Proteolysis Of Extracellular Matrix Proteins Research Articles

MMP-7 derived peptides with MHC class-I binding motifs from canine mammary tumor tissue elicit strong antigen-specific T-cell responses in BALB/c mice.

Matrix Metalloproteinases (MMPs)-induced altered proteolysis of extracellular matrix proteins and basement membrane holds the key for tumor progression and metastasis. Matrix metalloproteinases-7 (Matrilysin), the smallest member of the MMP family also performs quite alike; thus serves as a potential candidate for anti-tumor immunotherapy. Conversely, being an endogenous tumor-associated antigen (TAA), targeting MMP-7 for immunization is challenging. But MMP-7-based xenovaccine can surmount the obstacle of poor immunogenicity and immunological tolerance, often encountered in TAA-based conventional vaccine for anti-tumor immunotherapy. This paves the way for investigating the potential of MMP-7-derived major histocompatibility complex (MHC)-binding peptides to elicit precise epitope-specific T-cell responses towards their possible inclusion in anti-tumor vaccine formulations. Perhaps it also ushers the path of achieving multiple epitope-based broad and universal cellular immunity. In current experiment, an immunoinformatics approach has been employed to identify the putative canine matrix matelloproteinases-7 (cMMP-7)-derived peptides with MHC class-I-binding motifs which can elicit potent antigen-specific immune responses in BALB/c mice. Immunization with the cMMP-7 DNA vaccine induced a strong CD8+ cytotoxic T lymphocytes (CTLs) and Th1- type response, with high level of gamma interferon (IFN-γ) production in BALB/c mice. The two identified putative MHC-I-binding nonameric peptides (Peptide32-40 and Peptide175-183) from cMMP-7 induced significant lymphocyte proliferation along with the production of IFN-γ from CD8+ T-cells in mice immunized with cMMP-7 DNA vaccine. The current observation has depicted the immunogenic potential of the two cMMP-7-derived nonapeptides for their possible exploitation in xenovaccine-mediated anti-tumor immunotherapy in mouse model.

Matrix metalloproteinase-2 and -9 in the cerebellum of teleost fish: Functional implications for adult neurogenesis.

Matrix metalloproteinases (MMPs) are a family of highly conserved zinc-dependent proteases involved in both development and pathogenesis. The present study examines the role of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) in adult neurogenesis, using the corpus cerebelli, a subdivision of the cerebellum, of knifefish (Apteronotus leptorhynchus) as a model system. Transcripts of five isoforms of these gelatinases were identified in the central nervous system of this species. Sequence similarity analysis and homology modeling indicated that functionally and structurally critical elements were highly conserved in knifefish gelatinases. Immunohistochemical staining revealed a differential distribution of MMP-2 and MMP-9 at both the cellular and subcellular level. MMP-2 expression was found mainly in Sox2-immunopositive stem/progenitor cells, both quiescent and mitotically active; and was localized in both the cytoplasmic compartment and the nucleus. By contrast, MMP-9 immunoreactivity was absent in neurogenic niches and displayed a more homogenous distribution, with low to moderate intensity levels, in the molecular and granular layers. MMP-9 expression appeared to be restricted to the extracellular space. In situ zymography indicated that gelatinase activity matched the cellular and subcellular distributions of the two MMPs. The observed patterns of gelatinase activity and expression support the hypothesis that MMP-2 is primarily involved in regulation of the activity of stem/progenitor cells that give rise to new granule neurons, whereas MMP-9 facilitates migration of the progeny of these cells by proteolysis of extracellular matrix proteins.

