White matter hyperintensities and the surrounding normal appearing white matter are associated with water channel disruption in the oldest old

© 2024 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association..

INTRODUCTION: Age-related magnetic resonance imaging (MRI) T2 white matter hyperintensities (WMHs) are common and associated with neurological decline. We investigated the histopathological underpinnings of MRI WMH and surrounding normal appearing white matter (NAWM), with a focus on astroglial phenotypes.

METHODS: Brain samples from 51 oldest old Oregon Alzheimer's Disease Research Center participants who came to autopsy underwent post mortem (PM) 7 tesla MRI with targeted histopathological sampling of WMHs and NAWM. Stained slides were digitized and quantified. Mixed-effects models determined differences in molecular characteristics between WMHs and the NAWM and across NAWM.

RESULTS: PM MRI-targeted WMHs are characterized by demyelination, microglial activation, and prominent astrocytic alterations, including disrupted aquaporin (AQP) expression. Similar changes occur within the surrounding NAWM in a pattern of decreasing severity with increased distance from WMHs.

DISCUSSION: Decreased AQP expression within WMH and proximal NAWM suggest an overwhelmed system wherein water homeostasis is no longer maintained, contributing to WM damage in older individuals.

HIGHLIGHTS: Post mortem magnetic resonance imaging (MRI) was used to characterize the pathology of white matter hyperintensities (WMHs) and surrounding normal appearing white matter (NAWM). Stained immunohistochemical (IHC) slides from targeted WMH and NAWM samples were digitized and quantified. WMHs and NAWM were associated with inflammation, demyelination, and gliosis. WMHs and NAWM astrocytic changes included decreased AQP1 and AQP4 expression. Abnormal NAWM pathology diminished in severity with increasing distance from WMH.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - year:2024

Enthalten in:

Alzheimer's & dementia : the journal of the Alzheimer's Association - (2024) vom: 17. Apr.

Sprache:

Englisch

Beteiligte Personen:

Silbert, Lisa C [VerfasserIn]
Roese, Natalie E [VerfasserIn]
Krajbich, Victoria [VerfasserIn]
Hurworth, Justin [VerfasserIn]
Lahna, David [VerfasserIn]
Schwartz, Daniel L [VerfasserIn]
Dodge, Hiroko H [VerfasserIn]
Woltjer, Randall L [VerfasserIn]

Links:

Volltext

Themen:

Aquaporin
Journal Article
Magnetic resonance imaging
Oldest old
Pathology
White matter hyperintensity

Anmerkungen:

Date Revised 17.04.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1002/alz.13816

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM371189926