Introduktion: Psoriasis är en autoimmun hudsjukdom som orsakar fjällande, erytematösa plack på huden. Sjukdomen orsakas av genetiska och miljömässiga faktorer och den är kopplad till andra sjukdomar som psoriasisartrit. Immunceller i kroppen spelar en viktig roll i bildandet av psoriasis, så som T-celler och olika cytokiner, inklusive interleukin-23 (IL-23), IL-12, IL-6 och tyrosine kinase 2 (TYK2). Dessa inflammatoriska faktorer leder till överdriven tillväxt av keratinocyter i huden och bidrar till bildandet av psoriasis. Plackpsoriasis är den vanligaste typen av psoriasis där den uppträder symmetriskt i kroppen. Den kan orsaka torra fjäll och smärtsamma sprickor vilket försämrar patientens livskvalitet. Forskning pågår fortfarande i strävan efter nya läkemedel medbättre effekt och färre biverkningar. Det finns olika orala behandlingar som riktar sig mot immunmolekyler i kroppen och hämmar deras verkan för att lindra symptomen på plackpsoriasis. Apremilast, en oral fosfodiesteras 4 (PDE4) hämmare, har visat en god terapeutisk effekt och säkerhet medan deucravacitinib är en ny oral selektiv TYK2-hämmare som har en god effekt och bra säkerhetsprofil. Syfte: Syftet var att hitta och analysera kliniska studier för att ta reda på om oral behandling med deucravacitinib har bättre effekt och säkerhet än apremilast vid behandling av patienter med medelsvår till svår plackpsoriasis. Metod: Databasen PubMed användes för att hitta fem vetenskapliga artiklar som undersökte effekt och säkerhet på de två läkemedlen i fråga. Studierna analyserades och utifrån analyserna drogs slutaster som besvarar syftet med arbetet. Resultat: De två första studierna hade till syfte att jämföra deucravacitinib med apremilast genom en så kallad ”head to head”. De visade en signifikant överlägsenhet av deucravacitinib över apremilast för att uppnå 75 % förbättring av Psoriasis Area and Severity Index (PASI 75) och Static Physician's Global Assessment score of 0 (clear) or 1 (almost clear) (sPGA 0/1) samt en bra säkerhetsprofil. Medan den tredje och fjärde studien visade att apremilast hade en överlägsen terapeutisk effekt jämfört med placebo. Patienterna nådde PASI 75 och sPGA-värden signifikant med en bra säkerhetsprofil. När det gäller den femte studien så jämförde den deucravacitinib med placebo. Dess resultat överensstämde med resultaten av de två första studierna. Diskussion: De fem artiklarna som analyserades var randomiserade kliniska studier på patienter med plackpsoriasis vilket gav tillförlitliga slutsatser. Det fanns felkällor så som det lilla antalet deltagare i den tredje och femte studien och bristen på tillräcklig etnisk mångfald. Vid jämförelse av PASI-värdena för de fem studierna så hade deucravacitinib bättre terapeutiska värden än apremilast. När det gäller säkerhetsprofilen så minskade kardiovaskulära biverkningar signifikant vid behandling med deucravacitinib. Slutsats: Deucravacitinib har en bättre effekt än apremilast samt bättre säkerhetsprofil vid behandling av patienter med medelsvår till svår plackpsoriasis

Psoriasis ist eine komplexe entzündliche Erkrankung der Haut. Charakteristisch ist eine dichte Infiltration von T-Lymphozyten und eine Hyperproliferation der Epithelschicht. Heutzutage belegen die Ergebnisse vieler experimteller Studien, daß Psoriasis eine T-Zell-induzierte Erkrankung ist. Die Spezifität der T-Zell-stimulierenden Antigene ist noch unbekannt. Voraussetzung für die Charakterisierung psoriatischer T-Zellen ist die Isolation von T-Zell-Klonen aus psoriatischen Plaques, deren Restimulation in vitro qualitativ und quantitativ erfaßbar ist. Hierfür haben wir einen hochsensiblen gamma-Interferon Elispot-Assay etabiert, der die Aktivität der T-Zellen aus Hautplaques erfaßt. Zudem zeigen wir, daß man aktivierte T-Zell-Klone mittels CD25-Markierung isolieren und anschließend klonieren kann. Unsere Ergebnisse können als eine Grundlage für weitere Versuche dienen, die die Spezifität von T-Zell-Klonen aus psoriatischen Plaques