BACKGROUND

Indomethacin is a nonsteroidal anti-inflammatory drug, which is known to produce serious side effects, causing ulcerative lesions. <em>Nesfatin</em>-<em>1</em>, a newly identified anorexigenic peptide, was recently shown to have neuroprotective effects. The aim of the study was to investigate the anti-inflammatory effects of <em>nesfatin</em>-<em>1</em> on indomethacin-induced gastric ulcer.

METHODS

After a 24-h starvation period, ulcer was induced in Sprague-Dawley rats by subcutaneous administration of indomethacin (25 mg/kg), whereas control group received vehicle. Fifteen minutes after ulcer induction, rats were treated with either saline or <em>nesfatin</em>-<em>1</em> (0.<em>1</em>, 0.3, or <em>1</em> μg/kg, intraperitoneally). At the fourth hour, all rats were decapitated and their trunk blood was collected for tumor necrosis factor (TNF)-α and interleukin (IL)-6 measurements. Stomach samples were examined microscopically and analyzed for myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH), luminol-, and lucigenin-enhanced chemiluminescence (CL) levels.

RESULTS

Ulcer induction increased serum TNF-α; and IL-6 levels, gastric CL and MDA levels and MPO activity but decreased gastric GSH content (P < 0.05-0.00<em>1</em>). On the other hand, 0.<em>1</em> μg/kg dose of <em>nesfatin</em>-<em>1</em> reduced microscopic and macroscopic damage scores, decreased MPO activity and MDA levels, CL and IL-6 levels, whereas gastric GSH was replenished (P < 0.0<em>1</em>). However, indomethacin-induced increase in TNF-α level was abolished at only <em>1</em> μg/kg dose of <em>nesfatin</em>-<em>1</em> (P < 0.0<em>1</em>).

CONCLUSIONS

<em>Nesfatin</em>-<em>1</em> alleviated indomethacin-induced gastric injury, suggesting that the anti-inflammatory and gastroprotective effects of <em>nesfatin</em>-<em>1</em> on oxidative gastric damage could be implemented by supporting the balance in oxidant and antioxidant systems while inhibiting the generation of pro-inflammatory mediators.

<em>Nesfatin</em>-<em>1</em> is a novel anorexic peptide that reduces the food intake of rodents when administered either intraventricularly or intraperitoneally. However, the molecular mechanism of intracellular signaling via <em>Nesfatin</em>-<em>1</em> is yet to be resolved. In the current study, we investigated the ability of different neuronal cell lines to respond to <em>Nesfatin</em>-<em>1</em> and further elucidated the signal transduction pathway of <em>Nesfatin</em>-<em>1</em>. To achieve this, we transfected several cell lines with various combinations of reporter vectors containing different kinds of response elements and performed reporter assays with <em>Nesfatin</em>-<em>1</em>, its active midsegment encoding 30 amino acid residues (M30) and M30-derived mutants. Notably, we found that both <em>Nesfatin</em>-<em>1</em> as well as M30, significantly increased cAMP response element (CRE) reporter activity in a mouse neuroblastoma cell line, NB4<em>1</em>A3. An antagonist of Melanocortin 3/4 receptor, SHU9<em>1</em><em>1</em>9, aborted the promoter activity, and a mutant M30, which exerts no anorexic effect in vivo did not induce the CRE reporter activity in NB4<em>1</em>A3 cells. Western blotting analyses revealed that <em>Nesfatin</em>-<em>1</em> and M30 significantly increased the phosphorylation levels of CRE-binding protein (CREB), without altering the intracellular cAMP levels. Further, our study showed that a mitogen-activated protein kinase (MAPK) kinase inhibitor and an L-type Calcium (Ca(2+)) channel blocker abolished the M30-induced CREB phosphorylation. Furthermore, the radio-receptor assay revealed that (<em>1</em>25)I-<em>Nesfatin</em>-<em>1</em> binds in a saturable fashion to the membrane fractions of the mouse hypothalamus and NB4<em>1</em>A3 cells, with Kd values of 0.79 nM and 0.<em>1</em>7 nM, respectively. Collectively, our findings indicate the presence of a <em>Nesfatin</em>-<em>1</em>-specific receptor on the cell surface of NB4<em>1</em>A3 cells and mouse hypothalamus. Our study highlights that <em>Nesfatin</em>-<em>1</em>, via its receptor, induces the phosphorylation of CREB, thus activating the intracellular signaling cascade in neurons.

