Reduction in 99mTc-DPD myocardial uptake with therapy of ATTR cardiomyopathy.

Aims: Novel ribonucleic acid interference (RNAi) therapeutics such as patisiran and inotersen have been shown to benefit neurologic disease course and quality of life in patients with hereditary transthyretin amyloidosis (ATTRv). We aimed to determine the impact of RNAi therapeutics on myocardial amyloid load using quantitative single photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with ATTRv-related cardiomyopathy (ATTRv-CM). We furthermore compared them with wild-type ATTR-CM (ATTRwt-CM) patients treated with tafamidis.Methods and results: ATTRv-CM patients underwent [99mTc]-radiolabeled diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy and quantitative SPECT/CT imaging before and after 12 months (IQR: 11.0-12.0) of treatment with RNAi therapeutics (patisiran: n = 5, inotersen: n = 4). RNAi treatment significantly reduced quantitative myocardial uptake as measured by standardised uptake value (SUV) retention index (baseline: 5.09 g/mL vs. follow-up: 3.19 g/mL, p = .028) in ATTRv-CM patients without significant improvement in cardiac function. Tafamidis treatment resulted in a significant reduction in SUV retention index (4.96 g/mL vs. 3.27 g/mL, p < .001) in ATTRwt-CM patients (historical control cohort: n = 40) at follow-up [9.0 months (IQR: 7.0-10.0)] without beneficial impact on cardiac function.Conclusions: RNAi therapeutics significantly reduce quantitative myocardial uptake in ATTRv-CM patients, comparable to tafamidis treatment in ATTRwt-CM patients, without impact on cardiac function. Serial 99mTc-DPD SPECT/CT imaging may be a valuable tool to quantify and monitor response to disease-specific therapies in both ATTRv-CM and ATTRwt-CM.

Sacubitril/valsartan is well tolerated in patients with longstanding heart failure and history of cancer and improves ventricular function: real-world data.

BACKGROUND: Sacubitril/valsartan has been shown to significantly reduce cardiovascular mortality and hospitalizations due to heart failure in patients with reduced ejection fraction (HFrEF) when compared to enalapril. Data about sacubitril/valsartan in patients with a history of cancer are scarce, as these patients were excluded from the pivotal trial, PARADIGM-HF. The aim of the current study was to assess tolerability of sacubitril/valsartan in patients with a history of cancer. METHODS: We identified 225 patients at our heart failure out-patient unit who fulfilled the indication criteria to receive sacubitril/valsartan. Out of these, 9.3% (n = 21) had a history of histologically confirmed cancer. Oncologic surgery was performed in 16 (76.2%) patients, 11 (52.4%) patients received previous antineoplastic therapy and 9 patients (42.9%) radiation. RESULTS: Sacubitril/valsartan was withdrawn in 3 of 21 patients (14.3%) because of dizziness (n = 2) or pruritus (n = 1). After a median follow-up of 12 months (range 1-34 months), NYHA functional class improved significantly from NYHA 3 to NYHA 2 (mean -0.6, p = 0.006) and left ventricular ejection fraction as assessed by echocardiography increased significantly from 26.8 ± 5.4% to 39.2 ± 10% (mean + 12%, CI 95% [8.4-16.4], p = 0.0004). NT-proBNP was significantly reduced (baseline median 2774 pg/ml, range 1441 - 12,982 vs follow-up 1266 pg/ml, range 199-6324, p = 0.009). There was no significant change in creatinine levels (1.18 ± 0.4 vs 1.22 ± 0.4 mg/dl; mean + 0.005 mg/dl, CI 95% [-0.21- 0.12], p = 0.566). CONCLUSIONS: In our pilot study we show that sacubitril/valsartan is generally well tolerated in patients with HFrEF and history of cancer. Importantly, even patients with long-standing cardiotoxicity induced heart failure can be treated and up-titrated with sacubitril/valsartan to usual target dosages, leading to improvement in LV function and biomarkers. Larger studies are needed to confirm these findings in cancer patients with cardiotoxicity.

