Immunophenotyping of hematopoietic progenitor cells: Comparison between cord blood and adult mobilized blood grafts

AIM:To study the immunophenotype of hematopoietic progenitor cells from cord blood (CB) grafts (n = 39) in comparison with adult apheresis grafts (AG, n = 229) and pre-apheresis peripheral blood (PAPB) samples (n = 908) using flow cytometry analysis.METHODS: First, we performed a qualitative analysis of CD34+ cell sub-populations in both CB and PAPB grafts using the standardized ISHAGE protocol and a wide panel of 20 monoclonal antibodies. Next, we stud-ied some parameters, such as the age of mothers and the weight of newborns, which can influence the qual-ity and the quantity of CD34+ cells from CB. RESULTS: We found that the percentage of apoptotic cells was high in CB in comparison to PAPB (PAPB: 4.6% ± 2.6% vs CB: 53.4% ± 5.2%, P < 0.001). In CB, the weight of newborn and the age of the mother have the influence on CD34+ cells. The follow-up of Ag CD133in the ISHAGE double platform protocol in association with CD45, CD34 and the 7’AAD shows an equal rate between the two cell populations CD133+CD45+CD34+ high and CD34+CD45+ high with a higher percentage. So, is the inclusion of Ac CD133 necessary in the pres-ent panel included in the ISHAGE methodflLast part, we showed a signif icant presence of interferon γ in CB in comparison to PAPB, the annexin showing the high number of apoptotic cells in CB. CONCLUSION: This study demonstrates that many different obstetric factors must be taken into account when processing and cryo-banking umbilical CB units for transplantation.

The invivo study of myeloprotection by GST-π gene transfected human cord blood hematopoietic stem cells transplantation

Objective :To investigate the influence of GST πgenetransferintohumancord blood hematopoie ticstem cellson their drugres is tanceagains tanti tumordrugs invivo .Methods: GST πgenetran sfectionin to human cord blood CD 34+cells was carried outusing are trovirusvec torPLJ GST πwith the aido f fibronect in .Succes sfulgenetransfer was confirmed by invitrocolony assay and RT PCR .GST πgenetrans duced human cord blood CD34+cells were the nengrafted in to 4 week old total body irradiated NOD/Scid mice and carboplatin was intraperitoneally admin is tered sequentially at 4 weeks interval 4 week saftereng raftment.Results :Peripheral blood (PB) WBC was significantly higher in GST πmice than control mice after 2 course of car boplat in .Retroviral GST π expression in bone marrow hematopoietic progenitor cells of recipient mice was detected by RT PCR 16 weeks after Xenotransplantation .Conclusion :The transfection of GST π gene could confer ,to some extent ,resistance to cord blood stem cells against carboplatin in vivo .

Effectiveness of repeated transplantations of hematopoietic stem cells in spinal cord injury

AIM: To evaluate the short and long-term effects of the complex cell therapy of 202 cases of spinal cord injury(SCI).METHODS: The main arm included 202 cases of SCI and the control arm included 20 SCI cases. For the therapy the hematopoietic stem cells(HSCs) and progenitor cells(PCs) were mobilized to peripheral blood by 8 subcutaneous injections of granulocyte colonystimulating factor(G-CSF) for 4 d and are harvested at day 5. The cells were administered to the main arm intrathecally every 3 mo for a long term(3-5 years) according to the internal research protocol international medical institute of tissue engineering. Magnetic resonance imaging of the site of injury and urodyna-mic tests were performed every 6 mo. Motor evoked potentials(MEP), somatosensory evoked potentials(SSEP) were evaluated every 3 mo. The patients were evaluated with american spianl injury association(ASIA) index, functional independence measure index, the Medical Research Council Scale, the International Standards for Neurological Classification of Spinal Cord Injury(ISCSCI-92) and specifically developed scales. The function of bladder was evaluated by a specifically developed clinical scale. The long-term clinical outcomes were assessed for the SCI patients who received no less than 20 intrathecal transplantations of HSCs and hematopoietic precursors(HPs).RESULTS: The restoration of neurologic deficit after HSCs and HPs transplantations was proved stable and evident in 57.4% of the cases. In 42.6% cases no neurologic improvement has been observed. In 50% of the cases the motor restoration began after the first transplantation, which is confirmed in average by 9.9 points improvement in neurologic impairment as compared to the baseline(P < 0.05). Repair of the urinary system was observed in 47.7% of the cases. The sensitivity improved from baseline 124.3 points to 138.4 after the first and to 153.5 points after the second transplantations of HSCs and HPs(P < 0.05, between the stages of research). The evaluation with ASIA index demonstrated regress of neurologic symptoms in 23 cases. Motor progress was also assessed with the ISCISCI-92 motor and sensory scores, and the data coincided with those received with the specifically developed scale. The number of the patients with the signs of locomotive repair was 56.9%. No life threatening complications or adverse effects have been observed.CONCLUSION: The method is safe, effective and considerably improves the life quality of SCI patients. The therapy is approved for clinical use as the treatment of choice.

