Peripheral and central localization of the nesfatin-1 receptor using autoradiography in rats

Nesfatin-1: A Novel Diagnostic and Prognostic Biomarker in Digestive Diseases

Nesfatin-1, deriving from a precursor protein, NUCB2, is a newly discovered molecule with anti-apoptotic, anti-inflammatory, antioxidant, and anorexigenic effects. It was initially identified in the central nervous system (CNS) and received increasing interest due to its energy-regulating properties. However, research showed that nesfatin-1 is also expressed in peripheral tissues, including the digestive system. The aim of this review is to give a résumé of the present state of knowledge regarding its structure, immunolocalization, and potential implications in diseases with inflammatory components. The main objective was to focus on its clinical importance as a diagnostic biomarker and potential therapeutic molecule in a variety of disorders, among which digestive disorders were of particular interest. Previous studies have shown that nesfatin-1 regulates the balance between pro- and antioxidant agents, which makes nesfatin-1 a promising therapeutic agent. Further in-depth research regarding the underlying mechanisms of action is needed for a better understanding of its effects.

Renoprotective effect of Nesfatin-1 in Adenine-Induced Chronic kidney Disease: An in vitro and in vivo study

Chronic Kidney Disease (CKD) presents a significant global health challenge with limited treatment options. Nesfatin-1, an anorexigenic peptide, has demonstrated antioxidant, anti-inflammatory, and anti-apoptotic properties in various diseases. However, the role of nesfatin-1 in CKD remains unclear. This study investigates the potential renoprotective effects of nesfatin-1 in adenine-induced CKD mice and in NRK-52E renal epithelial cells. Male C57BL/6J mice and NRK-52E renal epithelial cells were administered adenine to induce CKD. Various aspects of renal function, histopathology, oxidative stress, inflammation, apoptosis, and renal interstitial fibrosis were assessed and downstream pathways were investigated. Adenine-fed mice exhibited reduced nesfatin-1 expression and increased markers of kidney damage, including elevated blood urea nitrogen (BUN), serum creatinine, and histological abnormalities, reactive oxygen species (ROS), inflammation, apoptosis, and fibrosis. Treatment with nesfatin-1 in adenine induced mice significantly reversed these changes. Nesfatin-1 also lowered calcium levels and the expression of inflammatory markers, including IL-1β, IL-6, TNF-α, and Nf-kB. Furthermore, nesfatin-1 reduced the expression of apoptotic markers (Caspase-3, Caspase-1, Bax/Bcl2 ratio) and restored the balance of Bcl2 and MMP. Lastly, nesfatin-1 attenuated fibrotic markers (Tgf-β, Smad2/3,4, type IV collagen, α-SMA) in both adenine-induced CKD mice and NRK-52E cells. In conclusion, our results suggest that nesfatin-1 may enhance kidney function in adenine-induced CKD mice and NRK-52E cells. The renoprotective effects of nesfatin-1 are likely associated with its antioxidant, anti-inflammatory, anti-apoptotic, and anti-fibrotic properties.

Appetite- and Weight-Regulating Neuroendocrine Circuitry in Hypothalamic Obesity

Since hypothalamic obesity (HyOb) was first described over 120 years ago by Joseph Babinski and Alfred Fröhlich, advances in molecular genetic laboratory techniques have allowed us to elucidate various components of the intricate neurocircuitry governing appetite and weight regulation connecting the hypothalamus, pituitary gland, brainstem, adipose tissue, pancreas, and gastrointestinal tract. On a background of an increasing prevalence of population-level common obesity, the number of survivors of congenital (eg, septo-optic dysplasia, Prader-Willi syndrome) and acquired (eg, central nervous system tumors) hypothalamic disorders is increasing, thanks to earlier diagnosis and management as well as better oncological therapies. Although to date the discovery of several appetite-regulating peptides has led to the development of a range of targeted molecular therapies for monogenic obesity syndromes, outside of these disorders these discoveries have not translated into the development of efficacious treatments for other forms of HyOb. This review aims to summarize our current understanding of the neuroendocrine physiology of appetite and weight regulation, and explore our current understanding of the pathophysiology of HyOb.

Suppressive action of nesfatin-1 and nesfatin-1-like peptide on cortisol synthesis in human adrenal cortex cells

Nucleobindin-derived peptides, nesfatin-1 [NESF-1] and nesfatin-1-like-peptide [NLP] have diverse roles in endocrine and metabolic regulation. While both peptides showed a stimulatory effect on the synthesis of proopiomelanocortin (POMC), the adrenocorticotropic hormone (ACTH) precursor in mouse corticotrophs, whether NESF-1 and NLP have any direct effect on glucocorticoid [GC] synthesis in the adrenal cortex remains unknown. The main aim of this study was to determine if NESF-1 and/or NLP act directly on adrenal cortex cells to regulate cortisol synthesis in vitro. Whether NLP injection affects stress-hormone gene expression in the adrenal gland and pituitary in vivo in mice was also assessed. In addition, cortisol synthetic pathway in Nucb1 knockout mice was studied. Human adrenal cortical [H295R] cells showed immunoreactivity for both NUCB1/NLP and NUCB2/NESF-1. NLP and NESF-1 decreased the abundance of steroidogenic enzyme mRNAs, and cortisol synthesis and release through the AC/PKA/CREB pathway in H295R cells. Similarly, intraperitoneal injection of NLP in mice decreased the expression of enzymes involved in glucocorticoid (GC) synthesis in the adrenal gland while increasing the expression of Pomc, Pcsk1 and Crhr1 in the pituitary. Moreover, the melanocortin 2 receptor (Mc2r) mRNA level was enhanced in the adrenal gland samples of NLP injected mice. However, the global genetic disruption in Nucb1 did not affect most steroidogenic enzyme mRNAs, and Pomc, Pcsk2 and Crhr1 mRNAs in mice adrenal gland and pituitary gland, respectively. Collectively, these data provide the first evidence for a direct inhibition of cortisol synthesis and secretion by NLP and NESF-1. NUCB peptides might still elicit a net stimulatory effect on GC synthesis and secretion through their positive effects on ACTH-MC2R pathway in the pituitary.

Selenium protects against nesfatin-1 modulation of the hypothalamic-pituitary-testicular axis during hypothyroidism in male rats

Normal gonadal function can be disrupted by hypothyroidism. Hypothyroidism disturbs testicular function directly and centrally by affecting the hypothalamic-pituitary-testicular axis with unclear mechanism. As nesfatin-1 neurons co-localized with TRH and GnRH neurons in the hypothalamus, it could play a role in centrally hypothyroidism induced testicular dysfunction. Selenium (Se), by affecting thyroid iodide supply, could relieve these disturbances. So, we aim to identify the role of nesfatin-1 as a link between testicular dysfunction and hypothyroidism through modulating the MAPK/ERK pathway while discussing the possible role of Se in alleviating hypothyroidism and associated testicular damage. Forty male rats were divided equally into: Control: distilled water, Se: Se orally, Propylthiouracil (PTU): PTU orally, PTU + Se: Se with PTU orally. Serum thyroid function, gonadal hormones, nesfatin-1, testicular redox status, sperm analysis, brain tissue GnRH, nucleobindin 2-derived polypeptide, pMAPK/ERK gene expression, histological changes and immunohistochemical expression of testicular proliferating cell antigen (PCNA) were done. PTU induced hypothyroidism and reduction of gonadal hormones which both were correlated with reduced nesfatin-1. There was testicular stress with reduced GnRH, NUCB2, pMAPK/ERK gene expression, and PCNA immunopositive cells. These parameters were reversed by Se. Nesfatin-1 could be the central link between hypothyroidism and disturbances of the hypothalamic pituitary testicular axis.

