Increased serum chemerin concentration in patients with chronic pancreatitis

Circulating Biomarkers Involved in the Development of and Progression to Chronic Pancreatitis-A Literature Review

Chronic pancreatitis (CP) is the end-stage of continuous inflammation and fibrosis in the pancreas evolving from acute- to recurrent acute-, early, and, finally, end-stage CP. Currently, prevention is the only way to reduce disease burden. In this setting, early detection is of great importance. Due to the anatomy and risks associated with direct sampling from pancreatic tissue, most of our information on the human pancreas arises from circulating biomarkers thought to be involved in pancreatic pathophysiology or injury. The present review provides the status of circulating biomarkers involved in the development of and progression to CP.

Neutrophils regulate tumor angiogenesis in oral squamous cell carcinoma and the role of Chemerin

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity. Tumor angiogenesis plays a crucial role in tumor progression. Studies have established the correlation between neutrophils and tumor angiogenesis in the tumor microenvironment. A previous study found that overexpression of Chemerin- in OSCC increased the infiltration of neutrophils in tumor tissues. This study aims to investigate the mechanisms underlying the regulation of the development and progression of OSCC, which have great significance in enhancing the postoperative survival of patients with OSCC. This study evaluated the accuracy of neutrophil count combined with MVD in predicting patients' survival time and its relationship with clinicopathological parameters and prognosis. Additionally, the study explored the effects of the Chemerin-neutrophil interaction on the angiogenic function of HUVECs. In OSCC, the overexpression of Chemerin promoted the angiogenesis of HUVECs through neutrophils. Moreover, Chemerin upregulated pro-angiogenic factors (e.g., VEGF-A, MMP-9, MMP-2, and S100A9) in neutrophils by activating MEK/ERK signaling pathway. In vivo experiments demonstrated that Chemerin may promote tumor growth by regulating tumor angiogenesis. In conclusion, the results suggest that neutrophil count and MVD serve as poor prognostic factors for patients with OSCC, and their combination is a more effective factor in predicting the survival time of OSCC patients. Neutrophils potentially contribute to angiogenesis through MEK/ERK signaling pathway via Chemerin and participate in the progression and metastasis of OSCC.

The Role of Chemerin in Metabolic and Cardiovascular Disease: A Literature Review of Its Physiology and Pathology from a Nutritional Perspective

Chemerin is a novel adipokine that plays a major role in adipogenesis and lipid metabolism. It also induces inflammation and affects insulin signaling, steroidogenesis and thermogenesis. Consequently, it likely contributes to a variety of metabolic and cardiovascular diseases, including atherosclerosis, diabetes, hypertension and pre-eclampsia. This review describes its origin and receptors, as well as its role in various diseases, and subsequently summarizes how nutrition affects its levels. It concludes that vitamin A, fat, glucose and alcohol generally upregulate chemerin, while omega-3, salt and vitamin D suppress it. Dietary measures rather than drugs acting as chemerin receptor antagonists might become a novel tool to suppress chemerin effects, thereby potentially improving the aforementioned diseases. However, more detailed studies are required to fully understand chemerin regulation.

Plasma Chemerin Is Induced in Critically Ill Patients with Gram-Positive Infections

Chemerin is a chemoattractant protein abundantly expressed in hepatocytes. Chemerin exerts pro- and anti-inflammatory effects and acts as a pro-resolving protein. Chemerin levels are low in patients with liver cirrhosis and are increased in sepsis. The aim of this study was to identify associations between plasma chemerin levels and underlying diseases as well as causes of severe illness. The cohort included 32 patients with liver cirrhosis who had low systemic chemerin, and who were not considered for further evaluation. Plasma chemerin levels were similar between the 27 patients with systemic inflammatory response syndrome (SIRS), the 34 patients with sepsis and the 63 patients with septic shock. Chemerin in plasma correlated with C-reactive protein and leukocyte count but not with procalcitonin, a clinical marker of bacterial infection. Plasma chemerin did not differ among patients with and without ventilation and patients with and without dialysis. Vasopressor therapy was not associated with altered plasma chemerin levels. Infection with severe acute respiratory syndrome coronavirus 2 had no effect on plasma chemerin levels. Baseline levels of plasma chemerin could not discriminate between survivors and non-survivors. Notably, Gram-positive infection was associated with higher chemerin levels. In summary, the current study suggests that plasma chemerin might serve as an early biomarker for the diagnosis of Gram-positive infections in patients with sepsis.

