Amyloid β but not bradykinin induces phosphatidylcholine hydrolysis in immortalized rat brain endothelial cells

• Published in: Neuroscience letters Vol. 271; no. 3; pp. 151 - 154
• Main Authors: Anfuso, Carmelina D, Lupo, Gabriella, Alberghina, Mario
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 27.08.1999; Elsevier
• Subjects: Amyloid beta-Peptides - pharmacology; Amyloid-β; Animals; Biological and medical sciences; Bradykinin; Bradykinin - pharmacology; Brain - cytology; Cell Line, Transformed - drug effects; Cell Line, Transformed - metabolism; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; Choline - pharmacokinetics; Endothelial cells; Endothelium - cytology; Free radicals; Free Radicals - metabolism; Fundamental and applied biological sciences. Psychology; Hydrolysis; Peptide Fragments - pharmacology; Phosphatidylcholine; Phosphatidylcholines - metabolism; Rats; Tritium; Vertebrates: nervous system and sense organs; Vitamin E - pharmacology; Phosphatidylcholine; Free radicals; Amyloid-β; Bradykinin; Endothelial cells; Endothelial cell; Rat; Rodentia; Central nervous system; Neuropeptide; In vitro; Free radical; Hydrolysis; Vertebrata; Mammalia; Cell line; β Amyloid protein; Brain (vertebrata)
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(99)00560-1

We describe the inhibitory effect of Aβ (25–35) fragment of amyloid-β peptide and bradykinin (BK) on phosphatidylcholine (PtdCho) metabolism in immortalized rat brain GP8.39 endothelial cells (EC). Cultures were incubated either with Aβ for 24–48 h, or with BK for 30 min–4 h. The peroxidation indices (malondialdehyde, conjugated dienes) and lactate dehydrogenase (LDH) release significantly increased after Aβ peptide (10–50 μM) treatment. The BK (10 μM) stimulation of cells brought about an increase in conjugated dienes and LDH release only after 4 h. Following 24 h treatment with 50 μM Aβ peptide, the [Me– 3H]choline incorporation into PtdCho strongly decreased while the [ 3H]choline release increased, indicating PtdCho hydrolysis. The effect was most likely due to peptide prooxidant effect. After 4 h preincubation with BK, the [Me– 3H]choline incorporation into PtdCho strongly decreased, but no significant [ 3H]choline release was found. Following long-term treatment, the action of 50 μM Aβ on [ 3H]choline release was not enhanced by 10 μM BK. Cell exposure to α-tocopherol (1 mM) prior to the addition of both agents did not abolish stimulated PtdCho breakdown. The data suggest that: (a) Aβ peptide and BK may modulate phospholipid turnover in microvessel cells; (b) they could not synergistically interact in vascular EC damage during processes involving amyloid accumulation and inflammatory response.