PhD Qualifying Examination

Mechanical impact of apoptotic cell extrusion in neighbouring tissue

Speaker          :   YOW Ying Ming, Ivan (Graduate Student, MBI, NUS)
Date                :   22 Mar 2017, Wednesday
Time                :   2pm
Venue             :   NUS, E3-06-10

Supervisor(s)  :  Asst. Prof TOYAMA Yusuke

Abstract: Apoptotic cell extrusion is an important mechanical process that forcibly pushes a dying cell out of a tissue monolayer by forces exerted from its neighbouring cells. Studies have shown forces from apoptotic cell extrusion are required for cell-sheet fusion in Drosophila embryos while modulation of tissue tension can regulate apoptotic cell extrusion. As such, mechanical forces may be involved in the regulation of cell extrusion. However, little is known how tension is regulated after cell extrusion and there has not been any report on how changes in tension can regulate the biochemical cascade in the neighbours of dying cell that may provide a feedback to regulate the cell extrusion process.

In this proposal, we will first probe how tissue stress changes upon apoptotic cell extrusion (Aim 1). To understand how neighbouring cells may respond to signals from the dying cells, we will elucidate how neighbouring cells respond biochemically to apoptosis through mechanics (Aim 2). Mechanosensitive molecules that exhibit nuclear translocation will first be explored and eventually we want to know whether this nuclear translocation is regulated through mechanical force. Another interesting, unanswered question is what happens to neighbouring cells’ actin dynamics after completion of cell extrusion (Aim 3). We hypothesise that the changes in actin dynamics may be coupled with the changes in mechanical forces These may address the longstanding question of how a dying cell ‘sends’ signal to the neighbouring cells, of which one will undergo compensatory cell division to maintain tissue homeostasis.

With these open questions in the field of research, the research question I propose is ‘How apoptosis mechanically influence neighbouring cells’.

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