Methotrexate and MX-68, a New Derivative of Methotrexate, Limit Infarct Size via Adenosine-Dependent Mechanisms in Canine Hearts

Macrophage heterogeneity in myocardial infarction: Evolution and implications for diverse therapeutic approaches

Given the extensive participation of myeloid cells (especially monocytes and macrophages) in both inflammation and resolution phases post-myocardial infarction (MI) owing to their biphasic role, these cells are considered as crucial players in the disease pathogenesis. Multiple studies have agreed on the significant contribution of macrophage polarization theory (M2 vs. M1) while determining the underlying reasons behind the observed biphasic effects; nevertheless, this simplistic classification attracts severe drawbacks. The advent of multiple advanced technologies based on OMICS platforms facilitated a successful path to explore comprehensive cellular signatures that could expedite our understanding of macrophage heterogeneity and plasticity. While providing an overall basis behind the MI disease pathogenesis, this review delves into the literature to discuss the current knowledge on multiple macrophage clusters, including the future directions in this research arena. In the end, our focus will be on outlining the possible therapeutic implications based on the emerging observations.

Huangqi Guizhi Wuwu Decoction Improves Arthritis and Pathological Damage of Heart and Lung in TNF-Tg Mice

Background: Huangqi Guizhi Wuwu Decoction (HGWD) is a traditional and effective Chinese medicine compound decoction for the treatment of rheumatoid arthritis (RA). However, there is few research on the treatment of rheumatoid cardiopulmonary complications. The present study was to study whether HGWD can alleviate the pathological changes caused by rheumatoid arthritis and cardiopulmonary complications.

Methods: Five 3-month-old TNF-Tg mice were treated with HGWD (9.1 g/kg) once a day or the same dose of normal saline lasted for 8 weeks, and wild-type littermates of the same age were used as a negative control, and methotrexate (MTX) was intraperitoneally administered as a positive control. After the treatment, pathological staining was performed on the mouse ankle joints, heart, and lungs.

Result: It was found that HGWD reduced the inflammation of the ankle joint synovium in TNF-Tg mice, and reduced myocardial hypertrophy, inflammatory infiltration and fibrosis of heart, as well as lung inflammation and fibrosis. Immunohistochemical staining with anti-TNF-α antibody showed that HGWD reduced the expression of TNF-α in the heart of TNF-Tg mice.

Conclusion: In conclusion, HGWD alleviates joint inflammation in TNF-Tg mice and reduces the pathological changes of the heart and lungs.

Methotrexate Therapy Promotes Cell Coverage and Stability in in-Stent Neointima

PURPOSE

Anti-proliferative drugs released from drug-eluting stents delay cell coverage and vascular healing, which increases the risk of late stent thrombosis. We assessed the potential effects of systemic methotrexate (MTX) on cell coverage, vascular healing and inflammation activation in vivo and in vitro.

METHODS

We applied MTX in the right common carotid artery in a rabbit stenting model to determine the impact on cell coverage and inflammation activation using a serial optical coherence tomography (OCT) analysis and elucidated the molecular mechanism of MTX in human umbilical vein endothelial cells (HUVECs).

RESULTS

Low-dose MTX promoted the development of cell coverage and vascular healing, which was associated with fewer uncovered struts (%) and cross-sections with any uncovered struts (%) at 4 weeks of stenting. The MTX group also exhibited lower rates of heterogeneity, microvessels and per-strut low-signal-intensity layers, indicating neointimal instability at 12 weeks of stenting. In vitro, low-dose MTX strongly inhibited HUVEC apoptosis, promoted proliferation and inhibited inflammatory activation by targeting the phosphoinositide 3-kinase (PI3K)/AKT signalling pathway.

CONCLUSION

Low-dose MTX may be a key means of promoting early cell coverage via the inhibition of the inflammatory response and stability of neointima by targeting inflammatory pathways after stent implantation.

