Increased levels of plasma endothelin-1 in patients with psoriasis

Tumor Necrosis Factor (TNF) α, Endothelin (ET) 1 and α1-Acid Glycoprotein (AGP) as Potential Urine and Serum Markers of Metabolic Complications in Psoriasis?

INTRODUCTION

Psoriasis, one of the most frequent dermatoses, strongly associated with metabolic disorders which increase patients' comorbidity and mortality. Hence, it is essential to look for markers of such complications. Our aim was to assess the clinical utility of urinary tumor necrosis factor alpha (TNFα), endothelin 1 (ET-1) and α1-acid glycoprotein (α1AGP) as well as their serum concentrations as markers of metabolic complications in psoriatics, and to examine the relations of these markers to clinical and demographic parameters.

METHODS

The study involved 60 patients with plaque psoriasis and 30 volunteers without skin diseases (the control group). Serum and urinary concentrations of TNFα, ET-1 and α1AGP were measured by ELISA. Psoriasis severity was assessed using the psoriasis activity and severity index (PASI). Routine laboratory investigations were additionally performed.

RESULTS

All serum markers were significantly higher in the patients compared to the controls. TNFα was undetectable in the urine in half of the patients. The urinary ET-1/creatinine concentration ratio was significantly lower in the psoriatics than the controls, whereas the absolute urinary α1AGP was significantly higher and the α1AGP/creatinine ratio was insignificantly different. There was no correlation between serum or urinary markers and PASI. All serum markers were higher in patients with psoriasis lasting less than 15 years.

CONCLUSIONS

Serum TNFα, ET-1 and α1AGP seem to be useful biomarkers of metabolic syndrome in psoriatics. ET-1 could perhaps become a urinary marker of metabolic disorders in psoriatics, but further studies are required to confirm that a decreased ET-1 concentration in urine is a reliable predictive tool. Increased urinary α1AGP also requires more in-depth research as a potential marker. TNFα urine assessment does not seem to be useful for screening for metabolic disorders in psoriatics. Serum or urinary TNFα, ET-1 and α1AGP do not seem to be associated with psoriasis severity or duration.

Basic mechanisms of itch

Pruritus (or itch) is an unpleasant sensation leading to a desire to scratch. In the epidermis, there are selective C or Aδ epidermal nerve endings that are pruriceptors. At their other ends, peripheral neurons form synapses with spinal neurons and interneurons. Many areas in the central nervous system are involved in itch processing. Although itch does not occur solely because of parasitic, allergic, or immunologic diseases, it is usually the consequence of neuroimmune interactions. Histamine is involved in a minority of itchy conditions, and many other mediators play a role: cytokines (eg, IL-4, IL-13, IL-31, IL-33, and thymic stromal lymphopoietin), neurotransmitters (eg, substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, neuropeptide Y, NBNP, endothelin 1, and gastrin-releasing peptide), and neurotrophins (eg, nerve growth factor and brain-derived neurotrophic factor). Moreover, ion channels such as voltage-gated sodium channels, transient receptor potential vanilloid 1, transient receptor ankyrin, and transient receptor potential cation channel subfamily M (melastatin) member 8 play a crucial role. The main markers of nonhistaminergic pruriceptors are PAR-2 and MrgprX2. A notable phenomenon is the sensitization to pruritus, in which regardless of the initial cause of pruritus, there is an increased responsiveness of peripheral and central pruriceptive neurons to their normal or subthreshold afferent input in the context of chronic itch.

The Nax (SCN7A) channel: an atypical regulator of tissue homeostasis and disease

Within an articulately characterized family of ion channels, the voltage-gated sodium channels, exists a black sheep, SCN7A (Nax). Nax, in contrast to members of its molecular family, has lost its voltage-gated character and instead rapidly evolved a new function as a concentration-dependent sensor of extracellular sodium ions and subsequent signal transducer. As it deviates fundamentally in function from the rest of its family, and since the bulk of the impressive body of literature elucidating the pathology and biochemistry of voltage-gated sodium channels has been performed in nervous tissue, reports of Nax expression and function have been sparse. Here, we investigate available reports surrounding expression and potential roles for Nax activity outside of nervous tissue. With these studies as justification, we propose that Nax likely acts as an early sensor that detects loss of tissue homeostasis through the pathological accumulation of extracellular sodium and/or through endothelin signaling. Sensation of homeostatic aberration via Nax then proceeds to induce pathological tissue phenotypes via promotion of pro-inflammatory and pro-fibrotic responses, induced through direct regulation of gene expression or through the generation of secondary signaling molecules, such as lactate, that can operate in an autocrine or paracrine fashion. We hope that our synthesis of much of the literature investigating this understudied protein will inspire more research into Nax not simply as a biochemical oddity, but also as a potential pathophysiological regulator and therapeutic target.

