Genetically modified human umbilical cord blood cells as a promising strategy for treatment of spinal cord injury

Spinal cord injury （SCI） continues to be a pressing health and social problem. The injury leads to neuronal and glial cell death accompanied by degeneration of nerve fibers. There are currently no particularly effective treatments. SCI causes profound disabil- ity of people affected and has attracted increased attention in the international field of neuroregeneration. For the past two decades, much hope has been placed in cell therapies for the restoration of both structure and function of the injured spinal cord. Embryonic and neural stem cells, olfactory ensheathing cells, microglia-like cells, Schwann cells, mesenchymal stem cells.

Transplantation of microencapsulated umbilical-cord-blood-derived hepatic-like cells for treatment of hepatic failure

AIM: To investigate intraperitoneal transplantation of microencapsulated hepatic-like cells from human umbilical cord blood for treatment of hepatic failure in rats. METHODS: CD34+ cells in umbilical cord blood cells were isolated by magnetic cell sorting. In the in vitro experiment, sorted CD34+ cells were amplified and induced into hepatic-like cells by culturing with a combination of fibroblast growth factor 4 and hepatocyte growth factor. Cultures without growth factor addition served as controls. mRNA and protein levels for hepatic-like cells were analyzed by reverse transcription-polymerase chain reaction, immunohistochemistry and immunofluorescence. In the in vivo experiment, the hepatic-like cells were encapsulated and transplanted into the abdominal cavity of acute hepatic failure (AHF) rats at 48 h after D-galactosamine induction of acute hepatic failure. Transplantation with PBS and unencapsulated hepatic-like cells served as controls. The mortality rate, hepatic pathological changes and serum biochemical indexes were determined. The morphology and structure of microcapsules in the greater omentum were observed. RESULTS: Human albumin, alpha-fetoprotein and GATA-4 mRNA and albumin protein positive cells were found among cultured cells after 16 d. Albumin level in culture medium was significantly increased after culturing with growth factors in comparison with culturing without growth factor addition (P < 0.01). Compared with the unencapsulated group, the mortality rate of the encapsulated hepatic-like cell-transplanted group was significantly lower (P < 0.05). Serum biochemical parameters, alanine aminotransferase, aspartate aminotransferase and total bilirubin in the encapsulated group were significantly improvement compared with the PBS control group (P < 0.01). Pathological staining further supported these findings. At 1-2 wk post-transplantation, free microcapsules with a round clear structure and a smooth surface were observed in peritoneal lavage fluid, surviving cells inside microcapsules were found by trypan blue staining, but some fibrous tissue around microcapsules was also detected in the greater omentum of encapsulated group by hematoxylin and eosin staining. CONCLUSION: Transplantation of microencapsulated hepatic-like cells derived from umbilical cord blood cells could preliminarily alleviate the symptoms of AHF rats.

Optimal time for human umbilical cord blood cell transplantation in rats with myocardial infarction

Background Cell therapy for cardiac regeneration is still under investigation. To date there have been a limited number of studies describing the optimal time for cell injection. The present study aimed to examine the optimal time for human umbilical cord blood cells （HUCBCs） transplantation after myocardial infarction （MI）. Methods The animals underwent MI by ligation of the left anterior descending coronary artery and received an intravenous injection of equal volumes of HUCBCs or phosphate buffered saline at days 1, 5, 10 and 30 after MI. HUCBCs were detected by immunostaining against human human leucocyte antigen （HLA）. Cardiac function, histological analysis and measurement of vascular endothelial growth factor （VEGF） were performed 4 weeks after cell transplantation. Results HUCBCs transplantation could improve cardiac function in rats that received transplantation at 5 and 10 days after MI. The best benefit was achieved in rats that received cells at 10-day after MI. Survival of engrafted HUCBCs, angiogenesis and VEGF expression were more obvious in the 10-day transplantation group than in the other transplantation groups. No evidence of cardiomyocyte regeneration was detected in any transplanted rats. Conclusions HUCBCs transplantation could improve cardiac function in rats that received HUCBCs at days 5 and 10 after MI with the optimal time for transplantation being 10 days post MI. Angiogenesis, but not cardiomyocyte regeneration, played a key role in the cardiac function improvement.

