Antisense Oligonucleotide-Induced Amyloid Precursor Protein Splicing Modulation as a Therapeutic Approach for Dutch-Type Cerebral Amyloid Angiopathy.

Elena Daoutsali,Marcel M Verbeek,Thomas De Vlaam,Linda M Van Der Graaf,Ronald A.M Buijsen,Willeke M.C Van Roon-Mom,Tsinatkeab T Hailu,Barry A Pepers,Daniel Curtis

doi:10.1089/nat.2021.0005

Abstract

Dutch-type cerebral amyloid angiopathy (D-CAA) is a monogenic form of cerebral amyloid angiopathy and is inherited in an autosomal dominant manner. The disease is caused by a point mutation in exon 17 of the amyloid precursor protein (APP) gene that leads to an amino acid substitution at codon 693. The mutation is located within the amyloid beta (Aβ) domain of APP, and leads to accumulation of toxic Aβ peptide in and around the cerebral vasculature. We have designed an antisense oligonucleotide (AON) approach that results in skipping of exon 17, generating a shorter APP isoform that lacks part of the Aβ domain and the D-CAA mutation. We demonstrate efficient AON-induced skipping of exon 17 at RNA level and the occurrence of a shorter APP protein isoform in three different cell types. This resulted in a reduction of Aβ40 in neuronally differentiated, patient-derived induced pluripotent stem cells. AON-treated wild-type mice showed successful exon skipping on RNA and protein levels throughout the brain. These results illustrate APP splice modulation as a promising therapeutic approach for D-CAA.

Highlights

Dutch-type cerebral amyloid angiopathy (D-CAA), previously known as hereditary cerebral hemorrhage with amyloidosis-Dutch type, is a rare autosomal dominant disease, characterized by recurring strokes and dementia
antisense oligonucleotide (AON) transfection in D-CAA fibroblasts showed a prominent skip on RNA level at all concentrations, while in both SH-SY5Y cells and D-CAA neuronally differentiated induced pluripotent stem cells (iPSCs) a dose-dependent increase in exon 17 skipping was observed with a simultaneous decrease of the amyloid precursor protein (APP)-wt transcript (41%– 87.8% and 8.2%–39.8%, respectively)
We show successful and efficient removal of the D-CAA mutation and the y-secretase cleavage site from the APP protein using AON-mediated splice modulation both in vitro and in vivo

Summary

Introduction

Dutch-type cerebral amyloid angiopathy (D-CAA), previously known as hereditary cerebral hemorrhage with amyloidosis-Dutch type, is a rare autosomal dominant disease, characterized by recurring strokes and dementia. It occurs mainly in families from two coastal villages in the Netherlands [1,2], as well as in families in Southwest Australia [3]. It is caused by a point mutation at codon 693 of the amyloid precursor protein (APP) gene resulting in a G to C change (NM_000484.3(APP): c.2077G>C). The first hemorrhagic stroke is fatal within 1 year in one-third of the patient population, whereas surviving patients suffer from recurrent strokes and vascular dementia [4]

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