<em>Nesfatin</em>-<em>1</em> belongs to a family of anorexigenic peptides, which are responsible for satiety and are identified in the neurons and endocrine cells within the gut. These peptides have been implicated in the control of food intake; however, very little is known concerning its contribution to gastric secretion and gastric mucosal integrity. In this study the effects of <em>nesfatin</em>-<em>1</em> on gastric secretion and gastric lesions induced in rats by 3.5h of water immersion and restraint stress (WRS) were determined. Exogenous <em>nesfatin</em>-<em>1</em> (5-40μg/kg i.p.) significantly decreased gastric acid secretion and attenuated gastric lesions induced by WRS, and this was accompanied by a significant rise in plasma NUCB2/nefatin-<em>1</em> levels, the gastric mucosal blood flow (GBF), luminal NO concentration, generation of PGE2 in the gastric mucosa, an overexpression of mRNA for NUBC2 and cNOS, as well as a suppression of iNOS and proinflammatory cytokine IL-<em>1</em>β and TNF-α mRNAs. <em>Nesfatin</em>-<em>1</em>-induced protection was attenuated by suppression of COX-<em>1</em> and COX-2 activity, the inhibition of NOS with L-NNA, the deactivation of afferent nerves with neurotoxic doses of capsaicin, and the pretreatment with capsazepine to inhibit vanilloid VR<em>1</em> receptors. This study shows for the first time that <em>nesfatin</em>-<em>1</em> exerts a potent protective action in the stomach of rats exposed to WRS and these effects depend upon decrease in gastric secretion, hyperemia mediated by COX-PG and NOS-NO systems, the activation of vagal and sensory nerves and vanilloid receptors.

<em>Nesfatin</em>-<em>1</em>, an 82-amino-acid peptide derived from a 396-amino-acid precursor protein nucleobindin 2 (NUCB2), was originally identified in hypothalamic nuclei involved in the regulation of food intake. It was recently reported that <em>nesfatin</em>-<em>1</em> is a novel depot specific adipokine preferentially produced by subcutaneous tissue, with obesity- and food deprivation-regulated expression. Although a relation between ovarian cancer mortality and obesity has been previously established, a role of <em>nesfatin</em>-<em>1</em> in ovarian epithelial carcinoma remains unknown. The aim of the present study is to examine the effect of <em>nesfatin</em>-<em>1</em> on ovary carcinoma cells proliferation. We found that <em>nesfatin</em>-<em>1</em> inhibits the proliferation and growth of HO-89<em>1</em>0 cells by G<em>1</em> phase arrest, this inhibition could be abolished by <em>nesfatin</em>-<em>1</em> neutralizing antibody. <em>Nesfatin</em>-<em>1</em> enhances HO-89<em>1</em>0 cell apoptosis, activation of mammalian target of rapamycin (mTOR) and RhoA/ROCK signaling pathway block the effects of <em>nesfatin</em>-<em>1</em>-induced apoptosis, therefore reverses the inhibition of HO-89<em>1</em>0 cell proliferation by <em>nesfatin</em>-<em>1</em>. In conclusion, the present study demonstrated that <em>nesfatin</em>-<em>1</em> can inhibit the proliferation in human ovarian epithelial carcinoma cell line HO-89<em>1</em>0 cells through inducing apoptosis via mTOR and RhoA/ROCK signaling pathway. This study provides a novel regulatory signaling pathway of <em>nesfatin</em>-<em>1</em>-regulated ovarian epithelial carcinoma growth and may contribute to ovarian cancer prevention and therapy, especially in obese patients.

<em>Nesfatin</em>-<em>1</em> was discovered in 2006 and implicated in the regulation of food intake. Subsequently, its widespread central and peripheral distribution gave rise to additional effects. Indeed, a multitude of actions were described, including modulation of gastrointestinal functions, glucose and lipid metabolism, thermogenesis, mediation of anxiety and depression, as well as cardiovascular and reproductive functions. Recent years have witnessed a great increase in our knowledge of these effects and their underlying mechanisms, which will be discussed in the present review. Lastly, gaps in knowledge will be highlighted to foster further studies.

OBJECTIVE

Energy homeostasis results from a balance of food intake and energy expenditure, accomplished by the interaction of peripheral and central nervous signals. The recently discovered adipokine <em>nesfatin</em>-<em>1</em> is involved in the central control of food intake, but whether it also participates in the regulation of thermogenesis is unknown.

METHODS

Nesfatin-<em>1</em> was administered intracerebroventricularly to freely moving, male Wistar rats and direct calorimetry was performed to assess its effects on thermogenesis. Furthermore, food intake was measured and hypothalamic and N. tractus solitarius (NTS) neuropeptide expression was determined by quantitative real-time polymerace chain reaction. Leptin, which is involved in both the regulation of food intake and thermogenesis, was used as positive control.

