C. trachomatis infection reduces Drp1 protein levels upon infection and is affected by artificial modulation of Drp1 levels. (A) Quantification of qRT-PCR for p53 and Drp1 mRNA levels in noninfected and C. trachomatis (C.tr)–infected HUVECs for 12, 24, and 36 h. Fold change of Drp1 (± SD) at 24 h, 0.6 ± 0.30; and 36 h, 0.325 ± 0.10 (n = 6). (B) Immunoblot of HUVECs transfected with vector control or pcDNA-Drp1 overexpression vector and infected with C. trachomatis for 12, 24, and 36 h. Blots were probed with antibodies against Drp1, chlamydial heat shock protein 60 (cHSP60), and actin. (C) Immunoblot of hFIMB cells infected with C. trachomatis for 12, 24, and 36 h. Blots were probed with antibodies against Drp1, cHSP60, and actin. (D) Immunoblot of HeLa cells transfected with siRNA negative control and Drp1 siRNA infected with C. trachomatis for 12, 24, and 36 h. Blots were probed with antibodies against Drp1, cHSP60, and actin. (E) Immunoblot of HUVECs transfected with siRNA negative control or siRNA against Drp1 for 24 h and infected with C. trachomatis for 18 h. Blots were probed with antibodies against Drp1, cHSP60, and actin. (F) Immunoblot of infectivity assays of 36 h of primary C. trachomatis infection in HUVECs transfected with siRNA negative control, pcDNA-Drp1 overexpression vector, or Drp1 siRNA pool. All data represents mean ± SD. Asterisks denote significance by Student’s t test. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, nonsignificant.