Metarhizium anisopliae E6 secretome reveals molecular players in host specificity and toxicity linked to cattle tick infection.

Although Metarhizium anisopliae is one of the most studied fungal biocontrol agents, its infection mechanism is far from being completely understood. Using multidimensional protein identification technology (MudPIT), we evaluated the differential secretome of M. anisopliae E6 induced by the host Rhipicephalus microplus cuticle. The proteomic result showed changes in the expression of 194 proteins after exposure to host cuticle, such as proteins involved in adhesion, penetration, stress and fungal defense. Further, we performed a comparative genomic distribution of differentially expressed proteins of the M. anisopliae secretome against another arthropod pathogen, using the Beauveria bassiana ARSEF2860 protein repertory. Among 47 analyzed protein families, thirty were overexpressed in the M. anisopliae E6 predicted genome compared to B. bassiana. An in vivo toxicity assay using a Galleria mellonella model confirmed that the M. anisopliae E6 secretome was more toxic in cattle tick infections compared to other secretomes, including B. bassiana with cattle ticks and M. anisopliae E6 with the insect Dysdereus peruvianus, which our proteomic results had also suggested. These results help explain molecular aspects associated with host infection specificity due to genetic differences and gene expression control at the protein level in arthropod-pathogenic fungi.

The role of glial cells in Zika virus-induced neurodegeneration.

Zika virus (ZIKV) is a strongly neurotropic flavivirus whose infection has been associated with microcephaly in neonates. However, clinical and experimental evidence indicate that ZIKV also affects the adult nervous system. In this regard, in vitro and in vivo studies have shown the ability of ZIKV to infect glial cells. In the central nervous system (CNS), glial cells are represented by astrocytes, microglia, and oligodendrocytes. In contrast, the peripheral nervous system (PNS) constitutes a highly heterogeneous group of cells (Schwann cells, satellite glial cells, and enteric glial cells) spread through the body. These cells are critical in both physiological and pathological conditions; as such, ZIKV-induced glial dysfunctions can be associated with the development and progression of neurological complications, including those related to the adult and aging brain. This review will address the effects of ZIKV infection on CNS and PNS glial cells, focusing on cellular and molecular mechanisms, including changes in the inflammatory response, oxidative stress, mitochondrial dysfunction, Ca2+ and glutamate homeostasis, neural metabolism, and neuron-glia communication. Of note, preventive and therapeutic strategies that focus on glial cells may emerge to delay and/or prevent the development of ZIKV-induced neurodegeneration and its consequences.

In vitro and in vivo anti-inflammatory and anticoagulant activities of Myrciaria plinioides D. Legrand ethanol leaf extract.

Myrciaria plinioides D. Legrand (Myrtaceae) is a native plant of Southern Brazil, which have potential in the food industry due to its edible fruits. Many plants belonging to this genus have been used for a variety of illnesses, including inflammatory disorders due to antioxidant properties. However, therapeutic uses of M. plinioides have been poorly studied. The aim of study was to assess the anti-inflammatory and anticoagulant activities of the ethanol leaf extract of M. plinioides. In M. plinioides extract-treated RAW 264.7 cells, assessments of cell viability, TNF-α release and p38 MAPK pathway-dependent protein expression were detected. In addition, rat paw edema models were used to analyze the anti-inflammatory effect of the extract. Macrophages cell line treated with M. plinioides extract showed a slight decrease in cell viability. In LPS-stimulated macrophages treated with different concentrations of the extract for 24 h, TNF-α release was inhibited, while modulation of p38 signaling pathway and inhibition of NF-κB p65 protein expression were dose-dependent. In rats, the extract inhibited the formation of paw edema, while an inhibitory effect on trypsin-like enzymes derived from mast cells was seen. Furthermore, the extract presented anticoagulant activity via extrinsic pathway, being able to block specifically factor Xa and thrombin. The study suggests that extract possess potent anti-inflammatory and anticoagulant effects. M. plinioides present great biological potential as a source for the development of anti-inflammatory and anticoagulant drugs. Additional studies can be proposed to better elucidate the mechanism by which M. plinioides exerts its effects.

