New roles of the multidimensional adipokine: chemerin

Comprehensive Quality Analysis of Conventional and Novel Biomarkers in Diagnosing and Predicting Prognosis of Coronary Artery Disease, Acute Coronary Syndrome, and Heart Failure, a Comprehensive Literature Review

Coronary artery disease (CAD), acute coronary syndrome (ACS), and heart failure (HF) are major global health issues with high morbidity and mortality rates. Biomarkers like cardiac troponins (cTn) and natriuretic peptides (NPs) are crucial tools in cardiology, but numerous new biomarkers have emerged, proving increasingly valuable in CAD/ACS. These biomarkers are classified based on their mechanisms, such as fibrosis, metabolism, inflammation, and congestion. The integration of established and emerging biomarkers into clinical practice is an ongoing process, and recognizing their strengths and limitations is crucial for their accurate interpretation, incorporation into clinical settings, and improved management of CVD patients. We explored established biomarkers like cTn, NPs, and CRP, alongside newer biomarkers such as Apo-A1, IL-17E, IgA, Gal-3, sST2, GDF-15, MPO, H-FABP, Lp-PLA2, and ncRNAs; provided evidence of their utility in CAD/ACS diagnosis and prognosis; and empowered clinicians to confidently integrate these biomarkers into clinical practice based on solid evidence.

Comparative Evaluation of Adipokine Metrics for the Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the most common medical disorders in pregnancy. Adipokines, predominantly secreted by adipose tissue, are involved in numerous metabolic processes. The exact role of adipokines in the pathogenesis of GDM is still not well known, and numerous adipokines have been analysed throughout pregnancy and proposed as biomarkers of GDM. This study aimed to evaluate serum adiponectin, chemerin, lipocalin and apelin levels in GDM and non-GDM women, to assess them as clinically useful biomarkers of the occurrence of GDM and to demonstrate the correlation between the levels of the above adipokines in the blood serum and the increased risk of the development of GDM. The role of these adipokines in the pathogenesis of GDM was also analysed. The statistically significant differences between the levels of adiponectin (7234.6 vs. 9837.5 ng/mL, p < 0.0001), chemerin (264.0 vs. 206.7 ng/mL, p < 0.0001) and lipocalin (39.5 vs. 19.4 ng/mL, p < 0.0001) were observed between pregnant women with GDM and healthy ones. The diagnostic usefulness of the tested adipokines in detecting GDM was also assessed. The research results confirm the hypothesis on the significance of adiponectin, chemerin, lipocalin and apelin in the pathophysiological mechanisms of GDM. We speculate that these adipokines could potentially be established as novel biomarkers for the prediction and early diagnosis of GDM.

Adipokines and Their Role in Heart Failure: A Literature Review

Obesity is a major risk factor for heart failure (HF). The relationship between adipokines and HF has been implicated in many previous studies and reviews. However, this review article summarizes the basic role of major adipokines, such as apelin, adiponectin, chemerin, resistin, retinol-binding protein 4 (RBP4), vaspin, visfatin, plasminogen activator inhibitor-1, monocyte chemotactic protein-1, nesfatin-1, progranulin, leptin, omentin-1, lipocalin-2, and follistatin-like 1 (FSTL1), in the pathogenesis of HF. Apelin is reduced in patients with HF and upregulated following favorable left ventricular (LV) remodeling. Higher levels of adiponectin have been found in patients with HF compared to in control patients. Also, high plasma chemerin levels are linked to a higher risk of HF. Serum resistin is related to the severity of HF and associated with a high risk for adverse cardiac events. Evidence indicates that RBP4 can contribute to inflammation and damage heart muscle cells, potentially leading to HF. Vaspin might stop the progression of cardiac degeneration, fibrosis, and HF according to experiments on rats with experimental isoproterenol-induced chronic HF. The serum concentrations of visfatin are significantly lower in patients with systolic HF. Leptin levels were found to be correlated with low LV mass and myocardial stiffness, both of which are significant risk factors for the development of HF with preserved ejection fraction (HFpEF). Measuring serum omentin-1 levels appears to be a novel prognostic indicator for risk stratification in HF patients. Increased expression of neutrophil gelatinase-associated lipocalin in both systemic circulation and myocardium in clinical and experimental HF suggests that innate immune responses may contribute to the development of HF. FSTL1 was elevated in patients with HF with reduced ejection fraction and associated with an increase in the size of the left ventricle of the heart. However, other adipokines, such as plasminogen activator inhibitor-1, monocyte chemotactic protein-1, nesfatin-1, and progranulin, have not yet been studied for HF.

Is Chemerin Associated with Gestational Diabetes Mellitus? A Case-Control Study

Purpose

The aim of this study was to investigate the relationship between gestational diabetes mellitus (GDM) and Chemerin by analyzing chemerin levels in peripheral blood and cord blood, and chemerin mRNA and its protein expression in placenta and adipose tissue.

Methods

A case-control study was conducted in 110 women with GDM and 110 controls without GDM who received regular prenatal services and delivered at Shanghai Pudong New Area Healthcare Hospital for Women and Children from June 2019 to December 2020.

Results

The age, pre-pregnancy weight, pre-pregnancy BMI, antepartum BMI, TG/HDL ratio and TG levels in pregnant women with GDM were significantly higher than those in women without GDM, and HDL levels were significantly lower than those in the normal group. Chemerin in the umbilical cord blood of the GDM group was significantly higher than in that of the normal group, but there was no difference in chemerin levels in peripheral blood. In the two groups, the chemerin concentration in peripheral blood was significantly higher than that in umbilical cord blood (P<0.001). The Chemerin mRNA and protein expression levels in the placenta and adipose tissue of pregnant women in the GDM group were significantly higher than those in the normal group (P <0.001). In the GDM group, the expression of chemerin protein in adipose tissue was significantly higher than that in placental tissue. Regression analysis showed that the expression level of chemerin protein in placental tissue and adipose tissue was positively correlated with the risk of GDM.

Conclusion

Elevated chemerin is closely related to the risk of GDM, and the placenta may be an important secretion of chemotactic factor sources in addition to adipose tissue and participate in the development of GDM.

CMKLR1 Antagonist Alpha-NETA Protects against Diabetic Nephropathy in Mice

INTRODUCTION

Diabetic nephropathy (DN) is a common complication in diabetic patients. Chemerin, a novel adipokine, has been associated with renal damage in DN. The chemerin chemokine-like receptor 1 (CMKLR1) has been reported to participate in DN. In this study, we aimed to investigate the effect of a CMKLR1 antagonist, 2-(anaphthoyl)ethyltrimethylammonium iodide (α-NETA), on DN.

METHODS

To induce diabetes, 8-week-old male C57BL/6J mice were given a single intraperitoneal injection of 65 mg/kg streptozotocin (STZ). Diabetic mice were randomly assigned to receive daily doses of 0, 5, or 10 mg/kg α-NETA for 4 weeks.

RESULTS

α-NETA dose-dependently induced body weight and reduced fasting blood glucose levels in STZ-induced diabetic mice. Furthermore, α-NETA significantly reduced the expressions of renal injury markers, including serum creatinine, kidney weight/body weight, urine volume, total proteins, and albumin in the urine, and increased creatinine clearance. Periodic acid-Schiff staining also indicated that α-NETA could effectively ameliorate renal injuries in DN mice. In addition, α-NETA inhibited renal inflammation and the expressions of chemerin and CMKLR1 in mice with DN.