Role of osteoclasts in regulating hematopoietic stem and progenitor cells

Bone marrow(BM) cavities are utilized for hematopoiesis and to maintain hematopoietic stem cells(HSCs). HSCs have the ability to self-renew as well as to differentiate into multiple different hematopoietic lineage cells. HSCs produce their daughter cells throughout the lifespan of individuals and thus, maintaining HSCs is crucial for individual life. BM cavities provide a specialized microenvironment termed "niche" to support HSCs. Niches are composed of various types of cells such as osteoblasts, endothelial cells and reticular cells. Osteoclasts are unique cells which resorb bones and are required for BM cavity formation. Loss of osteoclast function or differentiation results in inhibition of BM cavity formation, an osteopetrotic phenotype. Osteoclasts are also reportedly required for hematopoietic stem and progenitor cell(HSPC) mobilization to the periphery from BM cavities. Thus, lack of osteoclasts likely results in inhibition of HSC maintenance and HSPC mobilization. However, we found that osteoclasts are dispensable for hematopoietic stem cell maintenance and mobilization by using three independent osteoclast-less animal models. In this review, I will discuss the roles of osteoclasts in hematopoietic stem cell maintenance and mobilization.

The Impact of Blood Transfusion on the Efficiency of Stem Cell Transplants

Background: While blood product transfusion is essential for managing hematologic deficits in Allogenic Hematopoietic stem cell transplant (AHSCT) recipients, it has risks including infectious disease transmission, alloimmunization, and transfusion reactions. These risks have sparked an ongoing debate regarding the overall impact of transfusions on patient outcomes. Thus, this study aimed to evaluate the impact of Red Blood Cells (RBCs) and/or platelet transfusion on the infection incidence and overall survival in AHSCT patients. Methods: We performed a retrospective analysis of clinical and laboratory data of sixty adult patients with primary malignant hematological disorder who had undergone AHSCT. Participants’ data were categorized into two groups;Group 1 (low transfusion group) consisted of patients receiving 10 units. Quantitative data were expressed as mean ± SD. The t-test of significance and Chi-square (χ2) test were used, with p ≤ 0.05 considered significant. Result: A total of 60 patients’ data was included. In Group 1, out of 30 patients, 13 (43.33%) developed infections. In contrast, Group 2 had 21 (70%) out of 30 patients develop infections. Group 1 had a higher survival rate (57.8%) than Group 2 (transfusion > 10 units) (46.2%) with a chi-square value = 23.56, and p-value Conclusion: The volume of blood product transfusions has a considerable impact on patient outcomes, particularly infection and survival rates. Additional long-term prospective studies and larger randomized controlled trials are needed to strengthen the evidence for determining transfusion protocols for these patients.