charakterisieren sollen. / Psoriasis is a complex inflammatory disease of the skin characterized by a dense infiltration of T-lymphocytes and a hyperproliferation of the epithelial layer. A host of experimental and clinical data suggest that psoriasis is a T cell mediated disorder. The nature of T-cell-stimulating antigens is still unknown. One way to identify putative antigen(s) is the definition of T-cell-receptor specifities using randomized combinatorial peptide libraries. This requires the isolation and expansion of T cell clones from psoriatic plaques in vitro. Therefore we established a gamma-interferon Elispot-assay which allows quantification of the frequency of activated plaque-derived T cells in vitro. In addition, we show that activated T cell clones can be sorted via CD25 and cloned. The expanded clones can also be restimulated by autologous cells. Our results should be useful in the design of experiments aiming at a systematic analysis of the specifity of T cell clones present in psoriatic plaques.

No description available.

"Gar Demia", es un documental que aborda el viaje de un paciente recién diagnósticado con la enfermedad de la Psoriasis, enfermedad inflamatoria y crónica de la piel, de origen autoinmune; en él se muestra desde mi perspectiva cómo voy encontrando personas en el camino que cuentan con el mismo diagnóstico, así mismo, se van presentando sus testimonios y dificultades de vivir con la enfermedad por el tiempo que lo lleven haciendo. / Trabajo de suficiencia profesional

La famille des kinases Src, dont Lyn fait partie, joue un rôle clé dans le contrôle de nombreux processus biologiques. Lyn a une fonction bien établie dans les cellules hématopoïétiques et est notamment impliqué dans le maintien de différentes leucémies et son expression protéique est altérée dans les tumeurs solides. Plusieurs études ont mis en évidence qu’elle avait un rôle anti-apoptotique. Lyn peut être clivée par les caspases en donnant une protéine tronquée cytosolique. Nous avons ainsi montré que Lyn cytosolique (cLyn) régulait Bim, un membre pro-apoptotique de la famille Bcl-2, en le phosphorylant sur les tyrosines 92 et 161 en inhibant la fonction pro-apoptotique de Bim, en augmentant son interaction avec Bcl-XL, limitant ainsi la perméabilisation de la membrane externe mitochondriale et l’apoptose. Lyn possède également un rôle pro-inflammatoire. Nous avions préalablement montré que la surexpression de cLyn, chez la souris, conduit à un syndrome inflammatoire de la peau, ressemblant au psoriasis. Sur la base de ce résultat, nous avons voulu savoir si Lyn jouait un rôle dans cette maladie chronique de la peau. L’analyse de l’expression de Lyn chez des patients souffrant de psoriasis a montré que Lyn était surexprimée dans la peau lésionnelle par rapport à la peau non lésionnelle ou saine, résultats confirmés dans deux modèles de psoriasis chez la souris. De façon intéressante, nous avons montré que l’augmentation de l’expression de Lyn se situe à la fois dans le derme et dans l’épiderme chez l’homme et chez la souris, indiquant que le recrutement de cellules immunitaires dans la peau lésionnelle mais aussi la modulation de Lyn dans les kératinocytes sont impliqués. Par ailleurs, une augmentation de l’expression de Lyn a été observée dans les kératinocytes humains stimulés par le TNF-α et l'IL-17A. Afin de déterminer le rôle de Lyn dans cette maladie cutanée nous l’avons induit chez des souris déficientes pour Lyn. Une réduction significative du phénotype cutanée a été observée dans les souris LynKO, identifiant Lyn comme un nouvel acteur dans la pathogénie du psoriasis. De plus, nos résultats ont établi que l’expression de Lyn dans les kératinocytes semblait suffisante pour le maintien du phénotype psoriasique, indiquant un nouveau rôle de Lyn dans les kératinocytes. Au cours de ce travail, nous avions observé que les caspases inflammatoires étaient activées dans la peau lésionnelle de patients atteints du psoriasis. Les caspases