In Vitro Identification of Novel Plasminogen-Binding Receptors of the Pathogen Leptospira interrogans

Background: Leptospirosis is a multisystem disease caused by pathogenic strains of the genus Leptospira. We have reported that Leptospira are able to bind plasminogen (PLG), to generate active plasmin in the presence of activator, and to degrade purified extracellular matrix fibronectin. Methodology/Principal Findings: We have now cloned, expressed and purified 14 leptospiral recombinant proteins. The proteins were confirmed to be surface exposed by immunofluorescence microscopy and were evaluated for their ability to bind plasminogen (PLG). We identified eight as PLG-binding proteins, including the major outer membrane protein LipL32, the previously published rLIC12730, rLIC10494, Lp29, Lp49, LipL40 and MPL36, and one novel leptospiral protein, rLIC12238. Bound PLG could be converted to plasmin by the addition of urokinase-type PLG activator (uPA), showing specific proteolytic activity, as assessed by its reaction with the chromogenic plasmin substrate, D-Val-Leu-Lys 4-nitroanilide dihydrochloride. The addition of the lysine analog 6-aminocaproic acid (ACA) inhibited the protein-PLG interaction, thus strongly suggesting the involvement of lysine residues in plasminogen binding. The binding of leptospiral surface proteins to PLG was specific, dose-dependent and saturable. PLG and collagen type IV competed with LipL32 protein for the same binding site, whereas separate binding sites were observed for plasma fibronectin. Conclusions/Significance: PLG-binding/activation through the proteins/receptors on the surface of Leptospira could help the bacteria to specifically overcome tissue barriers, facilitating its spread throughout the host.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico)Fundacao Butantan, BrazilFAPESP (Brazil

Manicômio em circuito: os percursos dos jovens e a internação psiquiátrica The psychiatric hospital circuit: the trajectories of yong people prior to psychiatric hospitalization

Este artigo analisa a internação psiquiátrica de jovens, tomando-a não a partir de uma perspectiva psicopatológica individual, mas de uma dimensão subjetivo-social com base nos percursos desses jovens até a internação. O estudo foi realizado no Centro Integrado de Atenção Psicossocial para crianças e adolescentes do Hospital Psiquiátrico São Pedro, na cidade de Porto Alegre, Rio Grande do Sul, Brasil, por meio de oficinas com os jovens que estavam em atendimento na internação deste serviço. Percebeu-se uma recorrência que marca o percurso desses jovens e expressa um determinado modo de funcionamento da rede de atenção até a internação, acarretando na produção de um certo perfil desses jovens: pobreza sócio-econômica, baixa escolaridade e uso de drogas. Outro aspecto importante é o papel da ordem judicial nos encaminhamentos à internação, que obedece tanto a uma lógica de punição aos jovens e aos serviços, como também, paradoxalmente, constitui-se numa estratégia de acesso aos serviços de saúde.<br>This article analyzes psychiatric hospitalization of young patients from a contemporary social-subjective (rather than a psychopathological) perspective, following the trajectory of these youth prior to their admission. The study was conducted at the Center for Comprehensive Psychosocial Care for Children and Adolescents, São Pedro Psychiatric Hospital, in the city of Porto Alegre, Rio Grande do Sul State, Brazil. Recurrent traits in the trajectory of these youth expressed how the health care network functioned with them prior to their hospitalization, with a consistent pattern of socioeconomic deprivation, low schooling, and drug use. Another key aspect was the role of the court system in referring them for hospitalization, adhering to a kind of logic that punished both the youth and the services and paradoxically formed a strategy for access to health services

A novel ruthenium complex with xanthoxylin induces S-phase arrest and causes ERK1/2-mediated apoptosis in HepG2 cells through a p53-independent pathway

Abstract Ruthenium-based compounds have gained great interest due to their potent cytotoxicity in cancer cells; however, much of their potential applications remain unexplored. In this paper, we report the synthesis of a novel ruthenium complex with xanthoxylin (RCX) and the investigation of its cellular and molecular action in human hepatocellular carcinoma HepG2 cells. We found that RCX exhibited a potent cytotoxic effect in a panel of cancer cell lines in monolayer cultures and in a 3D model of multicellular cancer spheroids formed from HepG2 cells. This compound is detected at a high concentration in the cell nuclei, induces DNA intercalation and inhibits DNA synthesis, arresting the cell cycle in the S-phase, which is followed by the activation of the caspase-mediated apoptosis pathway in HepG2 cells. Gene expression analysis revealed changes in the expression of genes related to cell cycle control, apoptosis and the MAPK pathway. In addition, RCX induced the phosphorylation of ERK1/2, and pretreatment with U-0126, an MEK inhibitor known to inhibit the activation of ERK1/2, prevented RCX-induced apoptosis. In contrast, pretreatment with a p53 inhibitor (cyclic pifithrin-α) did not prevent RCX-induced apoptosis, indicating the activation of a p53-independent apoptosis pathway. RCX also presented a potent in vivo antitumor effect in C.B-17 SCID mice engrafted with HepG2 cells. Altogether, these results indicate that RCX is a novel anticancer drug candidate