Principal Morphomic and Functional Components of Secondary Mitral Regurgitation.

OBJECTIVES: The aim of this work was to identify the key morphological and functional features in secondary mitral regurgitation (sMR) and their prognostic impact on outcome. BACKGROUND: Secondary sMR in patients with heart failure and reduced ejection fraction typically results from distortion of the underlying cardiac architecture. The morphological components which may account for the clinical impact of sMR have not been systematically assessed or correlated with clinical outcomes. METHODS: Morphomic and functional network profiling were performed on a cohort of patients with stable heart failure optimized on guideline-based medical therapy. Principal component (PC) analysis and subsequent cluster analysis were used to condense the morphomic and functional data first into PCs with varimax rotation (PCVmax) and second into homogeneous clusters. Clusters and PCs were tested for their correlations with clinical outcomes. RESULTS: Morphomic and functional data from 383 patients were profiled and subsequently condensed into PCs. PCVmax 1 describes high loadings of left atrial morphological information, and PCVmax 2 describes high loadings of left ventricular (LV) topology. Based on these components, 4 homogeneous clusters were derived. sMR was most prominent in clusters 3 and 4, with the morphological difference being left ventricular size (median end-diastolic volume 188 mL [interquartile range: 160 mL-224 mL] vs 315 mL [264 mL-408 mL]; P < 0.001). Clusters were associated with mortality (P < 0.001), but sMR remained independently associated with mortality after adjusting for the clusters (adjusted HR: 1.42; 95% CI: 1.14-1.77; P < 0.01). The detrimental association of sMR with mortality was mainly driven by cluster 3 (HR: 2.18; 95% CI: 1.32-3.60; P = 0.002), the "small LV cavity" phenotype. CONCLUSIONS: These results challenge the current perceptions that sMR in heart failure with reduced ejection fraction results exclusively from global or local LV remodeling and are suggestive of a potential role of the left atrial component. The association of sMR with mortality cannot be purely attributed to cardiac morphology alone, supporting other complementary key aspects of mitral valve closure consistent with the force balance theory. Unsupervised clustering supports the association of sMR with mortality predominantly driven by the small LV cavity phenotype, as previously suggested by a conceptional framework and termed disproportionate sMR.

Toll-like receptor 2 and 9 expression on circulating neutrophils is associated with increased mortality in critically ill patients.

BACKGROUND: Toll-like receptors (TLRs) play an important role in inflammatory processes in critically ill patients by binding to pathogen-associated molecular patterns and danger-associated molecular patterns (DAMPs). Whether neutrophil or monocyte TLR expression patterns are associated with outcome in critical illness is unknown. OBJECTIVES: To answer this question, we conducted a prospective, observational study including 215 consecutive patients admitted to a medical ICU at a tertiary care center. METHODS: Blood was drawn at admission and expression of TLR-2, TLR-4, and TLR-9 on neutrophils and monocytes were analyzed by flow cytometry. RESULTS: Median Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 19, and 30-day mortality was 26%. TLR-2 expression on neutrophils was associated with APACHE II, Simplified Acute Physiology Score II, and Sepsis-related Organ Failure Assessment score. TLR-2 (P < 0.001) and TLR-9 (P < 0.05) expression on neutrophils was significantly higher in nonsurvivors. In contrast, neutrophil TLR-4 expression and monocyte TLR expression were not associated with survival. Neutrophil TLR-2 (odds ratio 3.8; 95% confidence interval 1.4-10.2; P < 0.05) and TLR-9 (odds ratio 4.0; 95% confidence interval 2.0-8.1; P < 0.001) expression in the third tertile predicted mortality independent from APACHE II, serum lactate, serum creatinine, and procalcitonin, respectively. CONCLUSION: We provide evidence for prognostic properties of neutrophil TLR-2 and TLR-9 expression regarding 30-day mortality in unselected critically ill patients, independent from baseline clinical characteristics, and laboratory values. These findings suggest that specific TLR-dependent activation of the innate immune system via neutrophils possibly caused by cell damage and release of otherwise intracellular components may play a significant role in the pathophysiology of critical illness.