MTX Treatment Does Not Improve Outcome in Mice with AMI

BACKGROUND

Targeting inflammation in patients with coronary artery disease and/or acute myocardial infarction (AMI) is a matter of debate. Methotrexate (MTX) is one of the most widely used immunosuppressants. Cardiovascular Inflammation Reduction Trial (CIRT) recently failed to demonstrate reduced cardiovascular events in MTX-treated patients. However, it is not known if long-term MTX treatment improves cardiac outcome in AMI. Therefore, in this study, we investigated the postischemic phase in MTX-treated mice undergoing AMI.

METHODS

Wild-type mice received MTX medication intraperitoneally for 2 weeks. Afterward, AMI was induced by transient left anterior ascending artery ligation. Postischemic cardiac damage after 24 h was assessed.

RESULTS

MTX treatment did not affect infarct size as compared to control (IS/AAR: Con 76.20% ± 12.37%/AAR vs. MTX 73.51 ± 11.72%/AAR, p = 0.64). Moreover, systolic function and structural parameters did not differ between groups (24hejection fraction: Con 36.49 ± 3.23% vs. MTX 32.77 ± 2.29%, p = 0.41; 24hLVID; d: Con 3.57 ± 0.17 mm vs. MTX 3.19 ± 0.13 mm, p = 0.14). Platelets were increased by MTX (Con 1,442 ± 69.20 × 103/mm3 vs. MTX 1,920 ± 68.68 × 103/mm3, p < 0.0001). White blood cell and RBC as well as rate of monocytes, granulocytes, lymphocytes, and serum amyloid P levels were equal.

CONCLUSION

MTX medication did not improve postischemic cardiac damage in a murine model of AMI. Future trials are needed to identify and investigate other anti-inflammatory targets to improve cardiovascular outcome.

Ultrasound-assisted synthesis of highly functionalized benzo[1,3]thiazine via Cu-catalyzed intramolecular CH activation reaction from isocyanides, aniline-benzoyl(acetyl) isothiocyanate adduct

A facile sonochemical route for the synthesis of benzo[1,3]thiazine derivatives via a one pot, multicomponent, intramolecular CH activation reaction from isocyanides, aniline and benzoyl (acetyl) isothiocyanate adduct catalyzed by copper (I) iodide in acetone at 30 °C have been reported. The advantages of the described method include using simple and readily available starting materials and performing under mild copper-catalytic reaction conditions and also obtaining pure product with high yield without applying column chromatography. Furthermore, using the sonochemical methodology as an efficient method led to reduce the reaction times.

Anti-inflammatory therapies in myocardial infarction: failures, hopes and challenges

In the infarcted heart, the damage-associated molecular pattern proteins released by necrotic cells trigger both myocardial and systemic inflammatory responses. Induction of chemokines and cytokines and up-regulation of endothelial adhesion molecules mediate leukocyte recruitment in the infarcted myocardium. Inflammatory cells clear the infarct of dead cells and matrix debris and activate repair by myofibroblasts and vascular cells, but may also contribute to adverse fibrotic remodelling of viable segments, accentuate cardiomyocyte apoptosis and exert arrhythmogenic actions. Excessive, prolonged and dysregulated inflammation has been implicated in the pathogenesis of complications and may be involved in the development of heart failure following infarction. Studies in animal models of myocardial infarction (MI) have suggested the effectiveness of pharmacological interventions targeting the inflammatory response. This article provides a brief overview of the cell biology of the post-infarction inflammatory response and discusses the use of pharmacological interventions targeting inflammation following infarction. Therapy with broad anti-inflammatory and immunomodulatory agents may also inhibit important repair pathways, thus exerting detrimental actions in patients with MI. Extensive experimental evidence suggests that targeting specific inflammatory signals, such as the complement cascade, chemokines, cytokines, proteases, selectins and leukocyte integrins, may hold promise. However, clinical translation has proved challenging. Targeting IL-1 may benefit patients with exaggerated post-MI inflammatory responses following infarction, not only by attenuating adverse remodelling but also by stabilizing the atherosclerotic plaque and by inhibiting arrhythmia generation. Identification of the therapeutic window for specific interventions and pathophysiological stratification of MI patients using inflammatory biomarkers and imaging strategies are critical for optimal therapeutic design.

