Activity of Antioxidant Enzymes in the Regional Blood Flow during Pelvic Venous Disorders in Women.

Activity of some antioxidant enzymes (superoxide dismutase, catalase, and glutathionedependent enzymes), as well as the level of LPO products in the region regional blood flow (collateral branches of the main trunks of ovarian veins) in women with pelvic venous disorders were studied. A compensatory increase in activity of superoxide dismutase, catalase, and glutathione peroxidase during stage I of the disease was found; during stage II, superoxide dismutase activity decreased and glutathione peroxidase increased, while during stage III, pronounced decrease in activities of all studied enzymes was observed. The level of lipid peroxidation products in the regional blood flow increased as the disease progressed, with maximum values in the third stage.

Estrogen and estrogen receptor affects MMP2 and MMP9 expression through classical ER pathway and promotes migration of lower venous vascular smooth muscle cells.

OBJECTIVE: To explore the role of estrogen and estrogen receptors in the migration of vascular smooth muscle cells in varicose lower-extremity veins. PATIENTS AND METHODS: Tissue samples of normal lower extremity vein (56 cases) and varicose lower extremity vein (47 cases) were collected. Western blot and real-time fluorescent qPCR were performed to measure the expression of Estrogen receptor α (ERα) in tissues. Two cell co-culture systems were established for human umbilical vein endothelial cells (HUVECs) and human umbilical vein smooth muscle cells (HUVSMCs). One system was incubated under normal oxygen conditions (normal oxygen group), and the other was under oxygen-poor conditions (hypoxia group). The two systems were treated with 10-7 mM Estrogen E2, 10-7 mM BSA-conjugated Estrogen E2-BSA, 10-7 mM Estrogen E2+10-3 mM Tamoxifen (TAM), respectively for 24 h. The treated cells were subjected to cell scratch assay, transwell assay, and Western blot analysis of MMP2 and MMP9 protein expression. RESULTS: The expression of ERα in varicose lower extremity vein was significantly up-regulated compared with that in normal lower extremity vein. The cell migration rate and the number of migrating cells in untreated hypoxia group and E2-treated normal oxygen group were comparable (p>0.05) to those in untreated normal oxygen group. The cell migration rate and the number of migrating cells were significantly increased (p<0.05) in E2-treated hypoxia group, compared with E2-treated normal oxygen group and untreated hypoxia group. The cell migration rate, the number of migrating cells, and expression levels of MMP2 and MMP9 were significantly decreased in E2/TAM-treated hypoxia group, compared with those in E2-treated hypoxia group. CONCLUSIONS: In summary, E2 can promote the migration of vascular smooth muscle cells and induce varicose veins of the lower extremities, which may be related to the promotion of MMP2 and MMP9 expression through the classical pathway of ER.

Sulodexide Improves Contraction and Decreases Matrix Metalloproteinase-2 and -9 in Veins Under Prolonged Stretch.

High pressure in the lower-limb veins is often associated with chronic venous insufficiency and varicose veins (VVs), making it important to search for the mechanisms and agents that control venous function. We have shown that protracted increases in venous stretch/wall tension reduce vein contraction and augment matrix metalloproteinase (MMP)-2 and -9. Also, MMP-2 and MMP-9 promote venodilation, a hallmark of VVs. Sulodexide (SDX) is a blend of glycosaminoglycans with efficient profibrinolysis and antithrombosis activities, but its actions on vein function and the mechanisms involved are unclear. We tested the hypothesis that SDX enhances venous contractile response by decreasing MMP expression/activity in veins subjected to protracted stretch. Rat inferior vena cava (IVC) rings were treated with SDX (0.001-1 mg/mL) or vehicle, equilibrated under control 0.5-g resting tension or protracted 2-g stretch for 18 hours, and the contractile response to 96-mM KCl and phenylephrine (Phe) in SDX-treated and nontreated veins was recorded. In IVC rings under control 0.5-g resting tension, SDX caused dose-dependent contraction, 96-mM KCl caused marked contraction (176-mg/mg tissue), and Phe caused dose-dependent contraction with a maximum (56-mg/mg tissue) at 10 M. In IVC subjected to protracted 2-g stretch, 96-mM KCl-induced contraction was reduced to 112 mg/mg and maximal Phe-induced contraction was decreased to 23 mg/mg. In IVC subjected to protracted 2-g stretch plus SDX, 96-mM KCl-induced contraction was restored to 228 mg/mg and maximal Phe-induced contraction was improved to 115 mg/mg. Gelatin zymography and Western blots revealed increases in MMP-2 and MMP-9 levels/gelatinolytic activity in veins subjected to protracted 2-g stretch and reversal to control levels in veins subjected to 2-g stretch plus SDX. Thus, SDX improves vein function and augments the contractile response in veins subjected to protracted stretch. The SDX-induced improvement of contraction and restoration of vein function appear to involve decreases in MMP-2 and MMP-9 and may contribute to the benefits of SDX in chronic venous insufficiency and VVs.

