- 作者：C. Alicia Padilla Peñ ; a ; Raú ; l Gonzá ; lez ; Marí ; a J. Ló ; pez-Grueso ; J. Antonio Bá ; rcena
- 刊名：Redox Biology
- 出版年：2015
- 出版时间：August 2015
- 年：2015
- 卷：5
- 期：Complete
- 页码：418
- 全文大小：45 K
Aims
To ascertain whether Trx and/or Grx systems intermediate the anti-proliferative effect of NO on hepatoblastoma cells by modulating the redox-state of key proteins.
Methods
HepG2 cells overexpressing Nitric Oxide Synthase-3 (NOS-3) were transfected with specific siRNA to silence Trx1 and Grx1. The expression and thiolic redox state of proteins were determined by Western blot and redox mobility shift assay.
Results
Overexpression of NOS3 increased the levels and activities of proteins of the redoxin systems, Trx1, Grx1, TrxR1 and TxnIP, and the levels of signaling proteins (Akt1, pAkt1-Ser473, MapK, pMapK, Stat3, Fas). The thiolic redox state of Trx1, Grx1 and Akt1 shifted to more oxidized. Increases were also observed in Pro-apoptotic Caspase-3 fragment levels; caspase 3, 8 and 9 activities; antiapoptotic (Bcl-2); mitochondrial energetic (Aco2) and heme (Urod) metabolism; Glycolysis (Pkm2); and pentose phosphate pathway (Tkt). However, two cytosolic proteins related to iron (Aco1) and one carbon (Mat2) metabolism decreased markedly. Moreover, the redox state of Urod and Aco1 shifted to more oxidized cysteines.
Trx1 or Grx1 silencing augmented Tyr nitration and diminished cell proliferation in WT cells, but attenuated the antiproliferative effect on NO, the increase of Fas, Akt1 and pAkt1-Ser473 and the oxidative modification of Akt1 in NOS3 cells.
Conclusions
Trx1 and Grx1 exert contradictory influences on HepG2 cells. They are required for proliferation but they also contribute to antiproliferative effect of NO, associated to Akt1 redox changes.