Neuropeptide W Research Articles

Neuropeptide W protects against ovarian oxidative injury and reinforces ovarian steroidogenic activity via the upregulation of ERα expression.

The aim of this study was to investigate the protective effect of neuropeptide W (NPW) on ovarian ischemia-reperfusion-induced oxidative injury and ovarian steroid metabolism. Rats were randomly divided into control and ischemia groups that received either saline or NPW (0.1 or 5 μg/kg/day). Bilateral ovarian ischemia was performed for 3 h followed by a 72-h reperfusion. Blood, ovary, and uterus samples were collected for biochemical and histological assessments. Treatment with either dose of NPW alleviated oxidative injury of the ovaries with a significant suppression in free radical formation and decreased histopathological injury in both the ovarian and uterine tissues, along with reduced lipid peroxidation and neutrophil accumulation in the uterus. Moreover, NPW treatment reversed the decrease in aromatase expression with a concomitant reduction in the expression of the inactivity enzyme estrogen sulfotransferase. Also, downregulation of estrogen receptor-α (ERα) expression in the injured ovarian tissue was abolished by NPW treatment, which implicates that the protective effect of NPW on the female reproductive system may involve the upregulation of the ERα-mediated signaling pathway. Our study demonstrated for the first time that NPW protects against ovarian oxidative injury and reinforces ovarian steroidogenic activity, which is accompanied by the upregulation of ERα expression in the ovaries.

Neuropeptide W facilitates chronic gastric ulcer healing by the regulation of cyclooxygenase and NF-κB signaling pathways

AimsPutative beneficial effects of neuropeptide W (NPW) in the early phase of gastric ulcer healing process and the involvement of cyclooxygenase (COX) enzymes were investigated in an acetic acid-induced gastric ulcer model.Main methodsIn anesthetized male Sprague–Dawley rats, acetic acid was applied surgically on the serosa and then a COX-inhibitor (COX-2-selective NS-398, COX-1-selective ketorolac, or non-selective indomethacin; 2 mg/kg/day, 3 mg/kg/day or 5 mg/kg/day; respectively) or saline was injected intraperitoneally. One h after ulcer induction, omeprazole (20 mg/kg/day), NPW (0.1 μg/kg/day) or saline was intraperitoneally administered. Injections of NPW, COX-inhibitors, omeprazole or saline were continued for the following 2 days until rats were decapitated at the end of the third day.Key findingsNPW treatment depressed gastric prostaglandin (PG) I2 level, but not PGE2 level. Similar to omeprazole, NPW treatment significantly reduced gastric and serum tumor necrosis factor-alpha and interleukin-1 beta levels and depressed the upregulation of nuclear factor kappa B (NF-κB) and COX-2 expressions due to ulcer. In parallel with the histopathological findings, treatment with NPW suppressed ulcer-induced increases in myeloperoxidase activity and malondialdehyde level and replenished glutathione level. However, the inhibitory effect of NPW on myeloperoxidase activity and NPW-induced increase in glutathione were not observed in the presence of COX-1 inhibitor ketorolac or the non-selective COX-inhibitor indomethacin.SignificanceIn conclusion, NPW facilitated the healing of gastric injury in rats via the inhibition of pro-inflammatory cytokine production, oxidative stress and neutrophil infiltration as well as the downregulation of COX-2 protein and NF-κB gene expressions.