inflammatoires, suite à leur activation, vont cliver l’IL-1β et l’IL-18, ce qui conduit à leur maturation. Nous avons alors voulu savoir si les caspases participaient au développement du psoriasis. Nous avons pu montrer que lorsque nous induisions du psoriasis chez des souris, l’invalidation des caspases inflammatoires ou son inhibition pharmacologique réduisait de façon significative le développement de la maladie. Bien que les cellules immunitaires et les kératinocytes soient capables de secréter de l’IL-1β via l’activation de l’inflammasome, nos données ont établi que seule l’activation des caspases inflammatoires dans le système immunitaire semblait nécessaire pour une réponse inflammatoire complète. En résumé, l’ensemble de mon travail de thèse a permis de montrer un mécanisme moléculaire par lequel la kinase Lyn régule négativement la voie apoptotique mitochondriale, ce qui peut contribuer à la transformation et/ou la résistance des cellules cancéreuses. D’autre part, nos résultats montrent que Lyn pourrait être un régulateur important du psoriasis, et notre étude indique que les caspases inflammatoires activées dans les cellules immunitaires sont impliquées dans la pathogenèse du psoriasis. A ce jour, bien que plusieurs traitements aient été développés pour le psoriasis, la maladie reste non résolue, donc le développement de cibles thérapeutiques contre Lyn et les caspases inflammatoires pourraient être intéressant pour le traitement de la maladie. / The Src family kinase, of which Lyn is one member, plays a key role in controlling many biological processes. Lyn has a well-established function in hematopoietic cells, presenting an important role in the regulation of hematopoietic abnormalities. In fact, Lyn plays a key role in maintaining several kind of leukemia, and furthermore it expression is altered in solid tumors. Different studies have shown that Lyn has an anti-apoptotic role. Lyn can be cleaved by caspases, cysteine proteases involved in apoptosis and inflammation, giving a new protein with a cytosolic location, different from the WT and membrane-anchored form. We have shown that the cytosolic form of Lyn (cLyn) regulated Bim, a pro-apoptotic member of the Bcl-2 family, involved in the control of mitochondrial apoptosis. We have identified that Bim is phosphorylated on tyrosine 92 and 161 by Lyn, resulting in an inhibition of its pro-apoptotic function, increasing its interaction with anti-apoptotic members such as Bcl-XL, thus limiting the permeabilization of mitochondrial outer membrane and impairing cell apoptosis. Lyn also has a pro-inflammatory role. We have previously shown that overexpression of the caspase-cleaved form of Lyn, in mice, leads to an inflammatory skin syndrome, resembling human psoriasis. Based on this result, we wanted to know if Lyn played a role in this chronic skin disease. Analysis of Lyn's expression in psoriasis patients showed that Lyn was overexpressed in lesional skin compared to non-lesional or healthy skin, which was subsequently confirmed in two mouse models of psoriasis disease. Interestingly, we have shown that the increase in Lyn expression is in both the dermis and the epidermis in humans and in mice, indicating that recruitment of immune cells into lesional skin but also the modulation of Lyn in keratinocytes are involved. To determine the role of Lyn in this skin disease we induced a psoriasis-like phenotype in Lyn deficient mice. A significant reduction in cutaneous phenotype was observed in LynKO mice compared to WT mice, identifying Lyn as a new player in the pathogenesis of psoriasis. In addition, our results established that Lyn expression in keratinocytes seemed crucial and sufficient for the maintenance of the psoriasis phenotype, indicating a new role of Lyn in the regulation of keratinocytes. During this work, we observed that inflammatory caspases were activated in lesional skin from psoriasis patients. Inflammatory caspases, following their activation within the