Chemerin Expression Research Articles

Prognostic value of plasma adipokine chemerin in patients with coronary artery disease

BackgroundAdipokine chemerin was proven to be associated with coronary artery disease (CAD), but its prognostic implications in CAD remain unclear.MethodsThis study consists of two parts, one is a basic study and the other is a clinical cohort study. First, we investigated the differential expression of six adipokines in the atherosclerotic mice model compared to mice with milder degrees of atherosclerosis and mice without atherosclerosis using microarray data. We then examined the potential of chemerin as a diagnostic and prognostic indicator in a CAD cohort. A total of 152 patients were enrolled in our study, including 77 patients with angiographically proven CAD and 75 control subjects without cardiovascular disease. Plasma adipokine chemerin levels were measured in all patients, and major adverse cardiovascular events (MACEs) were followed up, including ischemic stroke, non-fatal myocardial infarction, revascularization, and cardiovascular death.ResultsIn the aortas of atherosclerotic mice, chemerin expression was up-regulated compared to control mice. The plasma chemerin levels of CAD patients were higher than those of non-CAD patients (128.93 ± 37.06 vs. 109.85 ± 27.47 mmol/L, respectively, P < 0.001). High chemerin levels were an independent predictor of CAD (β = 2.702, 95% CI, 1.344–5.431, P = 0.001). We followed up with patients for a median duration of 5.5 years (3.9–5.6). The Kaplan–Meier curves showed that patients in the high chemerin group had a significantly higher risk of MACEs than the low chemerin group in patients with CAD (log-rank P = 0.003), not with non-CAD (Log-rank P = 0.120). Furthermore, Cox multivariate analysis revealed that high chemerin levels were an independent predictor of MACEs (HR 2.267; 95% CI, 1.139–4.515; P = 0.020). Finally, the cellular study showed that chemerin is predominantly expressed in PBMC-derived macrophages.ConclusionPlasma chemerin levels were increased in the CAD patients, and a high chemerin level increased the risk of MACEs in CAD patients.

Chemerin plasma levels are increased in COVID-19 patients and are an independent risk factor of mortality.

BackgroundChemerin is an extracellular protein with chemotactic activities and its expression is increased in various diseases such as metabolic syndrome and inflammatory conditions. Its role in lung pathology has not yet been extensively studied but both known pro- and anti-inflammatory properties have been observed. The aim of our study was to evaluate the involvement of the chemerin/ChemR23 system in the physiopathology of COVID-19 with a particular focus on its prognostic value.MethodsBlood samples from confirmed COVID-19 patients were collected at day 1, 5 and 14 from admission to Erasme Hospital (Brussels – Belgium). Chemerin concentrations and inflammatory biomarkers were analyzed in the plasma. Blood cells subtypes and their expression of ChemR23 were determined by flow cytometry. The expression of chemerin and ChemR23 was evaluated on lung tissue from autopsied COVID-19 patients by immunohistochemistry (IHC).Results21 healthy controls (HC) and 88 COVID-19 patients, including 40 in intensive care unit (ICU) were included. Plasma chemerin concentration were significantly higher in ICU patients than in HC at all time-points analyzed (p<0.0001). Moreover, they were higher in deceased patients compared to survivors (p<0.05). Logistic univariate regression and multivariate analysis demonstrated that chemerin level at day 14 of admission was an independent risk factor for death. Accordingly, chemerin levels correlated with inflammatory biomarkers such as C-reactive protein and tumor necrosis factor α. Finally, IHC analysis revealed a strong expression of ChemR23 on smooth muscle cells and chemerin on myofibroblasts in advanced acute respiratory distress syndrome (ARDS).DiscussionIncreased plasma chemerin levels are a marker of severity and may predict death of COVID-19 patients. However, multicentric studies are needed, before chemerin can be considered as a biomarker of severity and death used in daily clinical practice. Further studies are also necessary to identify the precise mechanisms of the chemerin/ChemR23 system in ARDS secondary to viral pneumonia.

The Chemerin/CMKLR1 Axis Is Involved in the Recruitment of Microglia to Aβ Deposition through p38 MAPK Pathway.

