Fas and Fas ligand expression in Alzheimer's disease.
The Fas/Fas ligand (L) signaling system has been implicated in the control of cell death and cell survival of T and B lymphocytes and in a variety of cell types under particular pathological conditions. In the present study we examined the expression of Fas and Fas-L, by Western blotting and immunohistochemistry, in the human frontal cortex and hippocampus of individuals with advanced Alzheimer's disease (AD) and age-matched controls. Expression levels of Fas and Fas-L, as seen in Western blots, are preserved in the frontal cortex but decreased in the hippocampus in AD when compared with age-matched controls. Yet Fas and Fas-L immunoreactivity is found in remaining AD neurons in the frontal cortex and hippocampus. Moreover, Fas and Fas-L are expressed equally in tangle-bearing and non-tangle-bearing neurons, as revealed with double-labeling immunohistochemistry to Fas or Fas-L and tau or phosphorylated neurofilament epitopes. Dystrophic neurites of senile plaques are not stained with Fas and Fas-L antibodies. A moderate increase in Fas and a strong increase in Fas-L immunoreactivity occur in reactive astrocytes in AD. Yet there is no relationship between Fas or Fas-L expression and increased nuclear DNA vulnerability as revealed with double-labeling immunohistochemstry and in situ end-labeling of nuclear DNA fragmentation. Although the Fas/Fas-L system may have some effect in the control of reactive astrocytosis in AD, the present results show no evidence that Fas/Fas-L signals participate in specific processes of the disease, including neurofibrillary degeneration, dystrophic neurite formation, and cell death.
Ferrer
I
I
Unitat de Neuropatologia, Servei d'Anatomia Patològica, Hospital Princeps d'Espanya, Hospitalet de Llobregat, Barcelona, Spain. iferrer@sakma.es
Puig
B
B
Krupinsk
J
J
Carmona
M
M
Blanco
R
R
D000368:Aged; D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D053938:DNA Fragmentation / Q000235:genetics; D053222:Fas Ligand Protein; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D015870:Gene Expression / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D020244:Infarction, Middle Cerebral Artery / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D016874:Neurofibrillary Tangles / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D058225:Plaque, Amyloid / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*; D013347:Subcellular Fractions / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism*
C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D019014:fas Receptor