Thioredoxin is an oxidoreductase enzyme of 12,000 daltons, containing a dithiol-disulfide active site.
It is ubiquitous and found in many organisms from plants and bacteria to mammals. Multiple in vitro
substrates for thioredoxin have been identified, including ribonuclease, choriogonadotropins,
coagulation factors, glucocorticoid receptor, and insulin. Reduction of insulin is classically used as an
activity test.
NCBI Summary:
The protein encoded by this gene acts as a homodimer and is involved in many redox reactions. The encoded protein is active in the reversible S-nitrosylation of cysteines in certain proteins, which is part of the response to intracellular nitric oxide. This protein is found in the cytoplasm. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011]
Thioredoxin, an antioxidant redox protein, in ovarian follicles of women undergoing in vitro fertilization. Kishi I et al. (2015) Oxidative stress has a bidirectional role in the development and maturation of zygotes and embryos. Reduction-oxidation reactions and regulatory proteins, such as thioredoxin (TRX) and thioredoxin reductase (TRXR), are intimately involved in the regulation of oxidative stress. The aim of this study was to determine the levels of TRX mRNA and protein in ovarian follicles collected from women undergoing in vitro fertilization (IVF) and to assess these levels relative to follicle size, presence of oocytes, and responsiveness to superovulation. Follicular fluid (FF) and/or granulosa cells (GCs) from large and small follicles were collected at the time of ovum pick-up from 42 IVF patients enrolled in this study. We divided the patients into normal and poor responders (NR and PR, respectively) based on the serum estradiol levels on the day of human chorionic gonadotropin (hCG) administration. We also compared the TRX concentration in FF (FF-TRX) between oocyte-containing follicles (Oc+) and empty follicles (Oc-). The transcript levels of TRX, but not TRXR, were significantly higher in GCs derived from follicles collected from NR than PR, as determined by semi-quantitative RT-PCR analysis. In NR, the FF-TRX was significantly higher in Oc+ follicles than in Oc- follicles and also in large Oc+ follicles than in large Oc- follicles. Unlike NR, PR exhibited no positive association with elevated FF-TRX and presence of oocytes. Based on its collective anti-oxidative, cytoprotective, and cytokine-like properties of TRX, TRX is likely to be involved in the optimal growth and maturation of ovarian follicles and responsiveness to hyperstimulation.////////////////// Osborne LJ, et al reported the expression and localisation of thioredoxin in mouse
reproductive tissues during the oestrous cycle.
Thioredoxin expression within the reproductive tissues of the female
mouse was analysed during the oestrous cycle stages of dioestrus,
oestrus and metoestrus. Localisation of thioredoxin within the reproductive
organs of the mouse during the oestrous cycle has shown that the
expression of thioredoxin is specific for distinct areas within the
reproductive organs. These areas are the stratified squamous epithelium
of the vagina, the simple columnar epithelium and the uterine glands of the
uterus, the ciliated columnar epithelium of the oviduct, the corpus lutea,
the interstitial cells and the secondary follicles of the ovary.