Evidence for an X-linked genetic component in familial typical migraine

Migraine is a common complex disorder that shows strong familial aggregation. There is a general increased prevalence of migraine in females compared with males, with recent studies indicating that migraine affects 18% of females compared with 6% of males. This preponderance of females among migraine sufferers coupled with evidence of an increased risk of migraine in first degree relatives of male probands but not in relatives of female probands suggests the possibility of an X-linked dominant gene. We report here the localization of a typical migraine susceptibility locus to the X chromosome. Of three large multigenerational migraine pedigrees two families showed significant excess allele sharing to Xq markers (P = 0.031 and P = 0.012). Overall analysis of data from all three pedigrees gave significant evidence in support of linkage and heterogeneity (HLOD = 3.1). These findings provide conclusive evidence that familial typical migraine is a heterogeneous disorder. We suggest that the localization of a migraine susceptibility locus to the X chromosome could in part explain the increased risk of migraine in relatives of male probands and may be involved in the increased female prevalence of this disorder.

High resolution melt analysis : a novel method for studying the genetic relatedness of Pseudomonas aeruginosa isolates from clinical and environmental sources

A novel method was developed for studying the genetic relatedness of Pseudomonas aeruginosa isolates from clinical and environmental sources. This bacterium is ubiquitous in the natural environment and is an important pathogen known to infect Cystic Fibrosis (CF) patients. The transmission route of strains has not yet been defined; current theories include acquisition from an environmental source or through patient-to-patient spread. A highly discriminatory, bioinformatics based, DNA typing method was developed to investigate the relatedness of clinical and environmental isolates. This study found a similarity between the environmental and several CF clonal strains and also highlighted occurrence of environmental P. aeruginosa strains in CF infections.

Familial typical migraine: Linkage to chromosome 19p13 and evidence for genetic heterogeneity

Migraine is a frequent familial disorder that, in common with most multifactorial disorders, has an unknown etiology. The authors identified several families with multiple individuals affected by typical migraine using a single set of diagnostic criteria and studied these families for cosegregation between the disorder and markers on chromosome 19, the location of a mutation that causes a rare form of familial hemiplegic migraine (FHM). One large tested family showed both cosegregation and significant allele sharing for markers situated within or adjacent to the FHM locus. Multipoint GENEHUNTER results indicated significant excess allele sharing across a 12.6- cM region containing the FHM Ca2+ channel gene, CACNL1A4 (maximum nonparametric linkage Z score = 6.64, p = 0.0026), with a maximum parametric lod score of 1.92 obtained for a (CAG)(n) triplet repeat polymorphism situated in exon 47 of this gene. The CAG expansion did not, however, appear to be the cause of migraine in this pedigree. Other tested families showed neither cosegregation nor excess allele sharing to chromosome 19 markers. HOMOG analysis indicated heterogeneity, generating a maximum HLOD score of 3.6. It was concluded that Chr19 mutations either in the CACNL1A4 gene or a closely linked gene are implicated in some pedigrees with familial typical migraine, and that the disorder is genetically heterogeneous.

Prevalence of chronic ocular diseases in a genetic isolate : the Norfolk Island Eye Study (NIES)

Purpose: Over 40% of the permanent population of Norfolk Island possesses a unique genetic admixture dating to Pitcairn Island in the late 18 th century, with descendents having varying degrees of combined Polynesian and European ancestry. We conducted a population-based study to determine the prevalence and causes of blindness and low vision on Norfolk Island. Methods: All permanent residents of Norfolk Island aged ≥ 15 years were invited to participate. Participants completed a structured questionnaire/interview and underwent a comprehensive ophthalmic examination including slit-lamp biomicroscopy. Results: We recruited 781 people aged ≥ 15, equal to 62% of the permanent population, 44% of whom could trace their ancestry to Pitcairn Island. No one was bilaterally blind. Prevalence of unilateral blindness (visual acuity [VA] < 6/60) in those aged ≥ 40 was 1.5%. Blindness was more common in females (P=0.049) and less common in people with Pitcairn Island ancestry (P<0.001). The most common causes of unilateral blindness were age-related macular degeneration (AMD), amblyopia, and glaucoma. Five people had low vision (Best-Corrected VA < 6/18 in better eye), with 4 (80%) due to AMD. People with Pitcairn Island ancestry had a lower prevalence of AMD (P<0.001) but a similar prevalence of glaucoma to those without Pitcairn Island ancestry. Conclusions: The prevalence of blindness and visual impairment in this isolated Australian territory is low, especially amongst those with Pitcairn Island ancestry. AMD was the most common cause of unilateral blindness and low vision. The distribution of chronic ocular diseases on Norfolk Island is similar to mainland Australian estimates.

