Fig. 4

MPA treatment induces nucleolar stress in DMSC. a Confocal microscopy of nucleophosmin/B23 staining (arrows) in DMSC treated for 48 h with MPA showed reduced numbers and sizes of nucleoli (asterisks) when compared to untreated cells. Actinomycin D (AD) treatment for 18 h served as a positive control of disorganization of nucleoli. Nuclei were counterstained with DAPI. The quantification of total fluorescence by ImageJ was expressed as the corrected total cell fluorescence (CTCF) (***P ≥ 0.001). b Expression level of the ribosomal precursor 45S measured by quantitative PCR. MPA treatment downregulated transcription of the gene for 45S ribosomal precursor. Data were normalized with respect to β-actin gene expression and results are shown as relative expression to untreated cells (control) calculated by the 2^_ddCt method. As a positive control of nucleolar stress, actinomycin D (AD) was used (**P ≥ 0.01****P ≥ 0.0001)