How do we assess batch-to-batch consistency between extracellular vesicle products?

BACKGROUND: Extracellular vesicles (EVs) have gained interest in the field of regenerative and transfusion medicine. Specifically, current Good Manufacturing Practice (cGMP)-grade EVs produced by mesenchymal stromal cells (MSCs) are an intriguing option for cell-free therapeutics. With the development of cGMP-grade EV products, a simple and reliable method for batch-to-batch consistency is needed. STUDY DESIGN AND METHODS: The objective of this study was to validate a method to semiquantitatively assess the batch-to-batch consistency of isolated EVs. A multiplex bead-based flow cytometric assay containing 37 surface markers and 2 assay control antibody-coated capture beads was validated. Detection limits (n = 10 buffer samples), repeatability (n = 9 EV samples), and intra-observer reproducibility over 2 days (n = 10 EV batches) were assessed. A Spearman correlation matrix was used to evaluate the batch-to-batch consistency of independently isolated EV products (n = 37 surface markers). Batches with a Spearman correlation coefficient ≥0.9 and p < 0.05 were considered statistically indistinguishable from previous batches. RESULTS: This assay demonstrated robust repeatability as well as intra- and inter-assay reproducibility. In-house batches of EVs were significantly correlated (r ≥ 0.90; p ≤ 1×10-14 ). Compared with buffer, EV batches had correlation coefficients near zero (r ≤ -0.10; p ≥ 0.12). Commercially sourced EVs significantly correlated with in-house EV batches, but fell below the 90% correlation cutoff (r ≤ 0.71; p ≤ 0.0004). DISCUSSION: This time-efficient and technically simple assay offers a robust method of quality control for assessing the batch-to-batch reproducibility of cGMP-grade EV products.

Mesenchymal Stem Cell Therapy in Acute Intracerebral Hemorrhage: A Dose-Escalation Safety and Tolerability Trial.

BACKGROUND: We conducted a preliminary phase I, dose-escalating, safety, and tolerability trial in the population of patients with acute intracerebral hemorrhage (ICH) by using human allogeneic bone marrow-derived mesenchymal stem/stromal cells. METHODS: Eligibility criteria included nontraumatic supratentorial hematoma less than 60 mL and Glasgow Coma Scale score greater than 5. All patients were monitored in the neurosciences intensive care unit for safety and tolerability of mesenchymal stem/stromal cell infusion and adverse events. We also explored the use of cytokines as biomarkers to assess responsiveness to the cell therapy. We screened 140 patients, enrolling 9 who met eligibility criteria into three dose groups: 0.5 million cells/kg, 1 million cells/kg, and 2 million cells/kg. RESULTS: Intravenous administration of allogeneic bone marrow-derived mesenchymal stem/stromal cells to treat patients with acute ICH is feasible and safe. CONCLUSIONS: Future larger randomized, placebo-controlled ICH studies are necessary to validate this study and establish the effectiveness of this therapeutic approach in the treatment of patients with ICH.

Considerations for immune effector cell therapy collections: a white paper from the American Society for Apheresis.

BACKGROUND AIMS: This white paper was developed to provide leukapheresis guidance for the collection of mononuclear cells from adult and pediatric patients who are destined for immune effector cell (IEC) therapies for commercial and research applications. Currently, there is considerable variability in leukapheresis processes and limited published information regarding best practices relevant to new cellular therapies, especially IECs. Herein the authors address critical leukapheresis questions in five domains to help guide consistent collection processes and ensure high-quality products. The first four domains are onboarding, pre-collection, collection and post-collection, with protocol feasibility, preparation, care and follow-up of the patient/donor at each step, respectively, and technical considerations during collection. The fifth domain of quality assurance focuses on ensuring product potency, purity, safety and auditing. METHODS: The American Society for Apheresis (ASFA) Clinical Applications Committee (IEC Therapy Subcommittee) was charged by the society's board of directors with working collaboratively with other ASFA committees and organizations, including the Foundation for the Accreditation of Cellular Therapy, Association for the Advancement of Blood and Biotherapies, American Society for Transplantation and Cellular Therapy, National Marrow Donor Program and International Society for Cell & Gene Therapy, to develop guidelines regarding leukapheresis collection of cells destined for the manufacture of IEC therapies. After a review of the literature and discussion with members of the involved committees and various institutions, a draft guidance was created and circulated for comment and revision. RESULTS: Critical aspects of apheresis that could affect the quality and quantity of the leukapheresis product were identified. These areas were then discussed and reviewed. After consensus, the best practice guidelines were proposed and accepted. CONCLUSIONS: In the current era of rapid growth of IEC therapies, it is important to address critical leukapheresis steps to provide high-quality products and more consistent practices and to eliminate redundant efforts.