RNA-seq and flow-cytometry of conventional, scalp, and palmoplantar psoriasis reveal shared and distinct molecular pathways

It has long been recognized that anatomic location is an important feature for defining distinct subtypes of plaque psoriasis. However, little is known about the molecular differences between scalp, palmoplantar, and conventional plaque psoriasis. To investigate the molecular heterogeneity of these psoriasis subtypes, we performed RNA-seq and flow cytometry on skin samples from individuals with scalp, palmoplantar, and conventional plaque psoriasis, along with samples from healthy control patients. We performed differential expression analysis and network analysis using weighted gene coexpression network analysis (WGCNA). Our analysis revealed a core set of 763 differentially expressed genes common to all sub-types of psoriasis. In contrast, we identified 605, 632, and 262 genes uniquely differentially expressed in conventional, scalp, and palmoplantar psoriasis, respectively. WGCNA and pathway analysis revealed biological processes for the core genes as well as subtype-specific genes. Flow cytometry analysis revealed a shared increase in the percentage of CD4+ T regulatory cells in all psoriasis subtypes relative to controls, whereas distinct psoriasis subtypes displayed differences in IL-17A, IFN-gamma, and IL-22 production. This work reveals the molecular heterogeneity of plaque psoriasis and identifies subtype-specific signaling pathways that will aid in the development of therapy that is appropriate for each subtype of plaque psoriasis.

Endothelial dysfunction and its treatment in psoriasis patients

Goal. To assess the effect of a combined cytostatic therapy and sulodexide on the functional condition of the vascular endothelium in psoriatic patients. Materials and methods. The authors examined 74 patients suffering from psoriasis vulgaris and exudative form of psoriasis. Depending on the treatment option, the patients were subdivided into two groups: Group I (n = 41) receiving a cytostatic therapy and Group II where patients received sulodexide as well. The severity of the endothelium dysfunction was assessed based on laboratory assessments such as nitrogen oxide and endothelin 1 in the blood serum. Results. Prior to the treatment, the level of nitrogen oxide was reduced and endothelin 1 was increased in the blood serum of most patients. Substantial improvement of the pathological process was observed in patients from Group I after the cytostatic therapy (total dose of methotrexate: 100 mg); no normalization of laboratory assessments was observed. In patients from Group II receiving methotrexate (total dose: 40 mg) along with sulodexide, improvement or recovery was observed after the completion of the treatment; endothelium dysfunction was normalized. Conclusion. The inclusion of sulodexide in a complex therapy normalizes endothelial dysfunction in case of psoriasis and reduces the dose and duration of methotrexate treatment.

The angiotensin-converting enzyme insertion/deletion and the endothelin -134 3A/4A gene polymorphisms in patients with chronic plaque psoriasis

BACKGROUND

Psoriasis is a common chronic inflammatory skin disease. Vasoactive peptides such as endothelin-1 (ET-1) and bradykinin have previously been implicated in the pathogenesis of chronic plaque psoriasis. The angiotensin-converting enzyme (ACE) gene carries a 287-base pair insertion/deletion (I/D) gene polymorphism, which is associated with plasma concentrations of bradykinin-degrading ACE. A functional polymorphism (EDN1 -134 3A/4A) in the gene encoding ET-1 has been shown to affect ET-1 expression. The purpose of the present study was thus to investigate a hypothesized association between these gene polymorphisms and the presence of chronic plaque psoriasis.

METHODS

The present case-control study comprised 207 patients with chronic plaque psoriasis (136 with early onset and 71 with late onset disease) and 182 control subjects. Genotypes of EDN1 and ACE were determined by a 5' exonuclease assay (Taqman).

RESULTS

The prevalence of the homozygous ACE II genotype was significantly higher in patients with early-onset psoriasis than among control subjects (30.9% vs 19.2%, P = 0.016), yielding an odds ratio of 1.88 [95% confidence interval (CI): 1.12-3.15] for early-onset disease. For late-onset psoriasis, presence of the ACE II genotype was associated with a non-significant odds ratio 1.54 (95% CI: 0.81-2.92). As for the EDN1 -134 3A/4A gene polymorphism, no significant differences in genotype distributions were found between patients with either early- or late-onset psoriasis and control subjects (EDN1 -134 4A/4A: 9.6% in early-onset and 5.6% late-onset psoriasis vs 7.7% in controls; P > 0.05).

CONCLUSIONS

Our data suggest that homozygosity for the ACE I allele may affect susceptibility to early-onset psoriasis.