Drosophila Myc interacts with host cell factor (dHCF) to activate transcription and control growth.

The Myc proto-oncoproteins are transcription factors that recognize numerous target genes through hexameric DNA sequences called E-boxes. The mechanism by which they then activate the expression of these targets is still under debate. Here, we use an RNAi screen in Drosophila S2 cells to identify Drosophila host cell factor (dHCF) as a novel co-factor for Myc that is functionally required for the activation of a Myc-dependent reporter construct. dHCF is also essential for the full activation of endogenous Myc target genes in S2 cells, and for the ability of Myc to promote growth in vivo. Myc and dHCF physically interact, and they colocalize on common target genes. Furthermore, down-regulation of dHCF-associated histone acetyltransferase and histone methyltransferase complexes in vivo interferes with the Myc biological activities. We therefore propose that dHCF recruits such chromatin-modifying complexes and thereby contributes to the expression of Myc targets and hence to the execution of Myc biological activities.

CTCF-T, a paralogue of CTCF, directs sequence specific DNA methylation of the imprinting control region of Igf2/H19

SUMMARY Genomic imprinting is an epigenetic mechanism of transcriptional regulation that ensures restriction of expression of a subset of mammalian genes to a single parental allele. The best studied example of imprinted gene regulation is the Igf2/H19 locus, which is also the most commonly altered by loss of imprinting (LOT) in cancer. LOT is associated with numerous hereditary diseases and several childhood, and adult cancers. Differential expression of reciprocal H19 and 1gf2 alleles in somatic cells depends on the methylation status of the imprinting control region (ICR) which regulates binding of CTCF, an ubiquitously expressed 11-zinc finger protein that binds specifically to non-methylated maternal ICR and thereby attenuates expression of Igf2, while it does not bind to methylated paternal ICR, which enables Igf2 expression. Initial ICR methylation occurs during gametogenesis by an as yet unknown mechanism. The accepted hypothesis is that the event of differential maternal and paternal DNA methylation depends on germ-line specific proteins. Our Laboratory identified a novel 11-zinc-finger protein CTCF-T (also known as CTCFL and BORIS) that is uniquely expressed in the male germ-line and is highly homologous within its zinc-finger region with CTCF. The amino-acid sequences flanking the zinc-finger regions of CTCF and CTCF-T have widely diverged, suggesting that though they could bind to the same DNA targets (ICRs) they are likely to have different functions. Interestingly, expression of CTCF-T and CTCF is mutually exclusive; CTCF-T-positive (CTCF-negative) cells occur in the stage of spermatogenesis that coincides with epigenetic reprogramming, including de novo DNA methylation. In our study we demonstrate the role that CTCF-T plays in genomic imprinting. Here we show that CTCF-T binds in vivo to the ICRs of Igf2/H19 and Dlk/Gt12 imprinted genes. In addition, we identified two novel proteins interacting with CTCF-T: a protein arginine methyltransferase PRMT7 and an arginine-rich histone H2A variant that we named trH2A. These interactions were confirmed and show that the two proteins interact with the amino-teiminal region of CTCF-T. Additionally, we show interaction of the amino- terminal region of CTCF-T with histones H1, H2A and H3. These results suggest that CTCF-T is a sequence-specific DNA (ICR) binding protein that associates with histones and recruits PRMT7. Interestingly, PRMT7 has a histone-methyltransferase activity. It has been shown that histone methylation can mark chromatin regions thereby directing DNA-methylation; thus, our hypothesis is that the CTCF-T protein-scaffold directs PRMT7 to methylate histone(s) assembled on ICRs, which marks chromatin for the recruitment of the de novo DNA methyltransferases to methylate DNA. To test this hypothesis, we developed an in vivo DNA-methylation assay using Xenopus laevis' oocytes, where H19 ICR and different expression cDNAs, including CTCF-T, PRMT7 and the de novo DNA methyltransferases (Dnmt3a, Dnmt3b and Dnmt3L) are microinjected into the nucleus. The methylation status of CpGs within the H19 ICR was analysed 48 or 72 hours after injection. Here we demonstrate that CpGs in the ICR are methylated in the presence of both CTCF-T and PRMT7, while control oocytes injected only with ICR did not show any methylation. Additionally, we showed for the first time that Dnmt3L is crucial for the establishment of the imprinting marks on H19 ICR. Moreover, we confirmed that Dnmt3a and Dnmt3b activities are complementary. Our data indicate that all three Dnmt3s are important for efficient de novo DNA methylation. In conclusion, we