The Role of Adipokines and Myokines in the Pathogenesis of Different Obesity Phenotypes-New Perspectives

Obesity is a characteristic disease of the twenty-first century that is affecting an increasing percentage of society. Obesity expresses itself in different phenotypes: normal-weight obesity (NWO), metabolically obese normal-weight (MONW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUO). A range of pathophysiological mechanisms underlie the occurrence of obesity, including inflammation, oxidative stress, adipokine secretion, and other processes related to the pathophysiology of adipose tissue (AT). Body mass index (BMI) is the key indicator in the diagnosis of obesity; however, in the case of the NWO and MONW phenotypes, the metabolic disturbances are present despite BMI being within the normal range. On the other hand, MHO subjects with elevated BMI values do not present metabolic abnormalities. The MUO phenotype involves both a high BMI value and an abnormal metabolic profile. In this regard, attention has been focused on the variety of molecules produced by AT and their role in the development of obesity. Nesfatin-1, neuregulin 4, myonectin, irisin, and brain-derived neurotrophic factor (BDNF) all seem to have protective effects against obesity. The primary mechanism underlying the action of nesfatin-1 involves an increase in insulin sensitivity and reduced food intake. Neuregulin 4 sup-presses lipogenesis, decreases lipid accumulation, and reduces chronic low-grade inflammation. Myonectin lowers the amount of fatty acids in the bloodstream by increasing their absorption in the liver and AT. Irisin stimulates the browning of white adipose tissue (WAT) and consequently in-creases energy expenditure, additionally regulating glucose metabolism. Another molecule, BDNF, has anorexigenic effects. Decorin protects against the development of hyperglycemia, but may also contribute to proinflammatory processes. Similar effects are shown in the case of visfatin and chemerin, which may predispose to obesity. Visfatin increases adipogenesis, causes cholesterol accumulation in macrophages, and contributes to the development of glucose intolerance. Chemerin induces angiogenesis, which promotes the expansion of AT. This review aims to discuss the role of adipokines and myokines in the pathogenesis of the different obesity phenotypes.

Enteroendocrine cells and gut hormones as potential targets in the crossroad of the gut-kidney axis communication

Recent studies suggest that disruptions in intestinal homeostasis, such as changes in gut microbiota composition, infection, and inflammatory-related gut diseases, can be associated with kidney diseases. For instance, genomic investigations highlight how susceptibility genes linked to IgA nephropathy are also correlated with the risk of inflammatory bowel disease. Conversely, investigations demonstrate that the use of short-chain fatty acids, produced through fermentation by intestinal bacteria, protects kidney function in models of acute and chronic kidney diseases. Thus, the dialogue between the gut and kidney seems to be crucial in maintaining their proper function, although the factors governing this crosstalk are still emerging as the field evolves. In recent years, a series of studies have highlighted the significance of enteroendocrine cells (EECs) which are part of the secretory lineage of the gut epithelial cells, as important components in gut-kidney crosstalk. EECs are distributed throughout the epithelial layer and release more than 20 hormones in response to microenvironment stimuli. Interestingly, some of these hormones and/or their pathways such as Glucagon-Like Peptide 1 (GLP-1), GLP-2, gastrin, and somatostatin have been shown to exert renoprotective effects. Therefore, the present review explores the role of EECs and their hormones as regulators of gut-kidney crosstalk and their potential impact on kidney diseases. This comprehensive exploration underscores the substantial contribution of EEC hormones in mediating gut-kidney communication and their promising potential for the treatment of kidney diseases.

Role of Nucleobindin-2 in the Clinical Pathogenesis and Treatment Resistance of Glioblastoma

Glioblastoma (GBM) stands as the most prevalent primary malignant brain tumor, typically resulting in a median survival period of approximately thirteen to fifteen months after undergoing surgery, chemotherapy, and radiotherapy. Nucleobindin-2 (NUCB2) is a protein involved in appetite regulation and energy homeostasis. In this study, we assessed the impact of NUCB2 expression on tumor progression and prognosis of GBM. We further evaluated the relationship between NUCB2 expression and the sensitivity to chemotherapy and radiotherapy in GBM cells. Additionally, we compared the survival of mice intracranially implanted with GBM cells. High NUCB2 expression was associated with poor prognosis in patients with GBM. Knockdown of NUCB2 reduced cell viability, migration ability, and invasion ability of GBM cells. Overexpression of NUCB2 resulted in reduced apoptosis following temozolomide treatment and increased levels of DNA damage repair proteins after radiotherapy. Furthermore, mice intracranially implanted with NUCB2 knockdown GBM cells exhibited longer survival compared to the control group. NUCB2 may serve as a prognostic biomarker for poor outcomes in patients with GBM. Additionally, NUCB2 not only contributes to tumor progression but also influences the sensitivity of GBM cells to chemotherapy and radiotherapy. Therefore, targeting NUCB2 protein expression may represent a novel therapeutic approach for the treatment of GBM.

Estradiol and progesterone regulate NUCB2/nesfatin-1 expression and function in GH3 pituitary cells and THESC endometrial cells

Estradiol (E2) and progesterone (P4) are essential sex steroid hormones that play critical roles in the pituitary gland and uterus. Recently, nesfatin-1, a polypeptide hormone that regulates appetite and energy homeostasis in the hypothalamus, was found to be expressed in the pituitary gland and uterus. In this study, we aimed to investigate the relationship between these two steroid hormones and the expression and function of nesfatin-1 in the pituitary gland and uterus using GH3 cells, a lacto-somatotroph cell line, and THESC cells, an endometrial stromal cell line. First, we verified the presence of nesfatin-1 and nesfatin-1 binding sites in GH3 and THESC cells. E2 increased the mRNA expression of NUCB2, the gene encoding the nesfatin-1 protein, in GH3 cells, while P4 had no significant effect. In THESC cells, NUCB2 mRNA expression was decreased by E2 but increased by P4. In addition, nesfatin-1 significantly increased growth hormone (GH) and prolactin (PRL) mRNA expression in GH3 cells, and E2 enhanced this effect. In THESC cells, nesfatin-1 significantly increased the mRNA expression of insulin-like growth factor binding protein 1 (IGFBP1) and PRL, which are decidualization marker genes, and P4 further enhanced this effect. These results suggest that nesfatin-1 may act as a local regulator of GH and PRL production in the pituitary gland and decidualization in the uterus, modulating its effects in response to E2 and P4.

Neuropeptides Modulate Feeding via the Dopamine Reward Pathway

Dopamine (DA) is a catecholamine neurotransmitter widely distributed in the central nervous system. It participates in various physiological functions, such as feeding, anxiety, fear, sleeping and arousal. The regulation of feeding is exceptionally complex, involving energy homeostasis and reward motivation. The reward system comprises the ventral tegmental area (VTA), nucleus accumbens (NAc), hypothalamus, and limbic system. This paper illustrates the detailed mechanisms of eight typical orexigenic and anorexic neuropeptides that regulate food intake through the reward system. According to recent literature, neuropeptides released from the hypothalamus and other brain regions regulate reward feeding predominantly through dopaminergic neurons projecting from the VTA to the NAc. In addition, their effect on the dopaminergic system is mediated by the prefrontal cortex, paraventricular thalamus, laterodorsal tegmental area, amygdala, and complex neural circuits. Research on neuropeptides involved in reward feeding can help identify more targets to treat diseases with metabolic disorders, such as obesity.

Current state of phoenixin-the implications of the pleiotropic peptide in stress and its potential as a therapeutic target

Phoenixin is a pleiotropic peptide, whose known functions have broadened significantly over the last decade. Initially first described as a reproductive peptide in 2013, phoenixin is now recognized as being implicated in hypertension, neuroinflammation, pruritus, food intake, anxiety as well as stress. Due to its wide field of involvement, an interaction with physiological as well as psychological control loops has been speculated. It has shown to be both able to actively reduce anxiety as well as being influenced by external stressors. Initial rodent models have shown that central administration of phoenixin alters the behavior of the subjects when confronted with stress-inducing situations, proposing an interaction with the perception and processing of stress and anxiety. Although the research on phoenixin is still in its infancy, there are several promising insights into its functionality, which might prove to be of value in the pharmacological treatment of several psychiatric and psychosomatic illnesses such as anorexia nervosa, post-traumatic stress disorder as well as the increasingly prevalent stress-related illnesses of burnout and depression. In this review, we aim to provide an overview of the current state of knowledge of phoenixin, its interactions with physiological processes as well as focus on the recent developments in stress response and the possible novel treatment options this might entail.