Human umbilical cord blood stem cell transplantation for the treatment of chronic spinal cord injury Electrophysiological changes and long-term efficacy

Stem cell transplantation can promote functional restoration following acute spinal cord injury （injury time 〈 3 months）, but the safety and long-term efficacy of this treatment need further exploration. In this study, 25 patients with traumatic spinal cord injury （injury time 〉 6 months） were treated with human umbilical cord blood stem cells via intravenous and intrathecal injection. The follow-up period was 12 months after transplantation. Results found that autonomic nerve functions were restored and the latent period of somatosensory evoked potentials was reduced. There were no severe adverse reactions in patients following stem cell transplantation. These experimental findings suggest that the transplantation of human umbilical cord blood stem cells is a safe and effective treatment for patients with traumatic spinal cord injury

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.

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.

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.

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.

Umbilical cord blood stem cell treatment for a patient with psoriatic arthritis

Clinical and laboratory results document psoriatic arthritis in a 56-year old patient. The symptoms did not resolve with standard treatments(nonsteroidal anti-inflammatory drugs, steroids and methotrexate). TNF-alpha inhibitors(certolizumab pegol and adalimumab) were added to the treatment regime, with some adverse effects. A trial of human umbilical cord stem cell therapy was then initiated. The stem cells were enriched and concentrated from whole cord blood, by removal of erythrocytes and centrifugation. The patient received several infusions of cord blood stem cells, through intravenous and intra-articular injections. These stem cell treatments correlated with remission of symptoms(joint pain and psoriatic plaques) and normalized serologic results for the inflammatory markers C-reactive protein and erythrocyte sedimentation rate. These improvements were noted within the first thirty days post-treatment, and were sustained for more than one year. The results of this trial suggest that cord blood stem cells may have important therapeutic value for patients with psoriatic arthritis, particularly for those who cannot tolerate standard treatments.

Human umbilical cord blood stem cells and brainderived neurotrophic factor for optic nerve injury: a biomechanical evaluation

Treatment for optic nerve injury by brain-derived neurotrophic factor or the transplantation of human umbilical cord blood stem cells has gained progress, but analysis by biomechanical indicators is rare. Rabbit models of optic nerve injury were established by a clamp. At 7 days after injury, the vitreous body received a one-time injection of 50 μg brain-derived neurotrophic factor or 1 × 10^6 human umbilical cord blood stem cells. After 30 days, the maximum load, maximum stress, maximum strain, elastic limit load, elastic limit stress, and elastic limit strain had clearly improved in rabbit models of optical nerve injury after treatment with brain-derived neurotrophic factor or human umbilical cord blood stem cells. The damage to the ultrastructure of the optic nerve had also been reduced. These findings suggest that human umbilical cord blood stem cells and brain-derived neurotrophic factor effectively repair the injured optical nerve, improve biomechanical properties, and contribute to the recovery after injury.

Lethal effect of mononuclear cells derived from human umbilical cord blood differentiating into dendritic cells after in vitro induction of cytokines on neuroblastoma cells