Soluble urokinase-type plasminogen activator receptor (suPAR) in multiple respiratory diseases

Serum soluble urokinase-type plasminogen activator receptor (suPAR) is a glycoprotein secreted during infections and inflammation [1]. Urokinase-type plasminogen activator (uPA) is secreted by polymorphonuclear neutrophils (PMN) and macrophages; then uPA binds to membrane urokinase-type plasminogen activator receptor (uPAR) [2]. suPAR is formed by cleaved from the uPAR [2]. suPAR is expressed in various cell types, such as macrophages monocytes, endothelial cells and neutrophils [3]. suPAR can be potentially cause or modulate various diseases in patients with cancer, various infectious and inflammatory diseases (including infections with human immunodeficiency virus (HIV), tuberculosis, liver fibrosis and inflammatory bowel disease) [2, 3]. suPAR can convert plasminogen to plasmin, which degrades fibrin, activates matrix metalloproteases and mediates proteolysis of extracellular matrix proteins during cellular invasion [4]. suPAR modulate the functions of integrins (including activating intracellular signals, monocyte chemotaxis, cell adhesion and proliferation) [4, 5]. So suPAR contributes to cell adhesion, migration, proliferation inflammation, chemotaxis, proteolysis, immune system activation, tissue remodeling and signal transduction [5, 6]. Several studies have identified that suPAR level is a important marker in patients with various diseases and associated with a poorer outcome in a range of non-infectious and infectious diseases [2]. Biomarkers of lung disease are required to aid diagnosis, define clinical phenotypes and monitor the response to existing and new therapeutic strategies. Our review aims to explore the potential of suPAR as a general marker in the diagnosis, prognosis and follow-up of therapy of lung disease.

High-Density Lipoproteins Limit Neutrophil-Induced Damage to the Blood–Brain Barrier in Vitro

Breakdown of the blood-brain barrier (BBB) is a key step associated with ischemic stroke and its increased permeability causes extravasation of plasma proteins and circulating leukocytes. Polymorphonuclear neutrophil (PMN) proteases may participate in BBB breakdown. We investigated the role of PMNs in ischemic conditions by testing their effects on a model of BBB in vitro, under oxygen-glucose deprivation (OGD) to mimic ischemia, supplemented or not with high-density lipoproteins (HDLs) to assess their potential protective effects. Human cerebral endothelial cells cultured on transwells were incubated for 4 hours under OGD conditions with or without PMNs and supplemented or not with HDLs or alpha-1 antitrypsin (AAT, an elastase inhibitor). The integrity of the BBB was then assessed and the effect of HDLs on PMN-induced proteolysis of extracellular matrix proteins was evaluated. The release of myeloperoxidase and matrix metalloproteinase 9 (MMP-9) by PMNs was quantified. Polymorphonuclear neutrophils significantly increased BBB permeability under OGD conditions via proteolysis of extracellular matrix proteins. This was associated with PMN degranulation. Addition of HDLs or AAT limited the proteolysis and associated increased permeability by inhibiting PMN activation. Our results suggest a deleterious, elastase-mediated role of activated PMNs under OGD conditions leading to BBB disruption that could be inhibited by HDLs.

Myocardial Structure and Matrix Metalloproteinases

Metalloproteinases (MMPs) are enzymes which enhance proteolysis of extracellular matrix proteins. The pathophysiologic and prognostic role of MMPs has been demonstrated in numerous studies. The present review covers a wide a range of topics with regards to MMPs structural and functional properties, as well as their role in myocardial remodeling in several cardiovascular diseases. Moreover, the clinical and therapeutic implications from their assessment are highlighted.

Serine Proteases in Bone Disease

Serine proteases are active in many physiological and pathological processes within bone tissue. Although essential to adequate maintenance of bone and cartilage, their inappropriate expression can lead to exacerbation of tissue destruction and inflammation. Their effects are exerted through multiple pathways, including interaction with signalling molecules such as transforming growth factor β (TGFβ), binding to protease-activated receptors (PARs), and direct proteolysis of extracellular matrix proteins, in some cases working synergistically with matrix metalloproteases in the remodelling of bone tissue. The overall effect of these interactions is not yet clear, but there are strong links between some serine proteases and arthropathies, in addition to metastatic bone invasion. Understanding the contribution of each of these enzymes to the molecular disease process is crucial to developing effective treatment based on inhibitors or agonists. Serine protease inhibitors have shown promise in reducing the severity of arthritis, but greater specificity is required to avoid undesired systemic effects. Keywords: Arthritis, uPA, HtrA1, collagen, inflammation, bone matrix

Regulation of thrombospondin1 by extracellular proteases.

