H2B-mCherry (red) labels nuclei while green marks expression of Isl1-GFP (green) in reprogramming cells over 36 hrs.
Hyperproliferation and hypertranscription drive rapid, robust conversion yet are often mutually inhibitory. These observations raise additional questions about the precise mechanisms by which hyperproliferation and hypertranscription enhance transitions in cellular state, which may refine our understanding of both synthetic and pathological cellular transformations (e.g. reprogramming, cancer).
DESIGNING SOFTWARE TO MATCH HARDWARE
Scaling circuit output to match cellular capacity
Tradeoffs between transcription and replication limit cellular reprogramming, with excessive transcription limiting necessary cellular division. To effectively balance these tradeoffs, our lab constructs control systems to tailor expression of reprogramming factors to cellular capacity.
MEASURING TRANSITION SPEED
Characterizing the dynamics of proliferation-mediated transitions between cell states
By examining the process of cellular decision-making in the synthetic context of reprogramming, we examine the contribution of developmentally-entangled systems-level phenomena (e.g. transcriptional activity, proliferation) to cell state switching. State transitions from one cell fate to another represent transitions in large transcriptional networks that may be approximated by transitions in small transcriptional networks (e.g. a bistable switch), which can be more easily measured, modified, and modeled. Using a synthetic circuit as a probe, my lab will characterize how direct conversion and hyperproliferation affect the dynamics of transitions within a bistable circuit.
TOWARDS TISSUE REGENERATION
Developing tools and insight to enable in vivo reprogramming.
Tissue regeneration to replace damaged or diseased cells endures as a prime objective in regenerative medicine. With improved in vivo delivery vehicles via adeno-associated virus (AAVs), limitations in conversion efficiency in human cells remain the primary barrier to in vivo reprogramming therapies. Comparison of mouse and human reprogramming suggests mechanisms that limit the human system. Additionally, translating improved vectors to promote in vivo reprogramming will be an important long-term goal of my lab.