NCBI Summary:
This gene encodes a protein which acts as a receptor for adiponectin, a hormone secreted by adipocytes which regulates fatty acid catabolism and glucose levels. Binding of adiponectin to the encoded protein results in activation of an AMP-activated kinase signaling pathway which affects levels of fatty acid oxidation and insulin sensitivity. A pseudogene of this gene is located on chromosome 14. Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Mar 2014]
General function
Receptor
Comment
Cellular localization
Plasma membrane
Comment
Upregulation of adiponectin receptor 1 and 2 mRNA and protein in adipose tissue and adipocytes in insulin-resistant women with polycystic ovary syndrome. Tan BK et al. (2006) Polycystic ovary syndrome (PCOS) is a multifaceted metabolic disease linked with insulin resistance (IR) and obesity. Adiponectin, which is lower in IR states, exerts its glucose-lowering and anti-inflammatory effects by activating two receptors, ADIPOR1 and ADIPOR2. There are no data on the relative expression of these receptors in adipose tissue of PCOS women. We investigated the expression of adiponectin receptors from corresponding s.c. and omental (o.m.) adipose tissue in women with PCOS compared with matched non-PCOS women. As there is a disturbance in the steroid milieu in PCOS women, we also assessed the effects of testosterone and oestradiol on adiponectin receptors using adipocytes and adipocyte explants. Real-time RT-PCR and western blotting were used to assess the relative adiponectin receptor mRNA expression and protein production, respectively. Biochemical measurements were performed in our hospital's laboratory. We are the first to describe adiponectin receptor expression and production, in corresponding s.c. and o.m. human adipose tissues at the mRNA and protein level. We demonstrate the upregulation of mRNA expression and protein production of adiponectin receptors in women with PCOS, in s.c. and o.m. adipose tissue. Treatment of adipose tissue explants and adipocytes with testosterone and oestradiol induced the expression of adiponectin receptor mRNA and protein. There was a significant positive association between ADIPOR1/R2 expression and homeostasis model assessment, testosterone, oestradiol and triglycerides and a negative relationship with sex hormone-binding globulin. The precise reason for the upregulation of adiponectin receptors seen in PCOS women, a pro-diabetic state, is unknown, but it appears that sex steroids may play a role in their regulation in adipose tissue.//////////////////
Ovarian function
Steroid metabolism
Comment
Expression of adiponectin and its receptors (AdipoR1 and AdipoR2) in chicken ovary: Potential role in ovarian steroidogenesis. Chabrolle C et al. Adiponectin and its receptors (AdipoR1 and AdipoR2) mRNAs are expressed in various chicken tissues including ovary. However, the cellular expression and the role of adiponectin system have never been investigated in chicken ovary. Here, we have shown that the level of adiponectin mRNA is about 10- to 30-fold higher (p<0.001) in theca cells than in granulosa cells from each hierarchical yellow follicle studied (F4-F1). In contrast, the level of AdipoR1 mRNA expression was about two-fold lower in theca cells than in granulosa cells (p<0.05) whereas those of AdipoR2 was similar in both ovarian cells. Whereas expression of adiponectin mRNA increased with follicular differentiation in theca cells, it decreased in granulosa cells. In contrast, mRNA expression of AdipoR1 and AdipoR2 in both theca and granulosa cells remained stable during yellow follicle development. To determine whether adiponectin is involved in the ovarian steroidogenesis, LH (100ng/ml)-, FSH (100ng/ml)- and IGF-1 (100ng/ml)-induced progesterone production was measured in absence or presence of human recombinant adiponectin (10mug/ml) for 36h in cultured granulosa cells from F1, F2 and mixed F3 and F4 follicles. In absence of LH, FSH and IGF-1, adiponectin treatment had no effects on progesterone production whatever vitollegenic follicle studied. However, it increased by about two-fold IGF-1-induced progesterone secretion in F2 and F3/4 follicles whereas it halved progesterone production in response to gonadotropins (LH and FSH) in F3/4 follicles. Thus, in chicken, adiponectin, mainly expressed in theca cells, could exert paracrine or autocrine effect on the ovarian steroidogenesis.
