NCBI Summary:
This gene encodes a secreted chemotactic protein that initiates chemotaxis via the ChemR23 G protein-coupled seven-transmembrane domain ligand. Expression of this gene is upregulated by the synthetic retinoid tazarotene and occurs in a wide variety of tissues. The active protein has several roles, including that as an adipokine and as an antimicrobial protein with activity against bacteria and fungi. [provided by RefSeq, Nov 2014]
General function
Ligand, Cytokine
Comment
Higher levels of circulating chemerin in both lean and obese patients with polycystic ovary syndrome. Ademoglu E et al. (2014) The aim of this paper was to compare serum chemerin levels in nonobese and overweight/obese patients with polycystic ovary syndrome (PCOS) with lean controls. Seventy women with newly diagnosed or untreated PCOS and 38 age-matched nonobese healthy controls were enrolled in the present study. Participants with PCOS were categorized as nonobese (Body Mass Index [BMI] <25 kg/m2, N.=36) or overweight/obese (BMI 25-29.9 kg/m2 and ≥30 kg/m2, respectively, N.=34). Anthropometric, metabolic and hormonal patterns, and serum chemerin were measured. Serum chemerin tended to be higher in obese PCOS group than in nonobese PCOS women but did not reach statistical significance. Nonobese healthy controls had significantly lower chemerin levels than two PCOS groups (P<0.001). Fasting insulin (P<0.05) and homeostasis model assessment index (P<0.05) were significantly higher in obese women with PCOS than in other two groups. Also, these two parameters were higher in lean patients with PCOS than in healthy controls (P<0.05). In multiple linear regression analyses, chemerin was significantly associated with BMI (β-coefficient =0.336, P<0.01), and triglyceride (β-coefficient =0.298, P<0.05). Chemerin levels were significantly increased not only in obese PCOS women but also in nonobese PCOS women. The physiological significance of elevated serum chemerin in PCOS remains unclear.//////////////////
Cellular localization
Secreted
Comment
Increased serum chemerin concentrations in patients with polycystic ovary syndrome: Relationship between insulin resistance and ovarian volume. Huang R et al. (2015)//////////////////
CHEMERIN as a modulator of angiogenesis and apoptosis processes in the corpus luteum of pigs: An in vitro study. Rytelewska E et al. (2021) The corpus luteum (CL) undergoes rapid changes, and its functional capabilities are influenced by processes such as angiogenesis and apoptosis. According to the literature, chemerin - a protein which participates in the regulation of energy homeostasis and the immune response, may also affect angiogenesis and apoptosis. Therefore, the aim of this study was to investigate the in vitro effect of chemerin on angiogenesis and apoptosis in porcine luteal cells (Lc) during specific phases related to CL physiology. Luteal cells were harvested from gilts during the early-, mid-, and late-luteal phases of the estrous cycle. The cells were preincubated for 48 h and incubated for 24 h with chemerin or a serum-free medium (controls). The abundance of angiogenesis- and apoptosis-related proteins was determined by ELISA in spent culture media, or by ELISA and Western Blot in protein extracts. The current study demonstrated that chemerin stimulates the production of VEGF-A and bFGF by porcine Lc and increases the protein abundance of angiogenic factors receptors (VEGFR1, VEGFR2, VEGFR3, FGFR1, FGFR2) in these cells. The study also revealed that chemerin exerts a modulatory effect (stimulatory/inhibitory, depending on the phase of the cycle) on the protein abundance of Fas, FasL, Bcl-2 and caspase-3 in porcine Lc. These results imply that chemerin may affect angiogenesis and apoptosis processes in the porcine CL, as evidenced by its modulatory effect of chemerin on the protein abundance of crucial angiogenesis- and apoptosis-related factors, observed in an in vitro study of porcine Lc.//////////////////Chemerin as a modulator of ovarian steroidogenesis in pigs: an in vitro study. Rytelewska E et al. (2020) Chemerin has been shown to participate in the regulation of ovarian steroidogenesis in women, rats, mice and cows. Even though pigs are one of the most economically important livestock species, there is a general lack of data on the effects of chemerin in this species. Therefore, this study aimed to investigate the in vitro effect of chemerin on basal and luteinizing hormone/follicle-stimulating hormone- and/or insulin-induced secretion of progesterone (P4), androstenedione (A4), testosterone (T), estrone (E1) and estradiol (E2) by the porcine ovarian cells during the estrous cycle and early pregnancy. Granulosa (G) and theca interna (Th) cells were collected from gilts during the follicular phase. Luteal cells (Lc) were harvested from pigs during the early-luteal, mid-luteal and late-luteal phases, as well as during the maternal recognition of pregnancy and beginning of implantation. Cells were preincubated for 24 h (G and