Investigation of The Expression Levels of Peroxiredoxins in Small Intestinal Tissue From Pediatric Celiac Patients and The Relationship of Peroxiredoxins with Hypoxia Inducible Factor-1 Alpha (HIF-1?)
Project no. 545 · Status: Kapanmış · 2016
Summary
Celiac disease (CD) is an autoimmune enteropathy generating as a result of intolerance against gluten protein. After determining that oxidative stress is one of the important mechanisms in the pathogenesis of CD, studies on antioxidant defense systems have gained importance. Peroxiredoxins(PRDXs) are a multifunctional antioxidant enzyme family which has recently been discovered. Six isoforms of PRDX (PRDX1-6) are expressed in mammalian. In addition to antioxidant functions, these enzymes have been found to be related with significant cellular pathways such as cell survival, apoptosis and inflammation. Recent studies have shown that PRDX plays an important role in a variety of inflammatory diseases. However, the role of PRDXs in the pathogenesis of CD is not yet known. In this study, it was aimed to investigate the expression of PRDX (1-6) isoforms in the small intestine of CD patients and the possible relationship between hypoxia-induced factor-1? (HIF-1?) transcription factor. For this purpose, the expression levels of PRDX enzymes and HIF-1? in duodenal biopsy specimens of pediatric CD patients were determined by real-time PCR and immunoblotting techniques. After, the impact of HIF-1? gene silencing on the expression of PRDX enzymes was examined in Caco-2 cell by siRNA method. The mRNA expressions of PRDX-1, PRDX-2 and PRDX-4 in CD patients were significantly lower than the control group; while PRDX-5 and HIF-1? were found to be significantly higher than the control group. There was no significant difference between the two groups in terms of PRDX-3 and PRDX-6 mRNA expression levels. However, PRDX-4 protein expression level was determined significantly lower in the CD group, but PRDX-5 expression was founed significantly higher compared to the control group. No significant change was detected in other prdx isoforms. On the other hand, in the cell culture studies, the silencing of the HIF-1? in Caco-2 cells under normoxic and hypoxic conditions caused significant changes in the expressions of PRDX-2 and -5, but did not cause any changes in the expressions of PRDX-1 and -4. These findings indicated that PRDXs, especially PRDX-5, may play an important role in the pathogenesis of CD. Furthermore, our results suggest that the PRDX-2 and -5 may be target genes for HIF-1? transcription factor.