Umbilical Cord Blood-derived Mononuclear Cells Research Articles

Comparative Study of the Two High-Efficient Strategies for in vitro Generation of Human Umbilical Cord Blood-derived Natural Killer Cells

To explore the similarities and variations of biological phenotype and cytotoxicity of human umbilical cord blood natural killer cells (hUC- NK) after human umbilical cord blood-derived mononuclear cells (hUC-MNC) activated and expanded by two in vitro high-efficient strategies. Umbilical cord blood mononuclear cells (MNC) from healthy donor were enriched by Ficoll-based density gradient centrifugation. Then, the phenotype, subpopulations, cell viability and cytotoxicity of NK cells derived from Miltenyi medium (denoted as M-NK) and X-VIVO 15 (denoted as X-NK) were compared using a "3IL" strategy. After a 14-day's culture, the contents of CD3-CD56+ NK cells were elevated from 4.25%±0.04% (d 0) to 71%±0.18% (M-NK) and 75.2%±1.1% (X-NK) respectively. Compared with X-NK group, the proportion of CD3+CD4+ T cells and CD3+CD56+ NKT cells in M-NK group decreased significantly. The percentages of CD16+, NKG2D+, NKp44+, CD25+ NK cells in X-NK group was higher than those in the M-NK group, while the total number of expanded NK cells in X-NK group was half of that in M-NK group. There were no significant differences between X-NK and M-NK groups in cell proliferation and cell cycle, except for the lower percentage of Annexin V+ apoptotic cells in M-NK group. Compared with X-NK group, the proportion of CD107a+ NK cells in M-NK group were higher under the same effector-target ratio (E∶T) (P<0.05). The two strategies were adequate for high-efficient generation of NK cells with high level of activation in vitro, however, there are differences in biological phenotypes and tumor cytotoxicity.

Autologous Umbilical Cord Blood–Derived Mononuclear Cell Therapy Promotes Cardiac Proliferation and Adaptation in a Porcine Model of Right Ventricle Pressure Overload

Congenital heart diseases, including single ventricle circulations, are clinically challenging due to chronic pressure overload and the inability of the myocardium to compensate for lifelong physiological demands. To determine the clinical relevance of autologous umbilical cord blood–derived mononuclear cells (UCB-MNCs) as a therapy to augment cardiac adaptation following surgical management of congenital heart disease, a validated model system of right ventricular pressure overload due to pulmonary artery banding (PAB) in juvenile pigs has been employed. PAB in a juvenile porcine model and intramyocardial delivery of UCB-MNCs was evaluated in three distinct 12-week studies utilizing serial cardiac imaging and end-of-study pathology evaluations. PAB reproducibly induced pressure overload leading to chronic right ventricular remodeling including significant myocardial fibrosis and elevation of heart failure biomarkers. High-dose UCB-MNCs (3 million/kg) delivered into the right ventricular myocardium did not cause any detectable safety issues in the context of arrhythmias or abnormal cardiac physiology. In addition, this high-dose treatment compared with placebo controls demonstrated that UCB-MNCs promoted a significant increase in Ki-67-positive cardiomyocytes coupled with an increase in the number of CD31+ endothelium. Furthermore, the incorporation of BrdU-labeled cells within the myocardium confirmed the biological potency of the high-dose UCB-MNC treatment. Finally, the cell-based treatment augmented the physiological adaptation compared with controls with a trend toward increased right ventricular mass within the 12 weeks of the follow-up period. Despite these adaptations, functional changes as measured by echocardiography and magnetic resonance imaging did not demonstrate differences between cohorts in this surgical model system. Therefore, this randomized, double-blinded, placebo-controlled pre-clinical trial establishes the safety of UCB-MNCs delivered via intramyocardial injections in a dysfunctional right ventricle and validates the induction of cardiac proliferation and angiogenesis as transient paracrine mechanisms that may be important to optimize long-term outcomes for surgically repaired congenital heart diseases.

Clinical Impact of Autologous Cell Therapy on Hypoplastic Left Heart Syndrome After Bidirectional Cavopulmonary Anastomosis