RESULTS

For the first time it was shown that central nervous administration of <em>nesfatin</em>-<em>1</em> profoundly increases thermogenesis in rats to a similar extent as leptin and the role of both peptides in the control of food intake was confirmed. Nesfatin-<em>1</em> significantly downregulated neuropeptide Y (NPY) mRNA expression in both hypothalamus and NTS.

CONCLUSIONS

The results strongly support the prominent role of <em>nesfatin</em>-<em>1</em> for both energy expenditure and food intake and NPY neurons appear to be involved in this effect.

The protein nucleobindin-2 (NUCB2) was identified over a decade ago and recently raised great interest as its derived peptide <em>nesfatin</em>-<em>1</em> was shown to reduce food intake and body weight in rodents. However, the involvement of NUCB2 in feeding behavior has not well been studied in fish. In the present study, we characterized the structure, distribution, and meal responsive of NUCB2A/<em>nesfatin</em>-<em>1</em> in Ya-fish (Schizothorax prenanti) for the first time. The full length cDNA of Ya-fish was 2<em>1</em>40base pair (bp), which encoded a polypeptide of 487 amino acid residues including a 23 amino acid signal peptide. A high conservation in NUCB2 sequences was found in vertebrates, however the proposed propeptide cleavage site (Arg-Arg) conserved among other species is not present in Ya-fish NUCB2A sequence. Tissue distribution analysis revealed that Ya-fish NUCB2A mRNA was ubiquitously expressed in all test tissues, and abundant expression was detected in several regions including the hypothalamus, hepatopancreas, ovary and intestines. NUCB2A mRNA expression respond to feeding status change may vary and be tissue specific. NUCB2A mRNA levels significantly increased (P<0.05) in the hypothalamus and intestines after feeding and substantially decreased (P<0.0<em>1</em>) during a week food deprivation in the hypothalamus. Meanwhile, NUCB2A mRNA in the hepatopancreas was significantly elevated (P<0.00<em>1</em>) during food deprivation, and a similar increase was also found after short-time fasting. This points toward a potential hepatopancreas specific local role for NUCB2A in the regulation of metabolism during food deprivation. Collectively, these results provide the molecular and functional evidence to support potential anorectic and metabolic roles for NUCB2A in Ya-fish.

Gastric and adipose tissue secrete a number of hormones that are involved in energy metabolism. The biological functions of these hormones, including their effects on aging, are currently under investigation. Adiponectin was shown to be directly involved in appetite and the control of body weight. However, the effects of aging of <em>nesfatin</em>-<em>1</em>, an appetite-suppressing peptide that was recently identified, have not yet been fully elucidated. The aim of this study was to determine the effects of aging on the plasma levels of <em>nesfatin</em>-<em>1</em> and adiponectin. Our results demonstrated no significant differences in the <em>nesfatin</em>-<em>1</em> plasma levels among three age groups (2, 6 and 24 months) of female BALB/c mice. The plasma <em>nesfatin</em>-<em>1</em> levels/visceral fat (VF) ratio in the 24-month-old mice was significantly lower compared to that in the 2- and 6-month-old mice. In addition, there were no significant differences in the plasma adiponectin levels among the three age groups. The plasma adiponectin levels/VF ratio in the 24-month-old mice was significantly lower compared to that in the 2- and 6-month-old mice. In conclusion, there were no age-related changes in the plasma levels of <em>nesfatin</em>-<em>1</em> and adiponectin, although the ratio of plasma levels of <em>nesfatin</em>-<em>1</em> and adiponectin per VF was decreased with advancing age. Our results indicated that <em>nesfatin</em>-<em>1</em> and adiponectin may be involved in controlling energy balance during aging.

<em>Nesfatin</em>-<em>1</em>, which originates from its precursor protein nucleobindin-2 (NUCB2), is a novel appetite-regulating molecule that might be associated with the melanocortin signalling pathway in the hypothalamus. The secreted protein appears to play an important role in metabolic control through its anorexigenic and anti-hyperglycemic effects. Therefore, we hypothesized that polymorphisms in the NUCB2 gene might influence the susceptibility for the development of obesity. In this study, we investigated the association of NUCB2 polymorphisms with the development of obesity in an extensive Caucasian population comprising <em>1</em>049 obese subjects and 3<em>1</em>5 normal weight control individuals. We selected 8 tagSNPs, which after additional analysis of 6 multi-marker tests, cover most information on common genetic variation in the selected region. We found association with obesity for 3 SNPs (rs<em>1</em>330, rs2<em>1</em>4<em>1</em>0<em>1</em> and rs75708<em>1</em>) and 3 multi-marker tests, only when analyzing the male population separately. We subsequently performed linear regression analysis, again in the male population only, and found that several SNPs were associated with BMI, weight and fat free mass. These data indicate that polymorphisms in the NUCB2 gene could play an important role in the protection against the development of obesity in male subjects and might have an influence on energy homeostasis. Nevertheless, further research including replication of our results and elucidation of the molecular mechanism remains necessary.