Levosimendan exerts anti-inflammatory effects on cardiac myocytes and endothelial cells in vitro.

Levosimendan is a positive inotropic drug for the treatment of acute decompensated heart failure (HF). Clinical trials showed that levosimendan was particularly effective in HF due to myocardial infarction. Myocardial necrosis induces a strong inflammatory response, involving chemoattractants guiding polymorphonuclear neutrophils (PMN) into the infarcted myocardial tissue. Our aim was to examine whether levosimendan exhibits anti-inflammatory effects on human adult cardiac myocytes (HACM) and human heart microvascular endothelial cells (HHMEC). Cardiac myocytes and endothelial cells were stimulated with interleukin-1ß (IL)-1ß (200 U/ml) and treated with levosimendan (0.1-10 µM) for 2-48 hours. IL-1ß strongly induced expression of IL-6 and IL-8 in HACM and E-selectin and intercellular adhesion molecule-1 (ICAM-1) in HHMEC and human umbilical vein endothelial cells (HUVEC). Treatment with levosimendan strongly attenuated IL-1ß-induced expression of IL-6 and IL-8 in HACM as well as E-selectin and ICAM-1 in ECs. Levosimendan treatment further reduced adhesion of PMN to activated endothelial cells under both static and flow conditions by approximately 50 %. Incubation with 5-hydroxydecanoic acid, a selective blocker of mitochondrial ATP-dependent potassium channels, partly abolished the above seen anti-inflammatory effects. Additionally, levosimendan strongly diminished IL-1ß-induced reactive oxygen species and nuclear factor-κB (NF-κB) activity through inhibition of S536 phosphorylation. In conclusion, levosimendan exhibits anti-inflammatory effects on cardiac myocytes and endothelial cells in vitro. These findings could explain, at least in part, the beneficial effects of levosimendan after myocardial infarction.

Small high-density lipoprotein is associated with monocyte subsets in stable coronary artery disease.

OBJECTIVE: High-density lipoprotein (HDL) particles are heterogeneous in structure and function and the role of HDL subfractions in atherogenesis is not well understood. It has been suggested that small HDL may be dysfunctional in patients with coronary artery disease (CAD). Monocytes are considered to play a key role in atherosclerotic diseases. Circulating monocytes can be divided into three subtypes according to their surface expression of CD14 and CD16. Our aim was to examine whether monocyte subsets are associated with HDL subfractions in patients with atherosclerosis. METHODS: We included 90 patients with angiographically stable CAD. Monocyte subsets were defined as classical monocytes (CD14++CD16-; CM), intermediate monocytes (CD14++CD16+; IM) and non-classical monocytes (CD14+CD16++; NCM). HDL subfractions were measured by electrophoresis on polyacrylamide gel. RESULTS: Serum levels of small HDL correlated with circulating pro-inflammatory NCM and showed an inverse relationship to circulating CM independently from other lipid parameters, risk factors, inflammatory parameters or statin treatment regime, respectively. IM were not associated with small HDL. In particular, patients with small HDL levels in the highest tertile showed dramatically increased levels of NCM (14.7 ± 7% vs. 10.7 ± 5% and 10.8 ± 5%; p = 0.006) and a decreased proportion of CM (79.3 ± 7% vs. 83.7 ± 6% and 83.9 ± 6%; p = 0.004) compared to patients in the two lower tertiles. In contrast, intermediate HDL, large HDL and total HDL were not associated with monocyte subset distribution. CONCLUSION: Small HDL levels are associated with pro-inflammatory NCM and inversely correlated with CM. This may suggest that small HDL could have dysfunctional anti-inflammatory properties in patients with established CAD.

An increase of VEGF plasma levels is associated with restenosis of drug-eluting stents.