Expression regulated by
Comment
ADIPONECTIN INDUCES PERI-OVULATORY CHANGES IN OVARIAN FOLLICULAR CELLS. Ledoux S et al. Adiponectin, the most abundantly synthesized protein in adipose tissue, has plieotropic effects on liver, muscle, endothelium, placenta and other tissues. We examined direct effects of recombinant porcine adiponectin on porcine ovarian granulosa cells in vitro. We demonstrate that adiponectin, at physiologically relevant levels (10-25 microg/ml), provokes expression of genes associated with peri-ovulatory remodeling of the ovarian follicle over a time frame of 6-24 h. These include cyclo-oxygenase-2, prostaglandin E synthase and vascular endothelial growth factor. Adiponectin modulates steroid synthetic protein gene expression, increasing steroidogenic acute regulatory protein transcript abundance while that of reducing cytochrome P450aromatase. Adiponectin has antidiabetic properties, and sensitizes tissues to insulin. We show that it interacts with both LH and insulin in inducing expression of COX-2 transcripts in granulosa cells. We determined that the mitogen-activated protein kinase pathway, via phosphorylation of extracellular receptor kinase 1/2, is involved in mediation of the adiponectin signal in ovarian granulosa cells, rather than protein kinase A or the classic adiponectin transducer, AMP-activated protein kinase. Adiponectin synthesis is reduced in obesity and our findings suggest that this reduction plays a role in obesity-related ovarian dysfunction.
Ovarian localization
Cumulus, Granulosa, Theca
Comment
Expression of adiponectin and its receptors (AdipoR1 and AdipoR2) in goat ovary and its effect on oocyte nuclear maturation in vitro. Oliveira BSP et al. (2017) Adiponectin is an adipokine secreted primarily by adipocytes and is involved in the control of male and female reproductive functions. Circulating levels of adiponectin are inversely correlated with body fat mass, and its biological effects are predominantly mediated through two receptors, AdipoR1 and AdipoR2. The aim of the present study was to verify the expression of the adiponectin system (adiponectin and its receptors, AdipoR1 and AdipoR2) in goat ovary using qPCR and immunohistochemistry analyses and further investigate the in vitro effects of recombinant adiponectin (5 μg/mL and 10 μg/mL) on goat oocyte nuclear maturation. We demonstrated that the mRNA and proteins of the adiponectin system are present in goat ovary. Gene and protein expression of AdipoR1 and AdipoR2 was detected in follicular cells (oocyte, cumulus, granulosa and theca) of small and large antral follicles, while adiponectin mRNA was not detected in oocytes from small and large follicles or in large follicle cumulus cells. Finally, addition of various concentrations of adiponectin in maturation medium affected the number of oocytes that reached metaphase II. In conclusion, in the present study, we detected expression of adiponectin and its receptors AdipoR1 and AdipoR2 in goat ovarian follicles. Furthermore, we demonstrated that recombinant adiponectin increases nuclear maturation of goat oocytes in vitro.//////////////////
Gene expression pattern of adiponectin and adiponectin receptors in dominant and atretic follicles and oocytes screened based on brilliant cresyl blue staining. Tabandeh MR et al. Adiponectin and its receptors (AdipoR1 and AdipoR2) are novel endocrine systems that act at various levels to control male and female fertility. The aim of this study was to determine whether adiponectin and its receptors gene expression levels differ between dominant follicle (DF) and atretic follicle (AF) and also between oocytes which were stained positively and negatively with brilliant cresyl blue (BCB(+) and BCB(-)). Based on estradiol/progesterone ratio, follicles from ovaries were classified as AFs and DFs. The stages of estrous cycle (follicular or luteal phases) were defined by macroscopic observation of the ovaries and the uterus. Oocytes were stained with BCB for 90min. The relative expression of adiponectin, AdipoR1 and AdipoR2 mRNA in theca and cumulus cells and oocytes of different follicles were determined by quantitative real time PCR. Adiponectin and its receptors genes were clearly expressed higher (P<0.05) in theca and cumulus cells and oocytes of DFs than those of AFs during the follicular and luteal phases. BCB(+) oocytes showed a higher (P<0.05) expression of adiponectin and its receptors compared with their BCB(-) counterparts. Positive correlation (r>0.725, P<0.001) was observed between adiponectin mRNA level in ovarian cells of DFs and follicular fluid E2 concentration in follicular phase. Adiponectin mRNA abundance in ovarian cells of AFs showed a significant negative correlation with follicular fluid progesterone concentration in follicular and luteal phases (r<-0.731, P<0.001). This work has revealed the novel association of adiponectin and its receptors genes with follicular dominance and oocyte competence, thereby opening several new avenues of research into the mechanisms of dominance and competence in animal and human.
