Reduced Glomerular Endothelial Thrombomodulin Is Associated with Glomerular Macrophage Infiltration in Diabetic Nephropathy.

The endothelial glycoprotein thrombomodulin regulates coagulation, inflammation, and apoptosis. In diabetic mice, reduced thrombomodulin function results in diabetic nephropathy (DN). Furthermore, thrombomodulin treatment reduces renal inflammation and fibrosis. Herein, thrombomodulin expression was examined in human kidney samples to investigate the possibility of targeting thrombomodulin in patients with DN. Glomerular thrombomodulin was analyzed together with the number of glomerular macrophages in 90 autopsied diabetic cases with DN, 55 autopsied diabetic cases without DN, and 37 autopsied cases without diabetes or kidney disease. Thrombomodulin mRNA was measured in glomeruli microdissected from renal biopsies from patients with DN and nondiabetic controls. Finally, glomerular thrombomodulin was measured in diabetic mice following treatment with the selective endothelin A receptor (ETAR) blocker, atrasentan. In diabetic patients, glomerular thrombomodulin expression was increased at the mRNA level, but decreased at the protein level, compared with nondiabetic controls. Reduced glomerular thrombomodulin was associated with an increased glomerular influx of macrophages. Blocking the ETAR with atrasentan restored glomerular thrombomodulin protein levels in diabetic mice to normal levels. The reduction in glomerular thrombomodulin in diabetes likely serves as an early proinflammatory step in the pathogenesis of DN. Thrombomodulin protein may be cleaved under diabetic conditions, leading to a compensatory increase in transcription. The nephroprotective effects of ETAR antagonists in diabetic patients may be attributed to the restoration of glomerular thrombomodulin.

Does administration of eicosapentaenoic acid increase soluble thrombomodulin level in statin-treated patients with stable coronary artery disease?

Interventions targeting the serum eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio could be useful for the prevention of coronary artery disease (CAD). Few data exist regarding the effects of administration of EPA on the serum levels of soluble thrombomodulin (sTM) as a marker of endothelial damage, or on the relationship between the sTM and EPA/AA ratio in patients with CAD receiving statin treatment. We assigned stable CAD patients already receiving statin therapy to an EPA group (1800 mg/day: n = 50) or control group (n = 50). A significant increase of the sTM level was observed in the EPA group as compared to that in the control group 0.40 (0.10/0.70) FU/mL vs. 0.20 (0/0.40) FU/mL, p = 0.004 at the 6-month follow-up examination. Multivariate regression analysis after adjustments for coronary risk factors and changes of the serum lipid levels identified an increased EPA/AA ratio as an independent predictor of increased serum sTM level (ß = 0.244, p = 0.02). The results suggest that an increased sTM level caused by additional administration of EPA to statin might be associated with an increased EPA/AA ratio. The increase of the serum sTM after administration of EPA might reflect an increase of the TM expression on the endothelial surface rather than endothelial damage in CAD patients under statin treatment.Clinical Trial Registration Information UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000010452.

A key role for Toll-like receptor-3 in disrupting the hemostasis balance on endothelial cells.

Various virus infections cause dysfunctional hemostasis and in some instances lead to the development of viral hemorrhagic fever syndrome. How do diverse viruses induce the expression of tissue factor on vascular cells? We hypothesize that a direct stimulation of pattern recognition receptors (PRR) by viral nucleic acids may be the key. Double-stranded RNA (dsRNA) is produced by many viruses and is recognized by various PRR, including Toll-like receptor-3 (TLR3). We have investigated whether poly I:C, a model for viral dsRNA, can influence cellular hemostasis. Poly I:C could up-regulate tissue factor and down-regulate thrombomodulin expression on endothelial cells but not on monocytes. The response to poly I:C was diminished upon small interfering RNA (siRNA)-mediated inhibition of TLR3, but not other PRR. In vivo, application of poly I:C induced similar changes in the aortic endothelium of mice as determined by enface microscopy. D-dimer, a circulating marker for enhanced coagulation and fibrinolysis, and tissue fibrin deposition was elevated. All the hemostasis-related responses to poly I:C, but not cytokine secretion, were blunted in TLR3(-/-) mice. Hence, the activation of TLR3 can induce the procoagulant state in the endothelium, and this could be relevant for understanding the mechanisms of viral stimulation of hemostasis.

