Explore the vast range of titles available.

Background This phase II randomized controlled trial tested whether the intracarotid arterial administration (ICAA) of autologous CD34 + cells to patients within 14 ± 7 days after acute ischemic stroke (IS) could be safe and further improve short- and long-term outcomes. Methods Between January 2018 and March 2022, 28 consecutive patients were equally randomly allocated to the cell-treated group (CD34 + cells/3.0 × 10 7 /patient) or the control group (receiving optimal medical therapy). CD34 + cells were transfused into the ipsilateral brain infarct zone of cell-treated patients via the ICAA in the catheterization room. Results The results demonstrated 100% safety and success rates for the procedure, and no long-term tumorigenesis was observed in cell-treated patients. In cell-treated patients, the angiogenesis capacity of circulating endothelial progenitor cells (EPCs)/Matrigel was significantly greater after treatment than before treatment with granulocyte colony-stimulating factor (all p  < 0.001). Blood samples from the right internal jugular vein of the cell-treated patients presented significantly greater levels of the stromal cell-derived factor 1α/EPC at 5, 10 and 30 min compared with 0 min (all p  < 0.005). The National Institute of Health Stroke Scale scores were similar upon presentation, but a greater response was observed by Days 30 and 90 in the cell-treated group than in the control group. Tc-99 m brain perfusion was significantly greater at 180 days in the cell-treated group than in the control group ( p  = 0.046). The combined long-term end points (defined as death/recurrent stroke/or severe disability) were notably lower in the control group compared with the cell-treated group (14.3% vs. 50.0%, p  = 0.103). Conclusion Intracarotid transfusion of autologous CD34 + cells is safe and might improve long-term outcomes in patients with acute IS. Trial registration ISRCTN, ISRCTN15677760. Registered 23 April 2018- Retrospectively registered, https://doi.org/10.1186/ISRCTN15677760

Background Because of limitations of transportation imposed by the COVID-19 pandemic, current recommendation calls for cryopreservation of allogeneic stem cell transplants before patient conditioning. A single cell therapy laboratory was selected to function as the central cryopreservation hub for all European registry donor transplants intended for the Australian-Pacific region. We examined properties of these transplants to ascertain how quality is maintained. Methods We analyzed 100 pandemic-related allogeneic mobilized blood-derived stem cell apheresis products generated at 30 collection sites throughout Europe, shipped to and cryopreserved at our center between April and November of 2020. Products were shipped in the cool, subsequently frozen with DMSO as cryoprotectant. Irrespective of origin, all products were frozen within the prescribed shelf-life of 72 h. Results Prior to cryopreservation, viable stem cell and leukocyte count according to the collection site and our reference laboratory were highly concordant (r 2  = 0.96 and 0.93, respectively) and viability was > 90% in all instances. Median nominal post-thaw recovery of viable CD34+ cells was 42%. Weakly associated with poorer CD34+ cell recovery was higher leukocyte concentration, but not time lag between apheresis or addition of cryopreservant, respectively, and start of freezing. The correlation between pre- and post-thaw CD34+ cell dose was high (r 2  = 0.85), hence predictable. Neutrophil and platelet engraftment were prompt with no evidence of dose dependency within the range of administered cell doses (1.31–15.56 × 10 6 CD34+ cells/kg). Conclusions General cryopreservation of allogeneic stem cell transplants is feasible. While more than half of the CD34+ cell content is lost, the remaining stem cells ensure timely engraftment.

Background We previously demonstrated that CD34 + cell transplantation in animals healed intractable fractures via osteogenesis and vasculogenesis; we also demonstrated the safety and efficacy of this cell therapy in an earlier phase I/II clinical trial conducted on seven patients with fracture nonunion. Herein, we present the results of a phase III clinical trial conducted to confirm the results of the previous phase studies using a larger cohort of patients. Methods CD34 + cells were mobilized via administration of granulocyte colony-stimulating factor, harvested using leukapheresis, and isolated using magnetic cell sorting. Autologous CD34 + cells were transplanted in 15 patients with tibia nonunion and 10 patients with femur nonunion, who were followed up for 52 weeks post transplantation. The main outcome was a reduction in time to heal the tibia in nonunion patients compared with that in historical control patients. We calculated the required number of patients as 15 based on the results of the phase I/II study. An independent data monitoring committee performed the radiographic assessments. Adverse events and medical device failures were recorded. Results All fractures healed during the study period. The time to radiological fracture healing was 2.8 times shorter in patients with CD34 + cell transplantation than in the historical control group (hazard ratio: 2.81 and 95% confidence interval 1.16–6.85); moreover, no safety concerns were observed. Conclusions Our findings strongly suggest that autologous CD34 + cell transplantation is a novel treatment option for fracture nonunion. Trial registration UMIN-CTR, UMIN000022814. Registered on 22 June 2016.

