It has been demonstrated that NGF induces NO production by the induction of all three nitric oxide synthases isoforms and that, in the absence of NGF, NO itself has the ability to produce neurite outgrowth by extracellular signal regulated kinase activation through NO cGMP PKG pathway. Many authors suggest that nanotopographic guidance cues act cooperatively with NGF to regulate selleck chemicals Ruxolitinib both Inhibitors,Modulators,Libraries the generation and the orientation of neurite even under conditions of sub optimal NGF concentration. Using nanostructured substrates, Ferrari et al. showed that in PC12 cells, stimulated by various factors inclu ding NGF, neuronal polarization and contact guidance are based on a geometrical constraint of focal adhesions and that the maintenance of the established polarity is independent from NGF stimulation while strictly dependent on the topography of the substrate.

Inhibitors,Modulators,Libraries Their results suggest that different neurotrophic molecules can modulate, by the selective Inhibitors,Modulators,Libraries activation of specific mole cular pathways, contact guidance and the underlying establishment of cellular adhesions with the substrate. Therefore, the reading of the topographical Inhibitors,Modulators,Libraries guidance cues can be considered a function of the molecular dif ferentiation pathway active in the cell. Recently Lamour et al. proposed that the physical properties of the substrates can be considered as a new kind of stimulus by observing that surface free energy gradients at the nanoscale trigger neuritogenesis of PC12 cells in the absence of NGF or other inducers.

They hypothesized that PC12 cells would respond to surface properties by secreting an unknown factor that may favor neuritogenesis, however they did not provide elements Inhibitors,Modulators,Libraries to clarify the mechanisms and the proteins involved in the physical signaling. To address how the nanoscale stimuli distribution on a substrate is transduced into a signaling cascade, we stu died the differentiation of PC12 cells on nanostructured Titania substrates fabricated by nanoparticle assembling. Our bottom up approach, based on supersonic cluster beam deposition. offers the possibility to fabricate nanostructured TiO2 films resulting from a random stacking of nanoparticles and characte rized by a granularity and porosity mimicking those of ECM structures. By exploiting these properties we used ns TiO2 with tailored nanoscale roughness to grow PC12 in the pres ence and in the absence of the classical inducer of dif ferentiation NGF in order to characterize the role of nanotopography on cell differentiation.

The observed neuritogenesis triggered by the topography of ns TiO2 in the absence of NGF has been studied with particular focus on the expression of NOS and the pERK1 2 signa ling pathway. The human neuroblastoma SH SY5Y cell line, which responds to retinoic acid, selleck chem EPZ-5676 chronic NGF or brain derived neurotrophic factor.