BACKGROUND： Dendritic cell is the most major antigen presenting cell of organism. It is proved in recent studies that human umbilical cord blood mononuclear cells induced and cultured in vitro by recombinant human granulocyte-macrophage colony stimulating factor （rhG-MCSF） and recombinant human interleukin-4 （rhlL-4） can generate a great many dendritic cells and promote the lethal effect of T cells on human neuroblastoma, but it is unclear that whether the lethal effect is associated with the most proper concentration of dendritic cells. OBJEETIVE： To investigate the lethal effect of human umbilical cord blood mononuclear cells induced in vitro by cytokines differentiating into dendritic cells on human neuroblastoma, and its best concentration range. DESIGN ： Open experiment SEI-FING： Department of Pediatrics, the Medical School Hospital of Qingdao University MATERIALS ： The study was carried out in the Shandong Provincial Key Laboratory （Laboratory for the Department of Pediatrics of the Medical School Hospital of Qingdao University） during September 2005 to May 2006. Human umbilical cord blood samples were taken from the healthy newborn infants of full-term normal delivery during October to November 2005 in the Medical School Hospital of Qingdao University, and were voluntarily donated by the puerperas. Main instruments： type 3111 CO2 incubator （Forma Scientific, USA）, type 550 ELISA Reader （Bio-Rad, USA）. Main reagents： neuroblastoma cell line SK-N-SH （Shanghai Institute of Life Science, Chinese Academy of Sciences）, RPMI-1640 culture fluid and fetal bovine serum （Hyclone）, rhlL-4 （Promega, USA）, rhG-MCSF （Harbin Pharmaceutic Group Bioengineering Co.Ltd）, rat anti-human CDla monoclonal antibody and FITC-labeled rabbit anti-rat IgG （Xiehe Stem cell Gene Engineering Co.Ltd）. METHODS： ① Human umbilical cord blood mononuclear cells obtained with attachment methods differentiated into human umbilical cord blood dendritic cells, presenting typical morphology of dendritic cells after in vitro induction by rhG-MCSF and rhlL-4. ② Different concentrations of dendritic cells[ dendritic cells： neuroblastoma cells=20：1,50：1,100：1 （2×10^8 L^-1,5×10^8 L^-1,1×10^9 L^-1）], 1×10^9 L^-1 T cells and 1×10^7 L^-1 neuroblastoma cells were added in the experimental group. 1 ×10^9 L^-1 T cells and 1 ×10^7 L^-1 neuroblastoma cells were added in the control group. ③ Main surface marker CDla molecules of dendritic cells were detected with indirect immunofluorescence, and the percent rate of dendritic cells was counted with ultraviolet light and expressed as the expression rate of CD1a^＋ cells. ④Single effector cells and target cells were respectively set in the experimental group and control group to obtain the lethal effect. The lethal effect of dendritic cells on neuroblastoma cells was indirectly evaluated by detecting cellular survival with MTT assay. The lethal effect（%）= （1-A experimentat well-A effector cell /A target cell well）×100%.⑤The expenmental data were presented as Mean ±SD, and paired t test was used. MAIN OUTCOME MEASURES： ① Morphological characters of dendritic cells in the process of induction and differentiation. ②CD1a^＋ cellular expression rate. ③Lethal effect of dendntic cells on neuroblastoma cells. RESULTS： ①Morphological characters of dendritic cells in the process of induction and differentiation： On the 15^th day after human umbilical cord blood mononuclear cells were induced by rhG-MCSF and rhlL-4, typical morphology of dendritic cells could be seen under an inverted microscope. ②Expression rate of CD1a^＋ cells was （43.12±5.83）%. ③Lethal effect of dendritic cells on neuroblastoma cells： Lethal effect of dendritic cells stimulated T cells in each experimental group （ dendritic cells： neuroblastoma cells=100：1,50：1, 20：1 respectively） on neuroblastoma cells was significantly higher than that in control group[（31.00 ±4.41 ）%, （30.92±5.27）%,（33.57±5.35）%,（26.23±5.20）%, t=3.51,2.98,4.24, P〈 0.01 ）; But the lethal effect of dendntic cells on neuroblastoma was significantly lower when their ratio was 100：1 and 50：1 in comparison with 20：1 （t=2.01,2.36, P 〈 0.05）, and no significant difference in lethal effect existed between the ratio at 100：1 and 50：1 （t=0.06,P 〉 0.05）. CONCLUSION： Dendritic cells differentiated from human umbilical cord blood mononuclear cells after in vitro induction of cytokines can promote the lethal effect of T cells on neuroblastoma cells. The lethal effect is associated with the concentration of dendritic cells within some range.

Editor's Choice——Umbilical cord blood mesenchymal stem cell differentiation and transplantation in neural regeneration

Previous in vivo experiments have shown that human umbilical cord blood mesenchymal stem cells can promote the proliferation and differentiation of damaged celts, and help to repair damaged sites, Recent studies have reported that umbilical cord blood-derived mesenchymal stem cells can differentiate into neurons and glial cells. Recent studies have reported that the repair mechanisms underlying cord blood stern cells involve the replacement of damaged cells and mediation of the local micro-environment.

Combined use of Y-tube conduits with human umbilical cord stem cells for repairing nerve bifurcation defects

Given the anatomic complexity at the bifurcation point of a nerve trunk,enforced suturing between stumps can lead to misdirection of nerve axons,thereby resulting in adverse consequences.We assumed that Y-tube conduits injected with human umbilical cord stem cells could be an effective method to solve such problems,but studies focused on the best type of Y-tube conduit remain controversial.Therefore,the present study evaluated the applicability and efficacy of various types of Y-tube conduits containing human umbilical cord stem cells for treating rat femoral nerve defects on their bifurcation points.At 12 weeks after the bridging surgery that included treatment with different types of Y-tube conduits,there were no differences in quadriceps femoris muscle weight or femoral nerve ultrastructure.However,the Y-tube conduit group with longer branches and a short trunk resulted in a better outcome according to retrograde labeling and electrophysiological analysis.It can be concluded from the study that repairing a mixed nerve defect at its bifurcation point with Y-tube conduits,in particular those with long branches and a short trunk,is effective and results in good outcomes.

