Mitochondrial ROS direct the differentiation of murine pluripotent P19 cells

Natalia Pashkovskaia,Uta Gey,Gerhard Rödel

doi:10.1016/j.scr.2018.06.007

Abstract

ROS are frequently associated with deleterious effects caused by oxidative stress. Despite the harmful effects of non-specific oxidation, ROS also function as signal transduction molecules that regulate various biological processes, including stem cell proliferation and differentiation. Here we show that mitochondrial ROS level determines cell fate during differentiation of the pluripotent stem cell line P19. As stem cells in general, P19 cells are characterized by a low respiration activity, accompanied by a low level of ROS formation. Nevertheless, we found that P19 cells contain fully assembled mitochondrial electron transport chain supercomplexes (respirasomes), suggesting that low respiration activity may serve as a protective mechanism against ROS. Upon elevated mitochondrial ROS formation, the proliferative potential of P19 cells is decreased due to longer S phase of the cell cycle. Our data show that besides being harmful, mitochondrial ROS production regulates the differentiation potential of P19 cells: elevated mitochondrial ROS level favours trophoblast differentiation, whereas preventing neuron differentiation. Therefore, our results suggest that mitochondrial ROS level serves as an important factor that directs differentiation towards certain cell types while preventing others.

Highlights

Reactive oxygen species (ROS), products of one-electron reduction of molecular oxygen, possess a high oxidative potential and can cause severe damage in living cells
Like embryonic stem cells (ESCs), P19 cells differentiate in response to retinoic acid (RA) yielding various types of differentiated cells depending on growth conditions
Under a slightly modified differentiation protocol, P19 cells give rise to neuron-like cells (JonesVilleneuve et al, 1983). To induce this neuron differentiation, P19 cells in suspension were grown with RA to form 3D embryoid bodies (Fig. 1 c)

Summary

Introduction

Reactive oxygen species (ROS), products of one-electron reduction of molecular oxygen, possess a high oxidative potential and can cause severe damage in living cells. ROS generation in cells is tightly connected with the oxidative phosphorylation metabolic pathway (cellular respiration). During this process electrons flow through four mitochondrial electron transport chain (mETC) enzymatic complexes and two mobile carriers to the final acceptor – oxygen. This process releases energy that is used to form the proton gradient across the mitochondrial inner membrane to produce ATP (Mitchell and Yochim, 1968). METC is the most efficient energy production source and one of the main sources of ROS (Adam-Vizi and Chinopoulos, 2006; Bleier and Dröse, 2013)

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Results

Conclusion