Age-related differences in integrin expression in peripheral blood lymphocytes

Alpha integrins play an important role in cell to cell and cell to extra-cellular matrix interactions required for an effective T-lymphocyte-mediated immune response, however little is known about age related differences in expression of alpha integrins on T-cells in humans. We here measured alpha-4 (α4) integrin (CD49d) expression on T-lymphocytes via peripheral blood sampling, comparing parameters between cohorts of young and old adults. No age-related differences were found for the absolute numbers of T-cells, although the percentage of CD4+ T-cells in older adults was significantly greater and the percentage of CD8+ T-cells lower than in younger cohorts. Percentage and absolute numbers of CD3+ T-cells co-expressing CD49d were significantly lower in older adults compared to younger cohorts, and the percentage of gated CD4+ and CD8+ cells that co-labelled positively for CD49d was also reduced in this group. There were no age-related differences in circulating levels of cytokines (Type I interferons) that are known to regulate cell surface integrin expression. Reduced expression of alpha integrins on T-cells may be an early indicator of the loss of homeostatic control that occurs with ageing, contributing to diminished effector T-cell responses during senescence

DNA Dynamics Is Likely to Be a Factor in the Genomic Nucleotide Repeats Expansions Related to Diseases

Trinucleotide repeats sequences (TRS) represent a common type of genomic DNA motif whose expansion is associated with a large number of human diseases. The driving molecular mechanisms of the TRS ongoing dynamic expansion across generations and within tissues and its influence on genomic DNA functions are not well understood. Here we report results for a novel and notable collective breathing behavior of genomic DNA of tandem TRS, leading to propensity for large local DNA transient openings at physiological temperature. Our Langevin molecular dynamics (LMD) and Markov Chain Monte Carlo (MCMC) simulations demonstrate that the patterns of openings of various TRSs depend specifically on their length. The collective propensity for DNA strand separation of repeated sequences serves as a precursor for outsized intermediate bubble states independently of the G/C-content. We report that repeats have the potential to interfere with the binding of transcription factors to their consensus sequence by altered DNA breathing dynamics in proximity of the binding sites. These observations might influence ongoing attempts to use LMD and MCMC simulations for TRS–related modeling of genomic DNA functionality in elucidating the common denominators of the dynamic TRS expansion mutation with potential therapeutic applications

The Identification of Zebrafish Mutants Showing Alterations in Senescence-Associated Biomarkers

There is an interesting overlap of function in a wide range of organisms between genes that modulate the stress responses and those that regulate aging phenotypes and, in some cases, lifespan. We have therefore screened mutagenized zebrafish embryos for the altered expression of a stress biomarker, senescence-associated β-galactosidase (SA-β-gal) in our current study. We validated the use of embryonic SA-β-gal production as a screening tool by analyzing a collection of retrovirus-insertional mutants. From a pool of 306 such mutants, we identified 11 candidates that showed higher embryonic SA-β-gal activity, two of which were selected for further study. One of these mutants is null for a homologue of Drosophila spinster, a gene known to regulate lifespan in flies, whereas the other harbors a mutation in a homologue of the human telomeric repeat binding factor 2 (terf2) gene, which plays roles in telomere protection and telomere-length regulation. Although the homozygous spinster and terf2 mutants are embryonic lethal, heterozygous adult fish are viable and show an accelerated appearance of aging symptoms including lipofuscin accumulation, which is another biomarker, and shorter lifespan. We next used the same SA-β-gal assay to screen chemically mutagenized zebrafish, each of which was heterozygous for lesions in multiple genes, under the sensitizing conditions of oxidative stress. We obtained eight additional mutants from this screen that, when bred to homozygosity, showed enhanced SA-β-gal activity even in the absence of stress, and further displayed embryonic neural and muscular degenerative phenotypes. Adult fish that are heterozygous for these mutations also showed the premature expression of aging biomarkers and the accelerated onset of aging phenotypes. Our current strategy of mutant screening for a senescence-associated biomarker in zebrafish embryos may thus prove to be a useful new tool for the genetic dissection of vertebrate stress response and senescence mechanisms