The accumulation of microglia around senile plaques is one of the pathological features of Alzheimer’s disease (AD). Chemerin is an adipokine with immune-modulating properties. Our previous study showed that chemokine-like receptor 1 (CMKLR1), the receptor for chemerin, is also a functional receptor of Aβ. However, it remains unclear whether and how the chemerin/CMKLR1 axis affects the migration of microglia. The impact of CMKLR1 on microglial activation and recruitment toward Aβ deposits was examined in APP/PS1 mice mated with CMKLR1 knockout (CMKLR1−/−) mice. CMKLR1 deficiency reduced the number of microglia around Aβ deposits in aged APP/PS1-CMKLR1−/− mice compared with APP/PS1 mice. Chemerin expression was significantly decreased in the hippocampus and cortex of aged APP/PS1 mice compared with WT mice. In vitro assays demonstrated that activation of the chemerin/CMKLR1 axis promoted the migration of primary cultures of microglia and murine microglial N9 cells. Mechanistic studies found that chemerin/CMKLR1 induced polarization and protrusion formation of microglia by promoting the remodeling of actin filaments and microtubules, and Golgi apparatus reorientation. The inhibition of p38 MAPK attenuated the promotion of the chemerin/CMKLR1 axis on microglial migration and polarization. In addition, chemerin inhibited Aβ-induced microglial clustering. The inhibition of p38 MAPK alleviated the suppressive effect of chemerin on Aβ-induced microglial aggregation. Our data indicate that the chemerin/CMKLR1 axis is involved in the migration and recruitment of microglia to senile plaques via the p38 MAPK pathway. Modulation of the chemerin/CMKLR1 axis is a potential new strategy for AD therapy.

The Chemerin-CMKLR1 Axis is Functionally important for Central Regulation of Energy Homeostasis.

Chemerin is an adipokine involved in inflammation, adipogenesis, angiogenesis and energy metabolism, and has been hypothesized as a link between obesity and type II diabetes. In humans affected by obesity, chemerin gene expression in peripheral tissues and circulating levels are elevated. In mice, plasma levels of chemerin are upregulated by high-fat feeding and gain and loss of function studies show an association of chemerin with body weight, food intake and glucose homeostasis. Therefore, chemerin is an important blood-borne mediator that, amongst its other functions, controls appetite and body weight. Almost all studies of chemerin to date have focused on its release from adipose tissue and its effects on peripheral tissues with the central effects largely overlooked. To demonstrate a central role of chemerin, we manipulated chemerin signaling in the hypothalamus, a brain region associated with appetite regulation, using pharmacological and genetic manipulation approaches. Firstly, the selective chemerin receptor CMKLR1 antagonist α-NETA was administered i.c.v. to rats to test for an acute physiological effect. Secondly, we designed a short-hairpin-RNA (shRNA) lentivirus construct targeting expression of CMKLR1. This shRNA construct, or a control construct was injected bilaterally into the arcuate nucleus of male Sprague Dawley rats on high-fat diet (45%). After surgery, rats were maintained on high-fat diet for 2 weeks and then switched to chow diet for a further 2 weeks. We found a significant weight loss acutely and inhibition of weight gain chronically. This difference became apparent after diet switch in arcuate nucleus-CMKLR1 knockdown rats. This was not accompanied by a difference in blood glucose levels. Interestingly, appetite-regulating neuropeptides remained unaltered, however, we found a significant reduction of the inflammatory marker TNF-α suggesting reduced expression of CMKLR1 protects from high-fat diet induced neuroinflammation. In white and brown adipose tissue, mRNA expression of chemerin, its receptors and markers of adipogenesis, lipogenesis and brown adipocyte activation remained unchanged confirming that the effects are driven by the brain. Our behavioral analyses suggest that knockdown of CMKLR1 had an impact on object recognition. Our data demonstrate that CMKLR1 is functionally important for the central effects of chemerin on body weight regulation and neuroinflammation.

The Regulatory Roles of Chemerin-Chemokine-Like Receptor 1 Axis in Placental Development and Vascular Remodeling During Early Pregnancy.

