Splice-Switching Antisense Oligonucleotides Reduce LRRK2 Kinase Activity in Human LRRK2 Transgenic Mice

Joanna A Korecka,Ria Thomas,Anthony J Hinrich,Alyssa M Moskites,Zach K Macbain,Penelope J Hallett,Ole Isacson,Michelle L Hastings

doi:10.1016/j.omtn.2020.06.027

Abstract

Parkinson’s disease (PD) is a progressive neurological disorder estimated to affect 7–10 million people worldwide. There is no treatment available that cures or slows the progression of PD. Elevated leucine-rich repeat kinase 2 (LRRK2) activity has been associated with genetic and sporadic forms of PD and, thus, reducing LRRK2 function is a promising therapeutic strategy. We have previously reported that an antisense oligonucleotide (ASO) that blocks splicing of LRRK2 exon 41, which encodes part of the kinase domain, reverses aberrant endoplasmic reticulum (ER) calcium levels and mitophagy defects in PD patient-derived cell lines harboring the LRRK2 G2019S mutation. In this study, we show that treating transgenic mice expressing human wild-type or G2019S LRRK2 with a single intracerebroventricular injection of ASO induces exon 41 skipping and results in a decrease in phosphorylation of the LRRK2 kinase substrate RAB10. Exon 41 skipping also reverses LRRK2 kinase-dependent changes in LC3B II/I ratios, a marker for the autophagic process. These results demonstrate the potential of LRRK2 exon 41 skipping as a possible therapeutic strategy to modulate pathogenic LRRK2 kinase activity associated with PD development.

Highlights

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases
These sites are critical for recognition of the exons by the splicing machinery, which catalyzes the cleavage of the intron and ligation of exons to form the mRNA for translation
In this study, we demonstrate that excluding exon 41 from leucinerich repeat kinase 2 (LRRK2) mRNA, using splice-switching antisense oligonucleotide (ASO) that block exon 41 splicing, reduces RAB10 Th73 phosphorylation and normalizes the LC3B II/I ratios in vivo, potentially as a result of reduced LRRK2 kinase activity

Summary

Introduction

Progressive and debilitating, PD is a movement disorder characterized by tremor, muscular rigidity, and slow and uncontrollable movement These symptoms are associated with loss of dopaminergic neurons in the substantia nigra and deficiency of the neurotransmitter dopamine. The majority of PD cases are idiopathic, with $10% caused by known genetic mutation.[1] The most common genetic risk factors associated with PD, accounting for 1%–2% of all PD cases, occur in the leucinerich repeat kinase 2 (LRRK2) gene, encoding a serine/threonine protein kinase. These mutations are dominantly inherited and mostly cause hyperactivation of the LRRK2 kinase.

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Conclusion