Chemerin Expression Research Articles

Effect of the leukocyte chemoattractant chemerin on PTEN via CMKLR1 in human prostate cancer.

282 Background: Recent data in preclinical models has shown that phosphatase and tensin homolog (PTEN) loss correlated with decreased tumor immune cell infiltration as well as decreased response to T cell-based immunotherapy. Chemerin ( RARRES2) is a recently identified endogenous leukocyte chemoattractant shown to recruit innate immune cells through its G-protein coupled receptor CMKLR1. RARRES2 is commonly downregulated in prostate and other cancers (eg sarcoma) compared to their normal tissue counterparts. Our previous preclinical studies showed that forced overexpression of chemerin in tumors was capable of recruiting immune effector cells into the tumor microenvironment and suppressing tumor growth. Methods: Here, we investigate the effects of chemerin on tumor cell intrinsic processes by exposing prostate and sarcoma tumor lines to exogenous recombinant chemerin in vitro. Evaluation of PTEN was performed at both the mRNA and protein levels, using both quantitative PCR as well as Western blotting. PTEN immunoprecipitation by and Malachite Green assays were used to determine PTEN activity. In vitro invasion assays were performed to investigate the functional impact of chemerin exposure on tumor intrinsic activity. Knockdown of CMKLR1 using siRNA was performed to determine its role in tumor response. Results: Using both prostate and sarcoma tumor lines, we found exogenous chemerin was able to significantly upregulate PTEN expression at both the mRNA and protein levels in a dose-dependent manner. PTEN phosphatase activity was also significantly increased by chemerin. Exposure to chemerin did not result in increased apoptosis or altered in vitro proliferation. Importantly, chemerin treatment significantly decreased in vitro tumor invasion. Knockdown of CMKLR1 resulted in loss of chemerin-induced PTEN and PTEN activity and restored tumor migration, suggesting a link between this GPCR and PTEN. Conclusions: For the first time to our knowledge, we have shown a link between chemerin and PTEN expression and activity in both prostate and sarcoma tumor lines. This work has potential clinical implications on both tumor cell intrinsic and extrinsic responses to chemerin-based immunotherapeutic strategies.

Expression of chemerin in the synovial fluid of patients with temporomandibular joint disorders.

The synovial membrane and fluid are significantly involved in the pathogenesis of temporomandibular joint (TMJ) disorders. This study aimed to investigate the relation between levels of chemerin in the synovial fluid (SF) of patients with TMJ disorder and their relationship. Sixty samples of SF were obtained from patients with an internal derangement (ID) or osteoarthritis (OA). Chemerin in the SF was examined by enzyme-linked immunosorbent assay (ELISA). The results showed greater levels of chemerin in the SF of patients with OA than ID. While chemerin levels were positively correlated with pain scores, they were inversely correlated with MMO. Chemerin levels increased progressively as the disorder stage became more severe. The findings of this study suggest that chemerin in SF may play role as a predisposing factor and may represent a novel potential prognostic biochemical marker in the pathogenesis of TMJ disorders.

Adipokine expression and endothelial function in subclinical hypothyroidism rats.

The purpose of our study was to observe adipokine expression and endothelial function in subclinical hypothyroidism (sHT) rats and to determine whether levothyroxine (LT4) treatment affects these changes. Sixty-five male Wistar rats were randomly divided into five groups: the control group; sHT A, B and C groups and the sHT + T4 group. The sHT rats were induced by methimazole (MMI) and the sHT + T4 rats were administered LT4 treatment after 8 weeks of MMI administration. Thyroid function and lipid levels were measured using radioimmunoassays and enzymatic colorimetric methods, respectively. Serum adiponectin (APN), chemerin, TNF-α, endothelin (ET-1) and nitric oxide (NO) levels were measured using ELISA kits and a nitric-reductive assay. The expression of APN, chemerin and TNF-α in visceral adipose tissue (VAT) was measured in experimental rats using RT-PCR and Western blotting. Hematoxylin–eosin (HE) staining was used to observe changes in adipose tissue. The sHT rats had significantly higher levels of thyroid-stimulating hormone (TSH), TNF-α, chemerin, ET-1, total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and lower levels of APN and NO than those in control and sHT + T4 rats. Based on Pearson correlation analysis, the levels of chemerin, TNF-α, ET-1, LDL-C, TC and triglyceride (TG) were positively correlated with TSH, but APN and NO levels were negatively correlated with TSH. These findings demonstrated that high TSH levels contribute to the changes of adipokines and endothelial dysfunction in sHT, but LT4 treatment ameliorates those changes.

