We are gald to announce the upcoming talk given by Daniel Seeler in the Oberseminar "Geometrie und Visualisierung" (Geometry and Visualization).

Title
Development of a geometric blood vessel model to quantify morphological changes of endothelial cells in 3D

Affiliation
Institut für Mathematik der Universität Potsdam, Potsdam, Deutschland

Date, Time and Place
08.09.2022, 4:15 pm, Arnimallee 6 - Room 108/109

Abstract

Endothelial cells (ECs) lining the blood vessel interior perceive the magnitude and direction of blood flow. In response to strong blood flow ECs elongate and align in flow direction. These cell morphological changes lead to changes in vessel diameter and, subsequently, blood flow dynamics. To better understand these coupled processes, we developed a geometric model linking EC shape and blood vessel geometry and used it to quantify morphometric measures of ECs in 3D.
We obtained EC contours in the dorsal aorta of zebrafish embryos at 48 hours post fertilization (hpf) and 72hpf by manually annotating 3D data points onto an EC-specific fluorescent marker. Then, we locally estimated cross-sectional shapes along the vessel axis. Feasibility and locality of the estimation was ensured by considering the projection errors of all points in proximity to the cross-section with Gaussian weights decaying with distance. To improve the estimation in case of outliers and data sparsity, we (1) chose the width of the weight function adaptive in space and (2) constrained the deviation of the local cross-sectional shape’s parameters from the mean shape’s parameters. We interpolated between the estimated cross-sectional shapes by triangulation. Using the triangulated surface we were able to quantify the increase of EC elongation in flow direction between 48hpf and 72hpf.