Skip to main content
. Author manuscript; available in PMC: 2016 Jan 15.
Published in final edited form as: Cell. 2015 Jan 15;160(0):161–176. doi: 10.1016/j.cell.2014.11.053

Figure 2. MKK4 functions as the predominant MAPKK assisted by MKK7 in axon degeneration following traumatic injury. See also Figure S3 and Table S1.

Figure 2

(A to C) MKK4 regulates degeneration of injured sensory axons. Cultures of embryonic DRG neurons were subjected to lentiviral-shRNA knockdown of MKK4. Efficiency of lentiviral-shRNAs was examined by immunoblot analysis of axonal proteins harvested from each condition (A). Degeneration of axons transduced with the two most efficient lentiviral-shRNAs was visualized by immunostaining at indicated time points after axotomy (B), and degeneration was quantified (C), n=3 for each condition. (D and E) MKK4 functions with MKK7 to regulate degeneration of injured RGC axons in vivo. RGCs of the mice with indicated genotypes were transduced with Cre/scrambled-shRNA or Cre/MKK7-shRNA virus. Ai14 represents the Rosa26-CAG-LSL-TdTomato reporter. Degeneration of TdTomato-positive axons was visualized at indicated time points after optic nerve crush (D), and degeneration was quantified (E), n=4 for each condition. (F and G) MKK4 / MKK7 regulate degeneration of injured cortical axons. Cultures of embryonic cortical neurons with indicated genotypes were transduced with lentivirus expressing Cre together with scrambled-shRNA or MKK7-shRNA. Axon degeneration at indicated time points following axotomy was visualized by immunostaining (F), and degeneration was quantified (G), n=3 for each condition. Values are presented as mean ± SEM; *, p < 0.01.