Figure 7.

Myocilin is upregulated by downregulation of PrP^C. (a) PrP^C was silenced in primary human TM cells and lysates were processed as above. Probing for PrP^C shows the expected glycoforms in controls, and minimal reaction in samples treated with PrP-siRNA (lanes 1 & 2 vs. 3 & 4). Re-probing for myocilin shows significant upregulation in the absence of PrP^C (lane 1 vs 3). Exposure of control and experimental cells to dexamethasone (Dex) shows upregulation of myocilin as expected (lanes 1 & 2). However, no additive effect of dexamethasone is noted in the absence of PrP^C (lanes 3 & 4). (b) Quantification by densitometry after normalization with β-actin shows 8-fold upregulation of myocilin by dexamethasone, and ~5.3-fold upregulation in the absence of PrP^C regardless of dexamethasone. Values are mean ± SEM of the indicated n. **p < 0.01; ns: not significant. Full-length blots are included in the Supplementary Fig. S2. (c) Immunoreaction of anterior segment of PrP^+/+ and PrP^−/− mice for myocilin shows upregulation in the TM of PrP^−/− sections relative to controls (panels 1 & 2). No reaction was detected in a serial section reacted with mouse IgG followed by Alexa 546-conjugated secondary antibody (panel 3). Scale bar: 25 µm. (d) Measurement of IOP shows significant upregulation in PrP^−/− eyes relative to PrP^+/+ controls (n = 8). Values are mean ± SEM of the indicated n. **p < 0.01.