Th) or 48 h (Lc) and subsequently incubated for 24 h with or without treatments. Then, the concentrations of steroid hormones in the culture media were determined by radioimmunoassay. The results were analyzed by one-way analysis of variance, followed by Duncan's post hoc test. The study demonstrated that chemerin exerts a modulatory effect on de novo synthesis of steroid hormones in pigs. Chemerin stimulated basal and/or induced secretion of P4 by the porcine Lc during the early-, mid- and late-luteal phases of the estrous cycle, as well as during both studied periods of early pregnancy. Further, chemerin caused an increase in the induced secretion of A4, T and E1 by the porcine Lc during the maternal recognition of pregnancy. Moreover, chemerin inhibited induced secretion of E2 by the porcine Lc during the early-, mid- and late-luteal phases, as well as during the maternal recognition of pregnancy. During the follicular phase, chemerin stimulated basal and induced secretion of P4 and inhibited induced secretion of E2 by the porcine G, as well as decreased induced secretion of A4, and T by the porcine Th. Therefore, chemerin appears to be a modulator of ovarian steroidogenesis in pigs, whereas its varied effects (stimulatory or inhibitory) on the secretion of steroid hormones may be due to the heterogeneity of factors regulating ovarian functions, possible interactions between these factors, and specific processes related to the ovarian physiology during different phases of the estrous cycle/pregnancy. Chemerin may also affect ovarian steroidogenesis in pigs by regulating the expression/activity of steroidogenic enzymes.//////////////////
Transcription Analysis of the Chemerin Impact on Gene Expression Profile in the Luteal Cells of Gilts. Makowczenko KG et al. (2020) Chemerin is a recently discovered adipokine that participates in the regulation of many physiological and disorder-related processes in mammals, including metabolism, inflammatory reactions, obesity, and reproduction. We investigated how chemerin affects the transcriptome profile of porcine luteal cells. The luteal cells were acquired from mature gilts. After the in vitro culturing with and without chemerin, the total RNAs were isolated and high-throughput sequencing was performed. Obtained datasets were processed using bioinformatic tools. The study revealed 509 differentially expressed genes under the chemerin influence. Their products take part in many processes, important for the functions of the corpus luteum, such as steroids and prostaglandins synthesis, NF-κB and JAK/STAT signal transducing pathways, and apoptosis. The expression of the CASP3, HSD3B7, IL1B, and PTGS2 genes, due to their important role in the physiology of the corpus luteum, was validated using the quantitative real-time polymerase chain reaction (qPCR) method. The qPCR confirmed the changes of gene expression. Chemerin in physiological concentrations significantly affects the expression of many genes in luteal cells of pigs, which is likely to result in modification of physiological processes related to reproduction.//////////////////Expression of chemerin and its receptors in the ovaries of prepubertal and mature gilts. Rytelewska E et al. (2020) Recent studies have demonstrated that chemerin participates in the regulation of female reproductive function at the level of the ovaries. Due to the lack of data concerning the presence of the chemerin system (chemerin and its receptors: CMKLR1, GPR1, CCRL2) in the ovaries of pigs, one of the most economically important livestock species, the aim of this study was to investigate the expression and localization of chemerin and its receptors in the ovaries of prepubertal and mature gilts. We also aimed to examine the concentrations of chemerin in the follicular fluid of prepubertal and mature animals. In the present study, we have demonstrated the expression patterns of chemerin system components in the porcine follicles of different sizes of prepubertal and mature animals, as well as in corpora lutea of mature gilts during the estrous cycle and early pregnancy. The obtained results suggest that the expression of chemerin system components is influenced by the reproductive stage, cell type, and the hormonal status of gilts (the estrous cycle/pregnancy). We have also presented the localization of the chemerin system components in various ovarian structures, and also showed changes in the concentration of chemerin in the follicular fluid of pigs. The presented findings not only confirm that chemerin is produced locally in the porcine ovary but they also demonstrate that chemerin directly affects ovarian cells, as confirmed by the presence of chemerin receptors in all ovarian structures. Therefore, chemerin appears to be an important intra-ovarian factor that could regulate ovary function in pigs.//////////////////CHEMERIN (RARRES2) Decreases In Vitro Granulosa Cell Steroidogenesis and Blocks Oocyte Meiotic Progression in Bovine Species. Reverchon M 2014 et al.