AIMS: Drug-eluting stents (DES) reduce late lumen loss compared to bare metal stents but were not able to eradicate in-stent restenosis (ISR) fully. Vascular endothelial growth factor (VEGF) may inhibit late lumen loss through accelerated reendothelialisation, but may also promote neointima formation by proinflammatory effects. The aim of this study was to evaluate whether endogenous plasma levels of VEGF are associated with development of ISR after implantation of DES. METHODS AND RESULTS: We studied 85 patients who were treated with 159 DES. VEGF plasma levels were determined before and 24 hours after PCI. During the eight-month follow-up period, two patients (2.4%) died of cardiovascular causes and 12 patients (14.5% of patients, 7.6% of stents) developed angiographic ISR. Basal VEGF plasma levels were not different in patients with and without ISR at follow-up. In contrast to patients without ISR, VEGF increased significantly upon PCI in patients with ISR (p<0.005). Patients with a decrease of VEGF after PCI had a restenosis rate of 2.4% compared to a restenosis rate of 26.2% in patients with an increase of VEGF after the procedure (p<0.05). This was independent from clinical and angiographic risk factors. CONCLUSIONS: Basal plasma levels of VEGF are not associated with the development of ISR. However, an increase of VEGF after PCI is associated with a dramatically increased ISR rate after implantation of DES.

Premature myocardial infarction is associated with low serum levels of Wnt-1.

OBJECTIVE: Besides its effects on glucose and lipid metabolism, the Wnt pathway has been increasingly implicated in the regulation of proliferation, migration and survival of vascular cells. In addition, defective Wnt signaling has been identified in a family with autosomal dominant early coronary artery disease. The aim of this study was to investigate whether premature coronary artery disease is associated with features of decreased Wnt signaling. METHODS AND RESULTS: We prospectively enrolled 100 consecutive young survivors of myocardial infarction (MI≤40 years of age) from two high-volume cardiac catheterization centers and 100 sex and age matched hospital controls. We determined serum levels of Wnt-1 and its antagonist Dkk-1 by ELISA. MI patients showed significantly lower Wnt-1 levels as compared to controls (151 ng/mL, IQR 38-473 ng/mL vs. 233 ng/mL, IQR 62-1756; p<0.005) whereas Dkk-1 was not different at baseline. Wnt-1 levels remained stable over time, whereas Dkk-1 significantly increased at one-year follow-up from 3557, IQR 2306-5810 pg/mL to 4973, IQR 3293-7093 pg/mL (p<0.001). In the stable phase of the disease, Wnt-1 levels were lower (p<0.005) and Dkk-1 levels were significantly higher (p<0.001) as compared to controls. Wnt-1 at follow-up was associated with glucose, HbA1c, non-HDL-, HDL-cholesterol and triglyceride levels but no other features of the metabolic syndrome. CONCLUSION: This study establishes an association between low Wnt-1 and high Dkk-1 serum levels and premature myocardial infarction. Wnt-1 is associated with markers of glucose and lipid metabolism. Further research elucidating the role of Wnt pathways in premature coronary artery disease and metabolic syndrome is warranted.

The complement component C5a is present in human coronary lesions in vivo and induces the expression of MMP-1 and MMP-9 in human macrophages in vitro.

The complement component C5a is formed during activation of the complement cascade and exerts chemotactic and proinflammatory effects. Macrophages, which are localized in the rupture-prone shoulder regions of coronary plaques, are thought to play a major role in plaque destabilization and rupture through the production of matrix metalloproteinases (MMPs). When human monocyte-derived macrophages were stimulated in vitro with C5a, MMP-1 and MMP-9 mRNA levels were significantly increased. Furthermore, C5a up-regulated MMP-1 and MMP-9 antigens and activity, as determined by ELISA and specific activity assays. These effects were blocked by antibodies against the receptor C5aR/CD88. In addition, blocking experiments revealed that MMP-1 expression was mediated by activation of the transcription factor AP-1, and MMP-9 expression was induced by activation of NF-κB and AP-1. Immunohistochemical analysis of human coronary plaques demonstrated the colocalization of C5a, MMP-1, and MMP-9 in vivo. Together, these observations indicate that activation of the complement cascade and formation of C5a may play a role in the onset of acute coronary events by induction of MMPs in atherosclerotic lesions.