Expression of phoenixin-14 and nesfatin-1 in the hypothalamo-pituitary-gonadal axis in the phases of the estrous cycle

Phoenixin-14 (PNX-14) and nucleobindin 2 (NUCB2)/nesfatin-1 are regulatory neuropeptides expressed in the hypothalamus. These neuropeptides can be effective in hormonal regulation of the hypothalamo-pituitary-gonadal (HPG) axis and reproductive functions. In the present study, the distribution of PNX-14 and NUCB2/nesfatin-1 in the hypothalamus, pituitary, ovary, and uterus tissues during the phases of the estrous cycle in female rats was investigated. Eighteen Wistar Albino rats determined among animals showing regular estrous cycle by vaginal smear method were divided into three groups: proestrus (Group I), estrus (Group II) and diestrus (Group III). Serum gonadotropin-releasing hormone (GnRH), plasma PNX-14, and NUCB2/nesfatin-1 concentrations were the highest, moderate, and lowest in estrus, diestrus, and proestrus phases, respectively. PNX-14 immunoreactivity in the supraoptic and arcuate nuclei of the hypothalamus and NUCB2/nesfatin-1 immunoreactivity in the paraventricular nuclei were particularly evident in the estrus phase. These neuropeptide immunoreactivities were decreased in different cells of anterior pituitary during proestrus compared with those during estrus and diestrus. PNX-14 immunoreactivity in the ovary, especially during the estrus phase, was diffuse and intense in the granulosa and luteal cells and oocytes, and it was few and weak in theca cells. In addition, NUCB2/nesfatin-1 immunoreactivity was abundant and strong in granulosa and luteal cells, theca and interstitial cells, and oocytes during estrus. In the estrus phase, PNX-14 immunoreactivity was strong in the glandular epithelial cells and stromal cells of the endometrium, also NUCB2/nesfatin-1 immunoreactivity was strong in the epithelial and glandular epithelial cells. As a result, when the estrous cycle was evaluated, it was concluded that the changes in the distribution of PNX-14 and NUCB2/nesfatin-1 at all phases were related to GnRH and that these neuropeptides showed the highest immunoreactivity especially in the HPG axis and uterus tissues of estrus rats.

Does NUCB2/Nesfatin-1 Influence Eating Behaviors in Obese Patients with Binge Eating Disorder? Toward a Neurobiological Pathway

Nesfatin-1 is a new anorexigenic neuropeptide involved in the regulation of hunger/satiety, eating, and affective disorders. We aimed to investigate nesfatin-1 secretion in vitro, in murine adipose cells, and in human adipose fat samples, as well as to assess the link between circulating nesfatin-1 levels, NUCB2 and Fat Mass and Obesity Gene (FTO) polymorphisms, BMI, Eating Disorders (EDs), and pathological behaviors. Nesfatin-1 secretion was evaluated both in normoxic fully differentiated 3T3-L1 mouse adipocytes and after incubation under hypoxic conditions for 24 h. Omental Visceral Adipose tissue (VAT) specimens of 11 obese subjects, and nesfatin-1 serum levels' evaluation, eating behaviors, NUCB2 rs757081, and FTO rs9939609 polymorphisms of 71 outpatients seeking treatment for EDs with different Body Mass Index (BMI) were studied. Significantly higher levels of nesfatin-1 were detected in hypoxic 3T3-L1 cultured adipocytes compared to normoxic ones. Nesfatin-1 was highly detectable in the VAT of obese compared to normal-weight subjects. Nesfatin-1 serum levels did not vary according to BMI, sex, and EDs diagnosis, but correlations with grazing; emotional, sweet, and binge eating; hyperphagia; social eating; childhood obesity were evident. Obese subjects with CG genotype NUCB2 rs757081 and AT genotype FTO rs9939609 polymorphisms had higher nesfatin-1 levels. It could represent a new biomarker of EDs comorbidity among obese patients.

NUCB2/nesfatin-1 is associated with severity of eating disorder symptoms in female patients with obesity

BACKGROUND

Nesfatin-1 has been described as an anorexigenic peptide. Comprehensive evidence also points towards an involvement of nesfatin-1 in the modulation of emotional pathways with a sex-specific regulation of nesfatin-1 in association with anxiety. Although the implication of nesfatin-1 in the regulation of food intake is well-established in animals, data in humans are lacking. Therefore, we investigated a possible association of circulating NUCB2/nesfatin-1 with eating disorder symptoms in female and male patients displaying a wide range of body weight.

METHODS

We enrolled 243 inpatients (177 female, 66 male) hospitalized due to anorexia nervosa (n = 66) or obesity (n = 144) or with normal weight and suffering from somatoform, adjustment, depressive or anxiety disorders (n = 33). Plasma samples (NUCB2/nesfatin-1 levels measured by ELISA) and measures of eating disorder symptoms (by EDI-2, range 0-100) were obtained within three days after admission.

RESULTS

The study population displayed a distinct prevalence of eating disorder symptoms with female patients with anorexia nervosa (+ 77.0%, p < 0.001) and obesity (+ 87.9%, p < 0.001) reported significantly higher EDI-2 scores than normal weight patients of the same sex. Accordingly, males with anorexia nervosa (+ 39.7%, p < 0.05) and obesity (+ 51.7%, p < 0.001) had significantly higher EDI-2 scores than males with normal weight. Within the same BMI group, women displayed significantly higher scores than men (+ 21.4%, p < 0.05 in patients with anorexia nervosa, + 18.8%, p < 0.001 in participants with obesity). We observed a positive correlation between NUCB2/nesfatin-1 levels and EDI-2 total scores in female patients with obesity (r = 0.285, p = 0.015), whereas no associations were found in other subgroups. A positive correlation between NUCB2/nesfatin-1 levels and BMI was only observed in the male study population (r = 0.315, p = 0.018).

CONCLUSIONS

NUCB2/nesfatin-1 plasma levels were positively associated with EDI-2 total scores in women with obesity, while no association was observable in men. The lacking association of NUCB2/nesfatin-1 and EDI-2 total scores in female patients with anorexia nervosa might be due to already low NUCB2/nesfatin-1 plasma levels. Whether NUCB2/nesfatin-1 is selectively involved in eating behavior in women with obesity will have to be further investigated.

The Actions of Centrally Administered Nesfatin-1 on Emesis, Feeding, and Locomotor Activity in Suncus murinus (House Musk Shrew)

Nesfatin-1 is an anorectic peptide expressed in both peripheral tissues and brain areas involved in the regulation of feeding, emotion and emesis. The aim of the present study is to characterize the distribution of NUCB2/nesfatin-1 in Suncus murinus and to investigate the actions of nesfatin-1 to affect gastrointestinal contractility, emesis, food and water intake, and locomotor activity. The deduced amino acid sequence of S. murinus nesfatin-1 using in silico cloning showed high homology with humans and rodents. NUCB2 mRNA was detected throughout the entire brain and in the gastrointestinal tract, including the stomach and gut. Western blot analysis and immunohistochemistry confirmed the expression of nesfatin-1 protein in these regions. The NUCB2 mRNA levels in the hypothalamus, hippocampus and brainstem were significantly decreased, whereas that in the striatum were increased after 24 h starvation compared to ad libitum-fed animals (p &lt; 0.05). In in vitro studies, nesfatin-1 (0.3–1,000 pM) failed to contract or relax the isolated gastric antrum and intestinal segments. In conscious, freely moving animals, intracerebroventricular administration of nesfatin-1 (1–50 pmol) induced emesis (p &lt; 0.05) and suppressed 6-h cumulative food intake (p &lt; 0.05), without affecting the latency to feeding. Nesfatin-1 (25 pmol, i.c.v.) decreased 24-h cumulative food and water intake by 28.3 and 35.4%, respectively (p &lt; 0.01). No significant differences in locomotor activity were observed. In conclusion, NUCB2/nesfatin-1 might be a potent regulator of feeding and emesis in S. murinus. Further studies are required to elucidate the mechanism of actions of this peptide as a mediator linking the brainstem NUCB2/nesfatin-1 to forebrain system.

"Sibling" battle or harmony: crosstalk between nesfatin-1 and ghrelin

Ghrelin was first identified as an endogenous ligand of the growth hormone secretagogue receptor (GHSR) in 1999, with the function of stimulating the release of growth hormone (GH), while nesfatin-1 was identified in 2006. Both peptides are secreted by the same kind of endocrine cells, X/A-like cells in the stomach. Compared with ghrelin, nesfatin-1 exerts opposite effects on energy metabolism, glucose metabolism, gastrointestinal functions and regulation of blood pressure, but exerts similar effects on anti-inflammation and neuroprotection. Up to now, nesfatin-1 remains as an orphan ligand because its receptor has not been identified. Several studies have shown the effects of nesfatin-1 are dependent on the receptor of ghrelin. We herein compare the effects of nesfatin-1 and ghrelin in several aspects and explore the possibility of their interactions.