Effect of a Peptide Construct on Differentiated Macrophage MMP-2 and MMP-9 Levels of Varicose Patients.

BACKGROUND: The Matrix Metalloproteinase (MMPs) secreted from macrophages can affect the extracellular matrix remodeling process and improve varicose veins. AIM: The aim of this study was to investigate the MMP-2 and MMP-9 gene expression and activity levels in the differentiated macrophages M2 of subjects with varicose veins, and to evaluate a peptide construct on their catalytic functions. METHODS: The macrophages were differentiated from the monocytes using M-CSF. The MMP-2 and MMP-9 gene expression and activity levels were measured by RT-qPCR and Zymography techniques, respectively. A peptide construct (ESLCG) was predicted with bioinformatics tools, and was prepared for the study of enzyme functions as compared to Batimastat. Furthermore, the docking studies were obtained for the evaluation of interactions between peptide construct, Batimastat and enzyme 3D structures. RESULTS: The results showed significant increases in MMP2 and MMP9 gene expression levels (P<0.001 and P<0.004, respectively) and gelatinolytic activities (P<0.001 and P<0.0001, respectively) in the macrophages. In agreement with the inhibitory effects of Batimastat, the peptide construct inhibited the MMP-2 and MMP-9 gelatinolytic activities up to 6.8 and 6.5 folds in the concentration of 150 µM. The docking analyses showed that the Lys187, Arg98, Leu49, Gly189, Leu190, Met97, Tyr53 and Phe57 residues of MMP-2 and the Leu187, His190, Glu402, His401, His405 and His411 residues of MMP-9 are interacted with the atoms of Batimastat and ESLCG peptide. CONCLUSION: The ESLCG peptide may be applied as an inhibitor of MMP-2 and MMP-9 enzymes in the subjects with varicose veins.

Associations between miR-661, miR-1202, lncRNA-HOTAIR, lncRNA-GAS5 and MMP9 in differentiated M2-macrophages of patients with varicose veins.

BACKGROUND: The venous hypertension is suggested as the main cause of varicose disease. Some mediators and growth factors are known as the responsible of cellular events for the progression of venous perturbations. The aim of this study was to investigate non-coding (nc) RNA and MMP9 expression levels in macrophages differentiated from monocytes of patients with varicose veins. METHODS: The monocytes were isolated from the whole blood samples by RosetteSep kit and were differentiated to macrophages M2 using M-CSF factor. The based on ncRNA-gene network, lncRNA-GAS5, lncRNA-HOTAIR, miRNA-661, miRNA-1202, and MMP9 were selected. The gene expression levels were measured by RT-qPCR technique. RESULTS: Data showed that the MMP9 gene expression increased (P=0.003) while the GAS5, miRNA-661, and miRNA-1202 expression levels reduced significantly in the differentiated macrophages of patients (P=0.035, P=0.009, and P=0.015, respectively). Furthermore, the MMP9 gene expression levels were conversely related to the GAS5, HOTAIR, miRNA-661 and miRNA-1202 expression levels. CONCLUSIONS: The results suggested that the lncRNA-GAS5, miRNA-661, miRNA-1202 and MMP9 are involved in varicose disease.

Matrix Metalloproteinases in Remodeling of Lower Extremity Veins and Chronic Venous Disease.