CHEMERIN or RARRES2 is a new adipokine that is involved in the regulation of adipogenesis, energy metabolism and inflammation. Recent data suggest that it also plays a role in reproductive function in rats and humans. Here we studied the expression of CHEMERIN and its three receptors (CMKLR1, GPR1 and CCRL2) in the bovine ovary and investigated the in vitro effects of this hormone on granulosa cell steroidogenesis and oocyte maturation. By RT-PCR, immunoblotting and immunohistochemistry, we found CHEMERIN, CMKLR1, GPR1 and CCRL2 in various ovarian cells, including granulosa and theca cells, corpus luteum, and oocytes. In cultured bovine granulosa cells, INSULIN, IGF1 and two insulin sensitizers, metformin and rosiglitazone increased rarres2 mRNA expression whereas they decreased cmklr1, gpr1 and cclr2 mRNA expression. Furthermore, TNF alpha and ADIPONECTIN significantly increased rarres2 and cmklr1 expression, respectively. In cultured bovine granulosa cells, human recombinant CHEMERIN (hRec, 200 ng/ml) reduced production of both progesterone and estradiol, cholesterol content, STAR abundance, CYP19A1 and HMGCR proteins, and the phosphorylation levels of MAPK3/MAPK1 in the presence or absence of FSH (10(-8) M) and IGF1 (10(-8) M). All these effects were abolished by using an anti-CMKLR1 antibody. In bovine cumulus-oocyte complexes, the addition of hRec (200 ng/ml) in the maturation medium arrested most oocytes at the GV stage and this was associated with a decrease in MAPK3/1 phosphorylation in both oocytes and cumulus cells. Thus, in cultured bovine granulosa cells, hRec decreases steroidogenesis, cholesterol synthesis and MAPK3/1 phosphorylation probably through CMKLR1. Moreover, in cumulus-oocyte complexes, it blocked meiotic progression at the germinal vesicle stage and inhibited MAPK3/1 phosphorylation in both the oocytes and cumulus cells during in vitro maturation.
