The neuropeptide S receptor (NPSR) is a G protein‐coupled receptor that has been implicated in various disease states, such as anxiety and post‐traumatic stress disorder, and has shown promise as a target for the treatment of anxiety. Central brain administration of Neuropeptide S (NPS) in mice produces anxiolytic‐like effects, hyperlocomotion, and memory enhancement. Since current anxiety drugs cause undesirable side effects, development of more efficacious drugs is important. However, research into this system has been conducted solely in male rodents, despite females showing a higher prevalence for anxiety disorders. The current study investigated whether NPS‐mediated behavioral phenotypes seen in males translate to females, and whether they are affected by estrous cycle stage. Female C57BL/6 mice were intracerebroventricularly (ICV) cannulated and underwent various behavioral paradigms. Estrous cycle stage was determined through examination of vaginal cytology. Consistent with findings in male mice, NPS‐treated females displayed hyperlocomotion. Additionally, NPS‐treated females displayed anxiolytic‐like behaviors, but preliminary data suggests this effect is contingent on different phases of the estrous cycle. These results indicate that the NPSR could be a viable pharmaceutical target to treat anxiety disorders, as the anxiolytic phenotype is present in both sexes. However, in females, these effects seem to be dependent on the stage of the estrous cycle.

Anxiety and post‐traumatic stress have increasingly become more prominent disorders and options for treatment remain limited. One of the most prescribed therapeutics are benzodiazepines. Unfortunately, these anxiolytics have negative side effects and are not as effective in the long term. The recently discovered Neuropeptide S (NPS) system may lead to an alternative, potentially improved, line of therapeutics. This system consists of a known endogenous neuropeptide, Neuropeptide S and a G‐protein‐coupled receptor termed the Neuropeptide S receptor (NPSR). Activation of this receptor leads to an increase in intracellular calcium and a mobilization of cAMP. This is associated with behavioral phenotypes such as anxiolysis, enhanced memory consolidation, and hyperlocomotion. The NPSR is highly expressed in the amygdala linking the NPS system with fear and anxiety. Previously, as part of our ongoing drug discovery program, a biased agonist (RTI‐263) was identified that preferentially enhances the calcium signaling pathway over the cAMP pathway following NPSR binding. This biased agonist also reduced hyperlocomotion or arousal observed with NPS, while maintaining the anxiolytic component. In the present study we test another compound (RTI‐567) using classic anxiolytic, locomotor, and memory testing paradigms such as the light dark box, open field, and inhibitory avoidance. Our overall goal is to identify novel synthetic agonists with reduced side effects and improved long‐term efficacy.

Glial cell line‐derived neurotrophic factor (GDNF) has been shown to be a promising therapeutic molecule for treating Parkinson’s disease (PD). However, because of the failure of GDNF infusion in clinical trials, due to its poor bio‐distribution, there was a need to develop other molecules with similar properties to GDNF that have improved bioavailability and administration. Dopamine neuron stimulating peptide‐11 (DNSP‐11) is a synthetic, amidated 11‐amino acid neuroactive peptide derived from the human proGDNF domain. DNSP‐11 has been shown to protect dopaminergic cells in vitro and restore dopaminergic activity in vivo. Therefore, the objective of our study was to test if DNSP‐11 protects human dopaminergic neuroblastoma SH‐SY5Y cells against 6‐OHDA induced toxicity and to elucidate the protective mechanism of action. DNSP‐11 reduced the 6‐OHDA–induced increase in caspase‐3/7 activity in SH‐SY5Y cells at early time points, indicating possible protection against apoptosis. DNSP‐11 also activated the cell survival signaling pathways, ERK1, 2, and 5 in SH‐SY5Y cells. In addition, a single injection of DNSP‐11 in adult rat striatum leads to modulation of these ERK proteins in the substantia nigra. Overall, the results indicate that DNSP‐11 protects human dopaminergic neuroblastoma cells against apoptotic cell death and activates neuroprotective ERK signaling pathways, suggesting its potential therapeutic role in Parkinson’s disease (PD).