The Change of Left Ventricular Function in Rats with Subclinical Hypothyroid and the Effects of Thyroxine Replacement.

Objective The main purpose of this study was to explore the relationships between serca2a, Ryr2, adipokines, and the left ventricular function in the subclinical hypothyroidism with different TSH levels and to determine the impact of L-T4 treatment on these indexes. Methods Sixty-five male Wistar rats were randomly divided into five groups: control group; sHT A, B, and C group; and sHT + T4 group. The sHT rats were induced by methimazole (MMI), and the sHT + T4 rats were administered with L-T4 treatment after 8 weeks of MMI administration. Serum TT4, TSH, APN, chemerin, and TNF-α were detected by radioimmunoassay kits and ELISA kits; left ventricular function was measured by PowerLab system via subclavian artery catheter. The expression of Serca2a, Ryr2, APN, chemerin, and TNF-α were detected by RT-PCR, Western blot, and immunohistochemistry. Results The sHT groups had significantly higher TSH, chemerin, and TNF-α and lower Serca2a, Ryr2, and APN. The left ventricular pressure and heart rate in sHT groups were significantly lower in control and sHT + T4 group. Histopathological examination revealed the pathological changes in the sHT rats' heart. L-T4 administration reduced TSH level and improved left ventricular function. Conclusions TSH can impair left ventricular function by regulating several factors, and L-T4 treatment ameliorates it in sHT rats.

Elevated Chemerin Induces Insulin Resistance in Human Granulosa-Lutein Cells from Polycystic Ovary Syndrome Patients

Background: The insulin resistance (IR) of the ovarian granulosa cells from polycystic ovary syndrome (PCOS) aggravates the abnormalities in steroidogenesis and anovulation, and chemerin is an adipokine involved in regulating adipogenesis and glucose homeostasis. The underlying mechanism of IR and the role of chemerin in the development of IR remain to be demonstrated. Methods: The granulosa-lutein cells (hGLs) and follicular fluid from PCOS and non-PCOS patients with or without IR were collected to determine the chemerin levels and molecules pertinent to insulin signaling. The effects and molecular mechanism of chemerin on the insulin signaling were investigated in cultured hGLs with immunofluorescence staining, special enzyme-linked immunosorbent assay (ELISA), quantitative real-time PCR (qRT-PCR), western blotting, [18F]-Fluorodeoxyglucose ([18F]-FDG) incorporation and siRNA transfection respectively. Findings: The chemerin levels were elevated in both follicular fluid and hGLs samples obtained from PCOS with IR patients and the hGLs obtained from PCOS with IR patients showed decreased insulin sensitivity and impaired glucose uptake capacity. Moreover, treatment of chemerin attenuated insulin-stimulated glucose uptake by decreasing phosphorylation of Akt and membrane translocation of glucose transporter type 4 (GLUT4) through increasing Ser307 phosphorylation of insulin receptor substrate 1 (IRS1) in cultured hGLs. These effects could be abolished by siRNA-mediated knockdown of chemokine-like receptor 1 (CMKLR1). Furthermore, insulin induced the expression of chemerin in hGLs. Interpretation: Our findings demonstrate a novel role of chemerin in the metabolic dysfunction of PCOS, which suggested that chemerin and its receptor can be further implicated as potential therapeutic targets in the future treatment of PCOS. Funding Statement: This work was supported by the National Natural Science Foundation of China [grant numbers 81771648, 81571499]; the National Key RD the Shanghai Commission of Science and Technology [grant number 17DZ2271100]; the Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant [grant number 20161413]; the Program of Shanghai Academic Research Leader in Shanghai Municipal Commission of Health and Family Planning [grant number 2017BR015]; and the Clinical Skills Improvement Project of Major Disorders, Hospital Development Center of Shanghai [grant number 16CR1022A] and Shanghai Technological Innovation Plan [grant number 18140902400]. Declaration of Interests: The authors report no conflicts of interest in this work. Ethics Approval Statement: All samples were collected with written informed consent under a protocol approved by the Ethics Committee of Renji Hospital.

