Effects of N-acetyl-l-cysteine on target sites of hydroxylated fullerene-induced cytotoxicity in isolated rat hepatocytes

Abstract

The effects of N-acetyl-L-cysteine (NAC) on cytotoxicity caused by a hydroxylated fullerene [C60(OH)24], which is known a nanomaterial and/or a water-soluble fullerene derivative, were studied in freshly isolated rat hepatocytes. The exposure of hepatocytes to C60(OH)24 at a concentration of 0.1 mM caused time (0-3 h)-dependent cell death accompanied by the formation of cell blebs, loss of cellular ATP, and reduced glutathione (GSH) and protein thiol levels, as well as the accumulation of glutathione disulfide and malondialdehyde (MDA), indicating lipid peroxidation. Despite this, C60(OH)24-induced cytotoxicity was effectively prevented by NAC pretreatment ranging in concentrations from 1 to 5 mM. Further, the loss of mitochondrial membrane potential (MMP) and generation of oxygen radical species in hepatocytes incubated with C60(OH)24 were inhibited by pretreatment with NAC, which caused increases in cellular and/or mitochondrial levels of GSH, accompanied by increased levels of cysteine via enzymatic deacetylation of NAC. On the other hand, severe depletion of cellular GSH levels caused by diethyl maleate at a concentration of 1.25 mM led to the enhancement of C60(OH)24-induced cell death accompanied by a rapid loss of ATP. Taken collectively, these results indicate that pretreatment with NAC ameliorates (a) mitochondrial dysfunction linked to the depletion of ATP, MMP, and mitochondrial GSH level and (b) induction of oxidative stress assessed by reactive oxygen species generation, losses of intracellular GSH and protein thiol levels, and MDA formation caused by C60(OH)24, suggesting that the onset of toxic effects is at least partially attributable to a thiol redox-state imbalance as well as mitochondrial dysfunction related to oxidative phosphorylation.

Cytotoxic effects of thioxanthone derivatives as photoinitiators on isolated rat hepatocytes

“…It is well known that intracellular GSH works as a free radical scavenger, which protects cells against ROS, and that the accumulation of proteins with irreversible thiol oxidation is a parameter of ROS-induced cellular damage (Kettenhofen & Wood, 2010). It was reported that the mitochondrial sulfhydryl group was also a critical target site for chemical compounds in rat hepatocytes (Calabrese, Morgan, & Riemer, 2017;Chernyak & Bernardi, 1996;Nakagawa et al, 2014). Previous studies showed that the oxidation of GSH to GSSG caused the formation of mixed disulfides between GSSG and cellular protein thiols and that a factor in their formation is related to the concentration of intracellular GSSG (Fawthrop, Boobis, & Davies, 1991;Nakagawa, Moldéus, & Cotgreave, 1992;Reed, 1990), suggesting that a slight loss of protein thiols caused by DETX may be dependent on the formation of mixed disulfides ( Figure 4).…”

“…On the other hand, rat hepatocytes were preincubated with NAC at a concentration of 5.0 mM for 15 minutes before the addition of photoinitiators. The concentrations of NAC and fructose used in this study were referred to the ranges in previous studies (Cannon, Harvison, & Rush, 1991;Nakagawa et al, 2014;Nakagawa, Suzuki, & Inomata, 2018). Corresponding control groups received an equivalent volume of DMSO.…”

“…Previous studies showed that the oxidation of GSH to GSSG caused the formation of mixed disulfides between GSSG and cellular protein thiols and that a factor in their formation is related to the concentration of intracellular GSSG (Fawthrop, Boobis, & Davies, 1991;Nakagawa, Moldéus, & Cotgreave, 1992;Reed, 1990), suggesting that a slight loss of protein thiols caused by DETX may be dependent on the formation of mixed disulfides ( Figure 4). It was reported that the mitochondrial sulfhydryl group was also a critical target site for chemical compounds in rat hepatocytes (Calabrese, Morgan, & Riemer, 2017;Chernyak & Bernardi, 1996;Nakagawa et al, 2014).…”

Potential Links between Cytoskeletal Disturbances and Electroneurophysiological Dysfunctions Induced in the Central Nervous System by Inorganic Nanoparticles

“…Mitochondria are the major sources of intracellular energy (i.e., ATP), which is necessary for sustaining the structural integrity and proper function of the cytoskeleton because each actin molecule is bound to an ATP or ADP molecule. Multiple studies have suggested that inorganic NPs can affect intracellular ATP synthesis by disrupting mitochondrial function [62,63]. The conformational changes of the cytoskeleton are dependent on ATP, as well as motor proteins, such as myosin, dynein and kinesin, which move along MFs and MTs by interacting with actin and tubulin; the process utilizes energy obtained from ATP hydrolysis.…”

Preparation of hydrophilic C60(OH)10/2-hydroxypropyl-β-cyclodextrin nanoparticles for the treatment of a liver injury induced by an overdose of acetaminophen

“…Although fullerenols are more soluble than unmodified C 60 , further enhancement in their solubility is necessary for a precise evaluation of their biological activities and for extensive biomedical applications. In addition, some researchers have reported that fullerenol shows cytotoxic effects that are dependent on the number of hydroxyl groups contained by the molecule [15,16]. Therefore using fullerenol with a minimum number of hydroxyl groups would be a desirable approach for pharmaceutical applications of fullerenol.…”