Project Summary/Abstract
Intracerebral hemorrhage (ICH) is a severe neurological disorder with no proven treatment. There is
increasing evidence that inflammation contributes to ICH outcomes, but the underlying mechanisms remain
largely unknown. ICH disproportionately affects ethnic/racial minorities and young people. Our preliminary data
confirms reports that ICH survivors have a high rate of progressive cognitive decline, plausibly initiated by the
aggressive ICH inflammatory response. Exosomes are extracellular vesicles released from cells into the
circulating blood; by analyzing exosomes released from neurons and microglia, brain-specific inflammatory
pathophysiology can be assessed by testing circulating plasma. Exosomes transport microRNA (miRNA) that
are powerful regulators of gene expression. In our preliminary studies, three inflammatory mediators emerged
as particularly salient in post-ICH inflammation and promising for additional analysis in a larger study: monocytes,
interleukin-8 (IL-8), and miRNA (miR)-181a. We propose the CAPSTONE (Central And Peripheral STrOke
inflammatioN with Exosomes) study that will enroll 250 ICH subjects previously recruited into the ROSE-LAWN
study (Recovery of StrokE, Longitudinal Assessment With Neuroimaging, R01NS120493). CAPSTONE will
utilize plasma, peripheral blood, and functional/cognitive outcomes from ROSE-LAWN; serial plasma and blood
samples will be analyzed from baseline, three months, and 18 months after ICH.
Through the following aims, we will pursue our overall goal to identify transcriptomic biomarkers associated
with six-month functional outcome and long-term progressive cognitive decline. Specific Aim 1 will determine
miRNA in neuronal- and microglial-derived exosomes that correlate with six-month functional outcome and long-
term progressive cognitive decline (~24 months after ICH). We hypothesize that decreased miR-181a in neuronal
and microglial exosomes will predict worse near-term functional outcome and greater long-term cognitive
decline. Specific Aim 2 will determine mRNA and miRNA in peripheral leukocytes that correlate with six-month
functional outcome and long-term progressive cognitive decline (~24 months after ICH). We hypothesize that
decreased miR-181a and increased CXCL8 and IL-8 will predict worse functional outcome and greater long-term
cognitive decline. Specific Aim 3 will explore the interactions between central and peripheral inflammatory
processes post-ICH. We hypothesize that decreased miR-181a in neuronal- and microglial-derived exosomes
will be associated with increased CXCL8 and IL-8 from peripheral leukocytes.
Post-ICH inflammation is an interplay of both brain-derived and systemic pathology, but the associated
molecular mechanisms remain poorly understood. By analyzing circulating blood (i.e., systemic) and cell-specific
exosomes in plasma (i.e., brain derived), CAPSTONE seeks to provide substantial insight regarding these
inflammatory processes. This research also addresses the NINDS priorities of recovery, imaging, and vascular
cognitive impairment.