Interactions between nesfatin-1 and the autonomic nervous system-An overview

Nesfatin-1, an 82-amino acid polypeptide derived from the precursor protein nucleobindin-2 (NUCB2), was first discovered in 2006 in the rat hypothalamus. The effects and distribution of nesfatin-1 immunopositive neurons in the brain and spinal cord point towards a role of NUCB2/nesfatin-1 in autonomic regulation. Therefore, studies which have been conducted to investigate the interplay between nesfatin-1 and the autonomic nervous system were examined, and the outcomes of this research were summarized. NUCB2/nesfatin-1 immunoreactivity is widely distributed in autonomic centers of the brain and spinal cord in both rodents and humans. In several regions of the hypothalamus, midbrain and brainstem, nesfatin-1 modulates autonomic functions. On the other hand, the autonomic nervous system also influences the activity of nesfatin-1 neurons. Here, the vagus nerve seems to be a crucial factor in the regulation of nesfatin-1. In summary, although data here is still sparse, there is a clear interplay between nesfatin-1 and the autonomic nervous system, the precise clarification of which still requires further research to gain more insight into these complex relationships.

Nesfatin-1 treatment preserves antioxidant status and attenuates renal fibrosis in rats with unilateral ureteral obstruction

BACKGROUND

Nesfatin-1 (NES-1), an anorexigenic peptide, was reported to have anti-inflammatory and anti-apoptotic actions in several inflammation models.

METHODS

To elucidate potential renoprotective effects of NES-1, unilateral ureteral obstruction (UUO) was induced in male Sprague Dawley rats by ligating left ureters. The rats were injected intraperitoneally with either saline (SL) or NES-1 (10 μg/kg/day) for 7 or 14 days (n = 8 in each group). On the 7th or 14th day, obstructed kidneys were removed for the isolation of leukocytes for flow-cytometric analysis and for the assessments of biochemical and histopathological changes.

RESULTS

Opposite to glutathione levels, renal myeloperoxidase activity in the SL-treated UUO group was significantly increased compared to sham-operated group, while NES-1 treatment abolished the elevation. The percentages of CD8+/CD4+ T-lymphocytes infiltrating the obstructed kidneys were increased in SL-treated groups but treatment with NES-1 did not prevent lymphocyte infiltration. Elevated TNF-a levels in SL-treated UUO group was decreased with NES-1. Although total degeneration scores were similarly increased in all UUO groups, tubular dilatation scores were significantly increased in UUO groups and lowered by NES-1 only in the 7-day treated group. Elevated interstitial fibrosis scores in the SL-treated groups were decreased in both 7- and 14-day NES-1 treated groups, while alpha smooth muscle actin (α-SMA) and apoptosis scores were depressed in both NES-1 treated groups.

CONCLUSION

The present data demonstrate that UUO-induced renal fibrosis is ameliorated by NES-1, which appears to involve the inhibition of neutrophil infiltration and thereby amelioration of oxidative stress and inflammation. These data suggest that NES-1 may have a regulatory role in protecting the kidneys against obstruction-induced renal injury.

Minireview: Peripheral Nesfatin-1 in Regulation of the Gut Activity—15 Years since the Discovery

Simple Summary

Nesfatin-1 is a newly identified molecule derived from the precursor protein NEFA/nucleobindin2. In this minireview we analyzed the research on the nesfatin-1 localization in the gastrointestinal tract of the mammals. We also referred to the effects of the protein on disorders in the gastrointestinal tract.

Abstract

Nesfatin-1, discovered in 2006, is an anorexigenic molecule derived from the precursor protein NEFA/nucleobindin2. It is generally postulated that this molecule acts through a specific G protein-coupled receptor, as yet unidentified. Research conducted over the last 15 years has revealed both central and peripheral actions of nesfatin-1. Given its major central role, studies determining its inhibitory effect on food intake seem to be of major scientific interest. However, in recent years a number of experiments have found that peripheral organs, including those of the gastrointestinal tract (GIT), may also be a source (possibly even the predominant source) of nesfatin-1. This mini-review aimed to summarize the current state of knowledge regarding the expression and immunoreactivity of nesfatin-1 and its possible involvement (both physiological and pathological) in the mammalian GIT. Research thus far has shown very promising abilities of nesfatin-1 to restore the balance between pro-oxidants and antioxidants, to interplay with the gut microbiota, and to alter the structure of the intestinal barrier. This necessitates more extensive research on the peripheral actions of this molecule. More in-depth knowledge of such mechanisms (especially those leading to anti-inflammatory and anti-apoptotic effects) is important for a better understanding of the involvement of nefatin-1 in GIT pathophysiological conditions and/or for future therapeutic approaches.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus-pituitary-gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

Nucleobindin-derived nesfatin-1 and nesfatin-1-like peptide stimulate pro-opiomelanocortin synthesis in murine AtT-20 corticotrophs through the cAMP/PKA/CREB signaling pathway

Nucleobindin (NUCB)-derived peptides, nesfatin-1 (NES-1) and nesfatin-1-like peptide (NLP) have several physiological roles in vertebrates. While NES-1 is implicated in stress, whether NUCB1/NLP and NUCB2/NES-1 have any effect on proopiomelanocortin (POMC) remains unknown. The main aim of this study was to determine if NES-1 and/or NLP affect POMC synthesis in mouse corticotrophs. Immunocytochemistry was employed to target NUCB colocalization with POMC in immortalized mouse tumoral corticotrophs (AtT-20 cells). The ability of NES-1 and NLP to modulate POMC mRNA and protein in AtT-20 cells was assessed by qPCR and Western blot, respectively. Moreover, cell-signaling molecules mediating the effect of NES-1 and NLP on POMC synthesis in mouse tumoral corticotrophs were studied using pharmacological blockers. Mouse tumoral corticotrophs showed immunoreactivity for both NUCB1/NLP and NUCB2/NES-1. Both NES-1 and NLP exerted a stimulatory effect on POMC transcript abundance and protein expression in a dose- and time-dependent manner. This effect was comparable to corticotropin-releasing factor (CRF, positive control) stimulation of POMC. Incubation of mouse tumoral corticotrophs with NES-1 or NLP upregulated the phosphorylation of protein kinase A (PKA) and cAMP-response element-binding protein (CREB). The stimulatory effect of these peptides on POMC transcript abundance and protein expression was blocked by the PKA inhibitor, H89, and an adenylate cyclase inhibitor, 2',3'-dideoxyadenosine (DDA). These pharmacological studies indicate that NES-1 and NLP act through the cAMP/PKA/CREB cellular pathway to stimulate POMC synthesis. Our results provide molecular evidence to support a stimulatory role for nucleobindin-derived peptides on POMC synthesis from corticotrophs. Collectively, this research indicates that corticotrophs produce NUCBs, and the encoded peptides NES-1 and NLP could elicit a direct action to stimulate the pituitary stress hormone. This stimulatory effect is mediated by an uncharacterized G protein-coupled receptor (GPCR) that utilizes the cAMP/PKA/CREB pathway.

A comparative account of nesfatin-1 in vertebrates

Nesfatin-1 was discovered as an anorexigenic peptide derived from proteolytic cleavage of the prepropeptide, nucleobindin 2 (NUCB2). It is widely expressed in central as well as peripheral tissues and is known to have pleiotropic effects such as regulation of feeding, reproduction, cardiovascular functions and maintenance of glucose homeostasis. In order to execute its multifaceted role, nesfatin-1 employs diverse signaling pathways though its receptor has not been identified till date. Further, nesfatin-1 is reported to be under the regulatory effect of feeding state, nutritional status as well as several metabolic and reproductive hormones. This peptide has also been associated with variety of human diseases, especially metabolic, reproductive, cardiovascular and mental disorders. The current review is aimed to present a consolidated picture and highlight lacunae for further investigation in order to develop a deeper comprehensive understanding on physiological significance of nesfatin-1 in vertebrates.