propose a mechanism for the establishment of de novo imprinting marks during spermatogenesis: the CTCF-T/PRMT7 protein complex directs histone methylation leading to sequence-specific de novo DNA methylation of H19 ICR. RESUME L'empreinte génomique parentale est un mécanisme épigénétique de régulation transcriptionelle qui se traduit par une expression différentielle des deux allèles de certains gènes, en fonction de leur origine parentale. L'exemple le mieux caractérisé de gènes soumis à l'empreinte génomique parentale est le locus Igf2/H19, qui est aussi le plus fréquemment altéré par relaxation d'empreinte (en anglais: loss of imprinting, LOI) dans les cancers. Cette relaxation d'empreinte est aussi associée à de nombreuses maladies héréditaires, ainsi qu'à de nombreux cancers chez l'enfant et l'adulte. Dans les cellules somatiques, les différences d'expression des allèles réciproques H19 et Ig12 est sous le contrôle d'une région ICR (Imprinting Control Region). La méthylation de cette région ICR régule l'ancrage de la protéine à douze doigts de zinc CTCF, qui se lie spécifiquement à l'ICR maternel non-méthylé, atténuant ainsi l'expression de Igf2, alors qu'elle ne s'ancre pas à l'ICR paternel méthyle. Le mécanisme qui accompagne la méthylation initiale de la région ICR durant la gamétogenèse n'a toujours pas été élucidé. L'hypothèse actuelle propose que la différence de méthylation entre l'ADN maternel et paternel résulte de l'expression de protéines propres aux zones germinales. Notre laboratoire a récemment identifié une nouvelle protéine à douze doigts de zinc, CTCF-T (aussi dénommée CTCFL et BORRIS), qui est exprimée uniquement dans les cellules germinales mâles, dont la partie à douze doigts de zinc est fortement homologue à la protéine CTCF. La séquence d'acides aminés de part et d'autre de cette région est quant à elle très divergente, ce qui implique que CTCF-T se lie sans doute au même ADN cible que CTCF, mais possède des fonctions différentes. De plus, l'expression de CTCF-T et de CTCF s'oppose mutuellement; l'expression de la protéine CTCF-T (cellules CTCF-T positives, CTCF negatives) qui a lieu pendant la spermatogenèse coïncide avec la reprogrammation épigénétique, notamment la méthylation de novo de l'ADN. La présente étude démontre le rôle essentiel joué par la protéine CTCF-T dans l'acquisition de l'empreinte génomique parentale. Nous montrons ici que CTCF-T s'associe in vivo avec les régions ICR des loci Igf2/H19 et Dlk/Gt12. Nous avons également identifié deux nouvelles protéines qui interagissent avec CTCF-T : une protéine arginine méthyl transférase PRMT7, et un variant de l'histone H2A, riche en arginine, que nous avons dénommé trH2A. Ces interactions ont été analysées plus en détail, et confinnent que ces deux protéines s'associent avec la région N-terminale de CTCF-T. Aussi, nous présentons une interaction de la région N-terminale de CTCF-T avec les histones H1, H2, et H3. Ces résultats suggèrent que CTCF-T est une protéine qui se lie spécifiquement aux régions ICR, qui s'associe avec différents histones et qui recrute PRMT7. PRMT7 possède une activité méthyl-tansférase envers les histones. Il a été montré que la méthylation des histones marque certains endroits de la chromatine, dirigeant ainsi la méthylation de l'ADN. Notre hypothèse est donc la suivante : la protéine CTCF-T sert de base qui dirige la méthylation des histones par PRMT7 dans les régions ICR, ce qui contribue à marquer la chromatine pour le recrutement de nouvelles méthyl transférases pour méthyler l'ADN. Afin de valider cette hypothèse, nous avons développé un système de méthylation de l'ADN in vivo, dans des oeufs de Xenopus laevis, dans le noyau desquels nous avons mico-injecté la région ICR du locus H19, ainsi que différents vecteurs d'expression pour CTCF-T, PRMT7, et les de novo méthyl transférases (Dnmt3a, Dnmt3b et Dnmt3L). Les CpGs méthyles de la région ICR du locus H19 ont été analysé 48 et 72 heures après l'injection. Cette technique nous a permis de démontrer que les CpGs de la région ICR sont méthyles en présence de CTCF-T et de PRMT7, tandis que les contrôles injectés seulement avec la région ICR ne présentent aucun signe de méthylation. De plus, nous démontrons pour la première fois que la protéine méthyl transférase Dnmt3L est déterminant pour l'établissement de l'empreinte génomique parentale au niveau de la région ICR du locus H19. Aussi, nous confirmons que les activités méthyl transférases de Dnmt3a et Dnmt3b sont complémentaires. Nos données indiquent que les trois protéines Dnmt3 sont impliquées dans la méthylation de l'ADN. En conclusion, nous proposons un mécanisme responsable de la mise en place de nouvelles empreintes génomiques pendant la spermatogenèse : le complexe protéique CTCF-T/PRMT7 dirige la méthylation des histones aboutissant à la méthylation de novo de l'ADN au locus H19.

