Figure 5

HO-1 mediates cell adhesion via PXDN in BeWo choriocarcinoma cells via PXDN. (A) Control-infected (LMP) or miHO-1 (miHO-1) infected BeWo cells were seeded on fibronectin (FN), collagen type I (Col I), laminin (Ln) or tissue culture plastic (TC) and assayed for adhesion as described in Materials&Methods. Photographs were taken at a 40x magnification. (B) The absorbance of fixed and crystal-violet stained cells at 550 nm of ctrl (LMP) infected cells were arbitrarily set to 100% in each experiment. Note that HO-1 deficient BeWo cells (miHO-1) became less adherent than LMP cells expressing HO-1 endogenously (*P < 0.05 vs LMP cells). PXDN knocked down in BeWo LMP and miHO-1 cells after transient transfection with a control (siCtrl) or PXDN-specific (siPXDN) siRNA, as determined by real-time PCR (C) and western blotting (D). β-actin indicates equal loading. Effect of PXDN-knockdown on cell adhesion to fibronectin (E) or laminin (F) in control-infected (LMP) or miHO-1 (miHO-1) infected BeWo cells. For comparison, OD-values of ctrl (LMP) infected cells were arbitrarily set to 100% in each experiment. Note that HO-1 expressing cells (LMP), but not HO-1 deficient cells (miHO-1) became less adherent following PXDN-knockdown (*P < 0.05 vs siCtrl-treated LMP cells). (G) Effect of ectopic PXDN expression on cell adhesion of miHO1 BeWo cells. For comparison, OD-values of cells transfected with an empty control plasmid (pCDNA) were arbitrarily set to 100% in each experiment. Note that PXDN overexpressing cells (pPXDN), but not mock-transfected cells (pcDNA) became more adherent (*P < 0.05 vs pcDNA treatment).