CONCLUSION

In summary, our findings suggested that α-NETA has beneficial effects on the management of DN. Specifically, α-NETA effectively ameliorated renal damage and inflammation in a dose-dependent manner in mice with DN. Thus, targeting the chemerin and CMKLR1 axis with α-NETA may be a promising therapeutic strategy for the treatment of DN.

The Role of Adipokines in Health and Disease

Adipokines are cell-signaling proteins secreted by adipose tissue that has been related to a low-grade state of inflammation and different pathologies. The present review aims to analyze the role of adipokines in health and disease in order to understand the important functions and effects of these cytokines. For this aim, the present review delves into the type of adipocytes and the cytokines produced, as well as their functions; the relations of adipokines in inflammation and different diseases such as cardiovascular, atherosclerosis, mental diseases, metabolic disorders, cancer, and eating behaviors; and finally, the role of microbiota, nutrition, and physical activity in adipokines is discussed. This information would allow for a better understanding of these important cytokines and their effects on body organisms.

Fecal and Urinary Adipokines as Disease Biomarkers

The use of biomarkers is of great clinical value for the diagnosis and prognosis of disease and the assessment of treatment efficacy. In this context, adipokines secreted from adipose tissue are of interest, as their elevated circulating levels are associated with a range of metabolic dysfunctions, inflammation, renal and hepatic diseases and cancers. In addition to serum, adipokines can also be detected in the urine and feces, and current experimental evidence on the analysis of fecal and urinary adipokine levels points to their potential as disease biomarkers. This includes increased urinary adiponectin, lipocalin-2, leptin and interleukin-6 (IL-6) levels in renal diseases and an association of elevated urinary chemerin as well as urinary and fecal lipocalin-2 levels with active inflammatory bowel diseases. Urinary IL-6 levels are also upregulated in rheumatoid arthritis and may become an early marker for kidney transplant rejection, while fecal IL-6 levels are increased in decompensated liver cirrhosis and acute gastroenteritis. In addition, galectin-3 levels in urine and stool may emerge as a biomarker for several cancers. With the analysis of urine and feces from patients being cost-efficient and non-invasive, the identification and utilization of adipokine levels as urinary and fecal biomarkers could become a great advantage for disease diagnosis and predicting treatment outcomes. This review article highlights data on the abundance of selected adipokines in urine and feces, underscoring their potential to serve as diagnostic and prognostic biomarkers.

Chemerin and Chemokine-like Receptor 1 Expression in Ovarian Cancer Associates with Proteins Involved in Estrogen Signaling

Chemerin, a pleiotropic adipokine coded by the RARRES2 gene, has been reported to affect the pathophysiology of various cancer entities. To further approach the role of this adipokine in ovarian cancer (OC), intratumoral protein levels of chemerin and its receptor chemokine-like receptor 1 (CMKLR1) were examined by immunohistochemistry analyzing tissue microarrays with tumor samples from 208 OC patients. Since chemerin has been reported to affect the female reproductive system, associations with proteins involved in steroid hormone signaling were analyzed. Additionally, correlations with ovarian cancer markers, cancer-related proteins, and survival of OC patients were examined. A positive correlation of chemerin and CMKLR1 protein levels in OC (Spearman's rho = 0.6, p < 0.0001) was observed. Chemerin staining intensity was strongly associated with the expression of progesterone receptor (PR) (Spearman´s rho = 0.79, p < 0.0001). Both chemerin and CMKLR1 proteins positively correlated with estrogen receptor β (ERβ) and estrogen-related receptors. Neither chemerin nor the CMKLR1 protein level was associated with the survival of OC patients. At the mRNA level, in silico analysis revealed low RARRES2 and high CMKLR1 expression associated with longer overall survival. The results of our correlation analyses suggested the previously reported interaction of chemerin and estrogen signaling to be present in OC tissue. Further studies are needed to elucidate to which extent this interaction might affect OC development and progression.

Urinary chemerin as a potential biomarker for inflammatory bowel disease

Purpose

Systemic levels of the adipokine chemerin are elevated in different inflammatory conditions such as inflammatory bowel disease (IBD). In IBD, chemerin protein expression in colon mucosa is induced and serum chemerin levels are increased. Aim of this study was to identify chemerin protein in human feces and/or urine and to evaluate a possible association with IBD activity.

Materials and methods

Feces and urine of 40 patients with IBD and the respective sera of 34 patients were collected. Chemerin levels were analyzed by immunoblot in feces and urine samples. In addition, enzyme-linked immunosorbent assay (ELISA) was used to measure chemerin in all urine, feces and serum samples of the patients and in urine of 17 healthy controls.

Results

Chemerin was not detectable in 80% of the human feces samples by ELISA. Chemerin in human urine was detected by immunoblot and ELISA. Compared to serum levels, urinary concentration was about 6,000-fold lower. Urinary chemerin did not differ between patients with ulcerative colitis (n = 15) and Crohn's disease (n = 25). Urinary chemerin was not related to its serum levels, did not correlate with serum C-reactive protein level and negatively correlated with serum creatinine. Of note, urinary chemerin of patients with a fecal calprotectin > 500 μg/g was significantly higher compared to patients with lower calprotectin levels and compared to healthy controls. Serum creatinine did not differ between the patient groups.

Conclusion

Urinary chemerin might present a novel non-invasive biomarker for monitoring IBD severity and clinical course.

Chemerin-Induced Down-Regulation of Placenta-Derived Exosomal miR-140-3p and miR-574-3p Promotes Umbilical Vein Endothelial Cells Proliferation, Migration, and Tube Formation in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) leads to poor pregnancy outcomes and fetoplacental endothelial dysfunction; however, the underlying mechanisms remain unknown. This study aimed to investigate the effect of placenta-derived exosomal miRNAs on fetoplacental endothelial dysfunction in GDM, as well as to further explore the role of chemerin to this end. Placenta-derived exosomal miR-140-3p and miR-574-3p expression (next-generation sequencing, quantitative real-time PCR), its interactions with cell function (Cell Counting Kit-8, Transwell, tube formation assay), chemerin interactions (Western blotting), and placental inflammation (immunofluorescence staining, enzyme-linked immunosorbent assay) were investigated. Placenta-derived exosomal miR-140-3p and miR-574-3p were downregulated in GDM. Additionally, miR-140-3p and miR-574-3p inhibited the proliferation, migration, and tube formation ability of umbilical vein endothelial cells by targeting vascular endothelial growth factor. Interestingly, miR-140-3p and miR-574-3p expression levels were negatively correlated with chemerin, which induced placental inflammation through the recruitment of macrophage cells and release of IL-18 and IL-1β. These findings indicate that chemerin reduces placenta-derived exosomal miR-140-3p and miR-574-3p levels by inducing placental inflammation, thereby promoting the proliferation, migration, and tube formation of umbilical vein endothelial cells in GDM, providing a novel perspective on the underlying pathogenesis and therapeutic targets for GDM and its offspring complications.

