The role of cytokines in first trimester pregnancy losses with fetal chromosomal anomaly.

OBJECTIVES: The contribution of local inflammation to the pathophysiology of abnormal choromosomally miscarriages remains unclear The objective of this study was to investigate the inflammatory response at the maternofetal interface of women presenting with first trimester miscarriage with abnormal choromosomally MATERIAL AND METHODS: Level of TNF-α , IL-6 ve IL-17 were asseyed using immunohistochemistry technique at decidual and placental bed biopsy samples from 23 women with elective termination of pregnancy 21 euploid and 18 aneuploid missed miscarriages. Immunostainig for TNF-α, IL-6 ve IL-17 has been evaluated semi-quantitatively by 'quickscore' method. RESULTS: We found that the intensity of TNF-α staining was high in the miscarriage group, and this has been found in previous studies. Unlike some previous studies, the intensity of IL-6 staining was higher in the miscarriage groups only in decidual glandular epithelium. The intensity of IL-6 staining was found to be higher in the miscarriage group with chromosome anomaly than in the miscarriage group without chromosome anomaly. There was no significant difference in IL-17 levels between any of the groups. CONCLUSIONS: Cytokines are considered to play an important role in the maintenance of pregnancy but the exact mechanism between them and the mutual regulation relationship were not been fully understood, which need our further study.

Altered expression of autoimmune regulator in infant down syndrome thymus, a possible contributor to an autoimmune phenotype.

Down syndrome (DS), caused by trisomy of chromosome 21, is associated with immunological dysfunctions such as increased frequency of infections and autoimmune diseases. Patients with DS share clinical features, such as autoimmune manifestations and specific autoantibodies, with patients affected by autoimmune polyendocrine syndrome type 1. Autoimmune polyendocrine syndrome type 1 is caused by mutations in the autoimmune regulator (AIRE) gene, located on chromosome 21, which regulates the expression of tissue-restricted Ags (TRAs) in thymic epithelial cells. We investigated the expression of AIRE and TRAs in DS and control thymic tissue using quantitative PCR. AIRE mRNA levels were elevated in thymic tissue from DS patients, and trends toward increased expression of the AIRE-controlled genes INSULIN and CHRNA1 were found. Immunohistochemical stainings showed altered cell composition and architecture of the thymic medulla in DS individuals with increased frequencies of AIRE-positive medullary epithelial cells and CD11c-positive dendritic cells as well as enlarged Hassall's corpuscles. In addition, we evaluated the proteomic profile of thymic exosomes in DS individuals and controls. DS exosomes carried a broader protein pool and also a larger pool of unique TRAs compared with control exosomes. In conclusion, the increased AIRE gene dose in DS could contribute to an autoimmune phenotype through multiple AIRE-mediated effects on homeostasis and function of thymic epithelial cells that affect thymic selection processes.

Identification of dysregulated microRNAs in lymphocytes from children with Down syndrome.

Given the important roles of miRNAs in post-transcriptional regulation and its implications for the development of immune tissues and cells, characterization of miRNAs promotes us to uncover the molecular mechanisms underlying the pathway of trisomic chromosome 21 that disrupts the disomic genes expression and immunological defects related to Down syndrome (DS). In the present study, we analyzed global changes and chromosome distribution characteristics of miRNAs expression in lymphocytes from children with trisomy 21 by means of the Illumina high-throughput sequencing technology. Two small libraries were constructed using pool RNA of normal and DS children. The results have been further validated by stem-loop quantitative RT-PCR. Comparison between DS and normal profiles revealed that most of identified miRNAs were expressed at similar levels. The chromosome 21 that contributes to the abundantly expressed miRNAs was small, and not all Hsa21-derived miRNAs were over-expressed with ratios significantly ≥ 1.5 in Down syndrome children lymphocytes. Based on the deep sequencing technology, 108 novel candidate miRNAs have been identified, and 2 of them were derived from human chromosome 21. For the 114 significantly differentially expressed miRNAs, function annotation of target genes indicated that a set of highly abundantly and significantly differentially expressed miRNAs were involved in hematopoietic or lymphoid organ development, thymus development, and T/B cell differentiation and activation. Our results indicated that these abnormally expressed miRNAs might be associated with the mechanisms that trisomy 21 results in dysregulation of disomic genes and involved in the immunological defects seen in DS.

Genome-wide expression analysis in Down syndrome: insight into immunodeficiency.

Down syndrome (DS) is caused by triplication of Human chromosome 21 (Hsa21) and associated with an array of deleterious phenotypes, including mental retardation, heart defects and immunodeficiency. Genome-wide expression patterns of uncultured peripheral blood cells are useful to understanding of DS-associated immune dysfunction. We used a Human Exon microarray to characterize gene expression in uncultured peripheral blood cells derived from DS individuals and age-matched controls from two age groups: neonate (N) and child (C). A total of 174 transcript clusters (gene-level) with eight located on Hsa21 in N group and 383 transcript clusters including 56 on Hsa21 in C group were significantly dysregulated in DS individuals. Microarray data were validated by quantitative polymerase chain reaction. Functional analysis revealed that the dysregulated genes in DS were significantly enriched in two and six KEGG pathways in N and C group, respectively. These pathways included leukocyte trans-endothelial migration, B cell receptor signaling pathway and primary immunodeficiency, etc., which causally implicated dysfunctional immunity in DS. Our results provided a comprehensive picture of gene expression patterns in DS at the two developmental stages and pointed towards candidate genes and molecular pathways potentially associated with the immune dysfunction in DS.

NOR expression increases on metaphase chromosomes of Down syndrome lymphocytes in concordance with mitogen concentration in culture medium.

BACKGROUND: Regulation of nucleolus organizer region (NOR) expression in trisomy 21 (Down syndrome [DS]) cells is not fully explained. This work compared NOR expression on metaphase chromosomes in gradiently stimulated lymphocytes from DS patients with those from healthy controls. METHOD: Conventional peripheral blood culture (72 h) and chromosomal preparation procedures were used except that blood samples from each individual were cultivated in the same but gradiently increasing concentrations (0.37, 0.75, 1.48, and 2.21 ml) of phytohemagglutinin (PHA) per 100 ml of medium. One hundred consecutive metaphases per concentration were analyzed for scoring the means of the active NORs bearing chromosomes (AgNOR+ chromosome) per individual and per concentration. RESULTS: In contrast to healthy controls (n=24), AgNOR+ chromosomal number in lymphocytes from 30 DS patients increased in concordance to the gradient of PHA concentration in the culture medium. CONCLUSION: DS lymphocytes do not downregulate their NOR expression in the limit of control cells. This in vitro result may serve as a clue for the explanation of the DS phenotype due to the wasted energy in producing unnecessary rRNA transcripts and AgNOR proteins in utero during organogenesis. These results also indicate that precautions must be used in routine work of NOR evaluation/interpretation in DS lymphocytes.