inflammasome, will cleave IL-1β and IL-18, leading to their maturation. We then wanted to know if inflammatory caspases participated in the development of psoriasis. We were able to show that when we induced a psoriasis-like disease in mice, the invalidation of inflammatory caspases or its pharmacological inhibition significantly reduced the development of the disease compared to WT mice. Although immune cells and keratinocytes were able to secrete IL-1β via activation of the inflammasome, our data established that only activation of inflammatory caspases in the immune system seemed necessary for a complete inflammatory response. In summary, my thesis shows a molecular mechanism by which Lyn tyrosine kinase negatively regulates the mitochondrial apoptotic pathway, which may contribute to the transformation and/or chemotherapeutic resistance of cancer cells. On the other hand, our results show that Lyn could be an important regulator of psoriasis and our study indicates that inflammatory caspases activated in immune cells are involved in the pathogenesis of psoriasis. To date, although several treatments have been developed for psoriasis, the disease remains unresolved, so the development of therapeutic targets against Lyn and inflammatory caspases could be of interest for the treatment of the disease.

Background: About 2% of the German population are affected by psoriasis. A growing number of cost-intensive systemic treatments are available. Surveys have shown high proportions of patients with moderate to severe psoriasis are not adequately treated despite a high disease burden. Digital therapy recommendation systems (TRS) may help implement guideline-based treatment. However, little is known about the acceptance of such clinical decision support systems (CDSSs). Therefore, the aim of the study was to access the acceptance of a prototypical TRS demonstrator. - Methods: Three scenarios (potential test patients with psoriasis but different sociodemographic and clinical characteristics, previous treatments, desire to have children, and multiple comorbidities) were designed in the demonstrator. The TRS demonstrator and test patients were presented to a random sample of 76 dermatologists attending a national dermatology conference in a cross-sectional face-to-face survey with case vignettes. The dermatologist were asked to rate the demonstrator by system usability scale (SUS), whether they would use it for certain patients populations and barriers of usage. Reasons for potential usage of the TRS demonstrator were tested via a Poisson regression with robust standard errors. Results: Acceptance of the TRS was highest for patients eligible for systemic therapy (82%). 50% of participants accepted the system for patients with additional comorbidities and 43% for patients with special subtypes of psoriasis. Dermatologists in the outpatient sector or with many patients per week were less willing to use the TRS for patients with special psoriasis-subtypes. Dermatologists rated the demonstrator as acceptable with an mean SUS of 76.8. Participants whose SUS was 10 points above average were 27% more likely to use TRS for special psoriasissubtypes. The main barrier in using the TRS was time demand (47.4%). Participants who perceived time as an obstacle were 22.3% less willing to use TRS with systemic therapy patients. 27.6% of physicians stated that they did not understand exactly how the recommendation was generated by the TRS, with no effect on the preparedness to use the system. - Conclusion: The considerably high acceptance and the preparedness to use the psoriasis CDSS suggests that a TRS appears to be implementable in routine healthcare and may improve clinical care. Main barrier is the additional time demand posed on dermatologists in a busy clinical setting. Therefore, it will be a major challenge to identify a limited set of variables that still allows a valid recommendation with precise prediction of the patient-individual benefits and harms.

