DNA and RNA are the fundamental nucleic acids that contain and regulate the expression of genetic information within cells.  In recent years it has become clear that short forms (oligonucleotides) of RNA which don’t encode protein, in the form of single-stranded antisense or double-stranded RNA molecules, play an important role in regulating the flow of genetic information. Not only is this of great biological interest but such short nucleic acids have great potential as exogenous regulators of gene expression that could be investigated for therapeutic purposes.

We are interested in understanding the potential of nucleic acid based gene therapy within the neuromuscular system, where it has great promise for both basic research and therapeutic applications.  Non-viral nucleic acid delivery methods are being developed, but in general a wide range of viral vectors provide the most reliable, highest efficiency gene delivery to neurons, other neural cells and muscle in vitro and in vivo.  These vectors allow the replacement, expression or silencing of target genes, and thereby alter the physiological state of specific cell populations.

Available vectors differ in their suitability for different applications, depending on factors such as transgene/nucleic acid size, delivery route, tropism, duration and regulation of gene expression, and side effects.

Current Research Programme

Our current research programme is focussed on nucleic acid-based gene silencing and gene modification, and nucleic acid delivery to the neuromuscular system; this has great potential for both basic neuromuscular research and future therapeutic development.

The recent discovery of endogenous gene silencing mechanisms known as RNA interference (RNAi) now provides a powerful tool for targeted gene suppression, although little is known about the biology of this pathway in the mammalian neuromuscular system.  In addition, a novel application of single stranded antisense oligonucleotides is to modify mRNA splicing, so-called exon skipping. 

The major therapeutic focus of the research programme is currently Parkinson’s disease (PD), neuromuscular junction (NMJ) disease and Duchenne muscular dystrophy (DMD); the key aims of which are:

• To investigate antisense oligonucleotide delivery to muscle, exploring peptide and glycoconjugate libraries
• To investigate siRNA and expressed shRNA delivery to muscle and to the central nervous system (specifically to dopamine neurons of the midbrain), using both non-viral and viral approaches. The viral approaches utilise mainly AAV and lentivirus vectors
• To study the cell biology of RNAi mediated gene silencing in neurons, in particular the role of cytoplasmic RNA processing bodies or P-bodies
• To study antisense-mediated exon-skipping of dystrophin in models of DMD, focussing on muscle targeting and also exon-skipping in heart
• To study RNAi based silencing of dominant disease genes in hereditary myasthenic disorders of the NMJ (e.g. muscle AChR)
• To study RNAi based silencing of dominant disease target genes implicated in PD pathogenesis (e.g. alpha synuclein and LRRK2) in midbrain dopamine neurons

Matthew Wood