Nesfatin-1 is an inhibitor of the growth hormone-insulin-like growth factor axis in goldfish (Carassius auratus)

Nesfatin-1, an 82 amino acid peptide cleaved from the N-terminal of its precursor nucleobindin-2 (NUCB2), is emerging as a multifunctional peptide in fish. The present study aimed to determine whether nesfatin-1 plays a role in fish somatic growth by modulating the growth hormone (GH)/insulin-like growth factor (IGF) axis, using a representative teleost model, the goldfish (Carassius auratus). The results demonstrated that a single i.p. injection of synthetic goldfish nesfatin-1 significantly decreased the expression of hypothalamic pacap (approximately 90%) and pituitary Gh (approximately 90%) mRNAs at 15 minutes post-injection. Serum GH levels were also reduced as a result of nesfatin-1 administration, by approximately 45% and 55% at 15 and 30 minutes post-injection, respectively. Likewise, in vitro treatment of goldfish dispersed pituitary cells with nesfatin-1 reduced Gh secretion, suggesting that nesfatin-1 acts directly on pituitary somatotrophs to inhibit Gh release. Exposure of cultured liver fragments to nesfatin-1 (0.1, 1 and 10 nmol L^-1 ) led to a significant reduction in igf-1 mRNA at 120 minutes and of igf-II mRNA at 30 and 60 minutes post-incubation. Collectively, these results indicate a suppressive role for nesfatin-1 on the goldfish GH/IGF axis. Immunohistochemical studies demonstrated that NUCB2/nesfatin-1-like immunoreactivity, although present in the goldfish pituitary, is not colocalised with GH in goldfish somatotrophs. Thus, nesfatin-1 does not appear to act in an autocrine manner to regulate GH secretion. Taken together, this research found that the pituitary gland is an important source of endogenous NUCB2/nesfatin-1 and also that nesfatin-1 directly suppresses the Gh/IGF axis in goldfish.

Role of the Novel Peptide Phoenixin in Stress Response and Possible Interactions with Nesfatin-1

The novel peptide phoenixin was shown to be involved in several physiological processes ranging from reproduction to food intake. Interest in this protein has steadily increased over the last few years and its known implications have become much broader, playing a role in glucose homeostasis, anxiety, nociception, and pruritus. Phoenixin is expressed in a multitude of organs such as the small intestine, pancreas, and in the hypothalamus, as well as several other brain nuclei influencing numerous physiological functions. Its highly conserved amino-acid sequence amongst species leads to the assumption, that phoenixin might be involved in essential physiological functions. Its co-expression and opposing functionality to the extensively studied peptide nesfatin-1 has given rise to the idea of a possible counterbalancing role. Several recent publications focused on phoenixin’s role in stress reactions, namely restraint stress and lipopolysaccharide-induced inflammation response, in which also nesfatin-1 is known to be altered. This review provides an overview on the phoenixins and nesfatin-1 properties and putative effects, and especially highlights the recent developments on their role and interaction in the response to response.

Centrally Projecting Edinger-Westphal Nucleus in the Control of Sympathetic Outflow and Energy Homeostasis

The centrally projecting Edinger-Westphal nucleus (EWcp) is a midbrain neuronal group, adjacent but segregated from the preganglionic Edinger-Westphal nucleus that projects to the ciliary ganglion. The EWcp plays a crucial role in stress responses and in maintaining energy homeostasis under conditions that require an adjustment of energy expenditure, by virtue of modulating heart rate and blood pressure, thermogenesis, food intake, and fat and glucose metabolism. This modulation is ultimately mediated by changes in the sympathetic outflow to several effector organs, including the adrenal gland, heart, kidneys, brown and white adipose tissues and pancreas, in response to environmental conditions and the animal's energy state, providing for appropriate energy utilization. Classic neuroanatomical studies have shown that the EWcp receives inputs from forebrain regions involved in these functions and projects to presympathetic neuronal populations in the brainstem. Transneuronal tracing with pseudorabies virus has demonstrated that the EWcp is connected polysynaptically with central circuits that provide sympathetic innervation to all these effector organs that are critical for stress responses and energy homeostasis. We propose that EWcp integrates multimodal signals (stress, thermal, metabolic, endocrine, etc.) and modulates the sympathetic output simultaneously to multiple effector organs to maintain energy homeostasis under different conditions that require adjustments of energy demands.

The intermediary role of the central cyclooxygenase / lipoxygenase enzymes in intracerebroventricular injected nesfatin-1-evoked cardiovascular effects in rats

That nesfatin-1 is a neuromodulatory peptide for the cardiovascular system is well documented. Several central receptors have been shown to mediate the cardiovascular effects of nesfatin-1. Immunohistochemistry and Western blot studies showed that nesfatin-1 activated the expression of the central cyclooxygenase (COX) -1, -2 and lipoxygenase (LOX). In addition, microdialysis study showed that nesfatin-1 increased the release of total prostaglandins and leukotrienes from the hypothalamus. The present study investigated whether the central COX and LOX enzymes have a direct mediating role in the MAP and HR responses of nesfatin-1. Intracerebroventricularly administered nesfatin-1 produced dose-dependent pressor and phasic HR responses in normotensive conscious rats Sprague Dawley. Central pretreatment with a COX1/2 inhibitor, ibuprofen, completely blocked the nesfatin-1-induced responses. However, central pretreatment with a nonselective LOX inhibitor, nordihydroguaiaretic acid, partially attenuated the cardiovascular responses induced by nesfatin-1. The results suggest that centrally administered nesfatin-1 activates the central enzymes COX and LOX, which may be involved in the cardiovascular responses as a novel central mechanism for nesfatin-1.

High-fat Diet Enhances Gastric Contractility, but Abolishes Nesfatin-1-induced Inhibition of Gastric Emptying

BACKGROUND/AIMS

Gastrointestinal motility changes contribute to development and maintenance of obesity. Nesfatin-1 (NES-1) is involved in central appetite control. The aim is to elucidate effects of NES-1 and high-fat diet (HFD) on gastrointestinal motility and to explore myenteric neuron expressions of tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), and neuronal nitric oxide synthase (nNOS) in HFDinduced oxidative injury.

METHODS

Sprague-Dawley rats were fed with normal diet (ND) or HFD. Gastric emptying rate was measured following NES-1 (5 pmol/rat, intracerebroventricular) preceded by subcutaneous injections of glucagon-like peptide 1 (GLP-1), cholecystokinin 1 (CCK-1), and gastrin/CCK-2 receptor antagonists. In carbachol-contracted gastric and ileal strips, contractile changes were recorded by adding NES- 1 (0.3 nmol/L), GLP-1, CCK-1, and gastrin/CCK-2 antagonists.

RESULTS

Neither HFD nor NES-1 changed methylcellulose emptying, but NES-1 delayed saline emptying in cannulated ND-rats. Inhibitory effect of NES-1 on gastric emptying in ND-rats was reversed by all antagonists, and abolished in HFD-rats. In HFD-rats, carbachol-induced contractility was enhanced in gastric, but inhibited in ileal strips. HFD increased body weight, while serum triglycerides, alanine transaminase, aspartate aminotransferase, glucose, and levels of malondialdehyde, glutathione, myeloperoxidase activity, and luminolchemiluminescence in hepatic, ileal, and adipose tissues were similar in ND- and HFD-rats, but only lucigenin-chemiluminescence was increased in HFD-rats. Vasoactive intestinal peptide (VIP) and TH immunoreactivities were depressed and nNOS immunoreactivity was increased in gastric tissues of HFD-rats, while VIP and TH were enhanced, but nNOS was reduced in their intestines.

CONCLUSIONS

HFD caused mild systemic inflammation, disrupted enteric innervation, enhanced gastric contractility, inhibited ileal contractility, and eliminated inhibitory effect of NES-1 on gastric motility.