Mesenchymal stem cell therapy for focal epilepsy: A systematic review of preclinical models and clinical studies.

Drug-resistant epilepsy (DRE) is characterized by recurrent seizures despite appropriate treatment with antiseizure medication (ASM). Due to their regenerative and immunomodulatory potential, therapies with biologics such as mesenchymal stem cells (MSCs) offer a potential therapeutic benefit for structural causes of epilepsy, such as hippocampal sclerosis. In this article, we report a systematic review of the literature evaluating the preclinical and clinical studies of MSCs for DRE. Medline, Ovid EMBASE, Scopus, and the Cochrane Databases were searched electronically from their dates of inception to November 2021 using the following keywords: (("mesenchymal") AND ("stem cell")) AND (("epilepsy") OR ("convulsion") OR ("seizures")). This review followed Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines. The initial query identified 488 studies representing 323 unique manuscripts. After application of selection criteria, 15 studies were included in this systematic review; 11 were preclinical studies and 4 were clinical studies. All preclinical studies were performed in rodents and all clinical studies were phase 1 trials. Thus far, therapy with MSCs appears to be safe for use in humans, as no severe adverse events related directly to the therapy were reported. Furthermore, MSC therapy appears to provide a statistically significant clinical benefit by reducing the seizure burden of patients, reducing the electrophysiological biomarkers of epilepsy, and improving their comorbidities, such as depression and anxiety. In addition, animal studies reveal that the therapy exerts its effect by reducing aberrant mossy fiber sprouting (reduce excitatory pathways) and increasing γ-aminobutyric acid (GABA)ergic interneurons (increase inhibitory pathways). Both preclinical and clinical studies have shown MSC therapy to be safe and preliminary effective, thus warranting further studies to investigate its therapeutic potential.

Lack of defined apheresis collection criteria in publicly available CAR-T cell clinical trial descriptions: Comprehensive review of over 600 studies.

BACKGROUND: Chimeric antigen receptor T (CAR-T) cell successes have encouraged continued clinical study. Apheresis collection of starting material for CAR-T cell therapy product manufacturing is critical but described approaches suggest variability and clinical guidelines are currently lacking. The goal of this study was to gather and assess variability in apheresis collection descriptions in publicly available CAR T-cell therapy clinical trials. STUDY DESIGN: We searched clinicaltrials.gov (a publicly available clinical trial database) for "chimeric antigen receptor T cells" on July 01, 2020 and studies accessed July 30, 2020-August 15, 2020. Data collected included date posted, study characteristics, apheresis mentions (number, location, and context), laboratory parameters and transfusion allowances. Apheresis context was analyzed using a qualitative inductive approach of grounded theory method with open coding. Text was classified into 37 context codes, grouped into 12 categories, and then consolidated into patient, procedure, product, and miscellaneous themes. RESULTS: Apheresis was mentioned 1044 times in 322 (51.9%) of 621 total studies. Laboratory parameters mentioned included white blood cells (100 studies), absolute neutrophil count (220 studies), absolute lymphocyte count (102 studies), CD3+ cell (38 studies), hemoglobin (233 studies, 54 studies specified transfusion allowance), and platelet (269 studies, 48 studies specified transfusion allowance). CONCLUSIONS: Apheresis collection of CAR-T cell products is not well-defined in clinical study descriptions and the context is inconsistent. Laboratory parameters useful for apheresis collection are variably present and do not consistently align with current practices. Further exploration, and clinical guideline development will encourage alignment of apheresis collections for CAR-T cell products.

Application of Human Adipose-Derived Stem cells for Bone Regeneration of the Skull in Humans.