OBJECTIVE

Consumption of high-fat foods is one of the major causes of obesity. Physical exercise is a strategy used to counteract obesity. The aim of this study was to investigate the effect of eight weeks endurance training and high-fat diet (HFD) on appetite-regulating hormones in rat plasma.

METHODS

TWENTY EIGHT MALE WISTAR RATS WERE RANDOMLY DIVIDED INTO FOUR GROUPS: Control group with standard diet (CSD), endurance training with a standard diet (ESD), control group with high-fat diet (CHFD) and endurance training with high-fat diet (EHFD). Twenty-four hr after the last training session, the blood samples were obtained and analyzed for hormones levels.

RESULTS

The significant increased weight gain and food intake and decreased plasma <em>nesfatin</em>-<em>1</em> and PYY3-36 levels were observed in CHFD group, while exercise under the HFD antagonized these effects. There were no significant changes in ghrelin, insulin and leptin levels in different groups.

CONCLUSIONS

These results suggest that exercise can prevent fattening effect of HFD. Probably, performing exercise makes a reduction of food intake and weight gain in rat via the increase in <em>nesfatin</em>-<em>1</em> and PYY levels. However, further studies are necessary to understand the exact mechanisms involved in this field.

<em>Nesfatin</em>-<em>1</em> is derived from nucleobindin2 (NUCB2) and implicated in the regulation of food intake and body weight. Plasma levels are altered under conditions of chronically altered body weight such as obesity. <em>Nesfatin</em>-<em>1</em> was also shown to be involved in the modulation of emotion. Since obesity is often associated with anxiety and depression we investigated plasma NUCB2/<em>nesfatin</em>-<em>1</em> levels in obese women (n=77) over a broad range of body mass index (BMI, 32-67 kg/m(2)) with different levels of anxiety assessed by the generalized anxiety disorder questionnaire (GAD-7). Stress was assessed using the perceived stress questionnaire (PSQ-20) and depression using the patient health questionnaire (PHQ-9). The study population was divided in patients with low anxiety (n=40, GAD scores, mean ± SD, 5.0 ± 2.7) and high anxiety (n=37, <em>1</em>4.2 ± 3.3, p<0.00<em>1</em>). Patients with high anxiety showed higher levels of NUCB2/<em>nesfatin</em>-<em>1</em> (+33%), perceived stress (+60%) and depression (+98%) compared to the low anxiety group (p<0.00<em>1</em>). NUCB2/<em>nesfatin</em>-<em>1</em> levels positively correlated with GAD-7 (r=0.68, p<0.00<em>1</em>), total PSQ-20 (r=0.57, p<0.00<em>1</em>) and PHQ-9 scores (r=0.45, p<0.00<em>1</em>), while no significant correlation was observed with BMI (r=-0.2<em>1</em>, p=0.09). Also the subscales of the PSQ-20, "worries", "tension" and "demands" were higher in the high anxiety group and correlated positively with NUCB2/<em>nesfatin</em>-<em>1</em> (p<0.00<em>1</em>), whereas "joy" was lower and correlated negatively with NUCB2/<em>nesfatin</em>-<em>1</em> (p=0.0<em>1</em>5). Summarized, plasma NUCB2/<em>nesfatin</em>-<em>1</em> levels were altered under conditions of perceived anxiety, stress and depression in obese women. No correlation was observed with BMI. These data point toward an involvement of NUCB2/<em>nesfatin</em>-<em>1</em> in the regulation of emotion in addition to its impact on body weight.

OBJECTIVE

Recent evidences suggest that inflammation is involved in the mechanism of obstructive sleep apnea syndrome (OSAS). <em>Nesfatin</em>-<em>1</em>, recently identified as the satiety regulator, is implicated to possess an anti-inflammatory effect. The aim of our study is to investigate whether serum levels of <em>nesfatin</em>-<em>1</em> are associated with the presence and severity of OSAS.

METHODS

A total of <em>1</em>96 patients with OSAS and <em>1</em>04 healthy subjects were enrolled in this study. Serum levels of <em>nesfatin</em>-<em>1</em> were measured by enzyme-linked immunosorbent assay.