Preservation of right ventricle function (RV) is a key to favorable outcome in Hypoplastic Left Heart Syndrome (HLHS), but methods to preserve or improve RV function are limited. Our goal was to assess the clinical and functional impact of autologous umbilical cord blood-derived mononuclear cells (UCB-MNC) therapy when given to patients with HLHS at Stage II surgery. UCB-MNC patients were enrolled prospectively in a phase I, FDA monitored trial as previously described (Burkhart etal., 2019). Matched retrospective controls were identified by review of clinical databases. Growth and RV echocardiographic variables were assessed in both groups prestage II through the first 6 months postoperatively. Statistical comparisons between the groups at similar postoperative time points were made to define potential impact of the cell therapy. There were 7 UCB-MNC patients and 17 controls. Prestage II, most parameters showed no differences between groups, although median fractional area change (FAC) was slightly greater in the controls (FAC: controls = 45% vs UCB-MNC = 41% P= 0.02). At dismissal, FAC and estimated Ejection Fraction (EF) decreased in controls, while both were unchanged from baseline in UCB-MNC patients (ΔFAC: -5% vs -1%, P < 0.01; ΔEF: -8% vs 0%, P = 0.03, respectively). Subsequently, median FAC increased slightly in UCB-MNC patients over the 6 month follow-up period, while it decreased in controls (ΔFAC: UCB-MNC +3% vs control -5%, P = 0.03). Preoperative weight percentiles were similar in both groups (UCB-MNC 34%ile vs controls 22%ile, P = 0.93). However, by 6 months postoperative, median weight percentile improved to 63% in the UCB-MNC treated group, but declined to 8% in controls (P = 0.02). UCB-MNC therapy appears to limit the initial negative impact on RV FAC and EF seen after stage II surgery. During early follow up, FAC and weight percentile improved in UCB-MNC patients relative to controls, suggesting a beneficial effect of UCB-MNC therapy.

Inhibiting Very Long Chain Acyl-CoA Dehydrogenase (VLCAD) Induces Selective Leukemia Cell Death

Targeting cell metabolism has emerged as a viable treatment strategy in acute myeloid leukemia (AML), a malignant hematological disease characterized by poor patient outcomes and limited chemotherapeutic options. Compared to the normal hematopoietic population, leukemia cells exhibit an altered phenotype characterized by increased mitochondrial mass as well as a greater reliance on oxidative phosphorylation and fatty acid oxidation (FAO) for survival. Mitochondrial FAO is a four-reaction process that catabolizes fatty acids to acetyl-CoA, generating reductive equivalents for the electron transport chain (ETC) and anaplerotic intermediates for the TCA cycle. Clinically approved FAO inhibitors, such as trimetazidine and ranolazine, are tissue-specific, targeting FAO in some tissues but affecting additional pathways in others. To better understand the potential clinical utility of targeting FAO, we systematically tested a panel of clinical and pre-clinical FAO inhibitors, reasoning that the most potent FAO inhibitor would lead to a novel anti-AML target. Avocadyne was the most potent anti-AML compound, inducing leukemic cell death (EC50: 2.5 µM) and suppressing clonogenic growth of primary samples, while sparing normal hematopoietic cells. Further, avocadyne (100mg/kg twice weekly for 5 weeks) reduced patient-derived AML cell engraftment in the bone marrow of immune deficient mice. As a component of avocatin-B, a mixture of two fatty alcohols previously determined to accumulate in the mitochondria, we confirmed that avocadyne inhibited long chain FAO using radiolabeled studies and high resolution respirometry. To identify a molecular target, avocadyne treated cells were immunoprecipitated with antibodies against each intramitochondrial enzyme involved in long chain FAO (e.g., very long acyl-CoA dehydrogenase (VLCAD; step 1) and the alpha and beta subunits of the mitochondrial trifunctional protein: HADHA, HADHB; steps 2-4). Immunoblotting and LC/MS analysis confirmed that avocadyne co-eluted with VLCAD, but not with HADHA or HADHB, confirming a direct physical interaction between avocadyne and VLCAD. VLCAD introduces a double bond to a fully saturated long chain fatty acid and reduces electron transfer flavoprotein (ETF)-bound FAD, transferring these electrons to the ETC. Using fluorescence spectrophotometry and respirometry, avocadyne directly inhibited VLCAD activity, resulting in reduced ETF-supported respiration. The activity of MCAD, an acyl-CoA dehydrogenase catalyzing medium chain fats, was not affected, suggesting avocadyne inhibits long chain FAO exclusively. Further, profiling of acyl-carnitines following avocadyne treatment also showed a pattern characteristic of long chain FAO inhibition at VLCAD. To further understand how VLCAD modulated avocadyne sensitivity, avocadyne-resistant and VLCAD knockdown cells were generated. Lentiviral knockdown of VLCAD sensitized leukemic cells to avocadyne-induced FAO inhibition and death. In contrast, cells resistant to avocadyne had increased protein expression of VLCAD but no change in other long chain FAO enzymes. With increased VLCAD-supported ETF respiration, higher concentrations of avocadyne were required to induce cell death, compared to the parental line. These results show that VLCAD expression modulated leukemic sensitivity to avocadyne. Inhibiting FAO at VLCAD triggered an adaptive metabolic switch towards glycolysis, characterized by increased extracellular acidification. This compensatory increase in glycolysis was ultimately insufficient to prevent the depletion of TCA metabolites and ATP, leading to leukemic death. In contrast, following avocadyne treatment, normal umbilical cord blood-derived mononuclear cells increased glycolytic as well as pyruvate dehydrogenase activity and had no decrease in ATP levels, cell viability, or clonogenic growth. Together, these results highlight, for the first time, VLCAD as a novel anti-AML target and further suggest the clinical utility of FAO inhibition as a potential anti-AML strategy. Disclosures Minden: Trillium Therapetuics: Other: licensing agreement. Schimmer:Medivir Pharmaceuticals: Research Funding; Jazz Pharmaceuticals: Consultancy; Novartis Pharmaceuticals: Consultancy; Otsuka Pharmaceuticals: Consultancy.

