Imaging Redox State Heterogeneity Within Individual Embryonic Stem Cell Colonies

Abstract

Redox state mediates embryonic stem cell (ESC) differentiation and thus offers an important complementary approach to understanding the pluripotency of stem cells. NADH redox ratio (NADH/(Fp + NADH)), where NADH is the reduced form of nicotinamide adenine dinucleotide and Fp is the oxidized flavoproteins, has been established as a sensitive indicator of mitochondrial redox state. In this paper, we report our redox imaging data on the mitochondrial redox state of mouse ESC (mESC) colonies and the implications thereof. The low-temperature NADH/Fp redox scanner was employed to image mESC colonies grown on a feeder layer of gamma-irradiated mouse embryonic fibroblasts (MEFs) on glass cover slips. The result showed significant heterogeneity in the mitochondrial redox state within individual mESC colonies (size: ~200–440 μm), exhibiting a core with a more reduced state than the periphery. This more reduced state positively correlates with the expression pattern of Oct4, a well-established marker of pluripotency. Our observation is the first to show the heterogeneity in the mitochondrial redox state within a mESC colony, suggesting that mitochondrial redox state should be further investigated as a potential new biomarker for the stemness of embryonic stem cells.

Citation analysis of the scientific publications of Britton Chance in ISI citation indexes

“…That was on average two papers per three week at the age of 74 74 and a metabolometer 75 for monitoring human nutritional status. Chance worked on research till the last few days of his life.…”

Imaging mitochondrial redox potential and its possible link to tumor metastatic potential

“…Redox scanning has been extensively employed to study mitochondrial metabolism and redox state in normal tissues and diseases (Barlow et al 1979; Mayevsky et al 1983; Haselgrove et al 1990; Kitai et al 1992; Sato et al 1995; Shiino et al 1999; Ramanujam et al 2001; Zhang et al 2004a; Xu et al 2010; Xu et al 2011a; Xu et al 2011b; Xu et al 2011c). The redox ratio Fp/NADH of freeze-trapped liver mitochondria was shown to correlate with the oxidation-reduction state modulated by the β-hydroxybutyrate/acetoacetate couple (Chance et al 1979).…”