An intriguing novel pathophysiological insight into mood disorders is the notion that one's metabolic status influences mood. In rodents, cocaine- and amphetamine-regulated transcript (CART) and <em>nesfatin</em>-<em>1</em>/NUCB2 have not only been implicated in metabolism, but in the pathobiology of anxiety and depressive-like behaviour, however they have not previously been investigated in depressed subjects. Both peptides are highly expressed in centrally projecting neurons in the Edinger-Westphal nucleus (EWcp) in the midbrain. The EWcp has been implicated in stress adaptation and stress-related mood disorders like major depressive disorder in a sex-specific manner. This is intriguing, given the fact that females have higher prevalence of mood disorders. Here, we hypothesized that the expression of CART and <em>nesfatin</em>-<em>1</em> in EWcp would exhibit a sex-specific difference between depressed suicide victims vs. controls. We found that CART and <em>nesfatin</em>/NUCB2 colocalized in the human EWcp, and that CART mRNA content was much higher in both male (×3.8) and female (×5.9) drug-free suicide victims than in controls (persons who died without any diagnosed neurodegenerative or psychiatric disorder). Similarly, NUCB2 mRNA content was also higher (×<em>1</em>.8) in male suicides, whereas in female suicide victims, these contents were ×2.7 lower compared to controls. These observations are the first to show changes in the dynamics of CART and <em>nesfatin</em>/NUCB2 expressions in the midbrain of drug-free depressed suicide victims vs. controls. This article is part of a Special Issue entitled 'Anxiety and Depression'.

OBJECTIVE

Osteoarthritis (OA) is a joint degenerative biomechanical disorder involving immunity, metabolic alterations, inflammation, and cartilage degradation, where chondrocytes play a pivotal role. OA has not effective pharmacological treatments and new therapeutic targets are needed. Adipokines contribute to the low-grade systemic inflammation in OA. Here, we explored novel molecular mechanisms of sodium butyrate (BuNa) in modulating inflammation and chemotaxis in chondrocytes, demonstrating the direct involvement of its G protein-coupled receptor (GPR)-43.

METHODS

ATDC5 murine chondrocytes were stimulated with interleukin (IL)-<em>1</em>β, in the presence or not of BuNa, for 24 h. RT-PCR and Western blot analysis was performed to evaluate the expression of inflammatory mediators and structural proteins.

RESULTS

Butyrate reduced the expression of canonic pro-inflammatory mediators (Nos2, COX-2, IL-6), pro-inflammatory adipokines (lipocalin-2 and <em>nesfatin</em>-<em>1</em>) and adhesion molecule (VCAM-<em>1</em> and ICAM-<em>1</em>) in IL-<em>1</em>β-stimulated chondrocytes, inhibiting several inflammatory signalling pathways (NFκB, MAPKinase, AMPK-α, PI3K/Akt). Butyrate also reduced metalloproteinase production and limited the loss of type II collagen in IL-<em>1</em>β-inflamed chondrocytes. The chemoattractant effect of butyrate, after different inflammatory challenges, was revealed by increased annexin (AnxA)<em>1</em> levels and chemokines expression. The chemoattractant and anti-inflammatory activities of butyrate were completely blunted by GPR43 silencing using RNA interference.

CONCLUSIONS

Taken together, our data suggest the potential application of sodium butyrate as a novel candidate in a multi-target approach for the treatment of chondrocyte inflammation and cartilage degenerative process.

BACKGROUND Gestational diabetes mellitus (GDM) is common all over the world. GDM women are with inflammatory and metabolisms abnormalities. However, few studies have focused on the association of IL-65-72C/G and TNF-α -857C/T single nucleotide polymorphisms (SNPs), inflammatory biomarkers, and metabolic indexes in women with GDM, especially in the Inner Mongolia population. The aim of this study was to investigate the associations of IL-65-72C/G and TNF-α -857C/T SNPs, and inflammation and metabolic biomarkers in women with GDM pregnancies. MATERIAL AND METHODS Blood samples and placentas from <em>1</em>40 women with GDM and <em>1</em>40 women with healthy pregnancies were collected. Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) and MassARRAY-IPLEX were performed to analyze IL-65-72C/G and TNF-α -857C/T SNPs. Enzyme linked immunosorbent assay (ELISA) was performed to analyze inflammatory biomarkers and adipokines. RESULTS Distribution frequency of TNF-α -857CT (OR=3.3<em>1</em>6, 95% CI=<em>1</em>.092-8.304, p=0.025) in women with GDM pregnancies were obviously higher than that in women with healthy pregnancies. Women with GDM were of older maternal age, had higher BMI, were more nulliparous, and had T2DM and GDM history, compared to women with healthy pregnancies (p<0.05). Inflammatory biomarkers in serum (hs-CRP, IL-6, IL-8, IL-6/IL-<em>1</em>0 ratio) and placental (NF-κB, IL-6, IL-8, IL-6/IL-<em>1</em>0 ratio, IL-<em>1</em>b, TNF-α) were significantly different (p<0.05) between women with GDM and women with healthy pregnancies. Differences were found for serum FBG, FINS, HOMA-IR, and HOMA-β, and placental IRS-<em>1</em>, IRS-2, leptin, adiponectin, visfatin, RBP-4, chemerin, <em>nesfatin</em>-<em>1</em>, FATP-4, EL, LPL, FABP-<em>1</em>, FABP-3, FABP-4, and FABP-5. CONCLUSIONS TNF-α -857C/T SNP, hs-CRP, IL-6, IL-8, and IL-6/IL-<em>1</em>0 were associated with GDM in women from Inner Mongolia, as was serious inflammation and disordered lipid and glucose metabolisms.

