School of Biomedical Sciences cordially invites you to join the following seminar:

Speaker: Prof. Chii Jou Joe Chan, Assistant Professor of Department of Biological Sciences, Principal Investigator of Mechanobiology Institute, National University of Singapore
Talk Title: Mechanical control of mammalian folliculogenesis and its implications in ageing

Date: 27 November 2024 (Wednesday)
Time: 4:00 pm – 5:00 pm
Venue: Lecture Theatre 1, G/F, William M.W. Mong Block, 21 Sassoon Road
Host: Professor Rio Sugimura

Biography

Trained in soft matter physics, Joe Chan carried out his PhD research with Jochen Guck at the University of Cambridge, studying the mechanical and optical properties of cells and nuclei using novel biophotonic tools. He then joined the lab of Takashi Hiiragi (EMBL Heidelberg) to study the roles of fluid pressure in regulating mouse blastocyst size and cell fate specification during early embryo development (Chan, 2019, Nature). At MBI, his lab focuses on understanding how mechano-chemical signalling regulate mammalian ovarian follicle growth during development and ageing. To address these questions, the lab combines unique ex vivo reconstitution with biophysics, deep tissue imaging and computational approaches to map out tissue mechanics in follicles and ovaries. Other research themes in his lab include the study of fluid formation and mechanics during follicle development and ovulation, and the roles of macrophage mechanosensing during ovarian ageing. He has recently been awarded the Singaporean Teaching and Academic Research Talent Inauguration Award (2022).

Abstract

The maturation of functional eggs in ovarian follicles is a critical process during early mammalian development. However the underlying mechanisms driving robust follicle growth remain enigmatic. Recent studies showed that follicle growth is sensitive to mechanical environment, calling for a need to understand mechanical signalling within follicles. Here, we investigate the mechanical functions of theca cells (TCs) that encapsulate the follicles. Combining bioengineered ex vivo assays with biophysical and molecular approaches, we demonstrate that the contractile TCs exert compressive stress to tune intra-follicular pressure, thereby regulating oocyte signalling and follicle growth. We further showed that TC YAP signalling, proliferation and migration are tuned by substrate stiffness and curvature. Interestingly, spontaneous TC flow regulates selective growth of follicles in a doublet, augmenting their role in controlling follicle dynamics in ovarian setting. Finally, I will present 3D quantitative micro-elastography study that reveals spatial elasticity patterns within ovaries during ageing. Collectively, our studies highlight the importance of considering mechanobiology in understanding ovarian development and ageing.

ALL ARE WELCOME.