Myocardial Infarction Predisposes Neurodegenerative Diseases.

Cardiovascular disorders, e.g., atherosclerosis and hypertension, increase susceptibility to neurodegenerative diseases, like dementia and Alzheimer's disease (AD), with undetermined mechanisms. Moreover, whether myocardial infarction (MI) may similarly increases occurrence of AD is unknown. In the current study, we performed a MI model in wild-type and AD-prone APP/PS1 mice and assessed the development of AD in these mice. We found that MI-treated mice of both wild-type and APP/PS1 behaved poorer in a social recognition test, the Morris water maze, and the plus-maze discriminative avoidance task, compared to sham-treated controls. Mechanistically, MI significantly increased the levels of reactive oxygen species, as well as increased deposition of amyloid-β peptide aggregates and phosphorylation of tau protein in mouse brain, two signature pathological features for AD. Moreover, the microglia in the MI-mice appeared to alter polarization to a more proinflammatory phenotype. Together, our data suggest that MI may be a predisposing factor for AD development.