Introdução: A terapêutica da psoríase foi modificada pela introdução dos imunobiológicos, que permitem melhor controle da doença e melhor qualidade de vida aos pacientes, mas promovem aumento do risco de tuberculose latente, exigindo diagnóstico antecedendo seu início. Objetivo: Avaliar o desempenho do teste T-SPOT.TB no diagnóstico de infecção tuberculosa latente em pacientes com psoríase. Métodos: Em estudo experimental, prospectivo, analítico, com comparação de grupos,de prevenção primária, para validade de teste diagnóstico, 33 pacientes com psoríase (grupo psoríase) e 30 pacientes com outras doenças dermatológicas (grupo base), atendidos nos Ambulatório de Dermatologia Geral ou de Psoríase do Centro de Estudos Dermatológicos do Recife, da Santa Casa de Misericórdia, entre fevereiro e novembro de 2009, foram submetidos aos testes do PPD e T-SPOT.TB. Para ambos os grupos, admitiu-se inclusão com idade mínima de 18 anos e critérios de exclusão doenças ou condições fisiológicas que comprometessem a competência imunológica, exceto psoríase, para o grupo psoríase. Adotou-se a técnica de Mantoux para o teste do PPD e uma variante simplificada da técnica Enzyme-Linked Immunospot para a determinação de células T efetoras, secretoras de IFN-g em resposta à estimulação pelos antígenos específicos do M. tuberculosis para o teste T-SPOT.TB. As variáveis dependentes foram os resultados do teste T-SPOT.TB contra antígenos ESAT-6, CFP-10, e os resultados do teste do PPD, considerando enduração de 0-4 mm: não reator; 5-9 mm: reator fraco; ≥ 10 mm: reator forte. As variáveis independentes foram: idade, sexo, cor da pele, tempo de evolução da psoríase, ocupação, história de contato intradomiciliar e renda, alcoolismo e gravidade da doença. Foram submetidos a teste Qui quadrado ou exato de Fisher, em nível de significância de 0, 05, assim como ao teste de Mantel-Haenszel, três modelos comparando o teste T-SPOT.TB com teste do PPD, contato intradomiciliar e associação teste do PPD e contato intradomiciliar. A pesquisa foi aprovada pelos Comitês de Ética da Universidade Federal de Pernambuco e Universidade de São Paulo. Resultados: O grupo psoríase diferiu do grupo base quanto a razão de sexo com predomino do masculino (razão=0,7:1; p=0,047); maior idade média 42,1±1,9 anos (contra 34,1±1,4 anos no grupo base, p=0,023); fototipos I e II (p=0,020); menor nível de instrução e renda média mensal e contato intradomiciliar com tuberculose menos freqüente (p=0,001). Os grupos também diferiram quanto à positividade do teste do PPD (maior no grupo base; p=0,001). O teste T-SPOT.TB apresentou sensibilidade e especificidade de 9,1% e 95,5%, no modelo 1, 27,3% e 60%, no modelo 2, e valores de 60% e 53,3%, respectivamente no modelo 3. Foi no modelo 1 do grupo psoríase que o teste TSPOT. TB mostrou a maior concordância e o maior valor de Odds Ratio ponderado pelo teste de Mantel-Haenszel, tendo esses dois parâmetros significância estatística, quando comparados aos outros dois modelos. Conclusões: O teste T-SPOT.TB apresentou maior capacidade de diagnosticar casos negativos para tuberculose latente, constituindo-se numa opção para triagem de pacientes na instituição de terapêutica com imunobiológicos. / Introduction: The therapy for psoriasis was modified by the introduction of immunebiological products that allow better disease control and better quality of life for patients, but promotes increased risk forf latent tuberculosis, requiring diagnosis shortly before its establishment. Purpose: To assess the performance of T-SPOT.TB test for the diagnosis of latent tuberculosis infection in patients with psoriasis. Methods: Within a experimental, prospective, analytic, clinical assay type study, with comparison of groups, to validate a diagnostic test, 33 patients with psoriasis (psoriasis group) and 30 patients with other dermatological diseases (basis group), attempted at General Dermatology and Psoriasis Out-patients Departments of Recife\'s Dermatological Studies Center of Santa Casa de Misericórdia, from February to November 2009, were submitted to PPD and TSPOT. TB tests. For both groups, we admitted 18 years as minimal age for inclusion. The exclusion criteria included disease ou physiological conditions that compromised immunological competence, except psoriasis to psoriasis group. We used Mantoux technique for PPD test and a simplified variant of Enzyme-Linked Immunospot technique to determine effector T cells, secretors of IFN-g in response to M. tuberculosis specific antigens, to T-SPOT.TB test. Dependent variables were the results of T-SPOT.TB test against ESAT-6 and CPF-10 