Models of human psoriasis : Zebrafish the newly appointed player

Psoriasis is a human chronic, immune disease with severe cutaneous and systemic manifestations. Its prevalence, among the world population, highly varies with ethnicity and geography, but not sex from remarkable low levels in Asia to 2.3% in Spain, or an impressive 11.5% in Norway. The pathogenesis of psoriasis derives from complex genetic and environmental interactions, which creates aberrant crosstalk between keratinocytes and variated immune cell, resulting in open amplified inflammatory and pro-proliferative circuits. Both, innate and adaptive immune systems are known to be involved in the response at the cellular and humoral levels. Nevertheless, the exact molecular mechanisms are still under debate. Therefore, discovering useful therapeutic targets to stretch the molecular gaps in psoriasis pathogenesis and its associated comorbidities is still mandatory. So far, some mutagenic or pharmacological studies in vitro or using comparative vertebrate models have provided critical molecular insights and directed the human research. Although highly feasible in rodents, the versatile physiology, genetic similarity to humans and outstanding molecular toolbox available, suggest that elaborate forward genetic screenings are far easier to be conducted using the zebrafish model. Thus, in this review, we intend to briefly overview psoriasis and revise in a digested fashion the preclinical research models available, emphasizing the zebrafish as a powerful tool in the study of immune effectors on the same, and how it supports the discovering of new therapies that may help in controlling this widespread disease around the globe.publishedVersionUnit Licence Agreemen

A zebrafish model of Ifih1-driven Aicardi–Goutières syndrome reproduces the interferon signature and the exacerbated inflammation of patients

Type I interferonopathies are a heterogenic group of rare diseases associated with an increase in type I interferon (IFN). The main challenge for the study of Type I interferonopathies is the lack of a well-founded animal model to better characterize the phenotype as well as to perform fast and large drug screenings to offer the best treatment options. In this study, we report the development of a transgenic zebrafish model of Type I interferonopathy overexpressing ifih1 carrying the mutation p.Arg742His (Tg(ifih1_mut)), corresponding to the human mutation p.Arg779His. RNA sequence analysis from Tg(ifih1_mut) larvae revealed a systemic inflammation and IFN signature upon a suboptimal poly I:C induction compared with wild-type larvae, confirming the phenotype observed in patients suffering from Type I interferonopathies. More interestingly, the phenotype was manifested in the zebrafish inflammation and Type I IFN reporters nfkb:eGFP and isg15:eGFP, respectively, making this zebrafish model suitable for future high-throughput chemical screening (HTS). Using the unique advantages of the zebrafish model for gene editing, we have generated Tg(ifih1_mut) knocked down for mavs and ikbke, which completely abrogated the Poly I:C induction and activation of the GFP of the reporters. Finally, we used an FDA-approved drug, Baricitinib (Jak1/Jak2 inhibitor), which was able to reduce the inflammation and the ISG expression. Our results demonstrate the potential of this model to further understand AGS pathological mechanisms and to identify novel therapeutic drugs by HTS

Biopsia selectiva del ganglio centinela (BSGC) en melanoma. Comparación de dos métodos de procedimiento histológico