The veins of the lower extremity are equipped with efficient wall, contractile vascular smooth muscle (VSM), and competent valves in order to withstand the high venous hydrostatic pressure in the lower limb and allow unidirectional movement of deoxygenated blood toward the heart. The vein wall structure and function are in part regulated by matrix metalloproteinases (MMPs). MMPs are zinc-dependent endopeptidases that are secreted as inactive pro-MMPs by different cells in the venous wall including fibroblasts, VSM, and leukocytes. Pro-MMPs are activated by other MMPs, proteinases, and other endogenous and exogenous activators. MMPs degrade various extracellular matrix (ECM) proteins including collagen and elastin, and could affect other cellular processes including endothelium-mediated dilation, VSM cell migration, and proliferation as well as modulation of Ca2+ signaling and contraction in VSM. It is thought that increased lower limb venous hydrostatic pressure increases hypoxia-inducible factors and other MMP inducers such as extracellular matrix metalloproteinase inducer, leading to increased MMP expression/activity, ECM protein degradation, vein wall relaxation, and venous dilation. Vein wall inflammation and leukocyte infiltration cause additional increases in MMPs, and further vein wall dilation and valve degradation, that could lead to chronic venous disease and varicose veins (VVs). VVs are often presented as vein wall dilation and tortuosity, incompetent venous valves, and venous reflux. Different regions of VVs show different MMP levels and ECM proteins with atrophic regions showing high MMP levels/activity and little ECM compared to hypertrophic regions with little or inactive MMPs and abundant ECM. Treatment of VVs includes compression stockings, venotonics, sclerotherapy, or surgical removal. However, these approaches do not treat the cause of VVs, and other lines of treatment may be needed. Modulation of endogenous tissue inhibitors of metalloproteinases (TIMPs), and exogenous synthetic MMP inhibitors may provide new approaches in the management of VVs.

Morphology and Progression in Primary Varicose Vein Disorder Due to 677C>T and 1298A>C Variants of MTHFR.

BACKGROUND: Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T. METHODS: We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autologous vein reconstruction for arterial occlusive disease as controls. We compared the frequencies of c.677C>T and another polymorphism of MTHFR, c.1298A>C, with morphology and types of complicated disease. Morphology was recorded as a trunk or perforator type and peripheral congestive complication was defined as chronic venous insufficiency (CEAP C3-6) associated with edema and skin manifestations. FINDINGS: Multivariate analysis of genotypes for c.677C>T and c.1298A>C indicated that c.677C>T was associated significantly with the trunk phenotype (43/53 patients, 81%, p < 0.01), while c.1298A>C was associated significantly with the perforator phenotype (18/24 patients, 75%, p < 0.01) of primary varicose veins. Accordingly, when both c.677C>T and c.1298A>C displayed a heterozygous genotype, the patients were more likely to present with both phenotypes. Additionally, c.1298A>C was found to be strongly linked to the congestive complication (34/51 patients, 67%, p < 0.01). INTERPRETATION: Both polymorphisms of MTHFR may be involved in the morphological specification of primary varicose veins and contribute to the development of complicated disease. FUNDING: None.

Bortezomib protects from varicose-like venous remodeling.

Despite the high prevalence of venous diseases that are associated with and based on the structural reorganization of the venous vessel wall, not much is known about their mechanistic causes. In this context, we demonstrated that the quantity of myocardin, a transcriptional regulator of the contractile and quiescent smooth muscle cell phenotype, was diminished in proliferating synthetic venous smooth muscle cells (VSMCs) of human and mouse varicose veins by 51 and 60%, respectively. On the basis of the relevance of proteasomal activity for such phenotypic changes, we hypothesized that the observed VSMC activation is attenuated by the proteasome inhibitor bortezomib. This drug fully abolished VSMC proliferation and loss of myocardin in perfused mouse veins and blocked VSMC invasion in collagen gels by almost 80%. In line with this, topical transdermal treatment with bortezomib diminished VSMC proliferation by 80%, rescued 90% of VSMC myocardin abundance, and inhibited varicose-like venous remodeling by 67 to 72% in a mouse model. Collectively, our data indicate that the proteasome plays a pivotal role in VSMC phenotype changes during venous remodeling processes. Its inhibition protects from varicose-like vein remodeling in mice and may thus serve as a putative therapeutic strategy to treat human varicose veins.