SMALL-MOLECULE INHIBITOR TARGETING P62 ATTENUATES THE LEUKEMIA-INITIATION POTENTIAL OF ACUTE MYELOID LEUKEMIA CELLS

In recent years there has been an increased focus on the tumorigenesis potential of leukemia initiation cells (LICs) in acute myeloid leukemia (AML). Targeting LICs strategy is hopefully to eradicate leukemia cells in drug development. Autophagy plays a critical role in hematopoietic stem cell life-long maintenance, cancer progression and chemoresistance. p62 (sequestosome 1,SQSTM1) serves as a selective autophagy receptor for degradation of ubiqutinated substrates and loss of p62 impairs leukemia progression in AML mouse model. LP1-106 is a p62-ZZ inhibitor, which was identified through 3D homology modeling and virtual screening molecular docking studies. In this study, we investigated the in vitro and in vivo effects of LP1-106 based on human AML cell lines, primary AML cells and MLL-AF9 AML mouse model. Cytotoxicity and apoptosis assays showed that LP1-106 could significantly inhibit cell proliferation and induce apoptosis. Serial colony-forming unit assays suggested that in vitro treatment with LP1-106 induced a sharp decrease in number of type A colony, which displays higher leukemia-initiation potential. In vivo assay implied that LP1-106 could attenuate myeloid leukemia progression in mice by impairing LICs. Additionaly, we evaluated the safty of LP1-106 in normal human umbilical cord blood-derived mononuclear cells (hUCB-MNCs), which suggested that LP1-106 has no severe impact on nomal hematopoiesis under effective concentration. Our data showed that this small-molecule inhibitor LP1-106 targeting p62-ZZ domain possesses the potential of LICs-surpression. These positive results provide a pharmacological basis for further study of this compound, therefore we plan to continue our research on the leukemia-inhibition mechanism of LP1-106 and its possible clinical application on the treatment of AML incombination with conventional antineoplastic agents.

Autologous stem cell therapy for hypoplastic left heart syndrome: Safety and feasibility of intraoperative intramyocardial injections

ObjectivesStaged surgical palliation for hypoplastic left heart syndrome results in an increased workload on the right ventricle serving as the systemic ventricle. Concerns for cardiac dysfunction and long-term heart failure have generated interest in first-in-infant, cell-based therapies as an additional surgical treatment modality. MethodsA phase 1 clinical trial was conducted to evaluate the safety and feasibility of direct intramyocardial injection of autologous umbilical cord blood-derived mononuclear cells in 10 infants with hypoplastic left heart syndrome at the time of stage II palliation. ResultsAll 10 patients underwent successful stage II palliation and intramyocardial injection of umbilical cord blood-derived mononuclear cells. Operative mortality was 0%. There was a single adverse event related to cell delivery: An injection site epicardial bleed that required simple oversew. The cohort did not demonstrate any significant safety concerns over 6 months. Additionally, the treatment group did not demonstrate any reduction in cardiac function in the context of the study related intramyocardial injections of autologous cells. ConclusionsThis phase 1 clinical trial showed that delivering autologous umbilical cord blood-derived mononuclear cells directly into the right ventricular myocardium during planned stage II surgical palliation for hypoplastic left heart syndrome was safe and feasible. Secondary findings of preservation of baseline right ventricular function throughout follow-up and normalized growth rates support the design of a phase 2b follow-up trial.

Translational Regenerative Therapies for Chronic Spinal Cord Injury.

