Synthetic morphogenesis to recapitulate multicellular patterns for regenerative medicine

About This Grant

Abstract The bronchial network of the lung is a tree-like structure comprising over 20 generations of dichotomous branching; yet, the signaling basis for how this elaborate network is patterned has remained an enduring mystery. This represents not only a fundamental knowledge gap in developmental biology, but also a limiting factor for developing regenerative therapies to counter lung disease. In this proposal, classic developmental biology approaches to studying lung development will be combined with a set of cutting-edge mammalian synthetic biology tools to probe the mechanism of branch patterning. This innovative approach is essential to test my central hypotheses that reaction-diffusion patterning is responsible for lung branching and that this mechanism can be tuned to control morphogenesis. Working in a state-of-the-art Biological Design Center with a team of experts in synthetic biology and lung development, I will employ a “build-to-understand” approach wherein I control cell-cell signaling through a li- brary of genetically engineered cells. In my first Aim, I will investigate the role of reciprocal FGF and Hedgehog signaling in lung branching morphogenesis in a novel model where my engineered cells are grafted onto a distal lung explant. This approach will overcome a key limitation of classic development biology approaches by enabling me to tune morphogen signaling networks in situ, and could represent a new paradigm for elucidating mechanisms of tissue morphogenesis. In my second Aim, I will take a step back from lung-specific signaling networks to examine the general principles underlying reaction-diffusion patterning of spatial patterns. Across both Aims, by manipulating cell-cell communication, I will be able to isolate the fundamental design prin- ciples that govern how activation and repression signals between cells can direct the assembly of higher-order structures. Furthermore, by decoupling specific signaling axes from their larger developmen- tal context, and by performing high-resolution, time-lapse imaging of cell fate, I will be uniquely positioned to interrogate tissue patterning mechanisms with unprecedented control. In addition to the experimental Aims, I propose a comprehensive mentoring plan to facilitate my transition to an independent faculty position. Training in mammalian synthetic biology from my co-mentor Dr. Wilson Wong and instruction in developmental lung biology from my co-mentor Dr. Darrell Kotton will combine with my prior background in biomaterials and biofabrication to give me a unique skillset for pushing forward the field of regenerative medicine. Additional consultation with my advisory committee members Dr. Chris Chen and Dr. Pulin Li will provide vital career development. My training will also involve mentoring students and leading a team of trainees in the Wong Lab, and attending and presenting my work at meetings to become an active member of the synthetic biology community. In combination, my proposed studies and career development training will equip me for success as an independent faculty member at a top-tier research institution.