Type II Transmembrane Serine Protease Gene Variants Associate with Breast Cancer

Type II transmembrane serine proteases (TTSPs) are related to tumor growth, invasion, and metastasis in cancer. Genetic variants in these genes may alter their function, leading to cancer onset and progression, and affect patient outcome. Here, 464 breast cancer cases and 370 controls were genotyped for 82 single-nucleotide polymorphisms covering eight genes. Association of the genotypes was estimated against breast cancer risk, breast cancer–specific survival, and survival in different treatment groups, and clinicopathological variables. SNPs in TMPRSS3 (rs3814903 and rs11203200), TMPRSS7 (rs1844925), and HGF (rs5745752) associated significantly with breast cancer risk (P _trend = 0.008–0.042). SNPs in TMPRSS1 (rs12151195 and rs12461158), TMPRSS2 (rs2276205), TMPRSS3 (rs3814903), and TMPRSS7 (rs2399403) associated with prognosis (P = 0.004–0.046). When estimating the combined effect of the variants, the risk of breast cancer was higher with 4–5 alleles present compared to 0–2 alleles (P = 0.0001; OR, 2.34; 95% CI, 1.39–3.94). Women with 6–8 survival-associating alleles had a 3.3 times higher risk of dying of breast cancer compared to women with 1–3 alleles (P = 0.001; HR, 3.30; 95% CI, 1.58–6.88). The results demonstrate the combined effect of variants in TTSPs and their related genes in breast cancer risk and patient outcome. Functional analysis of these variants will lead to further understanding of this gene family, which may improve individualized risk estimation and development of new strategies for treatment of breast cancer.     

Polarized transport of Alzheimer amyloid precursor protein is mediated by adaptor protein complex AP1-1B

Alzheimer amyloid precursor protein (APP) is the precursor for the Abeta peptide involved in pathogenesis of Alzheimer's disease. The soluble ectodomain fragment of APP (sAPP) functions as a growth factor for epithelial cells, suggesting an important function for APP outside neuronal tissue. Previous studies have shown that in polarized epithelial cells, APP is targeted to the basolateral domain. Tyr653 within the cytoplasmic tail of APP mediates the basolateral targeting of APP, but the sorting machinery that binds to this residue has largely remained unknown. In this study, we analyzed the role of adaptor complexes in the polarized sorting of APP. We show that the medium subunit mu1B of the epithelia-specific adaptor protein (AP)-1B binds onto the cytoplasmic tail of APP in a Tyr653-dependent way. Moreover, ectopic expression of mu1B in cells lacking AP-1B resulted in correction of apical missorting of wild-type but not Tyr653Ala APP. Basolateral secretion of sAPP was found to be independent of Tyr653. We propose a model for polarized targeting of APP according to which sorting of APP to basolateral domain is dependent on binding of AP-1B on Tyr653 in basolateral endosomes. This model is in accordance with the current understanding of sorting mechanisms mediating polarized targeting of membrane proteins.     

Genome-Wide Association Study of Late-Onset Myasthenia Gravis: Confirmation of TNFRSF11A and Identification of ZBTB10 and Three Distinct HLA Associations

