Matrix metalloproteinase 2 and tissue inhibitors of metalloproteinases regulate human aortic smooth muscle cell migration during in vitro aging

Abstract

As a direct correlation between aging and the risk of onset of vascular disease has been universally accepted, we prepared an in vitro aging model consisting in sequential passages of human aortic smooth muscle cells (AoSMC) in order to evaluate the cell behavior changes during aging. Because matrix metalloproteinases (MMP) are actively involved in matrix remodeling and disease outcome, in our model we found active MMP-2 only in the conditioned medium of young AoSMCs, whereas aged cells showed only the inactive zymogen form of MMP-2 (pro-MMP-2). We ascribed the pro-MMP-2 activation in young cells to an increase in membrane type 1 matrix metalloproteinase (MT1-MMP) content. Furthermore, we found that transcripts coding for tissue inhibitor of metalloproteinases (TIMPs) were up-regulated in aged cells, and this increase of TIMPs could also prevent pro-MMP-2 activation in aged cells. Moreover, we demonstrated that young AoSMCs possess higher migratory capabilities than aged cells. The young AoSMC migration can be inhibited by adding TIMP-1 and TIMP-2 to the cells reproducing aged AoSMC migratory behavior. Finally, the role of MMP-2 and TIMP-2 in AoSMC migration was confirmed silencing MMP-2 and TIMP-2 in young and aged AoSMCs, respectively; therefore, in this study we showed that these enzymes play a pivotal role in the regulation of the AoSMC migration during in vitro aging.

Glycosaminoglycans and Glucose Prevent Apoptosis in 4-Methylumbelliferone-treated Human Aortic Smooth Muscle Cells

“…As shown in Fig. 4B, NH 4 Cl alone did not decrease viability of the cells, and it did not alter the effect of HMW-HA to prevent the decrease in viability in the presence of 4-MU. Furthermore, NH 4 Cl alone did not prevent the decrease of viability in the presence of 4-MU.…”

“…UDP sugars or energy) through the action of several lysosomal glycosidases. To test this possibility, we treated AoSMCs with NH 4 Cl, a well known inhibitor of lysosomal enzymes. As shown in Fig.…”

“…CD44 siRNA (s2681) and scramble negative control siRNA1 kit (code 4611) were both purchased from Ambion. The transfections were done using a Nucleofector apparatus (Amaxa) as described previously (4,21). After 48 h of incubation, cells were treated with 4-MU, and HMW-HA and cell viability were measured.…”

Proinflammatory Cytokines Induce Hyaluronan Synthesis and Monocyte Adhesion in Human Endothelial Cells through Hyaluronan Synthase 2 (HAS2) and the Nuclear Factor-κB (NF-κB) Pathway

“…4611), both from Ambion. The transfections were done using a Nucleofector apparatus (Lonza) and the human HUVEC Nucleofector kit as described previously (21). After 48 h of incubation, the silencing efficiency was quantified by quantitative RT-PCR measuring the HAS2 mRNA transcript.…”

Chlorotyrosine promotes human aortic smooth muscle cell migration through increasing superoxide anion production and ERK1/2 activation

“…Many growth factors such as platelet-derived growth factor-BB (PDGF-BB) play crucial roles in VSMC migration. Matrix metalloproteinases (MMPs) and integrins provide permissive effects for VSMC migration by breaking down major extracellular barriers such as basal membranes, interstitial collagens, and proteoglycans [8].…”