Molecular cloning and tissue expression of chicken AdipoR1 and AdipoR2 complementary deoxyribonucleic acids. Ramachandran R et al. AdipoR1 and AdipoR2 belong to a novel class of transmembrane receptors that mediate the effects of adiponectin. We have cloned the chicken AdipoR1 and AdipoR2 complementary deoxyribonucleic acids (cDNA) and determined their expression in various tissues. We also investigated the effect of feed deprivation on the expression of AdipoR1 or AdipoR2 mRNA in the chicken diencephalon, liver, anterior pituitary gland, and adipose tissue. The chicken AdipoR1 and AdipoR2 cDNA sequences were 76-83% identical to the respective mammalian sequences. A hydrophobicity analysis of the deduced amino acid sequences of chicken AdipoR1/AdipoR2 revealed seven distinct hydrophobic regions representing seven transmembrane domains. By RT-PCR, we detected AdipoR1 and AdipoR2 mRNA in adipose tissue, liver, anterior pituitary gland, diencephalon, skeletal muscle, kidney, spleen, ovary, and blood. AdipoR1 or AdipoR2 mRNA expression in various tissues was quantified by real-time quantitative PCR, and AdipoR1 mRNA expression was the highest in skeletal muscle, adipose tissue and diencephalon, followed by kidney, ovary, liver, anterior pituitary gland, and spleen. AdipoR2 mRNA expression was the highest in adipose tissue followed by skeletal muscle, liver, ovary, diencephalon, anterior pituitary gland, kidney, and spleen. We also found that a 48h feed deprivation significantly decreased AdipoR1 mRNA quantity in the chicken pituitary gland, while AdipoR2 mRNA quantity was significantly increased in adipose tissue (P<0.05). We conclude that the AdipoR1 and AdipoR2 genes are ubiquitously expressed in chicken tissues and that their expression is altered by feed deprivation in the anterior pituitary gland and adipose tissue.
Role of adiponectin receptors, AdipoR1 and AdipoR2, in the steroidogenesis of the human granulosa tumor cell line, KGN. Pierre P et al. BACKGROUND Adiponectin is involved in the regulation of energy homeostasis and more recently in the reproductive functions. We have previously shown that adiponectin receptors (AdipoR1 and AdipoR2) are expressed in human granulosa cells. However, it remains to be investigated whether both AdipoR1 and AdipoR2 or only one of these receptors serve as the major receptor(s) for adiponectin in human granulosa cells. METHODS The RNA interference (RNAi) technology was used to specifically knockdown the expression of either AdipoR1 or AdipoR2. Progesterone and estradiol levels in the conditioned media were measured by radioimmunoassay, and determination of cell proliferation by tritiated thymidine incorporation. The levels of adiponectin receptors and proteins involved in the steroidogenesis and in the signalling pathways were examined by western blot. RESULTS We generated AdipoR1 (R1) and AdipoR2 (R2) knockdown KGN cell lines. R1 cells were apoptotic and had increased expression levels of cleaved caspase 3 and decreased levels of BAD phosphorylation and PCNA as compared with control or parental KGN cells. R2 cells had similar morphology to control or KGN cells. However, they produced less progesterone and estradiol and expressed lower levels of StAR protein in response to FSH or IGF-1 stimulation compared with control cells. Furthermore, the increase of MAPK ERK1/2 phosphorylation in response to human recombinant adiponectin and FSH was lower in R2 than control cells. CONCLUSIONS In the human granulosa KGN cell-line, AdipoR1 seems to be involved in the cell survival whereas AdipoR2, through MAPK ERK1/2 activation, may be implicated in the regulation of steroid production.
Follicle stages
Preovulatory, Corpus luteum
Comment
Changes in the gene expression of adiponectin and adiponectin receptors (AdipoR1 and AdipoR2) in ovarian follicular cells of dairy cow at different stages of development. Tabandeh MR et al. Adiponectin is one of the most important, recently discovered adipocytokines that acts at various levels to control male and female fertility through central effects on the hypothalamus-pituitary axis or through peripheral effects on the ovary, uterus, and embryo. We studied simultaneous changes in the gene expression pattern of adiponectin and adiponectin receptors 1 and 2 (AdipoR1 and AdipoR2) in granulosa and theca cells, cumulus-oocyte complex, and in corpus luteum in healthy bovine (Bos tarus) follicles at different stages of development. The expression levels of adiponectin, AdipoR1, and AdipoR2 mRNA were lower (P<0.05) in granulosa and cumulus cells in comparison with that in theca cells and oocyte. In contrast with the oocyte, AdipoR1 in granulosa, theca, and luteal cells was expressed (P<0.05) more than AdipoR2. Adiponectin expression increased (P<0.05) in granulosa cells and in cumulus-oocyte complex during follicular development from small to large follicles. Opposite results were observed in theca cells. Expression of adiponectin was highest in the late stages of corpus luteum (CL) regression, whereas lower expression was recorded in active CL (P<0.05). AdipoR1 and AdipoR2 expression increased during the terminal follicular growth in granulosa and theca cells (P<0.05) and during the luteal phase progress in CL. There was positive correlation between adiponectin mRNA level in granulosa cells from large follicles and follicular fluid estradiol concentration (r=0.48, P<0.05) and negative correlation between adiponectin mRNA abundance in theca cells and follicular fluid progesterone concentration (r=-0.44, P<0.05). In conclusion, we found that the physiologic status of the ovary has significant effects on the natural expression patterns of adiponectin and its receptors in follicular and luteal cells of bovine ovary.