The Association between Serum Chemerin and Peritoneal Membrane Transport Function in Patients Undergoing Incident Peritoneal Dialysis: A Prospective Cohort Study

INTRODUCTION

Some biomarkers in drained dialyzate or peritoneal membrane have been found related to the dialyzate/plasma ratio of creatinine at 4 h (D/P Cr) in patients undergoing peritoneal dialysis (PD). But so far, there is no report on serum markers. Some biomarkers are associated with cardiovascular diseases (CVDs). Chemerin is a multifunctional chemoattractant adipokine which plays important roles in inflammation, adipogenesis, and metabolism. We intended to investigate the role of chemerin in the peritoneal membrane transport function and CVDs in incident PD patients.

METHODS

This prospective cohort study was conducted in our PD center. The patients underwent initial standardized peritoneal equilibration test after PD for 4-6 weeks. Level of serum chemerin was determined via enzyme-linked immunosorbent assay. The patients' CVDs were recorded during the follow-up period.

RESULTS

151 eligible patients with a mean age of 46.59 ± 13.52 years were enrolled, and the median duration of PD was 25.0 months. The median concentration of serum chemerin was 29.09 ng/mL. Baseline D/P Cr was positively correlated with serum chemerin (r = 0.244, p = 0.003). The multivariate analyses revealed that serum chemerin (p = 0.002), age (p = 0.041), albumin (p = 0.000), and high-density lipoprotein (p = 0.022) were independent factors of D/P Cr. The serum chemerin level was significantly higher in diabetes mellitus (DM) patients than that of patients without DM (36.45 ng/mL vs. 27.37 ng/mL, p = 0.000), and there was a significant statistical difference in CVDs between the high chemerin group (≥29.09 ng/mL) and low chemerin group (<29.09 ng/mL) (42 vs. 21%, p = 0.009).

CONCLUSIONS

Serum chemerin has a positive correlation with baseline D/P Cr in incident PD patients. It may be a biomarker that can predict the baseline transport function of the peritoneal membrane, and serum chemerin may be a risk factor of CVDs for incident PD patients. Multicenter studies with a larger sample size are warranted in the future.

Chemerin Exacerbates Psoriasis by Stimulating Keratinocyte Proliferation and Cytokine Production

OBJECTIVE

Psoriasis is often combined with metabolic abnormalities, such as obesity and diabetes. The upregulation of chemerin, which is an essential protein produced primarily from white fat, is strongly correlated to the development of psoriasis. However, there is no clarification on its exact function and mechanism in disease pathogenesis. The present study aims to determine its function and mechanism in disease pathogenesis.

METHODS

The present study used a psoriasislike inflammatory cell model and imiquimod (IMQ)-induced mouse model to confirm whether chemerin is upregulated in psoriasis patients.

RESULTS

Chemerin enhanced the keratinocyte proliferation, inflammatory cytokine secretion, and activation of the MAPK signaling pathway. Crucially, the intraperitoneal injection of neutralizing anti-chemerin antibody (ChAb) diminished the epidermal proliferation and inflammation in the IMQ-induced mouse model.

CONCLUSION

The present results indicate that chemerin promotes keratinocyte proliferation, and enhances the production of inflammatory cytokines, thereby aggravating the psoriasis. Thus, chemerin can be a prospective target for the treatment of psoriasis.

The chemerin/CMKLR1 axis regulates intestinal graft-versus-host disease

Gastrointestinal graft-versus-host disease (GvHD) is a major cause of mortality and morbidity following allogeneic bone marrow transplantation (allo-BMT). Chemerin is a chemotactic protein that recruits leukocytes to inflamed tissues by interacting with ChemR23/CMKLR1, a chemotactic receptor expressed by leukocytes, including macrophages. During acute GvHD, chemerin plasma levels were strongly increased in allo-BM-transplanted mice. The role of the chemerin/CMKLR1 axis in GvHD was investigated using Cmklr1-KO mice. WT mice transplanted with an allogeneic graft from Cmklr1-KO donors (t-KO) had worse survival and more severe GvHD. Histological analysis demonstrated that the gastrointestinal tract was the organ mostly affected by GvHD in t-KO mice. The severe colitis of t-KO mice was characterized by massive neutrophil infiltration and tissue damage associated with bacterial translocation and exacerbated inflammation. Similarly, Cmklr1-KO recipient mice showed increased intestinal pathology in both allogeneic transplant and dextran sulfate sodium-induced colitis. Notably, the adoptive transfer of WT monocytes into t-KO mice mitigated GvHD manifestations by decreasing gut inflammation and T cell activation. In patients, higher chemerin serum levels were predictive of GvHD development. Overall, these results suggest that CMKLR1/chemerin may be a protective pathway for the control of intestinal inflammation and tissue damage in GvHD.

