Cullen Abigail E, Reeve Emily H, Winder Nick R, Henson Grant D, Arora Nayantara, Leonhardt Thomas, Hogan Ainsley, Kumaran Sahana Krishna, Setthavonsack Naly, Krajbich Victoria, Alkayed Nabil J, Pike Martin M, Woltjer Randall L, Walker Ashley E
Human Physiology, University of Oregon, Eugene, OR, USA.
Pathology and Laboratory Medicine, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
bioRxiv. 2025 Aug 22:2025.08.18.670895. doi: 10.1101/2025.08.18.670895.
Artery structural properties and Alzheimer's disease (AD) pathology are individually associated with impaired cerebrovascular function; however, the interaction of these factors is unclear. Furthermore, while elastin haploinsufficient ( ) mice are known to have impaired cerebrovascular function, sex differences for this effect have not been previously studied. To answer these questions, we crossed middle-aged and old mice with 3xTg-AD mice. We measured cerebral blood flow (CBF) using arterial spin labeling MRI at rest and during hypercapnia to calculate cerebrovascular reactivity (CVR). We also assessed neuroinflammation by microglia and astrocyte cell counts. We found that mice had lower resting blood flow rate in the cerebral cortex compared with mice, but mice had an intact hypercapnic response, resulting in better CVR compared with in hippocampus. Sex did not impact resting blood flow or CVR. 3xTg-AD mice had a lower resting CBF than non-AD mice, and there was an interaction between genotype and AD mutations on CVR, such that x 3xTg-AD mice had the poorest hippocampal CVR of all groups. Glia cell counts were highly dependent on brain region, with having more microglia but fewer astrocytes, while 3xTg-AD having higher both microglia and astrocytes. While sex also impacted glial cell counts, we found no interactions between sex and genotype. Our results demonstrate that elastin haploinsufficiency and AD mutations individually result in lower resting CBF, and the combination of these leads to impaired CVR.
动脉结构特性与阿尔茨海默病(AD)病理各自与脑血管功能受损相关;然而,这些因素之间的相互作用尚不清楚。此外,虽然已知弹性蛋白单倍体不足( )小鼠存在脑血管功能受损,但此前尚未研究过这种效应的性别差异。为了回答这些问题,我们将中年和老年 小鼠与3xTg-AD小鼠进行杂交。我们使用动脉自旋标记MRI在静息状态和高碳酸血症期间测量脑血流量(CBF),以计算脑血管反应性(CVR)。我们还通过小胶质细胞和星形胶质细胞计数评估神经炎症。我们发现,与 小鼠相比, 小鼠大脑皮层的静息血流速率较低,但 小鼠具有完整的高碳酸血症反应,与 小鼠相比,海马体中的CVR更好。性别对静息血流或CVR没有影响。3xTg-AD小鼠的静息CBF低于非AD小鼠,并且 基因型与AD突变对CVR存在相互作用,使得 x 3xTg-AD小鼠在所有组中具有最差的海马体CVR。胶质细胞计数高度依赖于脑区, 小鼠的小胶质细胞较多但星形胶质细胞较少,而3xTg-AD小鼠的小胶质细胞和星形胶质细胞都较多。虽然性别也影响胶质细胞计数,但我们未发现性别与 基因型之间存在相互作用。我们的结果表明,弹性蛋白单倍体不足和AD突变各自导致静息CBF降低,而两者结合会导致CVR受损。