Exploring the Biophysics of Aging: Chromatin Architecture Modifications in Hutchinson-Gilford Progeria Syndrome through Super Resolution Microscopy

Hutchinson-Gilford Progeria Syndrome (HGPS) represents one of the most striking forms of human premature aging disorders. Characterized by accelerated aging throughout childhood, HGPS provides a unique opportunity to study the molecular pathways underlying aging and age-related pathologies. An essential aspect in comprehending this disease is the investigation of chromatin architecture modifications, the dynamic framework crucial for controlling gene expression and preserving genomic stability. This thesis offers an in-depth biophysical investigation into the chromatin and nuclear lamina modifications associated with HGPS by bridging super-resolution microscopy and cellular biology. By exploiting super resolution microscopy’s ability to provide a detailed view of cellular structures at a molecular level, this research aims to uncover the fine aspects of chromatin organization and its aberrations in an HGPS cellular model. A particular focus in this dissertation is posed on the use of Expansion Microscopy and its capability to increase the optical resolution of conventional microscopes, allowing for the exploration of the complex interactions at the interface between nuclear lamina and chromatin. The significance of this study extends beyond the limitations of progeria. Understanding chromatin dynamics in HGPS can offer valuable insights into the underlying mechanisms of natural aging and age-related disorders. This dissertation is organized into the following sections: −Chapter 2 provides a comprehensive description of the organization of the cell nucleus, with particular emphasis on chromatin arrangement and its interaction with the nuclear lamina. −Chapter 3 presents an overview of Hutchinson-Gilford Progeria Syndrome, with a particular focus on its effects at a cellular level. −Chapter 4 provides a detailed introduction to fluorescence optical microscopy, mainly focusing on super resolution microscopy techniques. −Chapter 5 reviews expansion microscopy, specifically discussing the available protocols and validation practices. −In chapter 6, the methodology and experimental approaches employed in this study are presented and explained. −Chapter 7, which presents and discusses the results, is divided into two subsections. The first one presents the optimization of the expansion microscopy protocol. The second subsection examines the nuclear architecture modifications in our HGPS cellular model. −Chapter 8 concludes with a concise overview of the conducted experimental study. To summarize, the investigation of chromatin architecture modifications in HGPS using super resolution microscopy not only advances our comprehension of this rare yet significant disease but also contributes to expanding the knowledge in the fields of biophysics and cellular aging.