Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Experimental Center, Guangdong Cord Blood Bank, Guangzhou, China.
Transplant Cell Ther. 2021 Mar;27(3):230.e1-230.e7. doi: 10.1016/j.jtct.2020.12.003. Epub 2020 Dec 14.
Iron overload aggravates the difficulty of umbilical cord blood (UCB) stem cell engraftment and reduces the survival of patients undergoing hematopoietic stem cell (HSC) transplantation. Mesenchymal stem cells (MSCs) have been suggested to have a significant role in HSC engraftment. This study aimed to determine the effect of intra-bone marrow (IBM) and i.v. cotransplantation of UBC mononuclear cells (MNCs) and umbilical cord (UC) MSCs on engraftment and hematopoietic recovery in an iron overload hematopoietic microenvironment. The iron overload model was established by dose-escalation intraperitoneal injection of iron dextran in NOD/SCID mice. Iron deposition in the bone marrow, heart, and liver was examined using hematoxylin and eosin (H&E) staining. Serum levels of ferritin and iron status in the liver were measured. The iron overload NOD/SCID mice were sublethally irradiated and divided into 5 groups for transplantation: (1) control group; (2) IBM+ group: IBM injection of combined UCB-MNCs/UC-MSCs; (3) IV+ group: i.v. injection of combined UCB-MNCs/UC-MSCs; (4) IBM group: IBM injection of only UCB-MNCs; and (5) IV group: i.v. injection of UCB-MNCs. At 6 weeks after transplantation, the human CD45 cells in the bone marrow were analyzed by flow cytometry. The semiquantitative analysis of vascular endothelial growth factor (VEGF-A), osteopontin (OPN), and stromal cell-derived factor-1a (SDF-1a) were examined by immunohistochemical staining (IHC). Compared with the IBM and IV groups, the survival rate and the percentages of human CD45 cells and CD34 cells and colony-forming units (CFU) in bone marrow were elevated in the IBM+ and IV+ groups. In addition, the levels of VEGF-A, OPN, and SDF-1a in bone marrow were all higher in the IBM+ and IV+ groups. Our data show that IBM and i.v. cotransplantation of UC-MSCs can improve the engraftment and proliferation of UCB-MNCs in iron overload NOD/SCID mice. The increased expression of VEGF-A, OPN, and SDF-1a in the bone marrow may be involved in improving the hematopoietic microenvironment and promoting the implantation of human UCB stem cells in the bone marrow with iron overload.
铁过载加重了脐带血（UCB）干细胞植入的难度，并降低了接受造血干细胞（HSC）移植的患者的存活率。间充质干细胞（MSCs）已被证明在 HSC 植入中具有重要作用。本研究旨在确定骨髓内（IBM）和静脉内（i.v.）共输注 UBC 单核细胞（MNCs）和脐带（UC）MSCs 对铁过载造血微环境中植入和造血恢复的影响。通过递增剂量腹腔内注射右旋糖酐铁在 NOD/SCID 小鼠中建立铁过载模型。用苏木精和伊红（H&E）染色检查骨髓、心脏和肝脏中的铁沉积。测量血清铁蛋白水平和肝脏铁状态。将铁过载 NOD/SCID 小鼠亚致死性照射，并分为 5 组进行移植：（1）对照组；（2）IBM+组：IBM 注射联合 UCB-MNCs/UC-MSCs；（3）IV+组：静脉注射联合 UCB-MNCs/UC-MSCs；（4）IBM 组：IBM 注射仅 UCB-MNCs；（5）IV 组：静脉注射 UCB-MNCs。移植后 6 周，通过流式细胞术分析骨髓中的人 CD45 细胞。通过免疫组织化学染色（IHC）检测血管内皮生长因子（VEGF-A）、骨桥蛋白（OPN）和基质细胞衍生因子-1a（SDF-1a）的半定量分析。与 IBM 和 IV 组相比，IBM+和 IV+组的骨髓中人 CD45 细胞和 CD34 细胞以及集落形成单位（CFU）的存活率和百分比均升高。此外，IBM+和 IV+组骨髓中的 VEGF-A、OPN 和 SDF-1a 水平均升高。我们的数据表明，IBM 和静脉内共输注 UC-MSCs 可以改善铁过载 NOD/SCID 小鼠中 UCB-MNCs 的植入和增殖。骨髓中 VEGF-A、OPN 和 SDF-1a 的表达增加可能参与改善造血微环境，促进铁过载骨髓中人类 UCB 干细胞的植入。
