Antisense-mediated splice intervention to treat human disease: the odyssey continues [version 1; peer review: 3 approved]

Recent approvals of oligonucleotide analogue drugs to alter gene expression have been welcomed by patient communities but not universally supported. These compounds represent a class of drugs that are designed to target a specific gene transcript, and they include a number of chemical entities to evoke different antisense mechanisms, depending upon the disease aetiology. To date, oligonucleotide therapeutics that are in the clinic or at advanced stages of translation target rare diseases, posing challenges to clinical trial design, recruitment and evaluation and requiring new evaluation paradigms. This review discusses the currently available and emerging therapeutics that alter exon selection through an effect on pre-mRNA splicing and explores emerging concerns over safety and efficacy. Although modification of synthetic nucleic acids destined for therapeutic application is common practice to protect against nuclease degradation and to influence drug function, such modifications may also confer unexpected physicochemical and biological properties. Negatively charged oligonucleotides have a strong propensity to bind extra- and intra-cellular proteins, whereas those analogues with a neutral backbone show inefficient cellular uptake but excellent safety profiles. In addition, the potential for incorporation of chemically modified nucleic acid monomers, yielded by nuclease degradation of exogenous oligonucleotides, into biomolecules has been raised and the possibility not entirely discounted. We conclude with a commentary on the ongoing efforts to develop novel antisense compounds and enhance oligonucleotide delivery in order to further improve efficacy and accelerate implementation of antisense therapeutics for human disease

The effect of electromagnetic radiation in the mobile phone range on the behaviour of the rat

Abstract Electromagnetic radiation (EMR) is emitted from electromagnetic fields that surround power lines, household appliances and mobile phones. Research has shown that there are connections between EMR exposure and cancer and also that exposure to EMR may result in structural damage to neurons. In a study by Salford et al. (Environ Health Perspect 111:881-883, 2003) the authors demonstrated the presence of strongly stained areas in the brains of rats that were exposed to mobile phone EMR. These darker neurons were particularly prevalent in the hippocampal area of the brain. The aim of our study was to further investigate the effects of EMR. Since the hippocampus is involved in learning and memory and emotional states, we hypothesised that EMR will have a negative impact on the subject's mood and ability to learn. We subsequently performed behavioural, histological and biochemical tests on exposed and unexposed male and female rats to determine the effects of EMR on learning and memory, emotional states and corticosterone levels. We found no significant differences in the spatial memory test, and morphological assessment of the brain also yielded non-significant differences between the groups. However, in some exposed animals there were decreased locomotor activity, increased grooming and a tendency of increased basal corticosterone levels. These findings suggested that EMR exposure may lead to abnormal brain functioning

Association of a structural variant within the SQSTM1 gene with amyotrophic lateral sclerosis

Objective: As structural variations may underpin susceptibility to complex neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), the objective of this study was to investigate a structural variant (SV) within sequestosome 1 (SQSTM1). Methods: A candidate insertion/deletion variant within intron 5 of the SQSTM1 gene was identified using a previously established SV evaluation algorithm and chosen according to its subsequent theoretical effect on gene expression. The variant was systematically assessed through PCR, polyacrylamide gel fractionation, Sanger sequencing, and reverse transcriptase PCR. Results: A reliable and robust assay confirmed the polymorphic nature of this variant and that the variant may influence SQSTM1 transcript levels. In a North American cohort of patients with familial ALS (fALS) and sporadic ALS (sALS) (n = 403) and age-matched healthy controls (n = 562), we subsequently showed that the SQSTM1 variant is associated with fALS (p = 0.0036), particularly in familial superoxide dismutase 1 mutation positive patients (p = 0.0005), but not with patients with sALS (p = 0.97). Conclusions: This disease association highlights the importance and implications of further investigation into SVs that may provide new targets for cohort stratification and therapeutic development