RESULTS

OSAS patients showed significantly reduced levels of serum <em>nesfatin</em>-<em>1</em> levels than healthy controls. Multivariable logistic regression analysis indicates that serum <em>nesfatin</em>-<em>1</em> levels were inversely associated with the presence of OSAS (odds ration (OR) 0.003, 95% confidence interval (CI) 0.00<em>1</em> to 0.0<em>1</em>7; P < 0.00<em>1</em>). Serum levels of <em>nesfatin</em>-<em>1</em> were significantly decreased in severe OSAS patients compared with mild and moderate OSAS patients. Spearman correlation analysis showed that serum <em>nesfatin</em>-<em>1</em> levels were inversely correlated with the severity of OSAS. In addition, Spearman correlation analysis showed that serum <em>nesfatin</em>-<em>1</em> levels were negatively correlated with body mass index (BMI) (r = -0.299, P < 0.00<em>1</em>), waist-hip ratio (WHR) (r = -0.277, P < 0.00<em>1</em>), homeostasis model assessment of insulin resistance (HOMA-IR) (r = -0.338, P < 0.00<em>1</em>), and apnea-hypopnea index (AHI) (r = -0.248, P < 0.00<em>1</em>) in patients with OSAS.

CONCLUSIONS

Decreased serum <em>nesfatin</em>-<em>1</em> levels are associated with the presence and severity of OSAS.

The aim of this study was to investigate for the first time <em>nesfatin</em>-<em>1</em>-like immunoreactive (LI) cells in the mucosal layer of the canine digestive tract. Distribution of <em>nesfatin</em>-<em>1</em> - LI cell bodies and the co-localization of <em>nesfatin</em>-<em>1</em> with somatostatin (SOM), cocaine-and amphetamine-regulated transcript peptide (CART), protein gene product 9.5 (PGP 9.5) and vasoactive intestinal peptide (VIP) were studied by immunohistochemistry in the selected parts of the canine digestive tract. Evaluation of the <em>nesfatin</em> <em>1</em>-LI cells number has been based on the counting of cell bodies per observation field. <em>Nesfatin</em>-<em>1</em>-LI cells amounted to 0.87±0.06, <em>1</em>.06±0.02, 0.85±0.<em>1</em><em>1</em> and 0.56±0.<em>1</em>3 in gastric fundus, duodenum, jejunum and descending colon, respectively. The co-localization of <em>nesfatin</em>-<em>1</em> with the other substances studied was not observed. Functions of <em>nesfatin</em>-<em>1</em> - LI cells in the canine digestive tract are unknown.

<em>Nesfatin</em>-<em>1</em> is a recently discovered satiety-inducing adipokine identified in hypothalamic regions that regulates energy balance. So far, no data exist on NUCB2/<em>nesfatin</em>-<em>1</em> localization in human and murine chondrocytes. Here, we therefore investigated NUCB2/<em>nesfatin</em>-<em>1</em> gene and protein expression in human and murine chondrocytes and the effect of <em>nesfatin</em>-<em>1</em> on pro-inflammatory cytokines expression. Peptide localization was performed by laser confocal microscopy, NUCB2 mRNA expression was studied by RT-PCR and protein secretion was measured by XMap technology and Western blot analysis. First, we demonstrated cytoplasmic localization of NUCB2/<em>nesfatin</em>-<em>1</em> peptide in both human and murine chondrocytes. We present evidence that both mRNA and protein expression of NUCB2 were increased during the differentiation of ATDC5 murine chondrocyte cell line. Furthermore, we demonstrated that <em>nesfatin</em>-<em>1</em> induces IL-6 and MIP-<em>1</em>α mRNA expression and protein secretion in ATDC-5 cells challenged with IL-<em>1</em>, and also increases COX-2 mRNA expression in these cells. Finally, <em>nesfatin</em>-<em>1</em> provoked a clear induction of pro-inflammatory agents, such as COX-2, IL-8, IL-6, and MIP-<em>1</em>α in human primary chondrocytes from OA patients.

<em>Nesfatin</em>-<em>1</em>, a satiety-inducing peptide identified in hypothalamic regions that regulate energy balance, is an integral regulator of energy homeostasis and a putative glucose-dependent insulin coadjuvant. We investigated its production by human cardiomyocytes and its effects on glucose uptake, in the main cardiac glucose transporter GLUT-4 and in intracellular signaling. Quantitative RT-PCR, Western blots, confocal immunofluorescence microscopy, and ELISA of human and murine cardiomyocytes and/or cardiac tissue showed that cardiomyocytes can synthesize and secrete <em>nesfatin</em>-<em>1</em>. Confocal microscopy of cultured cardiomyocytes after GLUT-4 labeling showed that <em>nesfatin</em>-<em>1</em> mobilizes this glucose transporter to cell peripherals. The rate of 2-deoxy-D-[(3)H]glucose incorporation demonstrated that <em>nesfatin</em>-<em>1</em> induces glucose uptake by HL-<em>1</em> cells and cultured cardiomyocytes. <em>Nesfatin</em>-<em>1</em> induced dose- and time-dependent increases in the phosphorylation of ERK<em>1</em>/2, AKT, and AS<em>1</em>60. In murine and human cardiac tissue, <em>nesfatin</em>-<em>1</em> levels varied with diet and coronary health. In conclusion, human and murine cardiomyocytes can synthesize and secrete <em>nesfatin</em>-<em>1</em>, which is able to induce glucose uptake and the mobilization of the glucose transporter GLUT-4 in these cells. <em>Nesfatin</em>-<em>1</em> cardiac levels are regulated by diet and coronary health.