Chemerin is an adipokine that regulates metabolism in pregnancy. An elevation of serum chemerin level is associated with pregnancy complications. Consistently, we demonstrated that the chemerin expression was increased in placenta of preeclamptic patients at deliveries. The G protein-coupled receptor chemokine-like receptor 1 (CMKLR1) mediates the actions of chemerin. The functions of the chemerin-CMKLR1 axis in maintaining pregnancy are still unknown. In this study, we demonstrated that CMKLR1 was expressed in the decidual natural killer (dNK) cells and chorionic villi of human. Chemerin suppressed the proliferation of the dNK cells in vitro. Specific antagonist of CMKLR1, α-Neta abolished the suppressive effect of spent medium from chemerin-treated dNK cells culture on extravillous trophoblast invasion. Activation of the chemerin-CMKLR1 axis promoted fusion and differentiation of human cytotrophoblast to syncytiotrophoblast in vitro. We generated Cmklr1 knockout mice and showed that the Cmklr1 deficiency negatively affected pregnancy outcome in terms of number of implantation sites, litter size and fetal weight at birth. Histologically, the Cmklr1 deficiency impaired formation of the syncytiotrophoblast layer II, induced enlargement of the maternal lacunae in the labyrinth, increased the diameter of the spiral arteries and increased trophoblast invasion in the decidua. The Cmklr1 deficient placenta also displayed an increased number of dNK cells and serum IL-15 level. In summary, the chemerin-CMKLR1 axis regulated placental development and spiral artery remodeling in early pregnancy.

Immunohistochemical identification and assessment of the location of leptin, visfatin and chemerin in the liver of men with different body mass index

BackgroundAdipokines such as leptin, visfatin and chemerin play a pivotal role not only in the pathogenesis of excessive weight gain but also impact on hepatic metabolism. However, alterations in the production of these peptides in the liver of overweight individuals have not been fully elucidated yet. The aim of the study was to evaluate changes in leptin, visfatin and chemerin biosynthesis in the liver of men with different BMI.MethodsFourteen adult men without symptoms from the digestive system were recruited. Research material consisted of liver samples. Study participants were divided into two groups: lean (BMI ≤ 25 kg/m2) and overweight subjects (BMI > 25 kg/m2). Paraffin liver sections were processed by immunohistochemistry for detection of leptin, visfatin and chemerin. Hepatic expression of leptin, visfatin and chemerin genes was determined by qRT-PCR method.ResultsIncreased immunoreactivity for leptin and chemerin, and decreased immunoreaction for visfatin were observed in the liver of overweight men in comparison to lean subjects. Overweight subjects with hepatic steatosis displayed increased immunoreactivity for leptin and weaker immunoreaction against visfatin and chemerin in the liver, compared to individuals with normal organ structure. Expression of leptin and chemerin was enhanced in the liver of overweight individuals, with the highest expression observed in subjects with hepatic steatosis. Conversely, expression of visfatin in the male liver was decreased in overweight subjects and those with and liver steatosis.ConclusionsThe present study proves that the expression of leptin, visfatin and chemerin in the male liver is altered in overweight individuals. Our report also indicates the potential importance of these peptides in hepatic steatosis associated with overweight.

Targeting Adipose Tissues with ATS9R Nanoparticles for Drug Delivery

Nanoparticles (NPs) are a drug delivery system that can enable delivery of a drug to a targeted tissue. Previous studies have shown that the use of an adipose targeting sequence (ATS) peptide in conjunction with a drug in the form of a NP has the ability to selectively deliver the drug to mouse adipose tissues. The prohibitin protein located in adipose tissue is the target of ATS. Adipose tissue is a major source of the adipokine chemerin, a prohypertensive protein. Our laboratory has proven that liver derived chemerin, the largest source of circulating chemerin, is biologically inactive. Our goal is to understand if chemerin produced by adipose tissue contributes to hypertension. We hypothesize an ATS drug delivery system could be applied in rats to specifically reduce the levels of adipose tissue associated chemerin. We created a NP consisting of an antisense oligonucleotide (ASO) against chemerin and a FITC labeled ATS with 9 arginine sequence (ATS9R). In vitro studies showed that the ASO is functional when incorporated into NPs with ATS9R as it reduced chemerin mRNA expression in isolated epidydimal (Epi) adipocytes by 43‐fold compared to vehicle incubated cells (Veh mean 2‐ΔCT=0.039 ± 0.007; NP mean 2‐ΔCT=0.0009 ± 0.0001), and 13‐fold in isolated retroperitoneal (RP) adipocytes (Veh mean 2‐ΔCT=0.041 ± 0.007; NP mean 2‐ΔCT=0.0031 ± 0.0009) of Dahl SS rats. Ex vivo studies support the ability of the ATS9R‐ASO NP to reduce chemerin mRNA expression in tissues. In Epi fat incubated with the NP overnight at 37 oC, chemerin expression was reduced by 2.7‐fold (p&lt;0.05) (Veh mean 2‐ΔCT=0.213 ± 0.088; NP mean 2‐ΔCT=0.079 ± 0.013). The NP also reduced chemerin expression in RP fat by 2.1‐fold (Veh mean 2‐ΔCT=0.159 ± 0.027; NP mean 2‐ΔCT=0.071 ± 0.011), although the changes did not reach statistical significance. However, this same NP was unable to deliver the ASO selectively to adipose tissue in vivo. Two days after subcutaneous injections in Dahl SS rats, the NP caused a significant (p&lt;0.05) 2.4‐fold reduction in liver chemerin mRNA expression compared to vehicle treated animals (Veh 2‐ΔCT=0.753; NP mean 2‐ΔCT=0.311 ± 0.007), but not in Epi (1.8‐fold reduction; Veh 2‐ΔCT=0.175; NP mean 2‐ΔCT=0.095 ± 0.013) or RP fat (1.9‐fold reduction; Veh 2‐ΔCT=0.120; NP mean 2‐ΔCT=0.061 ± 0.015). Varying NP dose, administration route, and concentration of the components constituting the NP did not show any improvement in ASO delivery to fats vs liver. Further studies are needed to develop the ATS9R system to deliver ASO to adipose tissue beds in rats.