Methotrexate carried in lipid core nanoparticles reduces myocardial infarction size and improves cardiac function in rats

Purpose

Acute myocardial infarction (MI) is accompanied by myocardial inflammation, fibrosis, and ventricular remodeling that, when excessive or not properly regulated, may lead to heart failure. Previously, lipid core nanoparticles (LDE) used as carriers of the anti-inflammatory drug methotrexate (MTX) produced an 80-fold increase in the cell uptake of MTX. LDE-MTX treatment reduced vessel inflammation and atheromatous lesions induced in rabbits by cholesterol feeding. The aim of the study was to investigate the effects of LDE-MTX on rats with MI, compared with commercial MTX treatment.

Materials and methods

Thirty-eight Wistar rats underwent left coronary artery ligation and were treated with LDE-MTX, or with MTX (1 mg/kg intraperitoneally, once/week, starting 24 hours after surgery) or with LDE without drug (MI-controls). A sham-surgery group (n=12) was also included. Echocardiography was performed 24 hours and 6 weeks after surgery. The animals were euthanized and their hearts were analyzed for morphometry, protein expression, and confocal microscopy.

Results

LDE-MTX treatment achieved a 40% improvement in left ventricular (LV) systolic function and reduced cardiac dilation and LV mass, as shown by echocardiography. LDE-MTX reduced the infarction size, myocyte hypertrophy and necrosis, number of inflammatory cells, and myocardial fibrosis, as shown by morphometric analysis. LDE-MTX increased antioxidant enzymes; decreased apoptosis, macrophages, reactive oxygen species production; and tissue hypoxia in non-infarcted myocardium. LDE-MTX increased adenosine bioavailability in the LV by increasing adenosine receptors and modulating adenosine catabolic enzymes. LDE-MTX increased the expression of myocardial vascular endothelium growth factor (VEGF) associated with adenosine release; this correlated not only with an increase in angiogenesis, but also with other parameters improved by LDE-MTX, suggesting that VEGF increase played an important role in the beneficial effects of LDE-MTX. Overall effects of commercial MTX were minor, and did not improve LV function or infarction size. Both treatments did not induce any toxicity.

Conclusion

The remarkable improvement in heart function and reduction in infarction size achieved by LDE-MTX supports future clinical trials.

MethotrexaTE THerapy in ST-Segment Elevation MYocardial InfarctionS

Purpose:

Methotrexate is an anti-inflammatory drug that has been shown to have anti-ischemic effects. Our aim was to evaluate if methotrexate could reduce infarct size in patients with ST-segment elevation myocardial infarction (STEMI).

Methods:

We randomly assigned patients with STEMI to receive either methotrexate or placebo. Primary outcome was infarct size determined by calculating the area under the curve (AUC) for creatine kinase (CK) release. Secondary outcomes were AUC of CK MB (CK-MB) and AUC of troponin I; peak CK, peak CK-MB, and troponin I; B-type natriuretic peptide (BNP) level, high-sensitivity C-reactive protein (hsCRP) result, and erythrocyte sedimentation rate (ESR); left ventricular ejection fraction (LVEF); thrombolysis in myocardial infarction (TIMI) frame count; Killip score; mortality and reinfarction incidence; and incidence of adverse reactions.

Results:

We included 84 patients. Median AUC of CK was 78 861.0 in the methotrexate group and 68 088.0 in the placebo group ( P = .10). Patients given methotrexate and placebo exhibited, respectively, median AUC for CK-MB of 9803.4 and 8037.0 ( P = .42); median AUC for troponin of 3691.1 and 2132.6 ( P = .09); peak CK of 2806.0 and 2147.0 ( P = .05); peak CK-MB of 516.0 and 462.3 ( P = .25); and peak troponin of 121.0 and 85.1 ( P = .06). At 3 months, LVEF was lower in patients who received methotrexate (49.0% ± 14.1%) than in patients given placebo (56.4% ± 10.0%; P = .01). There were no differences in hsCRP, ESR, BNP, Killip scores, TIMI frame count, reinfarction, and mortality rates. There was a higher median serum glutamic–pyruvic transaminase levels in the methotrexate group.

