DuOx2 promoter regulation by hormones, transcriptional factors and the coactivator TAZ

The production of H2O2, which is essential to thyroid hormone synthesis, involves two NADPH oxidases: dual oxidases 1 and 2 (DuOx1 and DuOx2). A functional study with human DuOx genes and their 5'-flanking regions showed that DuOx1 and -2 promoters are different from thyroid-specific gene promoters. Furthermore, their transcriptional activities are not restricted to thyroid cells. While regulation of Tg (thyroglobulin) and TPO (thyroperoxidase) expression have been extensively studied, DuOx2 promoter regulation by hormones and transcriptional factors need to be more explored. Herein we investigated the role of TSH, insulin and insulin-like growth factor 1 (IGF-1), as well as the cAMP effect on DuOx2 promoter (ptx41) activity in transfected rat thyroid cell lines (PCCL3). We also assessed DuOx2 promoter activity in the presence of transcriptional factors crucial to thyroid development such as TTF-1 (thyroid transcription factor 1), PAX8, CREB, DREAM, Nkx2.5 and the coactivator TAZ in HeLa and HEK 293T-transfected cells. Our results show that TSH and forskolin, which increase cAMP in thyroid cells, stimulated DuOx2 promoter activity. IGF-1 led to pronounced stimulation, while insulin induction was not statistically different from DuOx2 promoter basal activity. All transcriptional factors selected for this work and coactivator TAZ, except DREAM, stimulated DuOx2 promoter activity. Moreover, Nkx2.5 and TAZ synergistically increased DuOx2 promoter activity. In conclusion, we show that DuOx2 expression is regulated by hormones and transcription factors involved in thyroid organogenesis and carcinogenesis, reinforcing the importance of the control of H2O2 generation in the thyroid.Peer reviewe

Supplementary Material for: DuOx2 Promoter Regulation by Hormones, Transcriptional Factors and the Coactivator TAZ

The production of H₂O₂, which is essential to thyroid hormone synthesis, involves two NADPH oxidases: dual oxidases 1 and 2 (DuOx1 and DuOx2). A functional study with human DuOx genes and their 5′-flanking regions showed that DuOx1 and -2 promoters are different from thyroid-specific gene promoters. Furthermore, their transcriptional activities are not restricted to thyroid cells. While regulation of Tg (thyroglobulin) and TPO (thyroperoxidase) expression have been extensively studied, DuOx2 promoter regulation by hormones and transcriptional factors need to be more explored. Herein we investigated the role of TSH, insulin and insulin-like growth factor 1 (IGF-1), as well as the cAMP effect on DuOx2 promoter (ptx41) activity in transfected rat thyroid cell lines (PCCL3). We also assessed DuOx2 promoter activity in the presence of transcriptional factors crucial to thyroid development such as TTF-1 (thyroid transcription factor 1), PAX8, CREB, DREAM, Nkx2.5 and the coactivator TAZ in HeLa and HEK 293T-transfected cells. Our results show that TSH and forskolin, which increase cAMP in thyroid cells, stimulated DuOx2 promoter activity. IGF-1 led to pronounced stimulation, while insulin induction was not statistically different from DuOx2 promoter basal activity. All transcriptional factors selected for this work and coactivator TAZ, except DREAM, stimulated DuOx2 promoter activity. Moreover, Nkx2.5 and TAZ synergistically increased DuOx2 promoter activity. In conclusion, we show that DuOx2 expression is regulated by hormones and transcription factors involved in thyroid organogenesis and carcinogenesis, reinforcing the importance of the control of H₂O₂ generation in the thyroid

Saccharomyces cerevisiae como probiótico para alevinos de tilápia-do-nilo submetidos a desafio sanitário Saccharomyces cerevisiae as probiotic for Nile tilapia fingerlings submitted to a sanitary challenge

Este experimento foi realizado com o objetivo de avaliar a utilização de levedura Saccharomyces cerevisiae (SC) como probiótico em rações para alevinos de tilápia-do-nilo (Oreochromis niloticus) submetidos a desafio sanitário. Foram utilizados 60 alevinos com 30 dias de idade, pesando 0,45 &plusmn; 0,02 g e medindo 3,10 &plusmn; 0,14 cm, distribuídos em delineamento completamente casualizado com dois tratamentos e seis repetições em 12 aquários de 50 L. Como desafio sanitário, cada aquário recebeu diariamente, durante o período experimental, o equivalente a 0,5 mL de esterco suíno in natura. Os tratamentos consistiram de uma ração com (0,1% SC) e sem probiótico. Ao final do experimento, os alevinos foram contados, medidos e pesados. Foram também retirados e pesados os intestinos de dois alevinos de cada tratamento, escolhidos aleatoriamente. O conteúdo dos intestinos foi submetido à contagem do número de bactérias e coliformes totais presentes. O desempenho e a sobrevivência não foram influenciados pela inclusão de SC na dieta. A SC colonizou o intestino dos alevinos alimentados com a dieta com SC e não foi encontrada naqueles alimentados com a dieta sem probiótico. Não foram observadas diferenças no número de bactérias e coliformes totais por grama de conteúdo intestinal e por mL de água dos aquários. A utilização de Saccharomyces cerevisiae como probiótico em rações para alevinos de tilápia-do-nilo (Oreochromis niloticus) promoveu a colonização no intestino dos peixes, entretanto, não influenciou o desempenho produtivo e a sobrevivência em sistema de cultivo com desafio sanitário.<br>The present experiment was carried with the objective to evaluate the Saccharomyces cerevisiae (SC) as probiotic in rations for Nile tilapia (Oreochromis niloticus) fingerlings submitted to a sanitary challenge. A total of 60 fingerlings with 30 days old, weighing 0.45 &plusmn; 0.02 g and 3.10 &plusmn; 0.14 cm were distributed to a completely randomized design with two treatments and six replications in 12 aquariums of 50 L. As a sanitary challenged each aquarium daily received, during the experimental period, an equivalent of 0.5 mL fresh swine manure. The treatments consisted of a ration with (0.1% SC) or without probiotic. At the end of the experiment the fingerlings were counted, measured and weighed. The intestines from two fingerlings randomly chosen were also removed and weighed per each treatment. Content of the intestines was submitted to a counting of the number of total bacteria and total coliformes presents. Performance and survival was not influenced by the inclusion of SC in the diet. The SC colonized the intestine of fingerlings fed with SC diet and was not observed in that fed with diets without probiotic. No differences were observed for the number of bacteria and total coliformes per g of intestinal content and per mL of water of the aquariums. The use of Saccharomyces cerevisiae as probiotic in rations of fingerlings of Nile tilapia (Oreochromis niloticus) promoted the colonization of the intestine of the fishes, however, no influenced the productive performance and survival in a culture system with sanitary challenge