Spinal cord injury is a chronic and debilitating neurological condition that is currently being managed symptomatically with no real therapeutic strategies available. Even though there is no consensus on the best time to start interventions, the chronic phase is definitely the most stable target in order to determine whether a therapy can effectively restore neurological function. The advancements of nanoscience and stem cell technology, combined with the powerful, novel neuroimaging modalities that have arisen can now accelerate the path of promising novel therapeutic strategies from bench to bedside. Several types of stem cells have reached up to clinical trials phase II, including adult neural stem cells, human spinal cord stem cells, olfactory ensheathing cells, autologous Schwann cells, umbilical cord blood-derived mononuclear cells, adult mesenchymal cells, and autologous bone-marrow-derived stem cells. There also have been combinations of different molecular therapies; these have been either alone or combined with supportive scaffolds with nanostructures to facilitate favorable cell–material interactions. The results already show promise but it will take some coordinated actions in order to develop a proper step-by-step approach to solve impactful problems with neural repair.

Effect of human umbilical cord blood-derived mononuclear cells on diabetic nephropathy in rats

Diabetic nephropathy (DN) is damage to the kidney which can lead to chronic renal failure, eventually requiring dialysis. Diabetes mellitus is the most common cause of adult kidney failure worldwide in the developed world. The current work was designed to elucidate the effect of mononuclear cells (MNCs) injection on reverse DN in rats exposed to streptozotocin (STZ) injection compared to metformin as a known hypoglycemic drug, 40 Male rats were divided equally into 4 groups; normal control group, diabetic control group, MNCs group were diabetic rats treated with MNCs (30×106 MNCs/rat once iv dose) in the tail vein of the rat, and metformin group were diabetic rats treated with metformin (100mg/kg orally daily dose) for four weeks. The results indicated an improvement effect of MNCs and metformin on STZ-induced DN in rats, which was evidenced by significant decrease in urinary albumin/creatinine ratio, N-acetyl-β-d-glucosaminidase (NAG), urinary kidney injury molecule-1 (KIM-1), serum urea, serum creatinine and fasting blood glucose and significant increase in C- peptide level, compared to diabetic control group. Additionally MNCs treated group exhibited pronounced effects in all previous parameters compared to metformin treated group. It is proved that MNCs treatment was superior to metformin in controlling hyperglycemia, and improving renal function in diabetic rats.

Transplantation of human umbilical cord blood-derived mononuclear cells induces recovery of motor dysfunction in a rat model of Parkinson&amp;#39;s disease

Transplantation of human umbilical cord blood-derived mononuclear cells induces recovery of motor dysfunction in a rat model of Parkinson's disease Chao Chen,1,* Jing Duan,1,* Aifang Shen,2,* Wei Wang,1 Hao Song,1 Yanming Liu,1 Xianjie Lu,1 Xiaobing Wang,2 Zhiqing You,1 Zhongchao Han,3,4 Fabin Han1 1Center for Stem Cells and Regenerative Medicine, The Liaocheng People's Hospital, Affiliated Liaocheng Hospital, Taishan Medical University, Shandong, People's Republic of China; 2Department of Gynecology and Obstetrics, The Liaocheng People's Hospital, Affiliated Liaocheng Hospital, Taishan Medical University, Shandong, People's Republic of China; 3The State Key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences, Peking Union of Medical College, Tianjin, People's Republic of China; 4National Engineering Research Center of Cell Products, AmCellGene Co. Ltd., TEDA, Tianjin, People's Republic of China*These authors contributed equally to this workAbstract: Human umbilical cord blood-derived mononuclear cells (hUCB-MNCs) were reported to have neurorestorative capacity for neurological disorders such as stroke and traumatic brain injury. This study was performed to explore if hUCB-MNC transplantation plays any therapeutic effects for Parkinson's disease (PD) in a 6-OHDA-lesioned rat model of PD. hUCB-MNCs were isolated from umbilical cord blood and administered to the striatum of the 6-OHDA-lesioned rats. The apomorphine-induced locomotive turning-overs were measured to evaluate the improvement of motor dysfunctions of the rats after administration of hUCB-MNCs. We observed that transplanted hUCB-MNCs significantly improve the motor deficits of the PD rats and that grafted hUCB-MNCs integrated to the host brains and differentiated to neurons and dopamine neurons in vivo after 16 weeks of transplantation. Our study provided evidence that transplanted hUCB-MNCs play therapeutic effects in a rat PD model by differentiating to neurons and dopamine neurons. Keywords: hUCB-MNCs, Parkinson's disease, transplantation, differentiation, dopamine neurons

Culture and differentiation of cytokine-induced killer cells from umbilical cord blood-derived mononuclear cells