Conclusion:

Methotrexate did not reduce infarction size and worsened LVEF at 3 months ( Clinicaltrials.gov identifier NCT01741558).

Inflammation and beyond: new directions and emerging drugs for treating atherosclerosis

INTRODUCTION

Cardiovascular (CV) atherosclerotic disease remains the leading cause of morbidity and mortality worldwide, despite the advances in contemporary therapies. Inflammation is an important process in atherosclerosis, leading to plaque rupture and acute coronary syndrome. Although statin therapy has substantially reduced CV events in primary and secondary prevention, many treated patients will have recurrent adverse CV events despite the standard of care. Thus, drug development aiming to target inflammatory pathways seems a promising avenue for novel therapies in atherosclerosis. Areas covered: Statins have been extensively studied and are the most effective lipid-lowering drugs available for CV prevention. Novel anti-inflammatory drugs are being tested in Phase II and III trials, targeting pathways like interleukin-1, leukotrienes, TNF-α, P-selectin, CCL2-CCR2 and MAP Kinase. Expert opinion: Novel anti-inflammatory therapies seem promising additions to address the residual CV risk present despite the current standard of care, but large clinical trials have not yet shown beneficial effects on clinical events. PCSK9 inhibitors have been shown to substantially reduce LDL-C, however their long-term safety and effects on CV risk are currently being investigated. Pharmacogenomics holds great potential in future lipid trials, enabling the identification of patients who will respond with greater benefits and smaller risk to therapies and to decrease failure rates in drug development, as genotype-dependent effects of the CETP inhibitor dalcetrapib were shown in the dal-OUTCOMES and dal-PLAQUE-2 trials.

Inflammatory cytokines in atherosclerosis: current therapeutic approaches

The notion of atherosclerosis as a chronic inflammatory disease has intensified research on the role of cytokines and the way these molecules act and interact to initiate and sustain inflammation in the microenvironment of an atherosclerotic plaque. Cytokines are expressed by all types of cells involved in the pathogenesis of atherosclerosis, act on a variety of targets exerting multiple effects, and are largely responsible for the crosstalk among endothelial, smooth muscle cells, leucocytes, and other vascular residing cells. It is now understood that widely used drugs such as statins, aspirin, methotrexate, and colchicine act in an immunomodulatory way that may beneficially affect atherogenesis and/or cardiovascular disease progression. Moreover, advancement in pharmaceutical design has enabled the production of highly specific antibodies against key molecules involved in the perpetuation of the inflammatory cascade, raising hope for advances in the treatment of atherosclerosis. This review describes the actions and effects of these agents, their potential clinical significance, and future prospects.

Exploiting the Pleiotropic Antioxidant Effects of Established Drugs in Cardiovascular Disease

Cardiovascular disease is a leading cause of death and reduced quality of life worldwide. Arterial vessels are a primary target for endothelial dysfunction and atherosclerosis, which is accompanied or even driven by increased oxidative stress. Recent research in this field identified different sources of reactive oxygen and nitrogen species contributing to the pathogenesis of endothelial dysfunction. According to lessons from the past, improvement of endothelial function and prevention of cardiovascular disease by systemic, unspecific, oral antioxidant therapy are obviously too simplistic an approach. Source- and cell organelle-specific antioxidants as well as activators of intrinsic antioxidant defense systems might be more promising. Since basic research demonstrated the contribution of different inflammatory cells to vascular oxidative stress and clinical trials identified chronic inflammatory disorders as risk factors for cardiovascular events, atherosclerosis and cardiovascular disease are closely associated with inflammation. Therefore, modulation of the inflammatory response is a new and promising approach in the therapy of cardiovascular disease. Classical anti-inflammatory therapeutic compounds, but also established drugs with pleiotropic immunomodulatory abilities, demonstrated protective effects in various models of cardiovascular disease. However, results from ongoing clinical trials are needed to further evaluate the value of immunomodulation for the treatment of cardiovascular disease.