Transmission factors in malaria epidemiology and control in Africa

Genetic and environmental components of factors contributing in malaria transmission are reviewed. Particular attention is given to density dependent regulation of vector populations in relation to the survival rate anophelines. The expectation of vector activities are different according to the epidemiological characteristics of malaria, mainly its stability. In areas with perennial and high transmission (stable malaria) vector control could reduce malaria related morbidity and mortality, whithout any effect on the endemicity. However this need further investigations. In areas where the transmission period is very short (unstable malaria), vector control will have an important impact on the disease and the endemicity. Control projects using indoor spraying with insecticide and impregnated bed nets are discussed.

TIE-2 and VEGFR Kinase Activities Drive Immunosuppressive Function of TIE-2-Expressing Monocytes in Human Breast Tumors.

PURPOSE: Tumor-associated TIE-2-expressing monocytes (TEM) are highly proangiogenic cells critical for tumor vascularization. We previously showed that, in human breast cancer, TIE-2 and VEGFR pathways control proangiogenic activity of TEMs. Here, we examine the contribution of these pathways to immunosuppressive activity of TEMs. EXPERIMENTAL DESIGN: We investigated the changes in immunosuppressive activity of TEMs and gene expression in response to specific kinase inhibitors of TIE-2 and VEGFR. The ability of tumor TEMs to suppress tumor-specific T-cell response mediated by tumor dendritic cells (DC) was measured in vitro. Characterization of TEM and DC phenotype in addition to their interaction with T cells was done using confocal microscopic images analysis of breast carcinomas. RESULTS: TEMs from breast tumors are able to suppress tumor-specific immune responses. Importantly, proangiogenic and suppressive functions of TEMs are similarly driven by TIE-2 and VEGFR kinase activity. Furthermore, we show that tumor TEMs can function as antigen-presenting cells and elicit a weak proliferation of T cells. Blocking TIE-2 and VEGFR kinase activity induced TEMs to change their phenotype into cells with features of myeloid dendritic cells. We show that immunosuppressive activity of TEMs is associated with high CD86 surface expression and extensive engagement of T regulatory cells in breast tumors. TIE-2 and VEGFR kinase activity was also necessary to maintain high CD86 surface expression levels and to convert T cells into regulatory cells. CONCLUSIONS: These results suggest that TEMs are plastic cells that can be reverted from suppressive, proangiogenic cells into cells that are able to mediate an antitumoral immune response. Clin Cancer Res; 19(13); 3439-49. ©2013 AACR.