Reduced expression of chemerin is associated with poor clinical outcome in acute myeloid leukemia.

Chemerin is dysregulation in numerous solid cancers. However, only little is known about the role of chemerin in acute myeloid leukemia (AML). In this study, we aimed to investigate the expression and clinical significance of recently described chemerin in acute myeloid leukemia (AML). The expression of chemerin in 149 patients with de novo AML and 35 normal controls was quantified by Real-time quantitative PCR (RQ-PCR). Chemerin was down-expressed in AML compared with controls (P=0.042). A receiver operating characteristic (ROC) curve revealed that chemerin expression could differentiate patients with AML from control subjects (AUC=0.611, 95% CI: 0.490-0.732; P=0.042) respectively. The cohort of AML patients was divided into two groups according to the cut-off value of 0.0826 (79% sensitivity and 54% specificity, respectively). In addition, the AML patients with low chemerin expression had significantly shorter overall survival (OS) than those with high chemerin expression (P=0.049). Moreover, multivariate survival analysis confirmed that chemerin was an independent prognostic factor for AML patients. In conclusion, downregulation of chemerin might be a useful diagnostic and prognostic factor for AML patients.

Effects of Aldosterone on Chemerin Expression And Secretion in 3T3-L1 Adipocytes.

Aldosterone plays a pivotal role in the pathogenesis of metabolic syndrome and cardiovascular disease; however, the underlying mechanisms have not been clarified. Chemerin has been characterized as an adipokine with crucial roles in obesity-associated disorders and cardiovascular homeostasis. The aim of the present study was to investigate the direct effects of aldosterone on chemerin expression and secretion in 3T3-L1 adipocytes and to identify the potential signalling pathways involved. Chemerin mRNA levels were measured using real-time PCR, whereas the levels of secreted chemerin in the culture media were determined using ELISA. Treatment with aldosterone induced time- and dose-dependent increases of chemerin gene expression and protein secretion, and effect that was mediated through the mineralocorticoid receptor. Signalling studies suggested that the NF-κB pathway is involved in aldosterone-induced chemerin expression. Taken together, our data demonstrate a direct interaction between aldosterone and chemerin in adipocytes, which may be an underlying mechanism linking aldosterone-associated metabolic abnormalities and cardiovascular disease.

Abstract P102: Liver Acquitted, Fat Indicted: Hepatic Chemerin Knockdown Does Not Reduce Blood Pressure While Whole-body Knockdown Does

Chemerin is an inflammatory adipokine positively associated with hypertension and obesity with the majority of chemerin thought to derive from the liver and adipose tissue. The contributions of liver-derived chemerin to plasma chemerin levels and blood pressure regulation are unknown. We compared whole-body vs liver chemerin inhibition using antisense oligonucleotides (ASO) with liver-restricted activity (GalNAc) or liver and fat activity (Gen 2.5). We hypothesized that in normotensive male SD rats, circulating chemerin is predominately liver-derived and regulates blood pressure. A scrambled ASO control and phosphate-buffered saline (PBS) were used as controls and radiotelemetry was used to monitor blood pressure. Baseline mean arterial blood pressure (MAP) was recorded for one week, beginning 5 days after surgery to establish a baseline. ASOs were given weekly by subcutaneous injections for four weeks. Two days after the final injection, animals were sacrificed for tissue RT-PCR and plasma chemerin measurements using Western analysis. Gen 2.5 chemerin ASO treatments (compared to PBS control) reduced chemerin mRNA in liver, retroperitoneal fat, and mesenteric perivascular adipose tissue (mPVAT) by 99.5% ± 0.1%, 95.2% ± 0.3%, and 69% ± 2%, respectively, and plasma chemerin was reduced to undetectable levels. GalNAc chemerin ASO treatments (compared to PBS control) reduced chemerin mRNA in liver by 97.9% but had no effect on chemerin expression in retroperitoneal fat and mPVAT; plasma chemerin was reduced by 90% ± 5%. Gen 2.5 chemerin ASO treatment reduced MAP, which reached a nadir of 7 ± 2.1 mmHg 48 – 72 hours after each dose compared to the scrambled ASO controls. By contrast, MAP was unchanged in animals receiving the GalNAc chemerin ASO. Thus, although most circulating chemerin is liver-derived, plasma chemerin does not play a role in blood pressure regulation. This study suggests that while chemerin is still generally associated with increased blood pressure, circulating chemerin levels cannot directly predict this effect. In addition, local effects of chemerin from fat may explain this discrepancy and support chemerin’s association with both hypertension and obesity.

