Expression of gastrointestinal nesfatin-1 and gastric emptying in ventromedial hypothalamic nucleus- and ventrolateral hypothalamic nucleus-lesioned rats

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 < 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 < 0.05) and suppressed 6-h cumulative food intake (p < 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 < 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.

Increased serum nesfatin-1 levels in patients with acromegaly

Nesfatin-1 was identified as a satiety factor involved in the regulation of metabolism. Altered levels of circulating nesfatin-1 had been observed in a variety of diseases characterized by energy imbalance. However, there was no published data about nesfatin-1 levels in acromegaly.We evaluated serum nesfatin-1 levels in 13 patients with acromegaly at baseline and postoperatively, and in 21 age- and body mass index (BMI)-matched healthy subjects.Compared with the healthy subjects, patients with acromegaly had significantly increased levels of serum insulin, high-density lipoprotein cholesterol, triglyceride, and growth hormone (GH). Moreover, the acromegaly group had nesfatin-1 levels higher than controls (1.96 ± 0.56 ng/mL vs 0.61 ± 0.10 ng/mL, P = .004). There was a positive correlation of serum nesfatin-1 levels with diastolic blood pressure (r = 0.579, P = .038) and homeostasis model assessment of insulin resistance (HOMA-IR) (r = 0.598, P = .031) in patients with acromegaly. While a successful surgery decreased serum GH levels, the serum nesfatin-1 levels did not change in acromegaly (P = .965). At last, we compared serum GH/nesfatin-1 levels with predictive markers for aggressive behaviors in pituitary adenomas. There was no relationship between serum nesfatin-1 levels and tumor's size, Ki-67 index, mutant p53, or MGMT proteins. However, increased serum GH levels were positively correlated with tumors' size (P = .023) and mutant p53 proteins expression (P = .028).Circulating nesfatin-1 was increased in acromegaly, which was involved in metabolism regulation.

Antioxidant, Anti-Inflammatory and Anti-Apoptotic Activities of Nesfatin-1: A Review

Nesfatin-1, a newly identified energy-regulating peptide, is widely expressed in the central and peripheral tissues, and has a variety of physiological activities. A large number of recent studies have shown that nesfatin-1 exhibits antioxidant, anti-inflammatory, and anti-apoptotic properties and is involved in the occurrence and progression of various diseases. This review summarizes current data focusing on the therapeutic effects of nesfatin-1 under different pathophysiological conditions and the mechanisms underlying its antioxidant, anti-inflammatory, and anti-apoptotic activities.

Reversal of Increase in Intestinal Permeability by Mangifera indica Seed Kernel Extract in High-Fat Diet-Induced Obese Mice

Obesity and hyper-intestinal permeability are interconnected. This study is designed to evaluate the ability of Mangifera indica seed kernel extract (MESK) in restoring the intestinal barrier and preventing obesity and associated metabolic complications in a high-fat diet-induced obese mouse model. Four groups of Swiss albino mice: (1) normal diet (ND), (2) high-fat diet (HFD), (3) HFD + Orlistat (100 µg/kg), and (4) HFD + MESK (75 µg/kg), were used to monitor various biochemical parameters associated with metabolic syndrome (glucose, total cholesterol, triglycerides) and body weight in an eight-week-long study. In vivo intestinal permeability was determined by the FITC-dextran method. Interestingly, MESK significantly reduced HFD-induced body weight gain, hepatic lipid accumulation, hepatic fibrosis, hyperglycemia, and dyslipidemia. Additionally, MESK treatment restored the expression of tight junction protein Zonula Occludens-1 (ZO-1) and Claudin-1 and hence prevented increased intestinal permeability induced by a high-fat diet. Moreover, it also increased the expression of potent satiety molecule Nesfatin-1 in the mouse jejunum. Our results, for the first time, establish MESK as a nutraceutical which prevents disruption of the intestinal barrier and thereby intercepts the adverse consequences of compromised intestinal permeability such as obesity, hyperglycemia, dyslipidemia, and systemic inflammation.

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.

Study of the effects of nesfatin-1 on gastric function in obese rats

AIM

To investigate the effects of nesfatin-1 on gastric function in obese rats.

METHODS

The obese rat model was induced by a high-fat diet. The gastric emptying rate and gastric acid secretory capacity of the rats were determined after treatment with different drug concentrations of nesfatin-1 and administration routes. Based on this, the expression of H+/K+-ATPase was measured using RT-PCR and western blot to preliminarily explore the mechanism of gastric acid secretion changes.

RESULTS

Body weight, body length, and Lee’s index of the rats significantly increased in the high-fat diet-induced obese rat model. Two hours after lateral intracerebroventricular injection of nesfatin-1, the gastric emptying rate and gastric acid secretory capacity of rats decreased. Four hours after injection, both were restored to normal levels. In addition, the expression of H+/K+-ATPase decreased and moved in line with changes in gastric acid secretory capacity. This in vivo experiment revealed that intracerebroventricular injection of nesfatin-1, rather than intravenous injection, could suppress gastric function in obese rats. Moreover, its effect on the gastric emptying and gastric acid secretory capacity of rats is dose-dependent within a certain period of time.