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Chemerin Suppresses Ovarian Follicular Development and Its Potential Involvement in Follicular Arrest in Rats Treated Chronically with Dihydrotestosterone. Young Kim J et al. In the present study, we have investigated the cellular mechanisms of androgen-induced antral follicular growth arrest and the possible involvement of chemerin and its receptor chemokine-like receptor 1 (CMKLR1) in this process, using a chronically androgenized rat model. We hypothesize that hyperandrogenism induces antral follicle growth arrest via the action of chemerin and ovarian structural changes, resulting from granulosa cell and oocyte apoptosis and theca cell survival. Dihydrotestosterone (DHT) treatment resulted in increased expression of chemerin and CMKLR1 in antral follicles, absence of corpus luteum, and increased atypical follicles. Addition of chemerin to follicle cultures induced granulosa cell apoptosis and suppressed basal, FSH- and growth differentiation factor-9-stimulated follicular growth. DHT down-regulated aromatase expression and increased active caspase-3 content and DNA fragmentation in granulosa cells in vivo. These changes were accompanied by higher phosphatase and tensin homolog and lower phospho-Akt (Ser473) content in antral follicles and higher calpain expression and down-regulation of cytoskeletal proteins in atypical follicles, which were constituted predominantly of theca cells. DHT also activated granulosa cell caspase-3, decreased X-linked inhibitor of apoptosis protein, poly(ADP-ribose) polymerase, and phospho-Akt contents and induced apoptosis in vitro, responses readily attenuated by forced X-linked inhibitor of apoptosis protein expression. These findings are consistent with our hypothesis that antral follicular growth arrest in DHT-treated rats results from increased chemerin expression and action, as well as changes in follicular cell fate and structure, which are a consequence of dysregulated interactions of pro-survival and pro-apoptotic modulators in a cell-specific manner. Our observations suggest that this chronically androgenized rat model may be useful for studies on the long-term effects of androgens on folliculogenesis and may have implications for the female reproductive disorders associated with hyperandrogenism.
Chemerin inhibits IGF-1-induced progesterone and estradiol secretion in human granulosa cells. Reverchon M et al. BACKGROUNDChemerin is a novel adipokine involved in the regulation of adipocyte development, inflammation and metabolic functions. To date, no role of this adipokine in reproductive functions has been described. In the present study, we identified chemerin and its receptor, CMKLR1 (chemokine-like receptor 1), in primary human granulosa cells (hGCs) and in a human ovarian granulosa-like tumour cell line (KGN). We also investigated the effects of recombinant human chemerin (rhChem) on steroid production and on various signalling pathways.METHODS AND RESULTSBy RT-PCR immunoblotting and immunohistochemistry, we showed that chemerin and CMKLR1 are expressed in hGCs and KGN cells. By ELISA, we also found chemerin in human follicular fluid and we observed that in 8 of 10 women the chemerin level was at least 2-fold higher in follicular fluid than in plasma. rhChem (10 or 100 ng/ml) significantly decreased insulin-like growth factor-1 (IGF-1) (10(-8) M)-induced secretion of progesterone and estradiol (as determined by radioimmunoassay) but did not affect basal-or FSH (10(-8) M)-induced steroid secretion in hGCs and KGN cells. In parallel, it also decreased IGF-1-induced p450 aromatase protein levels without affecting the protein levels of other factors involved in steroidogenesis (steroidogenic acute regulatory protein, 3-beta-hydroxysteroid dehydrogenase and p450 side-chain cleavage enzyme) in hGCs cells. All these changes were associated with a decrease in the IGF-1-induced tyrosine phosphorylation of IGF-1 receptor beta subunit and phosphorylation of mitogen-activated protein kinase extracellular signal-regulated kinases 1/2 (MAPK ERK1/2) and Akt. In hGCs and KGN cells, rhChem also decreased IGF-1-induced thymidine incorporation. Finally, we showed that rhChem rapidly activates MAPK ERK1/2, MAPK P38 and Akt phosphorylation and more slowly AMP-activated protein kinase phosphorylation under basal conditions (no IGF-1 or FSH) in primary hGC cells.CONCLUSIONSTaken together, chemerin and its receptor (CMKLR1) are present and active in hGCs. Chemerin reduces IGF-1-induced steroidogenesis and cell proliferation through a decrease in the activation of IGF-1R signalling pathways in primary hGCs.