<em>Nesfatin</em>-<em>1</em>, an anorexic nucleobindin-2 (NUCB2)-derived hypothalamic peptide, controls appetite and energy metabolism. Recent studies show that <em>nesfatin</em>-<em>1</em>/NUCB2 is expressed not only in the brain but also in gastric and adipose tissues. Thus, we investigated the distributions of <em>nesfatin</em>-<em>1</em>/NUCB2 in various tissues of male and female mice by real-time PCR, western blotting, and immunohistochemical staining. Real-time PCR analyses showed that NUCB2 mRNA was predominantly expressed in the pituitary and at lower levels in the hypothalamus, spleen, thymus, heart, liver, and muscle of both male and female mice. Expression was much higher in reproductive organs, such as the testis, epididymis, ovary, and uterus, than in the hypothalamus. Western blot analysis of the <em>nesfatin</em>-<em>1</em> protein level showed similar results to the real-time PCR analyses in both male and female mice. These results suggest that <em>nesfatin</em>-<em>1</em>/NUCB2 have widespread physiological effects in endocrine and non-endocrine organs. In addition, immunohistochemical staining revealed that <em>nesfatin</em>-<em>1</em> was localized in interstitial cells, including Leydig cells and in the columnar epithelium of the epididymis. <em>Nesfatin</em>-<em>1</em> was also expressed in theca cells and interstitial cells in the ovary and in epithelial cells of the endometrium and uterine glands in the uterus. These results suggest that <em>nesfatin</em>-<em>1</em> is a novel potent regulator of steroidogenesis and gonadal function in male and female reproductive organs. Further studies are required to elucidate the functions of <em>nesfatin</em>-<em>1</em> in various organs of male and female mice.

Obesity is the most common metabolic disease whose prevalence is increasing worldwide. This condition is considered a serious public health problem due to associated comorbidities such as diabetes mellitus and hypertension. Perinatal morbidity related to obesity does not end with birth; this continues affecting the mother/infant binomial and could negatively impact on metabolism during early infant nutrition. Nutrition in early stages of growth may be essential in the development of obesity in adulthood, supporting the concept of "nutritional programming". For this reason, breastfeeding may play an important role in this programming. Breast milk is the most recommended feeding for the newborn due to the provided benefits such as protection against obesity and diabetes. Health benefits are based on milk components such as bioactive molecules, specifically hormones involved in the regulation of food intake. Identification of these molecules has increased in recent years but its action has not been fully clarified. Hormones such as leptin, insulin, ghrelin, adiponectin, resistin, obestatin and insulin-like growth factor-<em>1</em> copeptin, apelin, and <em>nesfatin</em>, among others, have been identified in the milk of normal-weight women and may influence the energy balance because they can activate orexigenic or anorexigenic pathways depending on energy requirements and body stores. It is important to emphasize that, although the number of biomolecules identified in milk involved in regulating food intake has increased considerably, there is a lack of studies aimed at elucidating the effect these hormones may have on metabolism and development of the newborn. Therefore, we present a state-of-the-art review regarding bioactive compounds such as hormones secreted in breast milk and their possible impact on nutritional programming in the infant, analyzing their functions in appetite regulation.

Earlier examination reported that central injection of <em>nesfatin</em>-<em>1</em> elevated blood pressure and suppressed food intake in conscious rats. In this study, we analyzed the effects of the intracerebroventricular injection of <em>nesfatin</em>-<em>1</em> on the sympathetic nerve outflow to the kidney in urethane-anesthetized rats. An intracerebroventricular injection of <em>nesfatin</em>-<em>1</em> significantly stimulated renal sympathetic nerve activity and blood pressure in a dose-dependent manner. Moreover, we examined the role of the melanocortin system on the sympathoexcitation caused by the <em>nesfatin</em>-<em>1</em> injection. Pretreatment with the melanocortin-3/4 receptor antagonist, SHU9<em>1</em><em>1</em>9, abolished the increase in nerve activity and blood pressure induced by <em>nesfatin</em>-<em>1</em>. Thus, the stimulating effects of <em>nesfatin</em>-<em>1</em> administration on the sympathetic nerve activity of the kidney may depend on the central melanocortin system.

