Phenomenological model of transthyretin stabilization
Transthyretin is a tetrameric transport protein whose monomers, when destabilized, can misfold and form amyloid fibrils, leading to serious diseases like transthyretin amyloidosis cardiomyopathy and neuropathy. While kinetic stabilisers such as tafamidis or acoramidis are designed to prevent tetramer dissociation, clinical data show a puzzling increase in TTR levels after treatment - an effect our study seeks to investigate by exploring possible underlying mechanisms. Using a simple phenomenological model, we explore whether reduced dissociation alone accounts for this rise or if other mechanisms contribute. We propose that stabilisers may alter TTR clearance by slowing its cellular internalisation or degradation, or even by influencing its synthesis through pharmacological chaperoning. We also examine the role of monomer removal from circulation via re-association into tetramers or through other, possibly pathogenic processes. By integrating pharmacokinetic and pharmacodynamic data with experimental observations, our model provides fresh insights into TTR homeostasis and offers testable predictions for future research. This study highlights the power of simplified, hypothesis-driven models in uncovering biological mechanisms - or, at the very least, in identifying key questions that remain to be answered.