Laminin and Platelet-Derived Growth Factor-BB Promote Neuronal Differentiation of Human Urine-Derived Stem Cells

Urine-derived stem cells (USCs) are considered as a promising cell source capable of neuronal differentiation. In addition, specific growth factors and extracellular matrix are essential for enhancing their neuronal differentiation efficiency. In this study, we investigated the possibility of neuronal differentiation of USCs and the role of laminin and platelet-derived growth factor BB (PDGF-BB) as promoting factors. USCs were isolated from fresh urine of healthy donors. Cultured USCs were adherent to the plate and their morphology was similar to the cobblestone. In addition, they showed chromosome stability, rapid proliferation rate, colony forming capacity, and mesenchymal stem cell characteristics. For inducing the neuronal differentiation, USCs were cultured for 14 days in neuronal differentiation media supplemented with/without laminin and/or PDGF-BB. To identify the expression of neuronal markers, RT-PCR, flow cytometry analysis and immunocytochemistry were used. After neuronal induction, the cells showed neuron-like morphological change and high expression level of neuronal markers. In addition, laminin and PDGF-BB respectively promoted the neuronal differentiation of USCs and the combination of laminin and PDGF-BB showed a synergistic effect for the neuronal differentiation of USCs. In conclusion, USCs are noteworthy cell source in the field of neuronal regeneration and laminin and PDGF-BB promote their neuronal differentiation efficiency.

The Efficacy and Safety of Collagen-I and Hypoxic Conditions in Urine-Derived Stem Cell Ex Vivo Culture

Upper urinary tract-derived urine stem cells (USCs) are considered a valuable mesenchymal stem cell source for autologous cell therapy. However, the reported culture condition for USCs is not appropriate for large-quantity production, because cells can show limited replicativity, senescence, and undesirable differentiation during cultivation. These drawbacks led us to reconstitute a culture condition that mimics the natural stem cell niche. We selected extracellular matrix protein and oxygen tension to optimize the ex vivo expansion of USCs, and compared cell adhesion, proliferation, gene expression, chromosomal stability, differentiation capacity, immunity and safety. Culture on collagen type I (ColI) supported highly enhanced USC proliferation and retention of stem cell properties. In the oxygen tension analysis (with ColI), 5% O₂ hypoxia showed a higher cell proliferation rate, a greater proportion of cells in the S phase of the cell cycle, and normal stem cell properties compared to those observed in cells cultured under 20% O₂ normoxia. The established reconstituted condition (ColI/hypoxia, USCs(recon)) was compared to the control condition. The expanded USCs(recon) showed highly increased cell proliferation and colony forming ability, maintained transcription factors, chromosomal stability, and multi-lineage differentiation capacity (neuron, osteoblast, and adipocyte) compared to the control. In addition, USCs(recon) retained their immune-privileged potential and non-tumorigenicity with in vivo testing at week 8. Therefore, reconstituted condition allows for expanded uUSC cell preparations that are safe and useful for application in stem cell therapy.

Comparing the osteogenic potential of canine mesenchymal stem cells derived from adipose tissues, bone marrow, umbilical cord blood, and Wharton's jelly for treating bone defects

Alternative sources of mesenchymal stem cells (MSCs) for replacing bone marrow (BM) have been extensively investigated in the field of bone tissue engineering. The purpose of this study was to compare the osteogenic potential of canine MSCs derived from adipose tissue (AT), BM, umbilical cord blood (UCB), and Wharton's jelly (WJ) using in vitro culture techniques and in vivo orthotopic implantation assays. After canine MSCs were isolated from various tissues, the proliferation and osteogenic potential along with vascular endothelial growth factor (VEGF) production were measured and compared in vitro. For the in vivo assay, MSCs derived from each type of tissue were mixed with beta-tricalcium phosphate and implanted into segmental bone defects in dogs. Among the different types of MSCs, AT-MSCs had a higher proliferation potential and BM-MSCs produced the most VEGF. AT-MSCs and UCB-MSCs showed greater in vitro osteogenic potential compared to the other cells. Radiographic and histological analyses showed that all tested MSCs had similar osteogenic capacities, and the level of new bone formation was much higher with implants containing MSCs than cell-free implants. These results indicate that AT-MSCs, UCB-MSCs, and WJ-MSCs can potentially be used in place of BM-MSCs for clinical bone engineering procedures.

