Identification of repurposable cytoprotective drugs for Vanishing White Matter Disease

Abstract

24Vanishing white matter disease (VWMD) is a rare leukodystrophy involving loss of function 25 mutations of the guanine exchange factor eIF2B and typically presenting with juvenile onset. 26We aimed to identify repurposable FDA approved drugs in an in vitro drug screen using 27 patient-derived fibroblasts and induced pluripotent stem cell (iPSC)-derived astrocytes. 28 Dysregulated GADD34 and CHOP were identified in patient fibroblasts and iPSC-derived 29 astrocytes under proteasomal stress conditions. A drug screen from a 2400 FDA approved drug 30 library with EIF2B5 disease patient fibroblasts identified 113 anti-inflammatory drugs as a 31 major class of hits with cytoprotective effects. A panel of potential candidate drugs including 32 berberine, deflazacort, ursodiol, zileuton, guanabenz and Anavex 2-73, and preclinical ISRIB, 33 increased cell survival of MG132-stressed EIF2B2 and EIF2B5 disease VWMD astrocytes, 34 and were further investigated for their effect on the integrated stress response and 35 mitochondrial stress. ISRIB but not other drugs significantly affected eIF2α phosphorylation 36 and GADD34 expression. Ursodiol demonstrated capacity to reduce complex I subunit 37 upregulation, ameliorate oxidative stress, loss of mitochondrial membrane potential and 38 upregulation of eIF2B subunits in VWMD astrocytes, highlighting its potential as a 39 cytoprotective compound for VWMD. 40 41 42

Therapy Trial Design in Vanishing White Matter

“… 4 In addition, proteotoxic ER stress can potentially be reduced by compounds, like ursodiol and several other similar chaperone molecules. 34 Assessment of their potential in VWM mice is ongoing.…”