Increased levels of lysosomal cysteinyl cathepsins in human varicose veins: a histology study.

Varicose veins are a major chronic venous disease characterised by extensive remodelling of the extracellular matrix architecture in the vascular wall. Although matrix metalloproteinases have been implicated in these pathologic events, little is known about the functional relevance of other protease family members. Here, we studied the distribution of lysosomal cysteine proteases, cathepsins B, L, K, and S, and their endogenous inhibitor, cystatin C, in long saphenous vein specimens from nine normal donors and 18 patients with varicose veins (VVs). Immunohistochemical analysis demonstrated increased levels of cathepsins L, K, B, and S and reduced levels of cystatin C in VVs. This imbalance between cysteinyl cathepsins and cystatin C may favour VV remodelling. To investigate the inflammatory mechanism of their expression, we examined a detailed inflammatory cell profile in VVs, including macrophages, T lymphocytes, and mast cells. Increased numbers of CD3-positive T cells and tryptase-positive mast cells were found in VVs, and enhanced levels of cysteinyl cathepsins were detected from lesion CD3-positive T cells, chymase-positive mast cells, endothelial cells, and smooth-muscle cells. Elevated cathepsins, and their co-localisation to infiltrated inflammatory cells and to vascular cells, suggest that these proteases participate in extracellular matrix degradation in response to inflammation during VV pathogenesis.

Matrix metalloproteinases as potential targets in the venous dilation associated with varicose veins.

Varicose veins (VVs) are a common venous disease of the lower extremity characterized by incompetent valves, venous reflux, and dilated and tortuous veins. If untreated, VVs could lead to venous thrombosis, thrombophlebitis and chronic venous leg ulcers. Various genetic, hormonal and environmental factors may lead to structural changes in the vein valves and make them incompetent, leading to venous reflux, increased venous pressure and vein wall dilation. Prolonged increases in venous pressure and vein wall tension are thought to increase the expression/activity of matrix metalloproteinases (MMPs). Members of the MMPs family include collagenases, gelatinases, stromelysins, matrilysins, membrane- type MMPs and others. MMPs are known to degrade various components of the extracellular matrix (ECM). MMPs may also affect the endothelium and vascular smooth muscle, causing changes in the vein relaxation and contraction mechanisms. Endothelial cell injury also triggers leukocyte infiltration, activation and inflammation, which lead to further vein wall damage. The vein wall dilation and valve dysfunction, and the MMP activation and superimposed inflammation and fibrosis would lead to progressive venous dilation and VVs formation. Surgical ablation is an effective treatment for VVs, but may be associated with high recurrence rate, and other less invasive approaches that target the cause of the disease are needed. MMP inhibitors including endogenous tissue inhibitors (TIMPs) and pharmacological inhibitors such as zinc chelators, doxycycline, batimastat and marimastat, have been used as diagnostic and therapeutic tools in cancer, autoimmune and cardiovascular disease. However, MMP inhibitors may have side effects especially on the musculoskeletal system. With the advent of new genetic and pharmacological tools, specific MMP inhibitors with fewer undesirable effects could be useful to retard the progression and prevent the recurrence of VVs.

Abnormal expression of Tie1 on the valves of great saphenous varicose vein.

OBJECTIVE: To investigate the abnormal expressions of Tie1 on the valves of great saphenous varicose vein, and to discuss the relationship between the phenomenon and pathogenesis of varicose vein of lower extremity. METHODS: Varicose veins group 18 samples, normal control group 14 samples. Immunohistochemistry staining has investigated the expression of CD31 and Tie1 in the first valves of great saphenous veins. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) has checked mRNA expression of Tie1. Western blot has checked the expression of Tie1 protein in venous valves. RESULTS: In normal control group valves, there was no difference between proximal and distal sides endothelium, which expressing CD31 in both valvar basement and valve cusp (positive endothelial cells [ECs] percentage: P > 0.05, P > 0.05). However, the endothelium of the proximal side demonstrates Tie1 stronger than distal side in valvar basement (positive ECs percentage: P < 0.05), which was not found at valve cusp (positive ECs percentage: P > 0.05). In varicose veins group, the endothelium of proximal side cells expresses CD31 weaker than distal side at both valvar basement and valve cusp (positive ECs percentage: P < 0.05, P < 0.05) besides the morphological alteration of valves. Moreover, it expresses Tie1 much weaker than diatal side (positive ECs percentage: P < 0.01). Semi-quantitative RT-PCR showed that valves of varicose veins group expressed Tie1 much weaker than the normal control group (P < 0.01). Western blot could not detect the expression of Tie1 in venous valves. CONCLUSION: The decreasing expression of Tie1 may play an important role in the pathogenesis of primary lower extremity varicose veins.

