Type IV collagenase(s) and TIMPs modulate endothelial cell morphogenesis in vitro

Abstract

It has been proposed that proteases are important in endothelial cell behavior. We examined the contribution of the gelatinase/type IV collagenase system in an in vitro model of endothelial differentiation. Human umbilical vein endothelial cells rapidly align and form networks of tubes when cultured on a basement membrane preparation, Matrigel. Zymograms of culture supernates demonstrate a 72-kD and a 92-kD gelatinase activity; the cells produce most of the 72-kD gelatinase, whereas the 92-kD activity is derived entirely from the Matrigel. Addition of antibodies against type IV gelatinase/collagenase decreases the area of the tube network. Both tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2, similarly decrease tube formation when added to cultures. Conversely, exogenous recombinant 72-kD gelatinase increases tube-forming activity. The effects of the anti-gelatinase antibodies and the TIMPs are not additive. Inhibition by either antibodies or TIMPs is greatest when they are added at culture initiation, suggesting that the protease activity is important in the early steps of morphogenesis. However, culture of the cells on Matrigel does not increase early expression of mRNA for the 72-kD gelatinase. Expression of message for the enzyme actually decreases during the course of the assay, while transcription of mRNAs for TIMPs increases, further supporting the concept that collagenases facilitate an early event in tube formation. These data demonstrate that gelatinase/type IV collagenase activity is important in endothelial cell morphogenesis on Matrigel, and suggest a role for collagenases in formation of new capillaries in vivo.

Shedding of the Matrix Metalloproteinases MMP-2, MMP-9, and MT1-MMP as Membrane Vesicle-Associated Components by Endothelial Cells

“…This is in agreement with studies on MMP-2 and MT1-MMP that reported that small amounts of these MMPs are essential for the onset of the morphogenetic program, whereas an excess of proteolytic activity prevents tubulogenesis and cause the reabsorption of the formed vasculature-through loss of the matrix-supporting scaffold necessary for maintaining the structure-and promotes cell invasion. 27,[32][33][34] In this respect, the need for a delicate balance between proteases and their inhibitors in each phase of the angiogenic process could provide an addition functional explanation for the presence of TIMPs in vesicles shed by endothelial cells.…”

Humoral and cellular immunity induced by tumor cell vaccine based on the chicken xenogeneic homologous matrix metalloproteinase-2

“…To date, several studies have demonstrated that the gelatinases, MMP-2 and MMP-9, are involved in vascular cell migration and invasion assays. [28][29] It has been documented that MMP-2 mediates the tumorassociated angiogenesis. 30,31 Microvessel density has been found to correlate with the capacity of the tumor to metastasize, and thus is considered to be one of the most important predictors of tumor progression.…”

Imbalance between serum matrix metalloproteinase-2 and its inhibitor as a predictor of recurrence of urothelial cancer

“…The TIMP-2 expression as detected by immunohistochemistry was associated with poor outcome in invasive bladder cancer patients (Grignon et al, 1996). However, several investigators have shown that the balance between MMPs and their inhibitors (TIMPs) modulated endothelial cell morphogenesis in vitro, and that TIMPs inhibited the early events in tube formation by endothelial cells on Matrigel (Schnaper et al, 1993). Therefore, MMPs and TIMPs in circulating body fluids may also contribute to the regulation of tumour metastasis, invasion and angiogesesis DeClerck et al, 1994).…”