Anti-inflammatory adipokines: chemerin, vaspin, omentin concentrations and SARS-CoV-2 outcomes

Coronavirus disease 2019 (COVID-19) is associated with systemic inflammation. A wide range of adipokines activities suggests they influence pathogenesis and infection course. The aim was to assess concentrations of chemerin, omentin, and vaspin among COVID-19 patients with an emphasis on adipokines relationship with COVID-19 severity, concomitant metabolic abnormalities and liver dysfunction. Serum chemerin, omentin and vaspin concentrations were measured in serum collected from 70 COVID-19 patients at the moment of admission to hospital, before any treatment was applied and 20 healthy controls. Serum chemerin and omentin concentrations were significantly decreased in COVID-19 patients compared to healthy volunteers (271.0 vs. 373.0 ng/ml; p < 0.001 and 482.1 vs. 814.3 ng/ml; p = 0.01, respectively). There were no correlations of analyzed adipokines with COVID-19 severity based on the presence of pneumonia, dyspnea, or necessity of Intensive Care Unit hospitalization (ICU). Liver test abnormalities did not influence adipokines levels. Elevated GGT activity was associated with ICU admission, presence of pneumonia and elevated concentrations of CRP, ferritin and interleukin 6. Chemerin and omentin depletion in COVID-19 patients suggests that this adipokines deficiency play influential role in disease pathogenesis. However, there was no relationship between lower adipokines level and frequency of COVID-19 symptoms as well as disease severity. The only predictive factor which could predispose to a more severe COVID-19 course, including the presence of pneumonia and ICU hospitalization, was GGT activity.

Biomarkers of Chronic Pancreatitis: A systematic literature review

BACKGROUND

Chronic pancreatitis (CP) does not have diagnostic or prognostic biomarkers. CP is the end stage of a progressive inflammatory syndrome that is diagnosed at late stages by morphologic features. To diagnose earlier stages of the disease, a new mechanistic definition was established based on identifying underlying pathogenic processes and biomarker evidence of disease activity and stage. Although multiple risk factors are known, the corresponding biomarkers needed to make a highly accurate diagnosis of earlier disease stages have not been established. The goal of this study is to systematically analyze the literature to identify the most likely candidates for development into biomarkers of CP.

METHODS

We conducted a systematic review of candidate analytes from easily accessible biological fluids and identified 67 studies that compared CP to nonpancreatic-disease controls. We then ranked candidate biomarkers for sensitivity and specificity by area under the receiver operator curves (AUROCs).

RESULTS

Five biomarkers had a large effect size (an AUROC > 0.96), whereas 30 biomarkers had a moderate effect size (an AUROC between 0.96 and 0.83) for distinguishing CP cases from controls or other diseases. However, the studies reviewed had marked variability in design, enrollment criteria, and biospecimen sample handling and collection.

CONCLUSIONS

Several biomarkers have the potential for evaluation in prospective cohort studies and should be correlated with risk factors, clinical features, imaging studies and outcomes. The Consortium for the Study of Chronic Pancreatitis, Diabetes and Pancreas Cancer provides recommendations for avoiding design biases and heterogeneity in sample collection and handling in future studies.

Antioxidants for Pancreatic Functions in Chronic Pancreatitis: A Double-blind Randomized Placebo-controlled Pilot Study

BACKGROUND

Antioxidants (AO) supplementation in chronic pancreatitis (CP) has been evaluated for pain. But it is not clear whether AO in CP have an effect on pancreatic functions and other clinical outcomes. We evaluated effect of AO on endocrine function in CP.

MATERIALS AND METHODS

Double-blind placebo (PL)-controlled randomized pilot study on 107 patients with CP assigned to receive daily combined AO or PL for 6 months. Primary outcome was: improvement in endocrine function (Homeostasis Model Assessment-Insulin Resistance). Secondary outcome measures were: improvement in C-peptide, Qualitative Insulin Sensitivity Check Index, exocrine pancreatic function (fecal elastase), surrogate markers of fibrosis (platelet-derived growth factor BB, transforming growth factor-β1, α-smooth muscle actin), quality of life (QOL), pain, nutritional status, markers of oxidative stress (OS), AO status, and inflammation.

