Figure 7.

Podoplanin: a potential new player in the NGF/TrkA signaling pathway. (a) Real-time monitoring for potential human podoplanin and human NGF macromolecular interactions using SPR data obtained in a BiaCore apparatus showed a relatively high-affinity binding of recombinant NGF to immobilized podoplanin protein, as expressed in relative binding units on the y axis vs time. No binding was observed when a control GDF-8 recombinant protein was used even at concentrations five times higher than those used for the NGF assay. A heparin-based solution was used as a dissociation buffer. (b) No differences in the basal levels of total Ezrin or p-Ezrin (c) were observed between wild-type and podoplanin−/− mice hippocampal neurons. However, primary-cultured hippocampal neurons presented with comparatively lower levels of p-Ezrin upon NGF stimulation (50 ng/mL, 20 min) (d). Comparably, no differences in the levels of TrkA were observed under basal untreated conditions (e) but reduced levels were found in neurons from podoplanin−/− after NGF treatment (50 ng/mL, 2 h) (f). (g) Levels of CREB were also enhanced upon NGF stimulation in neurons from wild-type mice whereas CREB levels did not alter in response to NGF treatment in podoplanin−/− cultured neurons. Data are displayed as mean ± SEM. ns (p > 0.05), *(p ≤ 0.05), **(p ≤ 0.01), ***(p ≤ 0.001).