An interaction between glucagon-like peptide-1 and adenosine contributes to cardioprotection of a dipeptidyl peptidase 4 inhibitor from myocardial ischemia-reperfusion injury

Dipeptidyl peptidase 4 (DPP4) inhibitors suppress the metabolism of the potent antihyperglycemic hormone glucagon-like peptide-1 (GLP-1). DPP4 was recently shown to provide cardioprotection through a reduction of infarct size, but the mechanism for this remains elusive. Known interactions between DPP4 and adenosine deaminase (ADA) suggest an involvement of adenosine signaling in DPP4 inhibitor-mediated cardioprotection. We tested whether the protective mechanism of the DPP4 inhibitor alogliptin against myocardial ischemia-reperfusion injury involves GLP-1- and/or adenosine-dependent signaling in canine hearts. In anesthetized dogs, the coronary artery was occluded for 90 min followed by reperfusion for 6 h. A 4-day pretreatment with alogliptin reduced the infarct size from 43.1 ± 2.5% to 17.1 ± 5.0% without affecting collateral flow and hemodynamic parameters, indicating a potent antinecrotic effect. Alogliptin also suppressed apoptosis as demonstrated by the following analysis: 1) reduction in the Bax-to-Bcl2 ratio; 2) cytochrome c release, 3) an increase in Bad phosphorylation in the cytosolic fraction; and 4) terminal deoxynucleotidyl transferase dUTP nick end labeling assay. This DPP4 inhibitor did not affect blood ADA activity or adenosine concentrations. In contrast, the nonselective adenosine receptor blocker 8-(p-sulfophenyl)theophylline (8SPT) completely blunted the effect of alogliptin. Alogliptin did not affect Erk1/2 phosphorylation, but it did stimulate phosphorylation of Akt, glycogen synthase kinase-3β, and cAMP response element-binding protein (CREB). Only 8SPT prevented alogliptin-induced CREB phosphorylation. In conclusion, the DPP4 inhibitor alogliptin suppresses ischemia-reperfusion injury via adenosine receptor- and CREB-dependent signaling pathways.

Role of vascular inflammation in coronary artery disease: potential of anti-inflammatory drugs in the prevention of atherothrombosis. Inflammation and anti-inflammatory drugs in coronary artery disease

Coronary artery disease (CAD) and acute myocardial infarction (AMI) are inflammatory pathologies, involving interleukins (ILs), such as IL-1β, IL-6 and tumor necrosis factor (TNF)-α, and acute phase proteins production, such as for C reactive protein (CRP). The process begins with retention of low-density lipoprotein (LDL) and its oxidation inside the intima, with the formation of the "foam cells." Toll-like receptors and inflamassomes participate in atherosclerosis formation, as well as in the activation of the complement system. In addition to innate immunity, adaptive immunity is also associated with atherosclerosis through antigen-presenting cells, T and B lymphocytes. AMI also increases the expression of some ILs and promotes macrophage and lymphocyte accumulation. Reperfusion increases the expression of anti-inflammatory ILs (such as IL-10) and generates oxygen free radicals. Although CAD and AMI are inflammatory disorders, the only drugs with anti-inflammatory effect so far widely used in ischemic heart disease are aspirin and statins. Some immunomodulatory or immunosuppressive promising therapies, such as cyclosporine and colchicine, may have benefits in CAD. Methotrexate also has potential cardioprotective anti-inflammatory effects, through increased adenosine levels. The TETHYS trial (The Effects of mETHotrexate Therapy on ST Segment Elevation MYocardial InfarctionS trial) will evaluate low-dose methotrexate in ST elevation AMI. The CIRT (Cardiovascular Inflammation Reduction Trial), in turn, will evaluate low-dose methotrexate in patients with a high prevalence of subclinical vascular inflammation. The CANTOS (The Canakinumab Antiinflammatory Thrombosis Outcomes Study) will evaluate canakinumab in patients with CAD and persistently elevated CRP. The blockage of other potential targets, such as the IL-6 receptor, CC2 chemokine receptor and CD20, could bring benefits in CAD.

