Suppression of nitrosative stress and inflammation of the knee joint synovium in collagen type ii-induced rheumatoid arthritis by the inhibition of glycogen synthase kinase-3ß / Supresión del estrés nitrosativo e inflamación de la sinovial de la articulación de la rodilla en la artritis reumatoide inducida por colágeno tipo ii mediante la inhibición de la glucógeno sintasa quinasa-3 ß

SUMMARY: Rheumatoid arthritis (RA), an inflammatory autoimmune disease that causes cartilage degradation and tissue destruction, can affect synovial joints such as the knee joint. The link between the nitrosative stress enzyme inducible nitric oxide synthase (iNOS) and the cytokine interleukin-1 (IL-1β) in RA-induced knee joint synovial membrane damage with and without the incorporation of the GSK3β inhibitor TDZD-8 has never been studied. As a result, we used active immunization method with collagen type II (COII) for twenty one days to induce RA in rats. TDZD-8 (1 mg/kg; i.p.) was given daily into matched immunized rats for three weeks after day 21 (COII+TDZD-8). Blood and tissue samples were taken 42 days after immunization. A dramatic increase in rheumatoid factor (RF) blood levels, as well as considerable synovial tissue damage and inflammatory cell infiltration of the synovial membrane, were used to validate the onset of RA following COII immunization. COII immunization increased tissue levels of iNOS protein and IL- 1β mRNA and protein expression, which TDZD-8 suppressed considerably (p<0.0001). Furthermore, there was a significantly (p<0.001) positive correlation between iNOS, inflammatory biomarkers, and RF. We concluded that TDZD-8 reduced RA-induced IL-1β -iNOS axis-mediated arthritis in the rat knee joint synovium.

RESUMEN: La artritis reumatoide (AR), es una enfermedad autoinmune inflamatoria que causa la degradación del cartílago y la destrucción del tejido, pudiendo afectar las articulaciones sinoviales, como la articulación de la rodilla. No se ha estudiado el vínculo entre la óxido nítrico sintasa inducible por la enzima del estrés nitrosativo (iNOS) y la citocina interleucina-1 (IL-1β) en el daño de la membrana sinovial de la articulación de la rodilla provocado por AR con y sin la incorporación del inhibidor de GSK3β TDZD-8. Utilizamos el método de inmunización activa con colágeno tipo II (COII) durante veintiún días para inducir AR en ratas. Se administró TDZD-8 (1 mg/kg; i.p.) diariamente a ratas inmunizadas emparejadas durante tres semanas después del día 21 (COII+TDZD- 8). Se tomaron muestras de sangre y tejido 42 días después de la inmunización. Se observó un gran aumento de los niveles sanguíneos del factor reumatoideo (FR), así como un daño considerable del tejido sinovial e infiltración de células inflamatorias en la membrana sinovial, para validar la aparición de la AR después de la inmunización con COII. La inmunización con COII aumentó los niveles tisulares de la proteína iNOS y la expresión de proteína y ARNm de IL-1β, que TDZD-8 suprimió considerablemente (p<0,0001). Además, hubo una correlación positiva significativa (p<0,001) entre iNOS, biomarcadores inflamatorios y FR. Concluimos que TDZD- 8 redujo la artritis mediada por el eje IL-1β-iNOS inducida por la AR en la sinovial de la articulación de la rodilla de rata.

Explorando os estresses oxidativo e nitrosativo contra fungos: um mecanismo subjacente à ação de tradicionais antifúngicos e um potencial novo alvo terapêutico na busca por indutores oriundos de fontes naturais / Explorando los estréses oxidativos y nitrosativos contra hongos: un mecanismo subyacente a la acción de los antifúngicos tradicionales y un potencial nuevo objetivo terapéutico en la búsqueda de inductores de fuentes naturales / Exploring the oxidative and nitrosative stresses against fungi: an underlying mechanism beyond the action of traditional antifungal agents and a potential new therapeutic target in searching for inducers from natural sources