Abstract 3690: The leukocyte chemoattractant chemerin modulates PTEN via CMKLR1 in human tumors

Abstract Background: Recent data in preclinical models has shown that phosphatase and tensin homolog (PTEN) loss correlated with decreased tumor immune cell infiltration as well as decreased response to T cell-based immunotherapy. Chemerin (RARRES2) is a recently identified endogenous leukocyte chemoattractant shown to recruit innate immune cells through its G-protein coupled receptor CMKLR1. Chemerin/RARRES2 is commonly downregulated in prostate and other cancers (e.g. sarcoma) compared to their normal tissue counterparts. Methylome-wide studies in multiple tumor types have identified RARRES2 as being one of the most hypermethylated genes, potentially leading to decreased chemerin expression. Our previous preclinical studies showed that forced overexpression of chemerin in tumors was capable of recruiting immune effector cells, including T cells, into the tumor microenvironment and suppressing tumor growth. Methods: In order to study the effects of chemerin overexpression on tumor cell intrinsic processes we exposed prostate and sarcoma tumor lines to exogenous recombinant chemerin in vitro. Evaluation of PTEN was performed at both the mRNA and protein levels, using both quantitative PCR and Western blotting, in comparison with normal prostate epithelia RWPE-1 as well as PTEN-null PC3 cells as controls. in vitro invasion assays were performed to investigate the functional impact of chemerin exposure on tumor intrinsic activity. Knockdown of CMKLR1 using siRNA was performed to determine its role in tumor response. Results: Using both prostate and sarcoma tumor lines, we found exogenous chemerin was able to significantly upregulate PTEN expression at both the mRNA and protein levels in a dose-response manner. Exposure to chemerin did not result in increased apoptosis or altered in vitro proliferation. Importantly, chemerin treatment significantly decreased in vitro tumor invasion. Knockdown studies showed CMKLR1 abrogation resulted in restored tumor migration, suggesting a link between this GPCR and PTEN expression and activity. Conclusions: For the first time, to our knowledge, we have shown a link between chemerin and PTEN expression and activity in both prostate and sarcoma tumor lines. Our collective study shows chemerin’s ability to upregulate PTEN activity and to mitigate tumor cell migration via CMKLR1. This work has functional implications on both tumor cell intrinsic and extrinsic responses to chemerin-based immunotherapeutic strategies. Further studies are needed to investigate the interaction between chemerin and PTEN signaling, and its connection to oncogenic signaling pathways manipulated in malignant tumors. Additionally, future in vivo studies using these tumor lines will help further elucidate the chemerin-PTEN axis and its role in tumor immunosurveillance. We hypothesize that increased chemerin-driven PTEN activity may help facilitate an improved immunotherapy response and functional ability to attack cancer cells. Citation Format: Keith R. Rennier, Ping Wang, Robert Crowder, Russell K. Pachynski. The leukocyte chemoattractant chemerin modulates PTEN via CMKLR1 in human tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3690. doi:10.1158/1538-7445.AM2017-3690

Evaluation of chemerin and its receptors, ChemR23 and CCRL2, in gingival tissues with healthy and periodontitis

Chemerin is a chemoattractant protein that directs inflammatory cells that express its receptor chemokine receptor-like 1 (ChemR23) towards sites of inflammation. C-C chemokine receptor-like 2 (CCRL2), is the other receptor of chemerin, improves the interaction between chemerin and ChemR23. The aim of this study was to evaluate the expression of chemerin and its receptors in gingival tissues with healthy and periodontitis. Tissue biopsy samples were obtained from 20 patients with chronic periodontitis and from the gingiva of 20 healthy individuals undergoing a crown lengthening process. Quantitative real-time PCR (qPCR) was used to examine the mRNA expression of chemerin, ChemR23 and CCRL2. Additionally, protein expression was measured by immunohistochemistry. Both qPCR and immunohistochemistry results revealed that the expression of chemerin and ChemR23 was significantly higher in tissues with periodontitis than in healthy tissues (P=0.001 and, P=0.015, respectively). There were no significant differences between healthy tissues and those with periodontitis in terms of mRNA expression of CCRL2, whereas a more intense staining was observed in tissues with periodontitis. The mRNA expression levels of chemerin showed a positive correlation with plaque index, gingival index, probing pocket depth and clinical attachment level (r=0.448, r=0.460, r=0.439 and, r=0.459, respectively, P<0.01). To the best of our knowledge, this study is the first to examine the expression of chemerin, ChemR23 and CCRL2 in gingival tissues. Our study suggests that chemerin may play a role in the pathogenesis of periodontitis by causing chemoattraction of immune cells that direct ChemR23 receptors to the site of inflammation.