The WHO Collaborating Centre for Research and Control of Schistosomiasis at Niamey, Niger

The Centre de Recherche sur les Méningites et les Schistosomes (CERMES) is a research institute depending on the Organisation de Coordination et de Coopération pour la lutte contre les Grandes Endémies - a West African Organization for Public Health - devoted to the studies on schistosomiasis and meningitis. The staff includes 32 persons with 11 scientists and one financial officer. The activities of the CERMES involving schistosomiasis concern three research units: (a) ecology of human and animal schistosomiasis transmission; the CERMES defined the different patterns of schistosomiasis transmission in Niger (involving African dry savana); in this field, we have shown, (i) the existence of important variability in conditions of transmission of S. haematobium and, (ii) natural hybridization between parasitic species of the ruminants (S. bovis and S. curassoni) and genetic interaction between human and animal parasites; (b) definition of morbidity indicators usable for rapid assessment methods, for appraisal of the severity of the disease and for the evaluation of the efficiency of control methods; we have established the correlation between ultrasonographic data and some cheap and simple field indicators; (c) immune response and protective immunity induced by recombinant glutathion S-transferase (Sm28, Sb28 and Sh28) in homologous and heterologous animal models including goats, sheep and non human primates (Erythrocebus patas). In Niger, we participate in all control programs against schistosomiasis to define control strategies, to supervise operations and to participate in their evaluation with external experts. International collaborations constitute a frame including four laboratories in Africa and six laboratories in developed countries (Europe and USA)

Factors associated with clinical leptospirosis: a population-based case-control study in the Seychelles (Indian Ocean).

BACKGROUND: In Western countries, leptospirosis is uncommon and mainly occurs in farmers and individuals indulging in water-related activities. In tropical countries, leptospirosis can be up to 1000 times more frequent and risk factors for this often severe disease may differ. METHODS: We conducted a one-year population-based matched case-control study to investigate the frequency and associated factors of leptospirosis in the entire population of Seychelles. RESULTS: A total of 75 patients had definite acute leptospirosis based on microagglutination test (MAT) and polymerase chain reaction (PCR) assay (incidence: 101 per 100,000 per year; 95% confidence interval [CI]: 79-126). Among the controls, MAT was positive in 37% (past infection) and PCR assay in 9% (subclinical infection) of men aged 25-64 with manual occupation. Comparing cases and controls with negative MAT and PCR, leptospirosis was associated positively with walking barefoot around the home, washing in streams, gardening, activities in forests, alcohol consumption, rainfall, wet soil around the home, refuse around the home, rats visible around the home during day time, cats in the home, skin wounds and inversely with indoor occupation. The considered factors accounted for as much as 57% of the variance in predicting the disease. CONCLUSION: These data indicate a high incidence of leptospirosis in Seychelles. This suggests that leptospires are likely to be ubiquitous and that effective leptospirosis control in tropical countries needs a multifactorial approach including major behaviour change by large segments of the general public.

Adenosine Deaminase Activities in Sera, Lymphocytes and Granulocytes in Patients with Cutaneous Leishmaniasis

Adenosine deaminase (ADA) activities in sera, lymphocytes and granulocytes in patients with cutaneous leishmaniasis were investigated and compared with control groups. Fifty patients and 50 healthy individuals were studied. The clinical diagnosis was parasitologically confirmed by culture and Giemsa stain. ADA activities were measured by colorimetric method. Serum ADA activities 37.80 ± 11.90, 18.28 ± 6.08 IU/L (p<0.0001), lymphocyte specific ADA activities 14.90 ± 7.42, 8.38 ± 7.42 U/mg protein (p = 0.04), granulocyte specific ADA activities 1.15 ± 0.73 , 1.09 ± 0.67 U/mg protein ( p>0.05) were found in patients and control groups, respectively. ADA activity increases in some infectious diseases were cell mediated immune mechanisms are dominant. In cutaneous leishmaniasis, lymphokine-mediated macrophage activity is the main effector mechanism. Increase in serum and lymphocyte ADA activities in patients with cutaneous leishmaniasis may be dependent on and reflects the increase in phagocytic activity of macrophages and maturation of T-lymphocytes.