Neuropeptide Y: an undisputed central simulator of avian appetite

During the last few decades, identifying the physiological pathways involved in appetite regulation has become popular among researchers. Although studying feeding regulation in birds, especially in poultries (for breeding purposes) and ornamental birds (for therapeutic purposes), is extremely important, limited experiments have been conducted on these animal models. Until today, more than fifty neurotransmitters affecting birds' appetite have been identified. In the current study, we overviewed the role of one of the most important neural mediators, neuropeptide Y (NPY), in regulating avian appetite. Based on the findings, the presence of this neuropeptide and its receptors in the key areas of food intake regulation, especially the arcuate nucleus (ARC) of the hypothalamus, has been proven. Numerous studies on birds have repeatedly shown the hyperphagic effects of NPY. Among the different NPY receptors, type 1, 2 and 5 receptors play the most important role in appetite regulation. It has also been observed that the interaction of NPY with neurotransmitters such as glucagon-like peptide-1 (GLP-1), vasotocin, bombesin, opioids, alpha-melanocyte-stimulating hormone (α-MSH), cocaine- and amphetamine-regulated transcript (CART) and gamma aminobutyric acid (GABA) is effective in NPY-induced hyperphagia. In addition, the NPY system is also involved in the effects of various mediators such as adiponectin, neuropeptide W (NPW), phoenixin-14, visfatin, adrenomedullin, spexin, kisspeptin, insulin, and somatostatin on appetite regulation. Finally, NPY seems to be one of the most important appetite-stimulating factors in birds and also plays an undeniable role in the effects of other neurotransmitters on appetite regulation.

The effects of neuropeptide W on food consumption and feeding behavior in neonatal meat-type chicks: Role of CRF1/CRF2 and NPY1 receptors

In several studies, the regulatory role of the neuropeptide W (NPW) system in food intake has been demonstrated. Considering the lack of avian studies in this field, the current research was conducted to evaluate the effects of intracerebroventricular (ICV) infusion of NPW and its interferences with corticotropin, melanocortin, and neuropeptide Y (NPY) receptors on meal consumption and feeding behaviors of broilers. In the first experiment, birds were injected with NPW (0.75, 1.5, and 3 nmol) in addition to saline. In the second experiment, saline, CRF1 receptor antagonist (NBI35965, 30 μg), NPW (3 nmol), and simultaneous injections of NBI35965 and NPW were performed. Experiments 3–8 were identical to experiment 2, except that CRF2 receptor antagonist (K41498, 30 μg), MC3/MC4 receptor antagonist (SHU9119, 0.5 nmol), MC4 receptor antagonist (HS024, 0.5 nmol), NPY1 receptor antagonist (BMS193885, 1.25 nmol), NPY2 receptor antagonist (CYM9484, 1.25 nmol), and NPY5 receptor (antagonist L-152,804, 1.25 nmol) were administrated instead of NBI35965. After that, cumulative feed intake and feeding behavior were monitored for 2 h and 30 min after injections, respectively. Following the infusion of NPW (1.5 and 3 nmol), there was a significant stimulation of meal consumption in chickens (P < 0.05). Concomitant injection of NBI35965 and K41498 with NPW enhanced the appetite-increasing effect of NPW (P < 0.05); while BMS193885 suppressed this effect of NPW (P < 0.05). Injection of SHU9119, HS024, CYM9484, and L-152804 with NPW at the same time, had no significant effect on NPW-induced hyperphagia (P > 0.05). NPW also significantly decreased the standing period and the number of jumps, steps, and exploratory pecks, and led to an increase in sitting period and feeding pecks (P < 0.05). Based on the observations, it seems that NPW-induced hyperphagia could be mediated through CRF1, CRF2, and NPY1 receptors in neonatal broilers.

Neuropeptide B (NPB) and NPB receptor 2b (NPBWR2b) in the ricefield eel Monopterus albus: expression and potential involvement in the regulation of gonadotropins.

The neuropeptide B/W signaling system is composed of neuropeptide B (NPB), neuropeptide W (NPW), and two cognate receptors, NPBWR1 and NPBWR2, which are involved in diverse physiological processes, including the central regulation of neuroendocrine axes in vertebrates. The components of this signaling system are not well conserved during vertebrate evolution, implicating its functional diversity. The present study characterized the ricefield eel neuropeptide B/W system, generated a specific antiserum against the neuropeptide B/W receptor, and examined the potential roles of the system in the regulation of adenohypophysial functions. The ricefield eel genome contains npba, npbb, and npbwr2b but lacks the npw, npbwr1, and npbwr2a genes. The loss of npw and npbwr1 probably occurred at the base of ray-finned fish radiation and that of npbwr2a species specifically in ray-finned fish. Npba and npbb genes are produced through whole-genome duplication (WGD) in ray-finned fish. The ricefield eel npba was expressed in the brain and some peripheral tissues, while npbb was predominantly expressed in the brain. The ricefield eel npbwr2b was also expressed in the brain and in some peripheral tissues, such as the pituitary, gonad, heart, and eye. Immunoreactive Npbwr2b was shown to be localized to Lh and Fsh cells but not to Gh or Prl cells in the pituitary of ricefield eels. Npba upregulated the expression of fshb and cga but not lhb mRNA in pituitary fragments of ricefield eels cultured in vitro. The results of the present study suggest that the NPB system of ricefield eels may be involved in the neuroendocrine regulation of reproduction.