BACKGROUND: Archeological archives report cranioplasty as 1 of the oldest surgical procedures; however, it was not until the last century that true advances have been made. Alternative approaches are necessary to achieve optimal closure of the defect with fewer adverse effects. We aim to evaluate the use of human adipose-derived stem cells (hADSCs) alone or seeded in scaffolds as the main treatment for cranial bone defects and to assess human patient outcomes. METHODS: A systematic review was performed by querying PubMed, Ovid MEDLINE, EMBASE, and Cumulative Index to Nursing and Allied Health Literature databases with the MeSH terms: "adipose-derived stem cells," "cranial bone defect," "stromal vascular factor," "fat grafting," as well as synonyms in combinations determined by our search strategy. We included human models that used hADSCs as primary therapy. We excluded studies in languages other than English. RESULTS: One hundred ninety-four studies were identified after removal of duplicates. Four articles that used hADSCs as the main therapy to treat calvarial defects in humans were included. One article applied the cell therapy alone, and 3 used ß-tricalcium phosphate granules as a scaffold to seed the hADSCs. CONCLUSIONS: Bone regeneration was reached in a short and intermediate period using autologous hADSCs in humans with no major adverse effects in all 4 articles included. A long-term follow-up study (6 years) exhibited late infections and reabsorption of the ß-tricalcium phosphate scaffold seeded with hADSCs.

Challenges of manufacturing mesenchymal stromal cell-derived extracellular vesicles in regenerative medicine.

The field of regenerative medicine has expanded greatly in the past decade, with more than 1000 current clinical trials involving mesenchymal stromal cell (MSC) treatment. Multiple recent publications have demonstrated that the beneficial effects from MSCs are not simply due to engraftment into the target organ as classically thought but rather are largely attributable to the release of paracrine factors including cytokines, growth factors and extracellular vesicles (EVs). These EVs contain miRNAs, free fatty acids and proteins that promote regeneration, proliferation and cell function and improve inflammation. Although EVs have shown promising results in animal studies, there are many obstacles to the manufacturing of EVs for clinical applications. This review discusses challenges associated with the manufacturing of clinical-grade EVs in regard to identity, purity, reproducibility, sterility, storage, potency and safety. We discuss currently employed methods and approaches for developing clinical Good Manufacturing Practices (GMP)-grade EVs and the limitations for each. We further discuss the best approaches to overcome the current hurdles in developing clinical GMP-grade EVs.

Low baseline platelet count predicts poor response to plerixafor in patients with multiple myeloma undergoing autologous stem cell mobilization.

BACKGROUND AIMS: Baseline platelet count has been shown to be a sensitive predictor of autologous peripheral blood progenitor cell collection yield in patients with multiple myeloma mobilized with granulocyte colony-stimulating factor (G-CSF). Patients who mobilize poorly with G-CSF are often treated with plerixafor to enhance mobilization. There are no surrogate markers available to predict response to plerixafor. METHODS: We retrospectively analyzed data from 73 patients with multiple myeloma who did not have adequate mobilization with G-CSF alone and were treated with plerixafor as a rescue agent. RESULTS: We found that baseline platelet count directly correlated with peripheral blood CD34+ (PB-CD34+) count after plerixafor treatment (r = 0.36, P < 0.0001) and the number of PB-CD34+ cells collected on the first day of apheresis and inversely correlated with the number of apheresis sessions needed to collect the target number of PB-CD34+ cells (P = 0.0015). Baseline platelet count of 153 000/µL or less was associated with 90% specificity of predicting poor response to plerixafor with a sensitivity of 33%. CONCLUSIONS: Baseline platelet count is a good predictor of mobilization response to plerixafor in patients with multiple myeloma.

A Combined Approach to Intracerebral Hemorrhage: Intravenous Mesenchymal Stem Cell Therapy with Minimally Invasive Hematoma Evacuation.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent stromal cells currently being tested as therapy for a variety of diseases. MSC therapy and hematoma evacuation using a minimally invasive approach are being studied separately to improve clinical outcomes after stroke. We report the first case of a patient with intracerebral hemorrhage (ICH) treated with combination MSC therapy and endoscopic hematoma evacuation. CASE REPORT: A 36-year-old woman with a past medical history of essential chronic hypertension and right lung bronchial atresia presented to the emergency department with acute neurologic decline (National Institute of Health Stroke Scale [NIHSS] score, 22). Computed tomography showed a 4.4 × 3.5 × 3.5 cm right basal ganglia hemorrhage with intraventricular extension. An external ventricular drain was placed, and she was enrolled in a Phase I clinical trial investigating intravenous MSC therapy for acute ICH. Continued neurologic deterioration due to increased intracranial pressure led to minimally invasive hematoma evacuation using the Artemis Neuro Evacuation Device (Penumbra, Inc.) on hospital day 4. Follow-up scans showed decreased density and extent of hemorrhage. She was discharged on day 41 with improved neurologic function scores (NIHSS score, 2). At 3-month follow-up, she was walking on her own, but had residual left arm and hand weakness (modified Rankin Score, 2). CONCLUSIONS: This case report suggests that the combination of MSC therapy and minimally invasive hematoma evacuation may be safe and well tolerated. Further larger randomized clinical trials are required to identify whether MSC therapy in combination with minimally invasive hematoma evacuation is safe, tolerable, and potentially improves outcomes than either alone.

