CYLD mutations in familial skin appendage tumours

Background: Germ-line mutations in CYLD are found in patients with familial skin appendage tumours. The protein product functions as a deubiquitinase enzyme, which negatively regulates NF-kappa B and c-Jun N-terminal kinase signalling. Brooke-Spiegler syndrome (BSS) is characterised by cylindromas, trichoepitheliomas and spiradenomas, whereas in familial cylindromatosis (FC) patients present with cylindromas and in multiple familial trichoepitheliomas (MFT) with trichoepitheliomas as the only skin tumour type. Although described as distinct entities, recent studies suggest that they are within the spectrum of a single entity. Objective: To investigate the mutation spectrum of CYLD and possible genotype-phenotype correlations. Methods: 25 families including 13 BSS, 3 FC, and 9 MFT families were examined and evaluated for mutations in the CYLD gene. Results: In total, 18 mutations in CYLD, including 6 novel mutations, were identified in 25 probands (72%). The mutation frequencies among distinct phenotypes were 85% for BSS, 100% for FC, and 44% for MFT. The majority of the mutations were insertions, deletions or nonsense mutations leading to formation of truncated proteins. All mutations were located between exons 9 to 20, encoding the NEMO binding site and the catalytic domain. Genotype-phenotype analysis failed to reveal a correlation between the types of mutations and their location within the gene and the patients` phenotypes and disease severity. Conclusions: This study provides further evidence on the role of CYLD in the pathogenesis of skin appendage tumours characterised by cylindromas, trichoepitheliomas and/or spiradenomas, but the molecular mechanisms of CYLD in skin tumorigenesis and the reasons for phenotypic variability remain to be explored.

The common-866G > A variant in the promoter of UCP2 is associated with decreased risk of coronary artery disease in type 2 diabetic men

OBJECTIVE-Uncoupling protein 2 (UCP2) is a physiological downregulator of reactive oxygen species generation and plays an antiatherogenic role in the vascular wall. A common variant in the UCP2 promoter (-866G>A) modulates mRNA expression, with increased expression associated with the A allele. We investigated association of this variant with coronary artery disease (CAD) in two cohorts of type 2 diabetic subjects. RESEARCH DESIGN AND METHODS-We studied 3,122 subjects from the 6-year prospective Non-Insulin-Dependent Diabetes, Hypertension, Microalbuminuria, Cardiovascular Events, and Ramipril (DIABHYCAR) Study (14.9% of CAD incidence at follow-up). An independent, hospital-based cohort of 335 men, 52% of whom had CAD, was also studied. RESULTS-We observed an inverse association of the A allele with incident cases of CAD in a dominant model (hazard risk 0.88 [95% CI 0.80-0.96]; P = 0.006). Similar results were observed for baseline cases of CAD. Stratification by sex confirmed an allelic association with CAD in men, whereas no association was observed in women. All CAD phenotypes considered-myocardial infarction, angina pectoris, coronary artery bypass graft (CABG), and sudden death-contributed significantly to the association. Results were replicated in a cross-sectional study of an independent cohort (odds ratio 0.47 [95% CI 0.25-0.89]; P = 0.02 for a recessive model). CONCLUSIONS-The A allele of the -866G>A variant of UCP2 was associated with reduced risk of CAD in men with type 2 diabetes in a 6-year prospective study. Decreased risk of myocardial infarction, angina pectoris, CABG, and sudden death contributed individually and significantly to the reduction of CAD risk. This association was independent of other common CAD risk factors.

Human mucosal leishmaniasis: Neutrophils infiltrate areas of tissue damage that express high levels of Th17-related cytokines

Mucosal leishmaniasis (ML) is characterised by severe tissue destruction. Herein, we evaluated the involvement of the IL-17-type response in the inflammatory infiltrate of biopsy specimens from 17 ML patients. IL-17 and IL-17-inducing cytokines (IL-1 beta, IL-23, IL-6 and TGF-beta) were detected by immunohistochemistry in ML patients. IL-17(+) cells exhibited CD4(+), CD8(+) or CD14(+) phenotypes, and numerous IL-17(+) cells co-expressed the CC chemokine receptor 6 (CCR6). Neutrophils, a hallmark of Th17-mediated inflammation, were regularly detected in necrotic and perinecrotic areas and stained positive for neutrophil elastase, myeloperoxidase and MMP-9. Taken together, these observations demonstrate the existence of Th17 cells in ML lesions associated with neutrophils in areas of tissue injury and suggest that IL-17 is involved in ML pathogenesis.

