Edith Hummler, PhD, Associate Professor
Edith Hummler was trained as biologist at the Universities of Tübingen and Göttingen, Germany, where she received her PhD in 1989. She carried out postdoctoral work with Günther Schütz at the German Cancer Research Center in Heidelberg, Germany, establishing mice deficient for the transcription factor CREB (cAMP responsive element binding protein) and for the glucocorticoid receptor.
In 1992, she joined the group of Bernard Rossier at the Department of Pharmacology and Toxicology in Lausanne, Switzerland. In 1996, she became Assistant Professor at this Department and established her own research group at the same Department. In 2003, she was additionally appointed head of the transgenic facility at the Faculty of Medicine and Biology of the University of Lausanne. Her research group has generated and analyzed several mouse models for diseases caused by the epithelial sodium channel ENaC and its regulators.
Key words: epithelial sodium channel, channel-activating proteases, serine protease inhibitors, conditional gene targeting, transgenic mouse models, sodium and potassium homeostasis, epidermal barrier function, remodeling
The research of our laboratory focuses on the molecular pharmacology and physiology of the highly amiloride-sensitive epithelial sodium channel ENaC and its regulators, the membrane-bound serine proteases, also named channel-activating proteases. The sodium channel is implicated in several pathological conditions, like hypertension, respiratory distress syndrome and in skin diseases. Genetically engineered mice and TALEN-engineered rats here help to dissect the regulation of ENaC in distinct tissues. Our laboratory focuses on two main lines of studies :
Figure 1: Implication of the amiloride-sensitive epithelial sodium channel in the control of blood pressure. We want to understand the underlying molecular and cellular mechanisms that lead to hyper- or hypoactivity of ENaC in human patients. Using Cre-loxP technology in in-vivo models, we are now able to genetically dissect ENaC-mediated sodium reabsorption along the nephron that is under the tight control of aldosterone. These findings will help to develop new targets for treatment of hypertension.
Figure 2: Role of channel activating proteases (CAPs) in epidermal remodeling and differentiation. Serine proteases represent (~2% of identified genes) carry out many physiological and cellular functions, ranging from degradation to protein processing and tissue remodeling. Their expression is tightly controlled by serine protease inhibitors and thus regulated in development and during transdifferentiation processes. Unbalanced expression of the membrane-bound serine protease CAP1/Prss8 e.g., in skin results in severe dehydration phenotypes, caused by a defective epidermal permeability barrier.