The cross-talk between ROS and p38MAPKα in the Ex Vivo expanded human umbilical cord blood CD133+ cells

Abstract

This study investigated the correlation between and compared the effects of reactive oxygen species (ROS) and p38 mitogen-activated protein kinase α (p38MAPKα) in the ex vivo expanded umbilical cord blood (hUCB) CD133(+) cells. hUCB CD133(+) cells were cultured in the hematopoietic stem cells (HSCs) culture medium with N-acetylcysteine (NAC, an anti-oxidant), p38MAPKα-specific inhibitor (SB203580) or their combination. The levels of ROS and expression of phosphorylated p38MAPKα (p-p38) in CD133(+) cells were flow cytometrically detected. The efficacy of ex vivo expansion was evaluated by the density of CD133(+) cell sub-group colony-forming cells (CFC) and cobblestone area-forming cells (CAFC) assay. Our results showed decreased ROS levels in NAC, SB203580, and their combination treatment groups were almost 37%, 48%, and 85%, respectively. Furthermore, SB203580 abrogated the activation of p38MAPKα more obviously than NAC. Moreover, the CD133(+) cells in SB203580 treatment group had a 21.93±1.36-fold increase, and 14.50±1.19-fold increase in NAC treatment group, but only 10.13±0.57-fold increase in control group. In addition, SB203580 treatment led a higher level increase in the number of CFU and CAFC than NAC did. These findings suggested that, in expanded CD133(+) cells, ROS activates p38MAPKα, which, in turn, induces ROS production, and p38MAPKα might be the most suitable regulator in ROS-p38MAPKα pathway for the promotion of HSCs ex vivo expansion.

Baicalin potentiates TRAIL-induced apoptosis through p38 MAPK activation and intracellular reactive oxygen species production

“…Consistently, our previous study demonstrated that wogonin, another important component of S. baicalensis Georgi, activates ROS to promote TRAIL-induced apoptosis (13). It is also known that the activation of p38 is often mediated by ROS (19)(20)(21)(22). However, the results of the present study revealed that baicalin and TRAIL-induced activation of p38 is independent of ROS.…”

Inhibition of p38 MAPK activity promotes ex vivo expansion of human cord blood hematopoietic stem cells

“…The activation is likely attributable to oxidative stress resulting from culture of hUCB HSCs in vitro in a normoxic condition (20% of O 2 ) [15, 16]. This suggestion is supported by the findings from a separate study which was published recently by our group [38]. In that study, we found that hUCB CD133 + cells exhibited a significant increase in ROS production and p38 activation after ex vivo expansion.…”

NOX4 is the main NADPH oxidase involved in the early stages of hematopoietic differentiation from human induced pluripotent stem cells

“…We suspect that the low oxygen environment of the tumor may have contributed to the development of CD34 + cells with a low redox status that could explain a higher ability to engraft. In addition, a lot of efforts are actually made in order to maintain or restore the stemness of HSPCs by the use of NOXs inhibitors, antioxidants molecules and hypoxic culture, alone or in combination (22,72,(88)(89)(90)(91). Indeed, one limit of the hematopoietic differentiation protocol used in this study is that experiments were conducted under 21% oxygen, and not in hypoxia conditions like HSCs located in a hypoxia niche inside the bone marrow.…”