RESULTS

There was an increase in levels of serum selenium (107.2±26.9 to 109.7±26.9 vs. 104.1±28.6 to 124.0±33.6 μg/L, P=0.022) and serum vitamin E [0.58 (range, 0.27-3.22) to 0.66 (range, 0.34-1.98) vs. 0.63 (range, 0.28-1.73) to 1.09 (range, 0.25-2.91) mg/dL, P=0.001] in the AO than the PL group. However, no significant differences were observed between groups in any of the primary or secondary outcome measures.

CONCLUSIONS

Supplementation with AO to patients with CP causes a sustained increase in blood levels of AO; however, it has no addition benefit over PL on endocrine and exocrine functions, markers of fibrosis, OS and inflammation, nutritional status, pain and QOL. Further larger studies with adequate sample size are required.

Diagnostic value of chemerin in lower gastrointestinal diseases-a review

Chemerin is a protein secreted among others by adipose tissue and liver, with a dual pro- and anti-inflammatory role in the body. These molecules exert systemic effects by modulating tissue-specific immune response and metabolism. Chemerin isoforms correlate with the turnover of fatty acids and lipoproteins that could affect intestinal inflammation. Although chemerin may interact with three types of receptors, CMKLR1 is the best studied. In this paper we reviewed current knowledge about the relationship between chemerin and lower gastrointestinal (GI) diseases, such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and colorectal cancer (CRC). A more detailed understanding of the role of the adipose tissue in the GI tract will not only unravel the pathophysiology of chronic intestinal diseases, but may also indicate a new therapeutic tool for their management.

Pleiotropic Associations of RARRES2 Gene Variants and Circulating Chemerin Levels: Potential Roles of Chemerin Involved in the Metabolic and Inflammation-Related Diseases

Chemerin, an adipokine and inflammatory mediator, is associated with metabolic, inflammation- and immune-mediated diseases. The genetic, clinical, and biomarker correlates of circulating chemerin levels have not been completely elucidated. We analyzed the determinants and correlates of retinoic acid receptor responder 2 (RARRES2; encoding chemerin) gene variants and chemerin levels in the Taiwanese population. In total, 612 individuals were recruited. Clinical and metabolic phenotypes, 13 inflammatory markers, 5 adipokines, and 6 single-nucleotide polymorphisms (SNPs) covering the RARRES2 region were analyzed. High chemerin levels and chemerin level tertiles were positively associated with multiple metabolic phenotypes and circulating inflammatory marker and adipokine levels and negatively associated with high-density lipoprotein cholesterol and adiponectin levels and estimated glomerular filtration rates (eGFRs). Genotype and haplotype analyses showed that RARRES2 SNPs were significantly associated with chemerin, fibrinogen, interleukin 6, and lipocalin 2 levels. Stepwise logistic regression analysis showed that C-reactive protein level, leptin level, triglyceride level, eGFR, rs3735167 genotypes, sex, and soluble P-selectin level were independently associated with chemerin levels. In conclusion, pleiotropic associations were noted between RARRES2 variants, circulating chemerin levels and multiple metabolic phenotypes and inflammatory marker levels. This study provides further evidence for the potential roles of chemerin in metabolic and inflammation-related diseases.

Relationship of circulating chemerin and omentin levels with Th17 and Th9 cell immune responses in patients with asthma

OBJECTIVE

Adipokines are correlated with immune responses in asthma, but data on the roles of chemerin and omentin in asthma are limited. This study explored the relationship of chemerin and omentin levels with Th17 and Th9 cells in asthma.

METHODS

Seventy-six asthmatics were divided into intermittent-to-mild persistent (n  =  28), moderate persistent (n  =  26) and severe persistent (n  =  22) and were enrolled in the study. Additionally, 20 healthy subjects were enrolled as controls. Clinical characteristics of the subjects, the Asthma Control Test, lung function, fractional exhaled nitric oxide score, and plasma chemerin and omentin levels were evaluated, and the percentages of Th17 and Th9 cells were determined by flow cytometry.

RESULTS

The percentages of Th17 and Th9 cells were higher in the moderate-to-severe persistent asthmatics than in the intermittent-to-mild persistent asthmatics or healthy controls (p < 0.05). The severe persistent asthma group had a higher chemerin level but lower omentin levels than the control group (p < 0.05). Chemerin levels were positively correlated with Th17 and Th9 cell percentages, while omentin levels were negatively correlated with Th17 and Th9 cell percentages (p < 0.01).