Oncostatin M-enhanced vascular endothelial growth factor expression in human vascular smooth muscle cells involves PI3K-, p38 MAPK-, Erk1/2- and STAT1/STAT3-dependent pathways and is attenuated by interferon-γ.

The pleiotropic cytokine oncostatin M (OSM), a member of the glycoprotein (gp)130 ligand family, plays a key role in inflammation and cardiovascular disease. As inflammation precedes and accompanies pathological angiogenesis, we investigated the effect of OSM and other gp130 ligands on vascular endothelial growth factor (VEGF) production in human vascular smooth muscle cells (SMC). Human coronary artery SMC (HCASMC) and human aortic SMC (HASMC) were treated with different gp130 ligands. VEGF protein was determined by ELISA. Specific mRNA was detected by RT-PCR. Western blotting was performed for signal transducers and activators of transcription1 (STAT1), STAT3, Akt and p38 mitogen-activated protein kinase (p38 MAPK). OSM mRNA and VEGF mRNA expression was analyzed in human carotid endaterectomy specimens from 15 patients. OSM increased VEGF production in both HCASMC and HASMC derived from different donors. OSM upregulated VEGF and OSM receptor-specific mRNA in these cells. STAT3 inhibitor WP1066, p38 MAPK inhibitors SB-202190 and BIRB 0796, extracellular signal-regulated kinase1/2 (Erk1/2) inhibitor U0126, and phosphatidylinositol 3-kinase (PI3K) inhibitors LY-294002 and PI-103 reduced OSM-induced VEGF synthesis. We found OSM expression in human atherosclerotic lesions where OSM mRNA correlated with VEGF mRNA expression. Interferon-γ (IFN-γ), but not IL-4 or IL-10, reduced OSM-induced VEGF production in vascular SMC. Our findings that OSM, which is present in human atherosclerotic lesions and correlates with VEGF expression, stimulates production of VEGF by human coronary artery and aortic SMC indicate that OSM could contribute to plaque angiogenesis and destabilization. IFN-γ reduced OSM-induced VEGF production by vascular SMC.

Thrombin induces the expression of oncostatin M via AP-1 activation in human macrophages: a link between coagulation and inflammation.

Macrophages as inflammatory cells are involved in the pathogenesis of atherosclerosis that today is recognized as an inflammatory disease. Activation of coagulation leads to the late complication of atherosclerosis, namely atherothrombosis with its clinical manifestations stroke, unstable angina, myocardial infarction, and sudden cardiac death. Thus inflammation and coagulation play fundamental roles in the pathogenesis of atherosclerosis. We show that the coagulation enzyme thrombin up-regulates oncostatin M (OSM), a pleiotropic cytokine implicated in the pathophysiology of vascular disease, in human monocyte-derived macrophages (MDMs) up to 16.8-fold. A similar effect was seen in human peripheral blood monocytes and human plaque macrophages. In MDMs, the effect of thrombin on OSM was abolished by PPACK and mimicked by a PAR-1-specific peptide. Thrombin induced phosphorylation of ERK1/2 and p38 in MDMs. The ERK1/2 inhibitor PD98059 blocked the effect of thrombin on OSM production in MDMs, whereas the p38 inhibitor SB202190 had no effect. Thrombin induced translocation of c-fos and c-jun to the nucleus of MDMs. Using OSM promoter-luciferase reporter constructs transfected into MDMs, we show that a functional AP-1 site is required for promoter activation by thrombin. We present another link between coagulation and inflammation, which could impact on the pathogenesis of atherosclerosis.

Clopidogrel pretreatment abolishes increase of PAI-1 after coronary stent implantation.

