Acceleration of Circulatory and Neurological Aging due to Wildfire Exposures

SUMMARY: Acceleration of Circulatory and Neurological Aging due to Wildfire Exposures
Wildfires pose an increasing threat to a growing and aging global population, notably in the Western United
States. Little is known about the influence of inhaled environmental pollutants, such as from wildfire smoke
(WFS) exposure, on molecular pathways governing cerebrovascular and neurological aging in the etiology of
Alzheimer’s disease (AD) and dementia. Yet, parallel molecular changes are induced by aging and inhaled
toxicants within the blood, raising the potential for their negative interaction. This includes increased
metalloproteinases, serpins and inflammatory factors that can directly promote age-related neurological
pathologies. Moreover, our research documents how inhaled pollutants cause blood compositional changes,
particularly as protease-induced peptides, that promote vascular dysfunction and neurological inflammation.
Inhaled toxicant induced circulating factors promote blood-brain barrier (BBB) permeation, glial activation and
pro-inflammatory secretion and recruitment, and elevation of AD markers such as amyloid beta. Inhaled
toxicant and age-related BBB deficits and associated sequelae show common involvement for vascular cell
adhesion molecule-1 (VCAM-1), which is directly increased on cerebrovascular endothelial cells following
exposure to WFS. Thus, we hypothesize that WFS augments pathological aging outcomes of senescence-
associated secretory proteins in the circulating milieu to advance BBB compromise, neuroinflammation, and
prime AD pathogenesis principally through expression/activity of cerebrovascular VCAM-1. To test this
hypothesis, our team proposes the following aims: 1. Assess interaction between WFS exposure-induced and
aging-related circulatory changes as drivers of BBB impairment, neuroinflammation, and early evidence of
amyloid and tau proteinopathy. Serum compositional changes caused by aging x WFS exposure will be
comprehensively assessed at the protein, peptide and metabolite levels and paired with in vivo histopathology
and functional ex vivo phenotyping of major hallmarks of neurological and cardiovascular aging. 2. Delineate
the role of cerebrovascular endothelial receptors, namely CD36, as intermediates in WFS-induced
neuroinflammation. CD36 is clearly involved in acute responses of the BBB to inhaled toxicants, and likely to
upregulation of VCAM-1, which has been recently implicated as a mediator of aging-related neurological
sequelae. 3. Pharmacologically attenuate accelerated aging from WFS exposure using a sirtuin-1 activator
(resveratrol) with an NAD+ booster (NMN) and/or a senolytic cocktail to reduce aging-related circulating
factors. These permutations will target the key outcomes of circulatory changes from WFS exposure in target
cells (vascular, neural) to reduce early pro-AD pathogenic BBB compromise, neuroinflammation and
proteinopathy related outcomes. Together, findings will detail the influence of WFS in advancing age-related
AD pathogenesis by generating vascular-compromising and glial-stimulating factors in the circulation, and
evaluate counteracting therapeutics for use following unavoidable WFS exposure.

Grant Number: 5R01AG070776-04
NIH Institute/Center: NIH
Principal Investigator: Matthew Campen