Involvement of VLA-5 and VLA-6 in facilitating endothelium-oriented transmigration of hematopoietic stem/progenitor cells

目的 :研究 VLA- 5及 VLA- 6是否参与内皮细胞促进的造血干 /祖细胞定向移行。方法 :对纯化人 CD34+ 细胞进行体外移行及阻断实验 ,观察其穿移覆盖人脐静脉内皮细胞 ( HUVECs)滤膜的能力。应用四色荧光活化流式细胞术 ( FACS)检测 CD34+细胞其粘附分子及趋化因子受体CXCR- 4的表达谱。结果 :基质由来因子 ( SDF) - 1 α介导的动员外周血 ( m PB)及骨髓 ( BM)来源的CD34+ 细胞穿透覆盖 HUVECs滤膜百分率分别为 ( 5 6.6± 2 0 .1 ) %及 ( 1 5 .6± 1 .8) % ,显著高于其穿移未覆盖 HUVECs滤膜的比率。预先对 CD34+ 细胞进行抗 VLA- 5和 /或 VLA- 6中和抗体处理可消除这一促进效应。此外 ,BM来源的 CD34+细胞其穿移覆盖及未覆盖 HUVECs滤膜的能力均显著低于 m PB CD34+细胞 ,两者间穿移能力的差异与其 VLA- 5及 VLA- 6(而非 VLA- 4及趋化因子受体 CXCR- 4)抗原表达水平相关。结论 :VLA- 5和 VLA- 6参与 HUVECs促进 HS/PCs穿移能力。

Impact of T cells on hematopoietic stem and progenitor cell function:Good guys or bad guys?

When hematopoietic stem and progenitor cells(HSPC)are harvested for transplantation, either from the bone marrow or from mobilized blood, the graft contains a significant number of T cells. It is these T cells that are the major drivers of graft-vs-host disease(Gv HD). The risk for Gv HD can simply be reduced by the removal of these T cells from the graft. However, this is not always desirable, as this procedure also decreases the engraftment of the transplanted HSPCs and, if applicable, a graft-vs-tumor effect. This poses an important conundrum in the field: T cells act as a double-edged sword upon allogeneic HSPC transplantation, as they support engraftment of HSPCs and provide anti-tumor activity, but can also cause Gv HD. It has recently been suggested that T cells also enhance the engraftment of autologous HSPCs, thus supporting the notion that T cells and HSPCs have an important functional interaction that is highly beneficial, in particular during transplantation. The underlying reason on why and how T cells contribute to HSPC engraftment is still poorly understood. Therefore, we evaluate in this review the studies that have examined the role of T cells during HSPC transplantation and the possible mechanisms involved in their supporting function. Understanding the underlying cellular and molecular mechanisms can provide new insight into improving HSPC engraftment and thus lower the number of HSPCs required during transplantation. Moreover, it could provide new avenues to limit the development of severe Gv HD, thus making HSPC transplantations more efficient and ultimately safer.

Hematopoietic stem cells from peripheral blood the perspective of non-mobilized peripheral blood

The peripheral blood is a major source of hematopoietic stem cells. Almost for two decades the peripheral blood has been mobilized, in order to enhance the CD34+ concentration. The isolated stem cells from the mobilized peripheral blood are used as an alternative, or in addition to bone marrow derived stem cells. In this paper, a new perspective is being discussed;the use of non-mobilized peripheral blood as an alternative source for hematopoietic progenitor cells. The number of isolated hematopoietic stem cells is evaluated using flow cytometry. The viability can be evaluated using the trypan blue exclusion test, the flow cytometry or automated assays. The isolated hematopoietic stem cells could be used for ex vivo expansion either in static systems or in proper bioreactor systems, prior to cryopreservation and/or transplantation.