CONCLUSION

Through this research, we provide a theoretical basis for further studies on nesfatin-1, a potential anti-obesity drug.

The Inhibitory Effects of Nesfatin-1 in Ventromedial Hypothalamus on Gastric Function and Its Regulation by Nucleus Accumbens

Aim: The aim of this study was to investigate the effect of nesfatin-1 signaling in the ventromedial hypothalamus (VMH) on gastric functions, as well as the regulation of these effects by nucleus accumbens (NAc) projections to VMH.

Methods: The expression of c-fos in nesfatinergic VMH neurons induced by gastric distension (GD) was measured using the double fluoro-immunohistochemical staining. The firing rates of neurons were monitored with single-unit extracellular electric discharge recording. The projection of nesfatinergic neurons from NAc to VMH was observed by fluorogold retrograde tracer combined with fluoro-immunohistochemical staining. The effect of nesfatin-1 in VMH or electric stimulation in NAc on gastric function was studied by measuring food intake, gastric acid output, gastric motility, and gastric emptying, and the ability of the melanocortin-3/4 receptor antagonist SHU9119 or the anti-nesfatin-1 antibody to block nesfatin-1 in the VMH was assessed.

Results: Expression of c-fos was observed in VMH nesfatinergic neurons following GD in rats. Further, nesfatin-1 delivery to single GD-responsive neurons changed the firing rates of these neurons in the VMH. In awake, behaving rats, intra-VMH administration of nesfatin-1 inhibited food intake, gastric acid output, gastric motility, and gastric emptying. These effects were abolished by SHU9119. Fluorogold retrograde tracing showed nesfatinergic neural projection from the NAc to the VMH. Electrical stimulation of NAc modified the firing rates of the VMH neurons and inhibited food intake and gastric functions. The pretreatment with an anti-nesfatin-1 antibody in the VMH reversed the effects of NAc electrical stimulation on the VMH neuronal firing rates and gastric function.

Conclusions: Nesfatin-1 in the VMH inhibited food intake, gastric acid output, gastric motility, and gastric emptying. A nesfatinergic pathway between NAc and VMH transmitted metabolism-regulating signals.

Analyses of a satiety factor NUCB2/nesfatin-1; gene expressions and modulation by different dietary components in dogs

Nesfatin-1 is an anorexic peptide derived from a precursor, nucleobindin-2 (NUCB2), which is distributed in various organs, coexists with ghrelin in the gastric X/A-like cells and closely relates to an appetite control in rodents and humans. Nesfatin-1 may be a significant factor addressing the satiety also in veterinary medicine, however, there are few reports about nesfatin-1 in dogs. In the present study, we detected canine NUCB2/nesfatin-1 mRNA in various tissues, especially abundant in pancreas, gastrointestinal tracts, testis and cerebellum. We examined circulating nesfatin-1 concentrations and NUCB2/nesfatin-1 mRNA expressions in upper gastrointestinal tracts (gastric corpus, pyloric antrum and duodenum) in dogs fed on different types of diets. Plasma nesfatin-1 concentrations in the dogs were approximately 4 ng/ml and they did not change after feeding through the study, however, NUCB2/nesfatin-1 mRNA expressions in pyloric antrum were 1.84-fold higher in the dogs fed on a High fiber/High protein diet (P<0.001), 1.48-fold higher in the dogs fed on a High fat/Low protein diet (P<0.05) and 1.02-fold higher in the dogs fed on a Low fat/High carbohydrate diet (not significant) comparing to those on a control diet. It was concluded that High fiber/High protein and High fat/Low protein diets increased NUCB2/nesfatin-1 production in canine gastrointestinal tracts. These results may set the stage for further investigations of canine NUCB2/nesfatin-1, which may relate to satiety effects in dogs.

Nesfatin-1 - More than a food intake regulatory peptide

Nesfatin-1 was discovered a decade ago and despite the fact that it represents just one of a multitude of food intake-inhibiting factors it received increasing attention. This led to a detailed characterization of NUCB2/nesfatin-1's physiological property to reduce food intake and also gave rise to an involvement in the long term regulation of body weight, especially under conditions of obesity. In addition, studies indicated the involvement of NUCB2/nesfatin-1 in other homeostatic functions as well: glucose homeostasis, water intake, gastrointestinal functions, temperature regulation, cardiovascular functions, puberty onset and sleep. These pleiotropic actions underline the physiological relevance of this peptide. Recently, the involvement of NUCB2/nesfatin-1 in psychiatric disorders such as anxiety has been investigated giving rise to the speculation that NUCB2/nesfatin-1 represents a peptidergic link between eating and anxiety/depression disorders.