The effect of eplerenone on adenosine formation in humans in vivo: a double-blinded randomised controlled study

Background

It has been suggested that mineralocorticoid receptor antagonists have direct cardioprotective properties, because these drugs reduce mortality in patients with heart failure. In murine models of myocardial infarction, mineralocorticoid receptor antagonists reduce infarct size. Using gene deletion and pharmacological approaches, it has been shown that extracellular formation of the endogenous nucleoside adenosine is crucial for this protective effect. We now aim to translate this finding to humans, by investigating the effects of the selective mineralocorticoid receptor antagonist eplerenone on the vasodilator effect of the adenosine uptake inhibitor dipyridamole, which is a well-validated surrogate marker for extracellular adenosine formation.

Methods and Results

In a randomised, double-blinded, placebo-controlled, cross-over study we measured the forearm blood flow response to the intrabrachial administration of dipyridamole in 14 healthy male subjects before and after treatment with placebo or eplerenone (50 mg bid for 8 days). The forearm blood flow during administration of dipyridamole (10, 30 and 100 µg·min⁻¹·dl⁻¹) was 1.63 (0.60), 2.13 (1.51) and 2.71 (1.32) ml·dl⁻¹·min⁻¹ during placebo use, versus 2.00 (1.45), 2.68 (1.87) and 3.22 (1.94) ml·dl⁻¹·min⁻¹ during eplerenone treatment (median (interquartile range); P = 0.51). Concomitant administration of the adenosine receptor antagonist caffeine attenuated dipyridamole-induced vasodilation to a similar extent in both groups. The forearm blood flow response to forearm ischemia, as a stimulus for increased formation of adenosine, was similar during both conditions.

Conclusion

In a dosage of 50 mg bid, eplerenone does not augment extracellular adenosine formation in healthy human subjects. Therefore, it is unlikely that an increased extracellular adenosine formation contributes to the cardioprotective effect of mineralocorticoid receptor antagonists.

Trial Registration

ClinicalTrials.gov, NCT01837108

Endothelial Cx40 limits myocardial ischaemia/reperfusion injury in mice

AIMS

Gap junctions are indispensable for the function of heart and blood vessels by providing electrical coupling and direct cell-to-cell transfer of small signalling molecules. Gap junction channels between neighbouring cells are composed of 12 connexins (Cx). Changes in Cx43 expression, localization, and channel properties in cardiomyocytes contribute to infarction and reperfusion injury of the heart. It is increasingly recognized that deleterious consequences of ischaemia/reperfusion (IR) are modulated by the inflammatory response and endothelial function. The role of the endothelial connexins, i.e. Cx40 and Cx37, in cardiac IR injury is, however, not known.

METHODS AND RESULTS

Following 30 min ischaemia and 24 h reperfusion, we found a significant increase in myocardial infarct size in mice with endothelial-specific deletion of Cx40 (Cx40del), but not in Cx37-deficient mice. The cardioprotective effect of endothelial Cx40 was associated with a decrease in neutrophil infiltration. Moreover, beneficial effects of endothelial Cx40 were not observed in isolated Langendorff-perfused hearts, suggesting direct involvement of endothelial-leucocyte interactions in the cardiac injury. Single-dose administration of methotrexate, a CD73 activator, reduced infarct size and neutrophil infiltration into the infarcted myocardium in Cx40del but not in control mice. Similar to Cx40del mice, CD73-deficient mice showed increased sensitivity to cardiac IR injury, which could not be conversed by methotrexate.

CONCLUSION

Endothelial Cx40, but not Cx37, is implicated in resistance of the heart to IR injury by activation of the CD73 pathway. Thus, the Cx40-CD73 axis may represent an interesting target for controlling reperfusion damage associated with revascularization in coronary disease.

Targeting adenosine receptors in the development of cardiovascular therapeutics

Adenosine receptor stimulation has negative inotropic and dromotropic actions, reduces cardiac ischemia-reperfusion injury and remodeling, and prevents cardiac arrhythmias. In the vasculature, adenosine modulates vascular tone, reduces infiltration of inflammatory cells and generation of foam cells, and may prevent the development of atherosclerosis as a result. Modulation of insulin sensitivity may further add to the anti-atherosclerotic properties of adenosine signaling. In the kidney, adenosine plays an important role in tubuloglomerular feedback and modulates tubular sodium reabsorption. The challenge is to take advantage of the beneficial actions of adenosine signaling while preventing its potential adverse effects, such as salt retention and sympathoexcitation. Drugs that interfere with adenosine formation and elimination or drugs that allosterically enhance specific adenosine receptors seem to be most promising to meet this challenge.

The effects of METhotrexate therapy on the physical capacity of patients with ISchemic heart failure: a randomized double-blind, placebo-controlled trial (METIS trial)

BACKGROUND

The cytokine hypothesis suggests that there is an association between chronic heart failure (CHF) and inflammation. Methotrexate could improve CHF patients' clinical status, especially those with ischemic etiology.

METHODS AND RESULTS

METIS is a randomized, double-blinded trial studying 50 patients with ischemic CHF given methotrexate (7.5mg) or placebo, plus folic acid (5mg), for 12 weeks. The primary end point was the difference in 6-minute walk test (6MWT) distance before and after treatment. We also evaluated functional class (NYHA), Short-Form 36 protocol quality of life, C-reactive protein (CRP), incidence of adverse effects, and the combined incidence of death, myocardial infarction, stroke, hospitalization, and need for myocardial revascularization. There was no significant difference between groups in distance covered in the 6MWT: the methotrexate group improved by 24.5+/-39.5m, the placebo group by 21.3+/-43.7m (P=.80). The NYHA scores improved in 66.7% of the methotrexate group patients and in 50.0% of the placebo group (P=.2). SF-36 scores indicated improved mental health in the placebo group. There were no significant differences in CRP levels, the combined outcome, or adverse events.

CONCLUSIONS

These results show that the methotrexate group tended toward improved NYHA scores and that there were no significant changes in 6MWT results or secondary assessments.

Activation of immune and inflammatory systems in chronic heart failure: novel therapeutic approaches

Despite extensive research and novel treatments, chronic heart failure (CHF) remains a cause of high morbidity and mortality. Mounting evidence suggested that immune activation and inflammation play critical roles in the pathogenesis of CHF. In this review, we examine the current evidence regarding this contemporary pathophysiological mechanism, and evaluate the effects of conventional and novel cardiovascular drugs, such as calcium sensitisers and statins, on the immune and inflammatory mediator's network. Although therapies, which specifically antagonise tumour necrosis factor-alpha have not demonstrated considerable benefit in patients with CHF, there is an increasing evidence to suggest greater value from non-specific anti-inflammatory approaches, including: pentoxifylline, intravenous immunoglobulin, immune modulation therapy, growth hormones, physical training and nutrition regulation. Several innovative therapeutic targets, such as peroxisome proliferator-activated receptor gamma activators, Rho-kinase, p38 mitogen-activated protein kinase, nuclear transcription factor NF-kappaB, recovering or augmenting parasympathetic tone, cardiac resynchronisation therapy, macrophage inhibitors and chemokine receptor antagonists, are briefly discussed in this review. While we have recently demonstrated the potential merits of combining low-dose methotrexate with conventional therapy, through extensively modulating the activated immune and inflammatory mediator's network, there is a need for further rigorous research of this complex network, especially involving current promising therapies which modulate this system. Such evidence has the potential to revolutionise changes for the management of this disorder. Based on the 'heterogeneity' of immune activation and inflammation among different CHF populations, an 'optimised combination treatment' may offer exciting benefits for individual therapy in the future.

Synthesis, antiproliferative and antifungal activities of some 2-(2,4-dihydroxyphenyl)-4H-3,1-benzothiazines

A new method for the synthesis of 4H-3,1-benzothiazine skeleton is described. The compounds were obtained by the reaction of sulfinylbis(2,4-dihydroxythiobenzoyl) with o-substituted anilines bearing an activated methylene group (-CH2OH, -CH2NR1R2), o-aminobenzanilides or 2-aminobenzophenones. The reaction proceeded through thiobenzanilide intermediates, which were converted to the 4H-3,1-benzothiazine fused ring by an endocyclization process. The compounds were tested for their antiproliferative properties against the cells of a human breast cancer T47D line. The activity of some compounds was comparable to that of cisplatin, studied as a control. A strong antifungal effect against the strains of moulds, yeasts and dermatophytes was also found.

Methotrexate modulates the kinetics of adenosine in humans in vivo

BACKGROUND

Animal studies suggest that the anti-inflammatory effect of methotrexate (MTX) is mediated by increased adenosine concentrations.

OBJECTIVE

To assess the effect of MTX on the vasodilator effects of adenosine and the nucleoside uptake inhibitor, dipyridamole, in humans in vivo as a marker for changes in adenosine kinetics.

METHODS

Ten patients with active arthritis were treated with MTX (15 mg/week). Measurements were performed before and after 12 weeks of treatment. At these time points, the activity of adenosine deaminase was measured in isolated lymphocytes, and forearm blood flow (FBF) was determined by venous occlusion plethysmography during administration of adenosine and dipyridamole into the brachial artery.

RESULTS

The Vmax of adenosine deaminase in lymphocytes was reduced by MTX treatment (p<0.05). MTX significantly enhanced vasodilator response to adenosine (0.5 and 1.5 microg/min/dl of forearm tissue; mean (SE) FBF ratio increased from 1.2 (0.2) to 1.4 (0.2) and 2.2 (0.2) ml/dl/min, respectively, before and from 1.3 (0.1) to 1.8 (0.2) and 3.2 (0.5) ml/dl/min during MTX treatment; p<0.05). Also, dipyridamole-induced vasodilatation (30 and 100 microg/min/dl) was enhanced by MTX (FBF ratio increased from 1.2 (0.2) to 1.5 (0.3) and 1.8 (0.2), respectively, before and from 1.3 (0.1) to 1.8 (0.2) and 2.4 (0.4) during MTX treatment; p<0.05).

CONCLUSIONS

MTX treatment inhibits deamination of adenosine and potentiates adenosine-induced vasodilatation. Also dipyridamole-induced vasodilatation is enhanced by MTX treatment, suggesting an increased extracellular formation of adenosine. These effects on the adenosine kinetics in humans may contribute to the therapeutic efficacy of MTX.

The 5'-nucleotidases as regulators of nucleotide and drug metabolism

The 5'-nucleotidases are a family of enzymes that catalyze the dephosphorylation of nucleoside monophosphates and regulate cellular nucleotide and nucleoside levels. While the nucleoside kinases responsible for the initial phosphorylation of salvaged nucleosides have been well studied, many of the catabolic nucleotidases have only recently been cloned and characterized. Aside from maintaining balanced ribo- and deoxyribonucleotide pools, substrate cycles that are formed with kinase and nucleotidase activities are also likely to regulate the activation of nucleoside analogues, a class of anticancer and antiviral agents that rely on the nucleoside kinases for phosphorylation to their active forms. Both clinical and in vitro studies suggest that an increase in nucleotidase activity can inhibit nucleoside analogue activation and result in drug resistance. The physiological role of the 5'-nucleotidases will be covered in this review, as will the evidence that these enzymes can mediate resistance to nucleoside analogues.