Adenosine Deaminase and Guanosine Deaminase Activities in Sera of Patients with Viral Hepatitis

In order to investigate purin and primidin metabolism pathways in hepatitis, adenosine deaminase (ADA) and guanosine deaminase (GDA) activities in sera of patients with different types and manifestations of viral hepatitis disease (A, B, C, D, E, chronic, acute) were investigated and compared with the control group of healthy individuals. Hepatitis cases were classified with respect to their serological findings and clinics. When compared all the hepatitis cases with the controls, levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase enzymes, as well as ADA and GDA, were significantly higher than the control group (p<0.01). Levels of ADA and GDA in hepatitis cases were determined as 26.07±11.98 IU/l and 2.37±1.91 IU/l, respectively. When compared their ADA and GDA levels amongst the classified hepatitis groups, there was no difference in ADA levels amongst cases (p>0.05). However, GDA levels in hepatitis A group were closed to the controls. Increase in serum ADA activities in hepatitis forms may be dependent on and reflect the increase in phagocytic activity of macrophages and maturation of T-lymphocytes, and may be valuable in monitoring in viral hepatitis cases.

Biology, diversity and strategies for the monitoring and control of triatomines - Chagas disease vectors

Despite the relevant achievements in the control of the main Chagas disease vectors Triatoma infestans and Rhodnius prolixus, several factors still promote the risk of infection. The disease is a real threat to the poor rural regions of several countries in Latin America. The current situation in Brazil requires renewed attention due to its high diversity of triatomine species and to the rapid and drastic environmental changes that are occurring. Using the biology, behaviour and diversity of triatomines as a basis for new strategies for monitoring and controlling the vectorial transmission are discussed here. The importance of ongoing long-term monitoring activities for house infestations by T. infestans, Triatoma brasiliensis, Panstrongylus megistus, Triatoma rubrovaria and R. prolixus is also stressed, as well as understanding the invasion by sylvatic species. Moreover, the insecticide resistance is analysed. Strong efforts to sustain and improve surveillance procedures are crucial, especially when the vectorial transmission is considered interrupted in many endemic areas.

Epidemiology and control of malaria in Colombia

Malaria is currently one of the most serious public health problems in Colombia with an endemic/epidemic transmission pattern that has maintained endemic levels and an average of 105,000 annual clinical cases being reported over the last five years. Plasmodium vivax accounts for approximately 70% of reported cases with the remainder attributed almost exclusively to Plasmodium falciparum. A limited number of severe and complicated cases have resulted in mortality, which is a downward trend that has been maintained over the last few years. More than 90% of the malaria cases in Colombia are confined to 70 municipalities (about 7% of the total municipalities of Colombia), with high predominance (85%) in rural areas. The purpose of this paper is to review the progress of malaria-eradication activities and control measures over the past century within the eco-epidemiologic context of malaria transmission together with official consolidated morbidity and mortality reports. This review may contribute to the formulation of new antimalarial strategies and policies intended to achieve malaria elimination/eradication in Colombia and in the region.

Deficits in executive and memory processes in delusional disorder: a case-control study

OBJECTIVE Delusional disorder has been traditionally considered a psychotic syndrome that does not evolve to cognitive deterioration. However, to date, very little empirical research has been done to explore cognitive executive components and memory processes in Delusional Disorder patients. This study will investigate whether patients with delusional disorder are intact in both executive function components (such as flexibility, impulsivity and updating components) and memory processes (such as immediate, short term and long term recall, learning and recognition). METHODS A large sample of patients with delusional disorder (n = 86) and a group of healthy controls (n = 343) were compared with regard to their performance in a broad battery of neuropsychological tests including Trail Making Test, Wisconsin Card Sorting Test, Colour-Word Stroop Test, and Complutense Verbal Learning Test (TAVEC). RESULTS When compared to controls, cases of delusional disorder showed a significantly poorer performance in most cognitive tests. Thus, we demonstrate deficits in flexibility, impulsivity and updating components of executive functions as well as in memory processes. These findings held significant after taking into account sex, age, educational level and premorbid IQ. CONCLUSIONS Our results do not support the traditional notion of patients with delusional disorder being cognitively intact.

