Expression of matrix metalloproteinase-1 mRNA in peripheral blood mononuclear cells of systemic lupus erythematosus patients and its relationship with atherosclerosis

Background Matrix metalloproteinase-1 （MMP-1） plays an important role in atherosclerosis. This study was to examine expression of MMP-1 mRNA in peripheral blood mononuclear cells （PBMCs） of patients with systemic lupus erythematosus （SLE）, and to explore its relationship with atherosclerosis in SLE. Methods Fluorescent quantitative reverse transcription polymerase chain reaction （RT-PCR） was used to examine the expression of MMP-1 mRNA in PBMCs in 80 SLE patients, including 39 prone to atherosclerosis （Group A） and 41 unprone to atherosclerosis （Group B）. Meanwhile, 30 patients who were free of cardiovascular diseases and 30 healthy individuals were selected as disease and normal control group （Groups C and D）. The changes of MMP-1 gene expression were analyzed by differences of cycle threshold （ACt）, with the following formula： ACt = Cttarget gene - Ctreference gene. Results The expression level of MMP-1 mRNA in Group A was significantly higher than that of group B （ACt=8.64±2.43 vs ACt=12.09±2.26, t=6.588, P 〈0.01）. The expression level of MMP-1 mRNA of SLE patients was significantly higher than that of Group C （ACt=10.41±2.90 vs ACt=12.29±2.51, t=3.135, P 〈0.01） and Group D （ACt=10.41±2.90 vs ACt=12.48±1.69, t=3.675, P 〈0.01）. Conclusions In comparison to disease and control group, expression of MMP-1 mRNA in PBMCs of SLE patients was significantly elevated, and significant difference of MMP-1 mRNA expression was also found between SLE patients prone and unprone to atherosclerosis, indicating that expression of MMP-1 mRNA may be correlated with the pathogenesis and activity of atherosclerosis in SLE.