MMP‐2 and MMP‐9 and Their Tissue Inhibitor in Preterm Human Milk

Abstract

Matrix metalloproteinases (MMPs) are a group of endopeptidases that play a key role in the degradation of the extracellular matrix. The natural inhibitors of MMPs are the tissue inhibitors of metalloproteinases (TIMPs). It has been shown that several MMPs may be major factors in tissue destruction and remodeling in necrotizing enterocolitis. We designed the present prospective observational study to determine whether specific MMPs activity and expression of their inhibitors are similar in the milk fed to preterm and term infants. We compared specific matrix metalloproteinases (MMP-2 and MMP-9) and 1 MMP inhibitor (TIMP-1) activities or expression in human milk (HM) fed to 18 preterm infants and 13 full-term infants, obtained at 72 hours and 1 and 2 weeks postpartum. MMP-2 and MMP-9 activities were similar in both groups and did not vary over time. TIMP-1 was significantly higher in preterm HM. TIMP-1 expression increased significantly over time exclusively in the preterm group. There are differences in the expression of TIMP-1 between colostrum and mature milk in preterm HM and differences in the expression of TIMP-1 between preterm and term milk.