ABSTRACT
Expression of apoptosis-associated proteins p53, bcl-2, bax, and caspase-3/CPP32, activation of caspase-3, and modification of proteins via poly(ADP-ribosyl)ation was studied in pontosubicular neuron necrosis (PSN), a form of perinatal brain damage revealing the morphological hallmarks of neuronal apoptosis. Immunoreactivity for p53 was completely absent. The majority of cells stained with the bax and procaspase-3 antibodies did not show morphological signs of apoptosis. In contrast, an antibody against activated caspase-3 almost exclusively stained cells with apoptotic morphology. Poly(ADP-ribosyl)ated proteins were only rarely detected in cells with apoptotic morphology. The expression patterns of bax, procaspase-3, bcl-2, and p53 in PSN were similar to that found in age-matched control brains. However, activated caspase-3 and poly-ADP-ribosylated proteins were exclusively found in apoptotic cells. These data indicate that detection of active caspase-3 is a reliable marker for apoptosis in formalin-fixed human tissue, and that neuronal apoptosis in pontosubicular neuron necrosis is accompanied by a pronounced activation of caspase-3.
Subject(s)
Apoptosis/physiology , Caspases/biosynthesis , Enzyme Precursors/biosynthesis , Fetal Hypoxia/pathology , Hippocampus/pathology , Nerve Tissue Proteins/biosynthesis , Neurons/pathology , Pons/pathology , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Proto-Oncogene Proteins/biosynthesis , Tumor Suppressor Protein p53/biosynthesis , Biomarkers , Caspase 3 , Caspases/genetics , Enzyme Activation , Enzyme Precursors/genetics , Female , Fetal Death/metabolism , Fetal Death/pathology , Fetal Hypoxia/metabolism , Fixatives/pharmacology , Formaldehyde/pharmacology , Gene Expression Profiling , Genes, bcl-2 , Genes, p53 , Hippocampus/metabolism , Humans , Infant, Newborn , Male , Nerve Tissue Proteins/genetics , Neurons/metabolism , Poly Adenosine Diphosphate Ribose/analysis , Poly(ADP-ribose) Polymerases/metabolism , Pons/metabolism , Proto-Oncogene Proteins/genetics , bcl-2-Associated X ProteinABSTRACT
Oligodendrocyte and axon pathology was studied in 11 autopsy cases of clinically silent multiple sclerosis. A total of 54 lesions, either demyelinated or late remyelinated, were distributed through the whole brain and spinal cord with 39% of the lesions located in periventricular areas. Determination of axon density revealed an average reduction of 64% and 59% in demyelinated and remyelinated lesions with an extreme variation between different plaques and cases. Oligodendrocytes were identified by immunocytochemistry for myelin oligodendrocyte glycoprotein (MOG) and in situ hybridization for proteolipid protein (PLP) mRNA. Oligodendrocytes were almost completely lost in demyelinated lesions; remyelinated lesions revealed preservation of a considerable number of oligodendrocytes within the lesions. At the border between plaques and the periplaque white matter, similar oligodendrocyte numbers as in remyelinated lesions were found. Different factors including lesion site, axonal preservation and remyelination may thus contribute to the clinical nonappearance of multiple sclerosis lesions.
