• nanogratings
• dopamine
• mechanotransduction
• cAMP
• neurite pathfinding
• contact guidance

The aim of this thesis is the study of the correlation between mechanostransduction and dopamine (DA) signaling, by using an in vitro human neuronal model based on human neuroblastoma SH-SY5Y cells (SH-SY5Ys).
SH-SY5Ys were cultured on two kinds of substrate: a control flat surface (FLAT) and anisotropic substrates characterized by imprinted nanopatternes (i.e. nanogratings -NGs-). In order to obtain dopaminergic neuronal cells, SH-SY5Ys were differentiated through a 10 days differentiation protocol based on retinoic acid (RA) and brain derived neurotrophic factor (BDNF). Bright field imaging showed a different organization of differentiated SH-SY5Ys depending on the substrate topography. On NGs the cells acquired a clear orientation following the NG lines. This morphological orientation was correlated with cytoskeleton organization, that we quantitatively evaluated by immunocytochemistry and fluorescence confocal microscopy techniques.
The effect on cell topography sensing of specific drugs acting on dopaminergic system was then investigated. Specifically we administrated DA and its precursor L-DOPA. The treatment with these dopaminergic agonists led to worse SH-SY5Ys alignment and cytoskeleton organization upon differentiation. These data suggest that the treatment with DA and L-DOPA can interfere with cell mechanotransduction.
Finally, by means of real-time PCR, the variations of mRNA levels of the principal molecules involved in DA signaling (D1R and D2R and the enzyme TH) in cells differentiating on NGs was measured with respect to those cells seeded on FLAT. We found upregulation of D1 and D2 receptors genes and unaffected TH transcription, indicating that topographical stimuli can modify neuronal response to DA.