Myosin Va phosphorylated on ser(1650) is found in nuclear speckles and redistributes to nucleoli upon inhibition of transcription

Nuclear actin and nuclear myosins have been implicated in the regulation of geneexpression in vertebrate cells. Myosin V is a class of actin-based motor proteins involved in cytoplasmic vesicle transport and anchorage, spindle-pole alignment and mRNA translocation. In this study, myosin-Va, phosphorylated on a conserved serine in the tail domain (phospho-ser(1650) MVa), was localized to subnuclear compartments. A monoclonal antibody, 9E6, raised against a peptide corresponding to phosphoserine(1650) and flanking regions of the murine myosin Va sequence, was immunoreactive to myosin Va heavy chain in cellular and nuclear extracts of HeLa cells, PC12 cells and B16-F10 melanocytes. Immunofluorescence microscopy with this antibody revealed discrete irregular spots within the nucleoplasm that colocalized with SC35, a splicing factor that earmarks nuclear speckles. Phospho-ser(1650) MVa was not detected in other nuclear compartments, such as condensed chromatin, Cajal bodies, gems and perinucleolar caps. Although nucleoli also were not labeled by 9E6 under normal conditions, inhibition of transcription in HeLa cells by actinomycin D caused the redistribution of phospho-ser(1650) MVa to nucleoli, as well as separating a fraction of phosphoser(1650) MVa from SC35 into near-neighboring particles. These observations indicate a novel role for myosin Va in nuclear compartmentalization and offer a new lead towards the understanding of actomyosin-based gene regulation.

Gene expression profile analysis of primary glioblastomas and non-neoplastic brain tissue: identification of potential target genes by oligonucleotide microarray and real-time quantitative PCR

The prognosis of glioblastomas is still extremely poor and the discovery of novel molecular therapeutic targets can be important to optimize treatment strategies. Gene expression analyses comparing normal and neoplastic tissues have been used to identify genes associated with tumorigenesis and potential therapeutic targets. We have used this approach to identify differentially expressed genes between primary glioblastomas and non-neoplastic brain tissues. We selected 20 overexpressed genes related to cell cycle, cellular movement and growth, proliferation and cell-to-cell signaling and analyzed their expression levels by real time quantitative PCR in cDNA obtained from microdissected fresh tumor tissue from 20 patients with primary glioblastomas and from 10 samples of non-neoplastic white matter tissue. The gene expression levels were significantly higher in glioblastomas than in non-neoplastic white matter in 18 out of 20 genes analyzed: P < 0.00001 for CDKN2C, CKS2, EEF1A1, EMP3, PDPN, BNIP2, CA12, CD34, CDC42EP4, PPIE, SNAI2, GDF15 and MMP23b; and NFIA (P: 0.0001), GPS1 (P: 0.0003), LAMA1 (P: 0.002), STIM1 (P: 0.006), and TASP1 (P: 0.01). Five of these genes are located in contiguous loci at 1p31-36 and 2 at 17q24-25 and 8 of them encode surface membrane proteins. PDPN and CD34 protein expression were evaluated by immunohistochemistry and they showed concordance with the PCR results. The present results indicate the presence of 18 overexpressed genes in human primary glioblastomas that may play a significant role in the pathogenesis of these tumors and that deserve further functional investigation as attractive candidates for new therapeutic targets.

Identification of a myeloid committed progenitor as the cancer-initiating cell in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is characterized by a block in differentiation and accumulation of promyelocytes in the bone marrow and blood. The majority of APL patients harbor the t(15: 17) translocation leading to expression of the fusion protein promyelocytic-retinoic acid receptor alpha. Treatment with retinoic acid leads to degradation of promyelocytic-retinoic acid receptor alpha protein and disappearance of leukemic cells; however, 30% of APL patients relapse after treatment. One potential mechanism for relapse is the persistence of cancer ""stem"" cells in hematopoietic organs after treatment. Using a novel sorting strategy we developed to isolate murine myeloid cells at distinct stages of differentiation, we identified a population of committed myeloid cells (CD34(+), c-kit(+), Fc gamma RIII/II(+), Gr1(int)) that accumulates in the spleen and bone marrow in a murine model of APL. We observed that these cells are capable of efficiently generating leukemia in recipient mice, demonstrating that this population represents the APL cancer-initiating cell. These cells down-regulate the transcription factor CCAAT/enhancer binding protein alpha (C/EBP alpha) possibly through a methylation-dependent mechanism, indicating that C/EBP alpha deregulation contributes to transformation of APL cancer-initiating cells. Our findings provide further understanding of the biology of APL by demonstrating that a committed transformed progenitor can initiate and propagate the disease. (Blood. 2009; 114: 5415-5425)