Neuroendocrine Peptides of the Gut and Their Role in the Regulation of Food Intake

The regulation of food intake encompasses complex interplays between the gut and the brain. Among them, the gastrointestinal tract releases different peptides that communicate the metabolic state to specific nuclei in the hindbrain and the hypothalamus. The present overview gives emphasis on seven peptides that are produced by and secreted from specialized enteroendocrine cells along the gastrointestinal tract in relation with the nutritional status. These established modulators of feeding are ghrelin and nesfatin-1 secreted from gastric X/A-like cells, cholecystokinin (CCK) secreted from duodenal I-cells, glucagon-like peptide 1 (GLP-1), oxyntomodulin, and peptide YY (PYY) secreted from intestinal L-cells and uroguanylin (UGN) released from enterochromaffin (EC) cells. © 2021 American Physiological Society. Compr Physiol 11:1679-1730, 2021.

Loss of Nucleobindin-2/Nesfatin-1 increases lipopolysaccharide-induced murine acute lung inflammation

NUCB2/nesfatin-1 is expressed in variety of tissues. Treatment with nesfatin-1 reduces inflammation in rat models of subarachnoid hemorrhage-induced oxidative brain damage and traumatic brain injury as well as myocardial injury. There is only one study showing anti-inflammatory actions of nesfatin-1 on acute lung inflammation. To more precisely determine the role of NUCB2/nesfatin-1 in acute lung inflammation, we conducted a study using NUCB2/nesfatin-1 knockout (NKO) mice as well as neutrophils isolated from the bone marrows of WT and NKO mice. Our findings suggest that the absence of NUCB2/nesfatin-1 significantly increases the accumulation of adherent neutrophils by approximately 3 times compared with WT within LPS-treated lungs. Integrating this with observations from both BALF and neutrophil cytokine expression, we propose that although neutrophils lacking NUCB2/nesfatin-1 individually secrete less pro-inflammatory cytokines compared with stimulated WT cells, the result of knocking out NUCB2/nesfatin-1 is net pro-inflammatory. No change was found in NUCB2/nesfatin-1 mRNA or protein expression comparing WT LPS and PBS-treated samples. Taken together, our results show that NUCB2/nesfatin-1 is constitutively expressed in mouse lungs and neutrophils and demonstrates anti-inflammatory properties in mouse lungs during acute lung injury, by inhibiting adherent neutrophil accumulation and inflammatory cytokine expression.

Nesfatin-1 Receptor: Distribution, Signaling and Increasing Evidence for a G Protein-Coupled Receptor - A Systematic Review

BACKGROUND

Nesfatin-1 is an 82-amino acid polypeptide, cleaved from the 396-amino acid precursor protein nucleobindin-2 (NUCB2) and discovered in 2006 in the rat hypothalamus. In contrast to the growing body of evidence for the pleiotropic effects of the peptide, the receptor mediating these effects and the exact signaling cascades remain still unknown.

METHODS

This systematic review was conducted using a search in the Embase, PubMed, and Web of Science databases. The keywords "nesfatin-1" combined with "receptor", "signaling", "distribution", "pathway", g- protein coupled receptor", and "binding" were used to identify all relevant articles reporting about potential nesfatin-1 signaling and the assumed mediation via a G_i protein-coupled receptor.

RESULTS

Finally, 1,147 articles were found, of which 1,077 were excluded in several steps of screening, 70 articles were included in this systematic review. Inclusion criteria were studies investigating nesfatin-1's putative receptor or signaling cascade, observational preclinical and clinical studies, experimental studies, registry-based studies, cohort studies, population-based studies, and studies in English language. After screening for eligibility, the studies were assigned to the following subtopics and discussed regarding intracellular signaling of nesfatin-1 including the potential receptor mediating these effects and downstream signaling of the peptide.

CONCLUSION

The present review sheds light on the various effects of nesfatin-1 by influencing several intracellular signaling pathways and downstream cascades, including the peptide's influence on various hormones and their receptors. These data point towards mediation via a G_i protein-coupled receptor. Nonetheless, the identification of the nesfatin-1 receptor will enable us to better investigate the exact mediating mechanisms underlying the different effects of the peptide along with the development of agonists and antagonists.

Restraint stress affects circulating NUCB2/nesfatin-1 and phoenixin levels in male rats

The two peptides phoenixin and nesfatin-1 are colocalized in hypothalamic nuclei involved in the mediation of food intake and behavior. Phoenixin stimulates food intake and is anxiolytic, while nesfatin-1 is an anorexigenic peptide shown to increase anxiety and anhedonia. Interestingly, central activation of both peptides can be stimulated by restraint stress giving rise to a role in the mediation of stress. Thus, the aim of the study was to test whether also peripheral circulating levels of NUCB2/nesfatin-1 and phoenixin are altered by restraint stress. Male ad libitum fed Sprague Dawley rats equipped with a chronic intravenous catheter were subjected to restraint stress and plasma levels of NUCB2/nesfatin-1, phoenixin and cortisol were measured over a period of 240 min and compared to levels of freely moving rats. Peripheral cortisol levels were significantly increased in restrained rats at 30, 60, 120 and 240 min compared to controls (p < 0.05). In contrast, restraint stress decreased plasma phoenixin levels at 15 min compared to unstressed conditions (0.8-fold, p < 0.05). Circulating NUCB2/nesfatin-1 levels were increased only at 240 min in restrained rats compared to those in unstressed controls (1.3-fold, p < 0.05). In addition, circulating NUCB2/nesfatin-1 levels correlated positively with phoenixin levels (r = 0.378, p < 0.001), while neither phoenixin nor nesfatin-1 were associated with cortisol levels (r = 0.0275, and r=-0.143, p> 0.05). These data suggest that both peptides, NUCB2/nesfatin-1 and phoenixin, are affected by restraint stress, although less pronounced than circulating cortisol.

Nesfatin-1 ameliorates oxidative bowel injury in rats with necrotizing enterocolitis: The role of the microbiota composition and claudin-3 expression

BACKGROUND AND PURPOSE

Ongoing high mortality due to necrotizing enterocolitis (NEC) necessitates the investigation of novel treatments to improve the outcome of the affected newborns. The aim was to elucidate the potential therapeutic impact of the nesfatin-1, a peptide with anti-inflammatory and anti-apoptotic effects in several inflammatory processes, on NEC-induced newborn rats.

MATERIALS AND METHODS

Sprague-Dawley pups were separated from their mothers, fed with a hyperosmolar formula and exposed to hypoxia, while control pups had no intervention. NEC-induced pups received saline or nesfatin-1 (0.2 μg/kg/day) for 3 days, while some nesfatin-1 treated pups were injected with capsaicin (50 μg/g) for the chemical ablation of afferent neurons. On the 4th day, clinical state and macroscopic gut assessments were made. In intestines, immunohistochemical staining of cycloxygenase-2 (COX-2), nuclear factor (NF)-κB-p65 (RelA), vascular endothelial growth factor (VEGF), claudin-3 and zonula occludens-1 (ZO-1) were performed, while gene expressions of COX-2, occludin, claudin-3, NF-κB-p65 (RelA) and VEGF were determined using q-PCR. In fecal samples, relative abundance of bacteria was quantified by q-PCR. Biochemical evaluation of oxidant/antioxidant parameters was performed in both intestinal and cerebral tissues.

RESULTS

Claudin-3 and ZO-1 immunoreactivity scores were significantly elevated in the nesfatin-1 treated control pups. Nesfatin-1 reduced NEC-induced high macroscopic and clinical scores, inhibited NF-κB-65 pathway and maintained the balance of oxidant/antioxidant systems. NEC increased the abundance of Proteobacteria with a concomitant reduction in Actinobacteria and Bacteroidetes, while nesfatin-1 treatment reversed these alterations. Modulatory effects of nesfatin-1 on microbiota and oxidative injury were partially reversed by capsaicin. Immunohistochemistry demonstrated that nesfatin-1 abolished NEC-induced reduction in claudin-3. Gene expressions of COX-2, NF-κB, occludin and claudin-3 were elevated in saline-treated NEC pups, while these up-regulated mRNA levels were not further altered in nesfatin-1-treated NEC pups.

CONCLUSION

Nesfatin-1 could be regarded as a potential preventive agent for the treatment of NEC.