Mouse Leydig cells express multiple P2X receptor subunits

ATP acts on cellular membranes by interacting with P2X (ionotropic) and P2Y (metabotropic) receptors. Seven homomeric P2X receptors (P2X(1)-P2X(7)) and seven heteromeric receptors (P2X(1/2), P2X(1/4), P2X(1/5), P2X(2/3), P2X(2/6), P2X(4/6), P2X(4/7)) have been described. ATP treatment of Leydig cells leads to an increase in [Ca(2+)](i) and testosterone secretion, supporting the hypothesis that Ca(2+) signaling through purinergic receptors contributes to the process of testosterone secretion in these cells. Mouse Leydig cells have P2X receptors with a pharmacological and biophysical profile resembling P2X(2). In this work, we describe the presence of several P2X receptor subunits in mouse Leydig cells. Western blot experiments showed the presence of P2X(2), P2X(4), P2X(6), and P2X(7) subunits. These results were confirmed by immunofluorescence. Functional results support the hypothesis that heteromeric receptors are present in these cells since 0.5 mu M ivermectin induced an increase (131.2 +/- 5.9%) and 3 mu M ivermectin a decrease (64.2 +/- 4.8%) in the whole-cell currents evoked by ATP. These results indicate the presence of functional P2X(4) subunits. P2X(7) receptors were also present, but they were non-functional under the present conditions because dye uptake experiments with Lucifer yellow and ethidium bromide were negative. We conclude that a heteromeric channel, possibly P2X(2/4/6), is present in Leydig cells, but with an electrophysiological and pharmacological phenotype characteristic of the P2X(2) subunit.

The insulin signaling pathway in honey bee (Apis mellifera) caste development - differential expression of insulin-like peptides and insulin receptors in queen and worker larvae

The insulin/insulin-like signaling (IIS) pathway is an evolutionarily conserved module in the control of body size and correlated organ growth in metazoans. In the highly eusocial bees, the caste phenotypes differ not only in size and several structural features but also in individual fitness and life history. We investigated the developmental expression profiles of genes encoding the two insulin-like peptides (AmILP-1 and AmILP-2) and the two insulin receptors (AmInR-1 and AmInR-2) predicted in the honey bee genome. Quantitative PCR analysis for queen and worker larvae in critical stages of caste development showed that AmILP-2 is the predominantly transcribed ILP in both castes, with higher expression in workers than in queens. Expression of both InR genes sharply declined in fourth instar queen larvae, but showed little modulation in workers. On first sight, these findings are non-intuitive, considering the higher growth rates of queens, but they can be interpreted as possibly antagonistic crosstalk between the IIS module and juvenile hormone. Analyzing AmInR-1 and AmInR-2 expression in ovaries of queen and worker larvae revealed low transcript levels in queens and a sharp drop in AmInR-2 expression in fifth instar worker larvae, indicating relative independence in tissue-specific versus overall IIS pathway activity. (C) 2008 Elsevier Ltd. All rights reserved.

Genetic Susceptibility Loci in Rheumatoid Arthritis Establish Transcriptional Regulatory Networks with Other Genes

Linkage studies have identified the human leukocyte antigen (HLA)-DRB1 as a putative rheumatoid arthritis (RA) susceptibility locus (SL). Nevertheless, it was estimated that its contribution was partial, suggesting that other non-HLA genes may play a role in RA susceptibility. To test this hypothesis, we conducted microarray transcription profiling of peripheral blood mononuclear cells in 15 RA patients and analyzed the data, using bioinformatics programs (significance analysis of microarrays method and GeneNetwork), which allowed us to determine the differentially expressed genes and to reconstruct transcriptional networks. The patients were grouped according to disease features or treatment with tumor necrosis factor blocker. Transcriptional networks that were reconstructed allowed us to identify the interactions occurring between RA SL and other genes, for example, HLA-DRB1 interacting with FNDC3A (fibronectin type III domain containing 3A). Given that fibronectin fragments can stimulate mediators of matrix and cartilage destruction in RA, this interaction is of special interest and may contribute to a clearer understanding of the functional role of HLA-DRB1 in RA pathogenesis.

