Psoriasis ungueal: tratamiento con ungüento hidrófilo de tazaroteno al 0.1 por ciento / Nail Psoriasis: Treatment With Tazarotene 0.1 percent Hydrophilic Ointment

Introducción: La afectación ungueal de la psoriasis es una presentación frecuente que interfiere de manera significativa en la calidad de vida de los pacientes. Su presentación clínica va a depender del área ungueal afecta: lecho o matriz. Un 50% de los pacientes refiere dolor asociado. En este estudio evaluamos la eficacia y seguridad del tazaroteno 0,1% en ungüento hidrófilo. Material y métodos: Estudio abierto y observacional de 6 pacientes diagnosticados de psoriasis ungueal. Se aplicó ungüento de tazaroteno 0,1% (fórmula magistral) en oclusión nocturna, en su domicilio durante 6 meses, sin otro tratamiento tópico o sistémico. Se determinó el Nail Psoriasis Severity Index (NAPSI) y se evaluaron la hiperqueratosis subungueal, onicólisis, hemorragias en astilla, manchas de aceite y piquiteado ungueal, en la visita basal, a los 3 y 6 meses. Resultados: Se observó una mejoría estadísticamente significativa en todos los pacientes: NAPSI basal, media ± DE 14,3± 6,3; IC 95% 11,74-16,92; mediana 15; NAPSI a los 6 meses: media ± DE 2,3 ±1,21; IC 95% 1,84-2,83; mediana 2,5; p=0,007. El porcentaje de mejoría fue del 87,9% al final del tratamiento. No se registraron efectos adversos. Conclusión: Nuestro estudio muestra un potencial terapéutico del ungüento de tazaroteno en la psoriasis ungueal (AU)

Introduction: Nail involvement is common in psoriasis and has a considerable impact on patient quality of life. Its clinical presentation depends on which part of the nail is affected: the bed or the matrix. Fifty percent of patients report associated pain. In this study, we analyzed the safety and effectiveness of tazarotene 0.1% in a hydrophilic ointment in the treatment of nail psoriasis. Material and methods: We performed an open observational study of 6 patients diagnosed with nail psoriasis. The patients applied a compounded preparation of tazarotene 0.1% ointment under occlusion every night for 6 months in their homes. They were not receiving any other topical or systemic treatments. Nail psoriasis severity (assessed using the Nail Psoriasis Severity Index [NAPSI]), subungual hyperkeratosis, onycholysis, splinter hemorrhages, oil stains, and nail pitting were evaluated at baseline and at 3 and 6 months. Results: A statistically significant improvement between baseline and 6 months was observed in all patients: the mean (SD) NAPSI went from 14.3 (6.3; 95% CI, 11.74-16.92) to 2.3 (1.21; 95% CI, 1.84-2.3) while the median went from 15 to 2.5 (P = 0.007). The percentage improvement at the end of treatment was 87.9%. No adverse effects were observed. Conclusion: Our study shows the therapeutic potential of tazarotene ointment in nail psoriasis (AU)

Nail psoriasis: treatment with tazarotene 0.1% hydrophilic ointment.

INTRODUCTION: Nail involvement is common in psoriasis and has a considerable impact on patient quality of life. Its clinical presentation depends on which part of the nail is affected: the bed or the matrix. Fifty percent of patients report associated pain. In this study, we analyzed the safety and effectiveness of tazarotene 0.1% in a hydrophilic ointment in the treatment of nail psoriasis. MATERIAL AND METHODS: We performed an open observational study of 6 patients diagnosed with nail psoriasis. The patients applied a compounded preparation of tazarotene 0.1% ointment under occlusion every night for 6 months in their homes. They were not receiving any other topical or systemic treatments. Nail psoriasis severity (assessed using the Nail Psoriasis Severity Index [NAPSI]), subungual hyperkeratosis, onycholysis, splinter hemorrhages, oil stains, and nail pitting were evaluated at baseline and at 3 and 6 months. RESULTS: A statistically significant improvement between baseline and 6 months was observed in all patients: the mean (SD) NAPSI went from 14.3 (6.3; 95% CI, 11.74-16.92) to 2.3 (1.21; 95% CI, 1.84-2.3) while the median went from 15 to 2.5 (P = .007). The percentage improvement at the end of treatment was 87.9%. No adverse effects were observed. CONCLUSION: Our study shows the therapeutic potential of tazarotene ointment in nail psoriasis.

Interfering with multimerization of netrin-1 receptors triggers tumor cell death.