Chemerin Effect on the Endometrial Proteome of the Domestic Pig during Implantation Obtained by LC-MS/MS Analysis.

Chemerin (CHEM) is a hormone mainly expressed in adipocytes involved in the regulation of energy homeostasis and inflammatory response. CHEM expression has been demonstrated in the structures of the porcine hypothalamic-pituitary-gonadal axis, as well as in the uterus, trophoblasts and conceptuses of pigs. In this study, we performed high-throughput proteomic analyses (liquid chromatography with tandem mass spectrometry, LC-MS/MS) to examine the influence of CHEM (400 ng/mL) on differentially regulated proteins (DRPs) in the porcine endometrial tissue explants during implantation (15 to 16 days of gestation). Among all 352 DRPs, 164 were up-regulated and 188 were down-regulated in CHEM-treated group. DRPs were assigned to 47 gene ontology (GO) terms (p-adjusted < 0.05). Validation of four DRPs (IFIT5, TGFβ1, ACO1 and PGRMC1) by Western blot analysis confirmed the veracity and accuracy of the LC-MS/MS method used in the present study. We suggest that CHEM, by modulating various protein expressions, takes part in the endometrial cell proliferation, migration and invasion at the time of implantation. It also regulates the endometrial immune response, sensitivity to P4 and the formation of new blood vessels. Additionally, CHEM appears to be an important factor involved in endothelial cell dysfunction during the pathogenesis of preeclampsia. The identification of a large number of DRPs under the influence of CHEM provides a valuable resource for understanding the molecular mechanisms of this hormone action during implantation, which is a prerequisite for better control of pig reproduction.

Chemerin Regulates the Proliferation and Migration of Pulmonary Arterial Smooth Muscle Cells via the ERK1/2 Signaling Pathway.

Pulmonary arterial hypertension (PAH) is an incurable disease with high mortality. Chemerin has been found to be associated with pulmonary hypertension (PH). However, the specific role of chemerin in mediating PH development remains unclear. This study aimed to elucidate the regulatory effects and the underlying mechanism of chemerin on PH and to investigate the expression levels of chemerin protein in plasma in PAH patients. In vivo, two animal models of PH were established in rats by monocrotaline (MCT) injection and hypoxia. We found that the expression levels of chemerin and its receptor, chemokine-like receptor 1 (CMKLR1), were significantly upregulated in the lungs of PH rats. Primary cultured pulmonary arterial smooth muscle cells [(PASMCs) (isolated from pulmonary arteries of normal healthy rats)] were exposed to hypoxia or treated with recombinant human chemerin, we found that CMKLR1 expression was upregulated in PASMCs in response to hypoxia or chemerin stimulation, whereas the exogenous chemerin significantly promoted the migration and proliferation of PASMCs. Notably, the regulatory effects of chemerin on PASMCs were blunted by PD98059 (a selective ERK1/2 inhibitor). Using enzyme linked immunosorbent assay (ELISA), we found that the protein level of chemerin was also markedly increased in plasma from idiopathic pulmonary arterial hypertension (IPAH) patients compared to that from healthy controls. Moreover, the diagnostic value of chemerin expression in IPAH patients was determined through receiver operating characteristic (ROC) curve analysis and the result revealed that area under ROC curve (AUC) for plasma chemerin was 0.949. Taken together, these results suggest that chemerin exacerbates PH progression by promoting the proliferation and migration of PASMCs via the ERK1/2 signaling pathway, and chemerin is associated with pulmonary hypertension.