Nesfatin-1 and nesfatin-1-like peptide suppress growth hormone synthesis via the AC/PKA/CREB pathway in mammalian somatotrophs

Nesfatin-1 (NESF) and NESF-like peptide (NLP), encoded in nucleobindin 2 and 1 (NUCB2 and NUCB1), respectively, are orphan ligands and metabolic factors. We hypothesized that NESF and NLP suppress growth hormone (GH) synthesis, and aimed to determine whether mammalian somatotrophs are a source and site of action of these peptides. Using immortalized rat somatotrophs (GH3 cells), NUCB expression was determined by qPCR, immunofluorescence and Western blot. NESF and NLP binding to GH3 cells was tested using fluorescence imaging. Both time- and concentration-dependent studies were performed to test whether NESF and NLP affect GH. Moreover, the ability of these peptides to modulate the effects of ghrelin, and cell-signaling pathways were studied. GH3 cells express NUCB mRNAs and protein. Labeled NESF and NLP bind to the surface of GH3 cells, and incubation with either NESF or NLP decreased GH mRNA and protein expression, downregulated pit-1 mRNA, and blocked the GH stimulatory effects of ghrelin. Pre-incubation with either of these peptides reduced CREB phosphorylation by an AC-activator, but not when PKA was directly activated by a cAMP analog. Our results indicate that rat somatotrophs are a source of NUCBs, and that NESF and NLP downregulate GH synthesis through the AC/PKA/CREB signaling pathway.

Endogenous NUCB2/Nesfatin-1 Regulates Energy Homeostasis Under Physiological Conditions in Male Rats

Nesfatin-1 is the proteolytic cleavage product of Nucleobindin 2, which is expressed both in a number of brain nuclei (e. g., the paraventricular nucleus of the hypothalamus) and peripheral tissues. While Nucleobindin 2 acts as a calcium binding protein, nesfatin-1 was shown to affect energy homeostasis upon central nervous administration by decreasing food intake and increasing thermogenesis. In turn, Nucleobindin 2 mRNA expression is downregulated in starvation and upregulated in the satiated state. Still, knowledge about the physiological role of endogenous Nucleobindin 2/nesfatin-1 in the control of energy homeostasis is limited and since its receptor has not yet been identified, rendering pharmacological blockade impossible. To overcome this obstacle, we tested and successfully established an antibody-based experimental model to antagonize the action of nesfatin-1. This model was then employed to investigate the physiological role of endogenous Nucleobindin 2/nesfatin-1. To this end, we applied nesfatin-1 antibody into the paraventricular nucleus of satiated rats to antagonize the presumably high endogenous Nucleobindin 2/nesfatin-1 levels in this feeding condition. In these animals, nesfatin-1 antibody administration led to a significant decrease in thermogenesis, demonstrating the important role of endogenous Nucleobindin 2/nesfatin-1in the regulation of energy expenditure. Additionally, food and water intake were significantly increased, confirming and complementing previous findings. Moreover, neuropeptide Y was identified as a major downstream target of endogenous Nucleobindin 2/nesfatin-1.

NUCB2/nesfatin-1 - Inhibitory effects on food intake, body weight and metabolism

Since its discovery in 2006 by Oh-I and colleagues, NUCB2/nesfatin-1 encoded by nucleobindin-2 (NUCB2) has drawn sustained attention as reflected in over 500 publications. Among those, more than half focused on the alterations of food intake, body weight and metabolism (glucose, fat) induced by nesfatin-1 and/or NUCB2/nesfatin-1. In the current review we discuss the existing literature focusing on NUCB2/nesfatin-1's influence on food intake, body weight and glucose as well as fat metabolism and highlight gaps in knowledge.

17Beta-Estradiol Regulates NUCB2/ Nesfatin-1 Expression in Mouse Oviduct

NUCB2/nesfatin-1 known to regulate appetite and energy homeostasis is expressed not only in the hypothalamus, but also in various organs and tissues. Our previous reports also demonstrated that NUCB2/nesfatin-1 was expressed in the reproductive organs, including the ovaries, uterus, and testes of mice. However, it is yet known whether NUCB2/nesfatin-1 is expressed in the oviduct and how its expression is regulated. Therefore, we investigated the expression of NUCB2/nesfatin-1 in the oviduct and its expression is regulated by gonadotropin. Immunohistochemical staining results showed that nesfatin-1 protein was localized in epithelial cells of the oviduct. As a result of quantitative real-time PCR (qRT-PCR) and Western blot, NUCB2/nesfatin-1 was detected strongly in the oviducts. During the estrus cycle, NUCB2/nesfatin-1 expression in the oviducts was markedly higher in the proestrus stage than in other estrus stages. In order to elucidate whether the expression of NUCB2 mRNA is controlled by the gonadotropins, we injected PMSG and hCG and measured NUCB2 mRNA level in the oviduct after injection. Its level was increased in the oviduct after PMSG injection, but no significant change after hCG injection. In addition, NUCB2 mRNA levels were markedly reduced after ovariectomy, while recovered after 17β-estradiol (E2) injection, but not by progesterone (P4). This study demonstrated that NUCB2/nesfatin-1 is highly expressed in the oviduct of mouse and its expression is regulated by E2 secreted by the ovaries. These results suggest that NUCB2/nesfatin-1 expressed by the oviduct may affect the function of the oviduct regulated by the ovaries.

Intracerebroventricularly injected nesfatin-1 activates central cyclooxygenase and lipoxygenase pathways

Nesfatin-1 is a multifunctional neuropeptide having crucial autonomic roles. It is well known that nesfatin-1 collaborates with other central neuromodulatory systems, such as central corticotropin-releasing hormone, melanocortin, oxytocin, and cholinergic systems to show its autonomic effects. Central arachidonic acid cascade plays an important role to provide the homeostasis by exhibiting similar autonomic effects to nesfatin-1. Based on these similarities, the current study was designed to show the effects of intracerebroventricularly (ICV) injected nesfatin-1 on the hypothalamic arachidonic acid (AA) cascade. Immunochemistry and western blot approaches demonstrated that ICV administration of nesfatin-1 provokes an increase in the hypothalamic cyclooxygenase (COX) -1, -2 and lipoxygenase (LOX) protein expression. Moreover, the microdialysis study demonstrated that centrally injected nesfatin-1 increased the posterior hypothalamic extracellular AA products. In conclusion, these findings report that while nesfatin-1 is generating its autonomic effects, it also might be using central prostaglandins and leukotrienes by activating central COX and LOX pathways.

Nesfatin-1 in cardiovascular orchestration: From bench to bedside

Since the discovery of Nesfatin-1 in 2006, intensive research was finalized to further and deeper investigate the precise physiological functions of the peptide at both central and peripheral levels, rapidly enriching the knowledge regarding this intriguing molecule. Nesfatin-1 is a hypothalamic peptide generated via the post-translational processing of its precursor Nucleobindin 2, a protein supposed to play a role in many biological processes thanks to its ability to bind calcium and to interact with different intracellular proteins. Nesfatin-1 is mainly known for its anorexic properties, but it also controls water intake and glucose homeostasis. Recent experimental evidences describe the peptide as a possible direct/indirect orchestrator of central and peripheral cardiovascular control. A specific Nesfatin-1 receptor still remains to be identified although numerous studies suggest that the peptide activates extra- and intracellular regulatory pathways by involving several putative binding sites. The present paper was designed to systematically review the latest findings about Nesfatin-1, focusing on its cardiovascular regulatory properties under normal and physiopathological conditions. The hope is to provide the conceptual basis to consider Nesfatin-1 not only as a pleiotropic neuroendocrine molecule, but also as a homeostatic modulator of the cardiovascular function and with a crucial role in cardiovascular diseases.

Adipocytes-released Peptides Involved in the Control of Gastrointestinal Motility

The present review focuses on adipocytes-released peptides known to be involved in the control of gastrointestinal motility, acting both centrally and peripherally. Thus, four peptides have been taken into account: leptin, adiponectin, nesfatin-1, and apelin. The discussion of the related physiological or pathophysiological roles, based on the most recent findings, is intended to underlie the close interactions among adipose tissue, central nervous system, and gastrointestinal tract. The better understanding of this complex network, as gastrointestinal motor responses represent peripheral signals involved in the regulation of food intake through the gut-brain axis, may also furnish a cue for the development of either novel therapeutic approaches in the treatment of obesity and eating disorders or potential diagnostic tools.