<em>Nesfatin</em>-<em>1</em>, a peptide whose receptor is yet to be identified, has been involved in the modulation of feeding, stress, and metabolic responses. More recently, increasing evidence supports a modulatory role for <em>nesfatin</em>-<em>1</em> in autonomic and cardiovascular activity. This study was undertaken to test if the expression of <em>nesfatin</em>-<em>1</em> in the nucleus ambiguus, a key site for parasympathetic cardiac control, may be correlated with a functional role. As we have previously demonstrated that <em>nesfatin</em>-<em>1</em> elicits Ca²⁺ signaling in hypothalamic neurons, we first assessed the effect of this peptide on cytosolic Ca²⁺ in cardiac pre-ganglionic neurons of nucleus ambiguus. We provide evidence that <em>nesfatin</em>-<em>1</em> increases cytosolic Ca²⁺ concentration via a Gi/o-coupled mechanism. The <em>nesfatin</em>-<em>1</em>-induced Ca²⁺ rise is critically dependent on Ca²⁺ influx via P/Q-type voltage-activated Ca²⁺ channels. Repeated administration of <em>nesfatin</em>-<em>1</em> leads to tachyphylaxis. Furthermore, <em>nesfatin</em>-<em>1</em> produces a dose-dependent depolarization of cardiac vagal neurons via a Gi/o-coupled mechanism. In vivo studies, using telemetric and tail-cuff monitoring of heart rate and blood pressure, indicate that microinjection of <em>nesfatin</em>-<em>1</em> into the nucleus ambiguus produces bradycardia not accompanied by a change in blood pressure in conscious rats. Taken together, our results identify for the first time that <em>nesfatin</em>-<em>1</em> decreases heart rate by activating cardiac vagal neurons of nucleus ambiguus. Our results indicate that <em>nesfatin</em>-<em>1</em>, one of the most potent feeding peptides, increases cytosolic Ca²⁺ by promoting Ca²⁺ influx via P/Q channels and depolarizes nucleus ambiguus neurons; both effects are Gi/o-mediated. In vivo studies indicate that microinjection of <em>nesfatin</em>-<em>1</em> into nucleus ambiguus produces bradycardia in conscious rats. This is the first report that <em>nesfatin</em>-<em>1</em> increases the parasympathetic cardiac tone.

OBJECTIVE

Thyroid dysfunction is frequently observed in patients with type 2 diabetes mellitus (T2DM), but the underlying mechanism is still poorly understood. The present study aimed to investigate whether <em>nesfatin</em>-<em>1</em> played a role in the thyroid dysfunction in patients with T2DM.

METHODS

55 euthyroid patients were enrolled in this study including 30 patients with T2DM and 25 patients with impaired glucose regulation (IGR). 30 age-matched healthy people were also included as the control. The plasma levels of <em>nesfatin</em>-<em>1</em>, thyrotropin (TSH), and glycosylated hemoglobin (HbA<em>1</em>c) as well as the body mass index (BMI) were comparatively analyzed among the three groups.

RESULTS

The <em>nesfatin</em>-<em>1</em> was significantly lower in patients with T2DM than in patients with IGR and in the control. On the contrary, the TSH level was significantly higher in patients with T2DM than in patients with IGR and in the control. Simple regression analysis showed that the plasma <em>nesfatin</em>-<em>1</em> was negatively correlated with the TSH and HbA<em>1</em>c levels and positively correlated with the BMI. With multiple stepwise regression analysis, the <em>nesfatin</em>-<em>1</em> remained to be independently correlated with the TSH, BMI, and HbA<em>1</em>c.

CONCLUSIONS

The study was suggesting a role of <em>nesfatin</em>-<em>1</em> in thyroid dysfunction in patients with T2DM.

<em>Nesfatin</em>-<em>1</em> is the N-terminal fragment of nucleobindin-2 (NUCB2). The antibody against <em>nesfatin</em>-<em>1</em> recognizes both full length of NUCB2 and <em>nesfatin</em>-<em>1</em>, thus the immunolabeling represents NUCB2/<em>nesfatin</em>-<em>1</em>. It has been found that NUCB2/<em>nesfatin</em>-<em>1</em> is widely distributed in the rodent central nervous system. The immunoreactivity is more intensive in the brain autonomic centers that regulate feeding, neuroendocrine and cardiovascular functions, such as the hypothalamic paraventricular nucleus, supraoptic nucleus, lateral hypothalamic area, Edinger-Westphal nucleus, locus coeruleus, dorsal vagal complex and medullary raphe nuclei. In neurons, NUCB2/<em>nesfatin</em>-<em>1</em> is located in the soma and primary dendrites, not in nerve fibers. NUCB2/<em>nesfatin</em>-<em>1</em> is co-localized with several neurotransmitters involved in regulation of food intake, autonomic and neuroendocrine functions, including oxytocin, vasopressin, neuropeptide Y, cocaine- and amphetamine-regulated transcript, proopiomelanocortin, α-melanocyte-stimulating hormone, melanin-concentrating hormone, leptin, mammalian target of rapamycin, urocortin-<em>1</em>, corticotropin-releasing factor and serotonin. In the periphery, NUCB2/<em>nesfatin</em>-<em>1</em> is located mainly in the pituitary, gastric mucosa where it coexists with ghrelin, and pancreatic endocrine cells containing insulin. <em>Nesfatin</em>-<em>1</em> is detectable in the cerebrospinal fluid of rats. NUCB2/<em>nesfatin</em>-<em>1</em> is measurable in the plasma, and altered under different conditions in rodents and humans, such as immune challenge, high fat diet and exercise, anorexia nervosa, anxiety and depression. Anatomical data suggest that <em>nesfatin</em>-<em>1</em> is a unique neuroendocrine peptide that may be involved in regulation of homeostasis.