Control programme for cystic echinococcosis in Uruguay

Cystic echinococcosis is a highly endemic parasitic zoonosis that is present in the Southern Cone countries of America. For several decades, various prevention and control programmes have been implemented in different countries and regions, with varying results. In Uruguay, a new control programme was implemented in 2006 that employed new strategies for canine diagnosis and treatment, dog population control, diagnosis in humans, epidemiological surveillance, and health education, including community participation. The control programme in Uruguay addresses the control and surveillance of the disease from a holistic perspective based on Primary Health Care, which has strengthened the community’s participation in developing and coordinating activities in an interdisciplinary manner. Similarly, the control programme that is currently implemented is based on a risk-focused approach. The surveillance and control measures were focused on small villages and extremely poor urban areas. In this study, the strategies used and the results obtained from 2008-2013 are analysed and discussed.

Health for life : annual report of activities for the period January-December 2013

In Seychelles, cardiovascular diseases (CVD), notably stroke, ischemic heart disease and hypertensive heart disease has become the largest contributor of deaths (40%) in the entire population. CVD also results in a large burden of disability and also has subsequent social and economic impact. The Unit for Prevention and Control of Cardiovascular Diseases (UPCCD) provides leadership, expertise and capacity at national level for the surveillance, prevention and control of cardiovascular diseases through education, programs and input into policy.

Ambulatory monitoring of physical activities in patients with Parkinson's disease.

A new ambulatory method of monitoring physical activities in Parkinson's disease (PD) patients is proposed based on a portable data-logger with three body-fixed inertial sensors. A group of ten PD patients treated with subthalamic nucleus deep brain stimulation (STN-DBS) and ten normal control subjects followed a protocol of typical daily activities and the whole period of the measurement was recorded by video. Walking periods were recognized using two sensors on shanks and lying periods were detected using a sensor on trunk. By calculating kinematics features of the trunk movements during the transitions between sitting and standing postures and using a statistical classifier, sit-to-stand (SiSt) and stand-to-sit (StSi) transitions were detected and separated from other body movements. Finally, a fuzzy classifier used this information to detect periods of sitting and standing. The proposed method showed a high sensitivity and specificity for the detection of basic body postures allocations: sitting, standing, lying, and walking periods, both in PD patients and healthy subjects. We found significant differences in parameters related to SiSt and StSi transitions between PD patients and controls and also between PD patients with and without STN-DBS turned on. We concluded that our method provides a simple, accurate, and effective means to objectively quantify physical activities in both normal and PD patients and may prove useful to assess the level of motor functions in the latter.

The control of microtubule stability in vitro and in transfected cells by MAP1B and SCG10.

In neurons, the regulation of microtubules plays an important role for neurite outgrowth, axonal elongation, and growth cone steering. SCG10 family proteins are the only known neuronal proteins that have a strong destabilizing effect, are highly enriched in growth cones and are thought to play an important role during axonal elongation. MAP1B, a microtubule-stabilizing protein, is found in growth cones as well, therefore it was important to test their effect on microtubules in the presence of both proteins. We used recombinant proteins in microtubule assembly assays and in transfected COS-7 cells to analyze their combined effects in vitro and in living cells, respectively. Individually, both proteins showed their expected activities in microtubule stabilization and destruction respectively. In MAP1B/SCG10 double-transfected cells, MAP1B could not protect microtubules from SCG10-induced disassembly in most cells, in particular not in cells that contained high levels of SCG10. This suggests that SCG10 is more potent to destabilize microtubules than MAP1B to rescue them. In microtubule assembly assays, MAP1B promoted microtubule formation at a ratio of 1 MAP1B per 70 tubulin dimers while a ratio of 1 SCG10 per two tubulin dimers was needed to destroy microtubules. In addition to its known binding to tubulin dimers, SCG10 binds also to purified microtubules in growth cones of dorsal root ganglion neurons in culture. In conclusion, neuronal microtubules are regulated by antagonistic effects of MAP1B and SCG10 and a fine tuning of the balance of these proteins may be critical for the regulation of microtubule dynamics in growth cones.