Fig. 6

Effects on β-catenin signaling and target genes following NMP uptake in skin cells. a Study scheme. b qPCR-based gene expression analysis of CTNNB1 and CDH1. c Representative WES-images of β-catenin protein expression after acute (left) and chronic (right) NMP exposure (upper panel), and WES-based protein expression analysis of β-catenin and E-cadherin. d–e Expression and distribution of β-catenin after acute exposure to 1.0 µm NMP compared to ctrl (left panel) or chronic exposure after 2, 3, and 4 weeks (right panel) to 1.0 and NMP mix, respectively. The cell nuclei were counterstained with DAPI (blue), the cytoplasmic distribution of β-catenin was marked with a star, and the nuclear β-catenin was marked with arrowheads. Scale bars are 50 µm. f Scheme of initiation of downstream signaling by binding of Wnt proteins to a frizzled family receptor. The signal is propagated via β-catenin and ends with a change in transcription of target genes (e.g., activation of Wnt signaling; right). Inhibition of Wnt signaling activation after phosphorylation and degradation of β-catenin (left). g qPCR-based gene expression analysis of WNT1/7a. Differential expression of β-catenin target genes (e.g., LEF1, c-JUN, PPARD, GSK3β, MNMP7, VEGF). For qPCR and WES, data were normalized either to GAPDH/RLP13A or Gapdh, respectively, and untreated controls (ctrl), and presented as mean + SEM. Statistical analysis was done by unpaired, two-tailed Student's t test (n ≥ 3) with *p < 0.05, **p ≤ 0.01, and ***p ≤ 0.001