Paclitaxel potentiates inflammatory cytokine-induced prothrombotic molecules in endothelial cells.

To overcome the limitations of balloon expandible metal stent-induced neointimal smooth muscle cell proliferation, drug-coated stent devices have been developed. Drug eluting stents release high concentrations of antiproliferative agents, such as paclitaxel, to reduce neointimal hyperplasia. The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), is known to cause severe endothelial dysfunction and accelerate atherosclerotic lesion progression. The interaction of TNF-alpha and paclitaxel on the release of prothrombotic molecules was examined in endothelial cells. Treatment of endothelial cells with paclitaxel had no direct effect on tissue factor (TF) expression, but TNF-alpha increased TF. Cotreatment of paclitaxel with TNF-alpha markedly augmented the release of TF. TNF-alpha induced release of plasminogen activator inhibitor but no synergism occurred with paclitaxel. Treatment of endothelial cells with paclitaxel and TNF-alpha reduced expression of thrombomodulin and protein C receptor. Tissue factor pathway inhibitor expression was reduced by prolonged treatment with either paclitaxel or TNF-alpha. The adhesion molecule, CD62 E, was induced by TNF-alpha; however, CD31, CD62 P, and CD106 were not affected by paclitaxel and TNF-alpha. Apoptosis was not observed with cotreatment of endothelial cells with paclitaxel and TNF-alpha. CD59-positive microparticles were released in response to TNF-alpha, but the release was not augmented by paclitaxel. Paclitaxel and TNF-alpha increased the nitrotyrosination of proteins. These findings indicate that paclitaxel enhances TNF-alpha-induced release of TF, and downregulated thrombomodulin, increased protein nitration, which may subsequently favor prothrombotic intimal surface.

Degradation of vascular endothelial thrombomodulin by arginine- and lysine-specific cysteine proteases from Porphyromonas gingivalis.

BACKGROUND: The endothelial cell surface glycoprotein thrombomodulin (TM) inhibits vascular coagulation and inflammation via regulation of thrombin-mediated activation of protein C. Porphyromonas gingivalis is the major periodontopathic bacterium and has been found in vessel walls and atherosclerotic lesions in humans. P. gingivalis-derived cysteine proteases (gingipains) are known to enhance inflammatory and coagulant responses of vascular endothelial cells. However, it has not been elucidated whether gingipains affect vascular endothelial TM. METHODS: Purified arginine-specific gingipains (Rgps) and lysine-specific gingipain (Kgp) from P. gingivalis were used to investigate the effects of gingipains on recombinant human TM by immunoblot analyses. Flow cytometry and activated protein C assay were carried out to examine the effects of gingipains on vascular endothelial cell surface TM. Immunohistochemistry was performed to investigate TM expression in microvascular endothelia in gingival tissues taken from patients with periodontitis. RESULTS: Rgps and Kgp cleaved TM in vitro. Endothelial cell surface TM was also degraded by Rgps. Thrombin-mediated activation of protein C was reduced by Rgps through TM inactivation. Gingival microvascular endothelial TM was reduced in patients with periodontitis. CONCLUSIONS: P. gingivalis gingipains induced the degradation and inactivation of endothelial TM, which may promote vascular coagulation and inflammation. In addition, in vivo relevance was demonstrated by reduced expression of TM in gingival microvascular endothelia in patients with periodontitis, which may be involved in the pathogenesis of periodontitis.

A bacterial metabolite, trimethylamine N-oxide, disrupts the hemostasis balance in human primary endothelial cells but no coagulopathy in mice.