The contribution of proteases to developmental, physiological and pathological processes has been well accepted. Cleavage of matrix proteins is a key requirement for cell migration and remodeling of the extracellular environment. The constant process of matrix turnover is dependent on the delicate balance between degradation and synthesis. In addition, regulated proteolysis also allows for the release and activation of growth factors and cytokines. Similarly to other extracellular matrix proteins, thrombospondins are also targets of proteolysis. While in some cases enzymatic activity is associated with degradation of the protein; in other situations, targeted and selective cleavage offers the means to release polypeptides with either alternative or enhanced function. Here, we provide a summary of the published information related to thrombospondin proteolysis within the context of how proteolysis of extracellular matrix proteins impacts diversification of protein function. We also discuss its biological relevance and potential therapeutic value of thrombospondin proteolysis with particular emphasis on angiogenesis.

Coronary Artery Aneurysm: A Review and Hypothesis Regarding Etiology

Abstract Context.—Coronary artery aneurysm is an uncommon condition that can be a cause of death when it thromboses or ruptures. It is always associated with destruction of the tunica media, usually associated with atherosclerosis, and commonly associated with chronic inflammation. Objective.—To review the pathology, epidemiologic and clinical features, and pathophysiology of coronary artery aneurysm, particularly new research results, drawing out implications for the understanding, diagnosis, and treatment of this condition. Data Sources.—Pertinent literature and illustrative cases at our institution. Conclusions.—Inflammation spilling over into the tunica media from the tunica intima may link atherosclerosis to aneurysm formation, but vasculitis without atherosclerosis causes coronary artery aneurysms in young children with Kawasaki disease. Increased proteolysis of extracellular matrix proteins is probably one mechanism of coronary artery aneurysm formation, either due to overactive matrix metalloprote...

Coronary Artery Aneurysm: A Review and Hypothesis Regarding Etiology

Coronary artery aneurysm is an uncommon condition that can be a cause of death when it thromboses or ruptures. It is always associated with destruction of the tunica media, usually associated with atherosclerosis, and commonly associated with chronic inflammation. To review the pathology, epidemiologic and clinical features, and pathophysiology of coronary artery aneurysm, particularly new research results, drawing out implications for the understanding, diagnosis, and treatment of this condition. Pertinent literature and illustrative cases at our institution. Inflammation spilling over into the tunica media from the tunica intima may link atherosclerosis to aneurysm formation, but vasculitis without atherosclerosis causes coronary artery aneurysms in young children with Kawasaki disease. Increased proteolysis of extracellular matrix proteins is probably one mechanism of coronary artery aneurysm formation, either due to overactive matrix metalloproteinases or underactive inhibition of these proteinases, and an excess of transforming growth factor beta may be another mechanism in the pathogenesis. Coronary atherosclerosis is a universal disease of adults, but only 1.5% of them have coronary aneurysms; this small group may be those with a second coronary artery disease, such as vasculitis.