Multipotent mesenchymal stromal cells obtained from diverse human tissues share functional properties and gene-expression profile with CD146(+) perivascular cells and fibroblasts

Objective. The relationship of multipotent mesenchymal stromal cells (MSC) with pericytes and fibroblasts has not been established thus far, although they share many markers of primitive marrow stromal cells and the osteogenic, adipogenic, and chondrogenic differentiation potentials. Materials and Methods. We compared MSCs from adult or fetal tissues, MSC differentiated in vitro, fibroblasts and cultures of retinal pericytes obtained either by separation with anti-CD146 or adhesion. The characterizations included morphological, immunophenotypic, gene-expression profile, and differentiation potential. Results. Osteogenic, adipocytic, and chondrocytic differentiation was demonstrated for MSC, retinal perivascular cells, and fibroblasts. Cell morphology and the phenotypes defined by 22 markers were very similar. Analysis of the global gene expression obtained by serial analysis of gene expression for 17 libraries and by reverse transcription polymerase chain reaction of 39 selected genes from 31 different cell cultures, revealed similarities among MSC, retinal perivascular cells, and hepatic stellate cells. Despite this overall similarity, there was a heterogeneous expression of genes related to angiogenesis, in MSC derived from veins, artery, perivascular cells, and fibroblasts. Evaluation of typical pericyte and MSC transcripts, such as NG2, CD146, CD271, and CD140B on CD146 selected perivascular cells and MSC by real-time polymerase chain reaction confirm the relationship between these two cell types. Furthermore, the inverse correlation between fibroblast-specific protein-1 and CD146 transcripts observed on pericytes, MSC, and fibroblasts highlight their potential use as markers of this differentiation pathway. Conclusion. Our results indicate that human MSC and pericytes are similar cells located in the wall of the vasculature, where they function as cell sources for repair and tissue maintenance, whereas fibroblasts are more differentiated cells with more restricted differentiation potential. (C) 2008 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.

TAC3/TACR3 Mutations Reveal Preferential Activation of Gonadotropin-Releasing Hormone Release by Neurokinin B in Neonatal Life Followed by Reversal in Adulthood

Context: Mutations in TAC3 and TACR3 (encoding neurokinin B and its receptor) have been identified in Turkish patients with idiopathic hypogonadotropic hypogonadism (IHH), but broader populations have not yet been tested and genotype-phenotype correlations have not been established. Objective: A broad cohort of normosmic IHH probands was screened for mutations in TAC3/TACR3 to evaluate the prevalence of such mutations and define the genotype/phenotype relationships. Design and Setting: The study consisted of sequencing of TAC3/TACR3, in vitro functional assays, and neuroendocrine phenotyping conducted in tertiary care centers worldwide. Patients or Other Participants: 345 probands, 18 family members, and 292 controls were studied. Intervention: Reproductive phenotypes throughout reproductive life and before and after therapy were examined. Main Outcome Measure: Rare sequence variants in TAC3/TACR3 were detected. Results: In TACR3, 19 probands harbored 13 distinct coding sequence rare nucleotide variants [three nonsense mutations, six nonsynonymous, four synonymous (one predicted to affect splicing)]. In TAC3, one homozygous single base pair deletion was identified, resulting in complete loss of the neurokinin B decapeptide. Phenotypic information was available on 16 males and seven females with coding sequence variants in TACR3/TAC3. Of the 16 males, 15 had microphallus; none of the females had spontaneous thelarche. Seven of the 16 males and five of the seven females were assessed after discontinuation of therapy; six of the seven males and four of the five females demonstrated evidence for reversibility of their hypogonadotropism. Conclusions: Mutations in the neurokinin B pathway are relatively common as causes of hypogonadism. Although the neurokinin B pathway appears essential during early sexual development, its importance in sustaining the integrity of the hypothalamic-pituitary-gonadal axis appears attenuated over time. (J Clin Endocrinol Metab 95: 2857-2867, 2010)

Risk of Potential Drug-Drug Interactions among Brazilian Elderly A Population-Based, Cross-Sectional Study