RESUMO Objetivo: Nesta revisão sistemática, nós avaliamos o link entre indutores de estresse oxidativo e/ou nitrosativo (EO/EN) com atividade antifúngica, através de uma ação direta sobre a célula fúngica e/ou modulando a resposta de fagócitos contra fungos de interesse médico (incluindo Candida spp., Cryptococcus spp. e Aspergillus spp.). Ainda, foram avaliadas as implicações clínicas deste evento bioquímico, bem como as perspectivas quanto à busca por novos compostos com atividade antifúngica, principalmente, os provenientes de fonte natural e, que explorem a indução de um EO ou EN como parte de seu mecanismo de ação. Metodologia: Foram avaliados artigos, provenientes de diferentes bases de dados e publicados a qualquer período, acessados entre abril e junho de 2017, através da utilização de diferentes descritores. Resultados: Primeiramente, estabelecemos as definições de EO/EN, como sendo o aumento das concentrações de espécies reativas do oxigênio e/ou nitrogênio (ERO/ ERN) quantificado diretamente e, provenientes de fontes fúngicas mitocondriais, Reação de Fenton, retículo endoplasmático ou outras não definidas, e excedendo a capacidade de defesa antioxidante do microrganismo (avaliados por análises de perfis transcriptômicos ou proteômicos ou metabolômicos ou níveis de atividade enzimática). Este aumento de ERO/ERN causando EO/EN é definido por tempo e condições que conduzem a sinalização de apoptose ou reais danos a biomoléculas com perda de função (peroxidação lipídica ou oxidação proteica ou danos ao DNA) e, consequentemente, gerando morte fúngica ou outro efeito antifúngico associado. Portanto, 64 artigos (apenas um publicado antes do ano 2000 e 50 entre 2007-2017) abordam que a indução de EO ou EN na célula fúngica é parte do mecanismo de ação de clássicos agentes antifúngicos (22 publicações), tais como azóis (fluconazol, itraconazol e miconazol), polienos (anfotericina B [AnB]) e equinocandinas (mica-fungina), assim como tal modulação redox tem sido reportada como um importante alvo terapêutico na busca por novos e promissores compostos naturais com atividade antifúngica (32 publicações), que tem respaldo pela grande variedade de indutores que podem provir da natureza. Ainda, compostos que também induzem o burst oxidativo de fagócitos, incluindo AnB, são potencializadores do efeito antifúngico in vivo. Além do efeito antifúngico contra células planctônicas, os efeitos dos EO ou EN sobre biofilmes fúngicos, também têm sido reportados. Tem sido firmado na literatura recente um claro link entre EO ou EN e a atividade antifúngica, tanto para aqueles agentes antifúngicos já utilizados na terapêutica em humanos, quanto para possíveis candidatos a fármaco. Portanto, a indução do EO ou EN como parte do mecanismo de ação de antifúngicos demonstra ser um importante alvo terapêutico, com perspectivas favoráveis sobre os desfechos na prática clínica.