Placental trophoblast-specific overexpression of chemerin induces preeclampsia-like symptoms.

Maternal circulating levels of the adipokine chemerin are elevated in preeclampsia, but its origin and contribution to preeclampsia remain unknown. We therefore studied (1) placental chemerin expression and release in human pregnancy, and (2) the consequences of chemerin overexpression via lentivirus-mediated trophoblast-specific gene manipulation in both mice and immortalized human trophoblasts. Placental chemerin expression and release were increased in women with preeclampsia, and their circulating chemerin levels correlated positively with the soluble Fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio, a well-known biomarker of preeclampsia severity. Placental trophoblast chemerin overexpression in mice induced a preeclampsia-like syndrome, involving hypertension, proteinuria, and endotheliosis, combined with diminished trophoblast invasion, a disorganized labyrinth layer, and up-regulation of sFlt-1 and the inflammation markers nuclear factor-κB (NFκB), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β. It also led to embryo resorption, while maternal serum chemerin levels correlated negatively with fetal weight in mice. Chemerin overexpression in human trophoblasts up-regulated sFlt-1, reduced vascular endothelial factor-A, and inhibited migration and invasion, as well as tube formation during co-culture with human umbilical vein endothelial cells (HUVECs). The chemokine-like receptor 1 (CMKLR1) antagonist α-NETA prevented the latter phenomenon, although it did not reverse the chemerin-induced down-regulation of the phosphoinositide 3-kinase/Akt pathway. In conclusion, up-regulation of placental chemerin synthesis disturbs normal placental development via its CMKLR1 receptor, thereby contributing to fetal growth restriction/resorption and the development of preeclampsia. Chemerin might be a novel biomarker of preeclampsia, and inhibition of the chemerin/CMKLR1 pathway is a promising novel therapeutic strategy to treat preeclampsia.

Neutrophils Promote Tumor Progression in Oral Squamous Cell Carcinoma by Regulating EMT and JAK2/STAT3 Signaling Through Chemerin.

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity. In the tumor microenvironment, tumor-associated neutrophils (TANs) can promote tumor growth, invasion, and metastasis. The aim of our study was to explore the relationship between neutrophils infiltration and Chemerin expression in tumor cells, as well as their relationship with the clinicopathological parameters and clinical prognosis of 74 cases of OSCC. We also explored the role of the interaction between neutrophils and Chemerin in the functions of OSCC cells (Cal27, SCC9, and SCC15) in vitro. Our results showed that in OSCC, Chemerin over-expression may increase neutrophils infiltration in tumor tissues. Chemerin over-expression and neutrophils infiltration were the prognostic factors of poor clinical outcomes. Furthermore, we discovered that neutrophils promoted OSCC migration, invasion, and proliferation and EMT through Chemerin. Neutrophils activated JAK2/STAT3 signaling through Chemerin and then up-regulated its downstream signaling target genes, such as Phospho-Rb, E2F1, CyclinE1, and CyclinD1. Taken together, our results revealed that neutrophils and Chemerin are potentially involved in OSCC progression and metastasis. Neutrophils may promote the JAK2/STAT3 signaling pathway and EMT in OSCC cells through Chemerin.

Expression of chemerin in intestinal mucosa of calves with comparable expression level with other antimicrobial proteins.

Neonatal calves are highly susceptible to infectious disorders including diarrhea. Therefore, epithelial innate immunity, including antimicrobial peptides/proteins (AMPs), is important during the early stage of their lives. Chemerin, a multifunctional protein that was originally identified as a chemokine, possesses a potent antimicrobial activity. The present study investigated the expression levels of chemerin in the gastrointestinal (GI) tract of growing calves. Chemerin and its coding gene, retinoic acid receptor responder protein 2 (RARRES2), were highly expressed in duodenum, jejunum, and ileum compared with other parts of the GI tract. Immunohistochemistry demonstrated that chemerin-producing cells were localized in the crypt of the intestinal mucosa. Finally, the expression level of RARRES2 was higher compared with those of other major AMPs in duodenum, although it was lower compared with that of enteric β-defensin but mostly higher than those of other AMPs in jejunum and ileum at various ages in calves. The expression levels of RARRES2 were not influenced by the age of calves in duodenum and jejunum, whereas a higher expression level of RARRES2 in ileum was observed in younger calves. This study revealed that chemerin is produced in the small intestine of calves and has the potential to contribute to the gut epithelial barrier system.