Elevated Neutrophil-Lymphocyte Ratio is Predictive of Poor Outcomes Following Aneurysmal Subarachnoid Hemorrhage.

Background Recent studies of patients with intracerebral hemorrhage suggest an association between peripheral blood neutrophil-lymphocyte ratio and neurologic deterioration. We aimed to study the prognostic utility of neutrophil-lymphocyte ratio in predicting inpatient mortality in aneurysmal subarachnoid hemorrhage. Methods We conducted a retrospective electronic medical record review of the clinical, laboratory, and radiographic data of patients with aneurysmal subarachnoid hemorrhage 18 years of age or older presenting to the neuroscience intensive care unit from January 1, 2011, to December 31, 2017. Patients with aneurysmal subarachnoid hemorrhage were divided into 2 groups (group 1, alive at discharge; group 2, deceased prior to discharge), and neutrophil-lymphocyte ratio laboratory mean values were recorded for each patient. Our primary outcome measure was inpatient mortality, and our secondary measure was incidence of pneumonia with hospitalization. Results We identified 403 patients with aneurysmal subarachnoid hemorrhage for the study. After exclusion criteria, 44 eligible patients were divided into the 2 groups (group 1, n = 32; group 2, n = 12). Mean neutrophil-lymphocyte ratio for group 1 was 11.53, and for group 2, 17.85 (P < .01). The mean neutrophil-lymphocyte ratio of those who developed pneumonia compared to those who did not was 15.28 versus 12.81, respectively (P = .39). A Kaplan-Meier plot demonstrated increased mortality among patients with a neutrophil-lymphocyte ratio equal to or greater than 12.5 compared to those with a neutrophil-lymphocyte ratio less than 12.5. Conclusions These preliminary data demonstrate that a neutrophil-lymphocyte ratio equal to or greater than 12.5 at admission predict higher inpatient mortality in patients with aneurysmal subarachnoid hemorrhage.

Impact of good and poor mobilizers on hematopoietic progenitor cell collection efficiency and product quality.

BACKGROUND: Mobilization regimen choice is a significant contributing factor for successful hematopoietic progenitor cell (HPC) collection by leukocytapheresis and reaching the target CD34+ cell dose. How mobilization regimen affects collection efficiency and the quality of products collected using the Spectra Optia apheresis instrument is not fully known. METHODS: We evaluated the impact of granulocyte-colony stimulating factor (GCSF) and GCSF/plerixafor mobilization regimens on CE and product composition. We studied 373 leukocytapheresis HPC collections for 147 autologous transplants from January 1, 2010 to December 31, 2014. Patients were categorized in two groups; good mobilizers, mobilized with GCSF only (GM) and poor mobilizers, mobilized with GCSF and Plerixafor (PM). RESULTS: Overall, compared with PM group, total nucleated cell (TNC) yield was significantly lower in GM group (P = <.001). In contrast, median percent mononuclear cell (MNC) collected from GM (86.5%) was significantly higher than products collected from PM group (79.5%; P < .001). Compared with GM group, CD34+ cell CE was about 10% lower in PM group (P < .008). In addition, daily CD34+ cell/Kg yield was significantly higher in GM (2.08 × 10/Kg) compared with PM group (1.64 x 10/Kg, P = .019). Overall, the median number of collections per patient was two for GM and three for PM (P = .004). CONCLUSION: Products collected from PM group contained higher TNC content relative to GM group but had lower MNC enrichment, CD34+ cell CE and daily CD34+ cell yield per Kg.

