Studying the role of microtubule network in beta-adrenergic receptors mRNA localisation in cardiomyocytes using single molecule techniques
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Author(s)
Kwan, Zoe
Type
Thesis
Abstract
The study of beta-adrenergic receptor mediated cAMP signalling has a long history in the development of our understanding of cardiac function in normal and diseased hearts. Technological advances have allowed us to look at the highly specific localisation and compartmentation of these receptors in cardiomyocytes, as well as the changes that occur during heart failure progression. Using a range of highly sensitive and specific single molecular tools, such as single molecule fluorescence in-situ hybridisation (smFISH) and nanoscale tweezers for subcellular molecule detection and sample extraction, the difference in localisation between the two major mammalian beta-adrenergic receptor subtypes, β1AR and β2AR, has been investigated. It was found that the two β-AR receptors do indeed localise differently in cardiomyocytes, both on the mRNA level as well as the protein level. The microtubule network has been revealed to be one of the crucial mechanisms governing this receptor localisation. The underlying mechanism leading to altered compartmentation in failing hearts has been examined in this work. The results suggest β-AR mRNA compartmentation, and subsequent protein redistribution, is a result of transverse tubule remodelling in failing hearts. Aiming to increase the optical resolution of the nanoscale tweezer system, this dielectrophoresis (DEP) based subcellular sampling technique was combined with scanning ion conductance microscopy (SICM), a high-resolution non-contact imaging technique. The development and application of this subcellular sampling technology with high optical resolution, namely the SICM-nanotweezers, has been reported. This novel nanoscale subcellular sampling technique was then applied onto a neonatal cardiomyocytes and sympathetic neuron co-culture model to study sympathetic synapses as a translationally active nanodomain in cardiomyocytes.
Version
Open Access
Date Issued
2023-08-25
Date Awarded
2024-02-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Edel, Joshua
Gorelik, Julia
Ivanov, Aleksandar
Publisher Department
Department of Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)