Tight junctions and tissue mechanics as sensors and executers of heart regeneration

Introduction

One of the most fascinating aspects of salamander regeneration is the level of precision at which restoration of complex structures occurs. How the recovery of form and function is sensed at a cellular level leading to appropriate termination of regenerative programs remains largely unknown. This is partly due to technical challenges of studying cellular events at a high resolution during regeneration and establishing a constitutive link between cell behavior, tissue architecture, and function.

Proposed Approach

Here, I propose taking an interdisciplinary approach that combines gene editing, deep-tissue imaging, force measurements, and spatial -omics to overcome these barriers. My goal is to gain a holistic understanding of regeneration by integrating molecular, cellular, mechanical, and functional parameters.

Specific Aims

Specifically, I aim to explore the role of tight junctions and mechanical cues in sensing and relaying macroscale information to adapt cellular events as the regeneration unfolds. We will utilize the newt Pleurodeles waltl and heart regeneration as an ideally suited regeneration context where I recently showed that the injury response by the epithelial-like covering called epicardium and the dedifferentiating cardiomyocytes are closely coordinated to replenish the lost muscle.

Methodology

By combining long-term intravital cell tracking, mechanical characterization, and ultrasound imaging with tight junction manipulations and mechanical perturbations, we will:

1. Define cell dynamics and regenerative state transitions.
2. Test whether unique expansion in the tight junction protein Claudin-6 sequence that extends its N-terminus is protective against overproliferation.
3. Map the physical properties controlling the termination of regenerative programs.

Expected Outcomes

Our results will identify mechanisms underlying the tight control of regeneration and bring new insights into the function of Claudins that are frequently dysregulated in cancer, opening new venues in regenerative medicine and cancer research.