Activated protein C prevents inflammation yet stimulates angiogenesis to promote cutaneous wound healing.

Activated protein C (APC) is a serine protease that plays a central role in physiological anticoagulation, and has more recently been shown to be a potent anti-inflammatory mediator. Using cultured human cells, we show here that APC up-regulates the angiogenic promoters matrix metalloproteinase-2 in skin fibroblasts and umbilical vein endothelial cells, vascular endothelial growth factor in keratinocytes and fibroblasts, and monocyte chemoattractant protein-1 in fibroblasts. In the chick embryo chorioallantoic membrane assay, APC promoted the granulation/remodeling phases of wound healing by markedly stimulating angiogenesis as well as promoting reepithelialization.

Elevation of activated protein C in synovial joints in rheumatoid arthritis and its correlation with matrix metalloproteinase 2.

Objective: To investigate the involvement of the anticoagulant serine protease activated protein C (APC) in tissue remodeling in rheumatoid arthritis (RA).

Methods: PC/APC, matrix metalloproteinase 2 (MMP-2), and MMP-9 were detected in synovial fluid by Western blotting, and their antigen levels were quantified by enzyme-linked immunosorbent assay in patients with osteoarthritis (OA) or RA. Enzymatic activity of MMP-2 was assayed using a specific fluorogenic substrate.

The metalloprotease-directed shedding of BP 180 (collagen XVII) from human keratinocytes in culture is unaffected by ceramide and cell-matrix interaction.

The constitutive shedding of BP180 (collagen XVII) from human keratinocytes in culture was totally prevented by batimastat (5 microM), a wide spectrum matrix metalloprotease (MMP) inhibitor. However, keratinocytes did not express active MMP and generation of active Gelatinase A (MMP-2) and Gelatinase B (MMP-9) at the cell plasma membrane by increasing the ceramide content of keratinocytes did not influence BP180 processing to a 120 kDa species. A disintegrin and metalloprotease (ADAM) is probably involved in such a shedding event since release of 120 kDa polypeptide was inhibited by Decanoyl-Arg-Val-Lys-Arg CH2Cl (30 microM), a specific furin convertase inhibitor; culturing cells on to several matrix substrata i.

Involvement of the ceramide signaling pathway in modulating the differentiated state of porcine thyroid cells.

Neutral sphingomyelinase (Smase) is a cell membrane-associated phospholipase that hydrolyzes sphingomyelin to phosphocholine and ceramide, a lipid second messenger involved in cell differentiation and/or apoptosis. We first evidenced that porcine cultured thyroid cells could express neutral Smase activity even if thyrotropin (TStH), an essential hormone in thyroid cell differentiation, was found to induce a 1.7-fold decrease in Smase activity.

Relationship between cell-associated matrix metalloproteinase 9 and psoriatic keratinocyte growth.

Primary cultures of psoriatic keratinocytes proliferated at a higher rate and produced lower amounts of matrix metalloproteinase 9 than normal keratinocytes cultured under similar conditions. Sup- plementation of psoriatic keratinocyte cell culture medium with batimastat or the use of a matrix metalloproteinase 9 blocking antibody further stimulated psoriatic keratinocyte growth. An increase in intracellular ceramide level enhanced matrix metalloproteinase 9 production and inhibited cell proliferation in parallel.