A genetic variant located in miR-423 is associated with reduced breast cancer risk

Background/Aim: Since microRNAs (miRNAs) act as translational regulators of multiple genes, single nucleotide polymorphisms (SNP) in them can have potentially wide-ranging effects. Using an association approach, this research examined the effects of the rs6505162 SNP, an A>C polymorphism located in the premiRNA region of miR-423, on breast cancer development. Materials and Methods: Caucasian Australian women with breast cancer and controls matched for age and ethnicity were genotyped for rs6505162 and their genotypic and allelic frequencies analysed for significant differences. Results: Analysis indicated that there were significant differences between the case and control populations (χ 2=6.70, p=0.035), with the CC genotype conferring reduced risk of breast cancer development (odds ratio=0.50 95% confidence interval=0.27-0.92, p=0.03). Conclusion: Further functional research is required to determine the mechanism of action of this SNP on miRNA function.

Genetic variation in cytokine-related genes and migraine susceptibility

Migraine is classified by the World Health Organization (WHO) as being one of the top 20 most debilitating diseases. According to the neurovascular hypothesis, neuroinflammation may promote the activation and sensitisation of meningeal nociceptors, inducing the persistent throbbing headache characterized in migraine. The tumor necrosis factor (TNF) gene cluster, made up of TNFα, lymphotoxin α (LTA), and lymphotoxin β (LTB), has been implicated to influence the intensity and duration of local inflammation. It is thought that sterile inflammation mediated by LTA, LTB, and TNFα contributes to threshold brain excitability, propagation of neuronal hyperexcitability and thus initiation and maintenance of a migraine attack. Previous studies have investigated variants within the TNF gene cluster region in relation to migraine susceptibility, with largely conflicting results. The aim of this study was to expand on previous research and utilize a large case-control cohort and range of variants within the TNF gene cluster to investigate the role of the TNF gene cluster in migraine. Nine single nucleotide polymorphisms (SNPs) were selected for investigation as follows: rs1800683, rs2229094, rs2009658, rs2071590, rs2239704, rs909253, rs1800630, rs1800629, and rs3093664. No significant association with migraine susceptibility was found for any of the SNPs tested, with further testing according to migraine subtype and gender also showing no association for disease risk. Haplotype analysis showed that none of the tested haplotypes were significantly associated with migraine.

Molecular genetic analyses of RFLPs for PCR-amplified growth hormone gene, renal kallikrein gene and atrial natriuretic factor gene in essential hypertension

The present study examined polymorphisms of genes that might be involved in the onset of essential hypertension (HT). These included the (i) growth hormone gene (GH1), whose locus has recently been linked to elevated blood pressure (BP) in the stroke-prone SHR, although recent sib-pair analysis of a polymorphism near the human chorionic somatomammotropin gene (a member of the GH cluster) was unable to show linkage with HT; (ii) renal kallikrein gene (KLK1); and (iii) atrial natriuretic factor gene (ANF), where a primary defect in production or activity of kallikrein or ANF could cause NaCl retention and vasoconstriction. Association analyses were conducted to compare restriction fragment length polymorphisms (RFLPs) of each gene in 85 HT and 95 normotensive (NT) Caucasian subjects whose parents had a similar BP status at age ≥50 years. The frequency of the minor allele of (i) a RsaI RFLP in the promoter of GH1, amplified from leukocyte DNA by the polymerase chain reaction, was 0.15 in the HT group and 0.14 in the NT group (χ1=0.34, P=0.55); (ii) a TaqI RFLP for KLK1 was 0.035 in the HT group and 0.015 in the NT group (χ2=1.5, P=0.21); and (iii) a XhoI RFLP for ANF was 0.50 in HTs and 0.46 in NTs (χ2=0.20, P=0.65). Studies of HT pedigrees found one family in which the ANF locus and HT were not linked, owing to an obligate recombinant. The present data thus provide no evidence for involvement of the growth hormone, renal kallikrein, nor ANF gene in the causation of essential hypertension.

Genetic susceptibility to complex traits : moving towards informed analysis of whole-genome screens

Susceptibility to complex traits, by definition, involves aetiological polymorphisms at multiple genetic loci combined with variable contributions by environmental factors. However, the approaches taken to identifying genetic loci implicated in susceptibility to complex traits frequently overlooks the compounding contribution of multiple loci in favour of highlighting a single gene solely responsible for predisposition. It is only in a small minority of cases that this has resulted in clear disease heritability associated with polymorphisms in a single gene. More often, this approach has led to an accumulation of single-gene associations with minor contributions to disease susceptibility. As the genomic era advances and genome-wide screens become higher in resolution and throughput, the need for simultaneous consideration of multiple loci is becoming more important. With special reference to non-Hodgkin’s lymphoma (NHL), this chapter will overview the current progress made in elucidating genetic polymorphisms associated with disease susceptibility. We also present novel data from a high-resolution single nucleotide polymorphism (SNP) microarray screen for susceptibility loci that are involved in NHL. Using an ‘informed approach’, the findings are highlighted within the context of cellular pathways, and provide insight and new ideas for methods of analysis for genome-wide screens for susceptibility.

