Joint MSc programme “Applied Biochemistry: Clinical Chemistry, Biotechnology, Evaluation of Pharmaceutical Products”                      

MSc Thesis Presentation

Name: Angeliki Natsiou

Title: “Exploring collagen fiber organization and extracellular matrix architecture in atherosclerotic plaques”

Supervisor: Dr. Chrysostomi Gialeli, Researcher, University of Lund, Sweden

Date: 21/07/2025

Time: 11:00

Zoom link:

https://upatras-gr.zoom.us/j/98403186871?pwd=2V44oOA1JG15IU8PIRaHVUpq1J3YTr.1

Abstract

Atherosclerosis is the primary contributor to cardiovascular disease (CVD), the leading cause of mortality worldwide. It is initiated by endothelial dysfunction and progresses through lipid accumulation, thinning of the fibrous cap, calcification, and uncontrolled inflammation, ultimately leading to vessel narrowing and rupture. The structure, composition and turnover of the vascular extracellular matrix

(ECM) are crucial for the development of atherosclerotic plaques. Among the various ECM components, collagens are essential for maintaining plaque stability by forming the fibrous cap. As atherosclerosis progresses, collagen degradation leads to fibrous cap thinning, rendering plaques more prone to rupture. While collagen amount is important for structural integrity, research suggests that collagen type, orientation, structural organization and cross-linking are equally important for plaque stability.

The present study investigates the organization of the atherosclerotic ECM, emphasizing the spatial distribution and structural characteristics of collagen to identify patterns that contribute to plaque instability.

Histochemical staining was performed on human atherosclerotic carotid plaques to visualize collagen. ECM architecture was quantified using the FIJI macro TWOMBLI, which evaluates matrix alignment, fiber length, branching, endpoints, gaps, fractal dimension, curvature, and fiber thickness distribution. TWOMBLI analysis revealed that rupture-prone regions display a unique ECM organization pattern, characterized by lower fiber density and thickness, and a loosely packed, random ECM, where collagen fibers lack uniform orientation.

The strong correlation between TWOMBLI-derived metrics and visual histological assessment supports the utility of this method for quantifying ECM architecture. Importantly, these findings highlight the critical role of ECM organization – and specifically collagen structure –in determining plaque stability. Distinct collagen organizational patterns may serve as indicators of rupture-prone plaques, offering potential biomarkers for risk assessment.

 Angeliki Natsiou - MSc Thesis presentation