Effects of Chlamydia pneumoniae infection on adhesion and migration of vascular smooth muscle cells

AIM: To investigate the effects of Chlamydia pneumoniae (C.pn) infection on the adhesion and migration of vascular smooth muscle cells (VSMCs). METHODS: Primary VSMCs, isolated from the aorta of SD rats, was infected with C.pn after the culture and propagation of C.pn in the HEp-2 cells. The morphological characteristics of C.pn inclusions in VSMCs were examined under the fluorescence microscope with acridine orange (AO) staining. The specific DNA fragment of C.pn was identified by polymerase chain reaction (PCR). Cell adhesion assay was performed to investigate the effect of C.pn infection on the adhesion of VSMCs to collagen I. Wound-healing assay and Transwell assay were performed to detect the effects of C.pn infection on VSMCs migration. RESULTS: The C.pn inclusions and infection spots were observed in VSMCs under fluorescence microscope with AO staining. The inclusions were larger than infection spots in volume, but were much lower in count. A 437 bp-specific fragment of C.pn DNA was detected in C.pn-infected VSMCs by PCR. In the cell adhesion assay, the absorbance values in C.pn infection group were far higher than those in control group 2 h after infection (P<0.01). The cell adhesion ratio in C.pn infection group was 134.38%. The migration distance of VSMCs infected with C.pn was significantly longer than that of the control cells 24 h after infection by a wound-healing assay (P<0.05). More migratory VSMCs infected with C.pn for 24 h were found in a Transwell assay than those in control group (P<0.01). CONCLUSION: C.pn infection significantly promotes the adhesion and migration of VSMCs.