<em>Nesfatin</em>-<em>1</em> is an anorexigenic peptide originating from nucleobinding-2 (NUCB2) protein. <em>Nesfatin</em>-<em>1</em>/NUCB2-immunoreactive neurons are present in the hypothalamic paraventricular nucleus, the center of the stress-axis, and in the medullary A<em>1</em> and A2 catecholamine cell groups. The A<em>1</em> and A2 cell groups mediate viscerosensory stress information toward the hypothalamic paraventricular nucleus. They contain noradrenaline, but subsets of these neurons also express prolactin-releasing peptide acting synergistically with noradrenaline in the activation of the hypothalamic paraventricular nucleus during stress. We investigated the possible role of <em>nesfatin</em>-<em>1</em>/NUCB2 in the stress response. Intracerebro-ventricular administration of <em>nesfatin</em>-<em>1</em> elevated both plasma adrenocorticotropin and corticosterone levels, while in vitro stimulation of the hypophysis was ineffective. Single, long-duration restraint stress activated (Fos positivity) many of the <em>nesfatin</em>-<em>1</em>/NUCB2-immunoreactive neurons in the parvocellular part of the hypothalamic paraventricular nucleus, evoked <em>nesfatin</em>-<em>1</em>/NUCB2 mRNA expression in the parvocellular part of the paraventricular nucleus and in the A<em>1</em>, but not in the A2 cell group. <em>Nesfatin</em>-<em>1</em>/NUCB2 was shown to co-localize in a high percentage of prolactin-releasing peptide producing neurons, in both medullary catecholamine cell groups further supporting its involvement in the stress response. Finally, bilateral adrenalectomy evoked an increasing <em>nesfatin</em>-<em>1</em>/NUCB2 mRNA expression, indicating that it is under the negative feedback of adrenal steroids. These data provide the first evidence for possible participation of <em>nesfatin</em>-<em>1</em>/NUCB2 in the stress-axis regulation, both at the level of the brainstem and in the hypothalamus.

Besides its role as an energy storage organ, adipose tissue can be viewed as a dynamic and complex endocrine organ, which produces and secretes several adipokines, including hormones, cytokines, extracellular matrix (ECM) proteins, and growth and vasoactive factors. A wide body of evidence showed that adipokines play a critical role in various biological and physiological functions, among which feeding modulation, inflammatory and immune function, glucose and lipid metabolism, and blood pressure control. The aim of this review is to summarize the effects of several adipokines, including leptin, diponectin, resistin, chemerin, lipocalin-2 (LCN2), vaspin, omentin, follistatin-like <em>1</em> (FSTL<em>1</em>), secreted protein acidic and rich in cysteine (SPARC), secreted frizzled-related protein 5 (SFRP5), C<em>1</em>q/TNF-related proteins (CTRPs), family with sequence similarity to <em>1</em>9 member A5 (FAM<em>1</em>9A5), wingless-type inducible signaling pathway protein-<em>1</em> (WISP<em>1</em>), progranulin (PGRN), <em>nesfatin</em>-<em>1</em> (<em>nesfatin</em>), visfatin/PBEF/NAMPT, apelin, retinol binding protein 4 (RPB4), and plasminogen activator inhibitor-<em>1</em> (PAI-<em>1</em>) in the regulation of insulin resistance and vascular function, as well as many aspects of inflammation and immunity and their potential role in managing obesity-associated diseases, including metabolic, osteoarticular, and cardiovascular diseases.

Keywords: adipokines; cardiovascular disorders; obesity; rheumatoid arthritis; therapeutic targets; type 2 diabetes mellitus.