antigens, and the results to PPD test, considering enduration of 0-4 mm as non reactor; 5-10 mm weak reactor and ≥ 10 mm, strong reactor. Independent variables were age, sex, skin color, psoriasis evolution time, occupation, history of intradomiciliar contact and income, alcoolism and disease grade. Three models, comparing T-SPOT.TB test to PPD test, intradomiciliar contact and both, were submitted to Qui Squared test or Exact Fisher Test, at significance level of 0.05, as well as to Mantel- Haenszel test. The research has been approved by Ethics Committee of Universidade Federal de Pernambuco e Universidade de São Paulo. Results: Psoriasis group differed from base group on sex ratio with predominance of male gender (rate=0.7:1; p=0,047), major mean age (42,1 ± 1.9 years against 34,1 ± 1.4 years in basic group, p = 0,023) phototypes I and II (p = 0,020); lower scholarship, income and less frequent intradomiciliar contact with tuberculosis (p = 0,001). The groups also differed on the positivity of PPD test (greater in base group; p = 0,001). T-SPOT.TB test had sensibility and specificity of 9,1% and 95.5%, in model 1; 27,3% and 60%, in model 2, and values of 60% and 53,3% respectively in model 3. Model 1 showed greater concordance and highest value of Odds Ratio test weighted by Mantel-Haenszel test, having these two parameters statistical significance when compared to the other two models. Conclusions: T-SPOT.TB test had great ability to diagnose negative cases for latent tuberculosis, and constitutes an option for screening patients to immunobiological therapy administration.

A psoríase é uma doença de pele inflamatória crônica, que afeta cerca de 2-4% da população mundial. Se desenvolve ao longo do tempo, principalmente no final da adolescência ou início da idade adulta e depende de uma complexa interação entre fatores genéticos e ambientais. Dados experimentais demostram que a dermatite induzida por imiquimode (IMQ) em camundongos assemelha-se estreitamente às lesões de psoríase humana, tanto nas características fenotípicas e histológicas como no desenvolvimento das lesões na epiderme. O estudo avaliou os efeitos anti-inflamatórios do óleo de semente de maracujá (Passiflora edulis) no tratamento da psoríase, utilizando a análise histológica e imunológica da epiderme. O experimento foi realizado com 36 camundongos Balb/c, os quais foram submetidos à indução da psoríase por imiquimode, por 10 dias consecutivos. O tratamento foi realizado com óleo de semente de maracujá in natura 100%, pomada LECIGEL® 2%, pomada associação de óleo de semente de maracujá 20% e LECIGEL® 2%, por 15 dias. Tanto o óleo da semente do maracujá quanto a associação do mesmo ao LECIGEL® diminuíram o quadro inflamatório induzido por imiquimode nas orelhas tratadas. Através das análises imuno-histoquímicas realizadas na epiderme (PCNA, IL-6, VEGF, CD34), observou-se um aumento na formação de corpos apoptóticos, diminuição a hiperplasia epitelial e redução do infiltrado inflamatório. Os resultados deste experimento demonstraram que o óleo da semente do maracujá desempenha um efeito anti-inflamatório no tratamento da psoríase induzida por imiquimode. / Psoriasis is a chronic inflammatory skin disease that affects about 2-4% of the world\'s population. It develops over time, especially in late adolescence or early adulthood and depends on a complex interaction between genetic and environmental factors. Experimental data show that imiquimode-induced dermatitis (IMQ) in mice closely resembles human psoriasis lesions, both in phenotypic and histological characteristics and in the development of lesions in the epidermis. The study evaluated the anti-inflammatory effects of passion fruit (Passiflora edulis) oil in the treatment of psoriasis, using the histological and immunological analysis of the epidermis. The experiment was performed with 36 Balb / c mice, which were submitted to psoriasis induction by imiquimode, for 10 consecutive days. The treatment was carried out with 100% fresh passion fruit seed oil, LECIGEL ® 2% ointment, 20% passion fruit seed oil ointment and LECIGEL ® 2% for 15 days. Both passionflower seed oil and its association with LECIGEL ® decreased the imiquimod-induced inflammation in the treated ears. Through the immunohistochemical analyzes performed on the epidermis (PCNA, IL-6, VEGF, CD34), an increase in the formation of apoptotic bodies, decrease in epithelial hyperplasia and reduction of inflammatory infiltrate was observed. The results of this experiment suggest that passion fruit seed oil has an anti-inflammatory effect in the treatment of imiquimode-induced psoriasis.