El melanoma es un tumor de estirpe melanocítica con un elevado potencial metastático y una incidencia en aumento. La técnica de la Biopsia Selectiva del Ganglio Centinela (BSGC) se acepta como la forma más específica, sensible y con menor morbilidad para realizar la estadificación patológica ganglionar. Objetivos:1) Analizar la capacidad de detección de un protocolo extenso, frente a un método simple de procesamiento del ganglio centinela comparando dos cohortes de pacientes; 2) buscar relación entre el resultado de la técnica de BSGC y otras variables con valor pronóstico establecido, tanto clínicas como histológicas; 3) realizar un estudio de supervivencia y de falsos negativos; 4) estudiar subgrupos de pacientes (melanomas ≥1 mm de Breslow, <1 mm de Breslow y melanomas en extremidades);y 5) comparar ambas técnicas desde el punto de vista económico. Metodología: Realizamos un estudio de cohortes con un diseño observacional analítico longitudinal. Se seleccionaron a los pacientes sometidos a la técnica desde el año 1998 hasta el 2010. La muestra a su vez se subdividió en dos series: la serie correspondiente a los años 1998-2004 y, la serie 2007-2010. En la primera de ellas se realizó un procesamiento simple (sección única de hematoxilina-eosina) mientras que en la segunda se realizó un estudio extenso (protocolo transhiliar bivalvo con secciones seriadas cada 250 µm y múltiples tinciones inmunohistoquímicas (HMB 45, Melan A y S100)). Conclusiones: El protocolo histopatológico extenso de análisis ganglionar ha demostrado mejorar la capacidad de detección de la técnica en nuestro medio. No hay diferencias en la tasa de falsos negativos, pero eliminando el factor de confusión correspondiente a los drenajes múltiples, la tasa disminuye a la mitad. El procesamiento por niveles al menos duplica el coste económico de la serie anterior. El porcentaje de pacientes sometidos a la técnica con melanomas delgados (índice de Breslow menor a 1 mm) es cada vez mayor (40%), aunque el rango de positividad es bajo (2%). La aparición de nuevas opciones de tratamiento en el melanoma metastásico obliga a optimizar la técnica con objeto de identificar el subgrupo de pacientes que podrían beneficiarse de estas nuevas terapias. Palabras clave: Melanoma, ganglio centinela. Melanoma is a melanocytic lineage tumor with high metastatic potential and increasing incidence. Sentinel lymph node biopsy (SLNB) is accepted as the most specific, sensitive and with less morbidity technique for pathologic nodal staging. Objectives: 1) To analyze the detection capability of an extensive protocol, versus a simple method of lymph node processing, comparing two cohorts of patients; 2) To seek a relationship between the outcome of the SLNB technique and other variables with established prognostic value, both clinical and histological; 3) To conduct a survival and false negatives study; 4) To study subgroups of patients (melanomas with Breslow thickness of 1 mm or more, <1 mm Breslow melanomas and extremity melanomas) and 5) To compare both lymph node processing methods from the economic point of view. Methods: Cohort study with a longitudinal observational analytic design was conducted. Patients undergoing SLNB in our institution from 1998 to 2010 were selected. The sample was divided into two cohorts, patients treated from 1998 to 2004 and those from 2007 to 2010. In the first subgroup, a simple method of processing was performed (single hematoxylin-eosin slide), while in the second, an extensive protocol (transhiliar bivalving 250µm serial sectioning with multiple immunohistochemical stains (HMB 45, Melan A and S100)) was carried out. Conclusions: Extensive histopathologic protocol for assessing sentinel node has shown an improved detection capability of the technique in our institution. No differences in false negatives rate were detected, but removing multiple drains confusion factor, this rate decreases by half. Extensive histopathologic protocol at least double the economic cost of the previous method. Percentage of patients undergoing SLNB technique with thin melanomas (less than 1 mm of Breslow thickness) is growing (40%), although positivity range is low (2%). New emerging treatment options in metastatic melanoma force to optimize the technique in order to identify the subgroup of patients who might benefit from these new therapies. Keywords: Melanoma, sentinel node