Background: Drug-drug interactions (DDIs) are one of the main causes of adverse reactions related to medications, being responsible for up to 23% of hospital admissions. However, only a few studies have evaluated this problem in elderly Brazilians. Objectives: To determine the prevalence of potential DDIs (PDDIs) in community-dwelling elderly people in Brazil, analyse these interactions with regard to severity and clinical implications, and identify associated factors. Methods: A population-based cross-sectional study was carried out involving 2143 elderly (aged 60 years) residents of the metropolitan area of Sao Paulo, Brazil. Data were obtained from the SABE (Saude, Bem estar e Envelhecimento [Health, Well-Being, and Aging]) survey, which is a multicentre study carried out in seven countries of Latin America and the Caribbean, coordinated by the Pan-American Health Organization. PDDIs were analysed using a computerized program and categorized according to level of severity, onset, mechanism and documentation in the literature. The STATA software statistical package was used for data analysis, and logistic regression was conducted to determine whether variables were associated with PDDIs. Results: Analysis revealed that 568 (26.5%) of the elderly population included in the study were taking medications that could lead to a DDI. Almost two-thirds (64.4%) of the elderly population exposed to PDDIs were women, 50.7% were aged >= 75 years, 71.7% reported having fair or poor health and 65.8% took 2-5 medications. A total of 125 different PDDIs were identified; the treatment combination of an ACE inhibitor with a thiazide or loop diuretic (associated with hypotension) was the most frequent cause of PDDIs (n=322 patients; 56.7% of individuals with PDDIs). Analysis of the PDDIs revealed that 70.4% were of moderate severity, 64.8% were supported by good quality evidence and 56.8% were considered of delayed onset. The multivariate analysis showed that the risk of a PDDI was significantly increased among elderly individuals using six or more medications (odds ratio [OR] 3.37) and in patients with hypertension (OR 2.56), diabetes mellitus (OR 1.73) or heart problems (OR 3.36). Conclusions: Approximately one-quarter of the elderly population living in Sao Paulo could be taking two or more potentially interacting medicines. Polypharmacy predisposes elderly individuals to PDDIs. More than half of these drug combinations (57.6%, n = 72) were part of commonly employed treatment regimens and may be responsible for adverse reactions that compromise the safety of elderly individuals, especially at home. Educational initiatives are needed to avoid unnecessary risks.

Multi-system neurological disease is common in patients with OPA1 mutations

Additional neurological features have recently been described in seven families transmitting pathogenic mutations in OPA1, the most common cause of autosomal dominant optic atrophy. However, the frequency of these syndromal `dominant optic atrophy plus` variants and the extent of neurological involvement have not been established. In this large multi-centre study of 104 patients from 45 independent families, including 60 new cases, we show that extra-ocular neurological complications are common in OPA1 disease, and affect up to 20% of all mutational carriers. Bilateral sensorineural deafness beginning in late childhood and early adulthood was a prominent manifestation, followed by a combination of ataxia, myopathy, peripheral neuropathy and progressive external ophthalmoplegia from the third decade of life onwards. We also identified novel clinical presentations with spastic paraparesis mimicking hereditary spastic paraplegia, and a multiple sclerosis-like illness. In contrast to initial reports, multi-system neurological disease was associated with all mutational subtypes, although there was an increased risk with missense mutations [odds ratio = 3.06, 95% confidence interval = 1.44-6.49; P = 0.0027], and mutations located within the guanosine triphosphate-ase region (odds ratio = 2.29, 95% confidence interval = 1.08-4.82; P = 0.0271). Histochemical and molecular characterization of skeletal muscle biopsies revealed the presence of cytochrome c oxidase-deficient fibres and multiple mitochondrial DNA deletions in the majority of patients harbouring OPA1 mutations, even in those with isolated optic nerve involvement. However, the cytochrome c oxidase-deficient load was over four times higher in the dominant optic atrophy + group compared to the pure optic neuropathy group, implicating a causal role for these secondary mitochondrial DNA defects in disease pathophysiology. Individuals with dominant optic atrophy plus phenotypes also had significantly worse visual outcomes, and careful surveillance is therefore mandatory to optimize the detection and management of neurological disability in a group of patients who already have significant visual impairment.

Characterizing the phenotypic manifestations of MFN2 R104W mutation in Charcot-Marie-Tooth type 2

Mutations of the mitofusin 2 (MFN2) gene have been reported to be the most common cause of the axonal form of Charcot Marie Tooth disease (CMT). The aim of this study was to describe a de novo MFN2 p.R104W mutation and characterize the associated phenotype. We screened the entire coding region of MFN2 gene and characterized its clinical phenotype, nerve conduction studies and sural nerve biopsy. Neuropsychological tests and brain MRI were also performed. A de nova mutation was found in exon 4 (c.310C > T; p.R104W). In addition to a severe and early onset axonal neuropathy, the patient presented learning problems, obesity, glucose intolerance, leukoencephalopathy, brain atrophy and evidence of myelin involvement and mitochondrial structural changes on sural nerve biopsy. These results suggest that MFN2 p.R104W mutation is as a hot-spot for MFN2 gene associated to a large and complex range of phenotypes. (C) 2011 Elsevier B.V. All rights reserved.