: The gut microbial metabolite, trimethylamine N-oxide (TMAO), was previously reported to induce platelet hypersensitivity, which leads to thrombotic risk. However, the molecular mechanism underlying the effects of TMAO on endothelial cells (EC), which is the primary vessel wall contact with the lumen, remains unclear. Here, we investigated the impact of TMAO on procoagulant activity (PCA) in EC and mice, for a possible link between microbiota and coagulation. To test the PCA of TMAO in EC, we performed one-stage clotting assays and converted into PCA. Antitissue factor (TF) antibody was used to test the TF role in PCA. Quantitative PCR was performed to measure the TF, thrombomodulin, IL-6, TF pathway inhibitor and IL-1b expressions at mRNA levels. To test the PCA and thrombotic risk by TMAO in mice, we challenged the mice with TMAO (8 mg/kg; 3 h) and measured the thrombin-anti-thrombin complex (TAT) and D-dimer levels as well as ferric chloride (FeCl3)-induced carotid artery thrombosis model. TMAO-induced TF expression in EC at mRNA and protein levels, dose-dependently. TF blocking experiment confirmed that the increased PCA by TMAO is TF-dependent. Also, mitogen-activated protein kinase pathway inhibitors abolished TMAO-induced TF expression. However, TMAO challenged mice failed to develop systemic activation of coagulation (TAT and D-dimer), as well as a FeCl3-induced carotid arterial thrombosis model. Our results indicated that TMAO triggered TF-dependent PCA via activation of nuclear factor-κB and downregulated thrombomodulin expression in human EC, but failed to develop systemic activation of coagulation in mice.

[The influence of simvastatin on hsCRP and some paramneters of hemostasis in patients with ischemic heart disease]. / Wplyw simwastatyny na hsCRP i wybrane parametry ukladu hemostazy u pacjentów z choroba niedokrwienna serca.

Inflammation and disturbances of the hemostatic system may play a role in pathogenesis and complications of ischemic heart disease. More and more reports indicate that apart from their cholesterol-lowering effect statins also exert other beneficial effects in cardiovascular diseases. Taking this into consideration, the aim of the study was to assess the influence of simvastatin (20 mg per day) on a marker of inflammation - CRP and some parameters of coagulation and fibrinolysis in 22 patients with ischaemic heart disease. Serum lipids, levels of hsCRP, thrombomodulin (TM), vWF, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), thrombin activatable fibrinolysis inhibitor (TAFI), t-PA, plasmin-antiplasmin complex (PAP) and TAFI activity were assessed before and after one, three and six months simvastatin treatment. After one month therapy of simvastatin, there have been significant reduction of levels of total cholesterol, LDL-cholesterol and triglycerides and these values have remained until the end of the study. No influence on the level of HDL-cholesterol has been observed. After 6 months of treatment significant decrease in the level of hsCRP and increase of the levels TM and vWF with reference to baselines results have been observed. After a 1-and 6-month therapy, the level of TAFI have been significantly increased. Other hemostatic parameters, i.e. levels of F1+2, TAT, t-PA, PAP and TAFI activity have not changed significantly. This prospective study has confirmed high efficacy of lipid-lowering effect and anti-inflammatory properties of simvastatin. Simvastatin influenced some hemo-static parameters, however, these effects were not, in majority, significant.

Plasma level of stromal derived factor-1 (SDF-1) is increased in disseminated intravascular coagulation patients who have poor outcomes: in vitro effect of SDF-1 on coagulopathy.

Stromal cell-derived factor-1 (SDF-1) is a CXC chemokine that activates and directs the migration of leukocytes that have CXCR4, which is the unique receptor for SDF-1. Although SDF-1/CXCR4 interaction has been implicated in various inflammatory conditions, its role in modulating coagulation has not been determined. We studied the plasma SDF-1 levels in 90 patients with suspected disseminated intravascular coagulation (DIC) and we found that circulating SDF-1 was significantly increased in the overt DIC patients and was also increased in overt DIC patients who have a poor outcome. We then tested in vitro whether SDF-1 can affect the expression of monocyte tissue factor (TF) and endothelial thrombomodulin (TM), and both of these play important roles in coagulopathy. SDF-1 did not affect the expression of surface TF protein and its function and the TF mRNA level in both monocytes and the monocytic leukemia cell line THP-1. SDF-1 also did not change the surface TM expression of endothelial cells. SDF-1 could enhance low-dose ADP induced platelet aggregation, although it failed by itself to induce aggregation. These findings suggest that plasma SDF-1 might be closely associated with hypercoagulability though its action as a platelet activator.

Salvianolic acid B modulates hemostasis properties of human umbilical vein endothelial cells.