Hepatic chemerin mRNA in morbidly obese patients with nonalcoholic fatty liver disease.

The aim of this study was to investigate hepatic chemerin mRNA, serum chemerin concentration, and immunohistochemical staining for chemerin and and chemokine receptor-like 1 (CMKLR1) in hepatic tissue in 56 morbidly obese women with nonalcoholic fatty liver disease (NAFLD) and to search for a relationship with metabolic and histopathological features. Chemerin mRNA was assessed by quantitative real-time PCR, chemerin, and CMKLR1 immunohistochemical expression with specific antibodies, while serum chemerin concentration was assessed with commercially available enzyme-linked immunosorbent assays. Serum chemerin concentration reached 874.1 ±234.6 ng/ml. There was no difference in serum chemerin levels between patients with BMI < 40 kg/m2 and ≥ 40 kg/m2. Serum chemerin concentration tended to be higher in patients with hepatocyte ballooning, greater extent of steatosis, and definite nonalcoholic steatohepatitis (NASH). Liver chemerin mRNA was observed in all included patients and was markedly, but insignificantly, higher in those with BMI ≥ 40 kg/m2, hepatocyte ballooning, greater extent of steatosis, and definite NASH. Hepatic chemerin mRNA might be a predictor of hepatic steatosis, hepatocyte ballooning, and NAFLD activity score (NAS) but seemed not to be a primary driver regulating liver necroinflammatory activity and fibrosis. The lack of association between serum chemerin and hepatic chemerin mRNA may suggest that adipose tissue but not the liver is the main source of chemerin in morbidly obese women.

Hepatic chemerin mRNA expression is reduced in human nonalcoholic steatohepatitis.

Chemerin is associated with insulin resistance and is expressed in the liver. Nonalcoholic fatty liver disease (NAFLD) is related to impaired insulin sensitivity, but studies evaluating hepatic and serum chemerin in NAFLD resulted in discordant data. Chemerin mRNA was determined in the liver tissue obtained from 33 controls and 76 NAFLD patients. Chemerin serum levels were measured in a different cohort of patients with ultrasound-diagnosed NAFLD and the respective controls. Hepatic stellate cells and hepatocytes were exposed to selected metabolites and nuclear receptor agonists to study the regulation of chemerin. Effect of recombinant chemerin on hepatocyte released proteins was analysed. Hepatic chemerin expression was not related to BMI, gender, type 2 diabetes and hypertension. Chemerin mRNA did not correlate with steatosis and was negatively associated with inflammation, fibrosis and nonalcoholic steatohepatitis (NASH) score. Patients with NASH had lower chemerin mRNA compared to those with borderline NASH and controls. Factors with a role in NASH mostly did not regulate chemerin in the liver cells. Of note, liver X receptor agonist reduced chemerin protein. Serum chemerin was not changed in NAFLD. Levels positively correlated with age, waist-to-hip ratio, systolic blood pressure, serum FGF21 and lipocalin 2, and negatively with transferrin saturation. Chemerin induced FGF21 in supernatants of primary human hepatocytes. Hepcidin, a major regulator of iron homoeostasis and lipocalin 2, were not regulated by chemerin. Chemerin mRNA is reduced in the liver of NASH patients, and liver X receptor seems to have a role herein.

Postweaning changes in the expression of chemerin and its receptors in calves are associated with the modification of glucose metabolism.

