| 1. |
|
|
| 2. |
- Bertini, R, et al.
(författare)
-
Thioredoxin, a redox enzyme released in infection and inflammation, is a unique chemoattractant for neutrophils, monocytes, and T cells
- 1999
-
Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 189:11, s. 1783-1789
-
Tidskriftsartikel (refereegranskat)abstract
- Thioredoxin (Trx) is a ubiquitous intracellular protein disulfide oxidoreductase with a CXXC active site that can be released by various cell types upon activation. We show here that Trx is chemotactic for monocytes, polymorphonuclear leukocytes, and T lymphocytes, both in vitro in the standard micro Boyden chamber migration assay and in vivo in the mouse air pouch model. The potency of the chemotactic action of Trx for all leukocyte populations is in the nanomolar range, comparable with that of known chemokines. However, Trx does not increase intracellular Ca2+ and its activity is not inhibited by pertussis toxin. Thus, the chemotactic action of Trx differs from that of known chemokines in that it is G protein independent. Mutation of the active site cysteines resulted in loss of chemotactic activity, suggesting that the latter is mediated by the enzyme activity of Trx. Trx also accounted for part of the chemotactic activity released by human T lymphotropic virus (HTLV)-1–infected cells, which was inhibited by incubation with anti-Trx antibody. Since Trx production is induced by oxidants, it represents a link between oxidative stress and inflammation that is of particular interest because circulating Trx levels are elevated in inflammatory diseases and HIV infection.
|
|
| 3. |
- Sasada, T., et al.
(författare)
-
Possible involvement of thioredoxin reductase as well as thioredoxin in cellular sensitivity to cis-diamminedichloroplatinum (II)
- 1999
-
Ingår i: Free Radical Biology & Medicine. - : Elsevier. - 0891-5849 .- 1873-4596. ; 27:5-6, s. 504-514
-
Tidskriftsartikel (refereegranskat)abstract
- The thioredoxin (TRX) system, composed of nicotinamide adenine dinucleotide phosphate (reduced form), TRX, and TRX reductase (TRXR), has multiple biologic functions via thiol-mediated redox control. In this study, we investigated the relationship between intracellular TRXR levels and cellular sensitivity to cis-diamminedichloroplatinum (II) (CDDP). HeLa, a human cervical carcinoma cell line, cultured with CDDP showed a time- and dose-dependent reduction of intracellular TRXR activity, which was well correlated with the decrease in cell viability after exposure to CDDP. In a cell-free system, CDDP was found to directly inactivate the reduced form of purified human TRXR. The CDDP-resistant variants of HeLa cells, established by continuous exposure to CDDP, exhibited an increased expression and activity of TRXR as well as TRX compared with the parental cells. In addition, sodium selenate, an inhibitor of TRXR, was found to increase the susceptibility to CDDP in the CDDP-resistant cells. Moreover, the HeLa cells transfected with an antisense TRXR RNA expression vector to reduce the intracellular enzyme activity displayed an enhanced sensitivity to CDDP. Taken together with previous reports on TRX, these results indicate the possible involvement of TRXR as well as TRX in the cellular sensitivity and resistance to CDDP.
|
|