To investigate the genetics of late-onset myasthenia gravis (LOMG), we conducted a genome-wide association study imputation of >6 million single nucleotide polymorphisms (SNPs) in 532 LOMG cases (anti–acetylcholine receptor [AChR] antibody positive; onset age ≥50 years) and 2,128 controls matched for sex and population substructure. The data confirm reported TNFRSF11A associations (rs4574025, P = 3.9 × 10⁻⁷, odds ratio [OR] 1.42) and identify a novel candidate gene, ZBTB10, achieving genome-wide significance (rs6998967, P = 8.9 × 10⁻¹⁰, OR 0.53). Several other SNPs showed suggestive significance including rs2476601 (P = 6.5 × 10⁻⁶, OR 1.62) encoding the PTPN22 R620W variant noted in early-onset myasthenia gravis (EOMG) and other autoimmune diseases. In contrast, EOMG-associated SNPs in TNIP1 showed no association in LOMG, nor did other loci suggested for EOMG. Many SNPs within the major histocompatibility complex (MHC) region showed strong associations in LOMG, but with smaller effect sizes than in EOMG (highest OR ~2 versus ~6 in EOMG). Moreover, the strongest associations were in opposite directions from EOMG, including an OR of 0.54 for DQA1*05:01 in LOMG (P = 5.9 × 10⁻¹²) versus 2.82 in EOMG (P = 3.86 × 10⁻⁴⁵). Association and conditioning studies for the MHC region showed three distinct and largely independent association peaks for LOMG corresponding to (a) MHC class II (highest attenuation when conditioning on DQA1), (b) HLA-A and (c) MHC class III SNPs. Conditioning studies of human leukocyte antigen (HLA) amino acid residues also suggest potential functional correlates. Together, these findings emphasize the value of subgrouping myasthenia gravis patients for clinical and basic investigations and imply distinct predisposing mechanisms in LOMG.     

Flotillin-1/reggie-2 protein plays dual role in activation of receptor-tyrosine kinase/mitogen-activated protein kinase signaling

Our previous work has shown that the membrane microdomain-associated flotillin proteins are potentially involved in epidermal growth factor (EGF) receptor signaling. Here we show that knockdown of flotillin-1/reggie-2 results in reduced EGF-induced phosphorylation of specific tyrosines in the EGF receptor (EGFR) and in inefficient activation of the downstream mitogen-activated protein (MAP) kinase and Akt signaling. Although flotillin-1 has been implicated in endocytosis, its depletion affects neither the endocytosis nor the ubiquitination of the EGFR. However, EGF-induced clustering of EGFR at the cell surface is altered in cells lacking flotillin-1. Furthermore, we show that flotillins form molecular complexes with EGFR in an EGF/EGFR kinase-independent manner. However, knockdown of flotillin-1 appears to affect the activation of the downstream MAP kinase signaling more directly. We here show that flotillin-1 forms a complex with CRAF, MEK1, ERK, and KSR1 (kinase suppressor of RAS) and that flotillin-1 knockdown leads to a direct inactivation of ERK1/2. Thus, flotillin-1 plays a direct role during both the early phase (activation of the receptor) and late (activation of MAP kinases) phase of growth factor signaling. Our results here unveil a novel role for flotillin-1 as a scaffolding factor in the regulation of classical MAP kinase signaling. Furthermore, our results imply that other receptor-tyrosine kinases may also rely on flotillin-1 upon activation, thus suggesting a general role for flotillin-1 as a novel factor in receptor-tyrosine kinase/MAP kinase signaling.     

Electron paramagnetic resonance (EPR) spectroscopy characterization of wheat grains from plants of different water stress tolerance

Grains of five genotypes of wheat (four Polish and one Finnish), differing in their tolerance to drought stress were chosen for this investigation. Electron paramagnetic resonance spectroscopy allowed observation of transition metal ions (Mn, Fe, Cu) and different types of stable radicals, including semiquinone centers, present in seed coats, as well as several types of carbohydrate radicals found mainly in the inner parts of grains. The content of paramagnetic metal centers was higher in sensitive genotypes (Radunia, Raweta) than in tolerant ones (Parabola, Nawra), whereas the Finnish genotype (Manu) exhibited intermediate amounts. Similarly, the concentrations of both types of radicals, carbohydrates and semiquinone were significantly higher in the grains originating from more sensitive wheat genotypes. The nature of carbohydrate radicals and their concentrations were confronted with the kinds and amounts of sugars found by the biochemical analyses and microscopy observations. It is suggested that some long lived radicals (semiquinone and starch radicals) occurring in grains could be indicators of stress resistance of wheat plants.     