SARSCOVIDB-A New Platform for the Analysis of the Molecular Impact of SARS-CoV-2 Viral Infection.

The COVID-19 pandemic caused by the new coronavirus (SARS-CoV-2) has become a global emergency issue for public health. This threat has led to an acceleration in related research and, consequently, an unprecedented volume of clinical and experimental data that include changes in gene expression resulting from infection. The SARS-CoV-2 infection database (SARSCOVIDB: https://sarscovidb.org/) was created to mitigate the difficulties related to this scenario. The SARSCOVIDB is an online platform that aims to integrate all differential gene expression data, at messenger RNA and protein levels, helping to speed up analysis and research on the molecular impact of COVID-19. The database can be searched from different experimental perspectives and presents all related information from published data, such as viral strains, hosts, methodological approaches (proteomics or transcriptomics), genes/proteins, and samples (clinical or experimental). All information was taken from 24 articles related to analyses of differential gene expression out of 5,554 COVID-19/SARS-CoV-2-related articles published so far. The database features 12,535 genes whose expression has been identified as altered due to SARS-CoV-2 infection. Thus, the SARSCOVIDB is a new resource to support the health workers and the scientific community in understanding the pathogenesis and molecular impact caused by SARS-CoV-2.

COVID-19 impacts the expression of molecular markers associated with neuropsychiatric disorders.

Coronavirus disease 2019 (COVID-19) was initially characterized due to its impacts on the respiratory system; however, many recent studies have indicated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) significantly affects the brain. COVID-19 can cause neurological complications, probably caused by the induction of a cytokine storm, since there is no evidence of neurotropism by SARS-CoV-2. In line with this, the COVID-19 outbreak could accelerate the progression or affect the clinical outcomes of neuropsychiatric conditions. Thus, we analyzed differential gene expression datasets for clinical samples of COVID-19 patients and identified 171 genes that are associated with the pathophysiology of the following neuropsychiatric disorders: alcohol dependence, autism, bipolar disorder, depression, panic disorder, schizophrenia, and sleep disorder. Several of the genes identified are associated with causing some of these conditions (classified as elite genes). Among these elite genes, 9 were found for schizophrenia, 6 for autism, 3 for depression/major depressive disorder, and 2 for alcohol dependence. The patients with the neuropsychiatric conditions associated with the genes identified may require special attention as COVID-19 can deteriorate or accelerate neurochemical dysfunctions, thereby aggravating clinical outcomes.

Urine proteomic analysis reveals alterations in heme/hemoglobin and aminopeptidase metabolism during Lonomia obliqua venom-induced acute kidney injury.

AIMS: Accidental contact with the Lonomia obliqua caterpillar is a common event in southern Brazil. Envenomed victims present consumption coagulopathy, which can evolve to acute kidney injury (AKI). In the present study, we searched for AKI biomarkers and changes in molecular pathway signatures through urine proteomic analysis. METHODOLOGY: Male Wistar rats were injected with L. obliqua venom (1.5 mg/kg, via s.c.) or 0.9 % NaCl and distributed into metabolic cages. After 24 h, urine was obtained, and the set of differentially regulated proteins was analyzed by MudPIT technology in an OrbiTRAP mass spectrometer. RESULTS: L. obliqua venom leads to an increase in urine output and water and electrolyte excretion and to an increase in the albumin to creatine ratio in urine. The proteomic analysis revealed an up-regulation of tubular injury biomarkers, such as neutrophil-gelatinase associated lipocalin (NGAL) and cystatin C, in urine from envenomed rats. Several components related to the heme scavenging system were up-regulated or exclusively identified in urine from envenomed animals. There was an increase in urinary heme levels and hemoglobin subunits, hemopexin, haptoglobin, and biliverdin reductase. Similarly, kinin- and angiotensin-generating/degrading peptidases, such as kallikreins, neprilysin, plasmin, dipeptidyl peptidase IV, cathepsin D, kininogen, and neutral, basic, glutamyl, and acidic aminopeptidases, were also up-regulated in urine. CONCLUSIONS: L. obliqua envenomation induced tubular and glomerular injury, probably involving heme/hemoglobin toxicity and an imbalance in the kinin/angiotensin generating/degrading system.