Down Regulation of Chemerin and Resistin in Type II Diabetic Rats Treated With Silver Nanoparticles Synthetized Using Eryngium thyrsoideum Boiss Extract

Introduction: Diabetes is related to the higher production of inflammatory markers such as chemerin and resistin. Hypoglycemic influences of Eryngium thyrsoideum Boiss and silver nanoparticles (SNPs) have been established. The present study investigated the impacts of chemically or biologically synthesized SNPs using E. thyrsoideum extract on chemerin and resistin gene expressions in type II diabetic rats. Methods: Twenty male Wistar rats weighing 180-200 g were used. Type 2 diabetes was induced by nicotinamide and streptozotocin. Saline and 2.5 mg/kg chemically or biologically synthesized SNPs were injected to diabetic rats for two weeks. Five healthy rats received saline for two weeks. One day after the last injection, fasting blood samples were collected. Mean serum concentrations of glucose, creatinine, urea, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured by spectrophotometry. The gene expression of chemerin and resistin was determined by real-time polymerase chain reaction (PCR). Results: Mean serum concentrations of glucose, urea, ALT, AST, and mean relative gene expression of chemerin and resistin remarkably decreased in the diabetic group receiving SNPs prepared by either the chemical method or using Eryngium extract compared to the diabetic control group. Serum creatinine concentration did not change significantly in the control diabetic or diabetic groups receiving SNPs prepared either chemically or using the Eryngium extract. Conclusion: Chemically or green synthesized SNPs prevent liver hepatocyte damage. They reduced inflammatory factors via exerting hypoglycemic effects.

PEX-168 improves insulin resistance, inflammatory response and adipokines in simple obese mice: a mechanistic exploration

BackgroundPolyethylene glycol loxenatide (PEX-168) is a new antidiabetic drug; as such, there are not yet any reports on its weight loss effect. Therefore, this trial was designed to investigate the effect of PEX-168 on simple obese mice.MethodsThirty healthy male C57BL/6 mice were randomly selected and divided into a control group (NC) and an obesity model group. The high-fat diet-induced simple obesity mice were divided into a model control group (HF) and three intervention groups. The intervention groups were injected with different doses of PEX-168 intraperitoneally once a week for 12 weeks (low (LD), medium (MD) and high (HD)). Fasting blood glucose (FBG), body weight and food intake were measured from 1 to 12 weeks after PEX-168 injection. The serum insulin (INS), C-reactive protein (CRP), chemerin and omentin levels were measured after 12 weeks.ResultsCompared with the HF group, the low dose of PEX-168 reduced the body weight of the mice in a short period of time (8 weeks), and the mice in the MD and HD groups showed a significant decrease in body weight (P < 0.05). The low dose of PEX-168 could effectively improve the blood glucose and homeostasis model assessment of insulin resistance (Homa-IR) of the mice (FBG P < 0.05 INS, Homa-IR P < 0.001), but there was no significant difference between different doses (P > 0.05). CRP levels in the MD and HD groups were significantly improved (P < 0.05). The levels of serum chemerin and omentin in the intervention groups were also significantly improved (P < 0.01), but there was no significant difference between the different doses (P > 0.05).ConclusionsPEX-168 significantly reduced the body weight of simple obese mice and improved the insulin resistance. PEX-168 may regulate the expression of chemerin and omentin through its hypoglycaemic effect, and the weight-reducing effect of PEX-168 is unlikely to be the reason for the changes in both.

Chemerin regulates autophagy to participate in polycystic ovary syndrome.

ObjectivePolycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in women of reproductive age. Chemerin has recently been discovered as a novel adipokine associated with obesity and metabolic syndrome. Excessive autophagy activity and overexpression of autophagy-related genes in follicular granulosa cells are important mechanisms of PCOS. This study aimed to investigate the effect of chemerin on autophagy in PCOS.MethodsA rat model of PCOS was established by subcutaneous injection of testosterone propionate under a high-fat diet. Expression levels of chemerin and its receptor CMKLR1 were determined by real-time polymerase chain reaction and western blot. Proliferation and apoptosis of human granulosa cells in vitro and expression of autophagy-related genes were examined using bafilomycin A1 (autophagy inhibitor) and Torin1 (autophagy inducer).ResultsChemerin and CMKLR1 expression were significantly increased in the ovary in a rat model of PCOS. Ectopic expression of chemerin promoted the proliferation and inhibited the apoptosis of COV434 cells. Ectopic expression of chemerin also induced autophagy by inhibiting the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway.ConclusionsChemerin and CMKLR1 were overexpressed in PCOS rats. Chemerin promoted autophagy through inhibiting the PI3K/Akt/mTOR pathway, and may provide a potential target and biomarker of PCOS.