CONCLUSIONS

The regulatory functions of adipokines on immune responses may be associated with pathogenesis and processes of asthma.

Serum chemerin in children with excess body weight may be associated with ongoing metabolic complications - A pilot study

PURPOSE

The aim of this study was to verify if serum chemerin in children correlates with body weight, fat mass, selected inflammatory markers, parameters of liver function, lipid and glucose metabolism.

MATERIALS AND METHODS

The study included children aged 5-17 years with normal body weight (<85th BMI percentile, n=43) or overweight (≥85th BMI percentile, n=58). Serum concentrations of chemerin were determined with ELISA.

RESULTS

Children with excess body weight presented with significantly higher serum concentrations of chemerin. Serum chemerin correlated positively with body weight, absolute BMI and its percentile, fat mass, systolic blood pressure, CRP, ALT, insulin and HOMA-IR.

CONCLUSIONS

Serum level of chemerin may serve as a measure of ongoing obesity-related inflammation, early marker of subclinical liver dysfunction and metabolic syndrome in overweight pediatric patients.

Methodological utility of chemerin as a novel biomarker of immunity and metabolism

Chemerin is a recently discovered adipokine with inflammatory and metabolic actions relevant for chronic disease development. However, evidence from human research on the role of chemerin in chronic disease risk is still lacking. We assessed the reliability of plasma chemerin concentrations measured on two occasions over a 4-month period in 207 apparently healthy participants. In addition, we explored the cross-sectional associations between chemerin and inflammatory biomarkers using Spearman partial correlation and multivariable linear regression analyses. Intra-individual reproducibility of chemerin measurements was assessed by calculating intraclass correlation coefficients (ICCs) and exploration of Bland-Altman plots. Reliability analyses revealed good reproducibility of chemerin measurements (ICC: 0.72 (95%-CI 0.65, 0.78)). Visual inspection of Bland-Altman plots confirmed that the two time point measurements had a high level of agreement. In correlation analyses, chemerin was positively correlated with adiposity measures (body mass index and waist circumference). In addition, independent of adiposity measures, chemerin was correlated with the biomarkers C-reactive protein, fatty acid-binding protein 4 and progranulin (Rho-s ranging from 0.23 to 0.37). In multivariable linear regression analysis, a combination of correlated factors including body mass index, waist circumference, C-reactive protein, progranulin and fatty acid-binding protein-4 explained 28.0% of chemerin concentrations. These findings demonstrate methodological utility of chemerin concentrations in population-based research setting. Human studies are highly warranted in order to provide further insights into the role of chemerin as a biomarker linking immunity and metabolism in relation to chronic disease risk.

Chemokine-Like Receptor 1 Regulates the Proliferation and Migration of Vascular Smooth Muscle Cells

Background

We aimed to explore how chemokine-like receptor 1 (CMKLR1) influences the proliferation and migration of vascular smooth muscle cells (VSMCs).

Material/Methods

Normal VSMCs, negative control VSMCs interfered by CMKLR1 gene, and VSMCs with stable knockdown of CMKLR1 gene were divided into the control group, PDGF group, negative-shRNA group, and CMKLR1-shRNA group. Both cell number counting and BrdU incorporation assays were employed to investigate the proliferation status of VSMCs. Transwell migration assay was used to measure the migration status of VSMCs. Inflammation markers, including cytokines IL-1β, IL-6, TNF-α, and chemokines MCP-1 in VSMCs, were detected by real-time quantitative RT-PCR. Western blotting assay was used to detect protein expressions of the MAPK pathway in VSMCs.

Results

The number of VSMCs and the OD value of BrdU in PDGF group were significantly higher than those in the control group (both P<0.05). Compared with the control and negative-shRNA group, the CMKLR1-shRNA group exhibited significantly reduced VSMCs number and BrdU OD value (both P<0.05). Transwell migration assay indicated that PDGF-BB promoted whereas CMKLR1-shRNA inhibited the migration of VSMCs. The expression of IL-1β, IL-6, TNF-α, and MCP-1 were up-regulated in the PDGF group but down-regulated in the CMKLR1-shRNA group. Compared with normal VSMCs, the protein level of p-ERK1/2 was up-regulated in VSMCs treated with PDGF-BB, while it was down-regulated in the CMKLR1-shRNA group.

Conclusions

CMKLR1 exacerbated the proliferation and migration of VSMCs by activating ERK1/2.