Models of human psoriasis : Zebrafish the newly appointed player

Psoriasis is a human chronic, immune disease with severe cutaneous and systemic manifestations. Its prevalence, among the world population, highly varies with ethnicity and geography, but not sex from remarkable low levels in Asia to 2.3% in Spain, or an impressive 11.5% in Norway. The pathogenesis of psoriasis derives from complex genetic and environmental interactions, which creates aberrant crosstalk between keratinocytes and variated immune cell, resulting in open amplified inflammatory and pro-proliferative circuits. Both, innate and adaptive immune systems are known to be involved in the response at the cellular and humoral levels. Nevertheless, the exact molecular mechanisms are still under debate. Therefore, discovering useful therapeutic targets to stretch the molecular gaps in psoriasis pathogenesis and its associated comorbidities is still mandatory. So far, some mutagenic or pharmacological studies in vitro or using comparative vertebrate models have provided critical molecular insights and directed the human research. Although highly feasible in rodents, the versatile physiology, genetic similarity to humans and outstanding molecular toolbox available, suggest that elaborate forward genetic screenings are far easier to be conducted using the zebrafish model. Thus, in this review, we intend to briefly overview psoriasis and revise in a digested fashion the preclinical research models available, emphasizing the zebrafish as a powerful tool in the study of immune effectors on the same, and how it supports the discovering of new therapies that may help in controlling this widespread disease around the globe

Image_4_A zebrafish model of Ifih1-driven Aicardi–Goutières syndrome reproduces the interferon signature and the exacerbated inflammation of patients.jpeg

Type I interferonopathies are a heterogenic group of rare diseases associated with an increase in type I interferon (IFN). The main challenge for the study of Type I interferonopathies is the lack of a well-founded animal model to better characterize the phenotype as well as to perform fast and large drug screenings to offer the best treatment options. In this study, we report the development of a transgenic zebrafish model of Type I interferonopathy overexpressing ifih1 carrying the mutation p.Arg742His (Tg(ifih1_mut)), corresponding to the human mutation p.Arg779His. RNA sequence analysis from Tg(ifih1_mut) larvae revealed a systemic inflammation and IFN signature upon a suboptimal poly I:C induction compared with wild-type larvae, confirming the phenotype observed in patients suffering from Type I interferonopathies. More interestingly, the phenotype was manifested in the zebrafish inflammation and Type I IFN reporters nfkb:eGFP and isg15:eGFP, respectively, making this zebrafish model suitable for future high-throughput chemical screening (HTS). Using the unique advantages of the zebrafish model for gene editing, we have generated Tg(ifih1_mut) knocked down for mavs and ikbke, which completely abrogated the Poly I:C induction and activation of the GFP of the reporters. Finally, we used an FDA-approved drug, Baricitinib (Jak1/Jak2 inhibitor), which was able to reduce the inflammation and the ISG expression. Our results demonstrate the potential of this model to further understand AGS pathological mechanisms and to identify novel therapeutic drugs by HTS.</p

Image_2_A zebrafish model of Ifih1-driven Aicardi–Goutières syndrome reproduces the interferon signature and the exacerbated inflammation of patients.jpeg

Type I interferonopathies are a heterogenic group of rare diseases associated with an increase in type I interferon (IFN). The main challenge for the study of Type I interferonopathies is the lack of a well-founded animal model to better characterize the phenotype as well as to perform fast and large drug screenings to offer the best treatment options. In this study, we report the development of a transgenic zebrafish model of Type I interferonopathy overexpressing ifih1 carrying the mutation p.Arg742His (Tg(ifih1_mut)), corresponding to the human mutation p.Arg779His. RNA sequence analysis from Tg(ifih1_mut) larvae revealed a systemic inflammation and IFN signature upon a suboptimal poly I:C induction compared with wild-type larvae, confirming the phenotype observed in patients suffering from Type I interferonopathies. More interestingly, the phenotype was manifested in the zebrafish inflammation and Type I IFN reporters nfkb:eGFP and isg15:eGFP, respectively, making this zebrafish model suitable for future high-throughput chemical screening (HTS). Using the unique advantages of the zebrafish model for gene editing, we have generated Tg(ifih1_mut) knocked down for mavs and ikbke, which completely abrogated the Poly I:C induction and activation of the GFP of the reporters. Finally, we used an FDA-approved drug, Baricitinib (Jak1/Jak2 inhibitor), which was able to reduce the inflammation and the ISG expression. Our results demonstrate the potential of this model to further understand AGS pathological mechanisms and to identify novel therapeutic drugs by HTS.</p