Cytoskeletal regulation during mitosis in the Retinal Pigment Epithelium

Objective

This proposal seeks to elucidate how the actin- and microtubule-binding motor protein Myosin7A organises the cytoskeleton during Retinal Pigment Epithelial (RPE) cell division. While the human retina has long been thought to have limited self-repair ability, new research shows it has regenerative potential, with RPE stem cells capable of undergoing cell division and repairing tissue. Unlocking the molecular mechanisms of this regeneration could revolutionise treatments for retinal degenerative diseases. However, due to the unique microenvironment and protein expression profile, the molecular mechanisms controlling RPE cell division are still unclear. Preliminary experiments suggest a previously unknown role for Myosin7A in the organisation of the mitotic spindle specific to RPE cells. In this project I aim to build upon these findings by integrating my expertise in epithelial and cytoskeletal dynamics with the host lab’s advanced ophthalmologic research pipelines. Through a bottom-up approach, I will investigate how Myosin7A influences cytoskeletal dynamics and mitotic spindle organisation, guided by the following objectives: In Objective 1, through a combination of advanced molecular techniques and high-resolution microscopy, I aim to elucidate how Myosin7A influences both microtubule and actin dynamics in human ARPE19 cells. Leveraging these findings, in Objective 2, I will systematically analyse the stages of mitosis to uncover the mechanisms underlying mitotic defects caused by Myosin7A depletion, shedding light on its role in mitotic spindle organisation. To contextualise these discoveries, in Objective 3, I will translate the results to iPSC-derived retinal organoids, providing a physiologically relevant model to better understand Myosin7A's function within the complex environment of the human retina.