Effect of Ibandronate Therapy on Serum Chemerin, Vaspin, Omentin-1 and Osteoprotegerin (OPG) in Postmenopausal Osteoporotic Females

Osteoporosis is a condition in which bone mineral density is reduced due to altered bone microstructure, which results in increased skeletal fragility and incidence of various types of fractures. Adipokines such as chemerin, vaspin, omentin-1 and osteoprotegerin are involved in bone remodeling. The current study was designed to determine the changes in circulating chemerin, vaspin, omentin-1, and osteoprotegerin levels after treatment with oral ibandronate 150 mg in postmenopausal osteoporotic females. The present study enrolled 107 postmenopausal osteoporotic females from a tertiary care hospital in Faisalabad, Pakistan, based on stringent inclusion and exclusion criteria. Sixty-six healthy postmenopausal, non-osteoporotic females with no systemic illness were chosen from the general population. The assessment of bone mineral density (BMD) was done using a DEXA scan. Serum levels of chemerin, vaspin, omentin-1 and osteoprotegerin were estimated using commercially available enzyme-linked immunosorbent assay kits. The collected data were analyzed with the Statistical Package for Social Sciences (SPSS) version 24. Following 6 months of ibandronate treatment, there was a significant decrease of 24.24% (p < .033) in serum chemerin levels, as well as a significant increase in serum vaspin levels 343.32% (p < .001) and osteoprotegerin levels 19.57% (p < .001), with no significant change in omentin-1 levels. Thus, an increase in serum chemerin levels and a decrease in serum vaspin and osteoprotegerin levels could be implicated in osteoporosis.

Role of chemerin in the control of glucose homeostasis

Chemerin is an adipokine produced by the white adipose tissue and other tissues, which plays various roles in the pathogenesis of inflammatory and metabolic diseases in multiple organs. The present review aims at gathering scientific evidence reported in the last ten years, concerning the relationship of chemerin with alterations of glycaemic control, such as insulin resistance, type 2 diabetes and gestational diabetes in humans. Although the vast majority of the studies have shown a positive correlation between the chemerin level and a bad glycaemic control, a general consensus has not been reached. The reported results come from case-control and observational longitudinal studies, thereby limiting their interpretation. In fact, it cannot be stated whether insulin resistance and diabetes lead to an increase in chemerin levels or, on the contrary, if high levels of chemerin contribute to an impaired glycaemic control. Elevated levels of circulating chemerin are also associated with gestational diabetes mellitus. Chemerin gene polymorphisms could be proposed as mediators of glucose-related diseases. Nevertheless, to date very little is known about their implication in glucose metabolism. With regard to the mechanisms of action, chemerin impairs insulin cascade signaling by acting on several proteins of this cascade and by inducing inflammation.

The role of vitamin D deficiency and elevated inflammatory biomarkers as risk factors for the progression of diabetic nephropathy in patients with type 2 diabetes mellitus

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. Albuminuria is the most sensitive marker for the early recognition of DN. Therefore, we aimed to study the risk factors of albuminuria as a marker of DN among diabetic patients. The study included 41 patients with type 2 diabetes mellitus (T2DM), 50 type 2 diabetic nephropathy (T2DN) patients with macroalbuminuria, 43 T2DN patients with microalbuminuria and 38 healthy controls. Logistic regression was used to detect the most significant risk factors for albuminuria. A high statistically significant difference was found between the groups regarding age, sex, body mass index (BMI), diabetes mellitus (DM) duration, glucose, glycated haemoglobin (HbA1c), creatinine, glomerular filtration rate (GFR), lipid profile, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), the albumin–creatinine ratio (ACR), vitamin D, total parathyroid hormone (PTH), urea, total calcium and chemerin (p < 0.001). It was found that the duration of DM, BMI, glucose, GFR, total cholesterol (TC), low-density lipoprotein (LDL), TNF-α, IL-6, CRP, ACR, vitamin D, PTH and chemerin are significant albuminuria risk factors in DN. Vitamin D deficiency and associated inflammatory mediators such as chemerin, TNF-α, IL-6 and CRP are the most essential risk factors for albuminuria in T2DM patients.

Discovery of chemerin as the new chemoattractant of human mesenchymal stem cells

Background

The homing capacity of human mesenchymal stem cells (hMSCs) to the injured sites enables systemic administration of hMSCs in clinical practice. In reality, only a small proportion of MSCs are detected in the target tissue, which is a major bottleneck for MSC-based therapies. We still don’t know the mechanism how MSCs are chemo-attracted to certain target organ and engrafted through trans-endothelial migration. In this study, we aimed to determine the mechanism how the circulating hMSCs home to the injured liver.

Methods and results

When we compare the cytokine array between normal and injured mouse liver at 1-day thioacetamide (TAA)-treatment, we found that chemerin, CXCL2, and CXCL10 were higher in the injured liver than normal one. Among three, only chemerin was the chemoattractant of hMSCs in 2D- and 3D-migration assay. Analysis of the signal transduction pathways in hMSCs showed that chemerin activated the phosphorylation of JNK1/2, ERK1/2 and p38, and finally upregulated CD44, ITGA4, and MMP-2 that are involved in the transendothelial migration and extravasation of MSCs. Upstream transcription regulators of CD44, ITGA4, and MMP-2 after chemerin treatment were MZF1, GATA3, STAT3, and STAT5A. To develop chemerin as a chemoattractant tool, we cloned gene encoding the active chemerin under the CMV promoter (CMV-aChemerin). We analyzed the migration of hMSCs in the 3D model for space of the Disse, which mimics transmigration of hMSCs in the liver. CMV-aChemerin-transfected hepatocytes were more effective to attract hMSC than control hepatocytes, leading to the enhanced transendothelial migration and homing of hMSCs to liver. The homing efficiency of the intravascularly-delivered hMSCs to liver was evaluated after systemic introduction of the CMV-aChemerin plasmid packed in liposome-vitamin A conjugates which target liver. CMV-aChemerin plasmid targeting liver significantly enhanced homing efficiency of hMSCs to liver compared with control plasmid vector.

Conclusions

Chemerin is the newly found chemoattractant of hMSCs and may be a useful tool to manipulate the homing of the intravascularly-administered hMSC to the specific target organ.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00631-3.

Association of serum chemerin with calcium, alkaline phosphatase and bone mineral density in postmenopausal females

OBJECTIVES

To investigate the association of serum chemerin with calcium, alkaline phosphatase and bone mineral density in postmenopausal non-osteoporotic and osteoporotic females.

METHODS

This cross-section analysis was carried out at the orthopedic department of Madina Teaching Hospital, Faisalabad, Pakistan, in the year 2017-2019. Postmenopausal females were divided into two groups according to their bone mineral density (BMD). All osteoporotic females had a T-score of -2.5 or less. Data were analyzed on SPSS-24.

RESULTS

A total of 140 women were included in our study (80 osteoporotic and 60 non-osteoporotic). Non significant difference in age and BMI was observed between osteoporotic and non-osteoporotic subjects (p=0.152) and (p=0.291) respectively. There was a significant difference found in total BMD, serum chemerin levels between osteoporotic and non-osteoporotic subjects p<0.001 in both parameters. No significant correlation of serum chemerin was found with serum calcium, serum alkaline phosphatase and BMD in postmenopausal osteoporotic females (p=0.907), (p=0.318) (p=0.664) respectively. A significant negative correlation was found between serum alkaline phosphatase levels and total BMD in postmenopausal osteoporotic females (p=- 0.039). Linear regression analysis of serum alkaline phosphatase levels with total BMD showed no association between BMD and serum alkaline phosphatase levels (p=0.869).

CONCLUSION

There is no association of serum chemerin with calcium, ALP and bone mineral density in non-osteoporotic and osteoporotic postmenopausal females.

