Search

The mutational spectrum of many genes and their contribution to the global prevalence of hereditary hearing loss is still widely unknown. In this study, we have performed the mutational screening of EYA4 gene by DHLPC and NGS in a large cohort of 531 unrelated Spanish probands and one Australian family with autosomal dominant non-syndromic hearing loss (ADNSHL). In total, 9 novel EYA4 variants have been identified, 3 in the EYA4 variable region (c.160G > T; p.Glu54*, c.781del; p.Thr261Argfs*34 and c.1078C > A; p.Pro360Thr) and 6 in the EYA-HR domain (c.1107G > T; p.Glu369Asp, c.1122G > T; p.Trp374Cys, c.1281G > A; p.Glu427Glu, c.1282-1G > A, c.1601C > G; p.S534* and an heterozygous copy number loss encompassing exons 15 to 17). The contribution of EYA4 mutations to ADNSHL in Spain is, therefore, very limited (~1.5%, 8/531). The pathophysiology of some of these novel variants has been explored. Transient expression of the c-myc-tagged EYA4 mutants in mammalian COS7 cells revealed absence of expression of the p.S534* mutant, consistent with a model of haploinsufficiency reported for all previously described EYA4 truncating mutations. However, normal expression pattern and translocation to the nucleus were observed for the p.Glu369Asp mutant in presence of SIX1. Complementary in silico analysis suggested that c.1107G > T (p.Glu369Asp), c.1281G > A (p.Glu427Glu) and c.1282-1G > A variants alter normal splicing. Minigene assays in NIH3T3 cells further confirmed that all 3 variants caused exon skipping resulting in frameshifts that lead to premature stop codons. Our study reports the first likely pathogenic synonymous variant linked to DFNA10 and provide further evidence for haploinsufficiency as the common underlying disease-causing mechanism for DFNA10-related hearing loss. [ABSTRACT FROM AUTHOR]

The defective major histocompatibility complex (MHC) DRB6 gene is transcribed into mRNA in human [peripheral blood lymphocytes, transfected and Epstein-Barr virus (EBV)] and chimpanzee EBV cell lines. MHC-DRB6 presents several anomalies, which include stop codons in exon 2, lack of the usual polyadenilation signal of other MHC-DRB genes, and a promoter region and exon 1 taken from a locally inserted retrovirus. The complete cDNA sequences from human DRB6*0201 and three common chimpanzee alleles ( Patr-DRB6*0108, Patr-DRB6*0109, Patr-DRB6*0111) have been obtained; two exon 1-exon 2 cDNA sequences from bonobos ( Papa-DRB6*0101 and Papa-DRB6*0102) are also shown. In contrast to chimpanzee DRB6 transcripts, the human ones: (1) present an exon 1-exon 2 splicing site that includes the transcription of the first 141 nucleotides of intron 1, rendering a longer exon 1, and (2) show a duplication of exon 6, which would render a longer cytoplasmic tail in a putative DRB6 protein. These two characteristics are found in all the human sequences obtained, regardless of the cellular type tested, and they are not present in any of the chimpanzee alleles reported; consequently, they are human-specific. All the alleles reported here bear stop codons in the three possible reading frames; however, a certain level of expression of DRB6 has been observed by cytofluorometry. This could be due to the presence of a selenocysteine insertion sequence (SECIS) stem-loop structure located at the 3 untranslated region of the DRB6 mRNA, which directs selenocysteine incorporation at UGA codons. DRB6 transcription and translation would be the first gene model of a readingthrough stop codon mechanism in primate MHC. It is also feasible that the DRB6 gene might generate a population of short polypeptides, bound to plasmatic membranes, having non-antigen-presenting functions or which are presented by other MHC molecules as HLA-E presents HLA-G and -B leader sequence-derived peptides. [ABSTRACT FROM AUTHOR]

Two batches of Helicella (H.) itala (adult specimens) and two of Cepaea nemoralis (adult and young specimens) were experimentally infected with larvae I (L-I) of Muellerius sp. and Neostrongylus linearis obtained from the lungs and faeces of Rupicapra rupicapra. In assess larval development, the number and percentage of the total number of larvae (L-I+L-II+L-III) per mollusc were studied, together with the number and percentage of L-III per snail and the days on which the different larval stages were reached. The development of Muellerius sp. and N. linearis was greater in larvae from faeces. For both species of molluscs, the values for the percentages of the total number of larvae and L-III were higher in N. linearis than in Muellerius sp., but there were no notable differences in the days on which the various larval stages were reached. Both nematodes achieved a greater degree of development in young specimens of C. nemoralis than in adults. Whether the larvae came from facces or the lungs, H. (H.) itala was a better intermediate host than C. nemoralis for Muellerius sp. and N. linearis. [ABSTRACT FROM AUTHOR]

Heterologous BCG prime-boost regimens represent a promising strategy for an urgently required improved tuberculosis vaccine. Identifying the mechanisms which underpin the enhanced protection induced by such strategies is one key aim which would significantly accelerate rational vaccine development. Experimentally, airway vaccination induces greater efficacy than parenteral delivery; in both conventional vaccination and heterologous boosting of parenteral BCG immunisation. However, the effect of delivering both the component prime and boost immunisations via the airway is not well known. Here we investigate delivery of both the BCG prime and adenovirus boost vaccination via the airway in a murine model, and demonstrate this approach may be able to improve the protective outcome over parenteral prime/airway boost. Intravascular staining of T cells in the lung revealed that the airway prime regimen induced more antigen-specific multifunctional CD4 and CD8 T cells to the lung parenchyma prior to challenge and indicated the route of both prime and boost to be critical to the location of induced resident T cells in the lung. Further, in the absence of a defined phenotype of vaccine-induced protection to tuberculosis; the magnitude and phenotype of vaccine-specific T cells in the parenchyma of the lung may provide insights into potential correlates of immunity. [ABSTRACT FROM AUTHOR]

Vitamin D deficiency has been related with metabolic alterations in polycystic ovary syndrome (PCOS). As well, hyperactivation of adrenal axis can be programmed early in life and could be related later with PCOS development. Our aim was to establish the relationship between vitamin D and adrenal parameters with metabolic alterations and inflammation markers in PCOS. In 73 patients and 33 controls, 25-hydroxyvitamin D (25-OH-D), total and bioavailable testosterone (TT and bioT), androstenedione (A4), SHBG, cortisol, insulin, and C-reactive protein (hs-CRP) were determined; HOMA and lipid accumulation product (LAP) index were calculated. All parameters were higher in patients than in controls, except for SHBG and 25-OH-D which were lower. Binary regression analysis showed that differences in TT, bioT, A4, insulin and HOMA were independent of body mass index and waist circumference but SHBG, hs-CRP, LAP and 25-OH-D were related to body weight and fat distribution. Binary logistic regression analysis showed that cortisol and 25-OH-D could be associated to PCOS development. Correlations found between LAP and insulin, HOMA and hs-CRP confirm it is a good indicator of metabolic complications. Vitamin D and cortisol association to PCOS development justifies future research to understand the role of vitamin D in PCOS and analyze patient's perinatal history and its possible relationship with hyperactivation of adrenal axis in adult life. [ABSTRACT FROM AUTHOR]