Kallikrein-kinin system and oxidative stress in cisplatin-induced ovarian toxicity.

Kallikrein-kinin system (KKS) is involved in vascular reactivity and inflammatory response to cytotoxic drugs. Since cisplatin is a widely used chemotherapy and its cytotoxic mechanism can trigger inflammation and oxidative damage, in this work we evaluated the role of KKS in an animal model of cisplatin-induced ovarian toxicity. Biomarkers of ovarian stem cells, activity of KKS, inflammation and oxidative damage were measured in ovarian tissue of C57BL/6 female mice treated with vehicle or cisplatin (2.5 mg/kg). Cisplatin group presented greater number of atretic follicles, and lower numbers of antral and total viable follicles. Ki67, DDX4 and OCT-4 markers were similar between groups. Cisplatin triggered plasma and ovarian tissue kallikrein generation; and increased expression of bradykinin receptors B1 and B2. Neutrophil and macrophage infiltration markers increased. Superoxide anion generation also increased, while reduced glutathione levels decreased. These results suggest that KKS is activated and contributes to ovarian injury during cisplatin treatment.

Renal and vascular effects of kallikrein inhibition in a model of Lonomia obliqua venom-induced acute kidney injury.

BACKGROUND: Lonomia obliqua venom is nephrotoxic and acute kidney injury (AKI) is the main cause of death among envenomed victims. Mechanism underlying L. obliqua-induced AKI involves renal hypoperfusion, inflammation, tubular necrosis and loss of glomerular filtration and tubular reabsorption capacities. In the present study, we aimed to investigate the contribution of kallikrein to the hemodynamic instability, inflammation and consequent renal and vascular impairment. METHODOLOGY/PRINCIPAL FINDINGS: Addition of L. obliqua venom to purified prekallikrein and human plasma in vitro or to vascular smooth muscle cells (VSMC) in culture, was able to generate kallikrein in a dose-dependent manner. Injected in rats, the venom induced AKI and increased kallikrein levels in plasma and kidney. Kallikrein inhibition by aprotinin prevented glomerular injury and the decrease in glomerular filtration rate, restoring fluid and electrolyte homeostasis. The mechanism underlying these effects was associated to lowering renal inflammation, with decrease in pro-inflammatory cytokines and matrix metalloproteinase expression, reduced tubular degeneration, and protection against oxidative stress. Supporting the key role of kallikrein, we demonstrated that aprotinin inhibited effects directly associated with vascular injury, such as the generation of intracellular reactive oxygen species (ROS) and migration of VSMC induced by L. obliqua venom or by diluted plasma obtained from envenomed rats. In addition, kallikrein inhibition also ameliorated venom-induced blood incoagulability and decreased kidney tissue factor expression. CONCLUSIONS/SIGNIFICANCE: These data indicated that kallikrein and consequently kinin release have a key role in kidney injury and vascular remodeling. Thus, blocking kallikrein may be a therapeutic alternative to control the progression of venom-induced AKI and vascular disturbances.

HCPA 48 anos: destaque na produção científica / 48 years of HCPA: prominence in academic research

