Anopheles aquasalis Infected by Plasmodium vivax Displays Unique Gene Expression Profiles when Compared to Other Malaria Vectors and Plasmodia

Malaria affects 300 million people worldwide every year and is endemic in 22 countries in the Americas where transmission occurs mainly in the Amazon Region. Most malaria cases in the Americas are caused by Plasmodium vivax, a parasite that is almost impossible to cultivate in vitro, and Anopheles aquasalis is an important malaria vector. Understanding the interactions between this vector and its parasite will provide important information for development of disease control strategies. To this end, we performed mRNA subtraction experiments using A. aquasalis 2 and 24 hours after feeding on blood and blood from malaria patients infected with P. vivax to identify changes in the mosquito vector gene induction that could be important during the initial steps of infection. A total of 2,138 clones of differentially expressed genes were sequenced and 496 high quality unique sequences were obtained. Annotation revealed 36% of sequences unrelated to genes in any database, suggesting that they were specific to A. aquasalis. A high number of sequences (59%) with no matches in any databases were found 24 h after infection. Genes related to embryogenesis were down-regulated in insects infected by P. vivax. Only a handful of genes related to immune responses were detected in our subtraction experiment. This apparent weak immune response of A. aquasalis to P. vivax infection could be related to the susceptibility of this vector to this important human malaria parasite. Analysis of some genes by real time PCR corroborated and expanded the subtraction results. Taken together, these data provide important new information about this poorly studied American malaria vector by revealing differences between the responses of A. aquasalis to P. vivax infection, in relation to better studied mosquito-Plasmodium pairs. These differences may be important for the development of malaria transmission-blocking strategies in the Americas

The JAK-STAT Pathway Controls Plasmodium vivax Load in Early Stages of Anopheles aquasalis Infection

Malaria affects 300 million people worldwide every year and 450,000 in Brazil. In coastal areas of Brazil, the main malaria vector is Anopheles aquasalis, and Plasmodium vivax is responsible for the majority of malaria cases in the Americas. Insects possess a powerful immune system to combat infections. Three pathways control the insect immune response: Toll, IMD, and JAK-STAT. Here we analyze the immune role of the A. aquasalis JAK-STAT pathway after P. vivax infection. Three genes, the transcription factor Signal Transducers and Activators of Transcription (STAT), the regulatory Protein Inhibitors of Activated STAT (PIAS) and the Nitric Oxide Synthase enzyme (NOS) were characterized. Expression of STAT and PIAS was higher in males than females and in eggs and first instar larvae when compared to larvae and pupae. RNA levels for STAT and PIAS increased 24 and 36 hours (h) after P. vivax challenge. NOS transcription increased 36 h post infection (hpi) while this protein was already detected in some midgut epithelial cells 24 hpi. Imunocytochemistry experiments using specific antibodies showed that in non-infected insects STAT and PIAS were found mostly in the fat body, while in infected mosquitoes the proteins were found in other body tissues. The knockdown of STAT by RNAi increased the number of oocysts in the midgut of A. aquasalis. This is the first clear evidence for the involvement of a specific immune pathway in the interaction of the Brazilian malaria vector A. aquasalis with P. vivax, delineating a potential target for the future development of disease controlling strategies

Downregulation of PHEX in multibacillary leprosy patients: observational cross-sectional study

