Amyloid beta peptide-induced inhibition of endothelial nitric oxide production involves oxidative stress-mediated constitutive eNOS/HSP90 interaction and disruption of agonist-mediated Akt activation
Kinesiology & Health Sciences
Journal of Neuroinflammation
Background: Amyloid beta (A beta)-induced vascular dysfunction significantly contributes to the pathogenesis of Alzheimer's disease (AD). A beta is known to impair endothelial nitric oxide synthase (eNOS) activity, thus inhibiting endothelial nitric oxide production (NO). Method: In this study, we investigated A beta-effects on heat shock protein 90 (HSP90) interaction with eNOS and Akt in cultured vascular endothelial cells and also explored the role of oxidative stress in this process. Results: Treatments of endothelial cells (EC) with A beta promoted the constitutive association of HSP90 with eNOS but abrogated agonist (vascular endothelial growth factor (VEGF))-mediated HSP90 interaction with Akt. This effect resulted in blockade of agonist-mediated phosphorylation of Akt and eNOS at serine 1179. Furthermore, A beta stimulated the production of reactive oxygen species in endothelial cells and concomitant treatments of the cells with the antioxidant N-acetyl-cysteine (NAC) prevented A beta effects in promoting HSP90/eNOS interaction and rescued agonist-mediated Akt and eNOS phosphorylation. Conclusions: The obtained data support the hypothesis that oxidative damage caused by A beta results in altered interaction of HSP90 with Akt and eNOS, therefore promoting vascular dysfunction. This mechanism, by contributing to A beta-mediated blockade of nitric oxide production, may significantly contribute to the cognitive impairment seen in AD patients.
Lamoke, F., Mazzone, V., Persichini, T., Maraschi, A., Harris, M. B., Venema, R. C., ... & Mollace, V. (2015). Amyloid β peptide-induced inhibition of endothelial nitric oxide production involves oxidative stress-mediated constitutive eNOS/HSP90 interaction and disruption of agonist-mediated Akt activation. Journal of neuroinflammation, 12(1), 84.