Stem cell transplantation for spinal cord injury： a meta-analysis of treatment effectiveness and safety

OBJECTIVE： The aim of this study was to evaluate the effectiveness and safety of stem cell transplantation for spinal cord injury（SCI）.DATA SOURCES： PubM ed, EMBASE, Cochrane, China National Knowledge Infrastructure, China Science and Technology Journal, Wanfang, and Sino Med databases were systematically searched by computer to select clinical randomized controlled trials using stem cell transplantation to treat SCI, published between each database initiation and July 2016. DATA SELECTION： Randomized controlled trials comparing stem cell transplantation with rehabilitation treatment for patients with SCI. Inclusion criteria：（1） Patients with SCI diagnosed according to the American Spinal Injury Association（ASIA） International standards for neurological classification of SCI;（2） patients with SCI who received only stem cell transplantation therapy or stem cell transplantation combined with rehabilitation therapy;（3） one or more of the following outcomes reported： outcomes concerning neurological function including sensory function and locomotor function, activities of daily living, urination functions, and severity of SCI or adverse effects. Studies comprising patients with complications, without full-text, and preclinical animal models were excluded. Quality of the included studies was evaluated using the Cochrane risk of bias assessment tool and Rev Man V5.3 software, provided by the Cochrane Collaboration, was used to perform statistical analysis. OUTCOME MEASURES： ASIA motor score, ASIA light touch score, ASIA pinprick score, ASIA impairment scale grading improvement rate, activities of daily living score, residual urine volume, and adverse events.RESULTS： Ten studies comprising 377 patients were included in the analysis and the overall risk of bias was relatively low level. Four studies did not detail how random sequences were generated, two studies did not clearly state the blinding outcome assessment, two studies lacked blinding outcome assessment, one study lacked follow-up information, and four studies carried out selective reporting. Compared with rehabilitation therapy, stem cell transplantation significantly increased the lower limb light touch score（odds ratio（OR） = 3.43, 95% confidence interval（CI）： 0.01 – 6.86, P = 0.05）, lower limb pinprick score（OR = 3.93, 95%CI： 0.74 – 7.12, P = 0.02）, ASI grading rate（relative risk（RR） = 2.95, 95%CI： 1.64 – 5.29, P = 0.0003）, and notably reduced residual urine volume（OR = –8.10, 95%CI： –15.09 to –1.10, P = 0.02）. However, stem cell transplantation did not significantly improve motor score（OR = 1.89, 95%CI： –0.25 to 4.03, P = 0.08） or activities of daily living score（OR = 1.12, 95%CI： –1.17 to 4.04, P = 0.45）. Furthermore, stem cell transplantation caused a high rate of mild adverse effects（RR = 14.49, 95%CI： 5.34 – 34.08, P 〈 0.00001）; however, these were alleviated in a short time. CONCLUSION： Stem cell transplantation was determined to be an efficient and safe treatment for SCI and simultaneously improved sensory and bladder functions. Although associated minor and temporary adverse effects were observed with transplanted stem cells, spinal cord repair and axon remyelination were apparent. More randomized controlled trials with larger sample sizes and longer follow-up times are needed to further validate the effectiveness of stem cell transplantation in the treatment of SCI.