Chronic pancreatitis: Do serum biomarkers provide an association with an inflammageing phenotype?

BACKGROUND

Chronic pancreatitis is an inflammatory disorder of the pancreas that is associated with accelerated mortality for patients suffering from this disease. The association between chronic inflammation and accelerated biological ageing has been well described and is often referred to as "inflammageing". In this review we seek to determine how systemic inflammation in chronic pancreatitis may contribute to an accelerated ageing phenotype.

METHODS

A systematic literature search with a predefined search protocol was performed on Medline, Embase and Cochrane libraries according to the PRISMA guidelines.

RESULTS

The initial search identified 499 studies. After title, abstract and full text screen of the search results, 20 were included for further evaluation. In the 20 remaining articles 41 inflammatory mediators were identified - mainly involved in chronic inflammation, fibrosis and particularly cardinal features of inflammageing such as sarcopenia and osteoporosis.

CONCLUSION

Chronic pancreatitis is associated with elevated levels of inflammatory mediators many of which are associated with an accelerated ageing phenotype and may explain some of the clinical sequelae of this disease.

Association of serum chemerin concentrations with the presence of atrial fibrillation

Objective Chemerin, a newly discovered adipokine, is correlated with hypertension, diabetes and coronary heart disease. The aim of this study is to investigate the association of serum chemerin concentrations with the presence of atrial fibrillation. Methods Serum chemerin concentrations were determined in 256 patients with atrial fibrillation and 146 healthy subjects. Atrial fibrillation patients were then divided into paroxysmal, persistent and permanent atrial fibrillation. Results Serum chemerin concentrations were significantly higher in atrial fibrillation patients compared with healthy controls. In subgroup studies, patients with permanent atrial fibrillation had higher serum chemerin concentrations than those with persistent and paroxysmal atrial fibrillation. Furthermore, significant higher serum chemerin concentrations were observed in persistent atrial fibrillation patients compared with paroxysmal atrial fibrillation subjects. Serum chemerin concentrations were associated with the presence of atrial fibrillation after logistic regression analysis. Pearson correlation analysis revealed a positive relation of serum chemerin concentrations with body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, low-density lipoprotein cholesterol, blood urea nitrogen, creatinine, C-reactive protein and left atrial diameter. Conclusion Serum chemerin concentrations are associated with the presence of atrial fibrillation and atrial remodelling.

Circulating serum chemerin levels are elevated in lipodystrophy

OBJECTIVE

Lipodystrophy (LD) is characterized by loss of adipose tissue, dysregulation of adipokines and severe metabolic complications. Regulation of the insulin resistance-inducing and proinflammatory adipokine chemerin has not been assessed in LD. Therefore, we determined chemerin serum levels in LD, chemerin mRNA expression in insulin-sensitive tissues of LD mice, as well as the impact of metreleptin treatment on circulating chemerin in LD patients.

RESEARCH DESIGN AND METHODS

Serum chemerin, as well as clinical and biochemical parameters of glucose metabolism, lipid metabolism, and inflammation, was measured in 37 LD patients and 37 age-, gender- and body mass index-matched controls. Furthermore, chemerin mRNA expression was determined in LD mice and controls. Moreover, circulating chemerin was assessed at five different time points in 10 LD patients treated with metreleptin over 1 year.

RESULTS

Median serum chemerin levels were significantly higher in 37 subjects with LD (234·3 μg/l) as compared to controls (204·0 μg/l) (P = 0·002). Multiple linear regression analysis showed that circulating chemerin was independently and positively associated with glycosylated haemoglobin A1c (HbA1c) and C-reactive protein (CRP). Chemerin mRNA expression was significantly increased 2·5-fold in visceral adipose tissue (VAT) and 5·3-fold in brown adipose tissue (BAT) of LD mice as compared to controls (P < 0·01). Circulating chemerin was not significantly altered by metreleptin treatment.

CONCLUSIONS

Circulating levels of the adipokine chemerin are elevated in LD, as well as independently and positively associated with HbA1c and CRP. Increased chemerin might originate from VAT and BAT.