Chemokine-like Receptor 1 in Brain of Spontaneously Hypertensive Rats Mediates Systemic Hypertension.

Adipocytokine chemerin is a biologically active molecule secreted from adipose tissue. Chemerin elicits a variety of functions via chemokine-like receptor 1 (CMKLR1). The cardiovascular center in brain that regulates blood pressure (BP) is involved in pathophysiology of systemic hypertension. Thus, we explored the roles of brain chemerin/CMKLR1 on regulation of BP in spontaneously hypertensive rats (SHR). For this aim, we examined effects of intracerebroventricular (i.c.v.) injection of CMKLR1 small interfering (si)RNA on both systemic BP as measured by tail cuff system and protein expression in paraventricular nucleus (PVN) of SHR as determined by Western blotting. We also examined both central and peripheral protein expression of chemerin by Western blotting. Systolic BP of SHR but not normotensive Wistar Kyoto rats (WKY) was decreased by CMKLR1 siRNA. The decrease of BP by CMKLR1 siRNA persisted for 3 days. Protein expression of CMKLR1 in PVN of SHR tended to be increased compared with WKY, which was suppressed by CMKLR1 siRNA. Protein expression of chemerin in brain, peripheral plasma, and adipose tissue was not different between WKY and SHR. In summary, we for the first time revealed that the increased protein expression of CMKLR1 in PVN is at least partly responsible for systemic hypertension in SHR.

Serum and follicular fluid chemerin and chemerin mRNA expression in women with polycystic ovary syndrome: Systematic review and meta-analysis.

IntroductionPolycystic ovary syndrome (PCOS) is one of the most common endocrine disorders among women of reproductive age. Chemerin, a novel adipokine, is involved in inflammation, energy metabolism, adipogenesis, angiogenesis and insulin secretion in the adipose cells and ovary. This systematic review with meta‐analysis aimed to compare serum and follicular fluid (FF) chemerin and ovarian chemerin mRNA expression among women with PCOS and non‐PCOS.MethodsElectronic databases including Web of Science, PubMed, Google Scholar, Scopus, Cochrane and CINAHL were used for a comprehensive search through April 2021. Of the 174 articles initially identified, 22 studies met the eligibility criteria. A random‐effects model with a weighted mean difference (WMD) and 95% confidence interval (CI) was performed to compare the outcomes between groups. Subgroup and sensitivity analyses were performed to detect the sources of heterogeneity.ResultsWomen with PCOS compared to without PCOS showed significantly higher serum chemerin [WMD: 12.02 pg/ml (95% CI: [10.92, 13.13]), p < .001], chemerin mRNA expression [WMD: 0.38% (95% CI [0.25, 0.52]), p = .001] and FF chemerin [(WMD): 41.7 pg/ml (95% CI [17.89, 65.5]) p < .001]. Further, serum chemerin remained high in PCOS women even with subgroup analysis based on body mass index (BMI) or sample size (p < .001). Serum chemerin was higher in women with PCOS and higher BMI [(WMD): 3.29 pg/ml (95% CI: [2.73, 3.384]), p < .001]. The expression of chemerin mRNA was significantly higher in the PCOS group compared to the control group [WMD: 0.38% (95% CI [0.25, 0.52]), p < .001].ConclusionSerum and FF chemerin and mRNA expression were higher in the PCOS group compared to the controls. Further, serum chemerin was higher in PCOS women with higher BMI compared to lower BMI. The present findings illustrate that chemerin may be associated with PCOS status and BMI, independently.

The antitumoral effects of chemerin are independent from leukocyte recruitment and mediated by inhibition of neoangiogenesis.

Chemerin, a multifunctional protein acting through the receptor ChemR23/CMKLR1, is downregulated in various human tumors and was shown to display antitumoral properties in mouse models of cancer. In the present study, we report that bioactive chemerin expression by tumor cells delays the growth of B16 melanoma and Lewis lung carcinoma in vivo. A similar delay is observed when chemerin is not expressed by tumor cells but by keratinocytes of the host mice. The protective effect of chemerin is mediated by CMKLR1 and appears unrelated to the recruitment of leukocyte populations. Rather, tumors grown in the presence of chemerin display a much smaller number of blood vessels, hypoxic regions early in their development, and larger necrotic areas. These observations likely explain the slower growth of the tumors. The anti-angiogenic effects of chemerin were confirmed in a bead sprouting assay using human umbilical vein endothelial cells. These results suggest that CMKLR1 agonists might constitute therapeutic molecules inhibiting the neoangiogenesis process in solid tumors.

