Circulating level of chemerin is upregulated in psoriasis

The mind-skin connection: A narrative review exploring the link between inflammatory skin diseases and psychological stress

Inflammatory skin diseases are known to negatively impact patient psychology, with individuals experiencing higher rates of stress and subsequent diminished quality of life, as well as mental health issues including anxiety and depression. Moreover, increased psychological stress has been found to exacerbate existing inflammatory skin diseases. The association between inflammatory skin diseases and psychological stress is a timely topic, and a framework to better understand the relationship between the two that integrates available literature is needed. In this narrative review article, we discuss potential neurobiological mechanisms behind psychological stress due to inflammatory skin diseases, focusing mainly on proinflammatory cytokines in the circulating system (the brain-gut-skin communications) and the default mode network in the brain. We also discuss potential descending pathways from the brain that lead to aggravation of inflammatory skin diseases due to psychological stress, including the central and peripheral hypothalamic-pituitary-adrenal axes, peripheral nerves and the skin barrier function.

Chemerin - exploring a versatile adipokine

Chemerin is a small chemotactic protein and a key player in initiating the early immune response. As an adipokine, chemerin is also involved in energy homeostasis and the regulation of reproductive functions. Secreted as inactive prochemerin, it relies on proteolytic activation by serine proteases to exert biological activity. Chemerin binds to three distinct G protein-coupled receptors (GPCR), namely chemokine-like receptor 1 (CMKLR1, recently named chemerin₁), G protein-coupled receptor 1 (GPR1, recently named chemerin₂), and CC-motif chemokine receptor-like 2 (CCRL2). Only CMKLR1 displays conventional G protein signaling, while GPR1 only recruits arrestin in response to ligand stimulation, and no CCRL2-mediated signaling events have been described to date. However, GPR1 undergoes constitutive endocytosis, making this receptor perfectly adapted as decoy receptor. Here, we discuss expression pattern, activation, and receptor binding of chemerin. Moreover, we review the current literature regarding the involvement of chemerin in cancer and several obesity-related diseases, as well as recent developments in therapeutic targeting of the chemerin system.

The Skin-Liver Axis Modulates the Psoriasiform Phenotype and Involves Leucine-Rich α-2 Glycoprotein

Leucine-rich α-2 glycoprotein (LRG), one of the acute phase proteins mainly produced by the liver, similar to C-reactive protein, has been recognized as an inflammatory biomarker for rheumatoid arthritis and inflammatory bowel diseases. We recently demonstrated that LRG was also increased in the sera of psoriasis patients and correlated well with disease activity with a sensitivity and specificity much higher than C-reactive protein; however, whether LRG mechanistically contributed to the pathogenesis of psoriasis remained unclear. In this study, we explored the role of LRG in psoriasiform inflammation using LRG-knockout (KO) mice in an imiquimod (IMQ)-mediated model. Following topical treatment with IMQ, serum levels of LRG and its expression in the liver were abruptly elevated. Similarly, an acute surge of proinflammatory cytokines was observed in the liver, including IL-1β, TNF-α, and IL-6, although LRG-KO mice showed delayed responses. LRG-KO mice showed less skin inflammation in the IMQ model than wild-type mice. K5.Stat3C mice developed psoriasis-like lesions following tape stripping, which also abruptly induced LRG expression in the liver. A deficiency of Lrg mitigated tape stripping-induced lesions, similar to the IMQ model. These results indicate that LRG modulates both feed-forward and feedback loops of cytokines in the skin-liver axis involved with psoriasiform inflammation.

The complex role of adipokines in obesity, inflammation, and autoimmunity

The global obesity epidemic is a major contributor to chronic disease and disability in the world today. Since the discovery of leptin in 1994, a multitude of studies have characterized the pathological changes that occur within adipose tissue in the obese state. One significant change is the dysregulation of adipokine production. Adipokines are an indispensable link between metabolism and optimal immune system function; however, their dysregulation in obesity contributes to chronic low-grade inflammation and disease pathology. Herein, I will highlight current knowledge on adipokine structure and physiological function, and focus on the known roles of these factors in the modulation of the immune response. I will also discuss adipokines in rheumatic and autoimmune diseases.

Chemerin Added to Endothelin-1 Promotes Rat Pulmonary Artery Smooth Muscle Cell Proliferation and Migration

Background

While chemerin has been shown to increase proliferation and migration of systemic vascular smooth muscle cells (SMCs) contributing therefore to the development of hypertension, this remains to be clarified for the pulmonary circulation.