Cytokine-induced killer cells (CIK) are cytotoxic T cells, which have both NK and T cell properties. These cells are characterized by potent, non-MHC-restricted cytotoxicity and reduced alloreactivity, which make them appealing for use in adoptive immunotherapy of cancer and virus infections. In this study, CIK cells were generated by stimulating umbilical cord blood-derived mononuclear cells (UCB-MNCs) with interferon-gamma (IFN-g) on day 0. Anti-CD3 antibody and interleukin-2 (IL-2) were added after 24 hours at four different experimental concentration combinations in order to identify the optimal cytokine amounts for CIK cell proliferation. Cells were collected at four time points over a 21-day period (day 0, 7, 14, 21) for analysis of cell marker presentation using flow cytometry, as well as transcription-level cytokine production using RT-PCR. The results showed that in the 21-day culture, the average final expansion levels of CD3+CD56+ CIK cell were in the range of hundredfold, accounted for 26% in the bulk culture. Most important, these cells strongly expressed granzyme B (80.87%), a potent factor involved in cell-mediated cytotoxicity. These CIK cells also transcriptionally overexpressed the three cytokine genes that produce IFN-g, tumor necrosis factor-alpha (TNF-a), and IL-2; these are key for immune cell mobilization against tumors as well as foreign pathogens. Our research establishes an effective cytokine concentration and time protocol for use in generation of CIK cells from UCB-MNCs, potentiating greater applications of CIK cell-adoptive immunotherapy in both research and clinical settings. Thus, the 3­rd and 4th experimental conditions both stimulated CIK cell differentiation with 50 ng/ml of anti-CD3 antibody, but with IL-2 concentrations of 500 U/ml and 1000 U/ml, respectively.

Umbilical Cord Blood-Derived Mononuclear Cells Exhibit Pericyte-Like Phenotype and Support Network Formation of Endothelial Progenitor Cells In Vitro.

Umbilical cord blood represents a promising cell source for pro-angiogenic therapies. The present study examined the potential of mononuclear cells (MNCs) from umbilical cord blood to support endothelial progenitor cell (EPC) microvessel formation. MNCs were isolated from the cord blood of 20 separate donors and selected for further characterization based upon their proliferation potential and morphological resemblance to human vascular pericytes (HVPs). MNCs were screened for their ability to support EPC network formation using an in vitro assay (Matrigel™) as well as a reductionist, coculture system consisting of no additional angiogenic cytokines beyond those present in serum. In less than 15% of the isolations, we identified a population of highly proliferative MNCs that phenotypically resembled HVPs as assessed by expression of PDGFR-β, NG2, α-SMA, and ephrin-B2. Within a Matrigel™ system, MNCs demonstrated pericyte-like function through colocalization to EPC networks and similar effects as HVPs upon total EPC tubule length (p=0.95) and number of branch points (p=0.93). In a reductionist coculture system, MNCs served as pro-angiogenic mural cells by supporting EPC network formation to a significantly greater extent than HVP cocultures, by day 14 of coculture, as evidenced through EPCtotal tubule length (p<0.0001) and number of branch points (p<0.0001). Our findings are significant as we demonstrate mural cell progenitors can be isolated from umbilical cord blood and develop culture conditions to support their use in microvascular tissue engineering applications.

Safety and feasibility for pediatric cardiac regeneration using epicardial delivery of autologous umbilical cord blood-derived mononuclear cells established in a porcine model system.

Congenital heart diseases (CHDs) requiring surgical palliation mandate new treatment strategies to optimize long-term outcomes. Despite the mounting evidence of cardiac regeneration, there are no long-term safety studies of autologous cell-based transplantation in the pediatric setting. We aimed to establish a porcine pipeline to evaluate the feasibility and long-term safety of autologous umbilical cord blood mononuclear cells (UCB-MNCs) transplanted into the right ventricle (RV) of juvenile porcine hearts. Piglets were born by caesarean section to enable UCB collection. Upon meeting release criteria, 12 animals were randomized in a double-blinded fashion prior to surgical delivery of test article (n=6) or placebo (n=6). The UCB-MNC (3×10(6) cells per kilogram) or control (dimethyl sulfoxide, 10%) products were injected intramyocardially into the RV under direct visualization. The cohorts were monitored for 3 months after product delivery with assessments of cardiac performance, rhythm, and serial cardiac biochemical markers, followed by terminal necropsy. No mortalities were associated with intramyocardial delivery of UCB-MNCs or placebo. Two animals from the placebo group developed local skin infection after surgery that responded to antibiotic treatment. Electrophysiological assessments revealed no arrhythmias in either group throughout the 3-month study. Two animals in the cell-therapy group had transient, subclinical dysrhythmia in the perioperative period, likely because of an exaggerated response to anesthesia. Overall, this study demonstrated that autologous UCB-MNCs can be safely collected and surgically delivered in a pediatric setting. The safety profile establishes the foundation for cell-based therapy directed at the RV of juvenile hearts and aims to accelerate cell-based therapies toward clinical trials for CHD.

