Decoding cortical Notch signaling and morphogenic instruction at cell-cell interfaces - Project Summary/Abstract – R35 Parent Grant The coordination of genetic programs and the physical organization of cells sculpt developing tissues, drive regeneration and, when dysregulated, facilitate disease. How these two processes are coordinated in space and time is poorly understood. Cell-cell interfaces are important organizing centers for morphogenic instruction. Here signals influencing gene expression that ultimately dictate cell fate decisions are integrated with changes in cell mechanics and, together, are necessary to build and maintain multicellular architectures. With an appreciation that gene regulatory networks and mechanics conspire at cell-cell interfaces to instruct morphogenic processes, an emerging challenge is to experimentally define the details of their intersectional operations in diverse morphogenic contexts. One intriguing example of cell-cell communication is the ubiquitously important Notch receptor pathway which has the intrinsic capacity to regulate both cell mechanics and gene expression, yet mechanisms of these distinct activities are unclear. As a postdoctoral fellow, the PI developed biomimetic microfluidic models of human tissues that were employed to identify several new mechanisms controlling 3D multicellular behavior operating at cell-cell and cell-extracellular matrix interfaces. The PI discovered that the highly conserved Notch family of receptors possess a previously undescribed cortical signaling function that permits Notch to connect changes in cell mechanics to transcriptional output. As an independent laboratory, the Kutys Lab has completed the first investigation into cortical Notch signaling in epithelial tissues and has identified morphogenic consequences and previously unappreciated signaling mechanisms. Over the next five years, the goal of the Kutys Lab is to continue its multidisciplinary approach of developing next generation biomimetic human tissue systems, molecular technologies, and microscopy-based methods to define the coordination of morphogenic behavior and signaling at cell adhesive interfaces. We will focus these efforts in three Areas: 1) engineering new tools to deeply understand how the cortical Notch pathway regulates signaling and adhesion mechanics in epithelia and the contexts in which it is invoked to regulate important biological processes in vitro and in vivo, 2) comprehensively defining how Notch receptor localization and activation are influenced by biophysical interactions with cell-cell adhesions and cortical actin during epithelial crowding and in endothelial cells exposed to shear stress, and 3) integrating proteomic approaches with 3D biomimetic systems to broadly profile and dissect how tissue architecture influences molecular control systems operating at cell-cell interfaces. The results of this research and the integration of the enabling technologies will contribute to the overall objectives of my research program. Together, these studies will offer fundamental insight into an important new arm of Notch signaling, how cell-cell adhesions might be dynamically regulated, and the molecular basis for how transcriptional and adhesive programs might be coordinated within complex 3D tissues.