Neuropeptide S (NPS) is a neuropeptide primarily produced within three brainstem regions including locus coeruleus, trigeminal nerve nucleus, and lateral parabrachial nucleus. NPS is involved in the central regulation of stress, fear, and cognitive integration. NPS is a mediator of behavior, seeking food, and the proliferation of new adipocytes in the setting of obesity. So far, current research of NPS is only limited to animal models; data regarding its functions in humans is still scarce. Animal studies showed that anxiety and appetite might be suppressed by the action of NPS. The discovery of this neuromodulator peptide is effective considering its strong anxiolytic action, which has the potential to be an interesting therapeutic option in treating neuropsychiatric disorders. In this article, we aimed to analyze the pharmaceutical properties of NPS as well as its influence on several neurophysiological aspects—modulation of behavior, association with obesity, as well as its potential application in rehabilitation and treatment of psychiatric disorders.

Parkinson’s disease (PD) refers to one of the eminently grievous, preponderant, tortuous nerve-cell-devastating ailments that markedly impacts the dopaminergic (DArgic) nerve cells of the midbrain region, namely the substantia nigra pars compacta (SN-PC). Even though the exact etiopathology of the ailment is yet indefinite, the existing corroborations have suggested that aging, genetic predisposition, and environmental toxins tremendously influence the PD advancement. Additionally, pathophysiological mechanisms entailed in PD advancement encompass the clumping of α-synuclein inside the lewy bodies (LBs) and lewy neurites, oxidative stress, apoptosis, neuronal-inflammation, and abnormalities in the operation of mitochondria, autophagy lysosomal pathway (ALP), and ubiquitin–proteasome system (UPS). The ongoing therapeutic approaches can merely mitigate the PD-associated manifestations, but until now, no therapeutic candidate has been depicted to fully arrest the disease advancement. Neuropeptides (NPs) are little, protein-comprehending additional messenger substances that are typically produced and liberated by nerve cells within the entire nervous system. Numerous NPs, for instance, substance P (SP), ghrelin, neuropeptide Y (NPY), neurotensin, pituitary adenylate cyclase-activating polypeptide (PACAP), nesfatin-1, and somatostatin, have been displayed to exhibit consequential neuroprotection in both in vivo and in vitro PD models via suppressing apoptosis, cytotoxicity, oxidative stress, inflammation, autophagy, neuronal toxicity, microglia stimulation, attenuating disease-associated manifestations, and stimulating chondriosomal bioenergetics. The current scrutiny is an effort to illuminate the neuroprotective action of NPs in various PD-experiencing models. The authors carried out a methodical inspection of the published work procured through reputable online portals like PubMed, MEDLINE, EMBASE, and Frontier, by employing specific keywords in the subject of our article. Additionally, the manuscript concentrates on representing the pathways concerned in bringing neuroprotective action of NPs in PD. In sum, NPs exert substantial neuroprotection through regulating paramount pathways indulged in PD advancement, and consequently, might be a newfangled and eloquent perspective in PD therapy.

L-DOPA administration is the primary treatment for Parkinson’s disease (PD) but long-term administration is usually accompanied by hyperkinetic side-effects called L-DOPA-induced dyskinesia (LID). Signaling neuropeptides of the basal ganglia are affected in LID and changes in the expression of neuropeptide precursors have been described, but the final products formed from these precursors have not been well defined and regionally mapped. We therefore used mass spectrometry imaging to visualize and quantify neuropeptides in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine exposed parkinsonian and LID Macaca mulatta brain samples. We found that dyskinesia severity correlated with the levels of some abnormally processed peptides — notably, des-tyrosine dynorphins, substance P (1-7), and substance P (1-9) — in multiple brain regions. Levels of the active neuropeptides; dynorphin B, dynorphin A (1-8), α-neoendorphin, substance P (1-11), and neurokinin A, in the globus pallidus and substantia nigra correlated with putaminal levels of L-DOPA. Our results demonstrate that the abundance of selected active neuropeptides is associated with L-DOPA concentrations in the putamen, emphasizing their sensitivity to L-DOPA. Additionally, levels of truncated neuropeptides (which generally exhibit reduced or altered receptor affinity) correlate with dyskinesia severity, particularly for peptides associated with the direct pathway (i.e., dynorphins and tachykinins). The increases in tone of the tachykinin, enkephalin, and dynorphin neuropeptides in LID result in abnormal processing of neuropeptides with different biological activity and may constitute a functional compensatory mechanism for balancing the increased L-DOPA levels across the whole basal ganglia.