Crosstalk of hypothalamic chemerin, histamine, and AMPK in diet-and olanzapine-induced obesity in rats

AimContradiction overwhelms chemerin link to feeding behavior. Neither the chemerin central role on appetite regulation nor its relation to hypothalamic histamine and AMPK is verified. Main methodsFood intake, body weight and hypothalamic biochemical changes were assessed after a single intra-cerebroventricular or intraperitoneal injection (ip) (1 μg/kg or 16 μg/kg, respectively) or chronic ip administration (8 μg/kg/day) of chemerin for 14 or 28 days. Hypothalamic neurobiochemical changes in chemerin/histamine/AMPK induced by either 8-week high fat diet (HFD) or food restriction were also investigated. To confirm chemerin-histamine crosstalk, these neurobiochemical changes were assessed under settings of H1-receptor agonism and/or antagonism by betahistine and/or olanzapine, respectively for 3 weeks. Key findingsChemerin-injected rats exhibited anorexigenic behavior in both acute and chronic studies that was associated with a decreased AMPK activity in the arcuate nucleus (ARC). However, with long-term administration, chemerin anorexigenic effect gradually ceased. Contrarily to food restriction, 8-week HFD increased ARC expression of chemerin and its receptor CMKLR1, reducing food intake via an interplay of H1-receptors and AMPK activity. Blockage of H1-receptors by olanzapine disrupted chemerin signaling pathway with an increased AMPK activity, augmenting food intake. These changes were reversed to normal by betahistine coadministration. SignificanceChemerin is an anorexigenic adipokine, whose dysregulation is implicated in diet, and olanzapine-induced obesity through a histamine/AMPK axis in the ARC. Hypothalamic chemerin/CMKLR1 expression is a dynamic time-dependent response to changes in body weight and/or food intake. Targeting chemerin as a novel therapeutic approach against antipsychotic- or diet-induced obesity is worth to be further delineated.

Multi-Probiotic Lactobacillus Supplementation Improves Liver Function and Reduces Cholesterol Levels in Jeju Native Pigs.

Simple SummaryProbiotics are used in the food industry as feed additives to maintain the balance of animal gut microbiota. They are also considered to have potential therapeutic effects against liver diseases. This study showed that dietary Lactobacillus supplementation improved liver function and reduced cholesterol levels in Jeju native pigs, with Toll-like receptors (TLR) signaling as the primary response in the gut against Lactobacillus and TNF-α/IFN-γ as the central mediator cytokines in the gut and liver tissues. Lactobacillus supplementation may be applied to treat metabolic disorders of the liver, especially cholesterol-related disorders, in farm animals.We evaluated the dietary effects of multiple probiotics in Jeju native pigs, using basal diet and multi-probiotic Lactobacillus (basal diet with 1% multi-probiotics) treatments (n = 9 each) for 3 months. We analyzed growth performance, feed efficiency, backfat thickness, blood parameters, hematological profiles, adipokines, and immune-related cytokines in pig tissues. Average daily gain, feed intake, feed efficiency, backfat thickness, and body weight were not significantly different between both groups. In Lactobacillus group, total protein (p < 0.08) and bilirubin (p < 0.03) concentrations increased; blood urea nitrogen (p < 0.08), alkaline phosphatase (p < 0.08), and gamma-glutamyltransferase (p < 0.08) activities decreased. Lactobacillus group showed decreased adiponectin (p < 0.05), chemerin (p < 0.05), and visfatin expression in adipose tissues, and increased TLR4 (p < 0.05), MYD88 (p < 0.05), TNF-α (p < 0.001), and IFN-γ (p < 0.001) expression in the liver. Additionally, NOD1 (p < 0.05), NOD2 (p < 0.01), and MYD88 (p < 0.05) mRNA levels in proximal colon tissue upregulated significantly. Colon, longissimus dorsi muscle, fat tissue, and liver histological analyses revealed no significant differences between the groups. Conclusively, Lactobacillus supplementation improved liver function and reduced cholesterol levels. Its application may treat metabolic liver disorders, especially cholesterol-related disorders.