Prolidase enzyme activity in varicose venous walls related to sperm count in patients with varicocele.

OBJECTIVES: To investigate peripheral, seminal and varicose venous wall prolidase enzyme activities and their relationships between sperm parameters in patients with varicocele. DESIGN AND METHODS: Prolidase enzyme activities were determined in blood, seminal fluid and varicose vein walls in patients with grade 3 varicocele. Sperm parameters were also measured and the relationships between prolidase enzyme and sperm parameters were assessed by statistical correlation analysis. RESULTS: There was a significant and negative correlation between sperm counts and varicose venous wall prolidase enzyme activities (r = -0.618, p < 0.001) and a positive significant correlation between sperm counts and seminal fluid prolidase enzyme activities (r = 0.676, p < 0.001). None of the parameters were correlated with sperm motility indices. CONCLUSION: Varicose venous wall prolidase enzyme activity could be an important factor in progression of azoospermia and infertility in patients with varicocele.

Mechanisms of increased vascular superoxide production in human varicose veins.

INTRODUCTION: Varicose vein disease is one of the most common morbidities in the developed countries. Recent studies have shown that oxidative stress is increased in varicose veins (VV) and venous insufficiency. However, the exact mechanisms of oxidative stress in VV remain unknown. OBJECTIVES: The aim of the study was to measure superoxide anion production and analyze its enzymatic sources in VV in comparison with control human saphenous veins (HSV). Superoxide production was also compared between the proximal and distal segments of the veins. PATIENTS AND METHODS: Proximal and distal segments of varicose veins (14 patients, aged 52 ±3.5 years) and control veins (15 patients, aged 56 ±4 years) were obtained during VV removal or elective coronary artery bypass graft surgery, respectively. Subjects were matched for age, sex, and the major risk factors for atherosclerosis. Superoxide was measured by lucigenin-enhanced chemiluminescence (5 µmol/l) in the presence and absence of oxidase inhibitors. RESULTS: Superoxide production was increased in VV compared with control HSV. This increase was particularly evident in the distal segments of VV. There was a significant correlation between superoxide production in the proximal and distal segments of HSV but not of VV. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and uncoupled nitric oxide synthase (NOS) were the major sources of superoxide in VV, because their inhibitors greatly attenuated superoxide production in VV. CONCLUSIONS: NADPH oxidases and NOS could represent valuable drug targets for pharmacological treatment and prevention of varicose vein disease. Oxidative stress may provide a link between endothelial dysfunction, inflammation, and immune activation and the development of chronic venous dysfunction.

MMP2 gene polymorphisms and MMP2 mRNA levels in patients with superficial varices of lower extremities.

BACKGROUND: Although superficial varices of lower extremities with high morbidity are common, their etiology has not been elucidated yet. Previously, it was thought that venous hypertension was responsible for such cases by causing valvular insufficiency, but recent findings indicate that the changes in the venous wall structure might be main initiating factors. Matrix metalloproteinase enzyme-2 (MMP2) is one of the enzymes known to have functions in remodelling of the extracellular matrix mainly in vascular structures. MATERIALS AND METHODS: We studied two functional gene polymorphisms in -735 and -1306 regions of matrix metalloproteinase enzyme-2 (MMP2) gene, and their effects on mRNA expression of MMP2. We used a previously defined (PCR-RFLP) method for polymorphism analyses. RESULTS: CC genotype and C allele for MMP2 -735 gene region were more common in the control group and there was no significant difference between groups for MMP2 - 1306 gene polymorphisms. MMP2 mRNA levels were higher in the group that had both varices and coronary artery disease (CAD). CONCLUSION: There was no significant effect of MMP2 polymorphisms on mRNA expression. As MMP2 mRNA levels were higher in varices patients with CAD compared to the CAD only and varices only groups, it is necessary to make advanced researches to elucidate the relationship between CAD and varices.