Establishment of a humanized mouse model using steady-state peripheral blood-derived hematopoietic stem and progenitor cells facilitates screening of cancer-targeted T-cell repertoires

Background:Cancer-targeted T-cell receptor T(TCR-T)cells hold promise in treating cancers such as hematological malignancies and breast cancers.However,approaches to obtain cancer-reactive TCR-T cells have been unsuccessful.Methods:Here,we developed a novel strategy to screen for cancer-targeted TCR-T cells using a special humanized mouse model with person-specific immune fingerprints.Rare steady-state circulating hematopoietic stem and progenitor cells were expanded via three-dimensional culture of steady-state peripheral blood mononuclear cells,and then the expanded cells were applied to establish humanized mice.The human immune system was evaluated according to the kinetics of dendritic cells,monocytes,T-cell subsets,and cytokines.To fully stimulate the immune response and to obtain B-cell precursor NAML-6-and triple-negative breast cancer MDA-MB-231-targeted TCR-T cells,we used the inactivated cells above to treat humanized mice twice a day every 7 days.Then,human T cells were processed for TCRβ-chain(TRB)sequencing analysis.After the repertoires had been constructed,features such as the fraction,diversity,and immune signature were investigated.Results:The results demonstrated an increase in diversity and clonality of T cells after treatment.The preferential usage and features of TRBV,TRBJ,and the V–J combination were also changed.The stress also induced highly clonal Science and Technology,Grant/Award Number:2021C03010;Zhejiang Provincial Natural Science Foundation of China,Grant/Award Numbers:LTGY24H080003,LY21H080004 expansion.Tumor burden and survival analysis demonstrated that stress induction could significantly inhibit the growth of subsequently transfused live tumor cells and prolong the survival of the humanized mice.Conclusions:We constructed a personalized humanized mouse model to screen cancer-targeted TCR-T pools.Our platform provides an effective source of cancer-targeted TCR-T cells and allows for the design of patient-specific engineered T cells.It therefore has the potential to greatly benefit cancer treatment.

Transplantation of mesenchymal stem cells from human umbilical cord versus human umbilical cord blood for peripheral nerve regeneration

BACKGROUND： Mesenchymal stem cells （MSCs） appear to be a good alternative to Schwann cells in the treatment of peripheral nerve injury. Fetal stem cells, like umbilical cord blood （UCB） and umbilical cord （UC） stem cells, have several advantages over adult stem cells. OBJECTIVE： To assess the effects of UC-derived MSCs （UCMSCs） and UCB-derived MSCs （UCBMSCs） in repair of sciatic nerve defects. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at the laboratory of Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from July to December 2009. MATERIALS： UCMSCs were provided by the Research Institute of Biotechnology, Dongguk University. UCBMSCs were provided by the Laboratory of Stem Cells and Tumor Biology, College of Veterinary Medicine, Seoul National University. Dulbecco＇s modified Eagle＇s medium （DMEM） was purchased from Gibco-BRL, USA. METHODS： Seven-week-old Sprague-Dawley rats were randomly and evenly divided into three groups： DMEM, UCBMSCs, and UCMSCs. A 10-mm defect in the left sciatic nerve was constructed in all rats. DMEM （15 μL） containing 1×10^6 UCBMSCs or UCMSCs was injected into the gap between nerve stumps, with the surrounding epineurium as a natural conduit. For the DMEM group, simple DMEM was injected. MAIN OUTCOME MEASURES： At 7 weeks after sciatic nerve dissection, dorsal root ganglia neurons were labeled by fluorogold retrograde labeling. At 8 weeks, electrophysiology and histomorphometry were performed. At 2, 4, 6, and 8 weeks after surgery, sciatic nerve function was evaluated using gait analysis. RESULTS： The UCBMSCs group and the UCMSCs group exhibited similar sciatic nerve function and electrophysiological indices, which were better than the DMEM group, as measured by gait analysis （P 〈 0.05）. Fluorogold retrograde labeling of sciatic nerve revealed that the UCBMSCs group demonstrated a higher number of labeled neurons; however, the differences were not significant. Histomorphometric indices were similar in the UCBMSCs and UCMSCs groups, and total axon counts, particularly axon density （P 〈 0.05）, were significantly greater in the UCBMSCs and UCMSCs groups than in the DMEM group. CONCLUSION： Transplanting either UCBMSCs or UCMSCs into axotomized sciatic nerves could accelerate and promote sciatic nerve regeneration over 8 weeks. Both treatments had similar effects on nerve regeneration.