A psoríase é uma doença inflamatória crônica, de alta incidência mundial, caracterizada por lesões de pele e prurido. Achados prévios do grupo mostraram que a administração i.p. do doador lento de sulfeto de hidrogênio (H2S), GYY4137, inibiu significativamente a inflamação cutânea e coceira em animais com psoríase. Assim, neste estudo avaliou-se o efeito terapêutico de uma nanodispersão tópica contendo GYY4137 sobre a psoríase induzida por imiquimode em camundongos e, comparou-se farmacologicamente o efeito do GYY4137 versus dexametasona. Animais controle ou psoríase foram tratados (1 e 2x/dia) com a nanodispersão (65 mg) contendo GYY4137, dexametasona ou apenas veículo. A aplicação tópica da nanodispersão com o GYY4137 (4%) 2x/dia, foi mais efetiva e reduziu de forma significativa o rubor, espessura, células sanguíneas totais, MPO e níveis de IL-6 e IL-1β. Os efeitos farmacológicos promovidos pelo H2S foram semelhantes aos da dexametasona, porém, a nanodispersão contendo GYY4137 demonstrou efeitos sistêmicos menos pronunciados quando comparada ao glicocorticóide. / Psoriasis is a chronic inflammatory disease, with high incidence worldwide and, characterized by skin lesions and intense itching. Previous findings of this group showed that systemic administration of the slow donor release of hydrogen sulfide (H2S), GYY4137, significantly inhibited skin inflammation and itching in mice with psoriasis. Thus, this study evaluated the therapeutic effect of a topical nanodispersion containing GYY4137 on the Imiquimod-induced psoriasis mice model and compared pharmacologically the effect of GYY4137 versus dexamethasone. Control or psoriasis animals were treated (1 and 2x/day) with nanodispersion (65 mg) containing GYY4137, dexamethasone, or just vehicle. Topical application of the nanodispersion with GYY4137 (4%) 2x/day was more effective and significantly reduced redness, thickness, total blood cells, MPO, and IL-6 and IL-1β levels. The pharmacological effects caused by H2S were similar to those of dexamethasone, however, the nanodispersion containing GYY4137 demonstrated less systemic effects when compared to glucocorticoid.

