Figure 4From: Integrin α5β1-fimbriae binding and actin rearrangement are essential for Porphyromonas gingivalis invasion of osteoblasts and subsequent activation of the JNK pathwayP. gingivalis initially suppresses but later promotes osteoblast apoptosis. A. Western blot demonstrating the initial weak (day 1–7) but later more intense (day 14–21) cleaved caspase-3 expression in P. gingivalis-infected osteoblasts compared with uninfected control cells. Actin is the loading control. B. Quantitative densitometric analysis of cleaved caspase-3 by western blotting. Abbreviations: Ctrl, non-infected osteoblasts; PG, P. gingivalis infected osteoblasts; D, day. C. TUNEL assay showing significantly less apoptotic osteoblasts from day 1–7, followed by significantly more apoptotic osteoblasts from day 14–21 in P. gingivalis-infected cultures compared with uninfected control cells. Arrows denote condensed, blue-stained, apoptotic osteoblast nuclei. Nuclease treatment and exclusion of TdT enzyme were used as positive and negative controls, respectively. D. Quantitative analysis of the TUNEL assay data. Abbreviations: (+) Ctrl, nuclease treated, used as positive technique control; (-) Ctrl, exclusion of TdT enzyme, used as negative technique control; CT, uninfected osteoblasts; PG, P. gingivalis infected osteoblasts; D, day. Scale bar = 20 μm. * denotes P < 0.05.Back to article page