The role of EBV-encoded microRNAs in B cell differentiation

Epstein Barr virus (EBV) is a common γ-herpes virus, infecting approximately 90% of the world‟s population. It is also one of the first known viruses known to be oncogenic, and is associated with a number of tumour types, primarily lymphomas. MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression and many human miRNAs have been associated with the development of malignancies including cancer. EBV was the first human virus identified to express miRNAs and encodes more than 40 miRNAs within its genome. Yet, an understanding of the targets of EBV-miRNAs, and thereby the function of them in pathogenesis remains sadly limited. This study identifies a potential novel target of EBV-miRNAs, MECP2 and characterises the miRNA:mRNA interactions between two previously identified novel targets; Bim and EBF1. In particular, this study focuses upon the interaction between EBF1 and the EBV-miRNA BART11-5p, demonstrating a 151bp region of the EBF1 3‟UTR that is capable of mediating the silencing of luciferase expression by BART11-5p but is not capable of silencing a full length EBF1-3‟UTR luciferase construct. This study provides evidence that EBF1 may be a target of one or more EBV-miRNAs.

Osteogenic differentiation of bone marrow MSCs by β-tricalcium phosphate stimulating macrophages via BMP2 signalling pathway

Immune reactions play important roles in determining the in vivo fate of bone substitute materials, either in new bone formation or inflammatory fibrous tissue encapsulation. The paradigm for the development of bone substitute materials has been shifted from inert to immunomodulatory materials, emphasizing the importance of immune cells in the material evaluation. Macrophages, the major effector cells in the immune reaction to implants, are indispensable for osteogenesis and their heterogeneity and plasticity render macrophages a primer target for immune system modulation. However, there are very few reports about the effects of macrophages on biomaterial-regulated osteogenesis. In this study, we used b-tricalcium phosphate (b-TCP) as a model biomaterial to investigate the role of macrophages on the material stimulated osteogenesis. The macrophage phenotype switched to M2 extreme in response to b-TCP extracts, which was related to the activation of calcium-sensing receptor (CaSR) pathway. Bone morphogenetic protein 2 (BMP2) was also significantly upregulated by the b-TCP stimulation, indicating that macrophage may participate in the b-TCP stimulated osteogenesis. Interestingly, when macrophageconditioned b-TCP extracts were applied to bone marrow mesenchymal stem cells (BMSCs), the osteogenic differentiation of BMSCs was significantly enhanced, indicating the important role of macrophages in biomaterial-induced osteogenesis. These findings provided valuable insights into the mechanism of material-stimulated osteogenesis, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of bone substitute materials.

Mussel-inspired bioceramics with self-assembled Ca-P/polydopamine composite nanolayer : preparation, formation mechanism, improved cellular bioactivity and osteogenic differentiation of bone marrow stromal cells

The nanostructured surface of biomaterials plays an important role in improving their in vitro cellular bioactivity as well as stimulating in vivo tissue regeneration. Inspired by the mussel’s adhesive versatility, which is thought to be due to the plaque–substrate interface being rich in 3,4-dihydroxy-L-phenylalamine (DOPA) and lysine amino acids, in this study we developed a self-assembly method to prepare a uniform calcium phosphate (Ca-P)/polydopamine composite nanolayer on the surface of b-tricalcium phosphate (b-TCP) bioceramics by soaking b-TCP bioceramics in Tris–dopamine solution. It was found that the addition of dopamine, reaction temperature and reaction time are three key factors inducing the formation of a uniform Ca-P/polydopamine composite nanolayer. The formation mechanism of a Ca-P/polydopamine composite nanolayer involved two important steps: (i) the addition of dopamine to Tris–HCl solution decreases the pH value and accelerates Ca and P ionic dissolution from the crystal boundaries of b-TCP ceramics; (ii) dopamine is polymerized to form self-assembled polydopamine film and, at the same time, nanosized Ca-P particles are mineralized with the assistance of polydopamine, in which the formation of polydopamine occurs simultaneously with Ca-P mineralization (formation of nanosized microparticles composed of calcium phosphate-based materials), and finally a self-assembled Ca-P/polydopamine composite nanolayer forms on the surface of the b-TCP ceramics. Furthermore, the formed self-assembled Ca-P/polydopamine composite nanolayer significantly enhances the surface roughness and hydrophilicity of b-TCP ceramics, and stimulates the attachment, proliferation, alkaline phosphate (ALP) activity and bone-related gene expression (ALP, OCN, COL1 and Runx2) of human bone marrow stromal cells. Our results suggest that the preparation of self-assembled Ca-P/polydopamine composite nanolayers is a viable method to modify the surface of biomaterials by significantly improving their surface physicochemical properties and cellular bioactivity for bone regeneration application.