Chemerin, originally known as a chemoattractant derived from adipose tissue and the liver, has been reported to have regulatory functions in gluconeogenesis, peripheral insulin sensitivity, and insulin secretion. This study was conducted to assess the postweaning changes in expression of this cytokine and its physiological role in the modification of glucose metabolism associated with weaning. Eighteen tissue samples were collected from Holstein calves (90 d of age; n = 4) to investigate the tissue distributions of chemerin and its receptors genes. was highly expressed in the liver, and secreted chemerin protein was found in the plasma. Among the receptors of chemerin, and were ubiquitously expressed whereas was predominantly expressed in the liver. The changes in glucose metabolism and expression of these genes after weaning were assessed by comparing suckling calves (n = 6) and weaned calves (n = 8) of Japanese Black cattle. No significant difference was observed in plasma glucose levels between suckling and weaned calves (P = 0.22), whereas the plasma level of total ketone bodies was significantly higher in weaned calves (P < 0.01). Plasma levels of insulin and cortisol did not differ between suckling and weaned calves. The mRNA levels of certain key enzymes involved in hepatic gluconeogenesis were also altered; for instance, level was lower in postweaning calves (P < 0.05) and () level tended to be higher after weaning (P = 0.08). However, was not altered after weaning. The plasma levels of hepatic stress indicators were also changed, with aspartate transaminase, alanine transaminase, and lactate dehydrogenase being significantly elevated in postweaning calves (P < 0.05). Chemerin protein in liver tissue was less abundant in weaned calves (P < 0.05), although there were no changes in its transcript levels. The abundance of plasma chemerin protein did not change after weaning (P = 0.95). In summary, these data indicate that as a consequence of weaning, which causes physiological stress and alters hepatic metabolism, chemerin protein expression within the liver is downregulated, indicating that chemerin plays a role in the upregulation of hepatic expression via its inhibitory effect on hepatic gluconeogenesis.

Tumor Necrosis Factor-Alpha and the ERK Pathway Drive Chemerin Expression in Response to Hypoxia in Cultured Human Coronary Artery Endothelial Cells.

BackgroundChemerin, a novel adipokine, plays a role in the inflammation status of vascular endothelial cells. Hypoxia causes endothelial-cell proliferation, migration, and angiogenesis. This study was aimed at evaluating the protein and mRNA expression of chemerin after exposure of human coronary artery endothelial cells (HCAECs) to hypoxia.Methods and ResultsCultured HCAECs underwent hypoxia for different time points. Chemerin protein levels increased after 4 h of hypoxia at 2.5% O2, with a peak of expression of tumor necrosis factor-alpha (TNF-alpha) at 1 h. Both hypoxia and exogenously added TNF-alpha during normoxia stimulated chemerin expression, whereas an ERK inhibitor (PD98059), ERK small interfering RNA (siRNA), or an anti-TNF-alpha antibody attenuated the chemerin upregulation induced by hypoxia. A gel shift assay indicated that hypoxia induced an increase in DNA-protein binding between the chemerin promoter and transcription factor SP1. A luciferase assay confirmed an increase in transcriptional activity of SP1 on the chemerin promoter during hypoxia. Hypoxia significantly increased the tube formation and migration of HCAECs, whereas PD98059, the anti-TNF-alpha antibody, and chemerin siRNA each attenuated these effects.ConclusionHypoxia activates chemerin expression in cultured HCAECs. Hypoxia-induced chemerin expression is mediated by TNF-alpha and at least in part by the ERK pathway. Chemerin increases early processes of angiogenesis by HCAECs after hypoxic treatment.

Reduced expression of chemerin in visceral adipose tissue associates with hepatic steatosis in patients with obesity.

This study aimed to evaluate whether circulating levels and/or visceral adipose tissue (VAT) expression of recently described adipokines associate with histopathological severity of nonalcoholic fatty liver disease (NAFLD), independent of obesity and insulin resistance. Serum levels of adiponectin, omentin, chemerin, monocyte chemoattractant protein-1, and secreted frizzled-related protein 4 were measured using enzyme-linked immunosorbent assay in 81 patients with obesity and NAFLD and 18 lean control subjects. Expression in VAT was measured using real-time PCR and histopathological grading was scored using the NAFLD activity score (NAS). When NAFLD patients were subdivided into groups with simple steatosis, borderline nonalcoholic steatohepatitis (NASH), and NASH, adiponectin serum levels and omentin expression were lower in NASH versus simple steatosis patients. Serum adiponectin was generally lower with higher histopathological grading. Chemerin VAT expression was negatively associated with NAS (r = -0.331, P = 0.022) and steatosis score (r = -0.335, P = 0.020), independent of age, BMI, and HOMA-IR. In addition, adjusting for chemerin VAT expression in a multivariate model explained part of the association between NAS and HOMA-IR. These findings suggest that lower VAT expression of chemerin in patients with obesity may be involved in the pathophysiology of hepatic steatosis, potentially by modulating the link between insulin resistance and NAFLD.