<em>Nesfatin</em>-<em>1</em>, a newly discovered satiety peptide, has recently been reported to be involved in the stress response. Stress-induced expression of <em>nesfatin</em>-<em>1</em> has been reported and few studies focus on its expression in the hypothalamus, which is the center of the stress response. To test our hypothesis that peripheral and hypothalamic <em>nesfatin</em>-<em>1</em> overexpression should play an important role in the stress response and the associated hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis, acute stress (AS) was induced using water avoidance stress (WAS), and chronic unpredictable mild stress (CUMS) was also induced using 3 consecutive weeks of 7 different stressors. The behavior of CUMS rats was evaluated by an open field test (OFT), sucrose preference test (SPT), and forced swimming test (FST). The activity of the HPA axis was detected by measurement of the plasma corticosterone concentration and hypothalamic mRNA expression of corticotropin-releasing-hormone (CRH). The plasma concentration and hypothalamic mRNA expression of <em>nesfatin</em>-<em>1</em> were measured with an enzyme-linked immunosorbent assay (ELISA) and real-time fluorescent quantitative PCR, respectively. The results showed that both AS and CUMS increased the plasma corticosterone concentration and hypothalamic CRH mRNA expression. Depression-like behavior was induced in CUMS rats, as indicated by a decreased movement distance, frequency of rearing and grooming in the OFT, and sucrose preference index and increased immobility in the FST. Moreover, the AS rats showed increased plasma concentration and hypothalamic mRNA expression of <em>nesfatin</em>-<em>1</em>, which were positively correlated with the plasma corticosterone concentration and hypothalamic CRH expression, respectively. These results indicated that acute stress, but not chronic stress, increased the plasma concentration and hypothalamic mRNA expression of NUCB2/<em>nesfatin</em>-<em>1</em> in rats.

OBJECTIVE

To determine the difference of serum levels of <em>1</em>0 adipokines (apelin, chemerin, fatty acid-binding protein-4, fibroblast growth factor-2<em>1</em>, monocyte chemoattractant protein-<em>1</em>, <em>nesfatin</em>-<em>1</em>, omentin-<em>1</em>, resistin, vaspin, and visfatin) among women with gestational diabetes and healthy pregnant controls.

METHODS

Literature search was conducted using the Medline (<em>1</em>966-20<em>1</em>8), Scopus (2004-20<em>1</em>8), Cochrane Central Register of Controlled Trials (CENTRAL) (<em>1</em>999-20<em>1</em>8), Clinicaltrials.gov (2008-20<em>1</em>8) and Google Scholar (2004-20<em>1</em>8) databases, along with the reference list of the included studies.

RESULTS

Ninety-one studies were included in the present review, with a total number of <em>1</em><em>1</em>,074 pregnant women. A meta-analysis was not conducted due to the high inter-study heterogeneity. Current evidence suggests that fatty acid-binding protein-4 levels are significantly increased in pregnancies complicated with gestational diabetes, while no association of serum apelin and monocyte chemoattractant protein-<em>1</em> with the disease can be supported. Data regarding the rest adipokines are conflicting, since the available studies did not unanimously indicate a significant change of their levels in gestational diabetes.

CONCLUSIONS

The findings of the present systematic review suggest the promising role of fatty acid-binding protein-4 in the prediction of gestational diabetes, while inconsistent evidence exists regarding the rest novel adipokines. Future cohorts are needed to assess their predictive efficacy and fully elucidate their contribution in the disease.

<em>Nesfatin</em>-<em>1</em> has been discovered a decade ago and since then drawn a lot of attention. The initially proposed anorexigenic effect was followed by the description of several other involvements such as a role in gastrointestinal motility, glucose homeostasis, cardiovascular functions and thermoregulation giving rise to a pleiotropic action of this peptide. The recent years witnessed mounting evidence on the involvement of <em>nesfatin</em>-<em>1</em> in emotional processes as well. The present review will describe the peptide's relations to anxiety, depressiveness and stress in animal models and humans and also discuss existing gaps in knowledge in order to stimulate further research.