In arrayed ranks array technology in the study of mesothelioma steven

Mesothelioma is a rare malignancy arising from mesothelial cells lining the pleura and peritoneum. Advances in modern technology have allowed the development of array based approaches to the study of disease allowing researchers the opportunity to study many genes or proteins in a high-throughput fashion. This review describes the current knowledge surrounding array based approaches with respect to mesothelioma research. © 2009 by the International Association for the Study of Lung Cancer.

Gene expression analysis of diagnostic biopsies predicts pathological response to neoadjuvant chemoradiotherapy of esophageal cancer

OBJECTIVE: This study explored gene expression differences in predicting response to chemoradiotherapy in esophageal cancer. PURPOSE:: A major pathological response to neoadjuvant chemoradiation is observed in about 40% of esophageal cancer patients and is associated with favorable outcomes. However, patients with tumors of similar histology, differentiation, and stage can have vastly different responses to the same neoadjuvant therapy. This dichotomy may be due to differences in the molecular genetic environment of the tumor cells. BACKGROUND DATA: Diagnostic biopsies were obtained from a training cohort of esophageal cancer patients (13), and extracted RNA was hybridized to genome expression microarrays. The resulting gene expression data was verified by qRT-PCR. In a larger, independent validation cohort (27), we examined differential gene expression by qRT-PCR. The ability of differentially-regulated genes to predict response to therapy was assessed in a multivariate leave-one-out cross-validation model. RESULTS: Although 411 genes were differentially expressed between normal and tumor tissue, only 103 genes were altered between responder and non-responder tumor; and 67 genes differentially expressed >2-fold. These included genes previously reported in esophageal cancer and a number of novel genes. In the validation cohort, 8 of 12 selected genes were significantly different between the response groups. In the predictive model, 5 of 8 genes could predict response to therapy with 95% accuracy in a subset (74%) of patients. CONCLUSIONS: This study has identified a gene microarray pattern and a set of genes associated with response to neoadjuvant chemoradiation in esophageal cancer. The potential of these genes as biomarkers of response to treatment warrants further investigation. Copyright © 2009 by Lippincott Williams & Wilkins.

Investigation of genetic diversity and development of vaccine for Chlamydia pecorum infections in koala (Phascolarctos cinereus)

Many wild koala populations in Australia continue to experience serious declines due to factors such as disease caused by Chlamydia. This thesis is the first of its kind to investigate diversity of the chlamydial infections in wild koala populations across Australia and has made significant progress towards the development of a vaccine for koalas. The findings in this study have demonstrated that it is feasible to develop a safe and effective recombinant vaccine against Chlamydia in both disease free as well as severely diseased koalas. Most importantly, this study is also first of its kind to evaluate a multi-component vaccine that should be effective against the range of Chlamydia pecorum strains circulating in both captive as well as wild koala populations.

Differentiation of isomeric N-glycan structures by normal-phase liquid chromatography-MALDI-TOF/TOF tandem mass spectrometry

The detailed characterization of protein N-glycosylation is very demanding given the many different glycoforms and structural isomers that can exist on glycoproteins. Here we report a fast and sensitive method for the extensive structure elucidation of reducing-end labeled N-glycan mixtures using a combination of capillary normal-phase HPLC coupled off-line to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and TOF/TOF-MS/MS. Using this method, isobaric N-glycans released from honey bee phospholipase A2 and Arabidopsis thaliana glycoproteins were separated by normal-phase chromatography and subsequently identified by key fragment ions in the MALDI-TOF/TOF tandem mass spectra. In addition, linkage and branching information were provided by abundant cross-ring and "elimination" fragment ions in the MALDI-CID spectra that gave extensive structural information. Furthermore, the fragmentation characteristics of N-glycans reductively aminated with 2-aminobenzoic acid and 2-aminobenzamide were compared. The identification of N-glycans containing 3-linked core fucose was facilitated by distinctive ions present only in the MALDI-CID spectra of 2-aminobenzoic acid-labeled oligosaccharides. To our knowledge, this is the first MS/MS-based technique that allows confident identification of N-glycans containing 3-linked core fucose, which is a major allergenic determinant on insect and plant glycoproteins.