Salviae miltiorrhizae (SM), a clinical, commonly used herb, can activate blood circulation and resolve stasis. We have investigated the effects of salvianolic acid B (Sal B), a pure compound extracted from the dried SM roots, on fibrinolytic (tissue-type plasminogen activator and plasminogen activator inhibitor, t-PA and PAI) and anticoagulant (thrombomodulin,TM) properties of cultured human umbilical vein endothelial cells (HUVECs). When HUVECs were treated with Sal B, a dose- (0.0125-0.5 mg/ml) and a time-dependent decrease in PAI activity were observed. PAI type 1 (PAI-1) antigen and PAI-1 mRNA expression significantly decreased compared to control values in the conditioned media of HUVECs pretreated with Sal B for 12 h. Moreover, TM activity reached a maximum stimulation of 1.25-fold over control levels in the pretreatment of Sal B for 12 h and t-PA and TM specific mRNA expression also increased (1.7- and 1.8-fold, respectively). In conclusion, Sal B increased the fibrinolytic and anticoagulant potential of cultured HUVECs by up-regulating the expression of t-PA and TM and by down-regulating the expression of PAI-1. These data suggest that Sal B is clinically effective because of its ability to change the gene expression profile of endothelial cells thereby preventing vascular events.

Increased plasma P-selectin and decreased thrombomodulin in pulmonary arterial hypertension were improved by continuous prostacyclin therapy.

BACKGROUND: Thrombosis in situ related to endothelial cell injury may contribute to the development of pulmonary hypertension (PH). P-selectin, a leukocyte adhesion receptor present in endothelial cells and platelets, reflects endothelial injury and platelet activation, and thrombomodulin (TM), a receptor for thrombin and a major anticoagulant proteoglycan on the endothelial membrane, reflects the anticoagulant activity of the endothelium. METHODS AND RESULTS: To assess abnormal coagulation due to endothelial injury in patients with PH, plasma levels of soluble P-selectin and TM were measured in 32 patients with primary PH (PPH), 25 with secondary pulmonary arterial hypertension (sPAH), 31 with pulmonary venous hypertension (PVH), and 17 healthy subjects (Control). These measurements were repeated after continuous infusion of prostacyclin in 15 patients with PPH and 3 with sPAH. P-selectin levels in both the sPAH and PPH groups were significantly higher than those in the Control and PVH groups (P<0.05). Plasma TM level in the PPH group was significantly lower than those in the other groups (P<0.01). After prostacyclin therapy, the lower TM level was increased and the higher P-selectin level was decreased (P<0.05). CONCLUSIONS: Decreased TM and increased P-selectin in PPH and sPAH may reflect in situ thrombosis due to endothelial injury. Prostacyclin may act not only as a vasodilator but also as an agent that improves endothelial injury and altered hemostasis in pulmonary arterial injury.

1alpha,25-dihydroxyvitamin D(3) and its potent synthetic analogs downregulate tissue factor and upregulate thrombomodulin expression in monocytic cells, counteracting the effects of tumor necrosis factor and oxidized LDL.

BACKGROUND: We have recently found that a hormonally active form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], exerts anticoagulant effects by upregulating the expression of an anticoagulant glycoprotein, thrombomodulin (TM), and downregulating the expression of a critical coagulation factor, tissue factor (TF), in monocytic cells including human peripheral monocytes. In this study, we investigated the counteracting effects of 1,25(OH)(2)D(3) and its potent analogs on TF induction and TM downregulation by tumor necrosis factor and oxidized LDL in monocytic cells and the modulatory effects of potent analogs on TF and TM expression. METHODS AND RESULTS: Effects of 1,25(OH)(2)D(3) and its potent synthetic analogs (22R)-22-methyl-20-epi-1,25(OH)(2)D(3) (KY3) and 22-oxacalcitriol on TF and TM antigen levels, cell surface activities, and mRNA levels in monocytic cells were examined. 1, 25(OH)(2)D(3) and its potent analogs showed anticoagulant effects in monocytic cells by downregulating TF and upregulating TM expression, counteracting the effects of tumor necrosis factor and oxidized LDL. KY3 was most potent in its regulatory effect on TF and TM expression. CONCLUSIONS: Because KY3 has the highest affinity for vitamin D receptor, our findings suggest that TF and TM regulation by 1, 25(OH)(2)D(3) analogs is also mediated by vitamin D receptor. The 1, 25(OH)(2)D(3) analogs KY3 and 22-oxacalcitriol may have the potential to serve as an agent for preventing and treating atherosclerotic and other cytokine-mediated thrombotic diseases and as a tool for studying the molecular mechanisms of TF and TM regulation.