Yucca contains high a content of saponin that has a glucocorticord-like effect in animals, e.g., anti-inflammation and anti-microbiota. The objective of the present study was to test the hypothesis that dietary supplementation of yucca powder may alleviate heat stress and improve growth performance of growing broilers subjected to cycling high ambient temperature. A total of 240 male broiler chicks (yellow feathered chicken) aged 28 days, with body weight (BW) of 792 ± 43.7 g, were randomly allocated to one of four treatments (6 replicates per treatment): control (normal temperature, 24 ± 2°C, 24 h), fed diets supplemented with 100 mg/kg yucca under normal temperature (Y), high ambient temperature exposure (HT, 34 ± 2°C, 11 h), fed diets supplemented with 100 mg/kg yucca (HT+Y) under high ambient temperature. After 7 days of adaption, the experiment was conducted for 4 weeks (aged 28–56 days). HT significantly reduced feed intake, BW, and average daily gain (ADG) of broiler, but yucca improved the feed intake under HT condition. Yucca supplementation reduced (P < 0.05) the HT-induced increase in temperature of rectum and leg skin. Supplementation of yucca increased the hypothalamic mRNA expression of TRPV2, TRPV4, and TRPM8 (P < 0.05). Yucca reduced (P < 0.05) the plasma lipid oxidation product malondialdehyde (MDA), but did not affect the activities of antioxidant enzyme superoxide oxidase (SOD) and glutathione peroxidase (Gpx). Yucca did not affect the plasma neuro peptide Y (NPY), which was reduced by HT, yucca reduced circulation cholecystokinin (CCK) and hypothalamic mRNA expression of CCK. Supplementation of yucca increased the mRNA expression of both heat and cool sensing receptors. The results of the present study indicate that yucca could improve antioxidant status and attenuate the heat stress response by regulating hypothalamic temperature-sensing genes in growing chickens. Besides, yucca supplementation improved feed intake probably through modulating CCK in growing broilers under high ambient temperature.

Neuropeptides (NPs), a unique class of neuronal signaling molecules, participate in a variety of physiological processes and diseases. Quantitative measurements of NPs provide valuable information regarding how these molecules are differentially regulated in a multitude of neurological, metabolic, and mental disorders. Mass spectrometry (MS) has evolved to become a powerful technique for measuring trace levels of NPs in complex biological tissues and individual cells using both targeted and exploratory approaches. There are inherent challenges to measuring NPs, including their wide endogenous concentration range, transport and postmortem degradation, complex sample matrices, and statistical processing of MS data required for accurate NP quantitation. This review highlights techniques developed to address these challenges and presents an overview of quantitative MS-based measurement approaches for NPs, including the incorporation of separation methods for high-throughput analysis, MS imaging for spatial measurements, and methods for NP quantitation in single neurons.