Background Healthy volunteer registry donors have become the backbone of stem cell transplantation programs. While most registrants will never become actual donors, a small minority are called upon twice, most commonly for the same patient because of poor graft function. Anecdotal evidence provides no hard reasons to disallow second-time mobilized apheresis, but few centers have treated enough two-time donors for definitive conclusions. Moreover, for reasons unknown, the efficiency of G-CSF varies greatly between donations. Methods Comparison of outcomes of first vs. second donations can formally confirm G-CSF responsiveness as intrinsically, likely genetically, determined. In our database, we identified 60 donors (1.3%) who received two cycles of G-CSF 24 days to 4 years apart and systematically compared mobilization outcomes. Results First and second mobilization and collection proceeded without severe or unusual adverse effects. First-time mobilization efficiency was highly predictive of second-time mobilization. Neither mobilization efficiency nor time lag between donations affected the similarity of first- and second-time mobilization outcomes. Conclusions With the caveat that only donors with an unremarkable first donation were cleared for a second, our data indicate that a second donation is feasible, equally tolerable as a first donation, and efficient. Moreover, the data strongly support the notion of donor-intrinsic variables dictating mobilization response and argue against relevant damage to the stem cell compartment during mobilization with rhG-CSF.

Molecular therapies and functional studies greatly benefit from spatial and temporal precision of genetic intervention. We therefore conceived and explored tag-activated microRNA (miRNA)-mediated endogene deactivation (TAMED) as a research tool and potential lineage-specific therapy. For proof of principle, we aimed to deactivate γ-globin repressor BCL11A in erythroid cells by tagging the 3′ untranslated region (UTR) of BCL11A with miRNA recognition sites (MRSs) for the abundant erythromiR miR-451a. To this end, we employed nucleofection of CRISPR/Cas9 ribonucleoprotein (RNP) particles alongside double- or single-stranded oligodeoxynucleotides for, respectively, non-homologous-end-joining (NHEJ)- or homology-directed-repair (HDR)-mediated MRS insertion. NHEJ-based tagging was imprecise and inefficient (≤6%) and uniformly produced knock-in- and indel-containing MRS tags, whereas HDR-based tagging was more efficient (≤18%), but toxic for longer donors encoding concatenated and thus potentially more efficient MRS tags. Isolation of clones for robust HEK293T cells tagged with a homozygous quadruple MRS resulted in 25% spontaneous reduction in BCL11A and up to 36% reduction after transfection with an miR-451a mimic. Isolation of clones for human umbilical cord blood-derived erythroid progenitor-2 (HUDEP-2) cells tagged with single or double MRS allowed detection of albeit weak γ-globin induction. Our study demonstrates suitability of TAMED for physiologically relevant modulation of gene expression and its unsuitability for therapeutic application in its current form.

The study of soft, amorphous fascia has been constrained by definitional ambiguities regarding its fine structure, constituent and precise function. Here, a previously unrecognized CD34 + membranous cell (CMC) population was identified by single-cell RNA sequencing, which displayed a distinct spatial distribution in UMAP coordinates in the subcutaneous fascia of rat abdominal midline. Constituting one of the predominant cell populations in the fascia, CMCs were further validated morphologically in situ and in vitro. They exhibited lamina shapes and distributed alternating with the collagen bundles. Equipped with mechanosensors (integrins, cadherins, PIEZOs), CMCs are intricately interwoven with matrix fibers, forming the tensile mechanical apparatuses in the fascia. Enriched with Cx43 + gap junctions, Cdh1 + adherens junctions, integrin β1 + focal adhesions, Tsg101 + extracellular vesicles, F-actin + cytoskeletons, and caveolae, CMCs with marginal process foaming possessed typical evidence of signal conversion and transduction. The extensive membrane architecture of CMCs easily enabled their interactions with nerves, blood vessels, immune cells and interstitial fluid, promoting the integrations among different systems. In addition, functioning as membranous boundaries and signaling hubs, sheeting-like CMCs incompletely encapsulated or separated some structures, creating unique microenvironments. Molecular function analyses aligned with the ultrastructural features, distinguishing CMCs from other flat cells like fibroblasts. This discovery highlights a previously overlooked cell subpopulation, advancing our understanding of the fascial biology.

