Microglial-associated responses to comorbid amyloid pathology and hyperhomocysteinemia in an aged knock-in mouse model of Alzheimer’s disease

Journal of Neuroinflammation

David J. Braun¹  Edgardo Dimayuga¹  Linda J. Van Eldik²  Josh M. Morganti² 

[1] Sanders-Brown Center on Aging, University of Kentucky, 101 Sanders-Brown Bldg., 800 S. Limestone Street, 40536, Lexington, KY, USA;Sanders-Brown Center on Aging, University of Kentucky, 101 Sanders-Brown Bldg., 800 S. Limestone Street, 40536, Lexington, KY, USA;Department of Neuroscience, University of Kentucky, Lexington, KY, USA;Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA;

关键词: Alzheimer’s disease;    Amyloid;    Homocysteine;    Hyperhomocysteinemia;    Microglia;    Neuroinflammation;   

DOI  :  10.1186/s12974-020-01938-7

来源: Springer

【 摘 要 】

BackgroundElevated blood homocysteine levels, termed hyperhomocysteinemia (HHcy), is a prevalent risk factor for Alzheimer’s disease (AD) in elderly populations. While dietary supplementation of B-vitamins is a generally effective method to lower homocysteine levels, there is little if any benefit to cognition. In the context of amyloid pathology, dietary-induced HHcy is known to enhance amyloid deposition and certain inflammatory responses. Little is known, however, about whether there is a more specific effect on microglia resulting from combined amyloid and HHcy pathologies.MethodsThe present study used a knock-in mouse model of amyloidosis, aged to 12 months, given 8 weeks of B-vitamin deficiency-induced HHcy to better understand how microglia are affected in this comorbidity context.ResultsWe found that HHcy-inducing diet increased amyloid plaque burden, altered the neuroinflammatory milieu, and upregulated the expression of multiple damage-associated and “homeostatic” microglial genes.ConclusionsTaken together, these data indicate complex effects of comorbid pathologies on microglial function that are not driven solely by increased amyloid burden. Given the highly dynamic nature of microglia, their central role in AD pathology, and the frequent occurrence of various comorbidities in AD patients, it is increasingly important to understand how microglia respond to mixed pathological processes.

【 授权许可】

CC BY