A short framework-III (mini-M-2) conotoxin from the venom of a vermivorous species, Conus archon, inhibits human neuronal nicotinic acetylcholine receptors

Neuropeptide S and its receptor NPSR enhance the susceptibility of hosts to pseudorabies virus infection

Neuropeptide Y (NPY) is a biologically active neuropeptide that is responsible for a large list of physiological processes. We propose a short modified fragment of NPY that should at least partially have a spectrum of biological activity of the original peptide. The compound was named nonapeptide NP9. The aim of our study was to investigate the ability of the modified fragment of NPY to influence spatial memory and learning. Materials and methods: the study was performed on 24 one-year-old random-bred female rats weight 220–250 g. The animals were divided into 3 groups of 8 rats each: treated with a solvent (0.9 % NaCl), a solution of peptide NP9 0.02 mg/kg and the drug “Semax” 0.1 mg/kg. All drugs were administered intranasally. The study of the effect of the peptide NP9 on spatial memory and learning ability was performed in the psychopharmacological test the Morris water maze. Navigation parameters were analyzed using Noldus EthoVision XT 14 video tracking software. The escape latency, the distance moved, the average velocity and the meander were recorded. An inter-quadrant analysis of rat behavior was also performed, for which the frequency of appearance and time spent in certain quadrants were recorded. Results: nonapeptide NP9 in the Morris water maze test demonstrated the ability to accelerate the time to find a hidden platform, reduce the distance traveled, meander, and optimize the search strategy. Conclusions: NP9 peptide has demonstrated the ability to positively influence learning and spatial memory. The improvement in cognitive performance of animals administered with the peptide NP9 was no less than that of the reference nootropic drug Semax. These results substantiate the feasibility of further research with the aim of pharmaceutical development of a new nootropic drug

The blood-brain barrier (BBB) prevents the majority of drugs from crossing into the brain and reaching neurons. To overcome this challenge, safe and non-invasive technologies targeting receptor-mediated pathways have been developed. In this study, three single-domain antibodies (sdAbs; IGF1R3, IGF1R4, and IGF1R5) targeting the extracellular domain of the human insulin-like growth factor-1 receptor (IGF1R), generated by llama immunization, showed enhanced transmigration across the rat BBB model (SV-ARBEC) in vitro. The rate of brain uptake of these sdAbs fused to mouse Fc (sdAb-mFc) in vivo was estimated using the fluorescent in situ brain perfusion (ISBP) technique followed by optical brain imaging and distribution volume evaluation. Compared to the brains perfused with the negative control A20.1-mFc, the brains perfused with anti-IGF1R sdAbs showed a significant increase of the total fluorescence intensity (~2-fold, p<.01) and the distribution volume (~4-fold, p<.01). The concentration curve for IGF1R4-mFc demonstrated a linear accumulation plateauing at approximately 400µg (~1µM), suggesting a saturable mechanism of transport. Capillary depletion and mass spectrometry analyses of brain parenchyma post-ISBP confirmed the IGF1R4-mFc brain uptake with ~25% of the total amount being accumulated in the parenchymal fraction in contrast to undetectable levels of A20.1-mFc after a 5-min perfusion protocol. Systemic administration of IGF1R4-mFc fused with the non-BBB crossing analgesic peptide galanin (2 and 5mg/kg) induced a dose-dependent suppression of thermal hyperalgesia in the Hargreaves pain model. In conclusion, novel anti-IGF1R sdAbs showed receptor-mediated brain uptake with pharmacologically effective parenchymal delivery of non-permeable neuroactive peptides.

