that functionality is retained within the CLL micro-environment. Despite their important role in anti-tumor responses, NK cells are not extensively characterized in CLL. Here, we studied the expression of activating and inhibitory receptors on CLL-derived and healthy control (HC) NK cells, and their functional response towards several stimuli.NK cells from CLL patients have an increased maturation stage, with an expansion of NKG2C+ NK cells in CMV seropositive individuals. The cytotoxicity receptor NKG2D is downregulated, and the killing capacity through this receptor was markedly reduced in CLL-derived NK cells. In contrast, activation via CD16 (FCγRIII) led to adequate activation and functional responses in CLL-derived NK cells. These findings indicate that NK cells in CLL are not intrinsically defect and still perform effector functions upon adequate activating signaling. Clinical relevance of this finding was shown by treatment with novel nanobody-Fc constructs, which induced cytotoxic responses in both CLL- and HC-derived NK cells via CD16. Our results show that NK cells, in contrast to the T cell compartment, retain their function within the CLL micro-environment, provided that they receive an adequate activating signal. These findings warrant future studies on NK cell mediated immunotherapeutic strategies in CLL.