Peripheral administration of neuropeptide W inhibits gastric emptying in rats: The role of small diameter afferent fibers and cholecystokinin receptors

Neuropeptide W (NPW), a novel hypothalamic peptide, contributes to the central regulation of food intake and energy balance, and suppresses feeding behavior when administered centrally. The aim of our study was to investigate the role of peripherally administered NPW in the modulation of gastric emptying, and to evaluate the participation of afferent fibers, cholecystokinin (CCK) receptors and gastric smooth muscle contractility in the regulatory effects of NPW on gastric motility. In Sprague-Dawley male rats equipped with gastric fistula, gastric emptying rate of the saline and peptone solutions was measured following subcutaneous administration of NPW (0.1 or 5 μg/kg) preceded by subcutaneous injections of saline, CCK-1 or CCK-2 receptor antagonists. Another group of rats with cannulas were injected subcutaneously with capsaicin for afferent denervation before commencing emptying trials. The effect of NPW on carbachol-induced gastric contractility and the role of CCK receptors in gastric smooth muscle contractility were also assessed in gastric strips. Peripheral injection of NPW delayed gastric emptying rate of both caloric and non-caloric liquid test meals, while administration of CCK-1 or CCK-2 receptor antagonists or denervation of small diameter afferents reversed NPW–induced delay in gastric emptying. Moreover, NPW inhibited antrum contractility in the organ bath. Our results revealed that peripherally administered NPW delayed liquid emptying from the stomach via the involvement of small diameter afferent neurons and CCK receptors, and thereby this regulatory role may contribute to its central regulatory role in controlling food intake and energy balance.

Central regulation of appetite in birds: Recent advances and future perspective

Understanding the mechanism of food intake is important for comprehending energy balance, obesity, and the body weight regulation. In particular, examining birds' appetite is critical for conservation efforts, managing human-bird interactions, and understanding the environmental implications of bird feeding practices. In this systematic review, using the PRISMA guideline, we investigated the mediators that were identified as factors affecting the birds' appetite in 2022 and 2023. In order to obtain the appropriate studies, suitable keywords were searched in the relevant electronic databases and an anthology of the desired articles was done. According to the findings, the central administration of adrenomedullin, apelin-13, lipopolysaccharide, neuromedins and spexin causes hypophagia in chickens, while the injection of adiponectin, neuropeptide W (NPW) and phonexin-14 increased the food intake of birds. Also, regarding the members of RF-amide peptide family, neuropeptide VF (NPVF) and neuropeptide FF (NPFF) weakened the food consumption of birds, while kisspeptin and prolactin-releasing peptide (PrRP) strengthened it. The effects observed in birds were similar to mammals in most cases, indicating the structural and general similarities in the regulatory mechanisms of these strains, on the other hand, the contradictory effects between the two species were probably caused by genetic differences. Finally, despite the progress made in identifying the factors and mechanisms involved in regulating the appetite of birds, it is recommended to conduct future studies using modern laboratory methods, especially cellular-molecular methods.