Transplanted human umbilical cord blood mononuclear cells improve left ventricular function through angiogenesis in myocardial infarction

Background Human umbilical cord blood contains an abundance of immature stem/progenitor cells, which may participate in the repair of hearts that have been damaged by myocardial infarction （MI）. This study aimed to evaluate the effects of human umbilical cord blood mononuclear cells （hUCBC） transplantation on cardiac function and left ventricular remodeling in rat model of MI. Methods Forty-five male Wistar rats were randomized into three groups： MI or control group （n=15）, MI plus cell transplantation （n=15）, and sham group （n=15）. Acute myocardial infarction （AMI） was established by ligating the left anterior descending artery, thereafter, hUCBC were implanted into the marginal area of infarcted myocardium. In MI/control group, DMEM was injected instead of hUCBC following the same protocol. Left ventricular function assessment was carded out by echocardiography and invasive hemodynamic measurements one month post MI. All rats were sacrificed for histological and immunochemical examinations.Results The transplanted hUCBC survived and engaged in the process of myocardial repair in the host heart. Echocardiography demonstrated that left ventricular function improved significantly in the rats that underwent cell transplantation. Hemodynamic studies found a significantly decreased left ventricular end-diastolic pressure （LVEDP） [（21.08±8.10） mmHg vs （30.82±9.59） mmHg, P〈0.05], increase in ＋dp/dtmax [（4.29± 1.27） mmHg/ms vs （3.24±0.75） mmHg/ms, P〈0.05）, and increase in -dp/dtmax [（3.71 ±0.79） mmHg/ms vs （3.00± 0.49） mmHg/ms, P〈0.05] among MI group with hUCBC transplantation when compared with MI/control group. Masson＇s trichrome staining revealed that the collagen density in the left ventricle was significantly lower in rats of transplantation group than that in the MI control groups [（6.33±2.69）% vs （11.10±3.75）%, P〈 0.01]. Based on immunostaining of α-actin, the numbers of microvessels were significantly （P〈0.01） increased at the boundary of infarction site. Similarly higher mRNA expression of vascular endothelial growth factor （VEGF） 164 and VEGF188 were found at 7- and 28-day post cell transplantation in MI group with hUCBC transplantation when compared with MI/control group. Conclusions Transplanted hUCBC can survive in host myocardium without immunorejection, significantly improve left ventricular remodeling after AMI and promote a higher level of angiogenesis in the infarct zones. All these factors beneficially affect cardiac repair in the setting of MI. Therefore human umbilical cord blood may be potential source for cell-based therapy for AMI.

Future perspectives on cell therapy for autism spectrum disorder

Autism spectrum disorder(ASD)is a complex neurodevelopmental condition characterized by impairments in social communication,abnormal to absent verbal communication,the presence of repetitive stereotypic verbal and nonverbal behaviors and restricted interests,with onset early in life.We showed cognitive and behavioral characteristics of ASD by impairment of communication,cognition,perception,motor skills,executive function,theory of mind and emotion control.Recently,pathogenesis of immune pathology in the brains of individuals with ASD has been focused.New therapeutic approaches in the viewpoints of immune modulation and microglial function are logical for novel treatments for individuals with ASD.Cell therapies such as umbilical cord blood cells and mesenchymal stromal cells for ASD will be a challenging and encouraging field in the future clinical study with progress of biotechnological science.

Functionality of a bicistronic construction containing HEXA and HEXB genes encoding β-hexosaminidase A for cell-mediated therapy of GM2 gangliosidoses

Tay-Sachs disease and Sandhoff disease are severe hereditary neurodegenerative disorders caused by a deficiency ofβ-hexosaminidase A(HexA)enzyme,which results in the accumulation of GM2 gangliosides in the nervous system cells.In this work,we analyzed the efficacy and safety of cell-mediated gene therapy for Sandhoff disease and Sandhoff disease using a bicistronic lentiviral vector encoding cDNA of HexAα-andβ-subunit genes separated by the nucleotide sequence of a P2A peptide(HEXA-HEXB).The functionality of the bicistronic construct containing the HEXA-HEXB genetic cassette was analyzed in a culture of HEK293T cells and human umbilical cord blood mononuclear cells(hUCBMCs).Our results showed that the enzymatic activity of HexA in the conditioned medium harvested from genetically modified HEK293T-HEXA-HEXB and hUCBMCs-HEXA-HEXB was increased by 23 and 8 times,respectively,compared with the conditioned medium of native cells.Western blot analysis showed that hUCBMCs-HEXA-HEXB secreted both completely separated HEXA and HEXB proteins,and an uncleaved protein containing HEXA+HEXB linked by the P2A peptide.Intravenous injection of genetically modified hUCBMCs-HEXA-HEXB to laboratory Wistar rats was carried out,and the HexA enzymatic activity in the blood plasma of experimental animals,as well as the number of live cells of immune system organs(spleen,thymus,bone marrow,lymph nodes)were determined.A significant increase in the enzymatic activity of HexA in the blood plasma of laboratory rats on days 6 and 9(by 2.5 and 3 times,respectively)after the administration of hUCBMCsHEXA-HEXB was shown.At the same time,the number of live cells in the studied organs remained unchanged.Thus,the functionality of the bicistronic genetic construct encoding cDNA of the HEXA and HEXB genes separated by the nucleotide sequence of the P2A peptide was shown in vitro and in vivo.We hypothesize that due to the natural ability of hUCBMCs to overcome biological barriers,such a strategy can restore the activity of the missing enzyme in the central nervous system of patients with GM2 gangliosidoses.Based on the obtained data,it can be concluded that intravenous administration of hUCBMCs with HexA overexpression is a promising method of the therapy for GM2 gangliosidoses.The animal protocol was approved by the Animal Ethics Committee of the Kazan Federal University(No.23)on June 30,2020.