Evidence for a network transcriptional control of promiscuous gene expression in medullary thymic epithelial cells

The expression of peripheral tissue antigens (PTAs) in the thymus by medullary thymic epithelial cells (mTECs) is essential for the central self-tolerance in the generation of the T cell repertoire. Due to heterogeneity of autoantigen representation, this phenomenon has been termed promiscuous gene expression (PGE), in which the autoimmune regulator (Aire) gene plays a key role as a transcription factor in part of these genes. Here we used a microarray strategy to access PGE in cultured murine CD80(+) 3.10 mTEC line. Hierarchical clustering of the data allowed observation that PTA genes were differentially expressed being possible to found their respective induced or repressed mRNAs. To further investigate the control of PGE, we tested the hypothesis that genes involved in this phenomenon might also be modulated by transcriptional network. We then reconstructed such network based on the microarray expression data, featuring the guanylate cyclase 2d (Gucy2d) gene as a main node. In such condition, we established 167 positive and negative interactions with downstream PTA genes. Silencing Aire by RNA interference, Gucy2d while down regulated established a larger number (355) of interactions with PTA genes. T- and G-boxes corresponding to AIRE protein binding sites located upstream to ATG codon of Gucy2d supports this effect. These findings provide evidence that Aire plays a role in association with Gucy2d, which is connected to Several PTA genes and establishes a cascade-like transcriptional control of promiscuous gene expression in mTEC cells. (C) 2009 Elsevier Ltd. All rights reserved.

Novel Mutations in CYP11B1 Gene Leading to 11 beta-Hydroxylase Deficiency in Brazilian Patients

Background: Deficiency of 11 beta-hydroxylase results in the impairment of the last step of cortisol synthesis. In females, the phenotype of this disorder includes different degrees of genital ambiguity and arterial hypertension. Mutations in the CYP11B1 gene are responsible for this disease. Objective: The objective of the study was to screen the CYP11B1 gene for mutations in two unrelated Brazilian females with congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency. Design: The coding and intron-exon junction regions of CYP11B1 were totally sequenced. A putative splice mutation was further investigated by minigene transcription. Results: We report two novel CYP11B1 mutations in these Brazilian patients. An Arabian Lebanese descendent female was found to be homozygous for a cytosine insertion at the beginning of exon 8, changing the 404 arginine to proline. It alters the open reading frame, creating a putative truncated protein at 421 residue, which eliminates the domain necessary for the association of heme prosthetic group. A severely virilized female was homozygous for the g. 2791G>A transition in the last position of exon 4. This nucleotide is also part of 5` intron 4 donor splice site consensus sequence. Minigene experiments demonstrated that g. 2791G>A activated an alternative splice site within exon 4, leading to a 45-bp deletion in the transcript. The putative translation of such modified mRNA indicates a truncated protein at residue 280. Conclusions: We describe two novel mutations, g. 4671_4672insC and g. 2791G>A, that drastically affects normal protein structure. These mutations abolish normal enzyme activity, leading to a severe phenotype of congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency. (J Clin Endocrinol Metab 94: 3481-3485, 2009)

Val247Leu polymorphism of beta(2) glycoprotein 1 gene may justify the genesis of anti beta(2)GP1 antibodies and Antiphospholipid Syndrome in Multibacillary Leprosy