Regulation of Prepro-NeuropeptideW/B and Its Receptor in the Heart of ZDF Rats: An Animal Model of Type II DM

Neuropeptide B (NPB) and neuropeptide W (NPW) are neuropeptides, which constitute NPB/W signaling systems together with G-protein coupled receptors NPBWR1. The location and function of NPB/W signaling systems have been predominantly detected and mapped within the CNS, including their role in the modulation of inflammatory pain, neuroendocrine functions, and autonomic nervous systems. The aim of the study is to investigate the impact of diabetes on the neuropeptide B/W signaling system in different heart compartments and neurons which innervates it. In the RT-qPCR analysis, we observed the upregulation of mRNA for preproNPB in RV, for preproNPW in LA, and for NPBWR1 in DRG in diabetic rats. On the contrary, the expression of mRNA for NPBWR1 was downregulated in LV in diabetic rats. In the WB analysis, significant downregulation of NPBWR1 in LV (0.54-fold, p = 0.046) in diabetic rats was observed at the proteomic level. The presence of NPBWR1 was also confirmed in a dissected LCM section of cardiomyocytes and coronary arteries. The positive inotropic effect of NPW described on the diabetic cardiomyocytes in vitro could point to a possible therapeutic target for compensation of the contractile dysfunction in the diabetic heart. In conclusion, the NPB/W signaling system is involved in the regulation of heart functions and long-term diabetes leads to changes in the expression of individual members of this signaling system differently in each cardiac compartment, which is related to the different morphology and function of these cardiac chambers.

Evidence for progesterone acting as an inhibitor of stress axis via stimulating pituitary neuropeptide B/W receptor 2 (NPBWR2) expression in chickens

In vertebrates, the hypothalamus-pituitary-adrenal gland (HPA) axis is the main endocrine pathway regulating the stress response, thus also called the stress axis. It has been well-accepted that the stress axis is tightly controlled by both hypothalamic stimulators and inhibitors [e.g. corticotropin (ACTH)-releasing inhibitory factor (CRIF)]. However, the identity of authentic CRIF remains unclear for decades. Recently, neuropeptide W (NPW) was proved to be the physiological CRIF in chickens. Together with its functional receptor (NPBWR2), they play critical roles in attenuating the activity of the chicken stress axis. Because increasing pieces of evidence suggested that sex steroids could regulate the stress axis, using chicken as a model, we investigated whether the newly identified CRIF and its receptor are under the control of sex steroids in this study. Our results showed that: (1) expression of NPW-NPBWR2 in the hypothalamus-pituitary axis was sexually dimorphic and developmental stage-dependent; (2) progesterone (P4), rather than 17β-estradiol (E2) and dihydrotestosterone (DHT), could dose- and time-dependently upregulate NPBWR2 expression, which was accompanied with the decrease of ACTH synthesis and secretion, in cultured pituitary cells; (3) intraperitoneal injection of P4 could elevate the mRNA level of pituitary NPBWR2; (4) P4-stimulated NPBWR2 expression was relevant to both nPR-mediated genomic action and mPRs-triggered nongenomic route associated with MEK/ERK, PI3K/AKT cascade, and calcium influx. To our knowledge, our results discover a novel route of sex steroids in modulating the stress axis of chickens, which lays a foundation to reveal the complicated interaction network between reproduction and stress axes in chickens.

Evidence for Neuropeptide W Acting as a Physiological Corticotropin-releasing Inhibitory Factor in Male Chickens.

In vertebrates, adrenocorticotropin (ACTH), released by the pituitary gland, is a critical part of the stress axis and stress response. Generally, the biosynthesis and secretion of ACTH are controlled by both hypothalamic stimulatory factors and inhibitory factors [eg, ACTH-releasing inhibitory factor (CRIF)], but the identity of this CRIF remains unrevealed. We characterized the neuropeptide B (NPB)/neuropeptide W (NPW) system in chickens and found that NPW could directly target the pituitary to inhibit growth hormone (GH) and prolactin (PRL) secretion via neuropeptide B/W receptor 2 (NPBWR2), which is completely different from the mechanism in mammals. The present study first carried out a series of assays to investigate the possibility that NPW acts as a physiological CRIF in chickens. The results showed that (1) NPW could inhibit ACTH synthesis and secretion by inhibiting the 3′,5′-cyclic adenosine 5′-monophosphate/protein kinase A signaling cascade in vitro and in vivo; (2) NPBWR2 was expressed abundantly in corticotrophs (ACTH-producing cells), which are located mainly in cephalic lobe of chicken pituitary, as demonstrated by single-cell RNA-sequencing, immunofluorescent staining, and fluorescence in situ hybridization; (3) dexamethasone could stimulate pituitary NPBWR2 and hypothalamic NPW expression in chicks, which was accompanied by the decease of POMC messenger RNA levels, as revealed by in vitro and subcutaneous injection assays; and (4) the temporal expression profiles of NPW-NPBWR2 pair in hypothalamus-pituitary axis and POMC in pituitary were almost unanimous in chicken. Collectively, these findings provide comprehensive evidence for the first time that NPW is a potent physiological CRIF in chickens that plays a core role in suppressing the activity of the stress axis.

