In addition, we explored the possible association between p53 and proteins involved in rate of metabolism and functioning of thiamine such as THTR1 and thiamine-dependent enzymes: the pyruvate dehydrogenase E1 component subunit beta (PDHB), oxoglutarate dehydrogenase (OGDH) and transketolase (TK). Results and Discussion Effect of thiamine antagonists within the state of p53 protein in neuronal SH-SY5Y cells p53 is recognized as a key coordinator of cellular events triggered by oxidative stress often associated with abnormalities in thiamine-dependent processes18. activation of p53 DNA-binding activity. Phosphorylation of p53 at Ser20 was equally efficient in upregulation of thiamine transporter 1 (THTR1) by all antagonists. However, induction of the expressions of the pyruvate dehydrogenase E1 component subunit beta (PDHB) and oxoglutarate dehydrogenase (OGDH) required dual phosphorylation of p53 at Ser9 and Ser20, seen in cells treated with PT and OT. Moreover, pretreatment of the cells having a decoy oligonucleotide transporting wild-type p53-response element markedly attenuated OT-induced THTR1, PDHB and OGDH gene manifestation suggesting an important part of p53 in transactivation of these genes. Finally, analysis of gene Talniflumate and metabolic networks showed that OT causes cell apoptosis through the p53-dependent intrinsic pathway. Intro A large number of studies have shown that nerve cells are the most susceptible to a disturbance in thiamine homeostasis1. Swelling, gliosis and variations in oxidative rate of metabolism often accociated with reductions in thiamine linked processes result in DNA damage and neuronal cells death, which are thought to be the basis for many neurodegenerative diseases2, 3. It is identified that cells sustaining the higher level of DNA damage result in activation of transcriptional element p53 via post-translational modifications that provides the opportunities for apoptotic transmission amplification4. However, evidences also suggest that p53 may be involved in DNA restoration via preventing the replication of damaged DNA and activation of the manifestation of genes important for the protection of the cell from oxidative damage and molecules that are essential to thiamine homeostasis. Therefore, it was demonstrated that p53 causes transactivation of thiamine transporter 1 (THTR-1) gene manifestation leading to an increase in thiamine uptake. Accumulated thiamine and its active form – thiamine pyrophosphate (TPP) are further implicated in bad feedback mechanisms that suppress intracellular p53 activity5, 6. This is Oaz1 especially important for the alleviation of the deleterious effects of mitochondrial dysfunction and permitting cells temporarily caught in growth reenter to the cell cycle. While growing body of evidence suggests a critical function of p53 in thiamine homeostasis, the part of p53 inside a coordination of cellular events induced by Talniflumate changes in thiamine rate of metabolism are not completely elucidated. It is identified that thiamine antagonists – amprolium (AM), oxythiamine (OT) and pyrithiamine (PT) metabolically interfere with thiamine metabolism and its functions7. All antagonists competitively inhibit thiamine transport while PT was found to be more efficient8. OT and PT, as competitive substrates of thiamine pyrophosphokinase (TPK), can restrict the level of TPP and at the same time become pyrophosphorylated (PP) by TPK. Moreover, relating to current evidence, PT-PP could efficiently block Talniflumate TPK while OT-PP could Talniflumate compete with TPP coenzyme function and inhibit TPP-dependent enzymes leading to an impairment in thiamine homeostasis7, 9C12. We previously showed that culturing of rat Personal computer-12 and human being SH-SY5Y cell lines differentiated into neurons13, 14 in the presence of 10?M thiamine and different concentrations of PT, OT and AM dramatically decreased the cell viability in time and dose-dependent manner, triggered DNA fragmentation and resulted in stimulation of apoptosis via Caspase 3 – mediated signaling pathway. Notably, the cells appeared to be mostly vulnerable to PT and OT with the less degree to AM. This observation suggested that cells with neuronal phenotype treated with AM were still able to retain a low intracellular concentration of thiamine and undergo death slower than after treatment with OT or PT13, 14. In the current study, we prompted to identify the effects of thiamine antagonists AM, Talniflumate OT and PT on the level of p53 gene manifestation, its post-translational changes, DNA-binding activity and its part in the rules of metabolic and signaling pathways using RA-differentiated SH-SY5Y cells which are a widely-used model of human being neurons. The recent studies showed that RA-differentiated SH-SY5Y cells show a greater activation of.