BACKGROUND - Multibacillary (MB) leprosy may be manifested with antiphospholipid antibodies (aPL), among which anti-beta(2)GP1 (beta(2)-glycoprotein 1). High titers of aPL are associated with APS (Antiphospholipid Syndrome), characterized by thrombosis. The mutation Val247Leu in the domain V of beta(2)GP1 exposes hidden epitopes with consequent development of anti-beta(2)GP1 antibodies. OBJECTIVE: To evaluate the Val247Leu polymorphism of beta(2)GP1 gene and its correlation with anti-beta(2)GP1 antibodies in leprosy patients. METHODS: The Val247Leu polymorphism was performed by PCR-RFLP and anti-beta(2)GP1 antibodies were measured by ELISA. RESULTS: The genotypic Val/Val was more prevalent in the leprosy group, compared to controls. Regarding the 7 MB patients with APS, four presented heterozygosis and three, Val/Val homozygosis. Although higher titrations of anti-beta(2)GP1 IgM antibodies were seen in MB leprosy group with Val/Leu and Val/Val genotypes, there was no statistical difference when compared to Leu/Leu genotype. CONCLUSION: The prevalence of Val/Val homozygosis in leprosy group can partially justify the presence of anti-beta(2)GP1 IgM antibodies in MB leprosy. The description of heterozygosis and Val/Val homozygosis in 7 patients with MB leprosy and thrombosis corroborates the implication of anomalous phenotype expression of beta(2)GP1 and development of anti-beta(2)GP1 antibodies, with consequent thrombosis and APS.

Differential gene expression of peripheral blood mononuclear cells from rheumatoid arthritis patients may discriminate immunogenetic, pathogenic and treatment features

This study aimed to evaluate the association between the differential gene expression profiling of peripheral blood mononuclear cells of rheumatoid arthritis patients with their immunogenetic (human leucocyte antigen shared-epitope, HLA-SE), autoimmune response [anti-cyclic citrullinated peptide (CCP) antibodies], disease activity score (DAS-28) and treatment (disease-modifying antirheumatic drugs and tumour necrosis factor blocker) features. Total RNA samples were copied into Cy3-labelled complementary DNA probes, hybridized onto a glass slide microarray containing 4500 human IMAGE complementary DNA target sequences. The Cy3-monocolour microarray images from patients were quantified and normalized. Analysis of the data using the significance analysis of microarrays algorithm together with a Venn diagram allowed the identification of shared and of exclusively modulated genes, according to patient features. Thirteen genes were exclusively associated with the presence of HLA-SE alleles, whose major biological function was related to signal transduction, phosphorylation and apoptosis. Ninety-one genes were associated with disease activity, being involved in signal transduction, apoptosis, response to stress and DNA damage. One hundred and one genes were associated with the presence of anti-CCP antibodies, being involved in signal transduction, cell proliferation and apoptosis. Twenty-eight genes were associated with tumour necrosis factor blocker treatment, being involved in intracellular signalling cascade, phosphorylation and protein transport. Some of these genes had been previously associated with rheumatoid arthritis pathogenesis, whereas others were unveiled for future research.

DC-SIGN (CD209) gene promoter polymorphisms in a Brazilian population and their association with human T-cell lymphotropic virus type 1 infection

This study evaluated four polymorphisms located in the DC-SIGN (CD209) gene promoter region (positions -336, -332 -201 and -139) in DNA samples from four Brazilian ethnic groups (Caucasians, Afro-Brazilian, Asians and Amerindians) to establish the population distribution of these single-nucleotide polymorphisms (SNPs) and correlated DC-SIGN polymorphisms and infection in samples from human T-cell lymphotropic virus type 1 (HTLV-1)-infected individuals. To identify CD209 SNPs, 452 bp of the CD209 promoter region were sequenced and the genotype and allelic frequencies were evaluated. This is the first study to show genetic polymorphism in the CD209 gene in distinct Brazilian ethnic groups with the distribution of allelic and genotypic frequency. The results showed that -336A and -139A SNPs were quite common in Asians and that the -201T allele was not observed in Caucasians, Asians or Amerindians. No significant differences were observed between individuals with HTLV-1 disease and asymptomatic patients. However, the -336A variant was more frequent in HTLV-1 -infected patients [HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), 80%; healthy asymptomatic HTLV-1 carriers, 90 %] than in the control group (70 %) [P=0.0197, odds ratio (OR)=2.511, 95 % confidence interval (CI)=1.218-5.179). In addition, the -139A allele was found to be associated with protection against HTLV-1 infection (P=0.0037, OR=0.3758, 95% CI=0.1954-0.7229) when the HTLV-1 -infected patients as a whole were compared with the healthy-control group. These observations suggest that the -139A allele may be associated with HTLV-1 infection, although no significant association was observed among asymptomatic and HAM/TSP patients. In conclusion, the variation observed in SNPs -336 and -139 indicates that this lectin may be of crucial importance in the susceptibility/transmission of HTLV-1 infections.

