Humoral responses in Rhodnius prolixus: bacterial feeding induces differential patterns of antibacterial activity and enhances mRNA levels of antimicrobial peptides in the midgut

Made available in DSpace on 2015-05-04T17:07:31Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) cecilia_vieiraetal_IOC-2104.pdf: 1062015 bytes, checksum: e8dde228f0bdd6c4004641893450e0cb (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense (UFF).Instituto de Biologia. Departamento de Biologia Geral. Laboratório de Biologia de Insetos. Niterói, RJ, Brasil.Universidade Federal Fluminense (UFF).Instituto de Biologia. Departamento de Biologia Geral. Laboratório de Biologia de Insetos. Niterói, RJ, Brasil / Swansea University. College of Science. Swansea, Wales, UK.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM). Departamento de Entomologia Molecular, Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM). Departamento de Entomologia Molecular, Rio de Janeiro, RJ, Brasil.Background The triatomine, Rhodnius prolixus, is a major vector of Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. It has a strictly blood-sucking habit in all life stages, ingesting large amounts of blood from vertebrate hosts from which it can acquire pathogenic microorganisms. In this context, the production of antimicrobial peptides (AMPs) in the midgut of the insect is vital to control possible infection, and to maintain the microbiota already present in the digestive tract. Methods In the present work, we studied the antimicrobial activity of the Rhodnius prolixus midgut in vitro against the Gram-negative and Gram-positive bacteria Escherichia coli and Staphylococcus aureus, respectively. We also analysed the abundance of mRNAs encoding for defensins, prolixicin and lysozymes in the midgut of insects orally infected by these bacteria at 1 and 7 days after feeding. Results Our results showed that the anterior midgut contents contain a higher inducible antibacterial activity than those of the posterior midgut. We observed that the main AMP encoding mRNAs in the anterior midgut, 7 days after a blood meal, were for lysozyme A, B, defensin C and prolixicin while in the posterior midgut lysozyme B and prolixicin transcripts predominated. Conclusion Our findings suggest that R. prolixus modulates AMP gene expression upon ingestion of bacteria with patterns that are distinct and dependent upon the species of bacteria responsible for infection

BLOOD and PLACENTAL OXIDATIVE STRESS ASSESSMENT IN RATS WITH MILD DIABETES

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Genotoxicity Evaluation in Severe or Mild Diabetic Pregnancy in Laboratory Animals

This study aimed to evaluate the genotoxicity (DNA damage levels) in lymphocyte samples from pregnant Wistar rats with severe or mild diabetes and in whole blood samples from their newborns. Wistar female rats (1 and 90 days of age) and male rats (approximately 90 days of age) were used. The experiment consisted of 2 experimental groups (n = 8 animals/group): 1) rats with severe diabetes, 2) rats with mild diabetes. For mild diabetes induction, the rats received streptozotocin (STZ) subcutaneously (100 mg/kg body weight) at day of birth, and those showing glycemia from 120 to 300 mg/dL in their adult life were included. For induction of severe diabetes, adult rats received 40 mg/kg STZ (intravenous route), and those showing glycemia >300 mg/dL were included. At day 21 of pregnancy, the, rats were anesthetized and euthanized for removal of maternal and fetal blood samples for determination of the oxidative DNA damage by applying Endo III and Fpg using the comet assay. Thus, the rats with mild diabetes and their offspring showed higher Fpg-sensitive sites, reflecting the damage resulting from hyperglycemia. The rats with severe diabetes and their offspring showed higher oxidative DNA damage detected by Fpg and Endo III-sensitive sites, showing general repercussions related to diabetes. The enzymatic treatment for DNA damage evidenced that the maternal repercussions of diabetes are associated with oxidative DNA damage of their newborn, which was not reflected using only the analysis of DNA damage free of the enzymes.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. on day 21 of pregnancy, the adult rats (weighing approximately 250 ± 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 ± 0.2) and SOD (G3 = 223.0 ± 84.7; G4 = 146.1 ± 40.8), and decreased fetal CAT activity (G3 = 22.4 ± 10.6; G4 = 34.4 ± 14.1) and GSH-t (G3 = G4 = 0.3 ± 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 ± 0.2 and SOD = 274.1 ± 80.3; fetal CAT = 92.6 ± 82.7 and GSH-t = 0.6 ± 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days)

Rhodnius prolixus interaction with Trypanosoma rangeli: modulation of the immune system and microbiota population

