Análise da expressão de genes envolvidos na resposta inflamatória em crianças com síndrome de Down

Abstract

ABSTRACT Introduction: Down syndrome (DS) is a genetic disorder caused by the presence of an extra copy of human chromosome 21 (HSA21) with an incidence of one in 660 live births. Individuals with DS show alterations of the immune system resulting in increased frequency of infections and autoimmune diseases. Studies show that some genes involved in the immune system present altered expression in individuals with DS, however, the molecular mechanisms by which trisomy 21 leads to the immune system disorders in DS remain poorly investigated. Objective: This study aimed to investigate the expression pattern of a specific set of genes involved in the immune system and inflammation process in children with DS and children without the syndrome (control group), to identify differences that may be related to clinical manifestations of the syndrome. Casuistic and Methods: In this study were included six children with DS and six children without the syndrome. The quantification of the gene expression was performed using TaqMan ® Array Plate Human Inflammation Kit, which enables the investigation of 92 inflammation-related genes and four reference genes by real-time polymerase chain reaction (qPCR). Results: Of the 92 genes analyzed, 20 genes showed differential expression in children DS; 12 overexpressed (PLA2G2D, CACNA1D, ALOX12, VCAM1, ICAM1, PLCD1, ADRB1, HTR3A, PDE4C, CASP1, PLA2G5 e PLCB4) and 8 underexpressed (LTA4H, BDKRB1, ADRB2, CD40LG, ITGAM, TNFRSF1B, ITGB1 e TBXAS1). After statistical correction for false discovery rate, only the genes BDKRB1 and LTA4H showed differential expression, both underexpressed. Conclusion: DS children show differential expression of genes, not located on chromosome 21, compared to children without DS. The altered expression of these genes, considering their functions in the inflammatory response, suggests an important role in DS pathogenesis.