Netrin-1 was recently proposed to control tumorigenesis by inhibiting apoptosis induced by the dependence receptors DCC (Deleted in colorectal cancer) and UNC5H. Although the loss of these dependence receptors' expression has been described as a selective advantage for tumor growth and progression in numerous cancers, recent observations have shown that some tumors may use an alternative strategy to block dependence receptor-induced programmed cell death: the autocrine expression of netrin-1. This alternative strategy has been observed in a large fraction of aggressive breast cancers, neuroblastoma, pancreatic adenocarcinoma, and lung cancer. This observation is of potential interest regarding future targeted therapy, as in such cases interfering with the ability of netrin-1 to inhibit DCC or UNC5H-induced cell death is associated with apoptosis of netrin-1-expressing tumor cells in vitro, and with inhibition of tumor growth or metastasis in different animal tumor models. The understanding of the mechanism by which netrin-1 inhibits cell death is therefore of interest. Here, we show that netrin-1 triggers the multimerization of both DCC and UNC5H2 receptors, and that multimerization of the intracellular domain of DCC and UNC5H2 is the critical step to inhibit the proapoptotic effects of both of these receptors. Taking advantage of this property, we utilized a recombinant specific domain of DCC that (i) interacts with netrin-1 and (ii) inhibits netrin-1-induced multimerization, to trigger apoptosis in netrin-dependent tumor cells.

Netrin-1 interacts with amyloid precursor protein and regulates amyloid-beta production.

The beta-amyloid precursor protein (APP) is an orphan transmembrane receptor whose physiological role is largely unknown. APP is cleaved by proteases generating amyloid-beta (Abeta) peptide, the main component of the amyloid plaques that are associated with Alzheimer's disease. Here, we show that APP binds netrin-1, a multifunctional guidance and trophic factor. Netrin-1 binding modulates APP signaling triggering APP intracellular domain (AICD)-dependent gene transcription. Furthermore, netrin-1 binding suppresses Abeta peptide production in brain slices from Alzheimer model transgenic mice. In this mouse model, decreased netrin-1 expression is associated with increased Abeta concentration, thus supporting netrin-1 as a key regulator of Abeta production. Finally, we show that netrin-1 brain administration in Alzheimer model transgenic mice may be associated with an amelioration of the Alzheimer's phenotype.

Role of netrin-1 and netrin-1 dependence receptors in colorectal cancers.

Although cancer is a multifaceted disease, all cancer types share identical molecular and cellular mechanisms. These mechanisms involve a collection of alterations critical to the normal physiological functioning of cells, such as alterations of growth factor signalling pathways, angiogenesis, cell adhesion signals, DNA replication and apoptotic cell death. Many genes involved in the processes enumerated above are functionally inactive in tumour cells, designating them as putative 'tumour suppressor genes'. Back in the early 1990s, Vogelstein and colleagues suggested that a gene called DCC (for Deleted in Colorectal Cancer) could be a tumour suppressor gene because it was found to be deleted in more than 70% of colorectal cancers, as well as in many other cancers. During the last 15 years, controversial data have failed to firmly establish whether DCC is indeed a tumour suppressor gene. However, the recent observations that DCC triggers cell death and is a receptor for netrin-1, a molecule recently implicated in colorectal tumorigenesis, have prompted a renewal of interest in the role of DCC in tumorigenesis and suggest that the netrin-1/receptor pairs act as novel negative regulators of tumour development.

Netrin-1 acts as a survival factor via its receptors UNC5H and DCC.

The membrane receptors DCC and UNC5H have been shown to be crucial for axon guidance and neuronal migration by acting as receptors for netrin-1. DCC has also been proposed as a dependence receptor inducing apoptosis in cells that are beyond netrin-1 availability. Here we show that the netrin-1 receptors UNC5H (UNC5H1, UNC5H2, UNC5H3) also act as dependence receptors. UNC5H receptors induce apoptosis, but this effect is blocked in the presence of netrin-1. Moreover, we demonstrate that UNC5H receptors are cleaved in vitro by caspase in their intracellular domains. This cleavage may lead to the exposure of a fragment encompassing a death domain required for cell death induction in vivo. Finally, we present evidence that during development of the nervous system, the presence of netrin-1 is crucial to maintain survival of UNC5H- and DCC-expressing neurons, especially in the ventricular zone of the brainstem. Altogether, these results argue for a role of netrin-1 during the development of the nervous system, not only as a guidance cue but as a survival factor via its receptors DCC and UNC5H.