Methods

Expression of chemerin and its three receptors (CMKRL1, CCRL2, GPR1) was examined by immunohistochemistry and RTq-PCR in lungs, pulmonary artery, and thoracic aorta from Wistar rats. Primary cultured rat pulmonary artery and thoracic aorta SMCs treated with recombinant chemerin (tested from 5.10^–9 to 10^–7 mol/L) were assessed for proliferation and migration (both with 10^–7 mol/L endothelin-1), as well as for staurosporine-induced apoptosis.

Results

In pulmonary artery and thoracic aorta, CMKLR1 expression was detected in both endothelial cells and SMCs. In primary cultured pulmonary artery SMCs, chemerin and its three receptors were expressed, and CMKLR1 expression was higher than those of CCRL2 and GPR1. Chemerin added to endothelin-1 increased pulmonary artery SMC proliferation, while chemerin or endothelin-1 alone did not. This effect was less pronounced in thoracic aorta SMCs. Chemerin induced pulmonary artery and thoracic aorta SMC migration, which was exacerbated by endothelin-1 and more pronounced in thoracic aorta SMCs. Chemerin concentration-dependently reduced staurosporine-induced apoptosis in both pulmonary artery and thoracic aorta SMCs. In pulmonary artery SMCs, endothelin-1 treatment increased the expression of CMKLR1, CCRL2, and GPR1, while these expressions were not altered in thoracic aorta SMCs.

Conclusion

Chemerin/CMKRL1 signaling, in conjunction with a key mediator in the pathogenesis of pulmonary hypertensive diseases, endothelin-1, stimulated proliferation and migration, and increased resistance to apoptosis in rat primary cultured pulmonary artery SMCs. Our results suggest that this signaling could play a role in pulmonary artery remodeling observed in pulmonary hypertension.

Analysis of serum chemerin concentrations in psoriatic patients in relation to metabolic abnormalities

Introduction

Recent data depict psoriasis as a systemic disease with many comorbidities, especially metabolic syndrome and cardiovascular diseases. Chemerin, an adipokine secreted by adipose tissue cells, may prove to be an important link between psoriasis and its comorbidities.

Aim

Assessment of serum concentrations of chemerin in patients with psoriasis and the healthy control group as well as evaluation of a possible correlation between adipokine concentrations and selected psoriasis severity indices and metabolic syndrome components.

Material and methods

One hundred and two patients with diagnosed psoriasis and 40 healthy volunteers were enrolled in the study. In all subjects, serum chemerin concentrations and selected metabolic syndrome components including lipid and glucose levels were determined. Psoriasis severity was assessed using the PASI and BSA indices.

Results

A higher concentration of chemerin was demonstrated in the group of psoriasis patients compared to the control group (p < 0.05). A positive correlation between chemerin concentration and C-reactive protein concentration (p = 0.001), body mass index (p = 0.031) and triglyceride concentration (p = 0.043) was found. An inverse correlation with high-density lipoprotein cholesterol concentrations (p = 0.015) was also noted. Significantly higher concentrations of chemerin were observed in psoriatic patients with elevated low-density lipoptotein (LDL) cholesterol levels in comparison with patients with normal LDL values (p = 0.032). Chemerin concentrations were also significantly higher in patients with both psoriasis and elevated glucose levels compared to patients with normal blood glucose values (p = 0.043).

Conclusions

The results obtained suggest a possible role of chemerin as an adipokine linking psoriasis with metabolic syndrome.

Chemerin/ChemR23 axis triggers an inflammatory response in keratinocytes through ROS-sirt1-NF-κB signaling

Psoriasis is a chronic disease which carries the emotional and social burden, promotes joint disability and raises comorbidity possibility in patients. Obesity is closely correlated with the occurrence of psoriasis and adipokines produced by adipose tissues were found to be critical culprits. Chemerin is one of them and its expression was increased in patients with psoriatic arthritis. In our hypothesis, chemerin might act on keratinocytes and promote an inflammatory response, which plays an essential role in psoriatic epidermis. To validate our hypothesis, HaCaT cells and primary human keratinocytes were treated with chemerin (5, 10, and 20 ng/mL for 24 hours). Enzyme-linked immunosorbent assay (ELISA) was used to determine the secretion of inflammatory factors. Nuclear factor-κB (NF-κB) activation and p65 acetylation were evaluated by Western blot analysis. The expression and activity of sirtuin 1 (sirt1), a deacetylase act on p65, were also analyzed. The results showed that chemerin prompted inflammatory factors secretion, NF-κB activation and p65 acetylation through chemerin receptor 23 receptor. Chemerin constrained the expression and deacetylase activity of sirt1 through augment of reactive oxygen species (ROS) production. Additionally, chemerin exacerbated psoriasiform dermatitis in imiquimod-treated mice model. In conclusion, chemerin can seduce inflammatory response and promote NF-κB activation through inhibition of sirt1 activity by ROS production.