Characterization and cost-benefit analysis of automated bioreactor-expanded mesenchymal stem cells for clinical applications.

BACKGROUND: Expanding quantities of mesenchymal stem cells (MSCs) sufficient to treat large numbers of patients in cellular therapy and regenerative medicine clinical trials is an ongoing challenge for cell manufacturing facilities. STUDY DESIGN AND METHODS: We evaluated options for scaling up large quantities of bone marrow-derived MSCs (BM-MSCs) using methods that can be performed in compliance with Good Manufacturing Practices (GMP). We expanded BM-MSCs from fresh marrow aspirate in αMEM supplemented with 5% human platelet lysate using both an automated cell expansion system (Quantum, Terumo BCT) and a manual flask-based method using multilayer flasks. We compared MSCs expanded using both methods and assessed their differentiation to adipogenic and osteogenic tissue, capacity to suppress T-cell proliferation, cytokines, and growth factor secretion profile and cost-effectiveness of manufacturing enough BM-MSCs to administer a single dose of 100 × 106 cells per subject in a clinical trial of 100 subjects. RESULTS: We have established that large quantities of clinical-grade BM-MSCs manufactured with an automated hollow-fiber bioreactor were phenotypically (CD73, CD90, CD105) and functionally (adipogenic and osteogenic differentiation and cytokine and growth factor secretion) similar to manually expanded BM-MSCs. In addition, MSC manufacturing costs significantly less and required less time and effort when using the Quantum automated cell expansion system over the manual multilayer flasks method. CONCLUSION: MSCs manufactured by an automated bioreactor are physically and functionally equivalent to the MSCs manufactured by the manual flask method and have met the standards required for clinical application.

Modifiers of mesenchymal stem cell quantity and quality.

BACKGROUND: Clinical trials involving mesenchymal stem cell (MSC) therapy have variable outcomes. We hypothesize this is largely attributed to donor-to-donor variability and tissue of origin. STUDY DESIGN AND METHODS: We examined proliferation rates, cytokine secretion profiles, and differentiation capability of seven bone marrow-derived MSCs (BM-MSCs) and 16 adipose tissue-derived MSCs (AD-MSCs) from 23 donors. RESULTS: AD-MSCs had the capacity to undergo more than 40 population doublings, while the BM-MSC proliferation rate was found to be considerably slower. We observed more donor-to-donor variability in proliferation rates of BM-MSCs than with AD-MSCs. Cytokine analysis revealed that secretion of eight cytokines was significantly increased by AD-MSCs at Passage (P)3 compared with P1, while for BM-MSCs at P3 relative to P1, only interleukin-8 and RANTES secretion was significantly increased. By P5, secretion of all cytokines by AD-MSCs was either decreased or unchanged relative to P1. In contrast, cytokine secretion by BM-MSCs at P5 was mostly unchanged, although secretion of six cytokines was significantly increased relative to P1. When we compared cytokine secretion between AD-MSCs and BM-MSCs at P3, AD-MSCs significantly secreted higher concentrations of cytokines than BM-MSCs while the opposite was observed at P5. This suggests that BM-MSCs are relatively more potent at P5 while AD-MSCs are relatively more potent at P3. AD-MSCs and BM-MSCs exhibited the capacity for chondrogenic differentiation. AD-MSCs and BM-MSCs appeared to display a more enhanced inclination toward adipogenic and osteogenic differentiation, respectively. CONCLUSION: MSC physiology is significantly influenced by donor variability and tissue of origin and this should be considered when designing clinical trials.

A Systematic Review and Meta-analysis of Mesenchymal Stem Cell Injections for the Treatment of Perianal Crohn's Disease: Progress Made and Future Directions.