<em>Nesfatin</em>-<em>1</em> is cleaved from nucleobindin2 (NUCB2) and implicated in the regulation of hunger and satiety as anorexigenic peptide hormone. Circulating NUCB2/<em>nesfatin</em>-<em>1</em> is elevated in obesity and decreased in anorexia nervosa. In addition, a role in the regulation of stress, anxiety and depression has been demonstrated. First evidence suggested that NUCB2/<em>nesfatin</em>-<em>1</em> might be regulated in a sex-specific manner. Thus, we investigated NUCB2/<em>nesfatin</em>-<em>1</em> plasma levels in association with perceived stress, anxiety and depressiveness in obese men and women. We enrolled <em>1</em>40 inpatients (87 female, 53 male; body mass index, BMI, 30.3-8<em>1</em>.7 kg/m(2)) hospitalized due to obesity with mental and somatic comorbidities. Perceived stress (PSQ-20), anxiety (GAD-7), and depressiveness (PHQ-9) were measured psychometrically, and at the same time NUCB2/<em>nesfatin</em>-<em>1</em> plasma levels by ELISA. Males and females did not differ in terms of age and BMI. NUCB2/<em>nesfatin</em>-<em>1</em> did not show a correlation with age or BMI. Mean NUCB2/<em>nesfatin</em>-<em>1</em> levels (+25%, p<0.00<em>1</em>) as well as mean scores for perceived stress (+26%, p < 0.0<em>1</em>), anxiety (+54%, p < 0.00<em>1</em>) and depressiveness (+32%, p = 0.02) were higher in females compared to males. Scores for perceived stress (r = 0.39; p < 0.00<em>1</em>) and depressiveness (r = 0.35; p < 0.0<em>1</em>) showed a positive correlation with NUCB2/<em>nesfatin</em>-<em>1</em> in women, while in men no correlation was observed (p>0.<em>1</em>9). The strongest association was observed between NUCB2/<em>nesfatin</em>-<em>1</em> and anxiety with a positive correlation in women (r = 0.54; p < 0.00<em>1</em>), while in men even an inverse correlation was found (r = -0.32; p = 0.03). This result was reflected in higher NUCB2/<em>nesfatin</em>-<em>1</em> levels in women with high versus low anxiety (+5<em>1</em>%, p<0.00<em>1</em>) and an opposite alteration in men (-<em>1</em>7%, p = 0.04) after a median split into two groups with high and low anxiety. In conclusion, circulating NUCB2/<em>nesfatin</em>-<em>1</em> showed a positive correlation with anxiety, perceived stress, and depressiveness in obese women. In men, no correlation with perceived stress and depressiveness was observed, whereas the association with anxiety was inverse, pointing towards a sex-specific regulation. These results corroborate the suggestion of NUCB2/<em>nesfatin</em>-<em>1</em> being relevantly involved in the regulation of mood and stress in a sex-specific way.

COPD (chronic obstructive pulmonary disease) is a common lung disease characterized by airflow limitation and systemic inflammation. Recently, adipose tissue mediated inflammation has gathered increasing interest in the pathogenesis of the disease. In this study, we investigated the role of novel adipocytokines <em>nesfatin</em>-<em>1</em> and visfatin in COPD by measuring if they are associated with the inflammatory activity, lung function, or symptoms. Plasma levels of NUCB2/<em>nesfatin</em>-<em>1</em> and visfatin were measured together with IL-6, IL-8, TNF- α , and MMP-9, lung function, exhaled nitric oxide, and symptoms in 43 male patients with emphysematous COPD. The measurements were repeated in a subgroup of the patients after four weeks' treatment with inhaled fluticasone. Both visfatin and NUCB2/<em>nesfatin</em>-<em>1</em> correlated positively with plasma levels of IL-6 (r = 0.34<em>1</em>, P = 0.027 and rho = 0.40<em>1</em>, P = 0.008, resp.) and TNF- α (r = 0.305, P = 0.052 and rho = 0.329, P = 0.033, resp.) and NUCB2/<em>nesfatin</em>-<em>1</em> also with IL-8 (rho = 0.32<em>1</em>, P = 0.036) in patients with COPD. Further, the plasma levels of visfatin correlated negatively with pulmonary diffusing capacity (r = -0.369, P = 0.0<em>1</em>6). Neither of the adipokines was affected by fluticasone treatment and they were not related to steroid-responsiveness. The present results introduce adipocytokines NUCB2/<em>nesfatin</em>-<em>1</em> and visfatin as novel factors associated with systemic inflammation in COPD and suggest that visfatin may mediate impaired pulmonary diffusing capacity.