Influence of long-term intervention with dietary counseling, long-chain n-3 fatty acid supplements, or both on circulating markers of endothelial activation in men with long-standing hyperlipidemia.

BACKGROUND: Dietary factors and very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) may influence the atherothrombotic process. Elevated concentrations of circulating cell adhesion molecules, thrombomodulin (TM), von Willebrand factor (vWF), and tissue-type plasminogen activator antigen (tPAag) are related to atherothrombotic cardiovascular disease. OBJECTIVE: The randomized Diet and Omega-3 Intervention Trial (DOIT) targeted a comparison of the effect of 3-y dietary counseling, n-3 PUFA supplementation (2.4 g/d), or both on circulating markers of endothelial activation. DESIGN: The study included 563 elderly men with long-standing hyperlipidemia. The men were randomly assigned by factorial design into 4 groups: control (no dietary counseling and placebo capsules), dietary counseling (and placebo capsules), n-3 PUFA supplementation (no dietary counseling), and dietary counseling and n-3 PUFA supplementation. RESULTS: Serum concentrations of fatty acids reflected good compliance. Dietary counseling was followed by significantly reduced concentrations of soluble intercellular adhesion molecule 1 (sICAM-1; P < 0.001), sTM (P = 0.004), and tPAag (P < 0.001) than in subjects without dietary counseling. After n-3 PUFA supplementation, significantly reduced concentrations of sICAM-1 (P < 0.001) and sTM (P = 0.006) were observed when compared with subjects receiving placebo capsules. An increase in tPAag was not significantly different from that observed in subjects receiving placebo capsules. For sICAM-1, a significant effect was observed for both interventions combined. CONCLUSIONS: Each intervention (dietary counseling or n-3 PUFA supplements) reduced sTM and sICAM-1 concentrations, indicating decreased endothelial activation. The tPAag increase in the groups not receiving dietary counseling (pooled), which indicates progression of atherosclerosis, was significantly counteracted by dietary counseling.

Effects of TNF-alpha and curcumin on the expression of thrombomodulin and endothelial protein C receptor in human endothelial cells.

The objective of this study was to elucidate the effects of tumor necrosis factor-alpha (TNF-alpha) on the expression of thrombomodulin (TM) and endothelial protein C receptor (EPCR) in human endothelial cells as well as the effect of curcumin, a spice and coloring food compound, as a potential therapeutic agent. Human umbilical vein endothelial cells (HUVECs) treated with TNF-alpha (2.0 ng/ml) showed reduced TM mRNA levels by 80%, 97%, 94%, and 97% at 3, 6, 12, and 24 h, respectively (P<0.05), by real-time PCR analysis. Dose-dependent study showed that TM mRNA levels of HUVECs were decreased by 86%, 89%, 91%, and 94% after treatment of TNF-alpha (0, 0.25, 0.5, 1, and 2 ng/ml) for 6 h, respectively (P<0.05). TM protein levels in HUVECs were significantly reduced by 69% in TNF-alpha-treated cells as compared to controls (P<0.05) by Western blot analysis. Secreted protein and activity of TM of HUVEC cultures were also significantly reduced in TNF-alpha-treated cells. In addition, EPCR mRNA levels of HUVECs were significantly reduced in TNF-alpha-treated group as compared to controls (P<0.05). Furthermore, these effects were observed in other types of endothelial cells from human coronary arteries, lung, and skin. Curcumin effectively blocked these effects of TNF-alpha on downregulation of TM and EPCR. These data demonstrate that TNF-alpha significantly decreases expression of TM and EPCR at both mRNA and protein levels in several human endothelial cells. Curcumin can effectively block TNF-alpha-induced endothelial dysfunction. This study suggests a new molecular mechanism of inflammation-induced thrombosis and a new therapeutic strategy to prevent this clinical problem.

Thrombomodulin: tumour biology and prognostic implications.