Mesenchymal stem cells derived from human placenta suppress allogeneic umbilical cord blood lymphocyte proliferation

Human placenta-derived mononuclear cells （MNC） were isolated by a Percoll density gradient and cultured in mesenchymal stem cell （MSC） maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblastlike morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitro differentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic and chondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was a homogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105, CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and m-smooth muscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class Ⅰ major histocompatibility complex （MHC-I）, but they did not express MHC-Ⅱ molecules. Additionally these cells could suppress umbilical cord blood （UCB） lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. This strongly implies that they may have potential application in allograft transplantation. Since placenta and UCB are homogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells （HSC） from UCB to reduce the potential graft-versus-host disease （GVHD） in recipients.

Stem cell transplantation for treatment of cerebral ischemia in rats Effects of human umbilical cord blood stem cells and human neural stem cells

BACKGROUND： Exogenous neural stem cell transplantation promotes neural regeneration. However, various types of stem cells transplantation outcomes remain controversial. OBJECTIVE： To explore distribution, proliferation and differentiation of human neural stem cells （hNSCs） and human umbilical cord blood stem cells （hUCBSCs） following transplantation in ischemic brain tissue of rats, and to compare therapeutic outcomes between hNSCs and hUCBSCs. DESIGN, TIME AND SETTING： Randomized controlled animal studies were performed at the Experimental Animal Center of Nanjing Medical University and Central Laboratory of Second Affiliated Hospital of Nanjing Medical University of China from September 2008 to April 2009. MATERIALS： hNSCs were harvested from brain tissue of 10 13 week old fetuses following spontaneous abortion, and hUCBSCs were collected from umbilical cord blood of full-term newborns at the Second Affiliated Hospital of Nanjing Medical University of China. hNSCs and hUCBSCs were labeled by 5-bromodeoxyuridine （BrdU） prior to transplantation. METHODS： Rat models of cerebral ischemia were established by the suture method. A total of 60 healthy male Sprague Dawley rats aged 7-9 weeks were randomly assigned to hNSC transplantation, hUCBSC transplantation and control groups. The rat models in the hNSC transplantation, hUCBSC transplantation and control groups were infused with hNSC suspension, hUCBSC suspension and saline via the caudal vein, respectively. MAIN OUTCOME MEASURES： The distribution, proliferation and differentiation of hNSCs and hUCBSCs in ischemic brain tissue were observed using immunohistochemical methods. Neurological function in rats was assessed using the neurological severity score. RESULTS： The number of BrdU-positive cells was significantly greater in the hNSC transplantation group compared with hUCBSC transplantation group at 14 days following transplantation （P 〈 0.05） The number of BrdU-positive cells reached a peak at 28 days following transplantation. Nestin-positive, glial fibrillary acidic protein-positive, cyclic nucleotide 3＇ phosphohydrolase-positive and neuron specific enolase-positive cells were visible following transplantation. No significant difference was determined in the constituent ratio of various cells between hNSC and hUCBSC transplantation groups （P 〉 0.05）. The neurological severity score was significantly decreased in rats at 21 days following transplantation （P 〈 0.05）. No significant difference was detected in neurological severity score between hNSC and hUCBSC transplantation groups at various time points （P 〉 0.05）. CONCLUSION： The transplanted hNSCs and hUCBSCs can migrate into ischemic brain tissue, proliferate and differentiate into neuron-like, astrocyte-like and oligodendrocyte-like cells, and improve neurological function in rats with cerebral ischemia.

