- Browse by Subject
Browsing by Subject "HSC"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Bmi1 Regulates Wnt Signaling in Hematopoietic Stem and Progenitor Cells(Springer, 2021) Yu, Hao; Gao, Rui; Chen, Sisi; Liu, Xicheng; Wang, Qiang; Cai, Wenjie; Vemula, Sasidhar; Fahey, Aidan C.; Henley, Danielle; Kobayashi, Michihiro; Liu, Stephen Z.; Qian, Zhijian; Kapur, Reuben; Broxmeyer, Hal E.; Gao, Zhonghua; Xi, Rongwen; Liu, Yan; Pediatrics, School of MedicinePolycomb group protein Bmi1 is essential for hematopoietic stem cell (HSC) self-renewal and terminal differentiation. However, its target genes in hematopoietic stem and progenitor cells are largely unknown. We performed gene expression profiling assays and found that genes of the Wnt signaling pathway are significantly elevated in Bmi1 null hematopoietic stem and progenitor cells (HSPCs). Bmi1 is associated with several genes of the Wnt signaling pathway in hematopoietic cells. Further, we found that Bmi1 represses Wnt gene expression in HSPCs. Importantly, loss of β-catenin, which reduces Wnt activation, partially rescues the HSC self-renewal and differentiation defects seen in the Bmi1 null mice. Thus, we have identified Bmi1 as a novel regulator of Wnt signaling pathway in HSPCs. Given that Wnt signaling pathway plays an important role in hematopoiesis, our studies suggest that modulating Wnt signaling may hold potential for enhancing HSC self-renewal, thereby improving the outcomes of HSC transplantation.Item Characterization of the Cellular Output of a Point-of-Care Device and the Implications for Addressing Critical Limb Ischemia(Mary Ann Liebert, 2015) Woodell-May, Jennifer E.; Tan, Matthew L.; King, William J.; Swift, Matthew J.; Welch, Zachary R.; Murphy, Michael P.; McKale, James M.; Department of Surgery, IU School of MedicineCritical limb ischemia (CLI) is a terminal disease with high morbidity and healthcare costs due to limb loss. There are no effective medical therapies for patients with CLI to prevent amputation. Cell-based therapies are currently being investigated to address this unmet clinical need and have shown promising preliminary results. The purpose of this study was to characterize the output of a point-of-care cell separator (MarrowStim P.A.D. Kit), currently under investigation for the treatment of CLI, and compare its output with Ficoll-based separation. The outputs of the MarrowStim P.A.D. Kit and Ficoll separation were characterized using an automated hematology analyzer, colony-forming unit (CFU) assays, and tubulogenesis assays. Hematology analysis indicated that the MarrowStim P.A.D. Kit concentrated the total nucleated cells, mononuclear cells, and granulocytes compared with baseline bone marrow aspirate. Cells collected were positive for VEGFR-2, CD3, CD14, CD34, CD45, CD56, CD105, CD117, CD133, and Stro-1 antigen. CFU assays demonstrated that the MarrowStim P.A.D. Kit output a significantly greater number of mesenchymal stem cells and hematopoietic stem cells compared with cells output by Ficoll separation. There was no significant difference in the number of endothelial progenitor cells output by the two separation techniques. Isolated cells from both techniques formed interconnected nodes and microtubules in a three-dimensional cell culture assay. This information, along with data currently being collected in large-scale clinical trials, will help instruct how different cellular fractions may affect the outcomes for CLI patients.Item Progress towards improving homing and engraftment of hematopoietic stem cells for clinical transplantation(Wolters Kluwer, 2019-07) Huang, Xinxin; Broxmeyer, Hal E.; Microbiology and Immunology, School of MedicinePurpose of review Hematopoietic cell transplantation (HCT) is a life-saving treatment for a variety of hematological and nonhematological disorders. Successful clinical outcomes after transplantation rely on adequate hematopoietic stem cell (HSC) numbers, and the homing and subsequent short-term and long-term engraftment of these cells in the bone marrow. Enhancing the homing capability of HSCs has the potential for high impact on improving HCT and patient survival. Recent findings There are a number of ways to enhance HSC engraftment. Neutralizing negative epigenetic regulation by histone deacetylase 5 (HDAC5) increases surface CXCR4 expression and promotes human HSC homing and engraftment in immune-deficient NSG (NOD.Cg-Prkdcscid IL2rgtm1Wjl/Sz) mice. Short-term treatment of cells with glucocorticoids, pharmacological stabilization of hypoxia-inducible factor (HIF)-1α, increasing membrane lipid raft aggregation, and inhibition of dipeptidyl peptidase 4 (DPP4) facilitates HSC homing and engraftment. Added to these procedures, modulating the mitochondria permeability transition pore (MPTP) to mitigate ambient air-induced extra physiological oxygen stress/shock (EPHOSS) by hypoxic harvest and processing, or using cyclosporine A during air collection increases functional HSC numbers and improves HSC engraftment. Summary A better understanding of the regulation of human HSC homing mediated by various signaling pathways will facilitate development of more efficient means to enhance HCT efficacy.