Polymorphism of matrix metalloproteinase genes (MMP1 and MMP3) in patients with varicose veins.

BACKGROUND: Several risk factors for varicose veins have been identified: female gender, combined with obesity and pregnancy, occupations requiring standing for long periods, sedentary lifestyle, history of deep-vein thrombosis and family history. However, no specific gene variants related to a wide prevalence of varicosities in general population have been identified. Extracellular matrix composition, predominantly maintained by matrix metalloproteinases (MMPs), may affect the vein-wall structure, which may lead to dilation of vessels and cause varicosities. AIMS: MMP-1 (tissue collagenase I) and MMP-3 (stromelysin I) expression was found to be raised in varicose veins compared with normal vessels. Therefore, a study was conducted to evaluate a potential association between MMP1 and MMP3 promoter polymorphisms and a risk of varicose veins. METHODS: Genotyping for the presence of the polymorphisms -1607dupG (rs1799750) in MMP1 and -1171dupA (rs3025058) in the MMP3 promoter region was performed using PCR and restriction-fragment length polymorphism assays in a group of 109 patients diagnosed with varicose veins and 112 healthy controls. RESULTS: The frequencies of the MMP1 and MMP3 alleles (minor allele frequency 0.440 in patients vs. 0.451 in the controls for MMP1-1607*G and 0.514 vs. 0.469 for MMP3-1171*dupA, respectively) and of genotypes did not differ significantly between patients and controls. CONCLUSIONS: The MMP1-1607dupG and MMP3-1171dupA promoter polymorphisms are not valuable markers of susceptibility for varicose veins.

Glycosaminoglycan-degrading enzymes in the varicose vein wall.

AIM: Mechanical properties of the vein wall are determined by extracellular matrix components, including glycosaminoglycans (GAGs). The aim of the study was to evaluate the activity of enzymes involved in GAGs degradation pathway in the wall of varicose veins and varicose veins complicated by thrombophlebitis, when compared to the wall of normal ones. METHODS: Normal, varicose veins and varicose veins complicated by thrombophlebitis were collected during surgical treatment of 10 patients. Activities of endoglycosidases, sulphatases and exoglycosidases were assessed according to colorimetric methods. RESULTS: Activities of neutral endoglycosidases degrading chondroitin-4-sulphate (C4S) and heparan sulphate (HS) were decreased, whereas activities of neutral endoglycosidases degrading dermatan sulphate and hyaluronic acid were increased in varicose veins and varicose veins complicated by thrombophlebitis. Activities of acidic endoglycosidases degrading C4S and HS were decreased in varicose veins and varicose veins complicated by thrombophlebitis, whereas activity of acidic endoglycosidases degrading chondroitin-6-sulphate was decreased only in varicose veins complicated by thrombophlebitis. Furthermore increased activities of arylosulphatase B, beta-N-acetylhexosaminidase and alpha-L-iduronidase were demonstrated in varicose veins, as well as in varicose veins complicated by thrombophlebitis. CONCLUSIONS: Changed activities of GAGs-degrading enzymes may contribute to previously reported changes in the content and molecular differentiation of GAGs in the wall of varicose veins that may play a role in the disease pathogenesis.

Metalloproteinase expression in venous aneurysms.

