• meccanotrasduzione
• PC12
• proteine ricombinanti
• magnetogenetica
• stretch-growth
• MNP
• stimolo meccanico localizzato

“Mechanotransduction” is the conversion of mechanical stimuli into intracellular biochemical signals. It could depend on mechanosensitive elements, such as microtubules (MTs), and mechanosensitive (MS) channels. “Stretch growth” (SG) is part of this mechanism; specifically, SG has been defined as a process by which neurites elongate under mechanical stimuli.
Recently, my research group demonstrated that magnetic nanoparticles (MNPs), combined with an external static magnetic field, can apply forces to neurons and neuron-like cells, promoting neurites elongation, also characterized by low Ca2+ transients and increase in MT density.
Accordingly, the application of mechanical forces could contribute to MTs translocation and assembly; however different works pointed out a key role of MS channels in SG: some channels, such as stretch-activated channel SACs, induce Ca2+ influx inside the cell, which influence elongation by promoting or inhibiting it.
In my thesis project, I focused on understanding the role played by MS channels in SG using a nanogenetic system in PC12 cell line. The aim of the work is to modulate the intracellular localization of MNPs from non-specific localization to the plasma membrane localization, where most of the MS channels are localized and activated, to understand if these specific localizations could induce a different response in the stretched neurites. To achieve the plasma membrane localization, I synthetized MNPs, functionalized by Lck-EGFP-Mms6, a recombinant protein containing a membrane binding domain, that allows also to localize MNPs; instead MNPs functionalized by EGFP-Mms6 recombinant protein localize non-specifically. Strategy consists of internal protein-MNPs complex assembling: functionalization is obtained inside cells through transfection of plasmids coding for both recombinant reporter proteins, respectively, and the external administration of MNPs, that are also internalized inside cells.
Finally, I evaluated the effect of different MNPs localizations to the SG: a different response may be linked to a specific contribute from MTs or MS channels, respectively.