Nucleobindin-2 derived <em>nesfatin</em>-<em>1</em> in the hypothalamic paraventricular nucleus (PVN) plays a role in inhibition of feeding. The neural pathways downstream of PVN <em>nesfatin</em>-<em>1</em> have been extensively investigated. However, regulation of the PVN <em>nesfatin</em>-<em>1</em> neurons remains unclear. Since starvation decreases and refeeding stimulates <em>nesfatin</em>-<em>1</em> expression specifically in the PVN, this study aimed to clarify direct effects of meal-evoked metabolic factors, glucose and insulin, on PVN <em>nesfatin</em>-<em>1</em> neurons. High glucose (<em>1</em>0mM) and insulin (<em>1</em>0(-<em>1</em>3)M) increased cytosolic calcium concentration ([Ca(2+)](i)) in 55 of 33<em>1</em> (<em>1</em>6.6%) and 32 of 249 (<em>1</em>2.9%) PVN neurons, respectively. Post [Ca(2+)](i) measurement immunocytochemistry identified that 58.2% of glucose-responsive and 62.5% of insulin-responsive neurons were immunoreactive to <em>nesfatin</em>-<em>1</em>. Furthermore, a fraction of the glucose-responsive <em>nesfatin</em>-<em>1</em> neurons also responded to insulin, and vice versa. Some of the neurons that responded to neither glucose nor insulin were recruited to [Ca(2+)](i) increases by glucose and insulin in combination. Our data demonstrate that glucose and insulin directly interact with and increase [Ca(2+)](i) in <em>nesfatin</em>-<em>1</em> neurons in the PVN, and that the <em>nesfatin</em>-<em>1</em> neuron is the primary target for them in the PVN. The results suggest that high glucose- and insulin-induced activation of PVN <em>nesfatin</em>-<em>1</em> neurons serves as a mechanism through which meal ingestion stimulates <em>nesfatin</em>-<em>1</em> neurons in the PVN and thereby produces satiety.

Previous studies have demonstrated that mammalian target of rapamycin (mTOR) signalling in the hypothalamus is involved in the control of energy homeostasis. The aim of this study was to characterize the effect of mTOR signalling in the dorsal motor nucleus of the vagus (DMNV) on energy intake. Phospho-mTOR was detected in the DMNV neurons, and its levels were increased by energy deprivation. Rapamycin significantly inhibited mTOR activity and reduced food intake when administrated into the fourth ventricle. Exposure of DMNV neurons to ghrelin increased the phosphorylation of mTOR. Injection of ghrelin into the fourth ventricle significantly increased food intake relative to the control vehicle. Pretreatment with rapamycin for <em>1</em>5 min attenuated the orexigenic effect of ghrelin. A reduction in the phosphorylation of mTOR was observed following injection of <em>nesfatin</em>-<em>1</em> into the fourth ventricle. When administrated by injection into the fourth ventricle, <em>nesfatin</em>-<em>1</em> suppressed food intake in comparison with the control vehicle. The anorexigenic effect of <em>nesfatin</em>-<em>1</em> was significantly attenuated by pretreatment with leucine for <em>1</em>5 min. All these findings suggest that mTOR signalling in the DMNV neurons regulates both the nutrient and the hormonal signals for the modulation of food intake.

Ingestion of food affects secretion of hormones from enteroendocrine cells located in the gastrointestinal mucosa. These hormones are involved in the regulation of various gastrointestinal functions including the control of food intake. One cell in the stomach, the X/A-like has received much attention over the past years due to the production of ghrelin. Until now, ghrelin is the only known orexigenic hormone that is peripherally produced and centrally acting to stimulate food intake. Subsequently, additional peptide products of this cell have been described including desacyl ghrelin, obestatin and <em>nesfatin</em>-<em>1</em>. Desacyl ghrelin seems to be involved in the regulation of food intake as well and could play a counter-balancing role of ghrelin's orexigenic effect. In contrast, the initially proposed anorexigenic action of obestatin did not hold true and therefore the involvement of this peptide in the regulation of feeding is questionable. Lastly, the identification of <em>nesfatin</em>-<em>1</em> in the same cell in different vesicles than ghrelin extended the function of this cell type to the inhibition of feeding. Therefore, this X/A-like cell could play a unique role by encompassing yin and yang properties to mediate not only hunger but also satiety.

The nucleobindins, nucleobindin <em>1</em> (NUCB<em>1</em>) and nucleobindin 2 (NUCB2), are homologous multidomain calcium and DNA binding proteins. NUCB<em>1</em> is a well-characterized Golgi protein found within the rat pituitary, liver and kidney with functions related to immunity, calcium homeostasis and G protein signaling. NUCB2 is found both in the hypothalamus and brain stem centers, as well as peripherally in the digestive tract. Renewed interest in the nucleobindins has been sparked by the recent discovery of <em>nesfatin</em>-<em>1</em>, an endocrine factor post-translationally processed from the N-terminal of NUCB2. <em>Nesfatin</em>-<em>1</em> has quickly established itself as a novel regulator of appetite, insulin secretion, energy homeostasis and reproduction with important consequences to the etiology of metabolic diseases including diabetes and obesity. The discovery of <em>nesfatin</em>-<em>1</em> and it endocrine functions attracted more attention to the nucleobindins that are already known to have important intracellular functions. From the sequence information available, it is possible that nucelobindins itself or <em>nesfatin</em>-<em>1</em> like peptides within the NUCB<em>1</em> could also elicit <em>nesfatin</em>-<em>1</em>-like biological functions. The research on <em>nesfatin</em>-<em>1</em> in last 5years further adds to the importance of nucleobindins as potential endocrine precursors. This review aims to summarize some of the most recent findings on the functional significance of NUCB<em>1</em>, NUCB2, as well as encoded proteins and highlights the questions that remain unanswered.

