Quantification and Immunophenotypic Characterization of Bone Marrow and Umbilical Cord Blood Mesenchymal Stem Cells by Multicolor Flow Cytometry

Osteoarthritis is a significant and costly cause of pain for both humans and horses. The horse has been identified as a suitable model for human osteoarthritis. Regenerative therapy with allogeneic mesenchymal stem cells (MSCs) is a promising treatment, but the safety of this procedure continues to be debated. The aim of this study is to evaluate the safety of intra-articular injections of allogeneic MSCs on healthy joints by comparing two different dosages and two different tissue sources, namely, bone marrow and umbilical cord blood, with a placebo treatment on the same individuals. We also assessed the influence of autologous versus allogeneic cells for bone marrow-derived MSC treatment. Twelve clinically sound horses were subjected to injections in their 4 fetlock joints. Each of the three fetlocks was administered a different MSC type, and the remaining fetlock was injected with phosphate-buffered saline as a control. Six horses received 10 million cells per joint, and the 6 other horses received 20 million cells per joint. Clinical and ultrasound monitoring revealed that allogeneic bone marrow-derived MSCs induced significantly more synovial effusion compared to umbilical cord blood-derived MSCs but no significant difference was noted within the synovial fluid parameters. The administration of 10 million cells in horses triggered significantly more inflammatory signs than the administration of 20 million cells. Mesenchymal stem cell injections induced mild to moderate local inflammatory signs compared to the placebo, with individual variability in the sensitivity to the same line of MSCs. Understanding the behavior of stem cells when injected alone is a step towards the safer use of new strategies in stem cell therapy, where the use of either MSC secretome or MSCs combined with biomaterials could enhance their viability and metabolic activity.

Download Full-text

Intra-bone marrow co-transplantation of umbilical cord mesenchymal stem cells promotes the engraftment of umbilical cord blood stem cells in iron overload NOD/SCID mice

10.21203/rs.3.rs-26543/v1 ◽

2020 ◽

Author(s):

Zhi Huang ◽

Yuhua Xiao ◽

Xiaomin Chen ◽

Huiping Li ◽

Jingyu Gao ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Iron Overload ◽

Cord Blood ◽

Umbilical Cord ◽

Umbilical Cord Blood ◽

Scid Mice ◽

Blood Stem Cells ◽

Cord Blood Stem Cells

Abstract Background: Iron overload aggravates the difficulty of umbilical cord blood stem cell engraftment and reduces the survival of patients undergoing hematopoietic stem cells (HSC) transplantation. Mesenchymal stem cells (MSC) have been implicated in playing a significant role in HSC engraftment. This study aimed to determine the effect of intra-bone marrow (IBM) co-transplantation of umbilical cord blood mononuclear cells (UCB-MNC) and mesenchymal stem cells (UC-MSC) on the engraftment and hematopoietic recovery in an iron overload hematopoietic microenvironment. Methods: 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 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 four groups for transplantation: (1) control group, (2) IBM MSC+ group: IBM injection of combined UCB-MNC/UC-MSC, (3) IBM group: IBM injection of only UCB-MNC, and (4) IV group: intravenous injection of UCB-MNC. Six weeks after transplantation, the human CD45 + cells in the bone marrow were analyzed by flow cytometry. The semi-quantitative analysis of vascular endothelial growth factor (VEGF-a), osteopontin (OPN), and stromal cell-derived factor-1a (SDF-1a) were examined by immunohistochemistry staining (IHC). Results: The survival rate and the percentages of human CD45 + cells in bone marrow were highest in the IBM MSC+ group with statistical significance. In addition, the levels of VEGF-a, OPN, and SDF-1a in bone marrow were all significantly higher in the IBM MSC+ group than the other groups. Conclusion: IBM co-transplantation of UC-MSC might improve the engraftment of UCB-MNC 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 umbilical cord blood stem cells in the bone marrow with iron overload.

Download Full-text