Differentiation of human umbilical cord blood stem cells into hepatocytes in vivo and in vitro

AIM： To study the condition and potentiality of human umbilical cord blood stem cells （HUCBSC） to differentiate into hepatocytes in vivo or in vitro. METHODS： In a cell culture study of human umbilical cord blood stem cell （HUCBSC） differentiation, human umbilical cord blood mononuclear cells （HUCBMNC） were separated by density gradient centrifugation. Fibroblast growth factor （FGF） and hepatocyte growth factor （HGF） and the supernatant of fetal liver were added in the inducing groups. Only FGF was added in the control group. The expansion and differentiation of HUCBMNC in each group were observed. Human alpha fetoprotein （AFP） and albumin （ALB） were detected by immunohistochemistry. In the animal experiments, the survival SD rats with acute hepatic injury after carbon tetrachloride （CCL4） injection 48 h were randomly divided into three groups. The rats in group A were treated with human umbilical cord blood serum. The rats in group B were treated with HUCBMNC transplantation. The rats in group C were treated with HUCBMNC transplantation followed by intraperitoneal cyclophosphamide for 7 d. The rats were killed at different time points after the treatment and the liver tissue was histopathologically studied and human AFP and ALB detected by immunohistochemistry. The human X inactive-specific transcript gene fragment in the liver tissue was amplified by PCR to find human DNA. RESULTS： The results of cell culture showed that adherent cells were stained negative for AFP or ALB in control group. However, the adherent cells in the inducing groups stained positive for AFP or ALB. The result of animal experiment showed that no human AFP or ALB positive cells present in the liver tissue of group A （control group）. However, many human AFP or ALB positive cells were scattered around sinus hepaUcus and the central veins of hepatic Iobules and in the portal area in group B and group C after one month. The fragment of human X chromagene could be detected in the liver tissue of groups B and C, but not in group A.CONCLUSION： Under certain conditions HUCBSC can differentiate into liver cells in vivo and in vitro.

Hematopoietic stem cells in research and clinical applications:The“CD34 issue”

In this paper,experimental findings concerning the kinetics of hematopoietic reconstitution are compared to corresponding clinical data.Although not clearly apparent,the transplantation practice seems to confirm the basic proposals of experimental hematology concerning hematopoietic reconstitution resulting from successive waves of repopulation stemming from different subpopulations of progenitor and stem cells.One of the "f irst rate" parameters in clinical transplantations in hematology;i.e.the CD34+ positive cell dose,has been discussed with respect to the functional heterogeneity and variability of cell populations endowed by expression of CD34.This parameter is useful only if the relative proportion of stem and progenitor cells in the CD34+ cell population is more or less maintained in a series of patients or donors.This proportion could vary with respect to the source,pathology,treatment,processing procedure,the graft ex vivo treatment and so on.Therefore,a universal dose of CD34+ cells cannot be def ined.In addition,to avoid further confusion,the CD34+ cells should not be named "stem cells" or "progenitor cells" since these denominations only concern functionally characterized cell entities.

Transplantation of human umbilical cord blood mesenchymal stem cells to treat a rat model of traumatic brain injury

In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated around the injury site, surviving up to 4 weeks post-transplantation. In addition, transplantation-related death did not occur, and neurological functions significantly improved. Histological detection revealed attenuated pathological injury in rat brain tissues following human umbilical cord blood mesenchymal stem cell transplantation. In addition, the number of apoptotic cells decreased. Immunohistochemistry and in situ hybridization showed increased expression of brain-derived neurotrophic factor, nerve growth factor, basic fibroblast growth factor, and vascular endothelial growth factor, along with increased microvessel density in surrounding areas of brain injury. Results demonstrated migration of transplanted human umbilical cord blood mesenchymal stem cells into the lesioned boundary zone of rats, as well as increased angiogenesis and expression of related neurotrophic factors in the lesioned boundary zone.

