Comparison of aprepitant versus ondansetron for prevention of postoperative nausea and vomiting: A systematic review and meta-analysis with trial sequential analysis.

Background and Aims: Postoperative nausea and vomiting (PONV) is a common complication after surgery. Preventing PONV in high-risk patients often requires a multimodal approach combining antiemetic drugs with diverse mechanisms. While aprepitant, a neurokinin-1 receptor antagonist, is recognised as highly effective for PONV prevention, uncertainties remain regarding its effectiveness. Methods: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The analysis assessed the effectiveness of aprepitant (A), aprepitant plus ondansetron (AO) and aprepitant plus dexamethasone and ondansetron (ADO) in preventing PONV compared to ondansetron alone (O) or in combination with dexamethasone (DO). Results: In the analysis of 12 studies involving 2729 patients, aprepitant demonstrated significant efficacy in preventing PONV compared to ondansetron alone (A versus [vs.] O: PONV incidence 12.5% vs. 28.5%, relative risk [RR] = 0.45, P < 0.001; complete response rate 55.97% vs. 50.35%, RR = 1.13, P = 0.010). The combination of aprepitant with ondansetron (AO) also showed a significantly lower incidence of PONV compared to ondansetron alone (11.3% vs. 26.8%, RR = 0.43, P < 0.001) and a higher complete response rate (38.1% vs. 26.84%, RR = 1.41, P = 0.020). In addition, ADO significantly reduced PONV incidence compared to DO (ADO vs. DO: 13.63% vs. 35.38%, RR = 0.38, P = 0.006). Conclusion: Aprepitant, whether used alone or in combination with ondansetron or both ondansetron and dexamethasone, consistently outperforms ondansetron in achieving a complete response as it lowers vomiting rates and reduces the need for rescue therapy during the crucial 24-48-h postoperative period.

Fosaprepitant improves cyclophosphamide-induced bladder damage by alleviating inflammatory response in mice.

Inhibition of inflammatory process is a key therapeutic target for the treatment of interstitial cystitis (IC). Recent reports indicate that neurokinin 1 receptor (NK1R) antagonists have beneficial roles in inflammatory-based diseases. Herein, we investigate the protective effects of fosaprepitant (FOS), a NK1R antagonist, in cyclophosphamide (CP)-induced cystitis. The cystitis model was established multiple CP (80 mg/kg; i.p.) injection one day apart, and mice were treated with FOS (20 and 60 mg/kg/day; i.p.) for seven consecutive days. Detrusor contractility, vesical vascular permeability, myeloperoxidase (MPO) activity and protein expression levels of the TLR4 pathway were evaluated in mice bladder. Carbachol and electric field stimulation-evoked contractions of detrusor strips were significantly increased in CP-treated mice, which was significantly attenuated by FOS (60 mg/kg/day) treatment (p<0.001, p<0.05). Notably, vesical vascular permeability was markedly impaired in CP-induced cystitis, that was restored by FOS (60 mg/kg/day) treatment (p<0.01). MPO activity was significantly increased in cystitis group whereas FOS (20 and 60 mg/kg/day) treatment remarkably suppressed MPO activity in bladder tissue (p<0.001). Although TLR4 expression increased with cystitis, MyD88 and p-NFκBSer536/total NFκB did not change, FOS (20 and 60 mg/kg/day) treatment caused a dramatic decrease in TLR4 expression (p<0.001), indicating the anti-inflammatory effect of FOS. In conclusion, FOS improved detrusor overactivity and inflammatory response by inhibiting MPO activity and TLR4 expression, resulting in functional and histological recovery in CP-induced cystitis.

Electroacupuncture alleviates neuropathic pain by regulating hippocampal SP/NK1R/ARRB1 pathway. / 电针调控海马SP/NK1R/ARRB1é€šè·¯ç¼“è§£å¤§é¼ ç¥žç»ç— ç†æ€§ç–¼ç—›çš„ç ”ç©¶.