A comparison of umbilical cord blood-derived endothelial progenitor and mononuclear cell transplantation for the treatment of acute hindlimb ischemia

Acute lower limb ischemia is a common peripheral artery disease whose treatment presents many difficulties. Stem cell transplantation is considered a novel and promising method of treating this disease. Umbili- cal cord blood (UCB) is rich in stem cells, including hematopoietic stem cells (HSCs), mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs). However, historically, banked umbilical cord blood has been used mainly to treat blood-related diseases. Therefore, this study compared the efficacy of umbilical cord blood- derived mononuclear cells (UCB-MNCs) with EPC transplantation for the treatment of acute hindlimb ischemia (ALI) in mouse models. MNCs were isolated from UCB by Ficoll gradient centrifugation, after which the EPCs were sorted based on CD34+ and CD133+ markers and cultured according to a previously published protocol. To induce ALI, mice were immuno-suppressed using busulfan (BU) and cyclophosphamide (CY), after which the femoral arteries were burned. Induction of ALI in the immune suppressed mice was confirmed by the grade of tissue damage, pedal frequency in water, tissue edema, changes in histology, total white blood cell count, and white blood cell composition. Model mice were injected with a dose of MNCs or EPCs and un-treated control mice were injected with phosphate buffered saline. The efficiency of treatment was evaluated by comparing the grade of tissue damage between the three groups of mice. Mice aged 6-12 months were suitable for ALI, with 100% of mice exhibiting ischemia from grade I 10%, grade III 50%, grade IV 40%. For all ALI mice, a gradual in- crease in pedal frequency in water, increased tissue edema, necrosis of muscle tissue, and loss of hindlimb func- tion were observed after 20 days. Transplanted MNCs and EPCs significantly improved hindlimb ischemia com- pared with control treatment. Moreover, EPC transplantation significantly improved hindlimb ischemia compared with MNC transplantation. Following EPC and MNC transplantation, 44.44% and 33.33% of the mice recovered fully (grade 0), respectively. Specifically, all recovered mice exhibited hindlimb activities similar to those of nor- mal mice. Transplantation of UCB-derived MNCs and EPCs are promising therapies for hindlimb ischemia.

Conditioned Medium Originated From Lethally Irradiated Umbilical Cord Blood-Derived Mononuclear Cells Has Different Pro-Angiogenic Effects Over Mature and Progenitor Endothelial Cells In Vitro

IntroductionIschemic cardiovascular diseases are a leading cause of mortality in the industrialized world. Cell-based therapies have been tested to promote revascularization, mainly through the release and actions of paracrine factors that may prevent apoptosis and support migration and proliferation of resident endothelial cells (EC) and circulating endothelial progenitors (EPC). The mononuclear cell fraction of umbilical cord blood (CB-MNC) is rich in pluripotent progenitors and represents an attractive cell source for therapeutic angiogenesis. In order to demonstrate the paracrine action of CB-MNC we tested the angiogenic potential of conditioned medium (CM) derived from apoptotic CB-MNC evaluating the effects exerted over mature EC and peripheral blood (PB)-derived EPC in terms of proliferation, migration and capillary-network formation in vitro. MethodsHuman Umbilical Vein Endothelial Cells (HUVEC, Lonza) were cultured in Endothelial Basal Medium (EBM2) supplemented with SingleQuotes (EGM2). EPCs were obtained from PB as “Endothelial Colony Forming Cells” (ECFC). Both HUVEC and ECFC were used for subsequent experiments from passage 2 to passage 6.MNC were isolated from CB by density gradient centrifugation, gamma-irradiated (70Gy) to induce apoptosis and incubated in EBM2 for 72h to obtain the release of CM. CM was recovered from culture, centrifuged (4000 rpm 10 min) to remove cell debris and stored at -80°C. MNC viability after gamma-irradiation was evaluated by flow cytometry (7-AAd staining). RayBio Human Angiogenesis Array and ELISA assays (to quantify PDGF-AB, VEGF165, EGF, IGF-I) were used to assess CM soluble factors content.The angiogenic potential of soluble factors released by gamma-irradiated MNC was assessed by Matrigel capillary-like network formation assay using the Transwell Permeable Supports and confirmed using the sole CM in the Matrigel assay. CM capacity to support HUVEC and ECFC viability was assessed by the MTT assay and the capacity to induce HUVEC and ECFC migration by the Chemicon Cell Migration Assay. EBM2 was used as control medium. All experiments were repeated at least 4 times. ResultsGamma-irradiation induced a significant time-dependent reduction in MNC viability (p<0.05), reaching 41±7% at 72h. The difference in viability decrease between irradiated and not irradiated MNC was statistically significant over time (p<0.001).CM contained various cytokines and growth factors involved in the regulation of angiogenesis, wound healing, extracellular matrix remodeling and inflammation as showed by Angiogenesis Array. ELISA assays showed that irradiated MNC released an increasing amount of PDGF-AB, VEGF165 and EGF over time, while IGF-I was not detected in the CM.Soluble factors released from irradiated MNC in the Transwell system showed a significant pro-angiogenic effect over HUVEC (p<0.001, Figure 1a) as well as over ECFC (p<0.001, Figure 1b). [Display omitted] Results obtained with the Matrigel Transwell system using irradiated MNC were confirmed employing CM from irradiated MNC cultured 72 hours: CM induced capillary-like network formation in both HUVEC (p<0.001, Figure 1c) and ECFC (p<0.01, Figure 1d).CM compared to control medium significantly increased HUVEC viability (p<0.05, Figure 2a) but not ECFC viability (Figure 2b) and significantly enhanced migration of both HUVEC (p<0.001, Figure 3a) and ECFC (p<0.001, Figure 3b). [Display omitted] [Display omitted] ConclusionOur experiments show that soluble factors released by lethally irradiated CB-MNC have an important angiogenic effect, inducing HUVEC but not ECFC proliferation, HUVEC and ECFC migration and capillary network formation in vitro. These results outline an interesting difference between mature and progenitor EC in their response to CM, which may reflect the different physiological roles that mature and progenitor EC exert during angiogenesis.This study confirms the paracrine effect of factors released from stem cells contained in the MNC fraction, which could be exploited in regenerative medicine to induce therapeutic revascularization using CB, an easy available stem cells source. Disclosures:No relevant conflicts of interest to declare.

