Lauffenburger:Tharathorn Rimchala

Lauffenburger Lab

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Tharathorn (Joy) Rimchala (BE Doctoral) in collaboration with Prof. Roger Kamm, MIT see my CV or email me Research Summary: Cell Decision Model of Signaling in Endothelial Angiogenesis Angiogenic sprouting, the formation of new branch from an existing blood vessel, is a multi-cue, multi-response process. Initially a few endothelial cells lose contact with their neighbors, then acquire the ability to actively divide and to migrate into the surrounding tissue. The proliferation and migration of these angiogenic endothelial cells must be coordinated to produce appropriate vascular structures [1, 2]. Cells are exposed to different levels of various angiogenic factors, initiating diverse intracellular signals. As such, cells within a population may exhibit differential proliferation, migration and survival behaviors. Vascular endothelial growth factor A (VEGFA) and angiopoietins (Ang-1 and Ang2) are essential regulators of angiogenic sprouting since absence of these factors leads to malformation of blood vessels in vivo and embryonic lethality [3, 4, 5]. Both VEGF and Ang-1 induce cell survival, proliferation, and migration, while Ang-2 can induce either angiogenesis or vascular regression depending on the presence of VEGFA [6, 7, 8]. Signaling pathways downstream of VEGFA, Ang-1, and Ang-2 have been qualitatively associated with multiple endothelial cell responses including death, proliferation and migration [7, 8], but merely qualitative information is insufficient to effectively predict overall cell behavior in the presence of spatially and temporally varying levels of these factors during angiogenic sprouting. We are pursuing a strategy to acquire a data-driven cue-signal-response model to predict endothelial cell responses. Using human dermal microvascular cell line(hMVEC) as a model system, we measure quantitative multi-pathway signaling data (activation of key signaling proteins downstream of VEGFA, Ang-1, Ang-2) using the Luminex assay and in-cell western blotting for phosphoprotein levels. Correspondingly we measure cell proliferation, migration and survival vs. apoptosis decision using phenotypic response assays in high-throughput 96 and 384 well plate formats. To obtain differential signaling data across a broad landscape of stimulatory cues, we perform the above measurements in the presence of VEGF, Ang-1, Ang-2, and their combinations. Using regularized partial least square regression (PLSR), we will attempt to correlate the measured signaling data to the measured cellular responses to obtain a set of proteins whose changes in phosphorylation are predictive of proliferation, migration, and survival vs. apoptosis decision [11, 12].