The underrepresentation of non-Europeans in human genetic studies so far has limited the diversity of individuals in genomic datasets and led to reduced medical relevance for a large proportion of the world’s population. Population-specific reference genome datasets as well as genome-wide association studies in diverse populations are needed to address this issue. Here we describe the pilot phase of the GenomeAsia 100K Project. This includes a whole-genome sequencing reference dataset from 1,739 individuals of 219 population groups and 64 countries across Asia. We catalogue genetic variation, population structure, disease associations and founder effects. We also explore the use of this dataset in imputation, to facilitate genetic studies in populations across Asia and worldwide.
Purpose.: The present study was designed to understand the role of inflammatory cytokines secreted by corneal epithelial cells in keratoconus (KC) and the response to treatment with cyclosporine A (CyA). Methods.: The study involved 129 Indian KC patients clinically graded according to Amsler-Krumeich classification and 20 healthy, nonectatic subjects as controls. Tear levels of matrix metalloproteinase-9 (MMP9), interleukin-6 (IL6), and tumor necrosis factor-α (TNFα) were measured using ELISA kits. Gene expression was measured by qPCR in corneal epithelial cells obtained by debridement from subjects undergoing ocular surface surgeries. In addition, epithelial cells were stimulated with TNFα and treated with CyA to study its role on MMP9 expression. Finally, 20 KC patients (27 eyes) with inflammatory symptoms were treated with topical CyA application. Results.: We observed that MMP9, TNFα, and IL6 levels were strongly upregulated at the mRNA level in KC patient epithelia. Similarly, tears collected from KC patients exhibited high levels of MMP9 and IL6 protein. Cyclosporine A treatment significantly reduced the mRNA expression levels of IL6 and TNFα in both short- and long-term treatments; however, it reduced MMP9 levels only in long-term treatment in cultured corneal epithelial cells. Subsequent treatment of KC patients with CyA for approximately 6 months reduced tear MMP9 levels and led to local reduction in corneal curvatures as determined by corneal topography maps. Conclusions.: The data indicate that corneal epithelium contributes to elevated MMP9 and inflammatory cytokine expression in tears of KC patients. Cyclosporine A treatment reduced MMP9 and inflammatory cytokine levels in an in vitro inflammation model system. In KC patients, CyA treatment reduced MMP9 levels measured in tears with concomitant arrest of disease progression. Therefore, CyA might be a novel treatment strategy in KC patients but requires additional evaluation in larger cohorts. (ClinicalTrials.gov number, NCT01746823.)
Although adeno-associated virus (AAV)-mediated gene therapy has been hindered by the small viral packaging capacity of the vector, trans-splicing AAV vectors are able to package twice the size of the vector genome. Unfortunately, the efficiency of current trans-splicing vectors is very low. Here we show that rational design of the gene splitting site has a profound influence on trans-splicing vector-mediated gene expression. Using mRNA accumulation as a guide, we generated a set of efficient trans-splicing vectors and achieved widespread expression of the 6-kb ΔH2-R19 mini-dystrophin gene in skeletal muscle of mdx mice, a model for Duchenne muscular dystrophy. The dystrophic phenotype was ameliorated in both adult and aged mice. This demonstrates the use of trans-splicing vectors to efficiently express a large therapeutic structural protein. This strategy should be applicable to other large therapeutic genes or large transcription regulatory elements.