OBJECTIVES: To observe the effect of electroacupuncture (EA) on pain, anxiety like behavior, and substance P(SP) /neurokinin-1 receptor (NK1R) /ß -arrestin 1(ARRB1) pathway related protein expression in hippocampus of chronic constriction injury (CCI) rats, so as to explore its mechanisms underlying improvement of neuropathic pain. METHODS: Twenty-seven male SD rats were randomly divided into sham operation, model and EA groups, with 9 rats in each group. The CCI model was established by ligature of the left sciatic nerve. On the 8th day following modeling, EA (2 Hz, 0.5-1.5 mA) was applied to the left "Huantiao" (GB34) and "Yanglingquan" (GB34) for 30 min, once every other day for 13 times. Mechanical paw withdrawal threshold (MWT), thermal paw withdrawal threshold (TWL) and difference of the weight distribution of the hind limbs were detected before operation and at the 5th, 9th, 17th, 25th and 33rd days after operation. Open field test was used to evaluate the anxiety-like behavior of rats. The content of SP in hippocampus was determined by ELISA. The protein expression of NK1R and ARRB1 in hippocampus was detected by Western blot. RESULTS: Compared with the sham operation group, the MWT and TWL of the left hind limb at the 5th, 9th, 17th, 25th and 33rd days after operation, the time of entering the central area and the total distance of movement, and the content of SP in the hippocampus were significantly decreased (P<0.001, P<0.01), while the difference of the weight distribution of the hind limbs at the 5th, 9th, 17th, 25th and 33rd days after operation and the protein expression of NK1R and ARRB1 were significantly increased (P<0.001, P<0.05) in the model group. After EA intervention, the MWT and TWL of the left hind limb, the time of entering the central area and the total moving distance, and the expression of SP in the hippocampus were significantly increased (P<0.01, P<0.001, P<0.05), while the difference in the weight distribution of the hind limbs was significantly reduced, and the expression of NK1R and ARRB1 protein in the hippocampus were significantly decreased (P<0.001, P<0.05) in the EA group. CONCLUSIONS: EA can effectively improve the pain and anxiety behaviors in CCI rats, and reverse the abnormal expression of SP, NK1R and ARRB1 proteins in the hippocampus, which may be related to its effects in regulating the SP/NK1R/ARRB1 pathway in the hippocampus.

Comparison between Substance P and Calcitonin Gene-Related Peptide and Their Receptors in Colorectal Adenocarcinoma.

Background: Colorectal cancer is a major health problem that still causes many deaths worldwide. Neuropeptides, such as substance P and calcitonin gene-related peptide, play the neurotransmitter and neurohormone roles that increase tumor invasiveness and metastasis potential. This study aimed to see whether these neuropeptides and their receptors-neurokinin 1 receptor and calcitonin receptor-like receptor-correlate with the diagnosis stage, tumor differentiation grade, and different patient characteristics in colorectal cancer and also to compare them. Methods: We performed serum analyses of substance P and CGRP levels in patients with colorectal cancer and also the immunohistochemical analysis of their receptors in colorectal tumors and then correlated them with the disease stage and with different tumor characteristics. Results: We demonstrated that both substance P and calcitonin gene-related peptide had increased levels in colorectal cancer and that their levels correlated with the stage of the disease and with the tumor differentiation grade. We also demonstrated the correlation of NK-1R and CRLR higher immunohistochemical scores with advanced and poorly differentiated tumors. Conclusions: This study demonstrates that the neuropeptides SP and CGRP and their receptors NK-1R and CRLR could play a role in the pathogenesis of colorectal cancer, and they could be used as diagnostic and prognostic markers and could represent potential therapeutic targets.

Endomorphin-2 (Endo2) and substance P (SubP) co-application attenuates SubP-induced excitation and alters frequency plasticity in neonatal rat in vitro preparations.

Substance P (SubP) and endomorphin-2 (Endo2) are co-localized presynaptically in vesicles of neurons adjacent to inspiratory rhythm-generating pre-Botzinger Complex (preBotC) neurons but the effects of co-released SubP and Endo2 on respiratory motor control are not known. To address this question, SubP alone or a combination of SubP and Endo2 (SubP/Endo2) were bath-applied in a sustained (15-min) or intermittent (5-min application, 5-min washout, x3) pattern at 10-100 nM to neonatal rat brainstem-spinal cord preparations. During neuropeptide application, SubP/Endo2 co-applications generally attenuated SubP-induced increases in burst frequency and decreases in burst amplitude. With respect to frequency plasticity (long-lasting increase in burst frequency 60 min post-neuropeptide application), SubP-induced frequency plasticity was increased with sustained SubP/Endo2 co-applications at 20 and 100 nM. Intermittent SubP/Endo2 co-applications tended to decrease the level of frequency plasticity induced by intermittent SubP alone applications. SubP/Endo2 co-applications revealed potentially new functions for neurokinin-1 (NK1R) and mu-opioid (MOR) receptors on respiratory rhythm-generating medullary neurons.