Chemerin in inflammatory diseases

Obesity is associated with a series of health problems. Adipocytes are a huge repository of energy as well as an important source of many adipokines. In obesity, adipocytes are dysfunctional with excessive production and secretion of pro-inflammatory adipokines, such as tumor necrosis factor α (TNF-α), leptin, and chemerin. Recent studies have revealed that chemerin plays an important role in modulating physiologic as well as pathophysiologic processes. For example, chemerin stimulates maturation and differentiation of pre-adipocytes, acts as a chemoattractant and facilitates innate and acquired immunity. Furthermore, chemerin participates in the early stage of acute inflammation by reacting with the ChemR23 receptor. In various inflammatory diseases, the serum chemerin is significantly increased. Additionally, chemerin is also considered as an important biomarker for benign and malignant tumors. Thus, elucidating the pathologic mechanisms of chemerin action may facilitate the development of new therapeutic modalities to treat diverse inflammatory diseases. In this review, we summarize current knowledge of chemerin and its role as an important regulator in modulating various inflammatory diseases. Mechanisms underlying chemerin function in diverse diseases are explored to better understand its biochemistry and mechanisms of action.

The Potential Role of Chemerin, Lipocalin 2, and Apelin in the Diagnosis and Pathophysiology of Gestational Diabetes Mellitus

The exact role of adipokines in the pathogenesis of gestational diabetes mellitus (GDM) still remains not fully clear, and multiple studies have analyzed their potential contribution to the pathophysiology of this pregnancy complication. This study is aimed at evaluating serum chemerin, lipocalin 2, and apelin concentrations in GDM and healthy pregnant patients, assessing the correlation between these adipokines, and suggesting the potential role of these cytokines in the diagnosis and pathophysiology of GDM. The study comprised 237 pregnant women: 153 with GDM and 84 with physiological pregnancy. Serum concentrations of chemerin, lipocalin 2, and apelin were obtained at 24-29 weeks of gestation. The mean concentrations of chemerin and lipocalin 2 were significantly higher in the GDM group. The concentration of apelin was slightly higher in the GDM group, but not statistically significant. The strong positive correlation between chemerin and lipocalin 2 concentrations was noticed in both groups. Our data suggest that maternal chemerin and lipocalin 2 may play a significant role in the pathophysiology of GDM. We imply that these adipokines could potentially be established as novel biomarkers for the early identification of GDM. However, more studies are needed to analyze the effect of these adipokines on glucose metabolism during early pregnancy.

Measurement of Serum Chemerin, Oxidized LDL, and Vitamin D Levels in Prader–Willi Syndrome: A Cross-Sectional Study in Pediatric Egyptian Patients

Prader–Willi syndrome (PWS) is the commonest genetic cause of obesity. Oxidative stress and chronic low-grade inflammation play a crucial role in the pathogenesis of obesity. Alterations of vitamin D (25-OHD) levels are commonly encountered with obesity. The aim of this study was to analyze serum chemerin, oxidized low-density lipoprotein (ox-LDL), and 25-OHD values in pediatric PWS patients in comparison with obese healthy children and nonobese control groups, highlighting possible correlations with body mass index (BMI) and obesity. Twenty-six PWS Egyptian patients and 26 obese healthy individuals referred to the outpatient clinic of the Clinical Genetics Department, National Research Centre, Cairo, Egypt, and 20 control patients with matching age and sex were enrolled in the study. Patients were clinically diagnosed and confirmed by routine cytogenetic and fluorescence in-situ hybridization analysis. Anthropometric measurements were performed, and BMI was calculated by weight/height2 (kg/m2), and BMI z score was also determined. Serum chemerin, ox-LDL, and vitamin D were determined by enzyme-linked immunosorbent assay. Chemerin levels, which reflected chronic inflammation, were significantly elevated as compared with obese and nonobese controls (p ≤ 0.0001). Concerning oxidative damage, children with PWS showed higher Ox-LDL levels compared with obese and nonobese controls (p < 0.0001). Vitamin D levels were significantly lower in PWS patients compared with obese and nonobese controls (p ≤ 0.0001). Our data showed that obesity in PWS is associated with oxidative stress and chronic low-grade inflammation. Ox-LDL is a good indicator of oxidative stress, and chemerin could be used as a biomarker for the chronic inflammatory state. Furthermore, vitamin D supplementation is recommended in PWS patients

Adipokines: New Potential Therapeutic Target for Obesity and Metabolic, Rheumatic, and Cardiovascular Diseases

Besides its role as an energy storage organ, adipose tissue can be viewed as a dynamic and complex endocrine organ, which produces and secretes several adipokines, including hormones, cytokines, extracellular matrix (ECM) proteins, and growth and vasoactive factors. A wide body of evidence showed that adipokines play a critical role in various biological and physiological functions, among which feeding modulation, inflammatory and immune function, glucose and lipid metabolism, and blood pressure control. The aim of this review is to summarize the effects of several adipokines, including leptin, diponectin, resistin, chemerin, lipocalin-2 (LCN2), vaspin, omentin, follistatin-like 1 (FSTL1), secreted protein acidic and rich in cysteine (SPARC), secreted frizzled-related protein 5 (SFRP5), C1q/TNF-related proteins (CTRPs), family with sequence similarity to 19 member A5 (FAM19A5), wingless-type inducible signaling pathway protein-1 (WISP1), progranulin (PGRN), nesfatin-1 (nesfatin), visfatin/PBEF/NAMPT, apelin, retinol binding protein 4 (RPB4), and plasminogen activator inhibitor-1 (PAI-1) in the regulation of insulin resistance and vascular function, as well as many aspects of inflammation and immunity and their potential role in managing obesity-associated diseases, including metabolic, osteoarticular, and cardiovascular diseases.

Diabetes and Obesity-Cumulative or Complementary Effects On Adipokines, Inflammation, and Insulin Resistance

Background: Diabetes and obesity are increasingly significant public health issues. The aim of this study was to evaluate the relationship between adipocytokines (leptin, ghrelin, and chemerin), inflammation (sVCAM1—soluble vascular adhesion molecule 1, sICAM1—soluble intercellular adhesion molecule 1), and insulin resistance in the presence of obesity and diabetes mellitus. Methods: 88 subjects, with a mean age of 61.96 ± 10.15 years, 75% of whom were women, were evaluated (in order to consider different associations between obesity and diabetes, subjects were categorized into four groups). Results: Overall, we found significant correlations between sICAM1-sVCAM1 rho = 0.426 and ghrelin-chemerin rho = −0.224. In the obesity + diabetes group, leptin correlated with sICAM1 rho = 0.786, and sVCAM1 negatively with glycemia/insulin rho = −0.85. Significant differences were found between the groups regarding sVCAM1 (p = 0.0134), leptin (p = 0.0265) and all insulin resistance scores, with differences influenced by the subjects’ gender. In conclusion, although there are currently many unknown aspects of the release and the role of various adipokines, in particular chemerin, its implication in early glucose metabolism dysregulation disorders seems very likely.

Association of Serum Omentin-1, Chemerin, and Leptin with Acute Myocardial Infarction and its Risk Factors

Objective:

To determine the association of serum omentin-1, chemerin, and leptin with acute myocardial infarction (AMI) and its risk factors among individuals admitted with AMI to the coronary care unit (CCU).

Methods:

The current case-control study was conducted at the CCU of King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia (KSA), in 2016-2018. A total of 122 AMI patients admitted to CCU, and 52 BMI and age-matched healthy subjects, between 30 and 65 years of age, were included.

