Strong expression of many matrix metalloproteinases (MMPs) has been related to poor survival of colorectal cancer (CRC) patients. The expression of tissue inhibitors of metalloproteinases (TIMPs) has been associated with both a beneficial and a poor outcome and there is thus a need to further clarify the significance of MMPs and TIMPs in CRC. The prognostic significance of 4 MMPs and TIMPs in CRC was evaluated. Formalinfixed, paraffin-embedded tissue arrayed samples of 351 patients with primary colon or rectal cancer of Dukes' stages A-D were selected for immunohistochemical staining of MMP-1, -2, -7 and -13, and TIMP-1, -2, -3 and -4. High expression of MMP-2 in the malignant epithelium as well as in the surrounding stroma was associated with reduced survival of colon cancer patients. Strong epithelial and stromal cytoplasmic staining of TIMP-3 was associated with a longer survival in rectal cancer patients, and here the interobserver variation for evaluating the degree of staining was lower than for epithelial staining. Strong stromal cytoplasmic staining of TIMP-4 predicted longer survival of rectal cancer patients. Multivariate analysis showed that stromal cytoplasmic TIMP-3 staining was the only marker of independent prognostic value. MMP-2 might be a useful prognostic marker in colon cancer, and TIMP-3 and TIMP-4 in rectal cancer, but the findings associated with stromal staining should be interpreted with some caution. Different biologic behavior or different genetic development may explain the differences between colon and rectal cancers regarding the expression of MMP-2, TIMP-3 and TIMP-4. ' 2007 Wiley-Liss, Inc.Key words: colorectal cancer; matrix metalloproteinases; tissue inhibitors of metalloproteinases; prognosis; survival Matrix metalloproteinases (MMPs) are a large family of zincdependent neutral endopeptidases that play an important role in the degradation of all matrix components crucial for malignant tumor growth, invasion and metastasis. 1,2 Metalloproteinases are inhibited by tissue inhibitors (TIMPs) which are secreted proteins. These bioactive substances are specific inhibitors of MMPs that bind to enzymatically active MMPs at a 1:1 molar stoichiometry thus inhibiting proteolysis. 3 The role of TIMPs for the homeostasis of the extracellular matrix is critical and may inhibit or stimulate tumorigenesis. 4 Many studies have shown that the expression of several MMPs is enhanced in a number of malignancies, including colorectal cancer (CRC), but the relation between the expression of MMPs and overall patient survival is not clear. 5,6 Enhanced expression of MMP-1, -7 and -13 has been reported to be associated with metastasis and poor survival of patients with CRC. 7-9 Tissue concentrations of MMP-1, MMP-2 and TIMP-1 are increased in CRC compared to healthy colorectal tissue. This has been related to the role of these endogenous substances in cancer progression. 2 Healthy tissue may contain high levels of TIMP-2 10 and the levels of TIMP-3 mRNA are regionally increased in moderately and poorl...

Neonatal pulmonary vein banding in piglets recapitulates critical aspects of clinical PVS and highlights a pathologic profile consistent with EndMT, supporting the rationale for evaluating therapeutic strategies designed to exploit reversibility of upstream pulmonary vein pathology.

Tissue inhibitor of metalloproteinases 4 (TIMP4) is expressed highly in heart and found dysregulated in human cardiovascular diseases. It controls extracellular matrix remodeling by inhibiting matrix metalloproteinases (MMPs) and is implicated in processes including cell proliferation, apoptosis, and angiogenesis. Timp4-deficient mice (Timp4 ؊/؊ ) were generated to assess TIMP4 function in normal development and in models of heart disease. We deleted exons 1-3 of the Timp4 gene by homologous recombination. Timp4 ؊/؊ mice are born healthy, develop normally, and produce litters of normal size and gender distribution. These mice show no compensation by overexpression of Timp1, Timp2, or Timp3 in the heart. Following cardiac pressure overload by aortic banding, Timp4 ؊/؊ mice have comparable survival rate, cardiac histology, and cardiac function to controls. In this case, Timp4 deficiency is compensated by increased cardiac Timp2 expression. Strikingly, the induction of myocardial infarction (MI) leads to significantly increased mortality in Timp4 ؊/؊ mice primarily due to left ventricular rupture. The post-MI mortality of Timp4 ؊/؊ mice is reduced by administration of a synthetic MMP inhibitor. Furthermore, combining the genetic deletion of Mmp2 also rescues the higher post-MI mortality of Timp4 ؊/؊ mice. Finally, Timp4 ؊/؊ mice suffer reduced cardiac function at 20 months of age. Timp4 is not essential for murine development, although its loss moderately compromises cardiac function with aging. Timp4 ؊/؊ mice are more susceptible to MI but not to pressure overload, and TIMP4 functions in its capacity as a metalloproteinase inhibitor after myocardial infarction.Tissue inhibitors of metalloproteinases (TIMPs) 5 comprise a family of four endogenous inhibitors. Classically, matrix metalloproteinases (MMPs) and TIMPs are known as important regulators of extracellular matrix turnover during physiologic and numerous pathologic processes. Several other functions also have been ascribed to MMPs, many of which extend to their inhibitors (1). TIMPs also exhibit functions that appear to be independent of their metalloproteinase inhibitory capacity (2).TIMP4 is the most recently discovered member of the TIMP family. It inhibits several soluble MMPs (types 1, 2, 3, 7, 8, 9, 12, 13, 19, and 26) and membrane-type MMPs (MT1, MT2, and MT3) (3-7). TIMP4 also inhibits a disintegrin and metalloproteinase (ADAM) 28 and ADAM33 (7) but not ADAM10 (which is inhibited by TIMP1 and TIMP3) or ADAM17 (which is inhibited only by TIMP3) (2,7,8). Inhibition of the ADAMTS (ADAM with thrombospondin motifs) family by TIMP4 has not yet been reported. Although Timp genes 1, 2, and 3 are widely expressed, the Timp4 gene exhibits a restricted tissue expression pattern, with the highest expression in the heart, followed by brain, ovary, and skeletal muscle, and TIMP4 protein is detectable in the serum (9 -11). Several lines of evidence suggest a specific role in cardiovascular pathology: Timp4 is induced following endothelial injury of rat carotid art...

Tissue inhibitors of matrix metalloproteinases (TIMPs) comprise a family of four members, of which TIMP4 is characterized by being primarily restricted to cardiovascular structures. We demonstrate with immunohistochemical analysis of healthy human tissue that TIMP4 is present in medial smooth muscle cells and adventitial capillaries of arteries as well as in cardiomyocytes. Animal studies have suggested a role for TIMP4 in several inflammatory diseases and cardiovascular pathologies. We therefore examined whether TIMP4 is involved in human inflammatory cardiovascular disorders, specifically atherosclerosis, giant cell arteritis and chronic rejection of heart allografts. TIMP4 was most clearly visible in cardiovascular tissue areas populated by abundant inflammatory cells, mainly macrophages and CD3+ T cells. Using western blotting and immunocytochemistry, human blood derived lymphocytes, monocytes/macrophages and mast cells were shown to produce TIMP4. In advanced atherosclerotic lesions, TIMP4 was detected around necrotic lipid cores, whereas TIMP3 and caspase 3 resided within and around the core regions, indicating different roles for TIMP3 and TIMP4 in inflammation-induced apoptosis and in matrix turnover. In conclusion, the data demonstrate upregulation of TIMP4 in human cardiovascular disorders exhibiting inflammation, suggesting its future use as a novel systemic marker for vascular inflammation.