AUTHOR=Wang Ting , Yao Yunxia , Han Chao , Li Taoran , Du Wenying , Xue Jinhua , Han Ying , Cai Yanning 

TITLE=MCP-1 levels in astrocyte-derived exosomes are changed in preclinical stage of Alzheimer's disease

JOURNAL=Frontiers in Neurology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1119298

DOI=10.3389/fneur.2023.1119298

ISSN=1664-2295

ABSTRACT=<sec><title>Background</title><p>Alzheimer's disease (AD) is the most common form of dementia in older adults. There is accumulating evidence that inflammatory processes play a critical role in AD pathogenesis. In this study, we investigated whether inflammatory factors in plasma and astrocyte-derived exosomes (ADEs) from plasma are differentially expressed in the early stages of AD and their potential role in pathological processes in the AD continuum.</p></sec><sec><title>Method</title><p>We included 39 normal controls (NCs), 43 participants with subjective cognitive decline (SCD), and 43 participants with amnestic mild cognitive impairment (aMCI)/AD. IL-6, IL-8, and MCP-1 in plasma and ADEs from plasma were evaluated using a commercial multiplex Luminex-based kit.</p></sec><sec><title>Results</title><p>Pairwise comparisons between the groups showed no significant differences in plasma levels of IL-6, IL-8, or MCP-1. However, ADEs in the SCD group showed an increase in MCP-1 levels compared to the NC group. To differentiate the preclinical group, discriminant analysis was performed using sex, age, years of education, and genotype. This revealed a difference between the SCD and NC groups (area under the curve: 0.664). A Spearman correlation analysis of MCP-1 in plasma and ADEs showed no or weak correlation in the SCD (<italic>R</italic> = 0.150, <italic>p</italic> = 0.350) and aMCI/AD (<italic>R</italic> = 0.310, <italic>p</italic> = 0.041) groups, while a positive correlation in the NC group (<italic>R</italic> = 0.360, <italic>p</italic> = 0.026).</p></sec><sec><title>Conclusion</title><p>Plasma IL-6, IL-8, and MCP-1 levels were not significantly different. However, the concentration of MCP-1 in ADEs is slightly altered during the preclinical phase of AD, which could be a potential role of the central neuron system (CNS) immune response in the AD continuum.</p></sec><sec><title>Clinical trial registration</title><p><ext-link ext-link-type="uri" xlink:href="https://www.clinicaltrials.gov/" xmlns:xlink="http://www.w3.org/1999/xlink">www.ClinicalTrials.gov</ext-link>, identifier: NCT03370744.</p></sec>