Association between matrix metalloproteinase (MMP)-2 polymorphisms and MMP-2 levels in hypertensive disorders of pregnancy

We examined whether two functional polymorphisms (g.-1306 C > T and g.-735 C > T) in matrix metalloproteinase (MMP)-2 gene are associated with preeclampsia (PE) or gestational hypertension (GH), and whether they modify MMP-2 or tissue inhibitor of metalloproteinase (TIMP)-2 plasma concentrations in these hypertensive disorders of pregnancy. We studied 130 healthy pregnant (HP), 130 pregnant with GH, and 133 pregnant with PE. Genomic DNA was extracted from whole blood and genotypes for g.-1306 C > T and g.-735 C > T polymorphisms were determined by Real Time-PCR, using Taqman allele discrimination assays. Haplotypes were inferred using the PHASE program. Plasma MMP-2 and TIMP-2 concentrations were measured by ELISA. The main findings were that pregnant with PE have higher plasma MMP-2 and TIMP-2 concentrations than HP (P < 0.05), although the MMP-2/TIMP-2 ratios were similar (P > 0.05). Moreover, pregnant with GH have elevated plasma MMP-2 levels and MMP-2/TIMP-2 ratios compared to HP (P < 0.05). While MMP-2 genotypes and haplotypes are not linked with hypertensive disorders of pregnancy, MMP-2 genotypes and haplotypes are associated with significant alterations in plasma MMP-2 and TIMP-2 concentrations in preeclampsia (P < 0.05). Our findings may help to understand the relevance of MMP-2 and its genetic polymorphisms to the pathophysiology of hypertensive disorders of pregnancy. It is possible that patients with PE and the MMP-2 haplotype combining the C and T alleles for the g.-1306 C > T and g.-735 C > T polymorphisms may benefit from the use of MMPs inhibitors such as doxycycline. However, this possibility remains to be determined.

► Matrix metalloproteinase (MMP)-2 contributes to hypertensive disorders of pregnancy.
► Genetic MMP-2 polymorphisms may modify MMP-2 levels.
► Our findings show that MMP-2 polymorphisms affect MMP-2 levels in preeclampsia.