Neuropeptide W Attenuates Oxidative Multi-Organ Injury in Rats Induced with Intra-Abdominal Sepsis.

Sepsis leads to systemic hypotension, disturbed perfusion, inflammation, and tissue toxicity in vital organs. Neuropeptide W (NPW) has modulatory effects in the control of blood pressure and inflammatory processes, implicating a potential beneficial effect against sepsis-induced oxidative damage. Under anesthesia, male Sprague Dawley rats underwent cecal ligation and puncture. Immediately after surgery, either saline or TNF-alpha inhibitor (etanercept; 1 mg/kg) antibiotic (ceftriaxon; 10 mg/kg) combination or NPW (0.1, 1, or 3 μg/kg) was given subcutaneously, and injections were repeated on the 12thand 24thh. The sham-operated control group was treated with saline at the same time points. All rats were euthanized on the 25thh of surgery. Sepsis resulted in oxidative damage of the brain, heart, lung, liver, and kidney. Elevations in blood urea nitrogen and alkaline phosphatase, showing renal and hepatic dysfunction, were not evident when septic rats were treated with NPW. NPW reduced serum levels of C-reactive protein, corticosterone, and interleukin-6, while histopathologically verified tissue damage in all the studied tissues was ameliorated. NPW treatment suppressed lipid peroxidation in the heart, lung, and brain, and the depleted antioxidant GSH levels of the brain and heart were replenished by NPW. Moreover, sepsis-related neutrophil recruitment to the liver and lung was also suppressed by NPW. Although the survival rate of the rats was not significantly prolonged by NPW, most of these improvements in systemic and local inflammatory events were comparable with those reached by the etanercept and antibiotic combination, suggesting the therapeutic impact of NPW during the acute period of sepsis.

Vaspin (but not neuropeptide B or neuropeptide W) as a possible predictor of body weight normalization in anorexia nervosa.

IntroductionThe aim of the study was to evaluate the correlation between the nutritional status of patients with anorexia nervosa (AN) and levels of vaspin (VASP), neuropeptide B (NPB), neuropeptide W (NPW) and total antioxidant status (TAS).Material and methodsNinety serum samples collected from 30 teenage female patients during the acute stage of AN and 30 healthy persons (CONTR) were subjected to biochemical analysis; patients with AN were examined at the beginning of the study (AN-I) and after hospitalization (AN-II), as a result of which partial stabilization of anthropometric measurements was achieved (an increase of body mass index (BMI) by 3.5 kg/m2).ResultsVaspin levels dropped at the end of the hospitalization (compared to AN-I, p < 0.05), achieving values comparable to the CONTR; moreover there was a positive correlation between VASP level and the achieved body weight in AN-II (p < 0.05). Positive correlations were also noted with regard to VASP vs. NPB in AN-I (p < 0.02) (and AN-II, p < 0.013), as well as in the case of VASP vs. NPW in the same groups (p < 0.02 and p < 0.015, respectively). NPB concentration was higher in AN-I (p < 0.05) and AN-II (p < 0.018) than in CONTR, whereas there were no differences (p > 0.05) with regard to levels of VASP, NPW, or TAS.ConclusionsThe high level of NPB despite treatment and normalization of VASP level may suggest that there are chronic neuroendocrine disorders at play in anorexia nervosa.

