title: Actin in semithin sections of myocardial biopsies as a tool to visualize myofibrillary degradation in humans.
abstract: Dilated cardiomyopathy (DCM) is characterized by dilation of ventricular walls and the reduction of cardiac contractillity, caused by loss of myofibrils and apoptosis of the myocytes. Histochemical assessment of myocardial biopsies is commonly used to monitor these events. Here we report the use of immunohistochemistry for alpha-actin in semithin serial sections of myocardial biopsies taken from patients with various stages of DCM. This technique allows also the detection of DNA-fragmentation and tissue transglutaminase as markers for cell damage in subsequent sections of the same myocytes. Intense actin immunostaining was observed only in the cytoplasm of cells that also expressed tissue transglutaminase in the cytoplasm and showed DNA-fragmentation in the nucleus. We assume that endogenous proteolysis, associated with apoptotic events enhances the stainability of actin in semithin sections. High resolution detection of actin probably visualizes myofibrillary deterioration, which may correspond to reduced cardiac performance in a more direct manner than the histochemistry of apoptotic markers.
authors.affiliation: Institute of Anatomie II, Friedrich-Schiller-University, Teichgraben, Jena, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Busch
authors.forename: G F
authors.initials: GF
authors.lastname: Jirikowski
authors.forename: A P
authors.initials: AP
authors.lastname: Aschoff
authors.forename: U
authors.initials: U
authors.lastname: Lotze
mesh_terms: D000199:Actins / Q000378:metabolism*; D017209:Apoptosis; D015415:Biomarkers; D002311:Cardiomyopathy, Dilated / Q000378:metabolism* / Q000473:pathology*; D053938:DNA Fragmentation; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology*; D009210:Myofibrils / Q000378:metabolism* / Q000473:pathology*; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases / Q000378:metabolism
chemical_list: D000199:Actins; D015415:Biomarkers; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins