Methotrexate inhibits proliferation and regulation of the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 by cultured human umbilical vein endothelial cells

The actions of methotrexate on endothelial cells are dependent on the shear stress-induced regulation of one carbon metabolism

Objectives

The disease-modifying anti-rheumatic drug methotrexate (MTX) is recognized to reduce cardiovascular risk in patients with systemic inflammatory diseases. However, the molecular basis for these cardioprotective effects remains incompletely understood. This study evaluated the actions of low-dose MTX on the vascular endothelium.

Methods

Human endothelial cells (EC) were studied under in vitro conditions relevant to inflammatory arthritis. These included culture in a pro-inflammatory microenvironment and exposure to fluid shear stress (FSS) using a parallel plate model. Respectively treated cells were analyzed by RNA sequencing and quantitative real-time PCR for gene expression, by immunoblotting for protein expression, by phosphokinase activity arrays, by flow cytometry for cell cycle analyses and by mass spectrometry to assess folate metabolite levels.

Results

In static conditions, MTX was efficiently taken up by EC and caused cell cycle arrest concurrent with modulation of cell signaling pathways. These responses were reversed by folinic acid (FA), suggesting that OCM is a predominant target of MTX. Under FSS, MTX did not affect cell proliferation or pro-inflammatory gene expression. Exposure to FSS downregulated endothelial one carbon metabolism (OCM) as evidenced by decreased expression of key OCM genes and metabolites.

Conclusion

We found that FSS significantly downregulated OCM and thereby rendered EC less susceptible to the effects of MTX treatment. The impact of shear stress on OCM suggested that MTX does not directly modulate endothelial function. The cardioprotective actions of MTX likely reflect direct actions on inflammatory cells and indirect benefit on the vascular endothelium.

Methotrexate and cardiovascular prevention: an appraisal of the current evidence

New evidence continues to accumulate regarding a significant association between excessive inflammation and dysregulated immunity (local and systemic) and the risk of cardiovascular events in different patient cohorts. Whilst research has sought to identify novel atheroprotective therapies targeting inflammation and immunity, several marketed drugs for rheumatological conditions may serve a similar purpose. One such drug, methotrexate, has been used since 1948 for treating cancer and, more recently, for a wide range of dysimmune conditions. Over the last 30 years, epidemiological and experimental studies have shown that methotrexate is independently associated with a reduced risk of cardiovascular disease, particularly in rheumatological patients, and exerts several beneficial effects on vascular homeostasis and blood pressure control. This review article discusses the current challenges with managing cardiovascular risk and the new frontiers offered by drug discovery and drug repurposing targeting inflammation and immunity with a focus on methotrexate. Specifically, the article critically appraises the results of observational, cross-sectional and intervention studies investigating the effects of methotrexate on overall cardiovascular risk and individual risk factors. It also discusses the putative molecular mechanisms underpinning the atheroprotective effects of methotrexate and the practical advantages of using methotrexate in cardiovascular prevention, and highlights future research directions in this area.

A novel personalised treatment approach for psoriasis: anti-VEGF-A therapy

Chronic plaque psoriasis is an inflammatory skin disease in which genetic predisposition along with environmental factors lead to the development of the disease, which affects 2% of the UK’s population and is associated with extracutaneous morbidities and a reduced quality of life. A complex crosstalk between innate and adaptive immunity, the epithelia and the vasculature maintain the inflammatory milieu in psoriasis. Despite the development of promising treatment strategies, mostly targeting the immune system, treatments fail to fulfil every patient’s goals. Vascular endothelial growth factor‐A (VEGF‐A) mediates angiogenesis and is upregulated in the plaques and plasma of patients with psoriasis. Transgenic expression of VEGF‐A in experimental models led to the development of skin lesions that share many psoriasis features. Targeting VEGF‐A in in vivo models of psoriasis‐like inflammation resulted in disease clearance. Anti‐angiogenesis treatments are widely used for cancer and eye disease and there are clinical reports of patients treated with VEGF‐A inhibitors who have experienced Psoriasis Area and Severity Index improvement. Existing psoriasis treatments downregulate VEGF‐A and angiogenesis as part of their therapeutic effect. Pharmacogenetics studies suggest the existence of different genetic signatures within patients with psoriasis that correspond with different treatment responsiveness and disease severity. There is a subset of patients with psoriasis with an increased predisposition to produce high levels of VEGF‐A, who may be most likely to benefit from anti‐VEGF‐A therapy, offering an opportunity to personalize treatment in psoriasis. Anti‐VEGF‐A therapies may offer an alternative to existing anticytokine strategies or be complementary to standard treatments for the management of psoriasis.

Angiogenesis as a potential treatment strategy for rheumatoid arthritis

Angiogenesis is an early and key event in the pathogenesis of rheumatoid arthritis (RA) and is crucial for the proliferation of synovial tissue and the formation of pannus. This process is regulated by both angiogenesis-stimulating factors and angiogenesis inhibitors, the basis for the "on-off hypothesis of angiogenesis." In RA, inflammation, immune imbalance, and hypoxia can further turn on the switch for blood vessel formation and induce angiogenesis. The new vasculature can recruit white blood cells, induce immune imbalance, and aggravate inflammation. At the same time, it also can provide oxygen and nutrients for the proliferating synovial tissue, which can accelerate the process of RA. The current therapies for RA mainly target the inflammatory response of autoimmune activation. Although these therapies have been greatly improved, there are still many patients whose RA is difficult to treat or who do not fully respond to treatment. Therefore, new innovative therapies are still urgently needed. This review covers the mechanism of synovial angiogenesis in RA, including the detailed process of angiogenesis and the relationship between inflammation, immune imbalance, hypoxia, and synovial angiogenesis, respectively. At the same time, in the context of the development of angiogenesis inhibition therapy for cancer, we also discuss similar treatment strategies for RA, especially the combination of targeted angiogenesis inhibition therapy and immunotherapy.

Implications of narrowband ultraviolet B treatment on psoriasis severity and serum levels of angiopoietin-2: A cross-sectional controlled study

BACKGROUND

Psoriasis is a chronic inflammatory hyper proliferative skin disease. Angiogenesis play an important role in Psoriasis pathogenesis, occurring even before plaque formation. Angiopoietins play an important role in angiogenesis and hence are described as angiogenic factors.

AIMS

To evaluate serum levels of angiopoeitin 2 (Ang-2) following treatment with narrowband ultraviolet B (NBUVB) in patients with moderate-severe plaque psoriasis and correlate it to psoriasis area and severity index (PASI).

PATIENTS/METHODS

This cross sectional study included 38 patients complaining of moderate to severe plaque psoriasis and 38 healthy controls. Psoriasis area and severity index (PASI) was determined and was correlated to serum levels of Ang-2 before and after treatment with NBUVB.

RESULTS

PASI scores and serum values of angiopoietin 2 demonstrated a significant difference between the baseline and at the end of the 12 weeks NBUVB treatment. A statistically significant positive correlation was established between psoriasis severity and Ang-2 serum levels before and after treatment.

CONCLUSION

The study demonstrated a potential contribution of Ang-2 in the pathogenesis of psoriasis, as well as its usefulness as a biomarker of psoriasis severity.

Endothelial cell and T-cell crosstalk: Targeting metabolism as a therapeutic approach in chronic inflammation

The role of metabolic reprogramming in the coordination of the immune response has gained increasing consideration in recent years. Indeed, it has become clear that changes in the metabolic status of immune cells can alter their functional properties. During inflammation, T cells need to generate sufficient energy and biomolecules to support growth, proliferation, and effector functions. Therefore, T cells need to rearrange their metabolism to meet these demands. A similar metabolic reprogramming has been described in endothelial cells, which have the ability to interact with and modulate the function of immune cells. In this overview, we will discuss recent insights in the complex crosstalk between endothelial cells and T cells as well as their metabolic reprogramming following activation. We highlight key components of this metabolic switch that can lead to the development of new therapeutics against chronic inflammatory disorders. LINKED ARTICLES: This article is part of a themed issue on Cellular metabolism and diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.10/issuetoc.

Methotrexate attenuates vascular inflammation through an adenosine-microRNA-dependent pathway

Endothelial cell (EC) activation is an early hallmark in the pathogenesis of chronic vascular diseases. MicroRNA-181b (Mir181b) is an important anti-inflammatory mediator in the vascular endothelium affecting endotoxemia, atherosclerosis, and insulin resistance. Herein, we identify that the drug methotrexate (MTX) and its downstream metabolite adenosine exert anti-inflammatory effects in the vascular endothelium by targeting and activating Mir181b expression. Both systemic and endothelial-specific Mir181a2b2-deficient mice develop vascular inflammation, white adipose tissue (WAT) inflammation, and insulin resistance in a diet-induced obesity model. Moreover, MTX attenuated diet-induced WAT inflammation, insulin resistance, and EC activation in a Mir181a2b2-dependent manner. Mechanistically, MTX attenuated cytokine-induced EC activation through a unique adenosine-adenosine receptor A3-SMAD3/4-Mir181b signaling cascade. These findings establish an essential role of endothelial Mir181b in controlling vascular inflammation and that restoring Mir181b in ECs by high-dose MTX or adenosine signaling may provide a potential therapeutic opportunity for anti-inflammatory therapy.

Vascular endothelial growth factor-A as a promising therapeutic target for the management of psoriasis

Vascular endothelial growth factor-A (VEGF-A), the main angiogenic mediator, plays a critical role in the pathogenesis of several inflammatory immune-mediated diseases, including psoriasis. Even though anti-angiogenic therapies, such as VEGF inhibitors, are licensed for the treatment of various cancers and eye disease, VEGF-targeting interventions are not part of current psoriasis therapy. In this viewpoint essay, we argue that the existing preclinical research evidence on the role of VEGF-A in the pathogenesis of psoriasis as well as clinical observations in patients who have experienced psoriasis remission during oncological anti-VEGF-A therapy strongly suggests to systematically explore angiogenesis targeting also in the management of psoriasis. We also point out that some psoriasis therapies decrease circulating levels of VEGF-A and normalise the psoriasis-associated vascular pathology in the papillary dermis of plaques of psoriasis and that a subset of patients with constitutionally high levels of VEGF-A may benefit most from the anti-angiogenic therapy we advocate here. Given that novel, well-targeted personalised medicine therapies for the development of psoriasis need to be developed, we explore the hypothesis that VEGF-A and signalling through its receptors constitute a promising target for therapeutic intervention in the future management of psoriasis.

Evaluation of microvessel density with CD31 and CD105 in patients with psoriasis under methotrexate and acitretin therapy

Introduction

Methotrexate and acitretin are known to be effective in the treatment of psoriasis, but the mechanisms of the effects of these drugs are not fully known.

Aim

To investigate the effect of methotrexate and acitretin on microvessel density (MVD) in psoriasis.

Material and methods

Eighteen patients with psoriasis treated with methotrexate and 9 patients with psoriasis treated with acitretin (AT) were included in this study. MVD was evaluated immunohistochemically by using CD31 and CD105 (endoglin) antibodies.

Results

In the methotrexate group, the decrease in CD31 levels after treatment was found to be statistically significant, while in the AT group it was found to be highly significant. In both methotrexate and AT group, there was a statistically highly significant decrease in CD105 levels after treatment. There was no statistically significant difference between CD31 measurements of methotrexate and AT groups. When CD105 levels were measured before and after treatment, no statistically significant difference was found between methotrexate and AT. According to the results of CD31 changes before and after treatment, the CD31 difference was not statistically significant in both groups while the difference was higher in the AT group. CD105 differences were not statistically significant in both treatment groups before and after treatment.

Conclusions

CD31 and CD105 dyes indicate the effects of therapies on vascular proliferation and may be indicators that can be used in daily routine and follow-up studies for psoriasis.

Accelerated Atherosclerosis in Rheumatoid Arthritis: Mechanisms and Treatment

Background:

Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disorder that increases the risk of developing cardiovascular disease. There is accumulating evidence that the RA disease state accelerates the formation of atherosclerotic plaques. Treatments for RA improve joint symptomatology and may reduce inflammation, but consideration of their effects on the cardiovascular system is generally low priority.

Objective:

Since cardiovascular disease is the leading cause of mortality in RA patients, the impact of RA therapies on atherosclerosis is an area in need of attention and the focus of this review.

Results:

The drugs used to treat RA may be analgesics, conventional disease-modifying anti-rheumatic drugs, and/or biologics, including antibodies against the cytokine tumor necrosis factor-α. Pain relievers such as nonselective non-steroidal anti-inflammatory drugs and cyclooxygenase inhibitors may adversely affect lipid metabolism and cyclooxygenase inhibitors have been associated with increased adverse cardiovascular events, such as myocardial infarction and stroke. Methotrexate, the anchor disease-modifying anti-rheumatic drug in RA treatment has multiple atheroprotective advantages and is often combined with other therapies. Biologic inhibitors of tumor necrosis factor-α may be beneficial in preventing cardiovascular disease because tumor necrosis factor-α promotes the initiation and progression of atherosclerosis. However, some studies show a worsening of the lipid profile in RA with blockade of this cytokine, leading to higher total cholesterol and triglycerides.

Conclusion:

Greater understanding of the pharmacologic activity of RA treatments on the atherosclerotic process may lead to improved care, addressing both damages to the joints and heart.

Repurposing existing drugs for cardiovascular risk management: a focus on methotrexate

About 20% of patients with a history of atherosclerotic cardiovascular disease will experience further cardiovascular events despite maximal pharmacological treatment with cardioprotective drugs. This highlights the presence of residual cardiovascular risk in a significant proportion of patients and the need for novel, more effective therapies. These therapies should ideally target different pathophysiological pathways involved in the onset and the progression of atherosclerosis, particularly the inflammatory and immune pathways. Methotrexate is a first-line disease-modifying antirheumatic drug that is widely used for the management of autoimmune and chronic inflammatory disorders. There is some in vitro and in vivo evidence that methotrexate might exert a unique combination of anti-inflammatory, blood pressure lowering, and vasculoprotective effects. Pending the results of large prospective studies investigating surrogate end-points as well as morbidity and mortality, repurposing methotrexate for cardiovascular risk management might represent a cost-effective strategy with immediate public health benefits. This review discusses the current challenges in the management of cardiovascular disease; the available evidence on the effects of methotrexate on inflammation, blood pressure, and surrogate markers of arterial function; suggestions for future research directions; and practical considerations with the use of methotrexate in this context.

Analysis of Drug Effects on Primary Human Coronary Artery Endothelial Cells Activated by Serum Amyloid A

Background

RA patients have a higher incidence of cardiovascular diseases compared to the general population. Serum amyloid A (SAA) is an acute-phase protein, upregulated in sera of RA patients.

Aim

To determine the effects of medications on SAA-stimulated human coronary artery endothelial cells (HCAEC).

Methods

HCAEC were preincubated for 2 h with medications from sterile ampules (dexamethasone, methotrexate, certolizumab pegol, and etanercept), dissolved in medium (captopril) or DMSO (etoricoxib, rosiglitazone, meloxicam, fluvastatin, and diclofenac). Human recombinant apo-SAA was used to stimulate HCAEC at a final 1000 nM concentration for 24 hours. IL-6, IL-8, sVCAM-1, and PAI-1 were measured by ELISA. The number of viable cells was determined colorimetrically.

Results

SAA-stimulated levels of released IL-6, IL-8, and sVCAM-1 from HCAEC were significantly attenuated by methotrexate, fluvastatin, and etoricoxib. Both certolizumab pegol and etanercept significantly decreased PAI-1 by an average of 43%. Rosiglitazone significantly inhibited sVCAM-1 by 58%.

Conclusion

We observed marked influence of fluvastatin on lowering cytokine production in SAA-activated HCAEC. Methotrexate showed strong beneficial effects for lowering released Il-6, IL-8, and sVCAM-1. Interesting duality was observed for NSAIDs, with meloxicam exhibiting opposite-trend effects from diclofenac and etoricoxib. This represents unique insight into specific responsiveness of inflammatory-driven HCAEC relevant to atherosclerosis.

Protective Effects of Methotrexate against Proatherosclerotic Cytokines: A Review of the Evidence

There is good epidemiological evidence that patients with autoimmune rheumatic disease states, particularly rheumatoid arthritis, have an increased risk of cardiovascular morbidity and mortality when compared to the general population. The presence of a chronic systemic proinflammatory state in this patient group disrupts the structural and functional integrity of the endothelium and the arterial wall, favouring the onset and progression of atherosclerosis. A significant role in the detrimental effects of inflammation on endothelial function and vascular homeostasis is played by specific proatherosclerotic cytokines such as tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6). Recent systematic reviews and meta-analyses have shown that treatment with methotrexate, a first-line disease-modifying antirheumatic drug (DMARD), is associated with a significant reduction in atherosclerosis-mediated cardiovascular events, such as myocardial infarction and stroke, and mortality, when compared to other DMARDs. This suggests that methotrexate might exert specific protective effects against vascular inflammation and atherosclerosis in the context of autoimmune rheumatic disease. This review discusses the available evidence regarding the potential antiatherosclerotic effects of methotrexate through the inhibition of TNF-α, IL-1, and IL-6 and provides suggestions for future experimental and human studies addressing this issue.

Soluble vascular endothelial (VE) cadherin and autoantibodies to VE-cadherin in rheumatoid arthritis patients treated with etanercept or adalimumab

OBJECTIVES

The aim of this study was to investigate the clinical value of sVE and anti-vascular endothelial-cadherin antibodies (AAVE) in RA treated with etanercept or adalimumab combined with methotrexate.

METHODS

This was an 18-month prospective multicenter study in which patients had active RA, requiring TNF antagonist. sVE rates and AAVE titers were measured respectively by dot blot and ELISA. The relationship of these biomarkers with parameters reflecting articular or systemic disease activity, progression of structural damage, and response or remission to treatment was analyzed.

RESULTS

Forty-eight patients received TNF blocking agents. Variation of sVE rates were significantly correlated with that of C-reactive protein (CRP) levels at weeks 6, 12, 26 and 52. A significant decrease in sVE levels was observed in the group of patients exhibiting a decrease in CRP levels as compared to the patient group with unmodified CRP. AAVE at baseline were correlated with rheumatoid factor. Kinetics analysis of sVE levels and AAVE titers showed that their level were not associated with disease activity score and to methotrexate/adalimumab or etanercept response.

CONCLUSIONS

sVE is a biomarker associated with systemic RA activity under anti-TNF. AAVE are related to autoantibodies usually associated to RA.

Insights on methotrexate in psoriatic disease

The folic acid analogue methotrexate is used as an anti-neoplastic agent and treatment for inflammatory disorders including psoriasis, dermatomyositis, lupus erythematous, sarcoidosis, and systemic sclerosis. Despite the introduction of newer biologic agents, methotrexate remains a first-line systemic therapy for many patients with disorders of chronic inflammation. Here we briefly describe the current clinical evidence for methotrexate use in psoriatic disease, our current understanding of methotrexate's anti-inflammatory properties, and the future role of methotrexate in the treatment of immune mediated disorders.

Antiangiogenic effect of methotrexate and PUVA on psoriasis

Vascular endothelial growth factor (VEGF) is important factor for angiogenesis in psoriasis. Methotrexate and psoralen and ultraviolet light A (PUVA) mainly target the T cell-mediated immunopathology of psoriasis. Our work aimed at estimating VEGF mRNA in psoriatic patients and investigating whether the standard therapeutic modalities (methotrexate and PUVA) exert their antiangiogenic activity through altering VEGF levels. Twenty-four chronic plaque psoriasis patients were enrolled. Patients were divided into two groups (12 patients each); group A received intramuscular methotrexate and group B was treated by PUVA three times/week in a PUVA 1000 cabin for 10 weeks each. Twelve healthy volunteers served as controls. A skin biopsy was taken from lesional skin before and after treatment for RT-PCR detection of VEGF mRNA. Capillary perfusion scanning using LASER Doppler perfusion imaging was performed on the same psoriatic plaque before and after treatment and was also done for the controls. Following both methotrexate and PUVA, a significant reduction in the amount of VEGF mRNA (P < 0.001 and P = 0.002, respectively) and capillary perfusion (P = 0.002) occurred. These reductions were significantly higher in the methotrexate group (P < 0.001 and  P = 0.001, respectively) than in the PUVA group. The percentage of clinical improvement in the examined psoriatic plaque was significantly positively correlated with the percentage of reduction in the amount of VEGF mRNA (r = 0.850, P < 0.001) and the percentage of reduction in the capillary perfusion (r = 0.684, P < 0.001). Both modalities may exert an antiangiogenic effect. Methotrexate appears to have possibly a more potent antiangiogenic effect than PUVA.

In vitro inhibition of HUVECs by low dose methotrexate - insights into oral adverse events

Background

With socio-economic changes, dentists and maxillofacial surgeons are more and more faced with medically compromised patients. Especially, the admission of antirheumatic drugs has increased remarkably. So dentists and maxillofacial surgeons should be aware of related adverse reactions that affect the craniofacial region. To identify possible cellular effects of disease modifying antirheumatic drugs (DMARDs) we investigated the influence of methotrexate (MTX) on human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were incubated with various concentrations of MTX, corresponding to serum concentrations found in rheumatoid arthritis (RA) patients. The effect of MTX on cell proliferation, differentiation as well as mitochondrial activity was measured by use of immunostaining, cell counting and 3-(4, 5-dimethylthiazol-2-yl)- 2, 5-diphenyltetrazolium bromide (MTT) assay.

Results

All samples incubated with MTX (1-1000 nM) showed significantly decreased cell viability when compared to controls. Cells were less proliferating, but did not lose their ability to synthesize endothelial proteins. A slight dose dependency of inhibiting effects was demonstrated. The observed differences between control and sample groups were rising with longer duration.

Conclusion

Because of the crucial role of endothelial cells and their precursor cells in wound healing, a negative influence of MTX on oral health has to be supposed, correlating to clinical observations of adverse reactions in the oral cavity, such as ulcerative or erosive lesions.

Serum interleukin-6 levels in response to methotrexate treatment in psoriatic patients

BACKGROUND

Psoriasis is a chronic autoimmune hyperproliferative skin disease. In psoriasis, the cutaneous and systemic overexpression of various proinflammatory cytokines, such as interleukin-6 (IL-6) has been demonstrated. Methotrexate (MTX) has been used in the treatment of psoriasis. The aim of this study is to assess the effect of MTX on serum IL-6 levels and also to find the association between PASI score and IL-6 levels in psoriatic patients during MTX therapy.

METHODS

We recruited 20 control subjects and 22 Psoriasis vulgaris patients for this study. The patients were treated with 7.5mg of methotrexate per week for 12 weeks. Folic acid was given at 5mg once daily except on the day of MTX for 12 weeks. There were 2 dropouts, because of increased liver enzyme levels. Blood samples were collected at three intervals (i.e., Day 0, 6 weeks, 12 weeks) from psoriatic patients and only once from control subjects. PASI score, biochemical and hematological parameters were assessed. Serum IL-6 level was analyzed by using ELISA.

RESULTS

Biochemical and hematological parameters showed no significant changes. Serum IL-6 level and PASI score declined significantly (p<0.001) from Day 0 to 12 weeks of MTX treatment and also showed positive correlation before (r=0.992; p<0.000) and after (r=0.987; p<0.000) treatment with MTX. Out of 4 clinical indices of PASI, only 2 indices namely Infiltration (I) and Desquamation (D) showed positive correlation with IL-6 before and after MTX treatment.

CONCLUSION

The treatment response with MTX in psoriatic patients can be seen both at clinical and molecular levels.

Inhibitory effect of indigo naturalis on tumor necrosis factor-α-induced vascular cell adhesion molecule-1 expression in human umbilical vein endothelial cells

The use of indigo naturalis to treat psoriasis has proved effective in our previous clinical studies. The present study was designed to examine the anti-inflammatory effect of indigo naturalis in primary cultured human umbilical vein endothelial cells (HUVECs). Pretreatment of cells with indigo naturalis extract attenuated TNF-α-induced increase in Jurkat T cell adhesion to HUVECs as well as decreased the protein and messenger (m)RNA expression levels of vascular cell adhesion molecule-1 (VCAM-1) on HUVECs. Indigo naturalis extract also inhibited the protein expression of activator protein-1 (AP-1)/c-Jun, a critical transcription factor for the activation of VCAM-1 gene expression. Since the reduction of lymphocyte adhesion to vascular cells by indigo naturalis extract could subsequently reduce the inflammatory reactions caused by lymphocyte infiltration in the epidermal layer and help to improve psoriasis, this study provides a potential mechanism for the anti-inflammatory therapeutic effect of indigo naturalis extract in psoriasis.

Angiogenesis drives psoriasis pathogenesis

Psoriasis pathogenesis is closely associated with disease-inducing Th1 and Th17 cells. Yet, several studies suggest that aberrant keratinocyte or endothelial cell signalling significantly contributes to disease manifestation. Histological hallmarks of psoriatic skin include the infiltration of multiple immune cells, keratinocyte proliferation and increased dermal vascularity. Formation of new blood vessels starts with early psoriatic changes and disappears with disease clearance. Several angiogenic mediators like vascular endothelial growth factor, hypoxia-inducible factors, angiopoietins and pro-angiogenic cytokines, such as tumour necrosis factor (TNF), interleukin (IL)-8 and IL-17, are up-regulated in psoriasis development. Contact- and mediator-dependent factors derived from keratinocytes, mast cells and immune cells may contribute to the strong blood vessel formation of psoriasis. New technologies and experimental models provide new insights into the role of angiogenesis in psoriasis pathogenesis. Interestingly, many therapies target not only immune cells, but also protein structures of endothelial cells. Here we summarize the role of pro-angiogenic factors in psoriasis development and discuss angiogenesis as a potential target of novel therapies.

Comparison of 2-Methoxyestradiol and Methotrexate Effects on Non-Hodgkin's B-Cell Lymphoma

PURPOSE

Methotrexate (MTX) is the most commonly used chemotherapeutic agent to treat primary central nervous system lymphoma (PCNSL) and intraocular lymphoma (IOL). 2-methoxyestradiol (2ME2) is a potent antitumor and anti-angiogenesis agent which, unlike other cytotoxic drugs, has minimal toxicity. In this study, anti-proliferative, apoptotic, and cell-cycle effects of 2ME2 and MTX were compared to evaluate 2ME2 efficacy in human lymphoma cells, models for non-Hodgkin B cell lymphomas.

METHODS

The cells were cultured and incubated with varying concentrations of 2ME2 or MTX. A tetrazolium-based colorimetric assay was used to quantify the anti-proliferative effects of 2ME2 and MTX using a microplate reader. To detect apoptotic and cell cycle distribution changes induced by 2ME2 and MTX, the cells were stained with Annexin V-FITC and/or propidium iodide (PI) and analyzed by flow cytometry.

RESULTS

Lymphoma cell proliferation was inhibited by 50% at concentrations ranging from 0.4 to 1 microM for 2ME2 and 0.06 to 0.2 microM for MTX. Induction of apoptosis by 2ME2 and MTX was observed in the tested cells. 2ME2 was a G2/M-phase specific blocker whereas MTX was an S-phase specific blocker in cell cycle analyses. At 1 microM concentration, 2ME2 and MTX showed similar anti-proliferative effect on the lymphoma cell lines. In previously reported studies, for normal endothelial cells, 1 microM 2ME2 showed no appreciable toxicity, while MTX at this same concentration exhibited significant cytotoxicity. 2ME2 at a therapeutic target concentration of 1 mu M may be an effective and relatively non-toxic drug for the treatment of PCNSL with IOL.

CONCLUSIONS

Our study of the effect of 2ME2 and MTX on anti-proliferation, apoptosis, and cell cycling suggests that 2ME2 is a potential agent for treating PCNSL and IOL.

The distinction between lesional and non-lesional skin in psoriasis vulgaris through expression of adhesion molecules ICAM-1 and VCAM-1

Psoriasis vulgaris [pv] is a systemic inflammatory skin disease affecting 2-4% population. It is well known that pv affects some parts of the skin and also whole skin as in erythrodermic form. We still do not know why in pv some parts of the skin are affected and others are not. In our hypothesis we assumed that the whole skin is in <<stand by>> position and non-lesional skin could become in every moment lesional. According to our hypothesis and also other author's research, high expression of adhesion molecules ICAM-1 and VCAM-1 in lesional as well as non-lesional skin in pv, supports this hypothesis, suggesting a significance of these molecules in pathogenesis of pv. Our hypothesis could be proved by immunohistochemical stain of ICAM-1 and VCAM-1 in lesional and non-lesional skin of pv patient in comparison with healthy skin.

Revisiting the immunomodulators tacrolimus, methotrexate, and mycophenolate mofetil: their mechanisms of action and role in the treatment of IBD

Inflammatory bowel diseases (IBDs) are thought to result from unopposed immune responses to normal gut flora in a genetically susceptible host. A variety of immunomodulating therapies are applied for the treatment of patients with IBDs. The first-line treatment for IBDs consists of 5-aminosalicylate and/or budesonide. However, these first-line therapies are often not suitable for continuous treatment or do not suffice for the treatment of severe IBD. Recently, efforts have been made to generate novel selective drugs that are more effective and have fewer side effects. Despite promising results, most of these novel drugs are still in a developmental stage and unavailable for clinical application. Yet, another class of established immunomodulators exists that is successful in the treatment of inflammatory bowel diseases. While waiting for emerging novel therapies, the use of these more established drugs should be considered. Furthermore, one of the advantages of using established immunomodulators is the well-documented knowledge on the long-term side effects and on the mechanisms of action. In this review, the authors discuss 3 well-known immunomodulators that are being applied with increased frequency for the treatment of IBD: tacrolimus, methotrexate, and mycophenolate mofetil. These agents have been used for many years as treatment modalities for immunosuppression after organ transplantation, for the treatment of cancer, and for immunomodulation in several other immune-mediated diseases. First, this review discusses the potential targets for immunomodulating therapies in IBDs. Second, the immunomodulating mechanisms and effects of the 3 immunomodulators are discussed in relationship to these treatment targets.

Increased Neutrophil Adherence in Psoriasis: Role of the Human Endothelial Cell Receptor Thy-1 (CD90)

The chronic inflammatory skin disease psoriasis is characterized by prominent skin infiltration by neutrophils and microabscess formation. The adhesion of leukocytes and subsequent transmigration through the activated endothelium is one prerequisite for the accumulation of these cells in skin. In recent studies, the human Thy-1 (CD90) was characterized as an adhesion molecule on activated endothelial cells (ECs) mediating the adhesion of neutrophils via the interaction with the beta2-integrin Mac-1. Based on these novel findings, we compared the roles of Thy-1 and ICAM-1 in the adhesion of neutrophils from patients with psoriasis to activated ECs. The adhesion of peripheral blood neutrophils of patients suffering from psoriasis to Thy-1-transfected cells as well as to activated, Thy-1-expressing human dermal microvascular ECs (HDMECs) is distinctly increased in comparison to the adhesion of neutrophils from healthy controls. In contrast, adherence of psoriatic neutrophils to ICAM-1 transfectants is, if at all, only slightly enhanced compared to healthy controls. The interaction of healthy as well as psoriatic polymorphonuclear cells to Thy-1 transfectants and HDMECs was significantly inhibited by blocking Thy-1 on ECs or its receptor Mac-1 on neutrophils, indicating the importance of this interaction for the adhesion of neutrophils to activated endothelium. In conclusion, our data indicate that the adhesion of neutrophils to activated ECs mediated by Thy-1/Mac-1 interaction is an important attachment mechanism facilitating their subsequent migration into lesional psoriatic skin.

The changes in expression of ICAM-3, Ki-67, PCNA, and CD31 in psoriatic lesions before and after methotrexate treatment

Although the effectiveness of methotrexate (MTX) in the treatment of psoriasis is very well established, the mechanism of action is poorly understood. It was suggested that the therapeutic effect of MTX in psoriasis might be mediated by inhibition of adhesion molecule expression. The aim of our study was to investigate the different effects of MTX treatment on cell proliferation, inflammatory infiltrate, adhesion molecules, and angiogenesis in psoriasis, and to clarify the mechanism by which MTX exerts its therapeutic effects. Clinical response, the morpho-phenotypic changes, epidermal thickness, and mitosis count were analyzed and the expression of CD31 and ICAM-3, proliferative markers such as Ki-67, PCNA, were evaluated by immunohistochemical techniques in lesional psoriatic epidermis, before and after the treatment with MTX in ten patients. In posttreatment biopsies a decrease in the degree of epidermal hyperplasia and a significant reduction in the severity of the inflammatory infiltrate (P<0.05) were observed. In addition, CD31 and ICAM-3 expression was significantly decreased on dermal cellular infiltrate, (respectively; P<0.05, P<0.01). Ki67 and PCNA expression were suppressed concurrently in about 90% of cases (P<0.01). We suggest that MTX may have an inhibitory effect on an initial integral component of the pathways that lead to psoriasis. Immunopharmacologic intervention in adhesion event has the potential to improve psoriasis. Inhibition of revascularization may be another mechanism of action of MTX.

The anti-inflammatory action of methotrexate is not mediated by lymphocyte apoptosis, but by the suppression of activation and adhesion molecules

Low-dose methotrexate (MTX) is an established and highly effective treatment for severe psoriasis and rheumatoid arthritis; however, its mechanism of action remains unclear. We investigated the effects of low-dose MTX on antigen-stimulated peripheral blood mononuclear cells and explored through which cellular pathways these effects are mediated. We show that MTX caused a dose-dependent suppression of T cell activation and adhesion molecule expression, and this was not due to lymphocyte apoptosis. The suppression of intercellular adhesion molecule (ICAM)-1 was adenosine and folate-dependent, while MTX suppression of the skin-homing cutaneous lymphocyte-associated antigen (CLA) was adenosine-independent. The effect of MTX on CLA, but not ICAM-1, required the constant presence of MTX in cultures. Thus, the suppression of T cell activation and T cell adhesion molecule expression, rather than apoptosis, mediated in part by adenosine or polyglutamated MTX or both, are important mechanisms in the anti-inflammatory action of MTX.

Methotrexate markedly reduces the expression of vascular E-selectin, cutaneous lymphocyte-associated antigen and the numbers of mononuclear leucocytes in psoriatic skin

A positive correlation between disease severity and the frequency of cutaneous lymphocyte-associated antigen (CLA)-positive T cells in the blood of untreated patients with psoriasis has been previously observed. A dose-dependent inverse relationship between disease severity and the frequency of circulating CLA(+) T cells in psoriasis patients on methotrexate (MTX) treatment is reported. Circulating T cells from a patient with psoriasis were monitored for CLA expression on a daily basis for 5 weeks. A decrease in the intensity and frequency of CLA(+) mononuclear leucocytes was consistently observed in the blood during the first 3-4 days after each MTX intake, but the CLA expression increased thereafter until the next weekly dose was taken. The MTX treatment of this patient was then discontinued for 16 days, and a marked subjective exacerbation was reported within 9 days, which was confirmed objectively (laser Doppler perfusion imaging) after 11 and 16 days. Biopsies taken 4 days after the last MTX intake showed only a few mononuclear leucocytes in lesional skin, but the exacerbation coincided with a marked increase in CLA expression by mononuclear blood leucocytes, followed by an increase in endothelial E-selectin and a striking influx of CLA(+) mononuclear cells into lesional skin. Conversely, a clinical improvement after the patient resumed the MTX treatment was associated with reduction in CLA expression by mononuclear cells in the blood, downregulation of endothelial E-selectin and an approximate threefold decrease in mononuclear leucocyte infiltration of lesional skin. No MTX-associated changes were detected in the expression of very late antigen-4, vascular cell-adhesion molecule-1 nor the late activation marker CD25. It is concluded that MTX decreases the expression of CLA and E-selectin and that this may be a major mechanism for the therapeutic effect of MTX on psoriatic skin lesions.