Neuropeptides, functioningas peptide neurotransmitters and hormones,are generated from proneuropeptide precursors by proteolytic processingat dibasic residue sites (i.e., KR, RK, KK, RR). The cysteine proteasescathepsin L and cathepsin V, combined with the serine proteases proproteinconvertases 1 and 2 (PC1/3 and PC2), participate in proneuropeptideprocessing to generate active neuropeptides. To compare the dibasiccleavage properties of these proteases, this study conducted global,unbiased substrate profiling of these processing proteases using adiverse peptide library in multiplex substrate profiling by mass spectrometry(MSP-MS) assays. MSP-MS utilizes a library of 228 14-mer peptidesdesigned to contain all possible protease cleavage sites, includingthe dibasic residue sites of KR, RK, KK, and RR. The comprehensiveMSP-MS analyses demonstrated that cathepsin L and cathepsin V cleaveat the N-terminal side and between the dibasic residues (e.g., ↓K↓R,↓R↓K, and K↓K), with a preference for hydrophobicresidues at the P2 position of the cleavage site. In contrast, theserine proteases PC1/3 and PC2 displayed cleavage at the C-terminalside of dibasic residues of a few peptide substrates. Further analyseswith a series of dipeptide-AMC and tripeptide-AMC substrates containingvariant dibasic sites with hydrophobic P2 residues indicated the preferencesof cathepsin L and cathepsin V to cleave between dibasic residue siteswith preferences for flanking hydrophobic residues at the P2 positionconsisting of Leu, Trp, Phe, and Tyr. Such hydrophobic amino acidsreside in numerous proneuropeptides such as pro-NPY and proenkephalinthat are known to be processed by cathepsin L. Notably, cathepsinL displayed the highest specific activity that was 10-, 64-, and 1268-foldgreater than cathepsin V, PC1/3, and PC2, respectively. Peptide-AMCsubstrates with dibasic residues confirmed that PC1/3 and P2 cleavedalmost exclusively at the C-terminal side of dibasic residues. Thesedata demonstrate distinct dibasic cleavage site properties and a broadrange of proteolytic activities of cathepsin L and cathepsin V, comparedto PC1/3 and PC2, which participate in producing neuropeptides forcell–cell communication.

Neuropeptide S (NPS), which is a peptide that is involved in the regulation of the stress response, seems to be relevant to the mechanism of action of antidepressants that have anxiolytic properties. However, to date, there have been no reports regarding the effect of long-term treatment with escitalopram or venlafaxine on the NPS system under stress conditions. This study aimed to investigate the effects of the above-mentioned antidepressants on the NPS system in adult male Wistar rats that were exposed to neonatal maternal separation (MS). Animals were exposed to MS for 360 min. on postnatal days (PNDs) 2-15. MS causes long-lasting behavioral, endocrine and neurochemical consequences that mimic anxiety- and depression-related features. MS and non-stressed rats were given escitalopram or venlafaxine (10mg/kg) IP from PND 69 to 89. The NPS system was analyzed in the brainstem, hypothalamus, amygdala and anterior olfactory nucleus using quantitative RT-PCR and immunohistochemical methods. The NPS system was vulnerable to MS in the brainstem and amygdala. In the brainstem, escitalopram down-regulated NPS and NPS mRNA in the MS rats and induced a tendency to reduce the number of NPS-positive cells in the peri-locus coeruleus. In the MS rats, venlafaxine insignificantly decreased the NPSR mRNA levels in the amygdala and a number of NPSR cells in the basolateral amygdala, and increased the NPS mRNA levels in the hypothalamus. Our data show that the studied antidepressants affect the NPS system differently and preliminarily suggest that the NPS system might partially mediate the pharmacological effects that are induced by these drugs.

The influence of early-life and adulthood stressors on brain neuropeptide-S system

Neuropeptide S (NPS) acts by activating its cognate receptor (NPSR). High level expression of NPSR in the posterior medial amygdala suggests that NPS-NPSR system should be involved in regulation of social behaviors induced by social pheromones. The present study was undertaken to investigate the effects of central administration of NPS or with NPSR antagonist on the alarm pheromone (AP)-evoked defensive and risk assessment behaviors in mice. Furthermore, H129-H8, a novel high-brightness anterograde multiple trans-synaptic virus, c-Fos and NPSR immunostaining were employed to reveal the involved neurocircuits and targets of NPS action. The mice exposed to AP displayed an enhancement in defensive and risk assessment behaviors. NPS (0.1–1 nmol) intracerebroventricular (i.c.v.) injection significantly attenuated the AP-evoked defensive and risk assessment behaviors. NPSR antagonist [D-Val5]NPS at the dose of 40 nmol completely blocked the effect of 0.5 nmol of NPS which showed the best effective among dose range. The H129-H8-labeled neurons were observed in the bilateral posterodorsal medial amygdala (MePD) and posteroventral medial amygdala (MePV) 72 h after the virus injection into the unilateral olfactory bulb (OB), suggesting that the MePD and MePV receive olfactory information inputs from the OB. The percentage of H129-H8-labeled neurons that also express NPSR were 90.27 ± 3.56% and 91.67 ± 2.46% in the MePD and MePV, respectively. NPS (0.5 nmol, i.c.v.) remarkably increased the number of Fos immunoreactive (-ir) neurons in the MePD and MePV, and the majority of NPS-induced Fos-ir neurons also expressed NPSR. The behavior characteristic of NPS or with [D-Val5]NPS can be better replicated in MePD/MePV local injection within lower dose. The present findings demonstrated that NPS, via selective activation of the neurons bearing NPSR in the posterior medial amygdala, attenuates the AP-evoked defensive and risk assessment behaviors in mice.