Results:

Chemerin and omentin-1 are independent predictors of the incidence of MI. Furthermore, serum omentin-1 was significantly lowered while chemerin and hsCRP levels were found to be significantly raised among the individuals with AMI compared to the healthy subjects, and no notable change was found in the serum leptin level. Serum omentin-1, chemerin, and leptin were significantly correlated with weight, BMI, waist circumference in patients, and control subjects. Binary logistic regression analysis displayed that the occurrence of MI is positively correlated with fasting plasma glucose (FPG), TC, TG, LDL-C, hsCRP, and chemerin and in a negative manner with HDL-C, and omentin. The chemerin and omentin-1 were also linked with the MI in multiple logistic regression analysis.

Conclusions:

The present results indicated that the serum omentin levels were significantly lowered while chemerin and hsCRP levels were found to be markedly raised among patients. No change was found in serum leptin levels. Serum chemerin and omentin-1 levels were independently associated with the MI. It appears that these parameters may be used to assess the risk spectrum of CAD.

Chemerin concentrations in infants born small for gestational age: correlations with triglycerides and parameters related to glucose homeostasis

Infants born small for gestational age (SGA) are known to have increased risk of developing several pathologies, including the metabolic syndrome, when they grow up. It has been described that both the growth pattern of these children as well as the risk of their presenting future metabolic disorders can be influenced by the expression of adipokines. Among them, chemerin has demonstrated to be implicated in lipid and glucose metabolism, presenting higher circulating concentration in diabetic and obese subjects. Thus, the aim of this study was to analyze the association of anthropometric parameters and plasmatic biochemical parameters with circulating chemerin concentration in SGA children. This prospective, longitudinal study was carried out in plasma samples of Caucasian children born SGA at Hospital Universitario de Álava-Txagorritxu. Significant positive correlations were observed between chemerin concentrations at 3 months and insulin values at 3 months and also with triglyceride levels at 24 months. These associations were maintained after adjustment by anthropometric parameters. Therefore, we suggest that circulating chemerin concentration, measured at an early age, might be an indicator of future metabolic alterations in SGA children.

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.

Plasma levels of adiponectin and chemerin are associated with early stage of atherosclerosis in older adults with type 2 diabetes mellitus

OBJECTIVE

Adipokines, such as adiponectin and chemerin, regulate fat metabolism and are critical for the development of atherosclerosis. Investigating the correlations of adiponectin and chemerin with atherosclerosis in older adults with type 2 diabetes mellitus (T2DM) will shed light on the search for new markers for early diagnosis of diabetic atherosclerosis.

METHODS

A total of 120 older T2DM patients and nine healthy controls were enrolled in this study. The clinical parameters, such as brachial-ankle pulse wave velocity (ba-PWV), adiponectin, and chemerin, were examined and recorded. T2DM subjects were divided into three groups according to ba-PWV level (high, medium, or low). The data were processed and analyzed by identical methods.

RESULTS

Significantly higher chemerin and lower adiponectin levels were detected in the plasma of T2DM patients than in healthy controls. The plasma levels of chemerin and adiponectin were negatively correlated in T2DM patients. Moreover, chemerin and adiponectin were significantly correlated with body mass index, ankle-brachial index, insulin, and ba-PWV. Multiple linear regression analysis revealed that chemerin and adiponectin were independently affecting ba-PWV.

CONCLUSION

Adiponectin and chemerin are potential markers for diagnosis and monitoring of early stage of atherosclerosis in older adults with T2DM. Further clinical investigations are required to confirm these markers.

Alzheimer's disease-associated (hydroxy)methylomic changes in the brain and blood

BACKGROUND

Late-onset Alzheimer's disease (AD) is a complex multifactorial affliction, the pathogenesis of which is thought to involve gene-environment interactions that might be captured in the epigenome. The present study investigated epigenome-wide patterns of DNA methylation (5-methylcytosine, 5mC) and hydroxymethylation (5-hydroxymethylcytosine, 5hmC), as well as the abundance of unmodified cytosine (UC), in relation to AD.

RESULTS

We identified epigenetic differences in AD patients (n = 45) as compared to age-matched controls (n = 35) in the middle temporal gyrus, pertaining to genomic regions close to or overlapping with genes such as OXT (- 3.76% 5mC, pŠidák = 1.07E-06), CHRNB1 (+ 1.46% 5hmC, pŠidák = 4.01E-04), RHBDF2 (- 3.45% UC, pŠidák = 4.85E-06), and C3 (- 1.20% UC, pŠidák = 1.57E-03). In parallel, in an independent cohort, we compared the blood methylome of converters to AD dementia (n = 54) and non-converters (n = 42), at a preclinical stage. DNA methylation in the same region of the OXT promoter as found in the brain was found to be associated with subsequent conversion to AD dementia in the blood of elderly, non-demented individuals (+ 3.43% 5mC, pŠidák = 7.14E-04).

CONCLUSIONS

The implication of genome-wide significant differential methylation of OXT, encoding oxytocin, in two independent cohorts indicates it is a promising target for future studies on early biomarkers and novel therapeutic strategies in AD.

Chemerin-induced macrophages pyroptosis in fetal brain tissue leads to cognitive disorder in offspring of diabetic dams

BACKGROUND

Chemerin is highly expressed in the serum, placenta tissue, and umbilical cord blood of diabetic mother; however, the impact of chemerin on cognitive disorders of offspring from mothers with diabetes in pregnancy remains unclear.

METHODS

A diabetic phenotype in pregnant mice dams was induced by streptozocin (STZ) injection or intraperitoneal injection of chemerin. Behavioral changes in offspring of diabetic dams and nondiabetic controls were assessed, and changes in chemerin, two receptors of chemerin [chemerin receptor 23 (ChemR23) and chemokine (C-C motif) receptor-like 2 (CCRL2)], macrophages, and neurons in the brain tissue were studied to reveal the underlying mechanism of the behavioral changes.

RESULTS

Chemerin treatment mimicked the STZ-induced symptom of maternal diabetes in mice along with the altered behavior of offspring in the open field test (OFT) assay. In the exploring process for potential mechanism, the brain tissues of offspring from chemerin-treated dams were observed with an increase level of macrophage infiltration and a decrease number of neuron cells. Moreover, an increased level of NOD-like receptor family pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like (Asc) protein as well as pyroptosis [characterized by increased active caspase-1 content and secretion of cytokines such as interleukin (IL) 1 beta (IL-1β) and IL-18] more activated in macrophages is also observed in the brain of these diabetic dam's offspring, in the presence of ChemR23. In vitro, it was found that pyroptosis activation was increased in macrophages separated from the abdominal cavity of normal mice, after chemerin treatment. However, depletion of CCRL2 decreased the level of chemerin in the brain tissues of diabetic dams' offspring; depletion of ChemR23 decreased macrophage pyroptosis, and depletion of either receptor reversed chemerin-mediated neurodevelopmental deficits and cognitive impairment of offspring of diabetic pregnant dams.

CONCLUSIONS

Chemerin induced diabetic pregnant disease and CCRL2 were required to enrich chemerin in the brain of offspring. Aggregation of chemerin could lead to macrophage recruitment, activation of pyroptosis, the release of inflammatory cytokines, a decrease in the number of neurons, and cognitive impairment in offspring in a ChemR23-dependent manner. Targeting CCRL2 and/or ChemR23 could be useful for treating neuropsychological deficits in offspring of dams with diabetes in pregnancy.