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SUMMARY Aim: In this systematic review, we evaluated the link between inducers of oxidative or nitrosative stresses (OS/NS) and antifungal activity against fungi of medical relevance (including Candida spp., Cryptococcus spp., and Aspergillus spp.), through a direct action on the fungal cell or modulating phagocyte response. Moreover, the clinical implications of this biochemical event, as well as the perspectives, were examined, highlighting the search for new compounds with antifungal activity, mainly those from natural sources and, which explores the induction of OS or NS as part of the mechanism of action. Methodology: Articles from different databases and published at any time were evaluated, between April and June 2017, and using different descriptors. Results: First, a definition of OS and NS was established in which an increase in reactive oxygen or nitrogen species (ROS/ RNS, quantified directly and from mitochondrial, Fenton reaction, endoplasmic reticulum or other fungal sources) should exceed the antioxidant defense capacity of the microorganism (evaluated by transcriptomic or proteomic or metabolomic profiles or enzyme activity levels). These events, by time and conditions delimited, can lead to the signaling of apoptosis or an actual damage toward biomolecules (lipid peroxidation or protein oxidation or DNA damage) and, consequently, they can cause cell death or other associated antifungal effect. Therefore, 64 articles were found, of these, only one was published before 2000 and 50 between 20072017, reporting the induction of OS or NS directly into the fungal cell via an increase in ROS or RNS as part of the mechanism of action of classical antifungal agents (22 publications), such as: azoles (fluconazole, itraconazole, and miconazole), polyenes (amphotericin B, [AnB]), and echinocandins (micafungin). This redox modulation has also been reported as an important therapeutic target in the search for new natural compounds with antifungal activity (32 publications), which is supported for the great variety of inducers from nature. Compounds that also induce the oxidative burst of phagocytes, including AnB, promote a combinatorial antifungal effect in vivo. In addition to the antifungal effect against plank-tonic cells, the relation between OS or NS and antifungal activity against fungal biofilms has also been reported. It has been established in the recent literature a clear link between OS or NS and antifungal effect, during the action of anti-fungal agents already used in the therapy in humans as well as for possible drug candidates. Thus, the induction of OS or NS as part of the mechanism of action proves to be an important therapeutic target with favorable perspectives on the outcomes in clinical practice.

Induction of brain injury and depression in rats by chronic unpredictable stress associated with the augmentation of nitrosative stress and apoptosis / Inducción de lesión cerebral y depresión en ratas por estrés crónico impredecible asociado con el aumento del estrés nitrosativo y la apoptosis

SUMMARY: Repeated stress is a risk factor for memory impairment and neurological abnormalities in both humans and animals. We sought to investigate the extent of (i) brain tissue injury; (ii) nitrosative and oxidative stress in brain tissue homogenates; (iii) apoptotic and survival biomarkers in brain tissue homogenates; and (iv) immobility and climbing abilities, induced over a period of three weeks by chronic unpredictable stress (CUS). Wistar rats were either left untreated (Control group) or exposed to a variety of unpredictable stressors daily before being sacrificed after 3 weeks (model group). Assessment of depression-like behavior was performed and animals were then culled and harvested brain tissues were stained with basic histological staining and examined under light microscopy. In addition, brain tissue homogenates were prepared and assayed for these parameters; inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), superoxide dismutase (SOD), caspase-3, and B-cell lymphoma 2 (Bcl-2). Histology images showed CUS induced profound damage to the cerebral cortex as demonstrated by severe neuronal damage with shrunken cells, disrupted atrophic nuclei, perineuronal vacuolation and swollen glial cells. CUS also significantly (p<0.05) induced iNOS, MDA, and caspase-3, whereas SOD and Bcl-2 brain tissue levels were inhibited by CUS. In addition, data from the depression-like behavior, forced swimming test showed significant (p<0.05) increase in animal immobility and decrease in climbing ability in the model group of rats. Thus, here we demonstrated a reliable rat model of chronic stress-induced brain injury, which can further be used to investigate beneficial drugs or agents used for a period of three weeks to protect against CUS-induced brain damage.