The synergistic effects of opioid and neuropeptide B/W in rat acute inflammatory and neuropathic pain models

The use of morphine is controversial due to the incidence of rewarding behavior, respiratory depression, and tolerance, leading to increased drug dose requirements, advancing to morphine addiction. To overcome these barriers, strategies have been taken to combine morphine with other analgesics. Neuropeptide B23 and neuropeptide W23 (NPB23 and NPW23) are commonly used to relieve inflammatory pain and neuropathic pain. As NPB23 and NPW23 system shares similar anatomical basis with opioid system at least in the spinal cord we hypothesized that NPB23 or NPW23 and morphine may synergistically relieve inflammatory pain and neuropathic pain. To test this hypothesis, we demonstrated that μ opioid receptor and NPBW1 receptor (receptor of NPB23 and NPW23) are colocalized in the superficial dorsal horn of the spinal cord. Secondly, co-administration of morphine witheitherNPB23 or NPW23 synergistically attenuated inflammatory and neuropathic pain. Furthermore, either NPB23 or NPW23 significantly reduced morphine-induced conditioned place preference (CPP) and constipation. We also found that phosphorylation of extracellular-regulated protein kinase (ERK1/2) following morphine was profoundly potentiated by the application of NPB23 or NPW23. Hence, combination of morphine with either NPB23 or NPW23 reduced dose of morphine required for pain relief in inflammatory and neuropathic pain, while effectively prevented some side-effects of morphine.

Neuropeptide W, an endogenous NPBW1 and NPBW2 ligand, produced an analgesic effect via activation of the descending pain modulatory system during a rat formalin test.

Neuropeptide W (NPW) messenger ribonucleic acid (mRNA) and NPBW1 and/or NPBW2 mRNA are expressed in the descending pain inhibitory system. In the present study, we examined whether NPW microinjected into the descending pain inhibitory system, such as the periaqueductal gray (PAG), locus coeruleus (LC), and rostral ventromedial medulla (RVM), produces an analgesic effect using a rat formalin test. Microinjections of NPW into the PAG ipsilateral and contralateral to the formalin-injected side, LC ipsilateral and contralateral to the formalin-injected side, and RVM produced an analgesic effect. In the RVM study, the analgesic effect was antagonized by WAY100135, a 5-HT1A antagonist, and enhanced by prazosin, an α1 antagonist, and SB269970, a 5-HT7 antagonist. Naloxone, an opioid antagonist, also antagonized the effect of NPW in the RVM study. In the ipsilateral LC study, the analgesic effect was antagonized by WAY100135, idazoxan, an α2 antagonist, and naloxone and was enhanced by prazosin and SB269970. In the contralateral LC study, the analgesic effect was antagonized by prazosin, idazoxan, SB269970, and naloxone. The analgesic effect was antagonized by WAY100135, SB269970, idazoxan, and naloxone in the ipsilateral and contralateral PAG studies. These findings strongly suggest that NPBW1/W2 activation by NPW microinjection into the RVM, LC, and PAG affect the descending pain modulatory system and produce anti-nociceptive and pro-nociceptive effects in the rat formalin test.

Identification of NPB, NPW and Their Receptor in the Rat Heart.

Members of neuropeptide B/W signaling system have been predominantly detected and mapped within the CNS. In the rat, this system includes neuropeptide B (NPB), neuropeptide W (NPW) and their specific receptor NPBWR1. This signaling system has a wide spectrum of functions including a role in modulation of inflammatory pain and neuroendocrine functions. Expression of NPB, NPW and NPBWR1 in separate heart compartments, dorsal root ganglia (DRG) and stellate ganglia was proven by RT-qPCR, Western blot (WB) and immunofluorescence. Presence of mRNA for all tested genes was detected within all heart compartments and ganglia. The presence of proteins preproNPB, preproNPW and NPBWR1 was confirmed in all the chambers of heart by WB. Expression of preproNPW and preproNPB was proven in cardiac ganglionic cells obtained by laser capture microdissection. In immunofluorescence analysis, NPB immunoreactivity was detected in nerve fibers, some nerve cell bodies and smooth muscle within heart and both ganglia. NPW immunoreactivity was present in the nerve cell bodies and nerve fibers of heart ganglia. Weak nonhomogenous staining of cardiomyocytes was present within heart ventricles. NPBWR1 immunoreactivity was detected on cardiomyocytes and some nerve fibers. We confirmed the presence of NPB/W signaling system in heart, DRG and stellate ganglia by proteomic and genomic analyses.

