RESUMEN
Common genetic risk factors are associated with frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Intermediate repeat expansions at the Ataxin-2 locus (ATXN2) are a risk factor for ALS and influence the phenotype. We assessed whether ATXN2 is a risk factor for FTD or modify clinical features in a data set of Italian patients. Three hundred sixty-eight unrelated FTD cases and 342 controls were enrolled. The frequency of intermediate CAG repeats in ATXN2 gene was not different comparing patients and controls. CAG repeats were interrupted by CAA in all patients carrying intermediate repeats. Interestingly, patients with an increased number of CAG repeats had an earlier onset of the disease than those without expansions (p = 0.011), and presented more frequently with parkinsonism (p = 0.010), and psychotic symptoms (p = 0.013) at disease onset. Our study does not support a major role of ATXN2 intermediate CAG expansions in predisposing to FTD but suggests that ATXN2 may act as a phenotype modifier.
Asunto(s)
Ataxina-2/genética , Demencia Frontotemporal/genética , Estudios de Asociación Genética , Expansión de Repetición de Trinucleótido/genética , Anciano , Femenino , Humanos , Masculino , Fenotipo , Factores de RiesgoRESUMEN
The oncoprotein E7 from human papillomavirus-16 (HPV-16 E7) plays a pivotal role in HPV postinfective carcinogenesis, and its physical interaction with host cell targets is essential to its activity. We identified a novel cellular partner for the viral oncoprotein: the actin-binding protein gelsolin (GSN), a key regulator of actin filament assembly and disassembly. In fact, biochemical analyses, generation of a 3D molecular interaction model and the use of specific HPV-16 E7 mutants provided clear cut evidence supporting the crucial role of HPV-16 E7 in affecting GSN integrity and function in human immortalized keratinocytes. Accordingly, functional analyses clearly suggested that stable HPV-16 E7 expression induced an imbalance between polymeric and monomeric actin in favor of the former. These events also lead to changes of cell cycle (increased S phase), to the inhibition of apoptosis and to the increase of cell survival. These results provide support to the hypotheses generated from the 3D molecular interaction model and encourage the design of small molecules hindering HPV-induced host cell reprogramming by specifically targeting HPV-16 E7-expressing cells.