The -1562C/T MMP-9 promoter polymorphism does not predict MMP-9 expression levels or invasive capacity in saphenous vein smooth muscle cells cultured from different patients.
Matrix metalloproteinase-9 (MMP-9) is an important regulator of vascular smooth muscle cell (SMC) invasion and proliferation. The T allele of the -1562C/T MMP-9 promoter polymorphism reportedly confers increased MMP-9 promoter activity, plasma MMP-9 levels and susceptibility to vascular pathologies. The aim of this study was to determine whether the MMP-9 -1562C/T polymorphism directly influences endogenous MMP-9 expression levels in saphenous vein (SV) SMC cultured from patients with different genotypes. Genotyping of 408 patients revealed -1562C/T genotype frequencies of 73.3% CC, 25.0% CT and 1.7% TT. Using a standardized, controlled protocol we investigated the effects of phorbol ester (TPA) and a physiological stimulus (PDGF+IL-1) on MMP-9 expression in cultured SV-SMC from 15 CC, 15 CT and 3 TT patients, and on PDGF+IL-1-induced SV-SMC invasion (Boyden chamber with Matrigel barrier). A strong correlation between MMP-9 mRNA levels (real-time RT-PCR) and MMP-9 protein secretion (gelatin zymography) was observed. However, no significant differences were observed in MMP-9 expression levels, or in SV-SMC invasion, between cells with different -1562C/T genotypes. Moreover, MMP-9 promoter activity of the C and T variants was similar. Our data challenge the functional nature of the -1562C/T polymorphism and its capacity to modulate MMP-9 expression levels and SV-SMC invasion, and hence susceptibility to vascular pathologies in vivo.
Maqbool
Azhar
A
Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds, UK.
Turner
Neil A
NA
Galloway
Stacey
S
Riches
Kirsten
K
O'Regan
David J
DJ
Porter
Karen E
KE
D000077214:Becaplermin; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics*; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D053582:Interleukin-1alpha / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics* / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000201:enzymology*; D010641:Phenotype; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000378:metabolism; D012501:Saphenous Vein / Q000201:enzymology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D053582:Interleukin-1alpha; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D000077214:Becaplermin; D020780:Matrix Metalloproteinase 9; D013755:Tetradecanoylphorbol Acetate