Roxanne Glazier

BME PhD Proposal Presentation

Friday, September 14, 2 pm

Atwood 360, Emory University

Committee Members:

Khalid Salaita, Ph.D. (Emory Chemistry, BME)

Jennifer Curtis, Ph.D. (GT, Physics)

Andrés García, Ph.D. (GT, BioE)

Adam Marcus, Ph.D. (Emory, Cancer Biology)

Phillip Santangelo, Ph.D. (GT, BME)

Probing the Role of Integrin Contractile Forces in Podosome Force Balance and Function

During diapedesis, immune cells migrate through the endothelium toward infection. While scanning to invade, they extend podosomes, which are acto-adhesive structures. It is hypothesized that these podosomes test the local stiffness. This is challenging to validate because of incomplete models of podosome mechanotransduction and a lack of suitable tools. The objective of this proposal is to develop and apply DNA probes to measure integrin forces in podosomes. The central hypothesis is that podosomes use integrins to achieve force balance and that these forces are important for podosome function, including stiffness sensing. Aim 1 contributes Molecular Tension Fluorescence Lifetime Imaging Microscopy (MT-FLIM), which uses FLIM-FRET to measure tension on supported bilayers. Intensity-based FRET tension probes (FTPs) will then be designed for imaging dynamics like diapedesis. The second aim applies MT-FLIM to a mimetic cell-cell podosome model to reveal the mechanisms of force balance. In Aim 3, FTPs will be combined with a diapedesis model to test whether podosomes exert tension for stiffness sensing in these junctions. The completion of these aims will provide novel methods to map receptor tension and will contribute a fundamental understanding of podosome mechanobiology.