Defining the clinical benefits of adding a neurokinin-1 receptor antagonist to control chemotherapy-induced nausea and vomiting in moderately emetogenic chemotherapy: a systematic review and meta-analysis of the clinical practice guidelines for antiemesis 2023 from the Japan society of clinical oncology.

BACKGROUND: Chemotherapy-induced nausea and vomiting (CINV) commonly affects patient quality of life and the overall effectiveness of chemotherapy. This study aimed to evaluate whether adding neurokinin-1 receptor antagonists (NK1RAs) to 5-hydroxytryptamine-3 receptor antagonists (5-HT3RAs) and corticosteroids provides clinically meaningful benefits in preventing CINV in patients receiving moderately emetogenic chemotherapy (MEC). METHODS: We conducted a systematic review of PubMed, Cochrane Library, and Ichushi-Web to identify clinical studies evaluating NK1RAs combined with 5-HT3RAs and dexamethasone for managing CINV in MEC. The endpoints were complete response (CR), complete control (CC), total control (TC), adverse events, and costs. The data were analyzed using a random effects model. RESULTS: From 142 articles identified, 15 randomized controlled trials (RCTs), involving 4,405 patients, were included in the meta-analysis. Approximately 60% of the patients received carboplatin (CBDCA)-based chemotherapy. The meta-analysis showed that triplet antiemetic prophylaxis with NK1RA was significantly more effective for achieving CR than doublet prophylaxis in each phase. Regarding CC, the triplet antiemetic prophylaxis was significantly more effective than the doublet in the overall (risk difference [RD]: 0.11, 95% confidence interval [CI]: 0.06-0.17) and delayed (RD: 0.08, 95% CI: 0.02-0.13) phases. For TC, no significant differences were observed in any phase. Adding NK1RA did not cause adverse events. CONCLUSIONS: Adding NK1RA to CBDCA-based chemotherapy has shown clinical benefits. However, the clinical benefits of NK1RA-containing regimens for overall MEC have not yet been established and require RCTs that exclusively evaluate MEC regimens other than CBDCA-based chemotherapy.

Comparative effectiveness of netupitant-palonosetron plus dexamethasone versus aprepitant-based regimens in mitigating chemotherapy-induced nausea and vomiting: a meta-analysis of randomized controlled trials.

BACKGROUND: Despite guidelines for managing chemotherapy-induced nausea and vomiting (CINV), there remains a need to clarify the optimal use of neurokinin-1 (NK1) receptor antagonists. Comparing the effectiveness of NEPA (netupitant-palonosetron) plus dexamethasone with other NK1 antagonist-based regimens combined with a 5HT3 receptor antagonist and dexamethasone is crucial for informed decision-making and improving patient outcomes. METHODS: We conducted a systematic review of the literature to assess randomized controlled trials (RCTs) comparing the efficacy, safety, and cost-effectiveness of NEPA plus dexamethasone and other NK1 antagonist-based regimens combined with a 5HT3 receptor antagonist and dexamethasone. PubMed, Embase, and the Cochrane Library databases were systematically searched, with the latest update performed in December 2023. Data on patient demographics, chemotherapy regimen characteristics, and outcomes were extracted for meta-analysis using a random-effects model. RESULTS: Seven RCTs were analyzed. NEPA plus dexamethasone showed superior efficacy in achieving complete response in the overall (risk ratio [RR], 1.15; 95% CI, 1.02--1.30) and delayed phases (RR, 1.20; 95% CI, 1.03-1.41) of chemotherapy. It was more effective in controlling nausea (overall phase RR, 1.20; 95% CI, 1.05-1.36; delayed phase RR, 1.21; 95% CI, 1.05-1.40) and reducing rescue therapy use (overall phase RR, 1.45; 95% CI, 1.07-1.95; delayed phase RR, 1.75; 95% CI, 1.10-2.78). Adverse event rates were comparable (RR, 1.03; 95% CI, 0.96-1.10). Subgroup analysis indicated NEPA's particular efficacy in patients receiving moderately emetogenic chemotherapy (RR, 1.31; 95% CI, 1.07-1.60). CONCLUSION: NEPA plus dexamethasone regimens exhibit superior efficacy in preventing CINV, supporting their preferential inclusion in prophylactic treatment protocols. Its effective symptom control, safety profile, and cost-effectiveness endorse NEPA-based regimens as a beneficial option in CINV management.