BACKGROUND: There has been a surge in clinical trials studying the safety and efficacy of mesenchymal stem cells for the treatment of perianal Crohn's disease. OBJECTIVE: The purpose of this work was to systematically review the literature to determine safety and efficacy of mesenchymal stem cells for the treatment of refractory perianal Crohn's disease. DATA SOURCES: Sources included PubMed, Cochrane Library Central Register of Controlled Trials, and Embase. STUDY SELECTION: Studies that reported safety and/or efficacy of mesenchymal stem cells for the treatment of perianal Crohn's disease were included. Two independent assessors reviewed eligible articles. INTERVENTION: The study intervention was delivery of mesenchymal stem cells to treat perianal Crohn's disease. MAIN OUTCOMES MEASURES: Safety and efficacy of mesenchymal stem cells used to treat perianal Crohn's disease were measured. RESULTS: Eleven studies met the inclusion criteria and were included in the systematic review. Three trials with a comparison arm were included in the meta-analysis. There were no significant increases in adverse events (OR = 1.07 (95% CI, 0.61-1.89); p = 0.81) or serious adverse events (OR = 0.53 (95% CI, 0.28-0.98); p = 0.04) in patients treated with mesenchymal stem cells. Mesenchymal stem cells were associated with improved healing as compared with control subjects at primary end points of 6 to 24 weeks (OR = 3.06 (95% CI, 1.05-8.90); p = 0.04) and 24 to 52 weeks (OR = 2.37 (95% CI, 0.90-6.25); p = 0.08). LIMITATIONS: The study was limited by its multiple centers and heterogeneity in the study inclusion criteria, mesenchymal stem cell origin, dose and frequency of delivery, use of scaffolding, and definition and time point of fistula healing. CONCLUSIONS: Although there have been only 3 trials conducted with control arms, existing data demonstrate improved efficacy and no increase in adverse or serious adverse events with mesenchymal stem cells as compared with control subjects for the treatment of perianal Crohn's disease.

Genetic modification of H2AX renders mesenchymal stromal cell-derived dopamine neurons more resistant to DNA damage and subsequent apoptosis.

BACKGROUND AIMS: Aberrant production of reactive oxygen species (ROS) and its impact on the integrity of genomic DNA have been considered one of the major risk factors for the loss of dopaminergic neurons in Parkinson's disease (PD). Stem cell transplantation as a strategy to replenish new functional neurons has great potential for PD treatment. However, limited survival of stem cells post-transplantation has always been an obstacle ascribed to the existence of neurotoxic environment in PD patients. METHODS: To improve the survival of transplanted stem cells for PD treatment, we explored a new strategy based on the function of the H2AX gene (H2A histone family, member X) in determination of DNA repair and cell apoptosis. We introduced a mutant form Y142F of H2AX into dopamine (DA) neuron-like cells differentiated from bone marrow-derived mesenchymal stromal cells (BMSCs). RESULTS: Expression of H2AX(Y142F) renders DA neuron-like cells more resistant to DNA damage and subsequent cell death induced by ultraviolet irradiation and 1-methyl-4-phenylpyridinium (MPP+) treatment. DISCUSSION: This is a meaningful attempt to improve the sustainability of BMSC-derived dopamine neurons under a brain neurotoxic environment. Further studies are needed to evaluate the implications of our findings in stem cell therapy for PD and related diseases.

Dual roles of autologous CD8+ T cells in hematopoietic progenitor cell mobilization and engraftment.

BACKGROUND: Poor marrow cellularity alone cannot explain poor hematopoietic progenitor cell (HPC) mobilization. This study assessed the role of CD8+ T cells in HPC cell mobilization and engraftment. STUDY DESIGN AND METHODS: Mobilization and engraftment were assessed in 192 autologous HPC donors. CD34+, CD4+, and CD8+ T-cell contents in apheresis products were evaluated. Using a chemotaxis assay, we assessed the effect of purified autologous CD8+ T cells from low and high mobilizers on HPC migration from high to low stromal cell-derived factor (SDF-1α) concentration gradients. We also assessed CD8+ T-cell content association with days to neutrophil engraftment. RESULTS: The median number of CD34+ cells/kg was 4.7 × 10(6) . Patients were categorized according to their total CD34+ cell collection quartile distribution into low, moderate, and high mobilizers. We found that HPC products from low mobilizers contained more CD8+ T cells than HPC products from moderate and high mobilizers. Chemotaxis assays showed depletion of CD8+ T cells enhances HPC mobilization independent of SDF-1α concentration. Neutrophil engraftment analysis showed that the higher the CD8+ T-cell content per unit CD34+ cell, the faster the rate of engraftment. CONCLUSION: Our findings suggest CD8+ T cells inhibit HPC mobilization and facilitate homing and engraftment.

Vitamin D effect on umbilical cord blood characteristics: a comparison between African Americans and Caucasians.

