Figure 12. ER stress signaling plays a key role in facilitating autophagy and HDAC6 protein degradation. (A) HCN2 cells were transfected with a scrambled siRNA or with an siRNA molecule to knock down the expression of eIF2α. After 24h, cells were treated with vehicle control, AR12 (2 μM), neratinib (50 nM) or the drugs in combination for 6h. Cells were fixed in place and immunostaining performed to determine the expression of HDAC6, LAMP2, p62 and ERK2. (n = 3 +/-SD) * p < 0.05 less than vehicle control; ** p < 0.05 less than either of the individual treatments; ¶ p < 0.05 greater than corresponding value in siSCR cells. (B) BV2 cells were transfected with a scrambled siRNA or with an siRNA molecule to knock down the expression of eIF2α. After 24h, cells were treated with vehicle control, AR12 (2 μM), neratinib (50 nM) or the drugs in combination for 6h. Cells were fixed in place and immunostaining performed to determine the expression of HDAC6, LAMP2, p62 and ERK2. (n = 3 +/-SD) * p < 0.05 less than vehicle control; ** p < 0.05 less than either of the individual treatments; ¶ p < 0.05 greater than corresponding value in siSCR cells.