Submitted by sandra infurna ([email protected]) on 2016-05-11T11:06:19Z No. of bitstreams: 1 cecilia_vieira_etal_IOC_2015.pdf: 1447403 bytes, checksum: 9b50113b9471461d6d9b11f81121be77 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-05-11T13:05:36Z (GMT) No. of bitstreams: 1 cecilia_vieira_etal_IOC_2015.pdf: 1447403 bytes, checksum: 9b50113b9471461d6d9b11f81121be77 (MD5)Made available in DSpace on 2016-05-11T13:05:36Z (GMT). No. of bitstreams: 1 cecilia_vieira_etal_IOC_2015.pdf: 1447403 bytes, checksum: 9b50113b9471461d6d9b11f81121be77 (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Universidade Federal Rural do Rio de Janeiro (UFRRJ). Instituto de Florestas. Departamento de Ciências Ambientais. Seropédica, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM). Departamento de Entomologia Molecular. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM). Departamento de Entomologia Molecular. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Entomologia Molecular (INCT-EM). Departamento de Entomologia Molecular. Rio de Janeiro, RJ. Brasil.Background: Trypanosoma rangeli is a protozoan that infects a variety of mammalian hosts, including humans. Its main insect vector is Rhodnius prolixus and is found in several Latin American countries. The R. prolixus vector competence depends on the T. rangeli strain and the molecular interactions, as well as the insect’s immune responses in the gut and haemocoel. This work focuses on the modulation of the humoral immune responses of the midgut of R. prolixus infected with T. rangeli Macias strain, considering the influence of the parasite on the intestinal microbiota. Methods: The population density of T. rangeli Macias strain was analysed in different R. prolixus midgut compartments in long and short-term experiments. Cultivable and non-cultivable midgut bacteria were investigated by colony forming unit (CFU) assays and by 454 pyrosequencing of the 16S rRNA gene, respectively. The modulation of R. prolixus immune responses was studied by analysis of the antimicrobial activity in vitro against different bacteria using turbidimetric tests, the abundance of mRNAs encoding antimicrobial peptides (AMPs) defensin (DefA, DefB, DefC), prolixicin (Prol) and lysozymes (LysA, LysB) by RT-PCR and analysis of the phenoloxidase (PO) activity. Results: Our results showed that T. rangeli successfully colonized R. prolixus midgut altering the microbiota population and the immune responses as follows: 1 - reduced cultivable midgut bacteria; 2 - decreased the number of sequences of the Enterococcaceae but increased those of the Burkholderiaceae family; the families Nocardiaceae, Enterobacteriaceae and Mycobacteriaceae encountered in control and infected insects remained the same; 3 - enhanced midgut antibacterial activities against Serratia marcescens and Staphylococcus aureus; 4 - downregulated LysB and Prol mRNA levels; altered DefB, DefC and LysA depending on the infection (short and longterm); 5 - decreased PO activity. Conclusion: Our findings suggest that T. rangeli Macias strain modulates R. prolixus immune system and modifies the natural microbiota composition

Effects of Annona squamosa extract on early pregnancy in rats

Annona squamosa Linn., family Annonaceae, is said to show varied medicinal effects, including insecticide, antiovulatory and abortifacient. The purpose of present study was to investigate if A. squamosa seed aqueous extract, in doses higher than that popularly used to provoke abortion, interferes with reproductive performance, and to correlate the ingestion of this extract with possible alterations in rat embryonic implantation. Doses of 300 mg/kg (Treated Group I, n = 17) and 600 mg/kg (Treated Group II, n = 12) body wt. were administered by gavage, during days 1 to 5 of pregnancy (preimplantation period). The control group (n = 13) received water in the same manner, during the same period for comparison with experimental groups. The animals were euthanized on day 10 of pregnancy. Treatment of dams during the preimplantation period showed no signs of toxicity, and no alteration in the corpora lutea, implantations and embryo in terms of development numbers. The percentage of preimplantation and postimplantation losses in treated groups I and II did not differ from those of control. Treatment with aqueous extract of A. squamosa seeds caused no morphological change in the endometrium. The absence of morphological alterations in uterine epithelial cells in treated groups I and II permitted a viable embryonic implantation, as verified by the number of embryos in development at day 10 of pregnancy. Thus, A. squamosa seed aqueous extract did not interfere with the reproductive performance of pregnant rats