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DTSTAMP:20260829T145910Z
LAST-MODIFIED:20180720T194331Z
DTSTART:20180724T180000Z
DTEND:20180724T190000Z
UID:event2002@bu.edu
URL:http://physics.bu.edu/internal/events/show/2002
SUMMARY:"Topological transitions of epithelial tissues"
DESCRIPTION:Featuring Keisuke Ishihara\, Max Planck Institute of Molecular 
	Cell Biology and Genetics\, Dresden\, & Max Planck Institute for the Physic
	s of Complex Systems\, Dresden\n\nPart of the Biophysics Seminars.\n\nThe e
	pithelium is a fundamental tissue architecture that lines the outer surface
	s of many organs and inner cavities within them. While past studies have de
	monstrated how local differences in cell mechanical properties induce epith
	elial folding\, the question of epithelial topology has not been addressed.
	 What are the physical conditions that determine whether an epithelium rema
	ins well connected\, or transitions to a phase where the tissue divides int
	o multiple\, topologically distinct epithelia? I have developed a novel in 
	vitro assay to address how developmental cues\, cell biological mechanisms\
	, and tissue mechanics interact to govern the topological transition of epi
	thelial tissues. In this assay\, free-floating aggregates of ~1000 mouse em
	bryonic stem cells are differentiated into the neural lineage in medium sup
	plemented with extracellular. Within 4 days\, a continuous apical membrane 
	domain is observed in the interior of the tissue as a result of collective 
	cell polarization and epithelialization. Treatment with retinoic acid induc
	es a change in epithelial topology where the apical membrane domain splits 
	up into multiple spherical structures\, which is explained as a multiple cy
	st phenotype. My preliminary results support a scenario where reduced lysop
	hosphatic acid signaling\, and consequently\, reduced PODXL protein levels 
	to be downstream of retinoic acid. PODXL is an apical membrane protein with
	 a negatively charged extracellular domain\, which I hypothesize to increas
	e apical surface area. Based on these findings\, I propose that epithelial 
	topology can predicted in a physical framework similar to surfactant self-a
	ssembly.
LOCATION:SCI 352\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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