Determination of P-glycoprotein, MDR-related protein 1, breast cancer resistance protein, and lung-resistance protein expression in leukemic stem cells of acute myeloid leukemia

Background: The most primitive leukemic precursor in acute myeloid leukemia (AML) is thought to be the leukemic stem cell (LSC), which retains the properties of self-renewal and high proliferative capacity and quiescence of the hematopoietic stem cell. LSC seems to be immunophenotypically distinct and more resistant to chemotherapy than the more committed blasts. Considering that the multidrug resistance (MDR) constitutive expression may be a barrier to therapy in AML, we have investigated whether various MDR transporters were differentially expressed at the protein level by different leukemic subsets. Methods: The relative expression of the drug-efflux pumps P-gp, MRP, LRP, and BCRP was evaluated by mean fluorescence index (MFI) and the Kolmogorov-Smirnov analysis (D values) in five leukemic subpopulations: CD34(+)CD38(-)CD123(+) (LSCs), CD34(+)CD38(+)CD123(-), CD34(+)CD38(+)CD123(+), CD34(+)CD38(+)CD123(-), and CD34(-) mature cells in 26 bone marrow samples of CD34(+) AML cases. Results: The comparison between the two more immature subsets (LSC versus CD34(+)CD38(-)CD123(-) cells) revealed a higher P-gp, MRP, and LRP expression in LSCs. The comparative analysis between LSCs and subsets of intermediate maturation (CD34(+)CD38(+)) demonstrated the higher BCRP expression in the LSCs. In addition, P-gp expression was also significantly higher in the LSC compared to CD34(+)CD38(+)CD123(-) subpopulation. Finally, the comparative analysis between LSC and the most mature subset (CD34(-)) revealed higher MRP and LRP and lower P-gp expression in the LSCs. Conclusions: Considering the cellular heterogeneity of AML, the higher MDR transporters expression at the most immature, self-renewable, and quiescent LSC population reinforces that MDR is one of the mechanisms responsible for treatment failure. (C) 2008 Clinical Cytometry Society.

5-HT2C receptor regulation of defensive responses in the rat dorsal periaqueductal gray

Activation of 5-HT2C receptors in limbic structures such as the amygdala and hippocampus increases anxiety. Indirect evidence obtained with non-selective 5-HT2C-interacting drugs suggests that the same may occur in the dPAG, a brainstem region consistently implicated in the genesis/regulation of panic attacks. In this study we used more selective agonists and antagonists to unveil the role played by dPAG 5-HT2C receptors in the regulation of anxiety- and panic-related defensive behaviors. Our results showed that intra-dPAG microinjection of the endogenous agonist 5-HT (20 nmol) or the 5-HT2C receptor agonists MK-212 (1 and 10 nmol) and RO-600175 (40 nmol) significantly increased inhibitory avoidance acquisition in rats tested in the elevated T-maze, suggesting an anxiogenic effect. 5-HT, but not the two 5-HT2C receptor agonists, inhibited escape performance. In the elevated T-maze, inhibitory avoidance and escape responses have been related to generalized anxiety and panic attacks, respectively. The behavioral effects caused by 5-HT and MK-212 were fully blocked by previous local microinjection of the 5-HT2C receptor antagonist SB-242084. Intra-dPAG injection of MK-212 also failed to affect escape expression in another test relating this behavior to panic, the electrical stimulation of the dPAG. Overall, the results indicate that 5-HT2C receptors in the dPAG are preferentially involved in the regulation of defensive behaviors related to anxiety, but not panic. This finding extends to the dPAG the prominent role that has been attributed to 5-HT2C receptors in anxiety generation. (C) 2010 Elsevier Ltd. All rights reserved.

Generation of Polyclonal Antibodies Against Recombinant Human Glucocerebrosidase Produced in Escherichia coli

Deficiency of the lysosomal glucocerebrosidase (GCR) enzyme results in Gaucher`s disease, the most common inherited storage disorder. Treatment consists of enzyme replacement therapy by the administration of recombinant GCR produced in Chinese hamster ovary cells. The production of anti-GCR antibodies has already been described with placenta-derived human GCR that requires successive chromatographic procedures. Here, we report a practical and efficient method to obtain anti-GCR polyclonal antibodies against recombinant GCR produced in Escherichia coli and further purified by a single step through nickel affinity chromatography. The purified GCR was used to immunize BALB/c mice and the induction of anti-GCR antibodies was evaluated by enzyme-linked immunosorbent assay. The specificity of the antiserum was also evaluated by western blot analysis against recombinant GCR produced by COS-7 cells or against endogenous GCR of human cell lines. GCR was strongly recognized by the produced antibodies, either as cell-associated or as secreted forms. The detected molecular masses of 59-66 kDa are in accordance to the expected size for glycosylated GCR. The GCR produced in E. coli would facilitate the production of polyclonal (shown here) and monoclonal antibodies and their use in the characterization of new biosimilar recombinant GCRs coming in the near future.

Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.