The recently discovered <em>nesfatin</em>-<em>1</em> is regulated by hunger and satiety. The precursor protein NUCB2 is proteolytically cleaved into three resulting fragments: <em>nesfatin</em>-<em>1</em>, <em>nesfatin</em>-2, and <em>nesfatin</em>-3. The middle segment of <em>nesfatin</em>-<em>1</em> (M30) is responsible for limiting food intake, while the exact physiological role of <em>nesfatin</em>-2 and <em>nesfatin</em>-3 are not currently known yet. This hormone plays role/roles on diabetic hyperphagia, epilepsy, mood, stress, sleeping, anxiety, hyperpolarization, depolarization, and reproductive functions. This review will address <em>nesfatin</em>, focusing on its discovery and designation, biochemical structure, scientific evidence of its anorexigenic character, the results of the human and animal studies until the present day, its main biochemical and physiological effects, and its possible clinical applications.

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver pathology worldwide and is strongly associated with obesity and insulin-resistance and food intake. <em>Nesfatin</em>-<em>1</em> is a new peptide that controls appetite and food intake. The objective of this research was to examine the serum concentrations of <em>nesfatin</em>-<em>1</em> in NAFLD.

METHODS

Thirty NAFLD patients who had elevated liver enzymes and 40 age- and sex-matched healthy subjects were included in this study. NAFLD was diagnosed and graded with the findings of liver ultrasound scan. <em>Nesfatin</em>-<em>1</em> concentrations were measured using an ELISA method and the relationship between <em>nesfatin</em>-<em>1</em> and metabolic parameters were investigated. The subjects were divided into two groups according to their body mass index (≥ 30 and < 30) and <em>nesfatin</em>-<em>1</em> concentrations were examined between both groups.

RESULTS

Serum <em>nesfatin</em>-<em>1</em> concentrations in NAFLD patients were lower than healthy controls (0.26 ± 0.<em>1</em>4 ng/ml, 0.38 ± 0.<em>1</em>8 ng/ml, respectively, and p = 0.008). We found a negative correlation between <em>nesfatin</em>-<em>1</em> and fasting glucose and body mass index. In obese subjects, serum <em>nesfatin</em>-<em>1</em> concentrations were significantly lower when compared with non-obese subjects (0.26 ± 0.<em>1</em>2 ng/ml, 0.37 ± 0.<em>1</em>9 ng/ml, respectively; p = 0.0<em>1</em>4). In addition, we showed that <em>nesfatin</em>-<em>1</em> concentrations in subjects with insulin resistance were significantly lower in comparison with insulin-sensitive ones (0.27 ± 0.<em>1</em>7 ng/ml, 0.38 ± 0.<em>1</em>7 ng/ml, respectively; p = 0.0<em>1</em>5).

CONCLUSIONS

Our study has shown that <em>nesfatin</em>-<em>1</em> concentrations were reduced in NAFLD. The results of this study indicate that <em>nesfatin</em>-<em>1</em> may have a significant role in NAFLD.

<em>Nesfatin</em>-<em>1</em>, an 82-amino acid neuropeptide, has recently been characterized as a potent metabolic regulator. However, the metabolic mechanisms and signaling steps directly associated with the action of <em>nesfatin</em>-<em>1</em> have not been well delineated. We established a loss-of-function model of hypothalamic <em>nesfatin</em>-<em>1</em>/NUCB2 signaling in rats through an adenoviral-mediated RNA interference. With this model, we found that inhibition of central <em>nesfatin</em>-<em>1</em>/NUCB2 activity markedly increased food intake and hepatic glucose flux and decreased glucose uptake in peripheral tissue in rats fed either a normal chow diet (NCD) or a high-fat diet (HFD). The change of hepatic glucose fluxes in the hypothalamic <em>nesfatin</em>-<em>1</em>/NUCB2 knockdown rats was accompanied by increased hepatic levels of glucose-6-phosphatase and PEPCK and decreased insulin receptor, insulin receptor substrate <em>1</em>, and AKT kinase phosphorylation. Furthermore, knockdown of hypothalamic <em>nesfatin</em>-<em>1</em> led to decreased phosphorylation of mammalian target of rapamycin (mTOR) and signal transducer and activator of transcription 3 (STAT3) and the subsequent suppressor of cytokine signaling 3 levels. These results demonstrate that hypothalamic <em>nesfatin</em>-<em>1</em>/NUCB2 plays an important role in glucose homeostasis and hepatic insulin sensitivity, which is, at least in part, associated with the activation of the mTOR-STAT3 signaling pathway.