Hematopoietic Stem Cell Transplantation in Pediatric Acute Myelogenous Leukemia: Relevance of the Stem Cell Source to the Transplant Outcome / 대한혈액학회지

BACKGROUND: Postremission therapy is critical for achieving long-term survival in the patients with acute myelogenous leukemia (AML). Allogeneic bone marrow transplantation during the first complete remission (CR) with using a HLA-identical sibling donor may offer the best chance for long-term leukemia-free survival. The patients without matched siblings have several treatment options. The aim of this study was to compare the clinical outcomes after matched sibling transplantation (MST), unrelated stem cell transplantation (non-MST), or autologous peripheral blood stem cell transplantation (APBSCT) as a postremission therapy for children with AML. METHODS: Thirty four hematopoietic stem cell transplantations (SCT) in 32 children with AML were performed between June, 1996 and December, 2004. Two patients who failed at prior APBSCT underwent a 2nd unrelated transplantations. The disease status at the time of transplantation, the conditioning regimen, prophylaxis for graft-versus-host disease (GVHD), the incidence of GVHD, complications, the cause of death, the over-all survival and the event-free survival were retrospectively compared in relation to the stem cell sources. RESULTS: There were 19 males and 13 females with a median age of 8 yr 10 mo. The median follow-up was 17 mo. Twenty-eight cases were transplanted during CR1. Most (5/6) of patients other than the patients who were in CR1 were allocated in the non-MST group. APBSCT was done in 17 cases, and allo-transplants were done in 17 cases, which included MSTs in 10, matched-unrelated BM transplants in 5, haploidentical CD34+selected peripheral blood transplant in 1, and 1-antigen mismatch unrelated cord blood transplantation in 1. Acute GvHD > or = than Grade 2 was found in 20% of the MST cases vs. 85.7% in the non-MST cases (P<.01). The two-year cumulative relapse risks were 46.4% in the APBSCT cases, 20% in the MST cases and 31.5% in the non-MST cases. The Kaplan-Meier 2-year EFS in all cases was 55.7%: 46.3% in the APBMT cases, 80.0% in the MST cases and 68.6% in the non-MST cases, despite the higher proportion of high risk patients in the non-MST group. CONCLUSION: This study indicated that MST was the best option for pediatric AML. For patients without matched siblings, the patients with unrelated transplants fared better, had better survival and a lower relapse rate than the APBSCT patients. However, a further prospective, randomized study that incorporates a larger number of patients and a cord blood transplant arm is necessary to definitely determine the best option for pediatric AML.

Tissue engineering of the bladder and its medical ethical conflicts / 医学研究生学报

During the last decade,tissue engineering techniques,including the preparation of scaffold and cell culture,have undergone significant development and achieved encouraging results in preliminary clinical trails.However,many medical ethical conflicts still lie ahead in the tissue engineering of the bladder for clinical applications.This review focuses on the current status of tissue engineering techniques and proposes some fundamental principles to be followed in the clinical application of tissue engineering of the bladder.

Outcomes of Hematopoietic Stem Cell Transplantation with Different Stem Cell Sources in Children with Malignant and Non-malignant Hematologic Diseases / 대한소아혈액종양학회지

PURPOSE: We compared the clinical outcomes of allogeneic bone marrow transplantation (BM), peripheral blood stem cell transplantation (PB) and cord blood stem cell transplantation (CB) in children with malignant and non-malignant diseases. METHODS: We retrospectively analysed the engraftment speed, episodes of infection, acute graft versus host disease (GVHD), and survival rate in 27 children who underwent hematopoietic stem cell transplantation (HSCT) at Dong-A Cancer Center from August 1998 to July 2001. RESULTS: HSCT were done with BM in 16 patients, CB in 6 and PB in 5. The neutrophil and platelet engraftment were achieved at 13.27+/-4.10, 24.58+/-9.41 days in BM, 12.00+/-1.09, 15.88+/-4.42 days in PB, and 39.00+/-15.68, 76.50+/-37.01 days in CB (P=0.001, P=0.001). There were 17 episodes of bacteremia and 10 episodes of viral infections without any significant differences between stem cell sources. There were 8 cases (7 in BM, 1 in CB) of acute GVHD, 4 cases (2 in BM, 2 in CB) of graft failure and 3 cases of relapse (1 in BM, 2 in CB) after HSCT. The duration of median follow-up was 14.34+/-8.32 months in BM, 11.43+/-10.03 months in PB, and 16.56+/-13.76 months in CB. The overall and event free survival rate were 81.5% and 63.0%, respectively. CONCLUSION: There were no significant differences in episodes of infection between the types of HSCT. Although there were HLA mismatched donors for CB, the incidence of acute GVHD was lower, and graft failure or relapse rate was higher than BM.