Depression is a multicausal disorder and has been associated with metabolism regulation and immuno-inflammatory reaction. The anorectic molecule <em>nesfatin</em>-<em>1</em> has recently been characterized as a potential mood regulator, but its precise effect on depression and the possible mechanisms remain unknown, especially when given peripherally. In the present study, <em>nesfatin</em>-<em>1</em> was intraperitoneally injected to the rats and the depression-like behavior and activity of the hypothalamic-pituitary-adrenal (HPA) axis were evaluated. The plasma concentrations of <em>nesfatin</em>-<em>1</em>, interleukin 6 (IL-6), and C-reactive protein (CRP); and the hypothalamic expression levels of <em>nesfatin</em>-<em>1</em>, synapsin I, and synaptotagmin I mRNA were evaluated in <em>nesfatin</em>-<em>1</em> chronically treated rats. The results showed that both acute and chronic administration of <em>nesfatin</em>-<em>1</em> increased immobility in the forced swimming test (FST), and resulted in the hyperactivity of HPA axis, as indicated by the increase of plasma corticosterone concentration and hypothalamic expression of corticotropin-releasing hormone (CRH) mRNA. Moreover, after chronic <em>nesfatin</em>-<em>1</em> administration, the rats exhibited decreased activity and exploratory behavior in the open field test (OFT) and increased mRNA expression of synapsin I and synaptotagmin I in the hypothalamus. Furthermore, chronic administration of <em>nesfatin</em>-<em>1</em> elevated plasma concentrations of IL-6 and CRP, which were positively correlated with despair behavior, plasma corticosterone level, and the hypothalamic mRNA expression of synapsin I and synaptotagmin I. These results indicated that exogenous <em>nesfatin</em>-<em>1</em> could induce the immune-inflammatory activation, which might be a central hug linking the depression-like behavior and the imbalanced mRNA expression of synaptic vesicle proteins in the hypothalamus.

The role of <em>nesfatin</em>-<em>1</em> in glucose homeostasis has been investigated previously. However, although numerous studies have examined the relationships between circulating <em>nesfatin</em>-<em>1</em> levels and type 2 diabetes, the conclusions are contradictory. We aimed to probe the relationship between circulating <em>nesfatin</em>-<em>1</em> levels and type 2 diabetes by meta-analysis. Seven studies including 328 type 2 diabetes patients and 294 control subjects were included. Although there was no obvious difference in circulating <em>nesfatin</em>-<em>1</em> levels between patients with type 2 diabetes and the control group (MD = -0.04; 95% CI = -0.32 to -0.23), subgroup analysis showed higher <em>nesfatin</em>-<em>1</em> levels in newly diagnosed type 2 diabetes patients (MD = 0.59; 95% CI = 0.45 to 0.74) and significantly lower <em>nesfatin</em>-<em>1</em> levels in type 2 diabetes patients receiving antidiabetic treatment (MD = -0.26; 95% CI = -0.33 to -0.20). In conclusion, the analysis supports a relationship between circulating <em>nesfatin</em>-<em>1</em> levels and type 2 diabetes, where newly diagnosed type 2 diabetes was associated with an elevated <em>Nesfatin</em>-<em>1</em> level, and type 2 diabetes patients receiving antidiabetic treatment showed lower circulating <em>nesfatin</em>-<em>1</em> levels.

<em>Nesfatin</em>-<em>1</em> was identified in 2006 as a potent anorexigenic peptide involved in the regulation of homeostatic feeding. It is processed from the precursor-peptide NEFA/nucleobindin 2 (NUCB2), which is expressed both in the central nervous system as well as in the periphery, from where it can access the brain via non-saturable transmembrane diffusion. In hypothalamus and brainstem, <em>nesfatin</em>-<em>1</em> recruits the oxytocin, the melancortin and other systems to relay its anorexigenic properties. NUCB2/<em>nesfatin</em>-<em>1</em> peptide expression in reward-related areas suggests that <em>nesfatin</em>-<em>1</em> might also be involved in hedonic feeding. Besides its initially discovered anorexigenic properties, over the last years, other important functions of <em>nesfatin</em>-<em>1</em> have been discovered, many of them related to energy homeostasis, e.g. energy expenditure and glucose homeostasis. <em>Nesfatin</em>-<em>1</em> is not only affecting these physiological processes but also the alterations of the metabolic state (e.g. fat mass, glycemic state) have an impact on the synthesis and release of NUCB2 and/or <em>nesfatin</em>-<em>1</em>. Furthermore, <em>nesfatin</em>-<em>1</em> exerts pleiotropic actions at the level of cardiovascular and digestive systems, as well as plays a role in stress response, behavior, sleep and reproduction. Despite the recent advances in <em>nesfatin</em>-<em>1</em> research, a putative receptor has not been identified and furthermore potentially distinct functions of <em>nesfatin</em>-<em>1</em> and its precursor NUCB2 have not been dissected yet. To tackle these open questions will be the major objectives of future research to broaden our knowledge on NUCB2/<em>nesfatin</em>-<em>1</em>.