1082 Gene expression and secretion of chemerin in bovine mammary epithelial cells

1082 Gene expression and secretion of chemerin in bovine mammary epithelial cells

Association of Chemerin and Vascular Endothelial Growth Factor (VEGF) with Diabetic Nephropathy.

BackgroundDiabetic nephropathy (DN) is a common complication of diabetes, caused by diabetic microvascular lesions. The pathogenesis of DN is complicated, involving genetics, physics, chemistry, and environmental factors. Chemerin is a fat cell factor that participates in regulating inflammation. Vascular endothelial growth factor (VEGF) promotes vascular endothelial cell proliferation, differentiation, and angiogenesis. The relationship role of Chemerin and VEGF in DN is not fully understood.Material/MethodsSD rats were randomly divided into 2 groups: the control group and the DN group. Streptozotocin was used to construct the DN model. Serum creatinine (Scr), blood urea nitrogen (BUN), and urine microalbumin (UAlb) were detected. Real-time PCR and Western blot were used to test Chemerin and VEGF mRNA and protein expression in kidney tissue. ELISA was performed to test TGF-β1, TNF-α, and INF-γ levels. The correlation of Chemerin and VEGF with renal function and inflammatory factors was analyzed.ResultsDN group rats showed obviously increased Scr and BUN levels, and elevated TGF-β1, TNF-α, and INF-γ secretion (P<0.05). Compared with controls, Chemerin and VEGF were clearly overexpressed in the DN group (P<0.05). Chemerin and VEGF expression were positively correlated with inflammatory factors and renal function.ConclusionsChemerin and VEGF play important roles in DN by regulating inflammatory factors and renal function. They may be treated as indicators of DN.

The adipokine chemerin amplifies electrical field-stimulated contraction in the isolated rat superior mesenteric artery.

The adipokine chemerin causes arterial contraction and is implicated in blood pressure regulation, especially in obese subjects with elevated levels of circulating chemerin. Because chemerin is expressed in the perivascular adipose tissue (PVAT) that surrounds the sympathetic innervation of the blood vessel, we tested the hypothesis that chemerin (endogenous and exogenous) amplifies the sympathetic nervous system in mediating electrical field-stimulated (EFS) contraction. The superior mesenteric artery, with or without PVAT and with endothelium and sympathetic nerve intact, was mounted into isolated tissue baths and used for isometric contraction and stimulation. Immunohistochemistry validated a robust expression of chemerin in the PVAT surrounding the superior mesenteric artery. EFS (0.3-20 Hz) caused a frequency-dependent contraction in isolated arteries that was reduced by the chemerin receptor ChemR23 antagonist CCX832 alone (100 nM; with, but not without, PVAT), but not by the inactive congener CCX826 (100 nM). Exogenous chemerin-9 (1 μM)-amplified EFS-induced contraction in arteries (with and without PVAT) was blocked by CCX832 and the α-adrenergic receptor antagonist prazosin. CCX832 did not directly inhibit, nor did chemerin directly amplify, norepinephrine-induced contraction. Whole mount immunohistochemical experiments support colocalization of ChemR23 with the sympathetic nerve marker tyrosine hydroxylase in superior mesenteric PVAT and, to a lesser extent, in arteries and veins. These studies support the idea that exogenous chemerin modifies sympathetic nerve-mediated contraction through ChemR23 and that ChemR23 may be endogenously activated. This is significant because of the well-appreciated role of the sympathetic nervous system in blood pressure control.

Emerging role of adipokines in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by multisystem organ involvement and unclear pathogenesis. Several adipokines synthesized in the adipose tissue, including leptin, adiponectin, resistin, and chemerin, have been explored in autoimmune rheumatic diseases, especially SLE, and results suggest that these mediators may be implicated in the pathogenesis of SLE. However, the current results are controversial. In this review, we will briefly discuss the expression and possible pathogenic role of several important adipokines, including leptin, adiponectin, resistin, and chemerin in SLE.

Reduced expression of chemerin in visceral adipose tissue associates with hepatic steatosis in obese patients

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)