Associations of instrumental activities of daily living and handgrip strength with oral self-care among home-dwelling elderly 75+

doi: 10.1111/j.1741‐2358.2010.00427.x Associations of instrumental activities of daily living and handgrip strength with oral self‐care among home‐dwelling elderly 75+ Objective: To study the associations of instrumental activities of daily living (IADL) and the handgrip strength with oral self‐care among dentate home‐dwelling elderly people in Finland. Materials and methods: The study analysed data for 168 dentate participants (mean age 80.6 years) in the population‐based Geriatric Multidisciplinary Strategy for Good Care of the Elderly (GeMS) study. Each participant received a clinical oral examination and structured interview in 2004–2005. Functional status was assessed using the IADL scale and handgrip strength was measured using handheld dynamometry. Results: Study participants with high IADL (scores 7–8) had odds ratios (ORs) for brushing their teeth at least twice a day of 2.7 [95% confidence intervals (CI) 1.1–6.8], for using toothpaste at least twice a day of 2.0 (CI 0.8–5.2) and for having good oral hygiene of 2.8 (CI 1.0–8.3) when compared with participants with low IADL (scores ≤6). Participants in the upper tertiles of the handgrip strength had ORs for brushing the teeth at least twice a day of 0.9 (CI 0.4–1.9), for using the toothpaste at least twice a day of 0.9 (CI 0.4–1.8) and for good oral hygiene of 1.1 (CI 0.5–2.4) in comparison with the study subjects in the lowest tertile of handgrip strength. Conclusion: The results of this study suggest that the functional status, measured by means of the IADL scale, but not handgrip strength, is an important determinant of oral self‐care among the home‐dwelling elderly.     

Gli3-mediated somitic Fgf10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes

Little is known about the regulation of cell fate decisions that lead to the formation of five pairs of mammary placodes in the surface ectoderm of the mouse embryo. We have previously shown that fibroblast growth factor 10 (FGF10) is required for the formation of mammary placodes 1, 2, 3 and 5. Here, we have found that Fgf10 is expressed only in the somites underlying placodes 2 and 3, in gradients across and within these somites. To test whether somitic FGF10 is required for the formation of these two placodes, we analyzed a number of mutants with different perturbations of somitic Fgf10 gradients for the presence of WNT signals and ectodermal multilayering, markers for mammary line and placode formation. The mammary line is displaced dorsally, and formation of placode 3 is impaired in Pax3ILZ/ILZ mutants, which do not form ventral somitic buds. Mammary line formation is impaired and placode 3 is absent in Gli3Xt-J/Xt-J and hypomorphic Fgf10 mutants, in which the somitic Fgf10 gradient is shortened dorsally and less overall Fgf10 is expressed, respectively. Recombinant FGF10 rescued mammogenesis in Fgf10(-/-) and Gli3Xt-J/Xt-J flanks. We correlate increasing levels of somitic FGF10 with progressive maturation of the surface ectoderm, and show that full expression of somitic Fgf10, co-regulated by GLI3, is required for the anteroposterior pattern in which the flank ectoderm acquires a mammary epithelial identity. We propose that the intra-somitic Fgf10 gradient, together with ventral elongation of the somites, determines the correct dorsoventral position of mammary epithelium along the flank.     

Sleep Restriction Increases the Risk of Developing Cardiovascular Diseases by Augmenting Proinflammatory Responses through IL-17 and CRP

Background

Sleep restriction, leading to deprivation of sleep, is common in modern 24-h societies and is associated with the development of health problems including cardiovascular diseases. Our objective was to investigate the immunological effects of prolonged sleep restriction and subsequent recovery sleep, by simulating a working week and following recovery weekend in a laboratory environment.