The present study proposes to investigate the effect of neuropeptide–S (NPS) on cognitive functions and depression-like behavior of MPTP-induced experimental model of Parkinson’s disease (PD). Three-month-old C57BL/6 mice were randomly divided into three groups as; Control, Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and MPTP + NPS 0.1 nmol (received intraperitoneal injection of MPTP and intracerebroventricular injection of NPS, 0.1 nmol for seven days). The radial arm maze and pole tests were carried out, and the levels of tyrosine hydroxylase (TH) were determined using western blotting. A mass spectrometer was used to measure the levels of dopamine, glutamic acid, and glutamine. The T-turn and time to descend enhanced in MPTP group, while these parameters were decreased by NPS treatment. In the MPTP group, the number of working memory errors (WME) and reference memory errors (RME) increased, whereas NPS administration decreased both parameters. Sucrose preference decreased in the MPTP group while increasing in the NPS group. MPTP injection significantly reduced dopamine, glutamic acid, and glutamine levels. NPS treatment restored the MPTP-induced reduction in glutamine and glutamic acid levels. NPS may be involved in the future treatment of cognitive impairments and depression-like behaviors in PD.

Antagonist G-targeted liposomes for improved delivery of anticancer drugs in small cell lung carcinoma

PcActx peptide, identified from the transcriptome of zoantharian Palythoa caribaeorum, was clustered into the phylogeny of analgesic polypeptides from sea anemone Heteractis crispa (known as APHC peptides). APHC peptides were considered as inhibitors of transient receptor potential cation channel subfamily V member 1 (TRPV1). TRPV1 is a calcium-permeable channel expressed in epileptic brain areas, serving as a potential target for preventing epileptic seizures. Through in silico and in vitro analysis, PcActx peptide was shown to be a potential TRPV1 channel blocker. In vivo studies showed that the linear and oxidized PcActx peptides caused concentration-dependent increases in mortality of zebrafish larvae. However, monotreatment with PcActx peptides below the maximum tolerated doses (MTD) did not affect locomotor behavior. Moreover, PcActx peptides (both linear and oxidized forms) could effectively reverse pentylenetetrazol (PTZ)-induced seizure-related behavior in zebrafish larvae and prevent overexpression of c-fos and npas4a at the mRNA level. The excessive production of ROS induced by PTZ was markedly attenuated by both linear and oxidized PcActx peptides. It was also verified that the oxidized PcActx peptide was more effective than the linear one. In particular, oxidized PcActx peptide notably modulated the mRNA expression of genes involved in calcium signaling and γ-aminobutyric acid (GABA)ergic-glutamatergic signaling, including calb1, calb2, gabra1, grm1, gria1b, grin2b, gat1, slc1a2b, gad1b, and glsa. Taken together, PcActx peptide, as a novel neuroactive peptide, exhibits prominent anti-epileptic activity, probably through modulating calcium signaling and GABAergic-glutamatergic signaling, and is a promising candidate for epilepsy management.

A neuropeptidergic circuit gates selective escape behavior of Drosophila larvae