Nucleobindins and encoded peptides: From cell signaling to physiology

Nucleobindins (NUCBs) are DNA and calcium binding, secreted proteins with various signaling functions. Two NUCBs, nucleobindin-1 (NUCB1) and nucleobindin-2 (NUCB2), were discovered during the 1990s. These two peptides are shown to have diverse functions, including the regulation of inflammation and bone formation, among others. In 2006, Oh-I and colleagues discovered that three peptides encoded within the NUCB2 could be processed by prohormone convertases. These peptides were named nesfatin-1, 2 and 3, mainly due to the satiety and fat influencing properties of nesfatin-1. However, it was found that nesfatin-2 and -3 have no such effects. Nesfatin-1, especially its mid-segment, is very highly conserved across vertebrates. Although the receptor(s) that mediate nesfatin-1 effects are currently unknown, it is now considered an endogenous peptide with multiple functions, affecting central and peripheral tissues to regulate metabolism, reproduction, endocrine and other functions. We recently identified a nesfatin-1-like peptide (NLP) encoded within the NUCB1. Like nesfatin-1, NLP suppressed feed intake in mice and fish, and stimulated insulin secretion from pancreatic beta cells. There is considerable evidence available to indicate that nucleobindins and its encoded peptides are multifunctional regulators of cell biology and whole animal physiology. This review aims to briefly discuss the structure, distribution, functions and mechanism of action nucleobindins and encoded peptides.

Role of nesfatin-1 in anxiety, depression and the response to stress

Nesfatin-1 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 nesfatin-1 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.

SERUM NESFATIN-1 LEVEL IN HEALTHY SUBJECTS WITH WEIGHT-RELATED ABNORMALITIES AND NEWLY DIAGNOSED PATIENTS WITH TYPE 2 DIABETES MELLITUS; A CASE-CONTROL STUDY

Context

Nesfatin-1 is a novel peptide with both central and peripheral anorexigenic regulatory properties. Besides its effects on food intake, few studies have suggested a possible role for this peptide in the pathogenesis of diabetes mellitus type 2.

Objective

To compare serum levels of nesfatin-1 between healthy, normal-weight persons and three groups including healthy underweight, healthy obese and diabetic subjects.

Design

Prospective, case-control study, performed between January 2015 and January 2016.

Subjects and Methods

Fasting levels in serum nesfatin-1 were measured in 30 healthy, normal-weight individuals (controls), 30 healthy underweight persons, 30 healthy obese persons, and 30 patients with newly diagnosed diabetes type 2 using standard enzyme-linked immunosorbent assay (ELISA) kits.

Results

The mean serum nesfatin-1 level was significantly higher in controls (2.61 ng/mL) compared to that in obese (1.13 ng/mL) and diabetic (0.99 ng/mL) patients; and significantly lower than that in the underweight group (3.50 ng/mL). The obese and diabetic groups were comparable in this regard. No significant association was found between serum nesfatin-1 level and age, sex, or body mass index.

Conclusions

Serum nesfatin-1 is possibly associated with weight-related abnormalities in otherwise healthy subjects and diabetes type 2. Obesity and diabetes type 2 may share a common pathologic point in this regard.

Tissue-Specific Localization NUCB2/nesfatin-1 in the Liver and Heart of Mouse Fetus

NUCB2/nesfatin-1 is first known to be expressed in the hypothalamus while controlling appetite and energy metabolism. However, recent studies have shown that NUCB2/nesfatin-1 was expressed in the various organs as well as the hypothalamus. Our previous reports also demonstrated that NUCB2/nesfatin-1 was expressed in the ovary, testis, pituitary gland, lung, kidney, and stomach of fetal and adult mice. However, the role of NUCB2/nesfatin-1 in mouse fetus remains unknown. Thus, the aim of this study was to investigate whether NUCB2/nestatin-1 is expressed in mouse fetus at the developmental stage in which organogenesis begins. To do this, we performed in situ hybridization (ISH) and immunohistochemistry (IHC) staining to examine the distribution of NUCB2 mRNA and nesfatin-1 protein in the mouse fetal organs during early developmental stages, especially at embryonic day (E) 10.5. As a result of ISH, NUCB2 mRNA positive signals were more frequent in the liver, but there were relatively few positive signals in heart. On the other hand, no positive signals were detected in other organs. These ISH results were validated by IHC staining and qRT-PCR analysis. Expression of nesfatin-1 protein detected by IHC staining was similar to that of NUCB2 mRNA detected by ISH in the liver and heart. In addition, the levels of NUCB2 mRNA expression analyzed by qRT-PCR were significantly increased in the liver and heart compared to other organs of the mouse fetus at E13.5, whereas its level was extensively decreased in the liver, but increased in the lung, stomach, and kidney of the mouse fetus at E17.5. These results suggest that NUCB2/nesfatin-1 may play an important role in liver and heart development and physiological functions in the developmental process of mouse fetus. Further studies are needed on the function of NUCB2/nesfatin-1, which is highly expressed in the various organs, including liver and heart during mouse development.

Nesfatin-130-59 Injected Intracerebroventricularly Increases Anxiety, Depression-Like Behavior, and Anhedonia in Normal Weight Rats

Nesfatin-1 is a well-established anorexigenic peptide. Recent studies indicated an association between nesfatin-1 and anxiety/depression-like behavior. However, it is unclear whether this effect is retained in obesity. The aim was to investigate the effect of nesfatin-1_30-59—the active core of nesfatin-1—on anxiety and depression-like behavior in normal weight (NW) and diet-induced (DIO) obese rats. Male rats were intracerebroventricularly (ICV) cannulated and received nesfatin-1_30-59 (0.1, 0.3, or 0.9 nmol/rat) or vehicle 30 min before testing. Nesfatin-1_30-59 at a dose of 0.3 nmol reduced sucrose consumption in the sucrose preference test in NW rats compared to vehicle (–33%, p < 0.05), indicating depression-like/anhedonic behavior. This dose was used for all following experiments. Nesfatin-1_30-59 also reduced cookie intake during the novelty-induced hypophagia test (−62%, p < 0.05). Moreover, nesfatin-1_30-59 reduced the number of entries into the center zone in the open field test (−45%, p < 0.01) and the visits of open arms in the elevated zero maze test (−39%, p < 0.01) in NW rats indicating anxiety. Interestingly, DIO rats showed no behavioral alterations after the injection of nesfatin-1_30-59 (p > 0.05). These results indicate an implication of nesfatin-1_30-59 in the mediation of anxiety and depression-like behavior/anhedonia under normal weight conditions, while in DIO rats, a desensitization might occur.

Current Understanding of the Role of Nesfatin-1

Nesfatin-1 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.

Nesfatin-1 ameliorates testicular injury and supports gonadal function in rats induced with testis torsion

Testicular torsion causes ischemia-reperfusion injury and an increased risk of infertility. Nesfatin-1 is a novel peptide with antioxidant, anti-inflammatory and anti-apoptotic properties. In the present study, we aimed to investigate the putative beneficial effects of nesfatin-1 on oxidative injury and impaired testicular function induced by testis torsion. Under anesthesia, male Sprague-Dawley rats (180-230 g; n = 24) had sham-operation or they underwent testicular torsion by rotating the left testis 720° and fixing it for 2 h, followed by a 2-h detorsion. Rats in each group were treated intraperitoneally with either nesfatin-1 (0.3 μg/kg) or saline prior to the torsion or sham-torsion. At the end of the 4-h experimental period, tissue samples were removed for evaluation of spermatozoa, molecular and histochemical analyses. In saline-treated torsion/detorsion group, a high percentage of abnormal spermatozoa with head defects was observed, which was abolished in nesfatin-1-treated torsion/detorsion group. The levels of 8-OHdG, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, caspase-3 were increased in the saline-treated torsion/detorsion group as compared to sham-operated group, while nesfatin-1 pre-treatment significantly decreased the expressions of the pro-inflammatory cytokines, depressed apoptosis, and also reduced the tubular degeneration. In addition, nesfatin-1 in torsion/detorsion group elevated expressions of transforming growth factor (TGF)-beta and reduced expressions of protein kinase B (AKT) and cAMP response element binding protein (CREB) in the testis tissue. The present findings show that nesfatin-1, by regulating AKT and CREB signaling pathways and pro-inflammatory/anti-inflammatory cytokine balance, preserves the spermatogenic cells and ameliorates torsion-detorsion-induced tubular degeneration.