Human umbilical cord blood-derived mononuclear cell transplantation: case series of 30 subjects with Hereditary Ataxia

BackgroundThe differential diagnosis for hereditary ataxia encompasses a variety of diseases characterized by both autosomal dominant and recessive inheritance. There are no curative treatments available for these neurodegenerative conditions. This open label treatment study used human umbilical cord blood-derived mononuclear cells (CBMC) combined with rehabilitation training as potential disease modulators.Methods30 patients suffering from hereditary ataxia were treated with CBMCs administered systemically by intravenous infusion and intrathecally by either cervical or lumbar puncture. Primary endpoint measures were the Berg Balance Scale (BBS), serum markers of immunoglobulin and T-cell subsets, measured at baseline and pre-determined times post-treatment.ResultsA reduction of pathological symptoms and signs was shown following treatment. The BBS scores, IgG, IgA, total T cells and CD3+CD4 T cells all improved significantly compared to pre-treatment values (P < 0.01~0.001). There were no adverse events.ConclusionThe combination of CBMC infusion and rehabilitation training may be a safe and effective treatment for ataxia, which dramatically improves patients' functional symptoms. These data support expanded double blind, placebo-controlled studies for these treatment modalities.

Effects of plant lectin and extracts on adhesion molecules of endothelial progenitors

Abstract Promise of cell therapy has advanced the use of adult stem cells towards the development of novel approaches to promote regeneration of injured endothelium. The aim of this study was to stimulate endothelial progenitor cells (EPCs) with lectin isolated from Solanum tuberosum (potato) shoot and Calendula officinalis (marigold) extracts, in order to increase EPCs proliferation and gene expression of molecules with roles in chemotaxis and adhesion for a better attachment to injured vascular tissue. EPCs were differentiated from umbilical cord blood-derived mononuclear cells and characterized by light microscopy, flow cytometry, and vascular tube-like structures formation on Matrigel. Cell proliferation was determined by MTS assay, and gene expression of molecules involved in EPCs adhesion (VCAM-1, VE-cadherin, ICAM-1, PECAM-1, P-selectin) and chemotaxis was determined (CXCR4, Tie-2) by RT-PCR. For the assessment of cell motility, wound-healing assay was employed. Both potato shoot lectin and marigold extracts stimulated EPCs proliferation in a concentration dependent manner and were able to increase expression of adhesion and chemotactic molecules. Marigold flower extract proved to be more efficient. This study demonstrates the usefulness of potato lectin and marigold extracts to increase EPCs proliferation and modulate gene expression of chemotactic and adhesion molecules, which may facilitate EPCs attachment to injured endothelium.