Neutrophilic granulocytes – promiscuous accelerators of atherosclerosis

Neutrophils, as part of the innate immune system, are classically described to be main actors during the onset of inflammation enforcing rapid neutralisation and clearance of pathogens. Besides their wellstudied role in acute inflammatory processes, recent advances strongly indicate a so far underappreciated importance of neutrophils in initiation and development of atherosclerosis. This review focuses on current findings on the role of neutrophils in atherosclerosis. As pro-inflammatory mechanisms of neutrophils have primarily been studied in the microvascular environment; we here aim at translating these into the context of macrovascular inflammation in atherosclerosis. Since much of the pro-inflammatory activities of neutrophils stem from instructing neighbouring cell types, we highlight the promiscuous interplay between neutrophils and platelets, monocytes, T lymphocytes, and dendritic cells and its possible relevance to atherosclerosis.

Absence of the Non-Signalling Chemerin Receptor CCRL2 Exacerbates Acute Inflammatory Responses In Vivo

Chemerin is a chemotactic protein that induces migration of several immune cells including macrophages, immature dendritic cells, and NK cells. Chemerin binds to three G protein-coupled receptors (GPCRs), including CCRL2. The exact function of CCRL2 remains unclear. CCRL2 expression is rapidly upregulated during inflammation, but it lacks the intracellular DRYLAIV motif required for classical GPCR downstream signalling pathways, and it has not been reported to internalise chemerin upon binding. The aim of this study was to investigate what role if any CCRL2 plays during acute inflammation. Using the zymosan- and thioglycollate-induced murine models of acute inflammation, we report that mice deficient in the Ccrl2 gene display exaggerated local and systemic inflammatory responses, characterised by increased myeloid cell recruitment. This amplified myeloid cell recruitment was associated with increased chemerin and CXCL1 levels. Furthermore, we report that the inflammatory phenotype observed in these mice is dependent upon elevated levels of endogenous chemerin. Antibody neutralisation of chemerin activity in Ccrl2-/- mice abrogated the amplified inflammatory responses. Importantly, chemerin did not directly recruit myeloid cells but rather increased the production of other chemotactic proteins such as CXCL1. Administration of recombinant chemerin to wild-type mice before inflammatory challenge recapitulated the increased myeloid cell recruitment and inflammatory mediator production observed in Ccrl2-/- mice. We have demonstrated that the absence of CCRL2 results in increased levels of local and systemic chemerin levels and exacerbated inflammatory responses during acute inflammatory challenge. These results further highlight the importance of chemerin as a therapeutic target in inflammatory diseases.

Adipokines in psoriasis: An important link between skin inflammation and metabolic alterations

Psoriasis is a chronic inflammatory skin disease most common in Europe, North America, and Australia. The etiology and pathomechanisms underlying the evolution and persistence of the skin alterations are increasingly being understood and have led to the development of effective anti-psoriatic therapies. Apart from the skin manifestations, psoriasis is associated with the metabolic syndrome (MetS), known to increase the risk of type 2 diabetes mellitus and cardiovascular disorders. Research of the last years demonstrated a dysregulated adipokine balance as an important link between inflammation, MetS, and consequential disorders. This article describes selected adipokines and their potential role in both metabolic comorbidity and skin inflammation in psoriasis.

The triad psoriasis-obesity-adipokine profile

Psoriasis is a chronic inflammatory skin disease, often associated with overweight/obesity. The adipose tissue is a complex organ that secretes several adipokines, involved in the regulation of some metabolic processes, such as lipid metabolism, glucose homeostasis, angiogenesis, blood pressure and inflammation. In obesity, the distribution and function of adipose tissue, and the adipokine profile are altered. The unbalanced production of pro- and anti-inflammatory adipokines in obesity, contributes to the development of a chronic low-grade inflammation state, which seems to favour worsening of psoriasis lesion and a poorer response to treatment. In this review, we will debate published data concerning the current knowledge about the triad psoriasis-obesity-adipokine profile.

