Microtubule Dynamics and the Influence of Fidgetin on Neuronal Osmosensitivity: an exploratory in vitro approach

• Grant number: 24/15494-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Biological Sciences - Biophysics - Cellular Biophysics
• Principal Investigator: Andre de Souza Mecawi
• Grantee: Fernanda Baumgratz Sette Aguilar
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

ABSTRACTHypothalamic magnocellular neurons are essential participants in the regulation of hydromineral homeostasis, secreting the neuropeptide arginine-vasopressin (AVP). Such fact occurs due to its ability to be osmosensitive - the release of AVP occurs in response to changes in the body (such as hyperosmolarity caused by intracellular dehydration); these changes lead to cell shrinkage which, in the case of magnocellular neurons, open or close ion channels, altering electrical currents and leading to the secretion of AVP (osmo-mechano-electrical transduction). It is shown in the literature that the cytoskeleton contributes to this transduction through "push" activation that leads to the opening of certain ion channels (such as TRPV1). Particularly, the microtubules of these neurons have a complex three-dimensional conformation that makes them different from other cells and even other neurons. The enzyme fidgetin, responsible for the severing of the labile domain of microtubules, has shown to be enriched (through single-cell transcriptomic analysis carried out by our research group) in magnocellular neurons of several species of mammals, primates and non-primates. Based on these evidence, the present project aims to evaluate in an exploratory manner the role of fidgetin in the conformation of neuronal microtubules and its influence on neuronal osmosensitivity in cell culture. To do so, we will evaluate the gene and protein expression of c-Fos, Avp and Fign in 4 neuronal cell lines (2 more differentiated and 2 less differentiated), in addition to analyzing the three-dimensional conformation of their microtubules - in the presence and absence of osmotic stimulus. Thus, we hope to determine the influence of fidgetin expression on microtubule remodeling in response to osmotic stimulus, as well as contribute to the understanding of its role in neuronal osmosensitivity through gene and protein expression of c-Fos and Avp.