Induction of VEGF and MMP-9 expression by toll-like receptor 2/4 in human endothelial cells infected with Chlamydia pneumoniae.
Matrix metalloproteinases (MMP) are a family of host-derived enzymes involved in the turnover of extracellular matrix (ECM) molecules, and, in particular, it is demonstrated that the 92 KDa gelatinase MMP-9 is often expressed in atherosclerotic plaques by macrophages and smooth muscle cells. Recent evidence supports a role of Toll-like receptor (TLR) signaling in the development of atherosclerosis lesions. In this study, we analyzed the TLR2/TLR4 expression in HUVEC infected with C. pneumoniae and correlated it to the production of VEGF and MMP-9. The results obtained showed an increased VEGF and MMP-9 production correlated with a time-dependent increase in cellular proliferation in HUVEC infected with C. pneumoniae at a multiplicity of infection (MOI) of 2 IFU/cell. HUVEC preincubated with VEGF antibody did not release MMP-9, as detected by zymography assessment and ELISA assay. In addition, we demonstrated that TLR2/TLR4 are expressed in HUVEC infected with viable microorganisms (25&#x0025; and 17&#x0025;, respectively), while UV-inactivated microorganisms induced a lesser expression (20&#x0025; and 11&#x0025;, respectively) compared to control cells and HUVEC exposed to heat-killed bacteria showed a percentage of TLR-expressing cells similar to the control cells. In addition, the cells preincubated for 60 min with TLR2/TLR4 neutralizing antibodies showed a decrease in C. pneumonia-induced VEGF and MMP-9 production.
Department of Experimental Medicine, Section of Microbiology and Clinical Microbiology, Faculty of Medicine and Surgery, Second University of Naples, Naples, Italy.
R
R
Paolillo
M R
MR
Iovene
C
C
Romano Carratelli
A
A
Rizzo
D057134:Antibodies, Neutralizing; D049109:Cell Proliferation; D002478:Cells, Cultured; D016993:Chlamydophila pneumoniae / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity* / Q000528:radiation effects; D004797:Enzyme-Linked Immunosorbent Assay; D061307:Human Umbilical Vein Endothelial Cells / Q000201:enzymology / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000276:immunology / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000276:immunology / Q000378:metabolism*; D014466:Ultraviolet Rays; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D057134:Antibodies, Neutralizing; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D020780:Matrix Metalloproteinase 9