Activation of microglia in the brains of humans with heart disease and hypercholesterolemic rabbits

• Published in: Journal of molecular medicine (Berlin, Germany) Vol. 75; no. 2; pp. 130 - 138
• Main Authors: Streit, W. J., Sparks, D. Larry
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.02.1997
• Subjects: Aged; Aging; Alzheimer Disease - blood; Alzheimer Disease - etiology; Alzheimer Disease - immunology; Alzheimer Disease - pathology; Animals; Biological and medical sciences; Brain - pathology; Disorders of blood lipids. Hyperlipoproteinemia; Heart Diseases - blood; Heart Diseases - complications; Heart Diseases - immunology; Heart Diseases - pathology; Humans; Hypercholesterolemia - complications; Hypercholesterolemia - immunology; Hypercholesterolemia - pathology; Immunohistochemistry; Medical sciences; Metabolic diseases; Microglia - immunology; Microglia - pathology; Middle Aged; Rabbits; Lectin; Senescence; Senile plate; Cholesterolemia; Alzheimer disease; Major histocompatibility system; Rabbit; Cardiovascular disease; Metabolic diseases; Lipids; Hyperlipoproteinemia; Lagomorpha; Gene expression; Microglia; Vertebrata; Mammalia; Hypercholesterolemia; Animal; Heart disease; Dyslipemia; Coloration; Brain (vertebrata)
• ISSN: 0946-2716; 1432-1440
• DOI: 10.1007/s001090050097

Activated microglial cells are concentrated in senile plaques characteristic of Alzheimer's disease. Such accumulations of activated microglia may contribute towards neurodegeneration via production of cytokines and free radicals. Studies suggesting a link between Alzheimer's disease and heart disease led us to study microglia immunohistochemically, using monoclonal antibody LN-3, in age-matched nondemented humans with and without heart disease. Using a qualitative staging system for assessing morphological changes occurring in microglia, we found higher microglial activation in the brains of subjects with heart disease than in those without it. Lectin histochemical examination of brains from rabbits maintained on a high-cholesterol diet also revealed increased microglial activation and leukocyte infiltration. Collectively our observations from humans and rabbits suggest that hypercholesterolemia and heart disease accelerate brain aging, and that the formation of senile plaques may be the end result of progressive microglial activation that occurs with aging.