Methods and Findings

After 2 baseline nights of 8 hours time in bed (TIB), 13 healthy young men had only 4 hours TIB per night for 5 nights, followed by 2 recovery nights with 8 hours TIB. 6 control subjects had 8 hours TIB per night throughout the experiment. Heart rate, blood pressure, salivary cortisol and serum C-reactive protein (CRP) were measured after the baseline (BL), sleep restriction (SR) and recovery (REC) period. Peripheral blood mononuclear cells (PBMC) were collected at these time points, counted and stimulated with PHA. Cell proliferation was analyzed by thymidine incorporation and cytokine production by ELISA and RT-PCR. CRP was increased after SR (145% of BL; p<0.05), and continued to increase after REC (231% of BL; p<0.05). Heart rate was increased after REC (108% of BL; p<0.05). The amount of circulating NK-cells decreased (65% of BL; p<0.005) and the amount of B-cells increased (121% of BL; p<0.005) after SR, but these cell numbers recovered almost completely during REC. Proliferation of stimulated PBMC increased after SR (233% of BL; p<0.05), accompanied by increased production of IL-1β (137% of BL; p<0.05), IL-6 (163% of BL; p<0.05) and IL-17 (138% of BL; p<0.05) at mRNA level. After REC, IL-17 was still increased at the protein level (119% of BL; p<0.05).

Conclusions

5 nights of sleep restriction increased lymphocyte activation and the production of proinflammatory cytokines including IL-1β IL-6 and IL-17; they remained elevated after 2 nights of recovery sleep, accompanied by increased heart rate and serum CRP, 2 important risk factors for cardiovascular diseases. Therefore, long-term sleep restriction may lead to persistent changes in the immune system and the increased production of IL-17 together with CRP may increase the risk of developing cardiovascular diseases.     

Primate-specific evolution of noncoding element insertion into PLA2G4C and human preterm birth

Background

The use of biological annotation such as genes and pathways in the analysis of gene expression data has aided the identification of genes for follow-up studies and suggested functional information to uncharacterized genes. Several studies have applied similar methods to genome wide association studies and identified a number of disease related pathways. However, many questions remain on how to best approach this problem, such as whether there is a need to obtain a score to summarize association evidence at the gene level, and whether a pathway, dominated by just a few highly significant genes, is of interest.

Methods

We evaluated the performance of two pathway-based methods (Random Set, and Binomial approximation to the hypergeometric test) based on their applications to three data sets of Crohn's disease. We consider both the disease status as a phenotype as well as the residuals after conditioning on IL23R, a known Crohn's related gene, as a phenotype.

Results

Our results show that Random Set method has the most power to identify disease related pathways. We confirm previously reported disease related pathways and provide evidence for IL-2 Receptor Beta Chain in T cell Activation and IL-9 signaling as Crohn's disease associated pathways.

Conclusions

Our results highlight the need to apply powerful gene score methods prior to pathway enrichment tests, and that controlling for genes that attain genome wide significance enable further biological insight.     

Collagen XVIII,a basement membrane heparan sulfate proteoglycan,interacts with L-selectin and monocyte chemoattractant protein-1

Leukocyte infiltration during inflammation is mediated by the sequential actions of adhesion molecules and chemokines. By using a rat ureteral obstruction model, we showed previously that L-selectin plays an important role in leukocyte infiltration into the kidney. Here we report the purification, identification, and characterization of an L-selectin-binding heparan sulfate proteoglycan (HSPG) expressed in the rat kidney. Partial amino acid sequencing and Western blotting analyses showed that the L-selectin-binding HSPG is collagen XVIII, a basement membrane HSPG. The binding of L-selectin to isolated collagen XVIII was specifically inhibited by an anti-L-selectin monoclonal antibody, EDTA, treatment of the collagen XVIII with heparitinase or heparin but not by chemically desulfated heparin. A cell binding assay showed that the L-selectin-collagen XVIII interaction mediates cell adhesion. Interestingly, collagen XVIII also interacted with a chemokine, monocyte chemoattractant protein-1, and presented it to a monocytic cell line, THP-1, which enhanced the alpha(4)beta(1) integrin-mediated binding of the THP-1 cells to vascular cell adhesion molecule-1. Thus, collagen XVIII may provide a link between selectin-mediated cell adhesion and chemokine-induced cellular activation and accelerate the progression of leukocyte infiltration in renal inflammation.