Karen M Ridge

My research interests focus on the intermediate filaments (IFs), which are cytoskeletal structures that are crucial for maintaining the structural integrity of cells and tissues. In general, my lab focuses on the non-mechanical roles for the IF cytoskeleton such as how IFs regulate cell migration and cell survival, and the mechanisms by which IFs are a scaffold for stress-activated kinases and adaptor proteins. We investigated whether micromechanical forces, such as shear stress and stretch, had an effect on the keratin intermediate filament (IF) network in alveolar epithelial cells. We demonstrated that these forces resulted in altered keratin IF expression in alveolar epithelial type II (ATII) cells. This work impacted the field of intermediate filament biology as it describes a mechanism by which mechanical forces and signaling molecules, such as ROS, can lead to the disassembly of the keratin IF network. More recently, we have been examining vimentin, a type III intermediate filament, that acts as a scaffold for the assembly and activation of the NLRP3 inflammasome. The existing paradigm for NOD-like receptor (NLR) signaling is that NLR proteins interact with an apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) and or a CARD domain to form a multi-protein complex called the “inflammasome”. We revealed that optimal localization and activity of the inflammasome requires the vimentin IF network, which suggests a broad biologic role for vimentin in the regulation of NLR proteins in the lung.