Chemerin: A comprehensive review elucidating the need for cardiovascular research

When chemerin was discovered in 1997, it was relegated to being a protein associated with the normal skin function contrasting the setting of psoriasis. However, with the discovery of multiple receptors for the chemerin protein and a vast collection of associations with various pathologies, chemerin has global influence capable of regulating chemotactic, adipokine, autocrine/paracrine, adipogenic, angiogenic, and reproductive functions. These individual abilities of chemerin are important for understanding its basic pharmacology and physiology, but application of these principles to human pathology relies on the ability of scientists and physicians to view this protein from a much wider, all-encompassing angle. A global participant in the action of chemerin is the cardiovascular system (CVS). Although the CVS may not have as many direct interactions (e.g. smooth muscle in endothelium) with chemerin as it does indirect (e.g. chemerin activation in the lumen by proteases), our basic understanding of the CVS and its relation to chemerin is necessary to form a proper grasp of its individual actions and make the applications to pathology. This review provides a fundamental, yet comprehensive review of chemerin that inherently identifies the CVS as a necessary link between chemerin and its associated pathologies, but also calls for basic cardiovascular research as the solution to this chasm between knowledge and application.

Effect of psoriasis activity on serum adiponectin and leptin levels

INTRODUCTION

Psoriasis is an inflammatory and chronic skin disease associated with obesity, cardiovascular diseases, diabetes and metabolic syndrome. Adipokines, as bioactive substances secreted from adipose tissue, are involved in various metabolic diseases.

AIM

To investigate the association between psoriasis severity and serum adiponectin and leptin levels in patients with psoriasis.

MATERIAL AND METHODS

Serum fasting adiponectin and leptin levels were examined by an enzyme-linked immunosorbent assay in 49 patients with relapse of plaque-type psoriasis and 16 healthy controls. The results were correlated with the Psoriasis Area and Severity Index (PASI), body mass index (BMI), several inflammatory markers, duration of the disease and present relapse.

RESULTS

Serum adiponectin and leptin levels were significantly decreased in psoriatic patients in comparison to the control group. There were no correlations between the above measures and PASI scores, patients' age, duration of the disease, present relapse and hospitalization, neither between white blood cells or platelets counts. Serum adiponectin levels significantly correlated with C-reactive protein (CRP) levels. Adiponectin was negatively and leptin positively correlated to BMI at statistical significance. Multivariate analysis demonstrated a significant positive correlation between adiponectin and CRP or PASI concentrations as well as between BMI and leptin concentration.

CONCLUSIONS

The data showed that serum adiponectin levels increase and serum leptin levels decrease with psoriasis severity. Leptin might be useful in assessing severity and the risk of complications of psoriasis. Moreover, these results confirmed the relationship between leptin, obesity and psoriasis.

Assessment of Leptin Gene Polymorphism rs2060713 in Psoriasis Vulgaris

Psoriasis is a lifelong disorder characterized by approximately 8-fold reduction of the duration of normal skin keratinocyte cell cycle and 2-fold increase of the number of dividing cells. Multiple genes, several environmental factors, and immune system alterations are involved in the pathogenesis of psoriasis. Hyperleptinemia is associated with psoriasis and leptin acts as an angiogenic factor. Angiogenetic processes precede the epidermal hyperplasia in psoriasis, indicating possible involvement of leptin in the pathogenesis of psoriasis. Leptin gene polymorphisms and their association with psoriasis have been given very little attention. We present a study of the rs2060713C/T genetic polymorphism in the pathogenesis of psoriasis vulgaris in 263 vulgaris patients and 252 unrelated matched healthy controls. No statistically significant differences were observed between patients and controls. A statistically nonsignificant trend was observed in males with the early onset type of psoriasis (11.1% C/T in patients versus 5.6% in controls) and in females with the late onset type of the disease (12.8% C/T in patients versus 3.3% in controls). Still, there is no hard evidence on correlation of psoriasis vulgaris with this polymorphism. Possible association with specific forms of the disease and either gender needs further investigation in larger studies.

Leptin levels in patients with psoriasis: a meta-analysis

BACKGROUND

There have been inconsistent results reported for leptin levels in patients with psoriasis.

AIM

To evaluate leptin levels in patients with psoriasis using a meta-analysis of studies comparing leptin levels in controls and in patients with psoriasis.

METHODS

PubMed (MEDLINE), EMBASE and the Cochrane Library were searched for relevant papers published in English. Pooled weighted mean differences (WMDs) and 95% CIs were calculated using random-effects and fixed-effects models. Heterogeneity between studies was assessed using the Cochran Q and I(2) statistics.