Submitted by sandra infurna ([email protected]) on 2016-03-17T16:41:44Z No. of bitstreams: 1 pedro_silva_etal_IOC_2015.pdf: 1297760 bytes, checksum: 4981ff61f37bf82b229de5fdfa9263c9 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-03-17T16:57:22Z (GMT) No. of bitstreams: 1 pedro_silva_etal_IOC_2015.pdf: 1297760 bytes, checksum: 4981ff61f37bf82b229de5fdfa9263c9 (MD5)Made available in DSpace on 2016-03-17T16:57:22Z (GMT). No. of bitstreams: 1 pedro_silva_etal_IOC_2015.pdf: 1297760 bytes, checksum: 4981ff61f37bf82b229de5fdfa9263c9 (MD5) Previous issue date: 2015Universidade do Estado do Rio de Janeiro (UERJ). Faculdade de Ciências Médicas. Departamento de Patologia e Laboratórios. Disciplina de Patologia Geral e Laboratório de Imunopatologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Hanseníase. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Parasitas e Vetores. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Hanseníase. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Hanseníase. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro (UERJ). Faculdade de Ciências Médicas. Departamento de Radiologia. Serviço de Medicina Nuclear. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Microbiologia Celular. Rio de Janeiro, RJ, BrasilUniversidade do Estado do Rio de Janeiro (UERJ). Faculdade de Ciências Médicas. Departamento de Radiologia. Serviço de Medicina Nuclear. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Hanseníase. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Microbiologia Celular. Rio de Janeiro, RJ, Brasil / Universidade do Estado do Rio de Janeiro (UERJ). Faculdade de Ciências Médicas. Departamento de Patologia e Laboratórios. Disciplina de Patologia Geral e Laboratório de Imunopatologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Hanseníase. Rio de Janeiro, RJ, Brasil / Universidade do Estado do Rio de Janeiro (UERJ). Faculdade de Ciências Médicas. Departamento de Patologia e Laboratórios. Disciplina de Patologia Geral e Laboratório de Imunopatologia. Rio de Janeiro, RJ, Brasil.Background: Peripheral nerve injury and bone lesions, well known leprosy complications, lead to deformities and incapacities. The phosphate-regulating gene with homologies to endopeptidase on the X chromosome (PHEX) encodes a homonymous protein (PHEX) implicated in bone metabolism. PHEX/PHEX alterations may result in bone and cartilage lesions. PHEX expression is downregulated by intracellular Mycobacterium leprae (M. leprae) in cultures of human Schwann cells and osteoblasts. M. leprae in vivo effect on PHEX/PHEX is not known. Methods: Cross-sectional observational study of 36 leprosy patients (22 lepromatous and 14 borderline-tuberculoid) and 20 healthy volunteers (HV). The following tests were performed: PHEX flow cytometric analysis on blood mononuclear cells, cytokine production in culture supernatant, 25-hydroxyvitamin D (OHvitD) serum levels and 99mTc-MDP three-phase bone scintigraphy, radiography of upper and lower extremities and blood and urine biochemistry. Results: Significantly lower PHEX expression levels were observed in lepromatous patients than in the other groups (χ2 = 16.554, p < 0.001 for lymphocytes and χ2 = 13.933, p = 0.001 for monocytes). Low levels of 25-(OHvitD) were observed in HV (median = 23.0 ng/mL) and BT patients (median = 27.5 ng/mL) and normal serum levels were found in LL patients (median = 38.6 ng/mL). Inflammatory cytokines, such as TNF, a PHEX transcription repressor, were lower after stimulation with M. leprae in peripheral blood mononuclear cells from lepromatous in comparison to BT patients and HV (χ2 = 10.820, p < 0.001). Conclusion: Downregulation of PHEX may constitute an important early component of bone loss and joint damage in leprosy. The present results suggest a direct effect produced by M. leprae on the osteoarticular system that may use this mechanism

Anti-parasitic Guanidine and Pyrimidine Alkaloids from the Marine Sponge <i>Monanchora arbuscula</i>

HPLC-UV-ELSD-MS-guided fractionation of the anti-parasitic extract obtained from the marine sponge <i>Monanchora arbuscula</i>, collected off the southeastern coast of Brazil, led to the isolation of a series of guanidine and pyrimidine alkaloids. The pyrimidines monalidine A (<b>1</b>) and arbusculidine A (<b>7</b>), as well as the guanidine alkaloids batzellamide A (<b>8</b>) and hemibatzelladines <b>9</b>–<b>11</b>, represent new minor constituents that were identified by analysis of spectroscopic data. The total synthesis of monalidine A confirmed its structure. Arbusculidine A (<b>7</b>), related to the ptilocaulin/mirabilin/netamine family of tricyclic guanidine alkaloids, is the first in this family to possess a benzene ring. Batzellamide A (<b>8</b>) and hemibatzelladines <b>9</b>–<b>11</b> represent new carbon skeletons that are related to the batzelladines. Evaluation of the anti-parasitic activity of the major known metabolites, batzelladines D (<b>12</b>), F (<b>13</b>), L (<b>14</b>), and nor-L (<b>15</b>), as well as of synthetic monalidine A (<b>1</b>), against <i>Trypanosoma cruzi</i> and <i>Leishmania infantum</i> is also reported, along with a detailed investigation of parasite cell-death pathways promoted by batzelladine L (<b>14</b>) and norbatzelladine L (<b>15</b>)