Bone Marrow Mesenchymal Cells: How Do They Contribute to Tissue Repair and Are They Really Stem Cells?

Abstract

Adult stem cells typically generate the cell types of the tissue in which they reside, and thus the range of their differentiation is considered limited. Bone marrow mesenchymal stem cells (MSCs) are different from other somatic stem cells in that they differentiate not only into the same mesodermal-lineage such as bone, cartilage, and adipocytes but also into other lineages of ectodermal and endodermal cells. Thus, MSCs are a unique type of adult stem cells. In addition, MSCs home to damaged sites, differentiate into cells specific to the tissue and contribute to tissue repair. Therefore, application of MSCs in the treatment of various diseases, including liver dysfunction, myocardial infarction, and central nervous system repair, has been initiated. Because MSCs are generally harvested as adherent cells from bone marrow aspirates, however, they comprise heterogeneous cell populations and their wide-ranging differentiation ability and repair functions are not yet clear. Recent evidence suggests that a very small subpopulation of cells that assume a repair function with the ability to differentiate into trilineage cells resides among human MSCs and effective utilization of such cells is expected to improve the repair effect of MSCs. This review summarizes recent advances in the clarification of MSC properties and discusses future perspectives.

Autologous mesenchymal stem cell–derived dopaminergic neurons function in parkinsonian macaques

“…We further tested whether this degenerative process would affect all grafted cells. The plateau of the 1-hit model was significantly higher than the baseline (before engraftment) 11 CFT binding level (baseline BP ND = 0.087 ± 0.028 vs. BP ND at plateau = 0.17 ± 0.029; Welch's corrected T 13 = 2.04, 1-tailed P < 0.05), suggesting that a small portion of the grafted MSC-DP cells survive and integrate for more than 7 months. This is in contrast to findings in naive MSCs engrafted into rodents, which showed a plateau of the reduction curve returned to the baseline (Supplemental Figure 2), indicating that all naive MSCs may eventually degenerate when transplanted into brain.…”

“…This is in contrast to findings in naive MSCs engrafted into rodents, which showed a plateau of the reduction curve returned to the baseline (Supplemental Figure 2), indicating that all naive MSCs may eventually degenerate when transplanted into brain. We also estimated how the dopamine-releasing capacity (DArc) of grafts related to 11 C-CFT binding after engraftment ( Figure 3F). The dopamine-releasing capacity was calculated by multiplication of dopamine release by K + concentration (pM per 10 6 cells) in vitro, as measured by HPLC, and the total number of cells engrafted in each animal (10 6 cells).…”

“…The MSCs have been already tested for cell therapy in PD model rodents (7)(8)(9) and even in patients with PD (10). However, they have shown poor performance for restoration of motor function, potentially due to limited spontaneous differentiation (11) or facilitated apoptosis (12,13) of MSCs. Recent studies of fetal midbrain graft have suggested that better outcomes could be obtained if the graft consisted of well-differentiated A9 dopaminergic neurons (14)(15)(16), the most severely damaged neuronal type in PD (17).…”

Immunological effect induced by mesenchymal stem cells in a rat liver transplantation model

“…The pathway is very significant in alleviating transplant immune rejection (40)(41)(42)(43). Thereby, it was necessary to determine the homing ability of MSCs to the graft liver in group C. Currently, there are a variety of methods to determine the homing ability.…”

Paracrine effect of bone marrow mesenchymal stem cells on proliferation, apoptosis, and alpha-actin-2 expression in hepatic stellate cells

“…Some scientists think that the rate of MSC colonization in the liver is low, with very few MSCs transforming into functional cells (Anjos-Afonso et al, 2004;Kuroda et al, 2011). The therapeutic benefits of the treatment have been attributed to the paracrine effects of MSCs (van Poll et al, 2008;Nagaishi et al, 2014).…”