Este artigo ilustra o desenvolvimento das atividades de pesquisa ao longo dos 48 anos do Hospital de Clínicas de Porto Alegre (HCPA). Fundado em 1971, o HCPA começa a atuar em pesquisa em 1974, data dos primeiros artigos indexados nas bases internacionais. O estudo abrange um período de 44 anos, de 1974 a 2018, para o qual foram levantados os artigos científicos publicados em periódicos indexados na base Web of Science por pesquisadores do próprio hospital, da Faculdade de Medicina e de outras unidades da UFRGS associados aos projetos de pesquisa do HCPA. O artigo resulta de um estudo cientométrico, sendo para tanto realizadas análises de indicadores bibliográficos, como produção total de artigos científicos experimentais, artigos de revisão e artigos completos em eventos (proceedings papers). Para facilidade de informação, os termos utilizados pelas bases foram mantidos em inglês ao longo do texto e nas tabelas e figuras. Um total de 6.383 documentos desses três tipos de artigos foi publicado no período. Mostra-se também a evolução temporal dessa produção. Foram ainda levantadas as principais áreas de pesquisa, as palavraschave dos artigos, as revistas, a colaboração internacional e menção aos trabalhos mais citados. Ao longo do estudo foi possível verificar que alguns pesquisadores, autores de trabalhos significativos, não indicam nos artigos sua vinculação ao HCPA e recomenda-se uma orientação do GPPG sobre o assunto. (AU)

This article illustrates the development of research activities over the 48 years of the Hospital de Clínicas de Porto Alegre (HCPA). Founded in 1971, the HCPA begins its research activities in 1974, date of the first articles published in indexed journals. The study covers a period of 44 years, from 1974 to 2018 for which the scientific articles in journals indexed in the Web of Science database, published by researchers of the hospital including the Faculty of Medicine and other UFRGS units associated with the research projects of the HCPA were considered for this study. The article results from a scientometric study, and for this purpose analyzes of bibliographic indicators were carried out, covering: total production of experimental scientific articles, review articles and complete papers published in the proceedings of scientific events. For ease of information, the terms used by the bases were maintained in English throughout the text and in the tables and figures. A total of 6,383 documents of these three types of articles were published in the period. The temporal evolution of this production is also shown. The main research areas, the keywords of the articles, the journals, the international collaboration and the most cited papers were also raised. It was identified at the end that several authors though working in the hospital, do not indicate in the articles their linkage to the HCPA and thus, it is recommended to GPPG to develop some orientation to the researchers concerning to this subject. (AU)

ZIKA Virus and Neuroscience: the Need for a Translational Collaboration.

Zika virus (ZIKV) has become a major challenge for scientists and health agencies. ZIKV's involvement with human fetal microcephaly and Guillain-Barré syndrome and its transmission through Aedes africanus and Aedes aegypti mosquitos highlighted the epidemiological and neurological risks associated to ZIKV infection. In 2013, ZIKV arrives in Brazil but the first outbreak in the country was reported in 2015. Here, we used the Web of Science as a search tool for comparing the evolution of world and Brazilian scientific research on dengue virus (DENV)-also present in mosquito-, ZIKV and microcephaly. The association between ZIKV and microcephaly was only evidenced in 2015. Interestingly, Brazil and the USA are the responsible for most of these reports. Furthermore, the level of double-counted articles indicates a high degree of international collaborative effort in studying ZIKV and microcephaly. The ZIKV research clearly requires multidisciplinary expertise including epidemiologic, clinical, virological, and neurochemical backgrounds. This letter intends to emphasize the need of multidisciplinary studies and put forward some as yet unanswered questions in attempting to contribute to the understanding of this multifaceted health problem. In line with this, we recently constituted a collaborative and multidisciplinary taskforce encompassing eight Brazilian scientific institutions of excellence, The ZIKV translational research taskforce. This taskforce comprises a vast international network of collaborators and welcomes additional collaborators. We intend to advance fast in terms of mechanisms, which can potentially contribute to treat or halt ZIKV spreading around the world.

Effects of Lonomia obliqua Venom on Vascular Smooth Muscle Cells: Contribution of NADPH Oxidase-Derived Reactive Oxygen Species.

