The hypoxia response and nutritional peptides.

Hypoxia controls metabolism at several levels, e.g., via mitochondrial ATP production, glucose uptake and glycolysis. Hence it is likely that hypoxia also affects the action and/or production of many peptide hormones linked to food intake and appetite control. Many of those are produced in the gastrointestinal tract, endocrine pancreas, adipose tissue, and selective areas in the brain which modulate and concert their actions. However, the complexity of the hypoxia response and the links to peptides/hormones involved in food intake and appetite control in the different organs are not well known. This review summarizes the role of the hypoxia response and its effects on major peptides linked to appetite regulation, nutrition and metabolism.

Bladder Cancer Survival of Men Receiving 5α-Reductase Inhibitors.

PURPOSE: Androgens may have a role in bladder carcinogenesis. We studied whether 5α-reductase inhibitors were associated with bladder cancer specific mortality in a population based cohort of men with bladder cancer. MATERIALS AND METHODS: The study cohort consisted of 10,720 Finnish men with bladder cancer newly diagnosed in 1997 to 2012 who were identified in a national cancer registry. Median followup was 4.17 years after bladder cancer diagnosis. We analyzed the HR and 95% CI of the risk of bladder cancer death by 5α-reductase inhibitor administration using Cox regression adjusted for age, gender, comorbidities, primary bladder cancer treatment and tumor extent at diagnosis. Lag time analyses were performed to assess the long-term risk association. Simultaneous administration α-blockers was considered to estimate possible confounding by indication. RESULTS: Administering 5α-reductase inhibitors before bladder cancer diagnosis was associated with a lower risk of bladder cancer death (HR 0.84, 95% CI 0.73-0.97). The risk decrease became stronger with years of use. Conversely prediagnostic administration of α-blockers was not associated with bladder cancer survival (HR 1.02, 95% CI 0.91-1.13). Similarly 5α-reductase inhibitor administration after diagnosis was associated with a decreased risk of bladder cancer death (HR 0.77, 95% CI 0.68-0.88). Bladder cancer survival was not associated with α-blockers (HR 0.98, 95% CI 0.90-1.07). The risk decrease due to 5α-reductase inhibitors persisted up to 5 years. CONCLUSIONS: Patients who receive 5α-reductase inhibitors have improved disease specific survival after bladder cancer diagnosis compared to those who do not receive them while α-blockers were not associated with survival. This supports the benefits of 5α-reductase inhibitors in bladder cancer.

Neurofibromatosis type 1 gene mutation analysis using sequence capture and high-throughput sequencing.

Neurofibromatosis type 1 syndrome (NF1) is caused by mutations in the NF1 gene. Availability of new sequencing technology prompted us to search for an alternative method for NF1 mutation analysis. Genomic DNA was isolated from saliva avoiding invasive sampling. The NF1 exons with an additional 50bp of flanking intronic sequences were captured and enriched using the SeqCap EZ Choice Library protocol. The captured DNA was sequenced with the Roche/454 GS Junior system. The mean coverages of the targeted regions were 41x and 74x in 2 separate sets of samples. An NF1 mutation was discovered in 10 out of 16 separate patient samples. Our study provides proof of principle that the sequence capture methodology combined with high-throughput sequencing is applicable to NF1 mutation analysis. Deep intronic mutations may however remain undetectable, and change at the DNA level may not predict the outcome at the mRNA or protein levels.

Identification of MAMDC1 as a candidate susceptibility gene for systemic lupus erythematosus (SLE).

BACKGROUND: Systemic lupus erythematosus (SLE) is a complex autoimmune disorder with multiple susceptibility genes. We have previously reported suggestive linkage to the chromosomal region 14q21-q23 in Finnish SLE families. PRINCIPAL FINDINGS: Genetic fine mapping of this region in the same family material, together with a large collection of parent affected trios from UK and two independent case-control cohorts from Finland and Sweden, indicated that a novel uncharacterized gene, MAMDC1 (MAM domain containing glycosylphosphatidylinositol anchor 2, also known as MDGA2, MIM 611128), represents a putative susceptibility gene for SLE. In a combined analysis of the whole dataset, significant evidence of association was detected for the MAMDC1 intronic single nucleotide polymorphisms (SNP) rs961616 (P -value = 0.001, Odds Ratio (OR) = 1.292, 95% CI 1.103-1.513) and rs2297926 (P -value = 0.003, OR = 1.349, 95% CI 1.109-1.640). By Northern blot, real-time PCR (qRT-PCR) and immunohistochemical (IHC) analyses, we show that MAMDC1 is expressed in several tissues and cell types, and that the corresponding mRNA is up-regulated by the pro-inflammatory cytokines tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) in THP-1 monocytes. Based on its homology to known proteins with similar structure, MAMDC1 appears to be a novel member of the adhesion molecules of the immunoglobulin superfamily (IgCAM), which is involved in cell adhesion, migration, and recruitment to inflammatory sites. Remarkably, some IgCAMs have been shown to interact with ITGAM, the product of another SLE susceptibility gene recently discovered in two independent genome wide association (GWA) scans. SIGNIFICANCE: Further studies focused on MAMDC1 and other molecules involved in these pathways might thus provide new insight into the pathogenesis of SLE.

Large-scale zygosity testing using single nucleotide polymorphisms.

A requirement for performing robust genetic and statistical analyses on twins is correctly assigned zygosities. In order to increase the power to detect small risk factors of disease, zygosity testing should also be amenable for high throughput screening. In this study we validate and implement the use of a panel of 50 single nucleotide polymorphisms (SNPs) for reliable high throughput zygosity testing and compare it to a panel of 16 short tandem repeats (STRs). We genotyped both genomic (gDNA) and whole genome amplified DNA (WGA DNA), ending up with 47 SNP and 11 STR markers fulfilling our quality criteria. Out of 99 studied twin pairs, 2 were assigned a different zygosity using SNP and STR data as compared to self reported zygosity in a questionnaire. We also performed a sensitivity analysis based on simulated data where we evaluated the effects of genotyping error, shifts in allele frequencies and missing data on the qualitative zygosity assignments. The frequency of false positives was less than 0.01 when assuming a 1% genotyping error, a decrease of 10% of the observed minor allele frequency compared to the actual values and up to 10 missing markers. The SNP markers were also successfully genotyped on both gDNA and WGA DNA from whole blood, saliva and filter paper. In conclusion, we validate a robust panel of 47 highly multiplexed SNPs that provide reliable and high quality data on a range of different DNA templates.

Fraser syndrome and mouse blebbed phenotype caused by mutations in FRAS1/Fras1 encoding a putative extracellular matrix protein.

Fraser syndrome (OMIM 219000) is a multisystem malformation usually comprising cryptophthalmos, syndactyly and renal defects. Here we report autozygosity mapping and show that the locus FS1 at chromosome 4q21 is associated with Fraser syndrome, although the condition is genetically heterogeneous. Mutation analysis identified five frameshift mutations in FRAS1, which encodes one member of a family of novel proteins related to an extracellular matrix (ECM) blastocoelar protein found in sea urchin. The FRAS1 protein contains a series of N-terminal cysteine-rich repeat motifs previously implicated in BMP metabolism, suggesting that it has a role in both structure and signal propagation in the ECM. It has been speculated that Fraser syndrome is a human equivalent of the blebbed phenotype in the mouse, which has been associated with mutations in at least five loci including bl. As mapping data were consistent with homology of FRAS1 and bl, we screened DNA from bl/bl mice and identified a premature termination of mouse Fras1. Thus, the bl mouse is a model for Fraser syndrome in humans, a disorder caused by disrupted epithelial integrity in utero.