Michael B. Butterworth Ph.D.

Our major research interest is investigating the regulation of ion transport in epithelial tissues of the kidney and airway. We have particular expertise studying the epithelial sodium channel (ENaC) and its regulation by trafficking and recycling. Studies focus on two tissues, the distal kidney nephron where upregulation of the channel is associated with volume expansion and hypertension, and human airway where ENaC hyperactivity is linked to cystic fibrosis. The main focus is understanding the cellular regulation of these sodium transporters and channels. The research could therefore be classified as cell physiology.

Our current work investigates how distal nephron transporters respond to a variety of signals including hormonal regulation via microRNAs. We have identified a subset of microRNAs that are specifically regulated by steroid hormones (aldosterone) and demonstrated that changes in microRNA expression directly alters sodium transport in the kidney. We use a range of techniques to investigate the effect of aldosterone on miRNA regulation in the kidney, and identify new protein targets that regulate ENaC. In ongoing work we have expanded this analysis to incorporate a number of hormonal signals in the kidney including vasopressin, insulin and related steroid hormones. Our lab uses a range of techniques to address these questions including RNA-Seq (microRNA deep-seq), genomic and proteomic analysis, in vitro and in vivo knockout studies, electrophysiological recordings of ion transport, biochemical and imaging approaches to study protein regulation and trafficking and mouse metabolic and diet studies.