Biology subjects

Rebeck, G. W.

Publications and source records attributed to Rebeck, G. W..

3 recordsLinked to original sources

bioRxiv2026

Intravenous anti-abeta immunotherapy acutely increases cerebral amyloid angiopathy and vascular damages in APOE4 mice

Anti-A{beta} immunotherapies for Alzheimers Disease (AD) have high rates of amyloid-related imaging abnormalities (ARIA), an adverse side effect with markedly higher rates in APOE4 carriers. We developed a mouse model of ARIA centered on human APOE3 and APOE4 genotypes with amyloidosis (5xFAD transgene) and microglia tagged with green fluorescent protein (from the CX3CR1 promoter). We measured acute changes following a single intravenous treatment with 3D6 anti-A{beta} immunotherapy. Across 82 mice, APOE4 mice showed stepwise reductions in the number of plaques from one to ten days, with significant reductions in the subiculum (48%) and thalamus (40%) at ten days. There was no significant reduction in APOE3 mice. There was a concomitant significant increase in deposition of cerebral amyloid angiopathy (CAA) in APOE4 mice at one (76%) and three (51%) days in leptomeningeal vessels. The increased CAA correlated with a significant 189% increase in A{beta} within microglia of APOE4 (but not APOE3) mice at one day. Smooth muscle actin staining showed significant 58% reduction near CAA. MRI analysis revealed a significant 32% increase in microhemorrhages ten days following treatment. These data demonstrate an APOE4-specific redistribution of parenchymal amyloid to CAA by 3D6 within days, leading to increased vascular damages associated with ARIA.

neuroscience↗

bioRxiv2022

CCR5 deficiency normalizes TIMP levels, working memory, and gamma oscillation power in APOE4 targeted replacement mice

The APOE4 allele increases the risk for Alzheimers disease (AD) in a dose-dependent manner and is also associated with cognitive decline in non-demented elderly controls. In mice with targeted gene replacement (TR) of murine APOE with human APOE3 or APOE4, the latter show reduced neuronal dendritic complexity and impaired learning. APOE4 TR mice also show reduced gamma oscillation power and sharp wave ripple (SWR) abundance, neuronal population activities important to learning and memory. Published work has shown that brain extracellular matrix (ECM) can reduce neuroplasticity as well as gamma power and SWR abundance, while attenuation of ECM can instead enhance these endpoints. In the present study we examine human cerebrospinal fluid (CSF) samples from APOE3 and APOE4 individuals and brain lysates from APOE3 and APOE4 TR mice for levels of ECM effectors that can increase matrix deposition and restrict neuroplasticity. We find that CCL5, a molecule linked to ECM deposition in liver and kidney, is increased in CSF samples from APOE4 individuals. Levels of tissue inhibitor of metalloproteinases (TIMPs), which inhibit the activity of ECM-degrading enzymes, are also increased in APOE4 CSF as well as protein lysates from APOE4 TR mice. Importantly, as compared to wildtype/APOE4 heterozygotes, CCR5 knockout/APOE4 heterozygotes show reduced TIMP levels and enhanced EEG gamma power. The latter also show improved learning and memory, suggesting that the CCR5/CCL5 axis could represent a therapeutic target for APOE4 individuals.

neuroscience↗

bioRxiv2020

Spatial inhibition of return is impaired in mild cognitive impairment and mild Alzheimer's disease

Spatial inhibition of return (IOR) refers to the phenomenon by which individuals are slower to respond to stimuli appearing at a previously cued location compared to un-cued locations. Here we provide evidence supporting that spatial IOR is mildly impaired in individuals with mild cognitive impairment (MCI) or mild Alzheimers disease (AD), and the impairment is readily detectable using a novel double cue paradigm. Furthermore, reduced spatial IOR in high-risk healthy older individuals is associated with reduced memory and other neurocognitive task performance, suggesting that the novel double cue spatial IOR paradigm may be useful in detecting MCI and early AD. SIGNIFICANCE STATEMENTO_LINovel double cue spatial inhibition of return (IOR) paradigm revealed a robust effect IOR deficits in individuals with mild cognitive impairment (MCI) or mild Alzheimers disease (AD) C_LIO_LISpatial IOR effect correlates with memory performance in healthy older adults at a elevated risk of Alzheimers disease (with a family history or APOE e4 allele) C_LIO_LIThe data suggests that double cue spatial IOR may be sensitive to detect early AD pathological changes, which may be linked to disease progress at the posterior brain regions (rather than the medial temporal lobe) C_LI

neuroscience↗