BACKGROUND: Thrombomodulin (TM) is an endothelial receptor that exerts anti-coagulant, anti-fibrinolytic, and anti-inflammatory activity by inhibiting thrombin and cellular adhesion. There is growing evidence that TM plays a role in tumour behaviour. METHODS: The electronic literature (1966-2004) was reviewed with a specific focus on tumour biology. RESULTS: TM is expressed on both the endothelium and tumour cells in several cancers. Loss of expression denotes a more malignant profile with poorer prognosis. Loss of TM is mediated by hypoxia, endotoxin, and various cytokines, while up-regulation can be achieved by pharmacological manipulation (e.g. pentoxyfylline and statins). CONCLUSION: Originally described as an endothelial anticoagulant, TM plays a key role in tumour biology and prognostics, and provides a potential therapeutic target in impeding cancer spread.

Hyperhomocyst(e)inemia and endothelial dysfunction in IDDM.

OBJECTIVE: While elevated blood levels of homocyst(e)ine represent an independent risk factor for macrovascular disease, we assessed the link between hyperhomocyst(e)inemia and diabetic microvascular diseases. RESEARCH DESIGN AND METHODS: Plasma levels of homocyst(e)ine and thrombomodulin (TM), markers of endothelial cell damage, were measured before and 3 h after oral methionine loading in 75 patients with IDDM and 40 healthy control subjects matched for sex and age. Exclusion criteria were hyperlipidemia, hypertension, smoking, or positive family history for cardiovascular disease. RESULTS: IDDM patients had higher pre- and postload plasma levels of homocyst(e)ine than did healthy control subjects (12.0 vs. 7.7 mumol/l and 27.6 vs. 16.0 mumol/l; P < 0.001). Of 75 IDDM patients, 26 had plasma homocyst(e)ine levels above the normal range (means +/- 2 SD of values obtained in the control group). These IDDM patients with hyperhomocyst(e)inemia had higher plasma TM levels (62.2 vs. 38.2 ng/ml, P < 0.001), higher albumin excretion rates (485 vs. 115 mg/l, P < 0.005), and a higher prevalence of late diabetic complications (nephropathy, 76 vs. 33%; retinopathy, 69 vs. 51%; neuropathy, 57 vs. 41%; and macroangiopathy, 57 vs. 33%) compared with IDDM patients with normal plasma homocyst(e)ine. In vitro experiments with human umbilical vein cells showed an increased release of TM into the culture supernatant only when endothelial cells were pretreated with advanced glycation end product (AGE)-albumin before L-homocystine was added. A synergistic action of homocyst(e)ine and AGEs might contribute to vascular complications in patients with diabetes. CONCLUSIONS: Hyperhomocyst(e)inemia is common in nephropathic diabetic patients and may contribute to the enhanced morbidity and mortality from cardiovascular diseases characteristically observed in IDDM patients with diabetic nephropathy.

Hyperhomocyst(e)inemia and endothelial dysfunction in IDDM.

OBJECTIVE: Considering that elevated blood levels of homocyst(e)ine represent a known independent risk factor for macrovascular disease, we assessed the link between hyperhomocyst(e)inemia and diabetic microvascular complications. RESEARCH DESIGN AND METHODS: Homocyst(e)ine and thrombomodulin plasma levels, a marker of endothelial cell damage, were measured before and 3 h after oral methionine loading in 75 patients with stable, well-controlled IDDM and 40 healthy control subjects matched for sex and age. Exclusion criteria were hyperlipidemia, hypertension, smoking, or positive family history for cardiovascular disease. RESULTS: IDDM patients had higher pre- and postload homocyst(e)ine plasma levels than did healthy control subjects (12.0 vs. 7.7 mumol/l and 27.6 vs. 16.0 mumol/l; P < 0.001). Of 75 IDDM patients, 26 had homocyst(e)ine plasma levels above the normal range (defined as mean +2 SD of values obtained in the control group). The IDDM patients with hyperhomocyst(e)inemia had higher thrombomodulin plasma levels (62.2 vs. 38.2 ng/ml; P < 0.001), higher albumin excretion rates (485 vs. 115 mg/l; P < 0.005), and a higher prevalence of late diabetic complications (nephropathy, 76 vs. 33%; retinopathy, 69 vs. 51%; neuropathy, 57 vs. 41%; macroangiopathy, 57 vs. 33%) compared with IDDM patients with normal plasma homocyst(e)ine. In vitro experiments with human umbilical vein cells show an increased release of thrombomodulin into the culture supernatant only when endothelial cells were pretreated with advanced glycation end product (AGE)-albumin before L-homocystine was added. A synergistic action of homocyst(e)ine and AGEs might contribute to vascular complications of patients with diabetes. CONCLUSIONS: Hyperhomocyst(e)inemia is common in nephropathic diabetic patients and may contribute to the enhanced morbidity and mortality from cardiovascular diseases characteristically observed in IDDM patients with diabetic nephropathy.