Serum Chemerin as a Novel Prognostic Indicator in Chronic Heart Failure

Background It has been documented that circulating chemerin is associated with inflammation, metabolic syndrome, and coronary artery disease. The present study was aimed to evaluate the prognostic value of serum chemerin in patients with chronic heart failure. Methods and Results We included 834 patients with chronic heart failure in a prospective cohort study and investigated the association between serum chemerin and clinical outcomes using multivariate Cox regression analysis. Patients with higher chemerin levels tended to be older and women and were more likely to experience hypertension, diabetes mellitus, and hyperlipemia. Cox regression analysis showed that chemerin was a significant predictor of major adverse cardiac events (hazard ratio, 1.83; 95% CI, 1.31-2.96) after adjustment for conventional risk factors. Net reclassification and integrated discrimination improvements for major adverse cardiac events were markedly improved by addition of chemerin to the reference model. In addition, chemerin was an independent predictor of all-cause mortality (hazard ratio, 1.67; 95% CI, 1.21-2.73) after multivariable adjustment. Furthermore, the Kaplan-Meier survival analysis revealed that chemerin was a prognostic indicator of major adverse cardiac events in patients with chronic heart failure and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels above and below the median. Conclusions Our study suggests that chemerin is a novel serum marker for predicting major adverse cardiac events in patients with chronic heart failure.

Chemerin Isoforms and Activity in Obesity

Overweight and adiposity are risk factors for several diseases, like type 2 diabetes and cancer. White adipose tissue is a major source for adipokines, comprising a diverse group of proteins exerting various functions. Chemerin is one of these proteins whose systemic levels are increased in obesity. Chemerin is involved in different physiological and pathophysiological processes and it regulates adipogenesis, insulin sensitivity, and immune response, suggesting a vital role in metabolic health. The majority of serum chemerin is biologically inert. Different proteases are involved in the C-terminal processing of chemerin and generate diverse isoforms that vary in their activity. Distribution of chemerin variants was analyzed in adipose tissues and plasma of lean and obese humans and mice. The Tango bioassay, which is suitable to monitor the activation of the beta-arrestin 2 pathway, was used to determine the ex-vivo activation of chemerin receptors by systemic chemerin. Further, the expression of the chemerin receptors was analyzed in adipose tissue, liver, and skeletal muscle. Present investigations assume that increased systemic chemerin in human obesity is not accompanied by higher biologic activity. More research is needed to fully understand the pathways that control chemerin processing and chemerin signaling.

Chemerin rs17173608 and vaspin rs2236242 gene variants on the risk of end stage renal disease (ESRD) and correlation with plasma malondialdehyde (MDA) level

Introduction: End-stage renal disease (ESRD) is associated with critical kidney illness that seriously affects the lifespan. Genetic factors and oxidative stress could play critical role in the development of ESRD. We assessed the association between chemerin rs17173608 T/G and vaspin rs2236242 T/A genes variants with the risk of ESRD and their correlation with plasma malondialdehyde (MDA) level.

Materials and methods: In a case-control study, 131 gender and age-matched unrelated healthy controls and 110 ESRD patients were enrolled. The chemerin rs17173608 T/G and vaspin rs2236242 T/A were detected by Tetra primer-amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). The MDA concentration was determined by HPLC.

Results: Our findings for the first time revealed that in codominant genetic model (T/G vs. T/T genotype), the T/G genotype of chemerin gene significantly had a protective role against ESRD susceptibility. Also, in the presence of chemerin G allele, the risk of ESRD decreased by 0.79-fold (p = .048) in Kurdish population of Iran. The MDA serum levels in ESRD patients carrying the chemerin T/G + G/G genotype of rs17173608 T/G and also in carriers of A/A + T/A genotype of vaspin rs2236242 T/A were significantly higher compared to those in control subjects. The overall distribution of vaspin rs2236242 T/A genotypes and alleles comparing ESRD patients and healthy subjects were not statistically significant.

Conclusion: We found that the G allele of chemerin rs17173608 compared to T allele decreased the risk of ESRD, and there was a significant association between chemerin and vaspin variants with plasma MDA level in a sample of the Iranian population.

Circulating chemerin levels and gestational diabetes mellitus: a systematic review and meta-analysis

Background

Chemerin is a novel adipokine which is associated with metabolic syndrome and type 2 diabetes mellitus. However, recent investigations regarding circulating chemerin levels in gestational diabetes mellitus (GDM) are conflicting. This meta-analysis is to evaluate and determine their associations.

Methods

A systematic literature search was performed in PubMed, EMBASE and Web of Science up to 13 December 2017. Pooled standardized mean differences (SMD) and 95% confidence interval (CI) were calculated using a random-effect model.

Results

Eleven studies comprising 742 GDM patients and 840 normal pregnant women were included. Circulating chemerin levels were increased in GDM patients compared with healthy pregnant women (SMD: 1.16; 95% CI: 0.29, 2.04; P = 0.009). Subgroup analyses revealed such difference was especially available in the groups of the second trimester (SMD: 1.47; 95% CI: 0.28, 2.67) and mean age < 30 years (SMD: 2.30; 95% CI: 0.69, 3.91) of GDM patients. There was significant heterogeneity among studies (I² = 98.0%, P < 0.001); however, heterogeneity disappeared or markedly decreased in the subgroups of European populations (I² = 0.0%, P = 0.531), age ≥ 30 years (I² = 28.2%, P = 0.223) and WHO diagnostic criteria (I² = 0.0%, P = 0.490) when stratifying by study location, trimester of chemerin measurement and the diagnostic criteria of GDM.

Conclusions

The elevated levels of circulating chemerin were associated with GDM, which suggests it might play an important role in the pathogenetic mechanism of GDM.

Chemerin is elevated in multiple myeloma patients and is expressed by stromal cells and pre-adipocytes

Chemerin is a recently discovered adipokine shown to be involved in both inflammatory and metabolic processes. Here, we demonstrate that chemerin serum levels are elevated in patients with multiple myeloma and that it increases with disease progression. We found that chemerin is expressed by stromal cells and preadipocytes, whereas its receptor CCRL2 is expressed by primary myeloma cells, suggesting a paracrine signaling loop between bone marrow stromal cells/adipocytes and myeloma cells. This is the first study exploring chemerin and its receptors in multiple myeloma.

Is Chemerin associated with gestational diabetes mellitus? An evidence-based clinical research from Chinese women

The present study aimed to explore the association between gestational diabetes mellitus (GDM) and Chemerin, by analysing Chemerin level, clinical data and biochemical parameters among 46 GDM patients and 43 controls. It was found that the Chemerin levels from cord blood, peripheral blood, adipose tissue and placenta tissue were all significantly higher in the GDM group than those in the control group (p < .05 for all). Maternal insulin resistance (IR) index and serum inflammation parameters, including C-reactive protein and white blood cells, were also higher in GDM group (p < .05 for all). Moreover, maternal IR index and circulating insulin level were both positively correlated with maternal circulating Chemerin level (p < .05 for both). Our findings suggest that Chemerin, associated with IR and more expressed in GDM women, might participate in the pathogenesis of GDM. Impact Statement What is already known on this subject: Chemerin, a recently-discovered adipocytokine, has been widely-considered to be involved in metabolic diseases, and several studies have investigated it in gestational diabetes mellitus (GDM), but with no consensus about the level comparison between GDM and controls. What the results of this study add: The present case-control study found that the levels of Chemerin from cord blood, peripheral blood, adipose tissue and placenta tissue were all significantly higher in the GDM group. What the implications are of these findings for clinical practice and/or further research: Also, the circulating Chemerin level was positively correlated with insulin index, which we thought would add to the evidence that Chemerin does be associated with GDM, contributing to elucidating the pathogenesis of GDM.

