Figure 7. Endogenous Zhangfei suppresses the activation of UPR genes in rat peripheral neurons.

Primary rat dorsal root neurons were transfected with plasmids expressing either control siRNA or siRNA against Zhangfei (siRNA-ZF). The next day cells were treated with DMSO or thapsigargin and 4hr later RNA was harvested for qRT-PCR analysis using primers designed to amplify Xbp1s, CHOP, GRP78, Xbp1us (A) or Zhangfei (B). A. Fold increases in RNA between DMSO and thapsigargin treated samples comparing siRNA-ZF (black bars) and siRNA control (white bars) expressing cells. B. Effect of si-ZF on transcripts levels of endogenous Zhangfei. Results are expressed as 1/Ct. Columns represent averages of triplicate samples with bars as standard deviation from the mean. C. Suppression of endogenous Zhangfei increases Xbp1s, Grp78 and HERP proteins. Lysates of neurons transfected with either siRNA-ZF or siRNA-control were analyzed by immunoblotting using antibodies against UPR-related proteins. Bands on immunoblots of the left were scanned and band densities relative to the internal standard GAPDH are on the graph on the right. D. Transfection efficiency test of siRNA. Primary rat dorsal root neurons were transfected at a final concentration of 10 nM with the TYE 563 DS Transfection Control duplex, and were imaged 24 hours post transfection (Red: marked siRNA; blue: nuclear).