RESULTS

In total, 11 studies, comprising 773 patients with psoriasis and 570 healthy controls, were identified. Leptin levels were significantly higher in patients with psoriasis compared with controls (WMD = 7.24, 95% CI 4.55-9.93; P < 0.001). On stratified analysis, significant differences in leptin levels between patients with psoriasis and controls were reported only in serum samples (P < 0.001), and not in plasma samples (P = 0.025). Sensitivity analysis showed that there were no changes in the direction of effect when any one study was excluded. No publication bias was detected.

CONCLUSIONS

Leptin levels are higher in patients with psoriasis compared with those in controls. Future studies are warranted to clarify the association between leptin levels and the pathomechanism of psoriasis.

Proteolytic activation of prochemerin by kallikrein 7 breaks an ionic linkage and results in C-terminal rearrangement

The excessive accumulation of adipose tissue in obesity is associated with multiple inflammatory dermatological diseases. Chemerin, a chemoattractant adipokine, dependent on proteolytical activation, is highly expressed in skin. Different proteases have been reported to activate prochemerin, but none is inherently expressed in human skin. In the present study, we identified a tissue-specific protease and investigated the underlying mechanism of activation at the molecular level. We characterized human KLK7 (kallikrein 7) as a prochemerin processing protease in vitro converting prochemerin into active chemerinF(156). The activating truncation by the protease might trigger a structural rearrangement leading to an increased affinity of chemerin to CMKLR1 (chemokine-like receptor 1). Molecular modelling and experimental data suggest an underlying ionic interaction in prochemerin C-terminal domains. These findings provide a general molecular basis for the necessity of C-terminal processing of prochemerin. Moreover, immunohistochemistry was used to investigate prochemerin, KLK7 and the recently identified KLK7 inhibitor vaspin expression in human skin biopsies, and distinct co-localization in psoriatic biopsies was observed. On the basis of these results, it is hypothesized that KLK7 activity may contribute to the development of psoriatic lesions as a consequence of excessive chemerin activation and impaired protease activity regulation by vaspin. Therefore this interaction represents an interesting target for psoriasis therapy and treatment of other obesity-related diseases.

Towards an integrative approach to understanding the role of chemerin in human health and disease

Chemerin is an adipocyte-secreted protein with autocrine/paracrine roles on adipose development and function as well as endocrine roles in metabolism and immunity. Following prochemerin secretion, protease-mediated generation of chemerin isoforms with a range of biological activities is a key regulatory mechanism controlling local, context-specific chemerin bioactivity. Together, experimental and clinical data indicate that localized and/or circulating chemerin expression and activation are elevated in numerous metabolic and inflammatory diseases including psoriasis, obesity, type 2 diabetes, metabolic syndrome and cardiovascular disease. These elevations are positively correlated with deleterious changes in glucose, lipid, and cytokine homeostasis, and may serve as a link between obesity, inflammation and other metabolic disorders. This review highlights the current state of knowledge regarding chemerin expression, processing, biological function and relevance to human disease, particularly with respect to adipose tissue development, inflammation, glucose homeostasis and cardiovascular disease. Furthermore, it discusses study variability, deficiencies in current measurement, and questions concerning chemerin function in disease, with a special emphasis on techniques and tools used to properly assess chemerin biology. An integration of basic and clinical research is key to understanding how chemerin influences disease pathobiology, and whether modulation of chemerin levels and/or activity may serve as a potential method to prevent and treat metabolic diseases.

Serum chemerin is increased in patients with chronic plaque psoriasis and normalizes following treatment with infliximab

BACKGROUND

Chronic plaque psoriasis is associated with obesity, which is a metabolic and inflammatory disorder. Adipokines are involved in the pathogenesis of psoriasis and they are biomarkers of obesity-related inflammation.

OBJECTIVES

To measure serum adipokines in patients with chronic plaque psoriasis treated with infliximab.

METHODS

Serum levels of chemerin, resistin, visfatin, C-reactive protein (CRP), lipids, glycaemia and liver enzymes were measured in 40 patients with psoriasis and 40 controls matched by age, sex and body mass index (BMI). Adipokines were measured at baseline and after 2-12 months of treatment with infliximab 5 mg kg(-1).

