The metabolic function of hepatocytes differentiated from human mesenchymal stem cells is inversely related to cellular glutathione levels

Abstract

Differentiation of mesenchymal stem cells (MSCs) to hepatocytes-like cells is associated with alteration in the level of reactive oxygen species (ROS) and antioxidant defense system. Here, we report the role of glutathione in the functions of hepatocytes derived from MSCs. The stem cells undergoing differentiation were treated with glutathione modifiers [buthionine sulfoxide (BSO) or N-acetyl cysteine (NAC)], and hepatocytes were collected on day 14 of differentiation and analysed for their biological and metabolic functions. Differentiation process has been performed in presence of glutathione modifiers viz. BSO and NAC. Depending on the level of cellular glutathione, the proliferation rate of MSCs was affected. Glutathione depletion by BSO resulted in increased levels of albumin and ROS in hepatocytes. Whereas, albumin and ROS were inhibited in cells treated with glutathione precursor (NAC). The metabolic function of hepatocytes was elevated in BSO-treated cells as judged by increased urea, transferrin, albumin, alanine transaminase and aspartate transaminase secretions in the media. However, the metabolic activity of the hepatocytes was inhibited when glutathione was increased by NAC. We conclude that the efficiency of metabolic function of hepatocytes is inversely related to the levels of cellular glutathione. These data may suggest a novel role of glutathione in regulation of metabolic function of hepatocytes.

Antioxidant and reactive oxygen species scavenging properties of cellular albumin in HepG2 cells is mediated by the glutathione redox system

“…The hepatoprotective role of NAC via glutathione synthesis has also been approved in vivo against toxicants . This finding is in agreement with our studies showing that hepatocytes differentiation from MSCs in the presence of NAC, can protect the cells against oxidative damage factors .…”

The role of albumin and PPAR‐α in differentiation‐dependent change of fatty acid profile during differentiation of mesenchymal stem cells to hepatocyte‐like cells

“…There are evidences which show that the biosynthesis of albumin, which is often used as a marker of hepatocyte formation during stem cells differentiation, is linked to several metabolic processes of the liver cells. Recently, we reported the role of albumin in biochemical and metabolic functions of hepatocytes differentiated from stem cells . The part played by albumin in balancing saturated fatty acids and PUSFAs in differentiated hepatocytes could be partly because of its role in fatty acid uptake by cells and further incorporation into phospholipids or its binding capacity to a wide range of fatty acids, including several known PPARs activators …”

“…Recently, we reported the role of albumin in biochemical and metabolic functions of hepatocytes differentiated from stem cells. 29 The part played by albumin in balancing saturated fatty acids and PUSFAs in differentiated hepatocytes could be partly because of its role in fatty acid uptake by cells and further incorporation into phospholipids 30 or its binding capacity to a wide range of fatty acids, including several known PPARs activators. 31 Based on the data on time-course changes in PPAR-α expression and other liver markers during the hepatocyte differentiation, it is likely that the overexpression of PPAR-α as a regulator of fatty acid synthesis is an early change in response to differentiation process.…”

Regulation of the mitochondrial reactive oxygen species: Strategies to control mesenchymal stem cell fates ex vivo and in vivo

“…As a strong antioxidant, NAC preserves MSC activities, including high self‐renewal, multipotency, a low apoptosis rate and strong cell adhesion capacity, by preventing activation of Wnt/ β ‐catenin signalling and excessive cellular ROS production . Buthionine sulfoxide significantly increases albumin and ROS levels in hepatogenic MSCs, whereas NAC inhibits these related metabolic functions . However, NAC has also been demonstrated to inhibit adipocyte differentiation and to maintain the osteogenic differentiation capacity of MSCs by decreasing ROS levels .…”