NR4A Nuclear Orphan Receptors show different expression levels in immune cells from RSA patients compared to fertile women

JOSEFINA STAGNARO; ILEANA ARMANNA; ELOÍSA ARANA; LEONARDO FAINBOIM; PABLO FERNANDEZ

CABA

Congreso; LASID/FAIC/SAI; 2015

Abstract: Spontaneous abortion is the most common complication of early pregnancy. Recurrent Spontaneous Abortion (RSA) is defined as three consecutive losses within the first 20 weeks of gestation. The majority of these recurrent losses remain unexplained. The NR4A orphan receptors function as ligand-independent transcription factors that regulate the expression of target genes. These receptors have been implicated in broader functions within the immune system cells. NR4A orphan nuclear receptors may play a role in restraining or increasing the effects of immune system cells in embryo development and implantation. NR4A mRNA expression levels were determined by real-time PCR in peripheral blood mononuclear cells (PBMCs), sorted cells (NK, CD4+, CD8+), and immune cells infiltrated in decidua. PBMCs were obtained from RSA patients, fertile and infertile women, and men. Decidua tissue samples were from hospital miscarriages. Statistical analysis was performed using GraphPad Prism 5 software. Groups were compared by Mann-Whitney test. Samples from PBMCs in RSA group showed significantly lower expression levels of NR4A1 (p =0.0136), NR4A2 (p=0.0027) and NR4A3 (p=0.0454) nuclear orphan receptors, when compared to fertile women. Interestingly, all three NR4A receptors in RSA group showed similar expression levels to the men?s group. NR4A3 expression level was also significantly lower in PBMCs from RSA group than infertile women (p=0.0450). Sorted cells and decidua results are discussed in the poster. These results strongly support our hypothesis that NR4A nuclear receptors play an important role in immunological tolerance mechanisms and encourage our efforts to study their expression in endometrial infiltrated immune cells