Taurine Supports Preservation of Proendocrine Cell Types in Human Umbilical Cord Blood-Derived Mononuclear Cells During Cryostorage

Background We demonstrated earlier that a subset of human umbilical cord-blood (hUCB)-derived mononuclear cells (MNCs) express proendocrine transcription factors and exhibit potential to differentiate into endocrine pancreatic lineage. The growing interest in the use of MNCs for diabetes has promoted cryopreservation of these cells for future use in translational research. Development of optimal cryopreservation media is critical to the success of translational research. Methods We explored protective effects of taurine in cryopreservation of hUCB-derived MNCs. MNCs were isolated using Histopaque and 3 million viable cells were cryofrozen using 10% dimethyl sulfoxide (v/v) in fetal bovine serum or supplemented with taurine (0.3/3.0 mmol/L). Cryopreservation conditions were assessed based on their viability, growth, and ability to retain endocrine pancreatic transcription factor expressing cells. Results UCB-derived MNCs adhered and grew as mesenchymal-like cells in culture following revival from various cryopreservation conditions. Interestingly, MNCs expressed threefold more ngn3, 2-fold more nkx6.1, and 15-fold more isl1 transcripts in taurine-supplemented cryo-medium compared to the conventional cryomix. Conclusion The present study demonstrates that taurine supplementation to cryopreservation media improved retention of endocrine pancreatic transcription factor-expressing MNCs.

Differentiation of human umbilical cord blood-derived mononuclear cells to endocrine pancreatic lineage

Generation of insulin-producing cells remains a major limitation for cellular replacement therapy in treatment of diabetes. To understand the potential of human umbilical cord blood (hUCB)-derived mononuclear cells (MNCs) in cell replacement therapy for diabetes, we studied MNCs isolated from 270 human umbilical cord blood samples. We characterized these by immunostaining and real-time PCR and studied their ability to differentiate into insulin-producing cells. We observe that freshly isolated MNCs as well as mesenchymal-like cells grown out by in vitro culture of isolated MNCs express key pancreatic transcription factors: pdx1, ngn3, isl1, brn4 and pax6. However, after 32-fold expansion, MNCs show decreased abundance of pdx1 and ngn3, indicating that islet/pancreatic progenitors detected in freshly isolated MNCs die or are diluted out during in vitro expansion. We therefore transplanted freshly isolated MNCs in NOD/SCID (immuno-incompetent) or FVB/NJ (immuno-competent) mice to check their ability to differentiate into insulin-producing cells. We observe that after 9 weeks of transplantation, ~25% grafts exhibit human insulin-producing (16% immunopositive) cells. The number and abundance of pro-insulin transcript-containing cells increased when the animals underwent partial pancreatectomy, 15 days after transplantation. Our results indicate that such hUCB-derived MNC population contains a subset of “pancreas-committed” cells that have the potential to differentiate into insulin-producing cells in vivo. Further studies in understanding the differentiation potential of this subset of pancreas-committed hUCB-derived MNCs will provide us with an autologous source of “lineage-committed” progenitors for cell replacement therapy in diabetes.

Cytokine secretion by hUCB-derived mononuclear cells – a putative mediator of functional improvement after hypoxic-ischemic brain lesion?

Intraperitoneal transplantation of human umbilical cord blood-derived mononuclear cells led to the “homing“ of these cells specifically to a hypoxic-ischemic lesion in perinatal rats. Motor deficits resulting from the lesion were alleviated upon transplantation (1). However, the molecular and cellular mechanisms underlying the functional improvement are still unclear. As neuronal differentiation of transplanted cells seems to be a rare or absent event in vivo, we propose secondary mechanisms, which might be responsible for the therapeutic effects. One possibility is that transplanted cells might contribute to a regenerative environment by secretion of cytokines.

Endothelial progenitor cell differentiation using cryopreserved, umbilical cord blood-derived mononuclear cells

To investigate the endothelial differentiation potentiality of umbilical cord blood (UCB), we induced the differentiation of endothelial progenitor cells (EPC) from cryopreserved UCB-derived mononuclear cells (MNC). MNC from cryopreserved UCB and peripheral blood (PB) were cultured in M199 medium with endothelial cell growth supplements for 14 d. EPC were characterized by RT-PCR, flow cytometry, and immunocytochemistry analysis. The proliferation of differentiated EPC was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, and vascular endothelial growth factor (VEGF) concentration was measured using an ELISA kit. Characteristics of UCB-derived EPC were compared with those of PB-derived EPC. A number of round-shaped cells were loosely attached to the bottom after 24 h culture, and numerous spindleshaped cells began to appear from the round-shaped ones on d 7. Those cells expressed endothelial markers such as, Flt-1/VEGFR-1, ecNOS, VE-cadherin, von Willebrand factor, and secreted VEGF. The patterns of endothelial markers of EPC from PB and UCB did not show striking differences. The results of the proliferation and secretion of VEGF were also similar. We successfully cultured UCB cells stored at -196 Celsius degree into cells with the quality of endothelial cells. Those EPC could be used for angiogenic therapeutics by activating adjacent endothelial cells and enhancing angiogenesis.