Consequences of lifetime isolated growth hormone (GH) deficiency and effects of short-term GH treatment on bone in adults with a mutation in the GHRH-receptor gene

Growth hormone (GH) influences bone mass maintenance. However, the consequences of lifetime isolated GH deficiency (IGHD) on bone are not well established. We assessed the bone status and the effect of 6 months of GH replacement in GH-naive adults with IGHD due to a homozygous mutation of the GH-releasing hormone (GHRH)-receptor gene (GHRHR). We studied 20 individuals (10 men) with IGHD at baseline, after 6 months of depot GH treatment, and 6 and 12 months after discontinuation of GH. Quantitative ultrasound (QUS) of the heel was performed and serum osteocalcin (OC) and C-terminal cross-linking telopeptide of type I collagen (ICTP) were measured. QUS was also performed at baseline and 12 months later in a group of 20 normal control individuals (CO), who did not receive GH treatment. At baseline, the IGHD group had a lower T-score on QUS than CO (-1.15 +/- 0.9 vs. -0.07 +/- 0.9, P < 0.001). GH treatment improved this parameter, with improvement persisting for 12 months post-treatment (T-score for IGHD = -0.59 +/- 0.9, P < 0.05). GH also caused an increase in serum OC (baseline vs. pGH, P < 0.001) and ICTP (baseline vs. pGH, P < 0.01). The increase in OC was more marked during treatment and its reduction was slower after GH discontinuation than in ICTP. These data suggest that lifetime severe IGHD is associated with significant reduction in QUS parameters, which are partially reversed by short-term depot GH treatment. The treatment induces a biochemical pattern of bone anabolism that persists for at least 6 months after treatment discontinuation.

Association of Interferon-gamma gene polymorphism (+874 T/A) with systemic sclerosis

Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Cultural Consonance, a 5HT2A Receptor Polymorphism, and Depressive Symptoms: A Longitudinal Study of Gene x Culture Interaction in Urban Brazil

In this study in urban Brazil we examine, as a predictor of depressive symptoms, the interaction between a single nucleotide polymorphism in the 2A receptor in the serotonin system (-1438G/A) and cultural consonance in family life, a measure of the degree to which an individual perceives her family as corresponding to a widely shared cultural model of the prototypical family. A community sample of 144 adults was followed over a 2-year-period. Cultural consonance in family life was assessed by linking individuals` perceptions of their own families with a shared cultural model of the family derived from cultural consensus analysis. The -1438G/A polymorphism in the 2A serotonin receptor was genotyped using a standard protocol for DNA extracted from leukocytes. Covariates included age, sex, socioeconomic status, and stressful life events. Cultural consonance in family life was prospectively associated with depressive symptoms. In addition, the interaction between genotype and cultural consonance in family life was significant. For individuals with the A/A variant of the -1438G/A polymorphism of the 2A receptor gene, the effect of cultural consonance in family life on depressive symptoms over a 2-year-period was larger (beta = -0.533, P < 0.01) than those effects for individuals with either the G/A (beta = -0.280, P < 0.10) or G/G (beta = -0.272, P < 0.05) variants. These results are consistent with a process in which genotype moderates the effects of culturally meaningful social experience on depressive symptoms. Am. J. Hum. Biol. 21:91-97, 2009. (C) 2008 Wiley-Liss, Inc.