Fetal CD34+ cells enter the maternal circulation during pregnancy and may persist for decades. These cells are usually depicted as hematopoietic stem/progenitor cells. Our objective was to further determine the phenotype of fetal chimeric CD34+ cells in placental maternal blood from the intervillous space (IVS). Human healthy term placentas were analyzed (n=9). All fetuses were male. CD34+ cells were identified in the IVS and further characterized as fetal or maternal using X and Y chromosome fluorescence in situ hybridization. The phenotype of fetal cells was further analyzed using anti-CD117 (c-kit), anti-CD133, anti-CD31, anti-von Willebrand factor (vWF), anti-vimentin, anti-CD45 and anti-cytokeratin (CK) antibodies. We used preeclamptic placentas of male (n=3) and healthy placentas of female fetuses (n=3) as controls. As expected fetal cells were easily identified in the IVS and significantly increased in cases of preeclampsia. Most CD34+ cells in the IVS were of fetal origin (90%) and were not surrounded by CK staining further showing that they were not in fetal trophoblastic villi. Similarly, about 40% of CD31+ and 6% of vimentin+ cells in the IVS were fetal in origin. No CD117+ or CD133+ fetal cells were found in the IVS of examined placentas. Besides, all the CD34+ cells identified in the IVS were co-labeled with vWF or CD31, suggesting their endothelial origin. These results suggest that most CD34+ cells in maternal placental blood at term are fetal in origin from endothelial and not hematopoietic lineages.

Background CD34 + cells have been used to treat the patients with heart failure, but the outcome is variable. It is of great significance to scrutinize the fate and the mechanism of CD34 + cell differentiation in vivo during heart failure and explore its intervention strategy. Methods We performed single-cell RNA sequencing (scRNA-seq) of the total non-cardiomyocytes and enriched Cd34-tdTomato + lineage cells in the murine (male Cd34-CreERT2; Rosa26-tdTomato mice) pressure overload model (transverse aortic constriction, TAC), and total non-cardiomyocytes from human adult hearts. Then, in order to determine the origin of CD34 + cell that plays a role in myocardial fibrosis, bone marrow transplantation model was performed. Furthermore, to further clarify the role of CD34 + cells in myocardial remodeling in response to TAC injury, we generated Cd34-CreERT2; Rosa26-eGFP-DTA (Cre/DTA) mice. Results By analyzing the transcriptomes of 59,505 single cells from the mouse heart and 22,537 single cells from the human heart, we illustrated the dynamics of cell landscape during the progression of heart hypertrophy, including CD34 + cells, fibroblasts, endothelial and immune cells. By combining genetic lineage tracing and bone marrow transplantation models, we demonstrated that non-bone-marrow-derived CD34 + cells give rise to fibroblasts and endothelial cells, while bone-marrow-derived CD34 + cell turned into immune cells only in response to pressure overload. Interestingly, partial depletion of CD34 + cells alleviated the severity of myocardial fibrosis with a significant improvement of cardiac function in Cd34-CreERT2; Rosa26-eGFP-DTA model. Similar changes of non-cardiomyocyte composition and cellular heterogeneity of heart failure were also observed in human patient with heart failure. Furthermore, immunostaining showed a double labeling of CD34 and fibroblast markers in human heart tissue. Mechanistically, our single-cell pseudotime analysis of scRNA-seq data and in vitro cell culture study revealed that Wnt-β-catenin and TGFβ1/Smad pathways are critical in regulating CD34 + cell differentiation toward fibroblasts. Conclusions Our study provides a cellular landscape of CD34 + cell-derived cells in the hypertrophy heart of human and animal models, indicating that non-bone-marrow-derived CD34 + cells differentiating into fibroblasts largely account for cardiac fibrosis. These findings may provide novel insights for the pathogenesis of cardiac fibrosis and have further potential therapeutic implications for the heart failure.

Stem cell transplantation is nearly available for clinical application in the treatment of ischaemic heart disease (IHD), where it may be joined traditional methods (intervention and surgery). The angiogenic ability of seed cells is essential for this applicability. The aim of this study was to reveal the presence of CD34+ angiogenic stem cells in human decidua at the first trimester and to use their strong angiogenic capacity in the treatment of IHD. In vitro, human decidual CD34+ (dCD34+) cells from the first trimester have strong proliferation and clonality abilities. After ruling out the possibility that they were vascular endothelial cells and mesenchymal stem cells (MSCs), dCD34+ cells were found to be able to form tube structures after differentiation. Their angiogenic capacity was obviously superior to that of bone marrow mesenchymal stem cells (BMSCs). At the same time, these cells had immunogenicity similar to that of BMSCs. Following induction of myocardial infarction (MI) in adult rats, infarct size decreased and cardiac function was significantly enhanced after dCD34+ cell transplantation. The survival rate of cells increased, and more neovasculature was found following dCD34+ cell transplantation. Therefore, this study confirms the existence of CD34+ stem cells with strong angiogenic ability in human decidua from the first trimester, which can provide a new option for cell‐based therapies for ischaemic diseases, especially IHD.