METHODOLOGICAL INNOVATIONS: 1) ENGINEERING MICROENVIRONMENTS OF CARDIAC FIBROSIS AND 2) AUGMENTING STRUCTURE INFORMATION TO DIRECTED PROTEIN EVOLUTION

Author

Lane D. Yutzy, Louisiana State University and Agricultural and Mechanical CollegeFollow

Degree

Doctor of Philosophy (PhD)

Department

Biological and Agricultural Engineering

Document Type

Dissertation

Abstract

Approximately every 40 s an individual will experience a myocardial infarction (MI) in the United States. MI can lead to permanent loss of cardiomyocytes (CMs) and increases the risk of heart disease or death. Despite immense scientific effort towards investigating therapeutics to address post-MI cardiac fibrosis, there remains a need for further investigation into the biochemical mechanisms of cardiac fibrosis and potential therapeutics. Recently the C-terminal fragment of the extracellular matrix (ECM) protein agrin (termed C-terminal agrin) was shown to induce endogenous CM proliferation and significantly reduced infarct size following ischemic injury in adult mammals. We began by demonstrating that conjugation of a peptide derived from placental growth-factor 2 (PlGF2_123-144) to C-terminal agrin confers longevity of C-terminal agrin to the fibrotic microenvironments. We then designed engineered microenvironments to mimic healthy and fibrotic cardiac tissue and demonstrated that our PlGF2_123-144-agrin conjugate has higher affinity to fibrotic microenvironments than free C-terminal agrin. To further our understanding of cell-ECM interaction, we adapted our engineered microenvironment model to allow for a multi-objective Bayesian optimization (MOBO) approach with the objective of identifying a combination of multiple ECM proteins responsible for inducing pro-fibrotic phenotypes in cardiac fibroblasts. We also described the design space and objectives of the MOBO strategy, demonstrated methodologies for controlling cell variability, and defined the endpoint of the MOBO strategy. In the final two chapters, we demonstrated two unique strategies aimed at incorporating predicted 3D protein structures into directed protein evolution approaches with the future goal of adapting these approaches to improve the structures and functionalities of laminin globular domains for cardiac regeneration.

Date

2-20-2025

Recommended Citation

Yutzy, Lane D., "METHODOLOGICAL INNOVATIONS: 1) ENGINEERING MICROENVIRONMENTS OF CARDIAC FIBROSIS AND 2) AUGMENTING STRUCTURE INFORMATION TO DIRECTED PROTEIN EVOLUTION" (2025). LSU Doctoral Dissertations. 6681.
https://repository.lsu.edu/gradschool_dissertations/6681

Committee Chair

Jangwook, Jung