FIG. 2.

SCs were successfully transduced with a Tet-on GDNF LV vector. (A) A cartoon depiction of the Tet-on GDNF LV vector shows GDNF expression induced with tetracycline (or its analog doxycycline). Tetracycline binds to the reverse transcriptase activator (rtTA3), and then, together the tetracycline and rtTA3 activate the tetracycline response element (TRE) driving GDNF and DsRed expression. (B) Merged bright-field and fluorescent image is shown of Tet-on GDNF-SCs just before injection. (C) GDNF released from control vector-SCs and GDNF-SCs after doxycycline induction. (D) Average neurite length showed no difference between wild-type (WT) and control vector-SCs. Neurite length significantly increased in cultures with GDNF overexpressing SCs. Data are represented by the mean ± SEM. * denotes statistical significance from WT-SCs (p < 0.05). (E) mRNA was extracted from the distal nerve segments of GDNF-SC and control vector-SC-transplanted animals, and GDNF mRNA levels were examined. Compared to control vector-SC animals, GDNF mRNA was almost 20-fold higher in the distal nerve segment where SCs overexpressed GDNF. Dotted line marks upregulation. Color images available online at www.liebertpub.com/tea