Localization of the apoptosis repressor ARC and anti-apoptotic factor FLIP in endomyocardial biopsies of cardiomyopathy patients / Localización del represor de apoptosis ARC y del factor anti-apoptósico FLIP en biopsias endomiocárdicas de pacientes con cardiomiopatía

ABSTRACT

Endomyocardial biopsies from patients with dilated cardiomyopathy were obtained by cardiac catheterization. Tissue samples were embedded in epoxy resin and sectioned into serial semithin sections for immunohistochemical visualization of either the apoptosis repressor protein or the FLICE inhibitory protein. Colocalization of apoptosis repressor protein and FLICE inhibitory protein was observed in cardiac myocytes, with nuclear DNA fragmentation and myofibrillary degradation. Intact myocytes were devoid of FLICE inhibitory protein and apoptosis repressor protein staining. FLICE (Fas-associated death-domain-like IL-1-converting enzyme) inhibitory protein and apoptosis repressor protein were localized in the perinuclear cytoplasm, mainly in areas that showed myofibrillary degradation as visualized by fluorescence microscopy. FLICE inhibitory and apoptosis repressor proteins may be intracellular markers for monitoring myocardial damage in several cardiac diseases in humans (AU)

RESUMEN

Se obtuvieron biopsias endomiocárdicas de pacientes con cardiomiopatía prolongada mediante cateterización cardíaca. Las muestras de tejido fueron incluidas en resina epoxi y se hicieron cortes semifinos seriados para la visualización inmunohistoquímica de la proteína represora de apoptosis o la proteína inhibidota FLICE. Se observó la colocalización de la proteína represora de apoptosis y la proteína inhibidora FLICE en los miocitos cardíacos, con fragmentación nuclear del DNA y degradación miofibrilar. Los miocitos intactos carecieron de tinción para la proteína inhibidora FLICE y la proteína represora de apoptosis. La proteína inhibidora FLICE (Fas-associated death-domain-like IL-1 -converting enzyme) y la proteína represora de apoptosis se localizaron en el citoplasma perinuclear, principalmente en áreas que mostraban degradación miofibrilar, según se observó mediante microscopía de fluorescencia. Ambas proteínas pueden ser marcadores intracelulares para vigilar y valorar el daño miocárdico en diversas enfermedades cardíacas en humanos (AU)