Cytogenetic abnormalities and fragile-x syndrome in Autism Spectrum Disorder

BACKGROUND: Autism is a behavioral disorder with impaired social interaction, communication, and repetitive and stereotypic behaviors. About 5–10 % of individuals with autism have 'secondary' autism in which an environmental agent, chromosome abnormality, or single gene disorder can be identified. Ninety percent have idiopathic autism and a major gene has not yet been identified. We have assessed the incidence of chromosome abnormalities and Fragile X syndrome in a population of autistic patients referred to our laboratory. METHODS: Data was analyzed from 433 patients with autistic traits tested using chromosome analysis and/or fluorescence in situ hybridization (FISH) and/or molecular testing for fragile X syndrome by Southern and PCR methods. RESULTS: The median age was 4 years. Sex ratio was 4.5 males to 1 female [354:79]. A chromosome (cs) abnormality was found in 14/421 [3.33 %] cases. The aberrations were: 4/14 [28%] supernumerary markers; 4/14 [28%] deletions; 1/14 [7%] duplication; 3/14 [21%] inversions; 2/14 [14%] translocations. FISH was performed on 23 cases for reasons other than to characterize a previously identified cytogenetic abnormality. All 23 cases were negative. Fragile-X testing by Southern blots and PCR analysis found 7/316 [2.2 %] with an abnormal result. The mutations detected were: a full mutation (fM) and abnormal methylation in 3 [43 %], mosaic mutations with partial methylation of variable clinical significance in 3 [43%] and a permutation carrier [14%]. The frequency of chromosome and fragile-X abnormalities appears to be within the range in reported surveys (cs 4.8-1.7%, FRAX 2–4%). Limitations of our retrospective study include paucity of behavioral diagnostic information, and a specific clinical criterion for testing. CONCLUSIONS: Twenty-eight percent of chromosome abnormalities detected in our study were subtle; therefore a high resolution cytogenetic study with a scrutiny of 15q11.2q13, 2q37 and Xp23.3 region should be standard practice when the indication is autism. The higher incidence of mosaic fragile-X mutations with partial methylation compared to FRAXA positive population [50% vs 15–40%] suggests that faint bands and variations in the Southern band pattern may occur in autistic patients

Minimal important differences for interpreting health-related quality of life scores from the EORTC QLQ-C30 in lung cancer patients participating in randomized controlled trials

The aim of this study was to determine the smallest changes in health-related quality of life (HRQOL) scores in a subset of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire core 30 (EORTC QLQ-C30) scales, which could be considered as clinically meaningful in patients with non-small-cell lung cancer (NSCLC). WHO performance status (PS) and weight change were used as clinical anchors to determine minimal important differences (MIDs) in HRQOL change scores (range, 0-100) in the EORTC QLQ-C30 scales. Selected distribution-based methods were used for comparison. In a pooled dataset of 812 NSCLC patients undergoing treatment, the values determined to represent the MID depended on whether patients were improving or deteriorating. MID estimates for improvement (based on a one-category change in PS, 5 -aEuro parts per thousand < 20% weight gain) were physical functioning (9, 5); role functioning (14, 7); social functioning (5, 7); global health status (9, 4); fatigue (14, 5); and pain (16, 2). The respective MID estimates for deterioration (based on PS, weight loss) were physical (4, 6); role (5, 5); social (7, 9); global health status (4, 4); fatigue (6, 11); and pain (3, 7). Based on the selected QLQ-C30 scales, the MID may depend upon whether the patients' PS is improving or worsening, but our results are not definitive. The MID estimates for the specified scales can help clinicians and researchers evaluate the significance of changes in HRQOL and assess the value of a health care intervention or compare treatments. The estimates also can be useful in determining sample sizes in the design of future clinical trials

Comparative genomic analysis of innate immunity reveals novel and conserved components in crustacean food crop species

Abstract Background Growing global demands for crustacean food crop species have driven large investments in aquaculture research worldwide. However, large-scale production is susceptible to pathogen-mediated destruction particularly in developing economies. Thus, a thorough understanding of the immune system components of food crop species is imperative for research to combat pathogens. Results Through a comparative genomics approach utilising extant data from 55 species, we describe the innate immune system of the class Malacostraca, which includes all food crop species. We identify 7407 malacostracan genes from 39 gene families implicated in different aspects of host defence and demonstrate dynamic evolution of innate immunity components within this group. Malacostracans have achieved flexibility in recognising infectious agents through divergent evolution and expansion of pathogen recognition receptors genes. Antiviral RNAi, Toll and JAK-STAT signal transduction pathways have remained conserved within Malacostraca, although the Imd pathway appears to lack several key components. Immune effectors such as the antimicrobial peptides (AMPs) have unique evolutionary profiles, with many malacostracan AMPs not found in other arthropods. Lastly, we describe four putative novel immune gene families, potentially representing important evolutionary novelties of the malacostracan immune system. Conclusion Our analyses across the broader Malacostraca have allowed us to not only draw analogies with other arthropods but also to identify evolutionary novelties in immune modulation components and form strong hypotheses as to when key pathways have evolved or diverged. This will serve as a key resource for future immunology research in crustacean food crops