Neuropeptide W regulates proliferation and differentiation of ATDC5: Possible involvement of GPR7 activation, PKA and PKC-dependent signalling cascades.

Various neuropeptides related to the energy equilibrium affect bone growth in humans and animals. Neuropeptides W (NPW) are identical in the internal ligands of the two G‐protein receptors (GPRs) included in subtypes 7 and 8. Neuropeptides W inhibits proliferation in the cultivated rat calvarial osteoblast‐like (ROB) cells. This study examines the expression of NPW and GPR7 in murine chondrocyte and their function. An immunohistochemical analysis showed that NPW and GPR7 were expressed in the proliferative chondrocytes of the growth plates in the hind limbs of mice. The NPW mRNA quickly elevated in the early differentiation (7‐14 days) of ATDC5 cells, while NPW and GPR7 mRNA were reduced during the late stage (14‐21 days) of differentiation. Neuropeptide W‐23 (NPW‐23) promoted the proliferation of ATDC5 cells, which was attenuated by inhibiting the GPR7, protein kinase A (PKA), protein kinase C (PKC) and ERK1/2 pathways. Neuropeptide W‐23 enhanced the early cell differentiation, as evaluated by collagen type II and the aggrecan gene expression, which was unaffected by inhibiting the ERK1/2 pathway, but significantly decreased by inhibiting the PKA, PKC and p38 MAPK pathways. In contrast, NPW‐23 was not involved in the terminal differentiation of the chondrocytes, as evaluated by the mineralization of the chondrocytes and the activity of the alkaline phosphatase. Neuropeptides W stimulated the PKA, PKC, p38 MAPK and ERK1/2 activities in a dose‐ and time‐dependent manner in the ATDC5 cells. These results show that NPW promotes the proliferation and early differentiation of murine chondrocyte via GPR7 activation, as well as PKA and PKC‐dependent signalling cascades, which may be involved in endochondral bone formation.

Distribution and Function of Neuropeptides W/B Signaling System.

Neuropeptide W (NPW) and neuropeptide B (NPB) are two structurally and functionally related regulatory peptides, which are highly expressed in several brain regions and, additionally, in some peripheral tissues. Nevertheless, their distributions in the tissues are not similar. They act on target tissues via two subtypes of G protein-coupled receptors which are designated as NPBWR1 (GPR7) and NPBWR2 (GPR8), respectively, and possess different binding affinities. NPB activates NPBWR1, whereas NPW stimulates both the receptors with similar potency. Both of these peptides takes a part in the central regulation of neuroendocrine axes, feeding behavior, energy homeostasis, cardiovascular functions, circadian rhythm, pain sensation, modulation of inflammatory pain, and emotions. Over the past few years, studies have shown that NPB is also involved in sleep regulation. On the contrary, NPW participates in regulation of vascular myogenic tone, inhibits gastric tension sensitive vagal afferents and insulin secretion. Also, expression of NPW in the stomach is regulated by feeding. Abovementioned findings clearly demonstrate the functional diversity among NPW versus NPB signaling systems. In this review, signal transduction pathways of NPW/NPB are critically evaluated and observed together with mapping of expression of their signaling systems.

Neuropeptide B and Vaspin as New Biomarkers in Anorexia Nervosa.

Introduction The aim of the study was to assess the correlation between the levels of neuropeptide B (NPB), neuropeptide W (NPW), vaspin (VAS), and the total antioxidant status (TAS) in the blood, as well as nutritional status of patients with anorexia nervosa (AN). Materials and Methods The study covered a cohort of 76 female teenagers, including 46 females with extreme AN and 30 healthy peers (CONTR) aged 12-17. Results AN persons were characterized by higher (in comparison to CONTR) NPB and VAS concentrations and lower values of TAS levels, body weight, and anthropometric values. Positive correlations between NPB and VAS levels were noted in the AN group (R=0.33; p<0.001) as well as between concentrations of NPW and VAS in the same group (R=0.49; p<0.001). Furthermore, positive correlations existed between NPB and NPW concentrations across the whole studied population (AN+CONTR; R=0.75; p<0.000001), AN (R=0.73; p<0.000001) and CONTR (R=0.90; p<0.0005). Conclusions In detailed diagnostics of AN it is worth considering testing NPB and VAS levels.

