Amylin, Aβ42, and Amyloid in VZV Vasculopathy Cerebrospinal Fluid and Infected Vascular Cells.

BACKGROUND VZV vasculopathy is characterized by persistent arterial inflammation leading to stroke. Studies show that VZV induces amyloid formation that may aggravate vasculitis. Thus, we determined if VZV central nervous system (CNS) infection produces amyloid. METHODS Aβ peptides, amylin, and amyloid were measured in CSF from 16 VZV vasculopathy subjects and 36 stroke controls. To determine if infection induced amyloid deposition, mock- and VZV-infected quiescent primary human perineurial cells (qHPNCs), present in vasculature, were analyzed for intracellular amyloidogenic transcripts/proteins and amyloid. Supernatants were assayed for amyloidogenic peptides and ability to induce amyloid formation. To determine amylin's function during infection, amylin was knocked down with siRNA and viral cDNA quantitated. RESULTS Compared to controls, VZV vasculopathy CSF had increased amyloid that positively correlated with amylin and anti-VZV antibody levels; Aβ40 was reduced and Aβ42 unchanged. Intracellular amylin, Aβ42, and amyloid were seen only in VZV-infected qHPNCs. VZV-infected supernatant formed amyloid fibrils following addition of amyloidogenic peptides. Amylin knockdown decreased viral cDNA. CONCLUSIONS VZV infection increased levels of amyloidogenic peptides and amyloid in CSF and qHPNCs, indicating that VZV-induced amyloid deposition may contribute to persistent arterial inflammation in VZV vasculopathy. In addition, we identified a novel proviral function of amylin.