Differentiation and tumorigenicity of neural stem cells from human cord blood mesenchymal stem cells

BACKGROUND： Mesenchymal stem cells （MSCs） are capable of differentiating into a variety of tissues and exhibit low immunogenicity. OBJECTIVE： To investigate isolation and in vitro cultivation methods of human cord blood MSCs, to observe expression of neural stem cell （NSC） marker mRNA under induction, and to detect tumorigenicity in animals. DESIGN, TIME AND SETTING： A cell biological, in vitro trial and a randomized, controlled, in vivo experiment were performed at the Department of Neurology, Daping Hospital at the Third Military Medical University of Chinese PLA from August 2006 to May 2008. MATERIALS： Umbilical cord blood was collected from full-term-delivery fetus at the Department of Gynecology and Obstetrics of Daping Hospital, China. Eighteen BALB/C nu/nu nude mice were randomly assigned to three groups： back subcutaneous, cervical subcutaneous, and control, with 6 mice in each group. METHODS： Monocytes were isolated from heparinized human cord blood samples by density gradient centrifugation and then adherent cultivated in vitro to obtain MSC clones. After the cord blood MSCs were cultured for 7 days with nerve growth factor and retinoic acid to induce differentiation into NSCs, the cells （adjusted density of 1 × 10^7/mL） were prepared into cell suspension. In the back subcutaneous and cervical subcutaneous groups, nude mice were hypodermically injected with a 0.5-mL cell suspension into the back and cervical regions, respectively. In the control group, nude mice received a subcutaneous injection of 0.5 mL physiological saline into the back or cervical regions, respectively. MAIN OUTCOME MEASURES： Cellular morphology was observed by inverted microscopy, cultured cord blood MSCs were examined by flow cytometry, expression of nestin and musashi-1 mRNA was detected by reverse-transcriptase polymerase chain reaction prior to and after induction, and tumorigenicity following cord blood MSC transplantation was assayed by hematoxylin-eosin staining. RESULTS： Following adherent cultivation, the majority of cord blood monocytes became rhombic and strongly expressed CD29, but not CD34, CD1 la, or CD11 b. These results supported previously known characteristics of cord blood MSCs. Following differentiation induction, nestin and musashi-1 were expressed on the surface of NSCs, exhibiting strongest expression at 48 hours, and subsequently reducing expression. Cultured cord blood MSCs were not tumorigenic in the nude mice. Cellular morphology displayed no malignant changes between the control and subcutaneous groups. CONCLUSION： MSCs can be isolated from human cord blood, efficiently expanded under culture conditions, differentiated into NSCs following induction, and display no tumorigenicity in nude mice.

Induced Differentiation of Human Cord Blood Mesenchymal Stem/Pro genitor Cells into Cardiomyocyte-like Cells In Vitro

The feasibility of using cord blood mesenchymal stem/progenitor cells (CB-MSPCs) to regenerate cardiomyocytes and the optimal inducing conditions were investigated. The CB mononuclear cells were cultured in low serum DMEM medium to produce an adherent layer. After expansion, the adherent cells were added into cardiomyocyte inducing medium supplemented with 5-azacytidine. Cardiogenic specific contractile protein troponin T staining was performed to identify the cardiomy-ocyte-like cells. The results showed that the frequency of CB-MSPCs clones in CB mononuclear cells was 0. 5×10-6 and about 1. 3×107-fold expansion was achieved within 20 sub-cultivation. After car-diogenic induction, 70 % CB-MSPCs was differentiated into cardiomyocyte-like cells. It was indicated that low serum culture could expand CB-MSPCs extensively and the expanded CB-MSPCs could be induced to differentiate into cardiomyocyte-like cells in high efficiency.

