RESUMO
Oxidative stress and increased oxidation of low-density lipoprotein (oxLDL) through free radical-mediated tissue injury may be important factors in the development of extracranial atherosclerotic lesions. However, the roles of oxidative stress and hypercholesterolemia in intracranial atherosclerosis is less established. The induction of heme oxygenase (HO) is a cellular response to oxidative stress, and inducible HO (HO-1) may protect against oxidized lipids such as those produced by oxidative stress. We investigated the effects of oxLDL on cell and tissue viability, HO-1 and ferritin expression in extracranial and intracranial endothelial cells, and the arteries of cholesterol-induced atherosclerosis (CIA) Japanese quail. We report that cultured microvascular endothelial cells from the brain (QBMEC) and carotid (QCEC) differ in their response to oxidative stress. The QCECs are less responsive than QBMECs to oxidative stress induced by oxLDL, as evident by lower expression of HO-1 mRNA, HO activity, and ferritin levels. Furthermore, the higher levels of catalytic iron, thiobarbituric acid reactive substances, and lactate dehydrogenase released in QCECs indicated that these cells are more susceptible to oxidative stress than QBMECs. We also investigated the relationship between extent of atherosclerotic plaque deposition and the extracranial and intracranial arterial expression of HO-1 in quail. The common carotid and vertebral (extracranial) arteries had higher tissue cholesterol levels (starting at 2 weeks of cholesterol-supplementation) and a greater atherosclerotic plaque score (starting at 4 weeks of cholesterol-supplementation) compared with middle cerebral and basilar (intracranial) arteries, and this may be relevant to the effect of aging on the process of atherogenesis. The extracranial arteries also had early and greater levels of lipid peroxidation and catalytic iron coupled with lower expression of HO-1 protein, HO activity, and ferritin compared to the intracranial vessels. These observations suggest that the extracranial and intracranial arterial walls respond differently to oxidation of lipoproteins, and support the feasibility of increased HO-1 expression as a means of protection against oxidant injury.
Assuntos
Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Artérias Cerebrais/metabolismo , Ferritinas/genética , Predisposição Genética para Doença , Heme Oxigenase-1/genética , Arteriosclerose Intracraniana/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Células Cultivadas , Artérias Cerebrais/efeitos dos fármacos , Colesterol/farmacologia , Coturnix , Ativação Enzimática/efeitos dos fármacos , Ferritinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Arteriosclerose Intracraniana/metabolismo , Lipoproteínas LDL/farmacologia , Masculino , Microcirculação/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Fatores de TempoRESUMO
We report here an autopsy case of Binswanger's disease (BD) without hypertension and associated with cerebral infarction in the terminal stage. The female patient, who was 74 years old at the time of death, had initially demonstrated manic-depressive disorder-like mental disorder, followed by dementia and neurological deficits. A brain CT scan showed white matter low attenuation bilaterally and symmetrically. BD was clinically diagnosed despite the lack of hypertension. In the terminal stage, she suffered an infarction in the left anterior cerebral artery region, and died of pneumonia. Neuropathologically, we found the infarction of the left anterior cerebral artery region, demyelination, fibrillary gliosis, lacunae and arteriosclerosis of the small arteries and arterioles in the white matter.