Inverse Relationship of the CMKLR1 Relative Expression and Chemerin Serum Levels in Obesity with Dysmetabolic Phenotype and Insulin Resistance

Background. In obesity there is a subclinical chronic low-grade inflammatory response where insulin resistance (IR) may develop. Chemerin is secreted in white adipose tissue and promotes low-grade inflammatory process, where it expressed CMKLR1 receptor. The role of chemerin and CMKLR1 in inflammatory process secondary to obesity is not defined yet. Methods. Cross-sectional study with 134 individuals classified as with and without obesity by body mass index (BMI) and IR. Body fat storage measurements and metabolic and inflammatory markers were measured by routine methods. Soluble chemerin and basal levels of insulin by ELISA and relative expression of CMKLR1 were evaluated with qPCR and 2^−ΔΔC_T method. Results. Differences (P < 0.05) were observed between obesity and lean individuals in body fat storage measurements and metabolic-inflammatory markers. Both CMKLR1 expression and chemerin levels were increased in obesity without IR. Soluble chemerin levels correlate with adiposity and metabolic markers (r = 8.8% to 38.5%), P < 0.05. Conclusion. The increment of CMKLR1 expression was associated with insulin production. Increased serum levels of chemerin in obesity were observed, favoring a dysmetabolic response. The results observed in this study suggest that both chemerin and CMKLR1 have opposite expression in the context of low-grade inflammatory response manifested in the development of IR.

Chemerin as an independent predictor of cardiovascular event risk

Currently, coronary artery disease (CAD) is considered a major ailment in humans with widespread prevalence. CAD also accounts for high mortality rates around the world that involves several known risk factors. Chemerin is a novel adipokinine that is associated with inflammation and adipogenesis. Furthermore, experimental and clinical data indicate that localized as well as circulating chemerin expression and activation are elevated in numerous metabolic and inflammatory diseases including psoriasis, obesity, type 2 diabetes, metabolic syndrome and cardiovascular disease. Chemerin is accepted as being a strong marker because the serum chemerin levels are increased in a CAD condition. However, the chimeric characteristics of chemerin have not been fully investigated. Although chemerin is known to be responsible for CAD development among other factors, authors still investigate it at the marker level. This review focuses on chemerin expression, processing, biological function and relevance to human diseases, and on the role of chemerin in the maintenance of a cardiovascular disease.

Chemerin in peritoneal sepsis and its associations with glucose metabolism and prognosis: a translational cross-sectional study

BACKGROUND

Stress hyperglycaemia (SHG) is a common complication in sepsis associated with poor outcome. Chemerin is an adipocytokine associated with inflammation and impaired glucose homeostasis in metabolic diseases such as type 2 diabetes (T2D). We aimed to investigate how alterations of circulating chemerin levels and corresponding visceral adipose tissue (VAT) expression are linked to glucose metabolism and prognosis in sepsis.

METHODS

Clinical data and tissue samples were taken from a cross-sectional study including control, T2D and sepsis patients, all undergoing laparotomy. A second independent patient cohort of patients with sepsis was included to evaluate associations with prognosis. This was complemented by a murine model of peritoneal infection and a high-fat diet. We analysed circulating chemerin by enzyme-linked immunosorbent assay and VAT messenger RNA (mRNA) expression by real-time polymerase chain reaction.

RESULTS

Circulating chemerin was increased in sepsis 1.69-fold compared with controls (p = 0.012) and 1.47-fold compared with T2D (p = 0.03). Otherwise, chemerin VAT mRNA expression was decreased in patients with sepsis (p = 0.006) and in septic diabetic animals (p = 0.009). Circulating chemerin correlated significantly with intra-operative glucose (r = 0.662; p = 0.01) and in trend with fasting glucose (r = 0.528; p = 0.052). After adjusting for body mass index or haemoglobin A1c, chemerin correlated in trend with insulin resistance evaluated using the logarithmised homeostasis model assessment of insulin resistance (r = 0.539, p = 0.071; r = 0.553, p = 0.062). Chemerin was positively associated with Acute Physiology and Chronic Health Evaluation II score in patients with sepsis (p = 0.036) and with clinical severity in septic mice (p = 0.031). In an independent study population, we confirmed association of chemerin with glucose levels in multivariate linear regression analysis (β = 0.556, p = 0.013). In patients with sepsis with SHG, non-survivors had significantly lower chemerin levels than survivors (0.38-fold, p = 0.006), while in patients without SHG, non-survivors had higher chemerin levels, not reaching significance (1.64-fold, p = 0.089). No difference was apparent in patients with pre-existing T2D (p = 0.44).

CONCLUSIONS

We show, for the first time to our knowledge, that chemerin is increased in sepsis and that it associates with impaired glucose metabolism and survival in these patients. It could be further evaluated as a biomarker to stratify mortality risk of patients with SHG.