The metabolic peptide hormone <em>nesfatin</em>-<em>1</em> has been linked to the reproductive axis in fishes. The purpose of this study was to determine how energy availability after spawning affects plasma levels of <em>nesfatin</em>-<em>1</em>, the metabolic peptide hormone ghrelin, and sex steroid hormones in rematuring female rainbow trout (Oncorhynchus mykiss). To limit reproductive maturation, a group of female trout was food-restricted after spawning and compared with a control group that was fed a standard broodstock ration. The experiment was conducted twice, once using two-year-old trout (second-time spawners) and once using three-year-old trout (third-time spawners). During monthly sampling, blood was collected from all fish, and a subset of fish from each treatment was sacrificed for pituitaries. Pituitary follicle-stimulating hormone-beta (fsh-β) mRNA expression was analyzed with q-RT-PCR; plasma hormone levels were quantified by radioimmunoassay (<em>1</em>7β-estradiol and ghrelin) and enzyme-linked immunosorbent assay (<em>1</em><em>1</em>-keto-testosterone and <em>nesfatin</em>-<em>1</em>). Although plasma <em>nesfatin</em>-<em>1</em> levels increased significantly in the months immediately after spawning within both feeding treatments, plasma <em>nesfatin</em>-<em>1</em> did not differ significantly between the two treatments at any point. Similarly, plasma ghrelin levels did not differ significantly between the two treatments at any point. Food restriction arrested ovarian development by <em>1</em>5-20 weeks after spawning, shown by significantly lower plasma E2 levels among restricted-ration fish. Pituitary fsh-β mRNA levels were higher among control-ration fish than restricted-ration fish starting at 20 weeks, but did not differ significantly between treatment groups until 30 weeks after spawning. Within both treatment groups, plasma <em>1</em><em>1</em>-KT was elevated immediately after spawning and rapidly decreased to and persisted at low levels; starting between 20 and 25 weeks after spawning, plasma <em>1</em><em>1</em>-KT was higher among control-ration fish than restricted-ration fish. The results from these experiments do not provide support for plasma <em>nesfatin</em>-<em>1</em> as a signal for the initiation of reproductive development in rematuring female rainbow trout.

<em>Nesfatin</em>-<em>1</em> was recently identified and introduced as food intake-regulatory hormone. Soon thereafter, mounting evidence indicated a much broader role for <em>nesfatin</em>-<em>1</em> with an involvement in the regulation of food intake, gastrointestinal motility, glucose homeostasis, blood pressure and stress. Despite the growing knowledge on the physiological regulation and functions of <em>nesfatin</em>-<em>1</em>, the receptor mediating these effects remains to be characterized. Therefore, the aim of this study was to investigate the peripheral and central localization of the <em>nesfatin</em>-<em>1</em> receptor by autoradiography. Male Sprague-Dawley rats were used and peripheral as well as brain tissue was processed for (<em>1</em>25)I-<em>nesfatin</em>-<em>1</em> autoradiography. In peripheral tissues, an autoradiographic signal was observed in the gastric mucosa of corpus and antrum, in duodenum, jejunum and ileum, while no signal was detected in the colon. Preabsorption of (<em>1</em>25)I-<em>nesfatin</em>-<em>1</em> with non-labeled <em>nesfatin</em>-<em>1</em> greatly diminished the autoradiographic signal in the stomach indicating specificity (-32%, p < 0.00<em>1</em>). A displacement assay showed an effective concentration by which 50% of (<em>1</em>25)I-<em>nesfatin</em>-<em>1</em> bound to the receptor (EC50) in the gastric corpus of 80 pM. Moreover, autoradiography was observed in endocrine tissues including the pituitary, pancreas, adrenal gland, testis and visceral adipose tissue. In addition, also heart, skeletal muscle, lung, liver and kidney showed autoradiographic signals. In the brain, strong (<em>1</em>25)I-<em>nesfatin</em>-<em>1</em> autoradiography was detected in the cortex, paraventricular nucleus of the hypothalamus, area postrema, dorsal motor nucleus of the vagus nerve and cerebellum. Based on the distribution of <em>nesfatin</em>-<em>1</em> autoradiography, <em>nesfatin</em>-<em>1</em> is a pleiotropic hormone that is involved in the regulation of several homeostatic functions.