Development of a Toolkit to Investigate Endocardial Endothelial Cellular Response in Left Ventricular Outflow Tract Pathologies

Discrete subaortic stenosis (DSS) is a congenital heart disease characterized by the formation of a fibrotic membrane below the aortic valve. The underlying cellular mechanisms of this disease are currently unknown. I have created a toolkit to investigate the contributing factors of DSS membrane formation by isolating and characterizing endocardial endothelial cells (EECs) that line the left ventricular outflow tract (LVOT), modeling the elevated wall shear stress (WSS) observed in DSS patients, and creating a tunable scaffold that can be used to investigate the effect altered mechanical environments have on cells in the LVOT. With this toolkit, I cultured cells from the left ventricle of the heart, exposed the cells elevated shear stress, and performed an inhibitor study on the cells to elucidate the mechanisms of DSS membrane formation. I isolated, cultured, and characterized EECs, which are the cells that are directly exposed to the circulating blood in the left ventricle of the heart. We discovered the robust phenotype of the EECs during in vitro characterization techniques and the cells are able to maintain their endothelial phenotype across high passage numbers. I applied fluid shear stress to EECs at physiological and pathological shear rates using a cone-and-plate device. Upon characterization of the EECs after the shear experiments, it appears that shear stress triggers complex signaling pathways in EECs. I developed a 3D hydrogel scaffold with tunable mechanical properties that I seeded cells from the LVOT onto to demonstrate how the gel can be used to mimic the fibrotic conditions observed in DSS. Important insights about the cellular mechanisms of DSS have been gained from characterizing the cellular response to these environmental cues.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering

Grantor

Rice University

Year dc:date.issued

2022

Author dc:creator

• Brown, Katie N

Advisor dc:contributor.advisor

• Grande-Allen, Jane

• Endocardial Endothelial Cells
• cardiac disease model

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/114156

OAI identifier oai:identifier

oai:repository.rice.edu:1911/114156