Inhibition of matrix metalloproteinases prevents peroxynitrite‐induced contractile dysfunction in the isolated cardiac myocyte

The potent oxidant peroxynitrite (ONOO(-)) induces mechanical dysfunction in the intact heart in part through activation of matrix metalloproteinase-2 (MMP-2). This effect may be independent of the proteolytic actions of MMPs on extracellular matrix proteins. The purpose of this study was to examine the effects of ONOO(-) on contractile function at the level of the single cardiac myocyte and whether this includes the action of MMPs. Freshly isolated ventricular myocytes from adult rats were superfused with Krebs-Henseleit buffer at 21 degrees C and paced at 0.5 Hz. Contractility was measured using a video edge-detector. ONOO(-) or decomposed ONOO(-) (vehicle control) were co-infused over 40 min to evaluate the contraction cease time (CCT). The effects of ONOO(-) on intracellular [Ca(2+)] were determined in myocytes loaded with calcium green-1 AM. MMP-2 activity was measured by gelatin zymography. ONOO(-) (30-600 microM) caused a concentration-dependent reduction in CCT. Myocytes subjected to 300 microM ONOO(-) had a shorter CCT than decomposed ONOO(-) (14.9+1.5 vs 32.2+3.5 min, n=7-8; P<0.05) and showed increased MMP-2 activity. The MMP inhibitors doxycycline (100 microM) or PD 166793 (2 microM) reduced the decline in CCT induced by 300 microM ONOO(-). ONOO(-) caused shorter calcium transient cease time and significant alterations in intracellular [Ca(2+)] homoeostasis which were partially prevented by doxycycline. This is the first demonstration that inhibition of MMPs protects the cardiac myocyte from ONOO(-)-induced contractile failure via an action unrelated to proteolysis of extracellular matrix proteins.

Abdominal aortic pseudoaneurysm caused by prolonged methicillin-resistant Staphylococcus aureus sepsis

The mechanism of pseudoaneurysm formation caused by prolonged sepsis is thought to be related to the vascular endothelium being directly invaded and broken by bacteria. Moreover, matrix metalloproteinases (MMPs) which are up-regulated by chronic inflammation have been reported to be implicated in the pathogenesis of aneurysm development through increased proteolysis of extracellular matrix proteins. An effective treatment for infected pseudoaneurysm remains unsettled. Surgery is generally performed, however, because the patients in most of these cases are in very poor physical condition, the operation is associated with high morbidity and mortality. A more successful alternative is endovascular treatment. Recent reports indicate low morbidity and mortality rates with this treatment. If the patient in this case had been in better condition, we could have selected endovascular stent-grafting for her treatment.

Advanced glycation endproducts: what is their relevance to diabetic complications?

Glycation is a major cause of spontaneous damage to proteins in physiological systems. This is exacerbated in diabetes as a consequence of the increase in glucose and other saccharides derivatives in plasma and at the sites of vascular complications. Protein damage by the formation of early glycation adducts is limited to lysine side chain and N-terminal amino groups whereas later stage adducts, advanced glycation endproducts (AGEs), modify these and also arginine and cysteine residues. Metabolic dysfunction in vascular cells leads to the increased formation of methylglyoxal which adds disproportionately to the glycation damage in hyperglycaemia. AGE-modified proteins undergo cellular proteolysis leading to the formation and urinary excretion of glycation free adducts. AGEs may potentiate the development of diabetic complications by activation of cell responses by AGE-modified proteins interacting with specific cell surface receptors, activation of cell responses by AGE free adducts, impairment of protein-protein and enzyme-substrate interactions by AGE residue formation, and increasing resistance to proteolysis of extracellular matrix proteins. The formation of AGEs is suppressed by intensive glycaemic control, and may in future be suppressed by thiamine and pyridoxamine supplementation, and several other pharmacological agents. Increasing expression of enzymes of the enzymatic defence against glycation provides a novel and potentially effective future therapeutic strategy to suppress protein glycation.

Elevation of Serum Matrix Metalloprotease (MMP)-2 and Oxidant Stress in Patients with Acute Worsening of Chronic Heart Failure

Purpose: Matrix metalloproteases (MMPs) are a family of enzymes that catalyze proteolysis of extracellular matrix proteins including collagen fibers. MMP-1 is highly specific for fibrillar collagen, whereas MMP-2 degrades laminin and fibronectin as well as collagen so that MMP-2 disrupts engagement of cardiomyocytes to extracellular matrix. We have recently reported the enhancement of oxidant stress and collagen synthesis at acute worsening of chronic heart failure (CHF) (J Am Coll Cardiol. 2005, 45 Suppl.

