Novel crosstalk between Vps26a and Nox4 signaling during neurogenesis

Abstract

Despite numerous studies on the molecular switches governing the conversion of stemness to differentiation in embryonic stem cells (ESCs), little is known about the involvement of the retromer complex. Under neural differentiation conditions, Vps26a deficiency (Vps26a-/-) or knockdown suppressed the loss of stemness and subsequent neurogenesis from ESCs or embryonic carcinoma cells, respectively, as evidenced by the long-lasting expression of stemness markers and the slow appearance of neuronal differentiation markers. Interestingly, relatively low reactive oxygen species (ROS) levels were generated during differentiation of Vps26a-/- ESCs, and treatment with an antioxidant or inhibitor of NADPH oxidase (Nox), a family of ROS-generating enzymes, led to restoration of stemness in wild-type cells to the level of Vps26a-/- cells during neurogenesis. Importantly, a novel interaction between Vps26a and Nox4 linked to the activation of ERK1/2 depended highly on ROS levels during neurogenesis, which were strongly suppressed in differentiating Vps26a-/- ESCs. Moreover, inhibition of phosphorylated ERK1/2 (pERK1/2) resulted in decreased ROS and Nox4 levels, indicating the mutual dependency between pERK1/2 and Nox4-derived ROS during neurogenesis. These results suggest that Vps26a regulates stemness by actively cooperating with the Nox4/ROS/ERK1/2 cascade during neurogenesis. Our findings have important implications for understanding the regulation of stemness via crosstalk between the retromer molecule and redox signaling, and may contribute to the development of ESC-based therapeutic strategies for the mass production of target cells.

On the Clinical Pharmacology of Reactive Oxygen Species

“…Therefore, NOX4 is constitutively active to preferentially produce H 2 O 2 , as opposed to all other NOXs, which produce superoxide. NOX4 plays a crucial role in cell differentiation, e.g., in preadipocytes and endothelial cells for angiogenesis (Schröder et al, 2009), as well as in neural precursor cells for hippocampal neurogenesis and memory formation (Choi et al, 2019;Yoshikawa et al, 2019). NOX5 is physiologically expressed in endothelium, spermatocytes, and lymphoid organs (Jagnandan et al, 2007).…”

NOX Inhibitors: From Bench to Naxibs to Bedside

“…However, knocking out the NOX4 gene in mice and rats does not result in an obvious phenotype or affect the life span of the animals (Kleinschnitz et al 2010;Rezende et al 2017). NOX4 enhances hormone-stimulated sodium and water transport in the kidney (Feraille et al 2014;Lu et al 2016), adipocytes differentiation (Schroder et al 2009), insulin sensitivity in the liver and adipose tissue (Mahadev et al 2004;Taniguchi et al 2006), glucosestimulated insulin secretion (Plecita-Hlavata et al 2020), autophagy in cardiomyocytes (Kouroku et al 2007), hippocampal neurogenesis, memory formation (Choi et al 2019;Yoshikawa et al 2019), angiogenesis, and vasodilation (Burgoyne et al 2007;Drummond et al 2000). NOX4 also activates downstream redox-sensitive proteins that play important roles in cell proliferation, migration, and apoptosis (Guo and Chen 2015).…”

Diet-dependent gut microbiota impacts on adult neurogenesis through mitochondrial stress modulation

“…Increased levels of ROS have also been associated with modulation of redox signalling pathways, including mitogen-activated protein kinase (MAPK) cascades and, specifically, extracellular signal-related protein kinase1/2 (ERK1/2) ( Zhang et al , 2016 ; Choi et al , 2019 ). In addition, several studies have already correlated the repression of ERK1/2 pathway with stem cell differentiation ( Na et al , 2010 ).…”