BACKGROUND: Umbilical cord blood (UCB) units collected from African Americans (AAs) have lower total nucleated cell (TNC) and CD34+ cell counts and are more likely to disqualify for banking compared to other ethnic groups. Furthermore, AAs have higher prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency. Given the importance of 25(OH)D in hematopoiesis, we examined the racial differences in UCB unit 25(OH)D content and its correlation with UCB cellular characteristics. STUDY DESIGN AND METHODS: A total of 119 UCB units that did not meet the TNC count banking criteria were analyzed. Fifty-one UCB units were collected from AA mothers and 68 from Caucasian mothers. We analyzed UCB volume, hematocrit (Hct), TNCs, mononuclear cells (MNCs), CD34+ cells, plasma 25(OH)D concentration, and progenitor clonogenic capacity measured by colony-forming cell (CFC) assay. RESULTS: Compared to Caucasians, AAs had significantly lower UCB 25(OH)D levels (p<0.0001), TNCs (p=0.002), MNCs (p=0.026), and CD34+ cells (p=0.026). Severe deficiency (25(OH)D<10 ng/mL) was only detected in AAs. No difference in median CFC count/10,000 MNCs was detected between AAs and Caucasians. Independent of race, a significant association was detected between 25(OH)D level and TNCs (r=0.193 p=0.035) and Hct (r=0.196 p=0.033). CONCLUSION: These results indicate the importance of 25(OH)D level as a racially independent predictor of UCB cellular characteristics and support further investigation of bioactive vitamin D and other predictors of hematopoiesis on cord blood quality.

Translation initiator EIF4G1 mutations in familial Parkinson disease.

Genome-wide analysis of a multi-incident family with autosomal-dominant parkinsonism has implicated a locus on chromosomal region 3q26-q28. Linkage and disease segregation is explained by a missense mutation c.3614G>A (p.Arg1205His) in eukaryotic translation initiation factor 4-gamma (EIF4G1). Subsequent sequence and genotype analysis identified EIF4G1 c.1505C>T (p.Ala502Val), c.2056G>T (p.Gly686Cys), c.3490A>C (p.Ser1164Arg), c.3589C>T (p.Arg1197Trp) and c.3614G>A (p.Arg1205His) substitutions in affected subjects with familial parkinsonism and idiopathic Lewy body disease but not in control subjects. Despite different countries of origin, persons with EIF4G1 c.1505C>T (p.Ala502Val) or c.3614G>A (p.Arg1205His) mutations appear to share haplotypes consistent with ancestral founders. eIF4G1 p.Ala502Val and p.Arg1205His disrupt eIF4E or eIF3e binding, although the wild-type protein does not, and render mutant cells more vulnerable to reactive oxidative species. EIF4G1 mutations implicate mRNA translation initiation in familial parkinsonism and highlight a convergent pathway for monogenic, toxin and perhaps virally-induced Parkinson disease.

Mechanism of mesenchymal stem cell-induced neuron recovery and anti-inflammation.

BACKGROUND AIMS: After ischemic or hemorrhagic stroke, neurons in the penumbra surrounding regions of irreversible injury are vulnerable to delayed but progressive damage as a result of ischemia and hemin-induced neurotoxicity. There is no effective treatment to rescue such dying neurons. Mesenchymal stem cells (MSCs) hold promise for rescue of these damaged neurons. In this study, we evaluated the efficacy and mechanism of MSC-induced neuro-regeneration and immune modulation. METHODS: Oxygen-glucose deprivation (OGD) was used in our study. M17 neuronal cells were subjected to OGD stress then followed by co-culture with MSCs. Rescue effects were evaluated using proliferation and apoptosis assays. Cytokine assay and quantitative polymerase chain reaction were used to explore the underlying mechanism. Antibody and small molecule blocking experiments were also performed to further understand the mechanism. RESULTS: We showed that M17 proliferation was significantly decreased and the rate of apoptosis increased after exposure to OGD. These effects could be alleviated via co-culture with MSCs. Tumor necrosis factor-α was found elevated after OGD stress and was back to normal levels after co-culture with MSCs. We believe these effects involve interleukin-6 and vascular endothelial growth factor signaling pathways. DISCUSSION: Our studies have shown that MSCs have anti-inflammatory properties and the capacity to rescue injured neurons.