Elevated levels of matrix metalloprotein-3 in patients with coronary aneurysm: A case control study.

BackgroundMatrix metalloproteinases (MMPs) have been implicated in the pathogenesis of arterial aneurysms through increased proteolysis of extracellular matrix proteins. Increased proteolysis due to elevated matrix degrading enzyme activity in the arterial wall may act as a susceptibility factor for the development of coronary aneurysms. The aim of this study was to investigate the association between MMPs and presence of coronary aneurysms.MethodsThirty patients with aneurysmal coronary artery disease and stable angina were enrolled into study (Group 1). Fourteen coronary artery disease patients with stable angina were selected as control group (Group 2). MMP-1, MMP-3 and C-reactive protein (CRP) were measured in peripheral venous blood and matched between the groups.ResultsSerum MMP-3 level was higher in patients with aneurismal coronary artery disease compared to the control group (20.23 ± 14.68 vs 11.45 ± 6.55 ng/ml, p = 0.039). Serum MMP-1 (13.63 ± 7.73 vs 12.15 ± 6.27 ng/ml, p = 0.52) and CRP levels (4.78 ± 1.47 vs 4.05 ± 1.53 mg/l, p = 0.13) were not significantly different between the groups.ConclusionMMPs can cause arterial wall destruction. MMP-3 may play role in the pathogenesis of coronary aneurysm development through increased proteolysis of extracellular matrix proteins.

Decreased plasminogen activator inhibitor-1 levels in coronary artery aneurysmatic patients.

Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of arterial aneurysms through increased proteolysis of extracellular matrix proteins. Increased proteolysis due to elevated matrix degrading enzyme activity in the arterial wall may act as a susceptibility factor for the development of coronary aneurysms. Plasmin strongly stimulates pro-MMP enzyme conversion to the active form. Plasmin hyperactivity due to decreased plasminogen activator inhibitor-1 (PAI-1) may cause MMP over activity and coronary aneurysms. The aim of this study was to investigate the association between PAI-1 and presence of coronary aneurysms. Twenty-three patients with aneurysmal coronary artery disease and stable angina were enrolled into study (Group 1). Twenty-two patients without coronary aneurysm were selected as a control group (Group 2). PAI-1 was measured in peripheral venous blood. The plasma PAI-1 level was lower in the coronary artery aneurysmatic patients compared to the control group (8.41 +/- 4.28 vs. 13.32 +/- 10.05 ng/ml, p = 0.037). Serum C-reactive protein (CRP) values were not significantly different between groups (3.83 +/- 1.08 vs. 4.01 +/- 1.35 mg/l, p >0.05). Increased matrix degrading enzyme activity can cause arterial wall destruction through increased proteolysis of extracellular matrix proteins. Unregulated plasmin hyperactivity due to decreased inhibition by PAI-1 may play an important role in coronary aneurysm formation.

Decidualization induces the expression and activation of an extracellular protease neuropsin in mouse uterus.

Uterine decidualization is accompanied by the remodeling of the cell-matrix and cell-cell interactions around the endometrial stromal cells to allow an appropriate invasion of trophoblasts. This remodeling is thought to require the proteolysis of extracellular matrix proteins or cell adhesion molecules; however, the molecular mechanism remains poorly understood. In this study, decidualization induced the expression and activation of an extracellular serine protease neuropsin in the mouse uterus. Although nonpregnant uteri contained little neuropsin, the protein content and enzymatic activity increased markedly and peaked at the midgestational period in pregnant uteri. Neuropsin expression and activity was also upregulated in artificially induced deciduomata but not in nondecidualized pseudopregnant uteri. Neuropsin is the first extracellular protease to show the evident induction of expression and activity by decidualization and might contribute to the remodeling of extracellular components after decidualization.