New roles of the multidimensional adipokine: chemerin

The discovery of several adipokines with diverse activities and their involvement in regulation of various pathophysiological functions of human body has challenged the researchers. In the family of adipokine, chemerin is a novel and unique addition. Ever since the first report on chemerin as a chemo-attractant protein, there are numerous studies showing a multitasking capacity of chemerin in the maintenance of homeostasis, for the activation of natural killer cells, macrophages and dendritic cells in both innate and adaptive immunity. Its diversity ranges from generalized inflammatory cascades to being explicitly involved in the manifestation of arthritis, psoriasis and peritonitis. Its association with certain cancerous tissue may render it as a potential tumor marker. In present review, we aim to consolidate recent data of investigations on chemerin in context to functional characteristics with a special reference to its role as a metabolic signal in inflammation and non-metabolic syndromes.

Decreased serum platelet derived growth factor BB levels in acute and increased in chronic pancreatitis

AIM: To examine circulating growth factor concentrations in patients with acute pancreatitis (AP) and chronic pancreatitis (CP), and walled-off pancreatic necrosis (WOPN).

METHODS: Forty patients with mild AP, 40 patients with alcoholic CP, 33 patients with WOPN and 40 healthy subjects were examined. Serum concentrations of platelet derived growth factor BB (PDGF-BB), transforming growth factor β-1 (TGFβ-1), chemerin and high-mobility group box chromosomal protein 1 (HMBG1) were assayed by enzyme linked immunosorbent assay.

RESULTS: Patients with mild AP and those with WOPN had significantly lower serum levels of PDGF-BB compared to healthy subjects (4.0 ± 0.61 ng/mL vs 6.2 ± 0.76 ng/mL, P = 0.027, and 1.60 ± 0.31 ng/mL vs 6.2 ± 0.76 ng/mL, P < 0.001, respectively), while CP was associated with higher serum levels of PDGF-BB (12 ± 1.3 ng/mL vs 6.2 ± 0.76 ng/mL, P < 0.001). Circulating TGFβ-1 and chemerin levels were elevated in CP patients (57 ± 3.6 ng/mL vs 39 ± 3.6 ng/mL, P < 0.001 and 73 ± 7.2 ng/mL vs 48 ± 2.3 ng/mL, P < 0.001, respectively), but not in patients with AP and WOPN. No significant changes in serum HMBG1 levels were found either in patients with AP, WOPN or CP.

CONCLUSION: The serum levels of some growth factors and cytokines differ significantly in AP, WOPN and CP. These data suggest that selected growth factors and cytokines may be considered as potential diagnostic biomarkers in patients with pancreatic diseases.

Evaluation of plasma chemerin levels in patients with non-dipper blood pressure patterns

BACKGROUND

Chemerin is a novel adipokine that plays a role in inflammation and atherosclerosis. Although there are several correlations between hypertension and the inflammatory system, there is still insufficient information about the relationship between blood pressure variability and inflammatory markers. In this study, we aimed to determine whether chemerin levels are elevated in non-dipper patients compared with dippers and healthy controls.

MATERIAL AND METHODS

This study was composed of a group of 90 patients: 60 hypertensive patients and 30 healthy control subjects (12 males, mean age 53.2 ± 15.4 years). Ambulatory blood pressure monitoring devices (ABPM) were connected to all patients. Using data from the ABPM, hypertensive patients were divided into 2 groups: 30 dipper patients (12 males, mean age 52.5 ± 15.1 years) and 30 non-dipper patients (11 males, mean age 54.6 ± 13.0 years). Complete blood count and biochemistry were measured by standard methods and plasma chemerin concentrations were quantified by ELISA.

RESULTS

Non-dipper patients demonstrated higher chemerin levels compared to dippers and normotensives (219.7 ± 16.3 vs. 182.4 ± 21.4 ng/ml; 219.7 ± 16.3 vs. 85.4 ± 38.1 ng/ml, respectively, p<0.001 for both comparisons). A receiver operating characteristic curve analysis revealed that the optimal cut-off value for chemerin to predict a non-dipping pattern was 201.4, with 90% sensitivity and 90% specificity. There was a positive correlation between chemerin levels and all ambulatory blood pressure values in all hypertensive patients.

CONCLUSIONS

Chemerin, which plays a role in inflammation and atherosclerosis, was higher in non-dippers compared to dippers and normotensives. Additionally, chemerin shows positive correlations with blood pressure.

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.