Shared and Unique Gene Expression in Systemic Lupus Erythematosus Depending on Disease Activity

Patients presenting with active Systemic lupus erythematosus (SLE) manifestations may exhibit distinct pathogenetic features in relation to inactive SLE. Also, cDNA microarrays may potentially discriminate the gene expression profile of a disease or disease variant. Therefore, we evaluated the expression profile of 4500 genes in peripheral blood lymphocytes (PBL) of SLE patients. We studied 11 patients with SLE (seven with active SLE and four with inactive SLE) and eight healthy controls. Total RNA was isolated from PBL, reverse transcribed into cDNA, and postlabeled with Cy3 fluorochrome. These probes were then hybridized to a glass slide cDNA microarray containing 4500 human IMAGE cDNA target sequences. An equimolar amount of total RNA from human cell lines served as reference. The microarray images were quantified, normalized, and analyzed using the R environment (ANOVA, significant analysis of microarrays, and cluster-tree view algorithms). Disease activity was assessed by the SLE disease activity index. Compared to the healthy controls, 104 genes in active SLE patients (80 repressed and 24 induced) and 52 genes in nonactive SLE patients (31 induced and 21 repressed) were differentially expressed. The modulation of 12 genes, either induced or repressed, was found in both disease variants; however, each disease variant had differential expression of different genes. Taken together, these results indicate that the two lupus variants studied have common and unique differentially expressed genes. Although the biological significance of the differentially expressed genes discussed above has not been completely understood, they may serve as a platform to further explore the molecular basis of immune deregulation in SLE.

Mannose binding lectin gene (MBL2) functional polymorphisms are associated with systemic lupus erythematosus in southern Brazilians

Susceptibility to systemic lupus erythematosus (SLE) has been associated with immunologic, environmental, and genetic factors. To uncover a possible association between MBL2 gene polymorphisms and SLE, we analyzed functional polymorphisms in the promoter and first exon of the MBL2 gene in 134 Brazilian SLE patients and 101 healthy controls. Genotype and allele frequencies of MBL2 A/O polymorphism were significantly different between patients and controls, and the 0 allele was associated with an increased risk of SLE. An association between low mannose binding lectin (MBL) producer combined genotypes and increased risk for SLE was also reported. Furthermore, when stratifying SLE patients according to clinical and laboratory data, an association between the A/O genotype and nephritic disorders and between the X/Y genotype and antiphospholipid syndrome was evident. Combined genotypes responsible for low MBL production were more frequently observed in SLE patients with nephritis. Our results indicate MBL2 polymorphisms as possible risk factors for SLE development and disease-related clinical manifestations. (C) 2011 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Involvement of the Helicobacter pylori plasticity region and cag pathogenicity island genes in the development of gastroduodenal diseases

Infection by Helicobacter pylori is associated with the development of several gastroduodenal diseases, including gastritis, peptic ulcer disease (gastric ulcers and duodenal ulcers), and gastric adenocarcinoma. Although a number of putative virulence factors have been reported for H. pylori, there are conflicting results regarding their association with specific H. pylori-related diseases. In this work, we investigated the presence of virB11 and cagT, located in the left half of the cag pathogenicity island (cagPAI), and the jhp917-jhp918 sequences, components of the dupA gene located in the plasticity zone of H. pylori, in Brazilian isolates of H. pylori. We also examined the association between these genes and H. pylori-related gastritis, peptic ulcer disease, and gastric and duodenal ulcers in an attempt to identify a gene marker for clinical outcomes related to infection by H. pylori. The cagT gene was associated with peptic ulcer disease and gastric ulcers, whereas the virB11 gene was detected in nearly all of the samples. The dupA gene was not associated with duodenal ulcers or any gastroduodenal disease here analyzed. These results suggest that cagT could be a useful prognostic marker for the development of peptic ulcer disease in the state of Sao Paulo, Brazil. They also indicate that cagT is associated with greater virulence and peptic ulceration, and that this gene is an essential component of the type IV secretion system of H. pylori.