FIGURE 5.

Rho kinase (ROCK) inhibitors suppress rescue upon MT depolymerization. A, mutant htt cells were treated with a dilution series of three ROCK inhibitors Y-27632 (Y), hydroxyfasudil (HSA), or H1152 alone or in combination with Pdx (400 nm) or BOC-D-fmk (BOC, 50 μm) and cell viability was determined by a trypan blue dye exclusion assay. The increase in cell viability relative to DMSO-treated cells was determined after 2 days in SDM. Data are the mean ± S.D. of an experiment performed in duplicate. (*, p < 0.05, Student's t test). B, mutant htt cells were treated with DMSO, Pdx (400 nm), or Pdx (400 nm) in combination with individual ROCK inhibitors (Y-27632, 40 μm; hydroxyfasudil (HSA), 75 μm; H1152, 20 μm) and levels of CTGF, phosphorylated and total ERK were determined by Western blotting at the indicated time points for Y-27632, or 6 h after treatment, for hydroxyfasudil and H1152 treatments. Tubulin was a loading control. The experiments are representative of at least two independent experiments for each treatment. pERK and ERK were quantitated using Image J (NIH) and the level of pERK was normalized to ERK and the 6-h time in SDM was set as 1 in each treatment. pERK levels relative to the 6-h time point are provided below the blots. C, mutant htt cells were treated with DMSO, Pdx (400 nm), or Pdx (400 nm) + Y-27632 (40 μm) and the tubulin network was visualized by immunofluorescence 6 h after treatment.