<em>Nesfatin</em>-<em>1</em> is a recently identified anorexigenic peptide that has been implicated in appetite regulation, weight loss and/or malnutrition. Anorexia and malnutrition are common features of chronic kidney disease (CKD) that predispose patients to worse outcomes. However, the reasons for the occurrence of anorexia in CKD patients are not fully elucidated. The aim of this study was to investigate the association between <em>nesfatin</em>-<em>1</em> and protein intake and body composition in patients undergoing hemodialysis (HD). Twenty five HD patients from a private Clinic in Rio de Janeiro, Brazil were studied and compared with <em>1</em>5 healthy subjects that were matched for body mass index (BMI), % body fat mass (by anthropometrics) and age. Appetite was measured using a specific questionnaire, and food intake was evaluated based on 3-day food records. <em>Nesfatin</em>-<em>1</em> levels were measured by ELISA and leptin, TNF-α and IL-6 levels were determined by a multiplex assay kit. Serum <em>nesfatin</em>-<em>1</em> levels did not differ between HD patients (0.<em>1</em>6±0.07ng/mL) and healthy subjects (0.<em>1</em>7±0.<em>1</em>0ng/mL). <em>Nesfatin</em>-<em>1</em> levels showed significant negative correlations with protein intake (r=-0.42; p=0.03), but did not associate with inflammatory markers or appetite scores. Combining patients and controls, we observed positive correlations with BMI (r=0.33; p=0.03), % body fat (r=0.35; p=0.03), leptin (r=0.45; p=0.006) and the triceps skinfold thickness (r=0.36; p=0.02). In multivariate analysis % body fat was the main determinant of <em>nesfatin</em>-<em>1</em> variance. In conclusion, <em>nesfatin</em>-<em>1</em> levels did not differ between HD patients and healthy subjects and negatively correlated with protein intake. This pathway is likely not dysregulated in uremia.

Obesity is one of the most important health problems today. Obesity is mostly caused by a complex interaction between environmental and genetic factors. However, several monogenic forms of obesity also exist. The mutations causing these forms of obesity were all found in genes involved in the leptin-melanocortin pathway: leptin, leptin receptor, proopiomelanocortin, prohormone convertase <em>1</em>, and melanocortin-4 receptor. Recently, several novel players with a role in this pathway have been identified and have increased our knowledge on the regulation of food intake. These include the melanocortin-3 receptor, BDNF, SIM<em>1</em>, and <em>nesfatin</em>-<em>1</em>. In this review, we will discuss the most important players involved in this pathway. We will focus on genetic studies concerning mouse models involving these genes and reported human variation in these genes. We intend to provide an extensive overview of all currently known proteins with a significant role in this pathway. Together, these data demonstrate the importance of this pathway in the regulation of food intake and the pathogenesis of obesity.

<em>Nesfatin</em>-<em>1</em> is an eighty two amino acid, naturally occurring multifunctional protein encoded in the precursor nucleobindin-2 (NUCB2). A comparison of sequences indicates that NUCB2 is present in a number of animals, from hydra to humans. The 30 amino acid mid-segment of <em>nesfatin</em>-<em>1</em> is considered to be the bioactive core of the protein, and this region displays the highest identity among <em>nesfatin</em>-<em>1</em> sequences reported thus far. Similar to the sequence relationships observed, the tissue-specific expression and biological actions of <em>nesfatin</em>-<em>1</em> also appear to be highly conserved across species. For example, brain is a major tissue abundantly expressing <em>nesfatin</em>- <em>1</em> in several species. It has been shown that various key regions of the rat, mouse and goldfish brain, which are involved in the regulation of feeding and metabolism express <em>nesfatin</em>-<em>1</em>. Exogenous administration of <em>nesfatin</em>-<em>1</em> results in a decrease in the food intake of rats, mice and goldfish. In addition, <em>nesfatin</em>-<em>1</em> has been shown to regulate a number of other physiological processes including hormone secretion from the pancreatic islets and pituitary gland, stress and behavior. While <em>nesfatin</em>-<em>1</em> research still remains an emerging area in physiology, the literature available thus far clearly shows that <em>nesfatin</em>-<em>1</em> is an important regulator of homeostasis in animals.

This review focuses on the control of appetite by food intake-regulatory peptides secreted from the gastrointestinal tract, namely cholecystokinin, glucagon-like peptide <em>1</em>, peptide YY, ghrelin, and the recently discovered <em>nesfatin</em>-<em>1</em> via the gut-brain axis. Additionally, we describe the impact of external factors such as intake of different nutrients or stress on the secretion of gastrointestinal peptides. Finally, we highlight possible conservative-physical activity and pharmacotherapy-treatment strategies for obesity as well as surgical techniques such as deep brain stimulation and bariatric surgery also altering these peptidergic pathways.