Polymorphisms in the promoter regions of MMP-2, MMP-3, MMP-9 and MMP-12 genes as determinants of aneurysmal coronary artery disease.

Our hypothesis was that functional polymorphisms in matrix metalloproteinase (MMP) genes may act as susceptibility factors for the development of coronary aneurysms (CAs). Different forms of remodeling have been described at the level of coronary arteries; CA, reported in 1% to 5% of patients with angiographic evidence of coronary artery disease (CAD), are one of them. Matrix metalloproteinases have been implicated in the pathogenesis of aneurysm development through increased proteolysis of extracellular matrix proteins. We screened 3,862 patients who underwent coronary angiography and identified 113 patients with CAD with at least one CA (CA group); these patients were matched with 226 patients with CAD without CA (control group). The -1,306 C/T MMP-2, 5A/6A MMP-3, CA-repeat MMP-9 and -82 A/G MMP-12 polymorphisms were determined. The MMP-2, MMP-9 and MMP-12 polymorphisms were not associated with CA. By contrast, the 5A/5A genotype of MMP-3 was significantly more frequent in the CA group than in the control group (31% vs. 18%, p = 0.015); similarly, the MMP-3 5A allele was more frequent in the CA group (p = 0.009). Three variables were independently associated with CA: the MMP-3 5A/5A genotype (odds ratio [OR] = 2.23, 95% confidence interval [CI] [1.27 to 3.93]), a previous myocardial infarction (OR = 1.91, 95% CI [1.14 to 3.20]) and a history of aortic aneurysm (OR = 21.06, 95% CI [2.35 to 188]). The MMP-3 5A allele is associated with the occurrence of CA. Our results suggest that an increased proteolysis in the arterial wall may act as a susceptibility factor for the development of CA in patients with coronary atherosclerosis.

Potentiation by hypercholesterolemia of the induction of aortic intramural synthesis of plasminogen activator inhibitor type 1 by endothelial injury.

Accumulation of plasminogen activator inhibitor type 1 (PAI-1) in the arterial wall may accelerate atherogenesis by inhibiting fibrinolysis, diminishing proteolysis of extracellular matrix proteins, or modifying migration of vascular smooth muscle cells. Increased intramural expression of the PAI-1 gene is induced by thrombosis. To determine whether it occurs also in response to a sustained mechanical insult to endothelium, hypercholesterolemia, or both, rabbits were subjected to sustained aortic injury induced by implantation of indwelling polyethylene tubing, to hyperlipidemia induced by cholesterol and peanut oil feeding over a period of 8 weeks, or both. Sustained vascular injury alone did not increase plasma PAI-1. However, hypercholesterolemia with or without mechanically induced vascular injury increased plasma PAI-1 twofold. The expression of PAI-1 mRNA in aorta (Northern blots) was significantly increased when vascular injury was combined with hyperlipidemia. In situ hybridization showed that the increase with mechanical injury alone occurred in endothelial cells covering the neointima (positive for factor VIII and thrombomodulin), in abnormally differentiated vascular smooth muscle cells (positive for embryonic myosin heavy chain), and in macrophages (positive for the RAM-11 anti-macrophage antibody). Qualitatively similar but much more marked increases in PAI-1 gene expression were seen when arterial injury was accompanied by hypercholesterolemia. Neither vitronectin, known to stabilize PAI-1, nor vitronectin mRNA increased in liver. However, immunocytochemistry and Western blots demonstrated marked aortic accumulation of vitronectin protein with hyperlipidemia, particularly in subendothelial fibrotic regions, accompanied by increased neointimal vitronectin mRNA as shown by in situ hybridization. These results suggest that increased synthesis and stabilization of vascular PAI-1 may potentiate accumulation of extracellular matrix, thereby accelerating atherosclerosis.