Neurodegenerative diseases such as Huntington's Disease (HD) have a significant impact on healthcare accessibility and costs. A fatal genetic condition, characterized by the progressive loss of striat Show more
Neurodegenerative diseases such as Huntington's Disease (HD) have a significant impact on healthcare accessibility and costs. A fatal genetic condition, characterized by the progressive loss of striatal neurons, HD is hindered by the lack of endogenous repair in the adult brain. Recent efforts toward protecting neural circuits through neurotrophic support using brain-derived neurotrophic factor (BDNF) have been suboptimal due to the protein's short half-life and limited diffusion. Addressing this, adeno-associated viral vectors (AAV) can be employed as a delivery tool to spatially transduce cells, enabling the localised production of BDNF with consequential neuron protection and/or plasticity, yet present their own constraints. To overcome these known challenges of AAV gene delivery, an injectable, physiologically stable hydrogel-mimic of the brain's extracellular matrix was fabricated to encapsulate the AAVs. This smart system both shielded and constrained the AAV; optimising transfection and therefore elevated and sustained BDNF presentation at the target site. Here, we achieved high neuroprotection using AAVDJ-BDNF delivered through a hydrogel formed via self-assembling peptide nanoscaffolds. These findings support the notion that the spatiotemporal release of BDNF to striatal neurons, facilitated by engineered biomaterial delivery systems, demonstrates tremendous promise by enhancing the efficacy of gene therapy targeted at slowing neurodegenerative disease progression. Show less
Epigenetic modifications such as DNA methylation play a key role in gene regulation and disease susceptibility. However, little is known about the genome-wide frequency, localization, and function of Show more
Epigenetic modifications such as DNA methylation play a key role in gene regulation and disease susceptibility. However, little is known about the genome-wide frequency, localization, and function of methylation variation and how it is regulated by genetic and environmental factors. We utilized the Multiple Tissue Human Expression Resource (MuTHER) and generated Illumina 450K adipose methylome data from 648 twins. We found that individual CpGs had low variance and that variability was suppressed in promoters. We noted that DNA methylation variation was highly heritable (h(2)median = 0.34) and that shared environmental effects correlated with metabolic phenotype-associated CpGs. Analysis of methylation quantitative-trait loci (metQTL) revealed that 28% of CpGs were associated with nearby SNPs, and when overlapping them with adipose expression quantitative-trait loci (eQTL) from the same individuals, we found that 6% of the loci played a role in regulating both gene expression and DNA methylation. These associations were bidirectional, but there were pronounced negative associations for promoter CpGs. Integration of metQTL with adipose reference epigenomes and disease associations revealed significant enrichment of metQTL overlapping metabolic-trait or disease loci in enhancers (the strongest effects were for high-density lipoprotein cholesterol and body mass index [BMI]). We followed up with the BMI SNP rs713586, a cg01884057 metQTL that overlaps an enhancer upstream of ADCY3, and used bisulphite sequencing to refine this region. Our results showed widespread population invariability yet sequence dependence on adipose DNA methylation but that incorporating maps of regulatory elements aid in linking CpG variation to gene regulation and disease risk in a tissue-dependent manner. Show less