Vein transplantation using human umbilical cord blood stem cells in the treatment of stroke sequela

BACKGROUND: Transplanted mononuclear cell (MNC) of umbilical blood can survive in central nervous system (CNS) of host through blood brain barrier, differentiate into nerve cells, migrate to damaged site and integrate morphological structure and function with nerve cells of host so as to improve deficiencies of sensatory function, motor function and cognitive function and influence on stroke sequela. OBJECTIVE: To observe the vein transplantation of human umbilical cord blood stem cells (HUCBSC) for improving neurological function, limb function and activity of daily living of patients with stroke and evaluate the reliability. DESIGN: Self-controlled study. SETTING: Department of Neurosurgery, the Second People's Hospital of Zhengzhou City; Red-crossed Blood Center of Henan Province; Department of Neurosurgery, the Fist Affiliated Hospital of Zhengzhou University. PARTICIPANTS: A total of 10 patients with stroke sequela were selected from Department of Cerebral Surgery, the Second People's Hospital of Zhengzhou City from April to December 2005. There were 9 males and 1 female aged from 35 to 75 years with the mean age of 56 years. All of them were diagnosed with CT and MRI examination and coincidence with diagnostic criteria of stroke established by the Fourth National Academic Meeting for Cerebrovascular Disease. All patients provided informed consent. METHODS: 80-140 mL umbilical blood of term birth of newborn was selected hermetically and maintained in sterile plastic bag. And then, the blood was centrifugated at the speed of 1 500 r/min for 30 minutes at 22 ℃ in order to separate MNC, i.e., HUCBSC. In addition, after final diagnosis during hospitalization, stroke patients were perfused with HUCBSC through superficial vein of back of the hand. Each patient was averagely perfused with 6 portions of HUCBSC (cellular numbers ≥ 1×108/portion) and the interval between each portion was 1-7 days with the mean interval of 4 days. MAIN OUTCOME MEASURES: ① Neurological function of stroke patients was evaluated with neurological function deficiency (NFD) before treatment and at 3 months after treatment. The scale includes consciousness, level fix function, facial paralysis, language, muscle force of upper limbs, muscle force of lower limb and step function. The total scores ranged from 0 to 45; meanwhile, the lower the scores were, the better the neurological function was. ② Motor function of injured limbs was evaluated with Fugl-Meyer Assessment (FMA), including motor function of upper limbs, motor function of lower limbs, balance ability, sensory function and motion of joint. The total scores ranged from 0 to 226; meanwhile, the higher the scores were, the better the motor function of limbs was. ③ Activities of daily living (ADL) was evaluated with Barthel Index (BI), including having meals, taking a bath, dressing oneself, putting on clothes, walking in balance and stair activity. The total scores ranged from 0 to 100; meanwhile, the higher the scores were, the stronger the ADL was. RESULTS: A total of 10 patients were involved in the final analysis. After treatment, NFD of stroke patients was (10.9±5.09) points, which was lower than that before treatment [(25.4±6.09) points, t =8.213, P < 0.01]. In addition, after treatment, FMA and BI of stroke patients were (80.9±25.00) points and (81.1±15.93) points, respectively, which were higher than those before treatment [(31.9±21.85) points, (36.2±19.41) points, t =13.024, 13.670, P < 0.01]. Immuno-suppressive drugs were not used during the whole therapeutic procedure; moreover, immunological rejection and allergic reaction were not observed during the same period. CONCLUSION: Transplanting HUCBSC through superficial vein of back of the hand is regarded as a simple and safe method for the treatment of stroke sequela.

Prospects for the therapeutic development of umbilical cord bloodderived mesenchymal stem cells

Umbilical cord blood(UCB)is a primitive and abundant source of mesenchymal stem cells(MSCs).UCB-derived MSCs have a broad and efficient therapeutic capacity to treat various diseases and disorders.Despite the high latent selfrenewal and differentiation capacity of these cells,the safety,efficacy,and yield of MSCs expanded for ex vivo clinical applications remains a concern.However,immunomodulatory effects have emerged in various disease models,exhibiting specific mechanisms of action,such as cell migration and homing,angiogenesis,anti-apoptosis,proliferation,anti-cancer,anti-fibrosis,anti-inflammation and tissue regeneration.Herein,we review the current literature pertaining to the UCB-derived MSC application as potential treatment strategies,and discuss the concerns regarding the safety and mass production issues in future applications.