Combination of epidural electrical stimulation with ex vivo triple gene therapy for spinal cord injury:a proof of principle study

Despite emerging contemporary biotechnological methods such as gene-and stem cell-based therapy,there are no clinically established therapeutic strategies for neural regeneration after spinal cord injury.Our previous studies have demonstrated that transplantation of genetically engineered human umbilical cord blood mononuclear cells producing three recombinant therapeutic molecules,including vascular endothelial growth factor(VEGF),glial cell-line derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)can improve morpho-functional recovery of injured spinal cord in rats and mini-pigs.To investigate the efficacy of human umbilical cord blood mononuclear cells-mediated triple-gene therapy combined with epidural electrical stimulation in the treatment of spinal cord injury,in this study,rats with moderate spinal cord contusion injury were intrathecally infused with human umbilical cord blood mononuclear cells expressing recombinant genes VEGF165,GDNF,NCAM1 at 4 hours after spinal cord injury.Three days after injury,epidural stimulations were given simultaneously above the lesion site at C5(to stimulate the cervical network related to forelimb functions)and below the lesion site at L2(to activate the central pattern generators)every other day for 4 weeks.Rats subjected to the combined treatment showed a limited functional improvement of the knee joint,high preservation of muscle fiber area in tibialis anterior muscle and increased H/M ratio in gastrocnemius muscle 30 days after spinal cord injury.However,beneficial cellular outcomes such as reduced apoptosis and increased sparing of the gray and white matters,and enhanced expression of heat shock and synaptic proteins were found in rats with spinal cord injury subjected to the combined epidural electrical stimulation with gene therapy.This study presents the first proof of principle study of combination of the multisite epidural electrical stimulation with ex vivo triple gene therapy(VEGF,GDNF and NCAM)for treatment of spinal cord injury in rat models.The animal protocols were approved by the Kazan State Medical University Animal Care and Use Committee(approval No.2.20.02.18)on February 20,2018.

Stem cell transplantation for treating stroke:status,trends and development

The developing approaches of thrombolytic therapy, endovascular treatment, neuroprotective therapy, and stem cell therapy have enabled breakthroughs in stroke treatment. In this study, we summarize and analyze trends and progress in stem cell transplantation for stroke treatment by retrieval of literature from Thomson Reuters Web of Science database, the NIH Clinical Trial Planning Grant Program, and Clinical Trials Registration Center in North America. In the last 10 years, there has been an increasing number of published articles on stem cell transplantation for stroke treatment. In particular, research from the USA and China has focused on stem cell transplantation. A total of 2,167 articles addressing stem cell transplantation for stroke treatment from 2004 to 2013 were retrieved from the Thomson Reuters Web of Science database. The ma- jority of these articles were from the USA （854, 39.4%）, with the journal Stroke publishing the most articles （145, 6.7%）. Of the published articles, 143 were funded by the National Institutes of Health （accounting for 6.6% of total publications）, and 91 by the National Natural Science Foundation of China. Between 2013 and 2014, the National Institutes of Health provided finan- cial support （$130 million subsidy） for 329 research projects on stroke therapy using stem cell transplantation. In 2014, 215 new projects were approved, receiving grants of up to $70,440,000. Ninety clinical trials focusing on stem cell transplantation for stroke were registered in the Clinical Trial Registration Center in North America, with 40 trials registered in the USA （ranked first place）. China had the maximum number of registered research or clinical trials （10 projects）.