G₁ Cell Cycle Arrest Is Induced by the Fourth Extracellular Loop of Meningococcal PorA in Epithelial and Endothelial Cells

Figure 6

Infection of HBMECs with N. meningitidis MC58 and ΔPorA-Loop4 causes perturbations in p-CDK4 (Thr172) and Cyclin D1 expression. HBMECs were left uninfected (control) or infected with wild-type N. meningitidis MC58 or its isogenic derivative MC58 ΔPorA-Loop4 at MOI 500 for 8 h, 37°C, and 5% CO₂. Cells were lysed for immunoblotting and densitometry analysis of p-CDK4 (Thr172) (a) and Cyclin D1 (b) protein expression. Alpha actinin was used to normalize protein loading. The figure shows a representative blot with lanes from different areas of the same membrane (left). Band intensities were quantified by densitometric analysis using Image J and normalized to alpha actinin (right). Immunoblotting was each performed in three independent experiments. Significant difference to the untreated (, , and , ns: not significant), ANOVA (with Tukey’s test applied post hoc).

(a)

(b)