CHEMERIN AND FACTORS RELATED TO CARDIOVASCULAR RISK IN CHILDREN AND ADOLESCENTS: A SYSTEMATIC REVIEW

OBJECTIVE

To review findings on chemerin and factors related to cardiovascular risk in children and adolescents.

DATA SOURCE

A systematic review was performed, according to the standards proposed by the PRISMA guideline, on PubMed, Science Direct, and Lilacs databases. The descriptor "chemerin" was used in combination with "children" and "adolescent", no time limit applied. The research encompassed only original articles written in English, conducted with human subjects - the adult and elderly populations excluded -, as well as literature reviews, brief communications, letters, and editorials.

DATA SYNTHESIS

After independent analyses of the studies by two reviewers, seven articles meeting the eligibility criteria, published between 2012 and 2016, remained for the review. Cross-sectional, prospective, cohort, and case-control studies were included. The importance of chemerin adipokines on the risk factors for cardiovascular disease is demonstrated by its association with obesity and diabetes mellitus, as well as clinical, anthropometric, and biochemical parameters. However, the strength of evidence from these studies is relatively low, due to their heterogeneity, with several limitations such as small samples and consequent lack of representativeness, lack of standardization in dosage methods, cross-sectional design of most studies, and impossibility of extrapolating results.

CONCLUSIONS

The deregulation of chemerin caused by increased adipose tissue may contribute to the development of cardiovascular diseases, suggesting that this adipokine may play a significant role in early identification of individuals at risk.

International Union of Basic and Clinical Pharmacology CIII: Chemerin Receptors CMKLR1 (Chemerin1) and GPR1 (Chemerin2) Nomenclature, Pharmacology, and Function

Chemerin, a chemoattractant protein and adipokine, has been identified as the endogenous ligand for a G protein-coupled receptor encoded by the gene CMKLR1 (also known as ChemR23), and as a consequence the receptor protein was renamed the chemerin receptor in 2013. Since then, chemerin has been identified as the endogenous ligand for a second G protein-coupled receptor, encoded by the gene GPR1 Therefore, the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification recommends that the official name of the receptor protein for chemokine-like receptor 1 (CMKLR1) is chemerin receptor 1, and G protein-coupled receptor 1 is chemerin receptor 2 to follow the convention of naming the receptor protein after the endogenous ligand. Chemerin receptor 1 and chemerin receptor 2 can be abbreviated to Chemerin1 and Chemerin2, respectively. Chemerin requires C-terminal processing for activity, and human chemerin21-157 is reported to be the most active form, with peptide fragments derived from the C terminus biologically active at both receptors. Small-molecule antagonist, CCX832, selectively blocks CMKLR1, and resolvin E1 activation of CMKLR1 is discussed. Activation of both receptors by chemerin is via coupling to Gi/o, causing inhibition of adenylyl cyclase and increased Ca2+ flux. Receptors and ligand are widely expressed in humans, rats, and mice, and both receptors share ∼80% identity across these species. CMKLR1 knockout mice highlight the role of this receptor in inflammation and obesity, and similarly, GPR1 knockout mice exhibit glucose intolerance. In addition, the chemerin receptors have been implicated in cardiovascular disease, cancer, steroidogenesis, human immunodeficiency virus replication, and neurogenerative disease.

Molecular subtyping of Treponema pallidum and associated factors of serofast status in early syphilis patients: Identified novel genotype and cytokine marker

Serofast, a persistent nontreponemal serological response observed in early syphilis patients after conventional treatment, remains a concern of clinicians and syphilis patients. No consensus has been established, however, that defines an effective treatment strategy and clarifies the pathogenesis. In this study, 517 patients with early syphilis were enrolled and treated. Twelve months after treatment, 79.3% (410/517) of patients achieved serological cure, 20.1% (104/517) were serofast, and 0.6% (3/517) were serological failures. Multivariate analysis demonstrated that older age (>40 years) and lower baseline RPR titer (≤ 1:8) were associated with serofast status. We also identified 21 T. pallidum molecular subtypes among early syphilis patients and detected a new subtype, 14i/a. We found that the proportion of 14i/a type in serofast patients was significantly higher than that in patients with serological cure, predicting an increasing risk of serofast status. Levels of chemerin were higher in the serum of serofast cases than serological cure cases, potentially indicating a novel cytokine marker for serofast in early syphilis patients after therapy. We hope that these results contribute to improve guidelines for the management of syphilis patients who experience serofast.

Impact of selective LDL apheresis on serum chemerin levels in patients with hypercholesterolemia

Background

Selective low-density lipoprotein (LDL) apheresis is commonly used to treat patients with familial hypercholesterolemia (FH). Chemerin is an adipokine with putative roles in the regulation of lipid metabolism.

Methods

In our pilot study, we measured serum chemerin levels by enzyme-linked immunosorbent assay in six severe heterozygous FH patients before and after their first LDL apheresis treatments using the technique of direct adsorption of lipoproteins (DALI).

Results

The first treatment sessions decreased serum chemerin levels by an average of 27.26 %. While following one patient, 12 months of regular LDL apheresis resulted in a permanent reduction in his serum chemerin level. Changes in the lipoprotein subfractions measured by gel electrophoresis (Lipoprint) correlated with the reduction of chemerin levels. Furthermore, we eluted and then measured chemerin bound to the DALI column.

Conclusion

We conclude that LDL apheresis decreases the circulating level of chemerin by binding the protein to the column and thus improves lipoprotein subfraction pattern.

Association of chemerin levels and bone mineral density in Chinese obese postmenopausal women

Increasing evidence suggests the association between obesity and bone metabolism. However, whether excessive fat accumulation has a beneficial or adverse effect on bone health remains controversial. Chemerin is a novel adipocyte-derived hormone and a chemoattractant cytokine that regulates adipogenesis. This study was performed to investigate the associations of serum chemerin with bone mineral density (BMD) and serum pro-inflammatory cytokine levels in 543 Chinese obese postmenopausal women. BMD of the femoral neck and lumbar spine, lean mass, and fat mass were measured using dual energy X-ray absorptiometry. Anthropometric assessment and laboratory measurements were performed. The age, time after menopause, and fat mass were negatively correlated with femoral and lumbar BMD, whereas lean mass was positively correlated with aforementioned variables. Furthermore, BMD at the lumbar spine was inversely associated with serum chemerin and TNF-α levels (r = -0.155, P = 0.001; r = -0.147, P = 0.001). Multiple linear regression analyses showed that serum chemerin levels were negatively correlated with BMD at the lumbar site after controlling for the age, lean, and fat mass (β = -0.125, P = 0.001). Chronic low-grade inflammation state in obese population has an inverse effect on bone mass. Chemerin as an adipocytokine and chemoattractant negatively affects the bone mass of Chinese obese postmenopausal women. Further studies are needed to confirm the potential role of chemerin in the crosstalk between bone and fat accumulation in obese population.