BACKGROUND: Plasminogen activator inhibitor-1 (PAI-1) has been shown to increase after percutaneous coronary intervention (PCI). Whether activated platelets, local trauma with activation of resident vascular cells or the acute phase response is the source of this PAI-1 increase is not well defined. Therefore we examined whether intensive platelet inhibition may modulate PAI-1 levels or whether the PAI-1 increase is associated with the acute phase protein C-reactive protein (CRP). METHODS: We included 51 patients with stable angina who underwent elective PCI with stent implantation. At the time of study, routine pretreatment with clopidogrel before PCI was not standard of care, but left to the discretion of the referring cardiologist. We matched 17 patients with stable angina that were not pretreated with clopidogrel but received a loading dose of 300 mg immediately after stent implantation according age, sex and smoking with 34 patients that received clopidogrel at least 12 to 24 hours before PCI. Blood samples for measurement of PAI-1, t-PA and CRP were taken directly before and 24 hours after the procedure. RESULTS: PAI-1 and t-PA active antigen plasma levels before PCI were not different in patients with and without clopidogrel pretreatment. Whereas PCI induced a significant increase of PAI-1 levels in patients without pretreatment (p<0.05), the procedure had no effect on PAI-1 active antigen in patients pretreated with clopidogrel. This resulted in significant lower PAI-1 plasma levels 24 hours after PCI in patients with pretreatment (p<0.05). CRP was not associated with pre- or postprocedural PAI-1 levels. CONCLUSION: Clopidogrel pretreatment completely abolishes the increase of PAI-1 active antigen after coronary stent implantation. This suggests that peri-procedural platelet activation might play a major role for the increase of PAI-1 after PCI thus increasing the risk of acute and subacute thrombus formation based on a reduced endogenous fibrinolytic system.

In human macrophages the complement component C5a induces the expression of oncostatin M via AP-1 activation.

OBJECTIVE: Macrophages produce the cytokine oncostatin M (OSM), which beside other functions is also involved in inflammation. The complement component C5a mobilizes and activates these cells at inflammatory sites. We examined the effect of C5a on OSM production in human monocytes and in human monocyte-derived macrophages. METHODS AND RESULTS: For macrophage transformation peripheral blood monocytes were cultivated for 8 to 10 days in the presence of human serum. C5a significantly increased in these cells OSM antigen as determined by specific ELISA and mRNA as quantitated by real-time polymerase chain reaction in these cells as well as in plaque macrophages. This effect was blocked by antibodies against the receptor C5aR/CD88 and by pertussis toxin. The C5a-induced phosphorylation of p38 and JNK and the C5a-induced increase in OSM production in macrophages was abolished by 2 p38 inhibitors and by a JNK inhibitor. Furthermore C5a increased the nuclear translocation of c-fos and c-jun. Using different OSM promoter deletion mutant constructs we show that the putative AP-1 element is responsible for activation of OSM promoter activity by C5a. CONCLUSIONS: Our data establish a link between the complement system and the gp130 receptor cytokine family with possible implications for the pathology of inflammatory diseases.

The estrogen metabolite 17beta-dihydroequilenin counteracts interleukin-1alpha induced expression of inflammatory mediators in human endothelial cells in vitro via NF-kappaB pathway.