Reduced expression of endothelial cell markers after 1 year treatment with simvastatin and atorvastatin in patients with coronary heart disease.

The study was aimed at investigating the effects, after treatment for 1 year, of two different statins on the levels of circulating biochemical markers of endothelial function in patients with established coronary heart disease, with the hypothesis that statins might reduce these levels. Twenty-eight patients were randomized to treatment with atorvastatin and 30 to simvastatin for 1 year. The starting dose in both groups was 20 mg/day. Soluble forms of P-selectin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were determined to assess inflammatory activity of the endothelium, and tissue plasminogen activator antigen (tPAag), von Willebrand factor and thrombomodulin for evaluation of the haemostatic function. In the total study population there were significantly reduced levels after 1 year treatment in ICAM-1 (P<0.001), E-selectin (P=0.022) and P-selectin (P<0.001), whereas a significant increase was observed in VCAM-1 (P=0.003). Almost the same pattern was seen within both groups although the increase in VCAM-1 was only seen in the simvastatin group (P=0.017). An overall reduction in tPAag was further observed (P=0.048). The reduction in proinflammatory and to some extent haemostatic markers of endothelial function after 1 year treatment with either simvastatin or atorvastatin may be indicative of a less activated state of the endothelium which possibly may contribute to modulation of the progression of atherosclerosis.

Third-generation thrombolytic drugs.

Several third-generation thrombolytic agents have been developed. They are either conjugates of plasminogen activators with monoclonal antibodies against fibrin, platelets, or thrombomodulin; mutants, variants, and hybrids of alteplase and prourokinase (amediplase); or new molecules of animal (vampire bat) or bacterial (Staphylococcus aureus) origin. These variations may lengthen the drug's half-life, increase resistance to plasma protease inhibitors, or cause more selective binding to fibrin. Compared with the second-generation agent (alteplase), third-generation thrombolytic agents such as monteplase, tenecteplase, reteplase, lanoteplase, pamiteplase, and staphylokinase result in a greater angiographic patency rate in patients with acute myocardial infarction, although, thus far, mortality rates have been similar for those few drugs that have been studied in large-scale trials. Bleeding risk, however, may be greater.

Diabetic muscle infarction: a new perspective on pathogenesis and management.

Two patients with insulin dependent diabetes mellitus developed recurrent episodes of focal muscle pain and swelling. Clinical evaluation, magnetic resonance imaging (MRI) and muscle biopsy confirmed the diagnosis of recurrent hemorrhagic muscle infarctions. Our studies suggest that muscle infarction occurred because of hypercoagulability and associated vascular endothelial damage. Based on these findings we recommend long-term anticoagulation to prevent recurrent infarction.

15 deoxy delta12,14 PGJ2 induces procoagulant activity in cultured human endothelial cells.

15 deoxy delta12,14 PGJ2 (15d-PGJ2), a high affinity ligand of peroxisome proliferator-activated receptor gamma (PPARgamma) has been proposed to act as a negative feedback regulator of the inflammatory response. We investigated the effect of 15d-PGJ2 on the anticoagulant property of endothelial cells. 15d-PGJ2 stimulated a moderate but sustained increase in tissue factor (TF) activity in HUVECs and EA.hy926 cells while causing a partial loss of thrombomodulin (TM) activity. When cells were co-treated with 15d-PGJ2 and TNF-alpha, the subsequent elevation of TF activity was synergistically increased over that of cells treated with TNF-alpha alone and the decline of TF activity after 24 h was less marked than TNF-alpha alone. The induction of TF by 15d-PGJ2 alone and in combination with TNF-alpha was reduced in the presence of PD 98059, suggesting the participation of the MEK/ERK pathway. The thiazolidinedione PPARgamma agonist ciglitazone had no effect on TF levels but reduced the expression of endothelial protein C receptor. The ability of 15d-PGJ2 to enhance a procoagulant phenotype arising from TNF-alpha suggests a pro-inflammatory role for the prostaglandin.