Envenomation caused by human contact with the caterpillar Lonomia is characterized by deleterious effects on coagulation and patency of blood vessels. The cellular effects induced by Lonomia obliqua venom highlights its capacity to activate endothelial cells, leading to a proinflammatory phenotype. Having more knowledge about the mechanisms involved in envenomation may contribute to better treatment. We aimed to evaluate the effects of Lonomia obliqua caterpillar bristle extract (LOCBE) on vascular smooth muscle cells (VSMC). We observed that LOCBE induced VSMC migration, which was preceded by alterations in actin cytoskeleton dynamics and Focal Adhesion Kinase activation. LOCBE also induced Extracellular Signal-Regulated Kinase (ERK) phosphorylation in VSMC, and the inhibition of this pathway impaired cell proliferation. Stimulation of VSMC with LOCBE triggered reactive oxygen species (ROS) production through the activation of NADPH oxidase. The rapid increase in these ROS further induced mitochondrial ROS production, however only NADPH oxidase-derived ROS were involved in ERK activation in VSMC. We that demonstrated the chemotactic and proliferative effects of LOCBE on VSMC were dependent on ROS production, mainly through NADPH oxidase. Together, the data show that Lonomia obliqua venom can interact with and activate VSMC. These effects rely on ROS production, suggesting new potential targets for treatment against vascular damage during envenomation.

Produção científica na área de neurociência e comportamento indexada na base de dados web of science / Scientific production in neuroscience and behavior indexed in the web of science database / Producción científica en neurociencia y comportamiento indexada en la base de datos web of science

Este artigo baseia-se em um estudo cientométrico e apresenta os principais aspectos da produção científica brasileira na área de neurociência e comportamento indexada em comparação com a de outros países. Considerou-se como produção científica: artigos, artigos de revisão e notas indexados na base de dados Web of Science (WoS), no período de 2010 a 2014. Foram utilizadas também informações sobre grupos de pesquisa do CNPq extraídas do Diretório dos Grupos de Pesquisa e também de Programas de Pós Graduação avaliados pela Capes obtidas na base Geocapes no período, mostrando um crescimento da área.

This article is a scientometric study that presents the main aspects of the indexed Brazilian scientific production in neuroscience and behavior compared to other countries. As scientific production indicators are included: articles, reviews and notes indexed in the Web of Science (WoS) database from 2010 to2014. Moreover, information about CNPq research groups drawn from Diretório dos Grupos de Pesquisa (Research Group Directory) and from Postgraduate Programs evaluated by Capes extracted from Geocapes shows an increase in neuroscience and behavior area.

El artículo se caracteriza como estudio cientométrico y presenta los principales aspectos de la producción científica brasileña en neurociencia y comportamiento indexada en comparada con aquella de otros países. Se consideró como la producción científica: artículos, artículos de revisión y notas indexados en la base de datos Web of Science (WoS) en el periodo de 2010-2014. Se utilizaron también informaciones acerca de los grupos de investigación del CNPq extraídas del Diretório dos Grupos de Pesquisa (Directorio de losgrupos de investigación) y también de Programas de postgrados evaluados por la Capes obtenidas de labase Geocapes, mostrando un crecimiento en la area.de neurociencia y comportamiento.

Mechanisms of acute kidney injury induced by experimental Lonomia obliqua envenomation.

Lonomia obliqua caterpillar envenomation causes acute kidney injury (AKI), which can be responsible for its deadly actions. This study evaluates the possible mechanisms involved in the pathogenesis of renal dysfunction. To characterize L. obliqua venom effects, we subcutaneously injected rats and examined renal functional, morphological and biochemical parameters at several time points. We also performed discovery-based proteomic analysis to measure protein expression to identify molecular pathways of renal disease. L. obliqua envenomation causes acute tubular necrosis, which is associated with renal inflammation; formation of hematic casts, resulting from intravascular hemolysis; increase in vascular permeability and fibrosis. The dilation of Bowman's space and glomerular tuft is related to fluid leakage and intra-glomerular fibrin deposition, respectively, since tissue factor procoagulant activity increases in the kidney. Systemic hypotension also contributes to these alterations and to the sudden loss of basic renal functions, including filtration and excretion capacities, urinary concentration and maintenance of fluid homeostasis. In addition, envenomed kidneys increase the expression of proteins involved in cell stress, inflammation, tissue injury, heme-induced oxidative stress, coagulation and complement system activation. Finally, the localization of the venom in renal tissue agrees with morphological and functional alterations, suggesting also a direct nephrotoxic activity. In conclusion, the mechanisms of L. obliqua-induced AKI are complex involving mainly glomerular and tubular functional impairment and vascular alterations. These results are important to understand the mechanisms of renal injury and may suggest more efficient ways to prevent or attenuate the pathology of Lonomia's envenomation.