The role of GPR1 signaling in mice corpus luteum

Chemerin, a chemokine, plays important roles in immune responses, inflammation, adipogenesis, and carbohydrate metabolism. Our recent research has shown that chemerin has an inhibitory effect on hormone secretion from the testis and ovary. However, whether G protein-coupled receptor 1 (GPR1), the active receptor for chemerin, regulates steroidogenesis and luteolysis in the corpus luteum is still unknown. In this study, we established a pregnant mare serum gonadotropin-human chorionic gonadotropin (PMSG-hCG) superovulation model, a prostaglandin F2α (PGF2α) luteolysis model, and follicle and corpus luteum culture models to analyze the role of chemerin signaling through GPR1 in the synthesis and secretion of gonadal hormones during follicular/luteal development and luteolysis. Our results, for the first time, show that chemerin and GPR1 are both differentially expressed in the ovary over the course of the estrous cycle, with highest levels in estrus and metestrus. GPR1 has been localized to granulosa cells, cumulus cells, and the corpus luteum by immunohistochemistry (IHC). In vitro, we found that chemerin suppresses hCG-induced progesterone production in cultured follicle and corpus luteum and that this effect is attenuated significantly by anti-GPR1 MAB treatment. Furthermore, when the phosphoinositide 3-kinase (PI3K) pathway was blocked, the attenuating effect of GPR1 MAB was abrogated. Interestingly, PGF2α induces luteolysis through activation of caspase-3, leading to a reduction in progesterone secretion. Treatment with GPR1 MAB blocked the PGF2α effect on caspase-3 expression and progesterone secretion. This study indicates that chemerin/GPR1 signaling directly or indirectly regulates progesterone synthesis and secretion during the processes of follicular development, corpus luteum formation, and PGF2α-induced luteolysis.

A neuroendocrine role for chemerin in hypothalamic remodelling and photoperiodic control of energy balance

Long-term and reversible changes in body weight are typical of seasonal animals. Thyroid hormone (TH) and retinoic acid (RA) within the tanycytes and ependymal cells of the hypothalamus have been implicated in the photoperiodic response. We investigated signalling downstream of RA and how this links to the control of body weight and food intake in photoperiodic F344 rats. Chemerin, an inflammatory chemokine, with a known role in energy metabolism, was identified as a target of RA. Gene expression of chemerin (Rarres2) and its receptors were localised within the tanycytes and ependymal cells, with higher expression under long (LD) versus short (SD) photoperiod, pointing to a physiological role. The SD to LD transition (increased food intake) was mimicked by 2 weeks of ICV infusion of chemerin into rats. Chemerin also increased expression of the cytoskeletal protein vimentin, implicating hypothalamic remodelling in this response. By contrast, acute ICV bolus injection of chemerin on a 12 h:12 h photoperiod inhibited food intake and decreased body weight with associated changes in hypothalamic neuropeptides involved in growth and feeding after 24 hr. We describe the hypothalamic ventricular zone as a key site of neuroendocrine regulation, where the inflammatory signal, chemerin, links TH and RA signaling to hypothalamic remodeling.

Serum and salivary levels of chemerin and MMP-9 in oral squamous cell carcinoma and oral premalignant lesions

OBJECTIVE

The objective of this study was to investigate serum and salivary levels of chemerin and MMP-9 as early diagnostic biomarkers for patients with oral premalignant lesions (OPMLs) and oral squamous cell carcinoma (OSCC).

METHODS

This study included 45 individuals; 15 healthy control, 15 patients with OPMLs, and 15 patients with early stage OSCC. Chemerin and MMP-9 were determined in serum and saliva samples utilizing enzyme-linked immunosorbent assays.

RESULTS

Serum and salivary levels of chemerin and MMP-9 in patients with OSCC were significantly higher than OPMLs and control group. Patients with OPMLs showed also elevated profiles for serum and salivary chemerin and MMP-9 compared to control group. Receiver operator characteristic curve analysis revealed that all tested biomarkers have 100 % sensitivity and 100 % specificity with area under the curve (AUC) of 1.00 in detecting early stage OSCC and OPMLs. In distinguishing OSCC from OPMLs, salivary MMP-9, serum chemerin, and salivary chemerin showed AUC of 0.99, 0.92, and 0.88, respectively, showing higher sensitivity and specificity compared with serum MMP-9 (AUC; 0.6) which failed to differentiate between the two conditions.

CONCLUSION

Chemerin and MMP-9 might be considered as salivary diagnostic biomarkers for OPMLs and early detection of OSCC and also for detecting early cancerization of OPMLs.

CLINICAL RELEVANCE

This research implied that salivary chemerin was a novel diagnostic factor for patients with OPML and early stage OSCC patients, and chemerin could be a new therapeutic target for regulating cancer angiogenesis and blocking malignization of OPMLs.

Prenatal and Childhood Growth, Chemerin Concentrations, and Metabolic Health in Adult Life

Several noncommunicable diseases have their origins in early developmental phases. One factor possibly explaining the association between early growth and later health could be adipocyte function. The objective of this study was to assess the association between the adipocytokine chemerin and early growth and later health. 1074 participants from Helsinki Birth Cohort Study born 1934-1944 with information on prenatal and childhood growth participated. Metabolic outcomes include glucose tolerance, adiposity, and chemerin concentration. Mean chemerin concentrations were 5.0 ng/mL higher in women than in men (95% CI 2.7 to 7.2, p < 0.001). The strongest correlate of chemerin concentration was adult waist circumference and body fat percentage (r = 0.22, p < 0.001 and r = 0.21, p < 0.001, resp.). After adjustment for body fat percentage, chemerin concentration was 5.4 ng/mL lower in subjects with type 2 diabetes than in those with normal glucose tolerance (-0.2 to 10.9, p = 0.06). It was 3.0 ng/mL higher in those with metabolic syndrome than in those without (0.6 to 5.3, p = 0.01). No measure of early growth was associated with chemerin concentration. Our findings do not support a role for chemerin in linking early growth with later metabolic health.

A preliminary candidate approach identifies the combination of chemerin, fetuin-A, and fibroblast growth factors 19 and 21 as a potential biomarker panel of successful aging

Although the number of centenarians is growing worldwide, the potential factors influencing the aging process remain only partially elucidated. Researchers are increasingly focusing toward biomarkers as tools to shed more light on the pathophysiology of complex phenotypes, including the ability to reach successful aging, i.e., free of major chronic diseases. We therefore conducted a case-control study examining the potential associations of multiple candidate biomarkers in healthy centenarians and sex-matched healthy elderly controls. Using a case-control study of 81 centenarians (aged ≥ 100 years) selected based on the fact that they were disease-free and 46 healthy elderly controls (aged 70-80 years), serum levels of 15 different candidate biomarkers involved in the regulation of metabolism, angiogenesis, inflammation, and bone formation were measured. Of the 15 biomarkers tested, four molecules (chemerin, fetuin-A, and fibroblast growth factors [FGF] 19 and 21) were found to be independently associated with successful aging regardless of sex. Logistic regression analysis confirmed that chemerin, fetuin-A, FGF19, and FGF21 were independently associated with successful aging [predicted probability (PP) = 1 / [1 + 1 / exp (11.832 - 0.027 × (chemerin) - 0.009 × (fetuin-A) + 0.014 × (FGF19) - 0.007 × (FGF21)]. The area under the curve (AUC) of predicted probability values for the four-biomarker panel revealed that it can discriminate between centenarians and elderly controls with excellent accuracy (AUC > 0.94, P < 0.001). Although preliminary in essence and limited by the low sample size and lack of replication in other independent cohorts, our data suggest an independent association between successful aging and serum chemerin, fetuin-A, FGF19, and FGF21, which may provide novel information on the mechanisms behind the human aging process. Whether the four-biomarker panel may predict successful aging deserves further scrutiny.