A study examining the gene expression changes that occur in insulin-producing pancreatic cells during type 2 diabetes progression is published in Nature Metabolism this week, providing new insights that could lead to biomarkers of the disease. Type 2 diabetes occurs when pancreatic islet beta cells can no long produce enough insulin to match a patient's insulin sensitivity, but the pathogenesis of beta-cell dysfunction in the disease is unclear. To gain better understanding, a team led by researchers from the Swiss Institute of Bioinformatics and the University of Dresden performed a comprehensive multi-omics analysis of surgically sampled pancreatic islets from living human donors who range from having normal glycemic regulation to type 2 diabetes. They found that people with diabetes display remarkably more heterogeneous transcriptomic and proteomic profiles versus those without diabetes. The investigators also observed a progressive, but disharmonic, remodeling of mature beta cells over the progression to type 2 diabetes, contrary to current hypotheses of linear trajectories toward precursor or transdifferentiation stages in the disease. The team also defines the relative importance of gene co-expression modules and lipids that are associated with hemoglobin A1c levels, which could be used to develop prognostic markers.
A portable, PCR-based assay for rapid, multiplexed DNA detection with high specificity is reported in Nature Biomedical Engineering this week. While technologies exist for DNA detection, they tend to be limited either in terms of multiplexing, turnaround times, quantification accuracy, or specificity for single-nucleotide differences. In their report, scientists from Rice University describe a novel battery-powered PCR assay that is performed in a toroidal convection chamber housing a microarray of fluorescently quenched oligonucleotide probes, allowing for the quantification of multiple DNA targets with single-nucleotide discrimination. The system performs real-time detection and quantification of DNA in less than 30 minutes, they write, with a quantitative dynamic range over four logs and a limit of detection of under ten genomic DNA. "We believe that the ability of toroidal PCR to rapidly and simultaneously detect and quantify many different nucleic acid markers positions it well as a system for performing complex DNA and RNA diagnostics in settings convenient to the patient," the researchers write.
Initial results of the UK Biobank Exome Sequencing Consortium (UKB-ESC) are published in Nature Genetics this week. The UKB-ESC is a partnership between the UK Biobank (UKB) and eight biopharmaceutical companies that aims to sequence the exomes of the roughly 500,000 people participating in the UKB. In the report, consortium members present newly available exome data from 200,643 of the biobank enrollees, including around 10 million exonic variants, which represents a rich resource of rare coding variation that is particularly valuable for drug discovery.