Acute Lonomia obliqua caterpillar envenomation-induced physiopathological alterations in rats: evidence of new toxic venom activities and the efficacy of serum therapy to counteract systemic tissue damage.

The clinical manifestations of Lonomia obliqua caterpillar envenomation are systemic hemorrhage and acute kidney injury. In an effort to better understand the physiopathological mechanisms of envenomation, a rat model was established to study systemic tissue damage during L. obliqua envenomation. An array of acute venom effects was characterized, including biochemical, hematological, histopathological, myotoxic and genotoxic alterations. Rapid increases in serum alanine and aspartate transaminases, γ-glutamyl transferase, lactate dehydrogenase, hemoglobin, bilirubin, creatinine, urea and uric acid were observed, indicating that intravascular hemolysis and liver and kidney damage had occurred. Treatment with a specific antivenom (antilonomic serum) for up to 2 h post-venom injection neutralized the biochemical alterations. However, treatment after 6 h post-venom injection failed to normalize all biochemical parameters, despite its efficacy in reversing coagulation dysfunction. The hematological findings were consistent with hemolytic anemia and neutrophilic leukocytosis. The histopathological alterations were mainly related to hemorrhage and inflammation in the subcutaneous tissue, lung, heart and kidneys. Signs of congestion and hemosiderosis were evident in the spleen, and hemoglobin and/or myoglobin casts were also detected in the renal tubules. Increased levels of creatine kinase and creatine kinase-MB were correlated with the myocardial necrosis observed in vivo and confirmed the myotoxicity detected in vitro in isolated extensor digitorum longus muscles. Significant DNA damage was observed in the kidneys, heart, lung, liver and lymphocytes. The majority of the DNA lesions in the kidney were due to oxidative damage. The results presented here will aid in understanding the pathology underlying Lonomia's envenomation.

Antithrombotic effect of chikusetsusaponin IVa isolated from Ilex paraguariensis (Maté).

The triterpene chikusetsusaponin IVa was isolated from the fruit of Ilex paraguariensis. Using biochemical and pharmacological methods, we demonstrated that chikusetsusaponin IVa (1) prolongs the recalcification time, prothrombin time, activated partial thromboplastin time, and thrombin time of normal human plasma in a dose-dependent manner, (2) inhibits the amidolytic activity of thrombin and factor Xa upon synthetic substrates S2238 and S2222, (3) inhibits thrombin-induced fibrinogen clotting (50% inhibition concentration, 199.4 ± 9.1 µM), and (4) inhibits thrombin- and collagen-induced platelet aggregation. The results also indicate that chikusetsusaponin IVa preferentially inhibits thrombin in a competitive manner (K(i)=219.6 µM). Furthermore, when administered intravenously to rats, chikusetsusaponin IVa inhibited thrombus formation in a stasis model of venous thrombosis, although it did not induce a significant bleeding effect. Chikusetsusaponin IVa also prolonged the ex vivo activated partial thromboplastin time. Altogether, these data suggest that chikusetsusaponin IVa exerts antithrombotic effects, including minor hemorrhagic events. This appears to be important for the development of new therapeutic agents.

Thrombin allosteric modulation revisited: a molecular dynamics study.