Neuropeptide B and neuropeptide W as new serum predictors of nutritional status and of clinical outcomes in pediatric patients with type 1 diabetes mellitus treated with the use of pens or insulin pumps.

IntroductionThe aim of our study was to determine the relationship between neuropeptide B (NPB), neuropeptide W (NPW), nutritional and antioxidant status and selected fat- and bone-derived factors in type 1 diabetes mellitus (T1DM) treated using pens (T1DM pen group) or insulin pumps (T1DM pump group) in order to investigate the potential role of NPB and NPW in the clinical outcomes of T1DM.Material and methodsFifty-eight patients with T1DM and twenty-five healthy controls (CONTR) participated in the study. Assessments of NPB, NPW, total antioxidant status (TAS), leptin, adiponectin, osteocalcin, and free soluble receptor activator for nuclear factor κB (free sRANKL) were conducted.ResultsNPB, NPW, leptin, and TAS were lower (by 33%, p < 0.013; 34%, p < 0.008; 290%, p < 0.00004; 21%, p < 0.05; respectively), while adiponectin was by 51% higher (p < 0.006) in T1DM vs. CONTR, while osteocalcin and free sRANKL levels were similar in both groups. NPW was lower in the T1DM pen group both vs. the T1DM pump group (36% lower, p < 0.0009) and vs. the CONTR group (35% lower, p < 0.002). In the T1DM pen group, but not in the T1DM pump group or the CONTR group, the Cole index and TAS levels explain (besides NPB) the variation in NPW values. ROC curves showed that serum levels of leptin, adiponectin, NPB and NPW (but not osteocalcin or free sRANKL) were predictive indicators for T1DM.ConclusionsMeasurements of NPB and NPW, besides leptin and adiponectin, are worth considering in the detailed prognosis of nutritional status in T1DM, primarily in the T1DM pen-treated population.

Role of brain-derived neurotrophic factor and nerve growth factor in the regulation of Neuropeptide W in vitro and in vivo

Nerve growth factor (NGF) and Brain-derived neurotrophic factor (BDNF) are neurotrophic factors involved in the growth, survival and functioning of neurons. In addition, a possible role of neurotrophins, particularly BDNF, in HPA axis hyperactivation has recently been proposed. Neuropeptide W (NPW) is an endogenous peptide ligand for the GPR7 and GPR8 and a stress mediator in the hypothalamus. It activates the HPA axis by working on hypothalamic corticotrophin-releasing hormone (CRH). No information is available about the interrelationships between neurotrophines like NGF/BDNF and NPW. We studied the effect and underlying mechanisms of NGF/BDNF on the production of NPW in PC12 cells and hypothalamus. NGF time- and concentration-dependently stimulated the expression of NPW in PC12 cells. The effect of NGF was blocked by the inhibition of PI3K/Akt signal pathway with specific inhibitors for PI3K or AktsiRNA for Akt while inhibition of ERK pathway had no effect. Moreover, BDNF concentration-dependently induced the expression of NPW mRNA and decreased the expression of NPY mRNA in primary cultured hypothalamic neurons which was also blocked by a PI3K kinase inhibitor. Finally, in vivo study showed that exogenous BDNF injected icv increased NPW production in the hypothalamus and this effect was reversed by a PI3 kinase inhibitor. These results and the fact that BDNF was able to stimulate the expression of CRH demonstrated that neurotrophines can modulate the expression of NPW in neuronal cells via the PI3K/Akt pathway and suggest that BDNF might be involved in functions of the HPA axis, at least in part by modulating the expression of NPW/NPY and CRH.