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Alia, A. O.

Publications and source records attributed to Alia, A. O..

2 recordsLinked to original sources

ACE1 Does Not Influence Cerebral Aβ Degradation or Amyloid Plaque Accumulation in 5XFAD Mice

Alzheimers disease (AD) is the most common form of dementia, and multiple lines of evidence support the relevance of A{beta} deposition and amyloid plaque accumulation in the neurotoxicity and cognitive decline in AD. Rare mutations in angiotensin-converting-enzyme-1 (ACE1) have been highly associated with late onset AD patients; however, the mechanism for ACE1 mutation in AD pathogenesis is unknown. Given the relevance of ACE1 with AD and the strong association of A{beta} to AD pathogenesis, we investigated whether ACE1 degrades A{beta} and affects amyloid burden in 5XFAD mice in vivo. To investigate this, we analyzed 6-month-old 5XFAD mice with ACE1 loss of function. ACE1 loss of function was mediated either by crossing 5XFAD mice to ACE1 conditional knockout mice or administering 5XFAD mice with the ACE1 inhibitor enalapril. Our analyses revealed that ACE1 loss of function through both genetic and pharmacological methods does not affect amyloid plaque load and neuroinflammation in the hippocampus and cortex of 5XFAD mice.

neuroscience↗

ACE1 knockout in neurons selectively dysregulates the hippocampal renin angiotensin system and causes vascular loss

Angiotensin I converting enzyme (ACE1) maintains blood pressure homeostasis by converting angiotensin I (angI) into angiotensin II (angII) in the renin-angiotensin system (RAS). ACE1 is expressed in the brain, where an intrinsic RAS regulates complex cognitive functions including learning and memory. ACE1 has been implicated in neurodegenerative disorders including Alzheimers disease (AD) and Parkinsons disease (PD), but the mechanisms remain incompletely understood. Here, we performed single-nucleus RNA sequencing to characterize the expression RAS genes in the hippocampus and discovered that Ace is mostly expressed in CA region excitatory neurons. To gain a deeper understanding of the function of neuronal ACE1, we generated ACE1 conditional knockout (cKO) mice lacking ACE1 expression specifically in hippocampal and cortical excitatory neurons. Interestingly, ACE1 cKO mice exhibited hippocampus-dependent memory impairment in the Morris water maze, y-maze, and fear conditioning tests, but exhibited normal motor skills in rotarod. Total ACE1 level was significantly reduced in the cortex and hippocampus of ACE1 cKO mice showing that excitatory neurons are the predominant cell type expressing ACE1 in the forebrain. Despite similar reductions in total ACE1 level in both the hippocampus and cortex, the RAS pathway was dysregulated in the hippocampus only. Importantly, ACE cKO mice exhibited exacerbated age-related capillary loss selectively in the hippocampus. Here, we show selective vulnerability of the hippocampal microvasculature and RAS pathway to neuronal ACE1 knockout. Our results provide important insights into the function of ACE1 in the brain and demonstrate a connection between neuronal ACE and cerebrovascular function in the hippocampus.

neuroscience↗