RESULTS

At baseline, levels of chemerin (195·9±48·5 vs. 145·6±27·1 ng mL(-1)), resistin (2·03±0·9 vs. 1·4±0·5 ng mL(-1)) and CRP (5·5±7·3 vs. 1·9 ±4·4 mg L(-1)) were higher (P<0·01) in patients with psoriasis compared with controls. Psoriasis was associated with elevated chemerin level independently of age, sex, BMI and levels of cholesterol and triglycerides. Chemerin was linearly correlated to CRP (r=0·4, P=0·01) and resistin (r=0·3, P=0·01). Chemerin levels were higher in patients affected by psoriatic arthritis than in patients with psoriasis without arthritis (195·5±49·1 vs. 158·1±37·5 ng mL(-1), P=0·01). After 2 months of infliximab treatment a significant reduction of chemerin, resistin and CRP levels was observed.

CONCLUSIONS

Patients with psoriasis have higher blood levels of adipokines, which normalize during therapy with infliximab. Whether this reduction is a direct effect of infliximab or secondary to a reduction of inflammation should be further investigated.

Clear association between serum levels of adipokines and T-helper 17-related cytokines in patients with psoriasis

BACKGROUND

Psoriasis represents one of the T-helper (Th)17-mediated autoimmune diseases, and has been shown to be associated with metabolic syndrome (MetS). It has been reported that some adipokines and Th17-related cytokines are altered in patients with psoriasis.

AIM

To examine the relationship between levels of adipokines and Th17-related cytokines in the serum of patients with psoriasis compared with healthy controls.

METHODS

We enrolled 30 patients with psoriasis and 30 normal controls in the study, and used ELISA to measure serum adipokines and Th17-related cytokines. The association between each adipokine and each cytokine was determined using Pearson correlation analysis. Multiple regression analysis using all adipokines and Th17-related cytokines as covariates was also performed.

RESULTS

Pearson correlation analysis showed a strong positive association between chemerin and resistin levels and between adiponectin and high molecular weight adiponectin in normal controls. By contrast, in patients with psoriasis, resistin levels were significantly positively associated with tumour necrosis factor-α, while there was a strong negative association between retinol binding protein-4 and interleukin (IL)-6 levels. Interestingly, a marked positive correlation between IL-22 and adiponectin was also found in patients with psoriasis. Leptin levels correlated positively with IL-6 in patients with psoriasis, but this did not reach significance. The correlations identified by the multiple regression analyses were almost identical to those from the Pearson analyses.

CONCLUSIONS

These data suggest that distinct interaction between adipokines and Th17 cytokines is involved in the pathogenesis of psoriasis.

Chemerin: a potential endocrine link between obesity and type 2 diabetes

Obesity and type 2 diabetes have reached epidemic levels and account for a substantial portion of the annual health expenditures of developed nations. While there is an abundance of epidemiological evidence demonstrating that obesity is a primary risk factor for developing type 2 diabetes, the mechanism(s) underlying this linkage are not completely understood. Given the enormous impact of these disorders on global health, considerable research effort has been devoted to elucidate the pathophysiological relationship between these two disorders. Two factors believed to contribute to the causal link between obesity and type 2 diabetes are chronic inflammation and altered secretion of adipose-derived signaling molecules (adipokines). Independent lines of investigation have implicated the novel adipokine chemerin as a regulator of adipogenesis, inflammation, and glucose metabolism through interactions with the cognate cell surface receptor chemokine-like receptor 1. Increased levels of chemerin that occur with obesity are hypothesized to be a causal factor in the development of type 2 diabetes as a consequence of dysregulation of the key physiological processes regulated by this adipokine. This review summarizes current research on the biological roles of chemerin and chemokine-like receptor 1, and highlights key questions to guide future research on the role of this adipokine in mediating obesity and the development of type 2 diabetes.

Kinetics of circulating Th17 cytokines and adipokines in psoriasis patients

Psoriasis is associated with an increase of Th17 cytokines, such as IL-17, IL-22, IL-21, and TNF-α, which are produced by Th17 cells. Adipokines are peptide hormones or cytokines secreted from adipose tissues and involved in the pathogenesis of metabolic syndrome (MS). Psoriasis patients have a high prevalence of the MS. In this study, we investigated the statistics of circulating Th17-related cytokines and adipokines in psoriasis patients. Our study identified the significant elevation of serum IL-6, IL-21, IL-22, and resistin levels in psoriasis patients. Increased serum levels of IL-22 and adiponectin were positively correlated with Psoriasis Area and Severity Index (PASI). In contrast, serum high molecular weight adiponectin levels were decreased in psoriasis and negatively correlated with PASI.