The regulatory properties of thrombin are derived predominantly from its capacity to produce different functional conformations. Functional studies have revealed that two antagonistic thrombin conformations exist in equilibrium: the fast (procoagulant) and slow (anticoagulant) forms. The mechanisms whereby thrombin activity is regulated by the binding of different effectors remain among the most enigmatic and controversial subjects in the field of protein function. In order to obtain more detailed information on the dynamic events originating from the interaction with the Na(+) effector and ligand binding at the active site and anion binding exosite 1 (ABE1), we carried out molecular dynamics simulations of thrombin in different bound states. The results indicated that Na(+) release results in a more closed conformation of thrombin, which can be compared to the slow form. The conformational changes induced by displacement of the sodium ion from the Na-binding site include: (1) distortion of the 220- and 186-loops that constitute the Na-binding site; (2) folding back of the Trp148 loop towards the body of the protein, (3) a 180 degrees rotation of the Asp189 side-chain, and (4) projection of the Trp60D loop toward the solvent accompanied by the rearrangement of the Trp215 side chain toward the 95-100 loop. Our findings correlate well with the known structural and recognition properties of the slow and fast forms of thrombin, and are in accordance with the hypothesis that there is communication between the diverse functional domains of thrombin. The theoretical models generated from our MD simulations complement and advance the structural information currently available, leading to a more detailed understanding of thrombin structure and function.

Antilonomic effects of Brazilian brown seaweed extracts.

The aim of this work was to investigate the hemolysis and blood clotting activity of Lomonia obliqua venom and the ability of some Brazilian marine algal extracts (Canistrocarpus cervicornis, Stypopodium zonale and Dictyota pfaffi) to antagonize such biological activities. L. obliqua caterpillars are dangerous to human beings and envenomation symptoms are characterized by hemorrhagic, hemolytic and blood clotting disorders, and acute renal failure, which sometimes lead to the death of the victims. Through in vitro experiments we have shown that L. obliqua venom is able to clot human plasma and hemolize human erythrocytes and that the coagulation activity of the venom is inhibited by the extracts of C. cervicornis, S. zonale and D. pfaffi. In contrast, C. cervicornis and S. zonale extracts did not inhibit the hemolytic activity of L. oblqua, as did the extract of D. pfaffi. These finding indicate that marine algae may be used as antivenoms or may contribute to the development of compounds with antilonomic effects.

Characterization of the papillomavirus alpha(1)E2 peptide unfolded to folded transition upon DNA binding.

Transcriptional regulation depends on sequence-specific binding of regulatory proteins to their responsive elements in viral DNA. The papillomavirus E2 protein binds to DNA through the consensus sequence ACCG-NNNN-CGGT, activating or inhibiting viral replication. Through molecular dynamics simulations we were able to characterize the role of the DNA molecule on E2 binding region (named alpha(1)E2) conformation, acquiring structural insights for previous works suggesting an unfolded to folded transition upon alpha(1)E2 complexation to DNA. Moreover, the results indicate sites to guide the design of alpha(1)E2 synthetic derivatives to inhibit the HPV infection.

Lonofibrase, a novel alpha-fibrinogenase from Lonomia obliqua caterpillars.

Envenomation caused by Lonomia obliqua caterpillars is an increasing problem in Southern Brazil. The clinical profile is characterized by a profound hemorrhagic disorder. In the present study, we describe the characterization of a fibrin(ogen)olytic factor (lonofibrase) isolated from a venomous secretion of the caterpillars. The crude extract showed a dose-dependent inhibitory effect in the rate of thrombin-induced fibrinogen clotting and produced fragmentation of fibrinogen. Isolation of the fibrin(ogen)olytic enzyme was achieved by combining ion exchange chromatography followed by gel filtration in a fast protein liquid chromatography (FPLC) system. A single 35-kDa band was identified and the isolated enzyme named lonofibrase. Lonofibrase rapidly degrades Aalpha and Bbeta chains of fibrinogen, also being able to cleave fibrin in a distinct way from that observed with plasmin. The presence of lonofibrase with both fibrinogenolytic and fibrinolytic activities in L. obliqua secretion is coherent with the severe hemorrhagic clinical profile resulting from envenomation caused by these insects.