INTRODUCTION: Although recognized with increasing frequency, the pathogenesis of venous aneurysms (VA) remains poorly understood. We evaluated 8 patients with 10 VA for the presence, localization and activity of metalloproteinases (MMPs). METHODS: Tissue specimens from VA (n=8), normal saphenous vein (NSV n=7) and varicose veins (VV n=7 were compared by histology and immunohistochemistry (IHC). Histologic sections were stained with H&E, Movats pentachrome and toluidine blue, and IHC specimens with antibodies to CD68, MMP2, MMP9, and MMP13. Protein expression and enzyme activity were determined by Western immunoblotting and zymography. RESULTS: Three of 4 patients with popliteal VA presented with edema and leg pain and the remaining patient with deep venous thrombosis (DVT) and pulmonary embolism (PE). The 5 popliteal VA were treated by; excision and reanastomosis (n=2) lateral venorrhaphy (n=2) and spiral saphenous vein graft (n=1). The 3 patients with 4 upper extremity VA had discomfort over a compressible mass. Two of the VA were excised and the remaining patients aneurysm ruptured spontaneously. The mesenteric VA, an incidental finding at laparotomy was excised. Thrombus was present in 2 popliteal, 1 upper extremity and in the mesenteric aneurysm. Histologically, VA and VV were characterized by fragmentation of the elastic lamellae, loss of smooth muscle cells (SMCs) and attenuation of the venous wall when compared to NSV. Varicose veins and VA also demonstrated increased expression of MMP-2, MMP-9 and MMP-13 in endothelial cells (ECs), SMCs and adventitial microvessels compared to NSV. Both pro-MMP-2 and pro-MMP-9 were detected by zymography in VA,VV and NSV but only MMP-2 activity was demonstrable. CONCLUSIONS: The structural changes in the venous wall in addition to the increased expression of MMP-2, MMP-9 and MMP-13 in VA compared to NSV and VV suggests a possible causal role for these MMPs in their pathogenesis.

Matrix metalloproteinases in venous tissue remodeling and varicose vein formation.

Matrix metalloproteinases (MMPs) play a major role in extracellular matrix (ECM) turnover under both physiological and pathological conditions. Studies on venous tissues from experimental animals and humans identified several MMP subtypes, and showed significant changes in the expression and activity of specific MMPs during vein wall remodeling. Also, significant research has focused on the role of MMPs in chronic venous disease (CVD) and varicose vein formation in the lower extremities and their progression to thrombophlebitis and venous leg ulcer. Several hypotheses have been forwarded regarding the pathophysiological mechanisms underlying the relation between MMPs and the formation, progression and complications of varicose veins. The effects of MMPs on ECM degradation could result in significant venous tissue remodeling and degenerative and structural changes in the vein wall, leading to venous dilation and valve dysfunction. MMPs may also induce early changes in the endothelium and venous smooth muscle function in the absence of significant ECM degradation or structural changes in the vein wall. In addition, evidence suggests increased activity of MMPs in the advanced stages of chronic venous insufficiency (CVI) associated with skin changes and leg ulceration as well as in the wound fluid environment. Several pharmacological therapies and surgical strategies are being utilized in the management of varicose veins, with variable success and recurrence rates. Inhibition of MMPs may represent a novel therapeutic intervention to limit the progression of varicose veins to CVI and leg ulceration.

Matrix metalloproteinases and their inhibitors in vascular remodeling and vascular disease.

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade various components of the extracellular matrix (ECM). Members of the MMP family include collagenases, gelatinases, stromelysins, matrilysins and membrane-type MMPs. ProMMPs are cleaved into active forms that promote degradation of ECM proteins. Also, recent evidence suggests direct or indirect effects of MMPs on ion channels in the endothelium and vascular smooth muscle, and on other mechanisms of vascular relaxation/contraction. Endogenous tissue inhibitors of metalloproteinases (TIMPs) reduce excessive proteolytic ECM degradation by MMPs. The balance between MMPs and TIMPs plays a major role in vascular remodeling, angiogenesis, and the uterine and systemic vasodilation during normal pregnancy. An imbalance in the MMPs/TIMPs activity ratio may underlie the pathogenesis of vascular diseases such as abdominal aortic aneurysm, varicose veins, hypertension and preeclampsia. Downregulation of MMPs using genetic manipulations of endogenous TIMPs, or synthetic pharmacological inhibitors such as BB-94 (Batimastat) and doxycycline, and Ro-28-2653, a more specific inhibitor of gelatinases and membrane type 1-MMP, could be beneficial in reducing the MMP-mediated vascular dysfunction and the progressive vessel wall damage associated with vascular disease.