Expression regulated by
Steroids
Comment
Ovarian localization
Oocyte, Granulosa, Luteal cells, Follicular Fluid
Comment
Increased chemerin serum levels in hyperandrogenic and normoandrogenic women from Argentina with polycystic ovary syndrome. Abruzzese GA et al. (2020)Aim: To assess serum chemerin levels and investigate the association of chemerin with the hyperandrogenic and normoandrogenic phenotypes of Polycystic Ovary Syndrome (PCOS) and with the metabolic status of the analyzed population. Material and methods: A cross-sectional study was conducted on 106 women with PCOS and 60 healthy controls from Argentina. Patients were classified as showing a hyperandrogenic or normoandrogenic phenotype. Participants underwent anthropometric and clinical evaluation and markers of cardiovascular risk, insulin resistance, metabolic syndrome (MS), and serum chemerin levels were assessed. Results: PCOS patients showed increased levels of chemerin. In adjusted models for age and body mass index (BMI), chemerin was associated with markers of metabolic status. The analysis of chemerin levels considering the cutoff values of BMI, homeostatic model of insulin sensitivity (HOMA-IR) and TG/HDL marker showed that PCOS patients always presented higher levels of chemerin than controls. PCOS group showed increased chemerin levels independently of the presence of MS. Conclusion: PCOS patients always showed increased levels of chemerin independently of their phenotype and presence of overweight, as well as higher levels of chemerin than controls when considering the cutoff values of HOMA-IR and TG/HDL. Therefore, argentine women with PCOS display increased chemerin levels independently of their metabolic or androgenic status.//////////////////Elevated chemerin induces insulin resistance in human granulosa-lutein cells from polycystic ovary syndrome patients. Li X et al. (2019) The insulin resistance (IR) of 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 role and underlying mechanism of chemerin in developing IR of the granulosa cells from PCOS remain unclear. Plasma, follicular fluid, and human granulosa-lutein cells (hGLs) were collected from non-PCOS and patients with PCOS with or without IR. The chemerin levels were elevated in both follicular fluid and hGL samples from patients with PCOS with IR, and the hGLs from patients with PCOS with IR showed decreased insulin sensitivity and impaired glucose uptake capacity. Moreover, treatment of chemerin attenuated insulin-stimulated glucose uptake by decreasing phosphorylation of insulin receptor substrate (IRS)1/2 Tyr612, phosphorylation of protein kinase B Ser473, and membrane translocation of glucose transporter type 4 through increasing Ser307 phosphorylation of IRS1 in cultured hGLs. These effects could be abolished by small interfering RNA-mediated knockdown of chemokine-like receptor 1. Furthermore, insulin induced the expression of chemerin in hGLs. 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.-Li, X., Zhu, Q., Wang, W., Qi, J., He, Y., Wang, Y., Lu, Y., Wu, H., Ding, Y., Sun, Y. Elevated chemerin induces insulin resistance in human granulosa-lutein cells from polycystic ovary syndrome patients.//////////////////
High concentration of chemerin caused by ovarian hyperandrogenism may lead to poor IVF outcome in polycystic ovary syndrome: a pilot study. Wang Y et al. (2019) A chronic low-grade inflammation state accounts for an important part of the pathogenesis of polycystic ovary syndrome (PCOS). The adipose tissue derived cytokine chemerin has recently been proven to be a proinflammatory chemokine, but its mechanism involved in the pathogenesis of PCOS remains largely unresolved. From non-obese patients with and without PCOS, follicular fluid and granulosa cells were retrieved. The effect of testosterone on the expression of chemerin and its receptors was explored in granulosa cells. IVF outcomes in different groups based on FF-chemerin (chemerin in the follicular fluid) level were further compared. The concentration of FF-chemerin, and the mRNA expression of chemerin and its receptors in granulosa cells from PCOS were significantly higher than those from non-PCOS. FF-chemerin was positively correlative to total testosterone (TT) and luteinizing hormone (LH) in the follicular fluid. Furthermore, testosterone upregulated the expression of chemerin and its receptors in vitro. The oocyte utilization rate and high-quality embryo rate were significantly decreased in the high FF-chemerin group. The upregulated chemerin levels in the ovary of PCOS patients, which may be caused by ovarian hyperandrogenism, may be a risk factor for oocyte maturation and embryo development. These findings may provide a basis for novel interventions to improve IVF outcomes.//////////////////