Made available in DSpace on 2017-07-21T14:13:10Z (GMT). No. of bitstreams: 1 Stefanie Nolte.pdf: 1509773 bytes, checksum: dbef289d8b9a1e611bef15b9a6d2f33c (MD5) Previous issue date: 2013-02-21 / Introduction: Psoriasis is a skin inflammatory disease characterized by keratinocytes hyperproliferation and their incomplete differentiation in the epidermis. Treatment aims to reduce the psoriatic plaques formation; however, many therapeutic regimens do not produce satisfactory results. Searching for new alternatives, this study evaluated the possible effect of the TTHL compound, isolated from the ethanolic extract of Combretum leprosum, on HaCaT proliferation.Methods: The cellular viability was assessed 24 hours after the treatment with different concentrations of TTHL through MTT and neutral red methods. To evaluate the TTHL anti-proliferative activity, the cells were treated with different concentrations of TTHL, in alternate days (96 hours) and analyzed through MTT and Cyquant methods. The cell cycle was evaluated by flow citometry. The possible toxicity by the topical application of the TTHL (0.3 mg/ear) was assessed in vivo, through skin atrophy, by measuring ear thickness of animals and histology.Results: The MTT assay showed, after 24 hours, that TTHL presents cytotoxic activity in HaCaT cells, at the concentrations of 5, 7, 9 and 10 μM, decreasing, respectively, 53.54, 89.53, 89.69 and 90.30 ± 5.84% the cellular viability compared to the control group. The neutral red assay, in the same concentrations, decreased 39.83%, 48.67%, 47.78% and 50.44 ± 4.42%, respectively. In the cellular proliferation assay, the 5, 7 and 10 μM concentrations decreased 24.27%, 59.25% and 82.30% ± 5.96% the cells number, as showed in the MTT method, and 30.30%, 59.59% e 90.90% ± 6.03% as showed in the Cyquant method. The cell cycle assay showed that, at the concentrations of 5, 7 and 10 μM, the non-viable cells number was higher and statistically significant when compared to the control group. Through the skin atrophy assay was possible to conclude that TTHL does not cause atrophy.Conclusion: TTHL is capable of reducing cell viability. These data suggest that TTHL might be a possible tool for the treatment of hyperproliferative diseases, among them, psoriasis. However, additional studies are needed to verify the action mechanism and triterpene safety. / Introdução: A psoríase é uma doença inflamatória cutânea caracterizada pela hiperproliferação e diferenciação incompleta de queratinócitos na epiderme. O tratamento tem como objetivo reduzir a formação de placas psoriáticas, porém muitos regimes terapêuticos não produzem resultados satisfatórios. Buscando alternativas, este trabalho avaliou o possível efeito do composto TTHL, isolado do extrato etanólico de Combretum leprosum, sobre a proliferação de HaCaT. Métodos: A viabilidade celular foi avaliada 24 horas após o tratamento com diferentes concentrações de TTHL, através do método de MTT e vermelho neutro. Para avaliar a atividade antiproliferativa, as células foram tratadas com diferentes concentrações de TTHL, em dias alternados e analisadas através do método de MTT e Cyquant. O ciclo celular foi avaliado por citometria de fluxo. A possível toxicidade pela aplicação tópica do TTHL foi avaliada in vivo, pelo ensaio de atrofia cutânea, através da medida da espessura da orelha dos animais e histologia. Resultados: No ensaio de MTT, após 24 horas, o TTHL, apresentou atividade citotóxica nas células HaCaT, nas concentrações de 5, 7, 9 e 10 μM, diminuindo, respectivamente em 53,54, 89,53, 89,69 e 90,30 ± 5,84% a viabilidade celular quando comparado ao grupo controle. No ensaio de vermelho neutro, essas mesmas concentrações diminuíram 39,83%, 48,67%, 47,78% e 50,44 ± 4,42%, respectivamente. No ensaio de proliferação celular, nas concentrações de 5, 7 e 10 μM, observou-se diminuição de 24,27%, 59,25% e 82,30% ± 5,96% no número de células, conforme o método de MTT e 30,30%, 59,59% e 90,90% ± 6,03% conforme o método de Cyquant. No ensaio de ciclo celular observou-se que nas concentrações de 5, 7 e 10 μM o número de células não viáveis foi maior e estatisticamente significante quando comparado com o grupo controle. Através do ensaio de atrofia cutânea foi possível concluir que o TTHL não causa atrofia. Conclusão: O TTHL é capaz de diminuir a viabilidade celular. Esses dados sugerem que o TTHL possa ser uma possível ferramenta para o tratamento de doenças hiperproliferativas, dentre elas, a psoríase. Entretanto, estudos adicionais são necessários para verificar o mecanismo de ação e segurança do triterpeno.