Reconstrução de redes regulatórias gênicas em células de Sertoli humanas expostas ao 2,3,7,8-Tetraclorodibenzo-p-dioxina (TCDD)
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Data
2017-07-28
Autores
Ribeiro, Mariana Antunes [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A fertilidade masculina e a espermatogênese estão diretamente ligadas à capacidade das células de Sertoli em produzir fatores associados ao desenvolvimento das células germinativas. As células de Sertoli expressam receptores para FSH e testosterona e são os principais reguladores da espermatogênese. Aproximadamente 60-70% dos casos de infertilidade masculina são considerados idiopáticos, devido aos mecanismos moleculares envolvidos na espermatogênese ainda serem desconhecidos. Estudos recentes relatam que os microRNAs (miRNAs), são capazes de modular a função testicular durante a espermatogênese e sua expressão alterada pode estar envolvida na infertilidade masculina. miRNAs podem desempenhar papel importante na resposta aos xenobióticos que têm todas as consequências adversas para a saúde. Um grupo importante de compostos orgânicos com potencial tóxico são as dioxinas, como o 2,3,7,8-tetraclorodibenzo-p-dioxina (TCDD). Modelos experimentais de exposição ao TCDD, em camundongos, demonstraram que sua exposição provoca baixa contagem de espermatozóides e atraso na puberdade. Neste estudo, analisamos o efeito do TCDD nas células de Sertoli humanas in vitro após 72h a uma dose de 10nM. Nossos resultados mostraram que as enzimas antioxidantes catalase, superóxido dismutase e glutationa peroxidase diminuíram sua atividade e confirmaram o estresse oxidativo causado pelo TCDD nesse tipo celular. 78 miRNAs apresentaram expressão alterada, com regulação positiva de 73 e regulação negativa de 5 miRNAs quando comparados ao grupo controle. Com relação ao perfil de expressão gênica, 51 genes se apresentaram desregulados, dos quais 46 com regulação positiva e 5 genes com regulação negativa. Três tRNAsr egularam sua expressão negativamente devido a exposição ao TCDD. Além disso, 30 piRNAs se mostraram desregulados, 17 com regulação positiva e 13 com regulação negativa ao comparar os grupos. 7 diferentes famílias matriz de sítios de ligação de fatores de trancrição apresentaram expressão diferencial estatisticamente significante nas células de Sertoli após exposição ao TCDD. Várias vias se mostraram alteradas por ação do agente tóxico. Além disso, nosso estudo mostrou um baixo número de genes similares entre os mais expressos entre humanos, ratos e camundongoso que reflete a fisiologia de cada espécie e alerta sobre o cuidado ao utilizar modelos animais como substitutos para a exposição humana.
Male fertility and spermatogenesis are directly linked to the ability of Sertoli cells to produce factors associated with the development of germ cells. Sertoli cells express receptors for FSH and testosterone, and are the major regulators of spermatogenesis. Approximately 60-70% of male infertility cases are considered idiopathic, due to the molecular mechanisms involved in spermatogenesis are still unknown. Recent studies report that microRNAs (miRNAs) are capable of modulating spermatogenesis in testicular function and its altered expression may be involved in male infertility. miRNAs may play a role in response to xenobiotics that have all the adverse consequences for health. An important group of organic compounds that are potentially toxic are the dioxins such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Experimental models of exposure to TCDD in mice showed that its exposure causes low sperm count and delayed puberty. In this study, we analyzed the effect of TCDD on human Sertoli cells after a exposure of 72h in vitro at a dose of 10nM. Our results showed that the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase decreased their activity and confirmed the oxidative stress caused by TCDD in this cell type. 78 miRNAs showed altered expression with upregulation of 73 miRNAs and downregulation of 5 miRNAs compared to the control group. Regarding the gene expression profile, 51 genes showed deregulated, of which 46 genes with upregulation and downregulation of 5 genes. Three tRNAs were downregulated due to exposure to TCDD. Furthermore, 30 piRNAs proved deregulated, 17 piRNAs with upregulation and 13 with downregulation when comparing the groups. 7 different matrix families of transcription factor binding sites showed statistically significant expression in Sertoli cells after exposure to TCDD. Several pathways have been altered by the action of the toxic agent. Furthermore, our study showed a low number of similar genes among the most expressed among humans, rats and mice, which reflects the physiology of each species and alerts the caution when using animal models as substitutes for human exposure.
Male fertility and spermatogenesis are directly linked to the ability of Sertoli cells to produce factors associated with the development of germ cells. Sertoli cells express receptors for FSH and testosterone, and are the major regulators of spermatogenesis. Approximately 60-70% of male infertility cases are considered idiopathic, due to the molecular mechanisms involved in spermatogenesis are still unknown. Recent studies report that microRNAs (miRNAs) are capable of modulating spermatogenesis in testicular function and its altered expression may be involved in male infertility. miRNAs may play a role in response to xenobiotics that have all the adverse consequences for health. An important group of organic compounds that are potentially toxic are the dioxins such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Experimental models of exposure to TCDD in mice showed that its exposure causes low sperm count and delayed puberty. In this study, we analyzed the effect of TCDD on human Sertoli cells after a exposure of 72h in vitro at a dose of 10nM. Our results showed that the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase decreased their activity and confirmed the oxidative stress caused by TCDD in this cell type. 78 miRNAs showed altered expression with upregulation of 73 miRNAs and downregulation of 5 miRNAs compared to the control group. Regarding the gene expression profile, 51 genes showed deregulated, of which 46 genes with upregulation and downregulation of 5 genes. Three tRNAs were downregulated due to exposure to TCDD. Furthermore, 30 piRNAs proved deregulated, 17 piRNAs with upregulation and 13 with downregulation when comparing the groups. 7 different matrix families of transcription factor binding sites showed statistically significant expression in Sertoli cells after exposure to TCDD. Several pathways have been altered by the action of the toxic agent. Furthermore, our study showed a low number of similar genes among the most expressed among humans, rats and mice, which reflects the physiology of each species and alerts the caution when using animal models as substitutes for human exposure.
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Palavras-chave
Células de Sertoli, TCDD, miRNAs, RNAseq, Infertilidade, Sertoli cells, Infertility