Inhibitory Roles of Prohibitin and Chemerin in FSH-Induced Rat Granulosa Cell Steroidogenesis. Wang Q et al. Follicular differentiation is a tightly regulated process involving various endocrine, autocrine, and paracrine factors. The biosynthesis of progesterone and estradiol in response to FSH involves the regulation of multiple steroidogenic enzymes, such as p450 cholesterol side-chain cleavage enzyme and aromatase. Here we demonstrated that prohibitin (PHB), a multifunctional protein, inhibits FSH-induced progesterone and estradiol secretion in rat granulosa cells. The mRNA abundances of cyp11a (coding p450 cholesterol side-chain cleavage enzyme) and cyp19 (coding aromatase) were also suppressed by PHB in a time-dependent manner. It is known that a novel adipokine chemerin suppresses FSH-induced steroidogenesis in granulosa cells. Chemerin up-regulates the content of PHB, and PHB knockdown attenuates the suppressive role of chemerin on steroidogenesis. In addition, inhibition of phosphatidylinositol 3-kinase/Akt pathway enhances the suppressive action of PHB, whereas expression of constitutively active Akt attenuates this response. These findings suggest that PHB is a novel negative regulator of FSH-induced steroidogenesis, and its action with chemerin may contribute to the dysregulation of steroidogenesis in the pathogenesis of polycystic ovarian syndrome.
Chemerin, a Novel Regulator of Follicular Steroidogenesis and Its Potential Involvement in Polycystic Ovarian Syndrome. Wang Q et al. Polycystic ovarian syndrome (PCOS) is a heterogeneous syndrome associated with follicle growth arrest, minimal granulosa cell proliferation, dysregulated sex hormone profile, hyperthecosis, and insulin resistance. Using a 5a-dihydrotestosterone (DHT)-induced rat model that recapitulates the reproductive and metabolic phenotypes of human PCOS, we have examined the steroidogenic capability of granulosa cells from DHT-treated rats. Gene expression of several key steroidogenic enzymes including p450 side-chain cleavage enzyme (p450scc), aromatase, steroidogenic acute regulatory protein, hydroxysteroid dehydrogenase-17? and hydroxysteroid dehydrogenase-3?were markedly lower in DHT-treated rats than the controls, although the responsiveness of their granulosa cells to FSH was higher. Expression of the adipokine chemerin and its receptor, chemokine receptor-like 1, was evident in control and DHT-treated rats, with significantly higher ovarian mRNA abundances and protein contents of chemerin and its receptor. Recombinant chemerin decreases basal estradiol secretion in granulosa cells from DHT-treated rats. When the inhibitory role of chemerin on steroidogenesis was further examined in vitro, chemerin suppressed FSH-induced progesterone and estradiol secretion in cultured preantral follicles and granulosa cells. Chemerin also inhibits FSH-induced aromatase and p450scc expression in granulosa cells. Overexpression of nuclear receptors NR5a1 and NR5a2 promotes p450scc and aromatase expression, respectively, which is suppressed by chemerin. These findings suggest that chemerin is a novel negative regulator of FSH-induced follicular steroidogenesis and may contribute to the pathogenesis of PCOS.
Follicle stages
Antral
Comment
Elevated serum chemerin in Chinese women with hyperandrogenic PCOS. Wang L 2014 et al.
Abstract Objectives: To compare serum chemerin levels between women with classic hyperandrogenic PCOS, euandrogenic PCOS and matched control subjects. Research design and methods: This study was carried out at the Second XiangYa Hospital between July 2012 and April 2013. Sixty-seven women with PCOS and 20 controls were included. Blood pressure, body mass index (BMI), waist to hip ratio (WHR), fasting insulin, fasting plasma glucose and blood serum hormone and blood lipid were measured. Transvaginal ultrasound was performed. Serum chemerin was measured by ELISA. Results: Serum chemerin was significantly higher in classic hyperandrogenic PCOS compared with euandrogenic PCOS and controls (311.07???141.87?ng/mL versus 228.03???119.66?ng/mL and 225.87???86.44?ng/mL, p?