Figure 1.

Polycystin-1 and polycystin-2 are required for the anabolic response to strain. Immortalized murine chondrocytes were treated with siRNA for pkd1 and pkd2 to deplete Polycystin-1 and Polycystin-2 expression and a negative control siRNA (-ve). Cells were subjected to 10% cyclic tensile strain (CTS) for 1 h at 0.33 Hz. Changes in gene expression for (A) aggrecan (acan) and (B) collagen type II (col2a) were quantified by qRT-PCR. Samples were normalized to GAPDH and expressed as a fold change relative to the -ve control (Statistics: two-way ANOVA with Tukey’s multiple comparisons test, n = 4). Significance is displayed relative to the no CTS -ve control as * = p < 0.05 and ** = p < 0.01, whereas $ denotes significance relative to the CTS -ve siRNA ctrl group where $$ = p < 0.01 and $$$ = p < 0.001.