Figure 6

Gene and protein expression analysis of proprotein convertase subtilisin/kexin type 9 (PCSK9) and low density lipoprotein receptor (LDLR). Quantification of (a, b) mRNA (c, d) PCSK9 protein content (pg/ ml) and (e, f) LDLR mRNA expression in human dermal fibroblasts from healthy controls (n = 4; white), PXE patients (n = 4; black), scramble siRNA-negative control (siNK, n = 4; white-striped) and ABCC6-specific siRNA-treated cells (siABCC6, n = 4; black-shaded) grown for 24 h under different cell culture conditions (+10% FCS, +10% LPDS, −FCS). Gene expression levels are normalized to reference gene expressions (ACTB, GAPDH, ß2M). Cell lysates for ELISA analysis were pooled from three biological replicates, measured in duplicates. Data are presented in arbitrary units as means with corresponding standard error. Control: PXE ratio/siABCC6: siNK ratio: ***p < 0.0001; **p < 0.003; *p < 0.05; Control 10% FCS: 10% LPDS, −FCS ratio/siNK 10% FCS: 10% LPDS, −FCS ratio: +++p < 0.0001; ++p < 0.002; +p < 0.02; PXE 10% FCS: 10% LPDS, -FCS ratio/siABCC6 10% FCS: 10% LPDS, -FCS ratio: ###p < 0.0001; #p < 0.03.