TY - JOUR
T1 - Cystine-dependent antiporters buffer against excess intracellular reactive sulfur species-induced stress
AU - Akiyama, Masahiro
AU - Unoki, Takamitsu
AU - Aoki, Hanako
AU - Nishimura, Akiyuki
AU - Shinkai, Yasuhiro
AU - Warabi, Eiji
AU - Nishiyama, Kazuhiro
AU - Furumoto, Yuka
AU - Anzai, Naohiko
AU - Akaike, Takaaki
AU - Nishida, Motohiro
AU - Kumagai, Yoshito
N1 - Funding Information:
We thank Prof. Masayuki Yamamoto (Tohoku University, Japan) for kind donation of Nrf2 KO mice. We thank Prof. Jon Fukuto (Sonoma State University, USA) for kind donation of CysSSSCys. This work was supported in part by JST CREST Grant Number JPMJCR2024 (20348438) to M.N. and JSPS KAKENHI Grant Number JP18H05293 to Y.K. We thank Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.
Funding Information:
We thank Prof. Masayuki Yamamoto (Tohoku University, Japan) for kind donation of Nrf2 KO mice. We thank Prof. Jon Fukuto (Sonoma State University, USA) for kind donation of CysSSSCys. This work was supported in part by JST CREST Grant Number JPMJCR2024 ( 20348438) to M.N. and JSPS KAKENHI Grant Number JP18H05293 to Y.K. We thank Edanz ( https://jp.edanz.com/ac ) for editing a draft of this manuscript.
Publisher Copyright:
© 2022 The Authors
PY - 2022/11
Y1 - 2022/11
N2 - Reactive sulfur species (RSS) play a role in redox homeostasis; however, adaptive cell responses to excessive intracellular RSS are not well understood. Therefore, in this study, we generated transgenic (Tg) mice overexpressing cystathionine gamma-lyase (CSE) to produce excessive RSS. Contrary to expectations, tissue concentrations of RSS, such as cysteine persulfide (CysSSH), were comparable in both wild-type and CSE Tg mice, but the plasma concentrations of CysSSH were significantly higher in CSE Tg mice than in wild-type mice. This export of surplus intracellular RSS was also observed in primary hepatocytes of CSE Tg mice. Exposure of primary hepatocytes to the RSS generator sodium tetrasulfide (Na2S4) resulted in an initial increase in the intracellular concentration of RSS, which later returned to basal levels after export into the extracellular space. Interestingly, among all amino acids, cystine (CysSSCys) was found to be essential for CysSSH export from primary mouse hepatocytes, HepG2 cells, and HEK293 cells during Na2S4 exposure, suggesting that the cystine/glutamate transporter (SLC7A11) contributes, at least partially, to CysSSH export. We established HepG2 cell lines with knockout and overexpression of SLC7A11 and used them to confirm SLC7A11 as the predominant antiporter of CysSSCys and CysSSH. We observed that the poor efflux of excess CysSSH from the cell enhanced cellular stresses induced by Na2S4 exposure, such as polysulfidation of intracellular proteins, mitochondrial damage, and cytotoxicity. These results suggest the presence of a cellular response to excess intracellular RSS that involves the extracellular efflux of excess CysSSH by a cystine-dependent transporter to maintain intracellular redox homeostasis.
AB - Reactive sulfur species (RSS) play a role in redox homeostasis; however, adaptive cell responses to excessive intracellular RSS are not well understood. Therefore, in this study, we generated transgenic (Tg) mice overexpressing cystathionine gamma-lyase (CSE) to produce excessive RSS. Contrary to expectations, tissue concentrations of RSS, such as cysteine persulfide (CysSSH), were comparable in both wild-type and CSE Tg mice, but the plasma concentrations of CysSSH were significantly higher in CSE Tg mice than in wild-type mice. This export of surplus intracellular RSS was also observed in primary hepatocytes of CSE Tg mice. Exposure of primary hepatocytes to the RSS generator sodium tetrasulfide (Na2S4) resulted in an initial increase in the intracellular concentration of RSS, which later returned to basal levels after export into the extracellular space. Interestingly, among all amino acids, cystine (CysSSCys) was found to be essential for CysSSH export from primary mouse hepatocytes, HepG2 cells, and HEK293 cells during Na2S4 exposure, suggesting that the cystine/glutamate transporter (SLC7A11) contributes, at least partially, to CysSSH export. We established HepG2 cell lines with knockout and overexpression of SLC7A11 and used them to confirm SLC7A11 as the predominant antiporter of CysSSCys and CysSSH. We observed that the poor efflux of excess CysSSH from the cell enhanced cellular stresses induced by Na2S4 exposure, such as polysulfidation of intracellular proteins, mitochondrial damage, and cytotoxicity. These results suggest the presence of a cellular response to excess intracellular RSS that involves the extracellular efflux of excess CysSSH by a cystine-dependent transporter to maintain intracellular redox homeostasis.
UR - http://www.scopus.com/inward/record.url?scp=85140398143&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85140398143&partnerID=8YFLogxK
U2 - 10.1016/j.redox.2022.102514
DO - 10.1016/j.redox.2022.102514
M3 - Article
C2 - 36279630
AN - SCOPUS:85140398143
VL - 57
JO - Redox Biology
JF - Redox Biology
SN - 2213-2317
M1 - 102514
ER -