RESUMEN: El estrés crónico es un factor de riesgo para el deterioro de la memoria y las anomalías neurológicas tanto en humanos como en animales. Intentamos investigar el alcance de lesión del tejido cerebral; (ii) estrés nitrosativo y oxidativo en homogeneizados de tejido cerebral; (iii) biomarcadores apoptóticos y de supervivencia en homogeneizados de tejido cerebral; y (iv) inmovilidad y habilidades de escalada, inducidas durante un período de tres semanas por estrés crónico impredecible (ECI). Se dejaron sin tratamiento (grupo control) ratas Wistar, o se expusieron a una variedad de factores estresantes impredecibles diariamente antes de ser sacrificadas después de 3 semanas (grupo modelo). Se realizó una evaluación del comportamiento similar a la depresión y luego se sacrificaron los animales y se tiñeron los tejidos cerebrales con tinción histológica básica y se examinaron con microscopía óptica. Además, se prepararon homogeneizados de tejido cerebral y se analizaron los siguientes parámetros; óxido nítrico sintasa inducible (iNOS), malondialdehído (MDA), superóxido dismutasa (SOD), caspasa- 3 y linfoma de células B 2 (Bcl-2). Las imágenes histológicas mostraron que el CUS indujo un daño profundo en la corteza cerebral como lo demuestra el daño neuronal severo con células encogidas, núcleos atróficos alterados, vacuolación perineuronal y células gliales inflamadas. ECI también indujo significativamente (p <0,05) iNOS, MDA y caspase-3, mientras que los niveles de tejido cerebral SOD y Bcl-2 fueron inhibidos por ECI. Además, los datos del comportamiento similar a la de- presión, la prueba de natación forzada mostró un aumento significativo (p <0,05) en la inmovilidad animal y una disminución en la capacidad de escalada en el grupo modelo de ratas. Por lo tanto, aquí demostramos un modelo confiable de daño cerebral crónico en rata inducido por el estrés, que se puede utilizar para investigar medicamentos o agentes beneficiosos usados durante un período de tres semanas para proteger el daño cerebral inducido por ECI.

Evidencias de la participación del peroxinitrito en diversas enfermedades / Role of peroxynitrite anion in different diseases

Peroxynitrite (ONOO-) is a reactive nitrogen specie produced by the reaction between nitric oxide (NO• ) and super-oxide anion (O2.-). NO• is produced by nitric oxide synthase (NOS) and O2.- is formed by the addition of an electron to O2 in enzymatic as well as nonenzymatic way. NADPH oxidase and xanthine oxidase are some of the enzymes involved in O2.-formation. ONOO- is an oxidant specie which is able to modify a great number of biomolecules such as aminoacids, proteins, enzymes and cofactors. ONOO - is able to induce nitration leading to the formation of 3-nytrotyrosine. This change has been widely studied, and although it is not only produced by ONOO-, but also by other reactive nitrogen species, it has been accepted like footprint of ONOO-. The excessive production of reactive nitrogen species is known as nitrosative stress that is able to induce structural damage leading to the loss of cell function. Furthermore, synthetic metalloporphyrins that metabolize ONOO- in a specific way are being used to determine if ONOO- is involved in different diseases, such as Alzheimer, Huntington, diabetes, hypertension, arthritis, colitis, cardiac and renal complications. Finally, these metalloporphyrins may be of potential therapeutic value in diseases related to ONOO- production.

El peroxinitrito (ONOO-) es una especie reactiva de nitrógeno formada por la reacción entre el óxido nítrico (NO•) y el anión superóxido (O2.- ). El NO' es sintetizado por la sintasa de óxido nítrico (NOS) y el O2•- se puede sintetizar de forma no enzimática, por la adición de un electrón al O2 o por medio de diversas enzimas como la NADPH oxidasa y la xantina oxidasa. El ONOO-es una especie oxidante capaz de modificar un gran número de biomoléculas entre las que se encuentran aminoácidos, proteínas, enzimas y cofactores de enzimas. El ONOO- puede inducir nitración de residuos de tirosina promoviendo la formación de 3-nitrotirosina (3-NT). Esta modificación ha sido muy estudiada y aunque no es producida exclusivamente por ONOO- sino también por otras especies reactivas de nitrógeno, se acepta actualmente como una evidencia de la formación de ONOO-. El aumento excesivo de este último, así como de otras especies reactivas de nitrógeno se conoce como estrés nitrosativo y puede causar daño estructural alterando la funcionalidad de las células. Por otra parte, se han desarrollado una serie de metaloporfirinas que descomponen específicamente al ONOO- y éstas han ayudado a determinar que el ONOO - es una especie implicada en enfermedades como Alzheimer, Huntington, diabetes, hipertensión, artritis, colitis y diversas complicaciones cardiacas y renales. Además, estas metaloporfirinas pueden ser de utilidad terapéutica en aquellas enfermedades asociadas a la producción de ONOO-.