In most studies showing cardio- and vasculoprotective effects of estrogens, 17beta-estradiol was used and little information on possible effects of different estrogen metabolites is yet available. We investigated whether particular estrogen metabolites are effective in counteracting inflammatory activation of human endothelium. Human endothelial cells were incubated with 17alpha-dihydroequilenin, 17beta-dihydroequilenin, delta-8,9-dehydroestrone, estrone and 17beta-estradiol and stimulated with interleukin (IL)-1alpha. The expression of IL-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1) was determined. 17beta-dihydroequilenin and 17beta-estradiol at a concentration of 1 microM reduced IL-1alpha-induced up regulation of IL-6, IL-8 and MCP-1 close to control levels. When both compounds were used in combination an additive effect was observed. 17alpha-dihydroequilenin and delta-8,9-dehydroestrone showed a similar anti-inflammatory effect only when used at 10 microM whereas estrone had no effect. The effect of 17beta-dihydroequilenin on IL-1alpha-induced production of IL-6, IL-8 and MCP-1 was reversed by the estrogen receptor antagonist ICI 182,780. 17beta-dihydroequilenin also inhibited IL-1alpha-induced translocation of p50 and p65 to the nucleus of the cells. We have identified the estrogen metabolite 17beta-dihydroequilenin, as an inhibitor of inflammatory activation of human endothelial cells. Characterization of specific estrogens--as shown in our study--could provide the basis for tailored therapies, which might be able to achieve vasoprotection without adverse side effects.

Prostaglandin E1 induces vascular endothelial growth factor-1 in human adult cardiac myocytes but not in human adult cardiac fibroblasts via a cAMP-dependent mechanism.

Prostaglandin E(1) (PGE(1)) has been used to treat pulmonary hypertension and peripheral artery occlusive disease and has been successfully employed for pharmacological bridging to transplantation in patients with chronic end-stage heart failure. In addition to its vasoactive effects PGE(1) was shown to stimulate angiogenesis in animal models. Recently we showed that PGE(1)-induced angiogenesis in hearts of patients with ischemic heart disease. We proposed that the angiogenic action of PGE(1) is mediated by vascular endothelial growth factor (VEGF). In the present paper we studied a possible effect of PGE(1) on the expression of VEGF-1 in cultured human adult cardiac myocytes (HACM) and cultured human adult cardiac fibroblasts (HACFB), respectively, to identify a cellular source of VEGF-1 in patients treated with PGE(1). We also aimed to delineate mechanisms involved in a possible regulation of VEGF-1 by PGE(1) in these cells. When HACM, isolated from human myocardial tissue, were treated with PGE(1), a significant up to 3-fold increase in VEGF-1 production could be observed. These results could be confirmed on the level of specific mRNA expression as determined by real-time polymerase chain reaction. The effect of PGE(1) on VEGF-1 expression could be blocked by H089, an inhibitor of cAMP-dependent protein kinase A. In HACFB, also isolated from human myocardial tissue, no effect of PGE(1) on VEGF-1 production was seen. If this effect of PGE(1) is also operative in the in vivo situation, one could speculate that cardiac myocytes could be a cellular source of PGE(1)-induced VEGF-1 expression in patients treated with this drug.

Catecholamines potentiate LPS-induced expression of MMP-1 and MMP-9 in human monocytes and in the human monocytic cell line U937: possible implications for peri-operative plaque instability.

Plaque destabilization leading to myocardial infarction is observed after surgery even if the intervention is of noncardiovascular nature. Mediators of peri- or postoperative stress responsible for such events could include catecholamines and lipopolysaccharide (LPS). Monocytes may be involved in destabilization of atherosclerotic plaques by production of matrix metalloproteinases (MMP). We examined whether catecholamines could affect the expression of MMPs in human monocytes/macrophages and whether catecholamines could modulate LPS-stimulated expression of particular MMPs in these cells. Epinephrine and norepinephrine up-regulated MMP-1 and potentiated LPS-induced expression of MMP-1 in peripheral blood monocytes and monocyte-derived macrophages. We further characterized this effect employing the monocytic cell line U937 and showed that catecholamines potentiate LPS-induced effects on MMP-1 and MMP-9 antigen and activity. mRNA levels of the respective MMPs also increased. These effects did not result from higher mRNA stability but rather from increased transcription possibly induced by enhanced DNA binding of AP-1 and were mediated by either beta1- or beta 2-receptors. If this mechanism is also effective in vivo, our findings might, at least in part, help to explain the observation that cardiac events are important causes of morbidity and mortality after noncardiac surgery and support the findings that peri-operative beta-blockade has been shown to reduce postoperative mortality from cardiac events.