Safety assessment of neurokinin-1 receptor antagonist: real-world adverse event analysis from the FAERS database.

Background: Aprepitant, fosaprepitant, and netupitant are three common neurokinin-1 receptor antagonists (NK-1RAs) used to prevent chemotherapy-induced nausea and vomiting, following highly or moderately emetogenic chemotherapy. Understanding their different adverse event (AE) profiles may help clinicians make appropriate treatment decisions. Methods: All data collected from the FDA Adverse Event Reporting System (FAERS) database from the first quarter of 2004 to the fourth quarter of 2023 underwent disproportionality analysis to detect, evaluate, and compare AE signals of the three NK-1RAs. Results: A total of 3,904, 1,123, and 243 AE reports related to aprepitant, fosaprepitant, and netupitant, respectively, were extracted from the FAERS database. Of these, more than 50% of respondents were female, and most of them were aged 45-65 years. General disorders and administration-site conditions, and gastrointestinal disorders were the most frequent signals in the system organ class of the three NK-1RA drugs. In addition, aprepitant was strongly associated with joint deposit (ROR = 26.27) and fosaprepitant was closely related to seizure-like phenomena (ROR = 26.90); two preferred terms (PTs) were not mentioned in the manual. Statistically, netupitant was likely to induce death (N = 63, ROR = 8.78, 95% CI: 6.75-11.42). Additionally, neutropenic colitis, colitis, and stomatitis were unique to netupitant. Furthermore, the AE profiles of the three NK-1RA drugs were different by gender. Conclusion: The AE profiles for aprepitant, fosaprepitant, and netupitant were different. In addition to paying attention to common AEs, clinicians need to pay attention to new emerging AEs, such as joint deposit, seizure-like phenomena, neutropenic colitis, colitis, and stomatitis, regarding the three NK-1RA drugs. Furthermore, the AE compositions of the three NK-1RA drugs were different in different genders, and clinicians should take these factors into account when selecting NK-1RAs for CINV treatment.

Dexamethasone-sparing strategies in anthracycline and cyclophosphamide-based chemotherapy with a focus on 5-HT3 receptor antagonists: a network meta-analysis.

Background: The effectiveness of a dexamethasone-sparing strategy in the treatment of breast cancer with anthracycline-cyclophosphamide therapy when combined with first-generation 5-HT3 receptor antagonists (RAs) and neurokinin-1 RAs is unclear. This is attributable to a lack of evidence from direct comparison of multiple doses of DEX to a single dose of DEX in combination with first-generation 5-HT3 RAs in anthracycline-cyclophosphamide therapy. Our goal was to clarify the impact of dexamethasone-sparing strategies that involve both first-generation 5-HT3 RAs and palonosetron when combined with neurokinin-1 RAs, using a network meta-analysis. Materials and methods: A literature search was conducted on PubMed/Medline for articles published up to July 4, 2023. We included randomized controlled trials which assessed the efficacy of antiemetic regimens which combined 5-HT3 RAs and dexamethasone, with or without neurokinin-1 RAs, for the initial dose in anthracycline-cyclophosphamide therapy for patients with breast cancer. The primary outcome was the proportion of patients achieving a complete response during the delayed phase (CR-DP). Results: The difference in the proportion of patients achieving CR-DP between multiple and single doses of dexamethasone was 0.1% (95%CI: -12.4 to 12.5) with palonosetron and neurokinin-1 RAs, compared to 5.3% (95%CI: -13.4 to 23.0) with a single dose of a first-generation 5-HT3 receptor antagonist. Additionally, the difference was 12.7% (95% CI: -2.8 to 28.2) when comparing palonosetron against first-generation 5-HT3 RAs in combination with a single dose of dexamethasone and neurokinin-1 RAs. Conclusion: Palonosetron is recommended rather than a single dose of first-generation 5-HT3 RAs in dexamethasone-sparing strategies for anthracycline-cyclophosphamide therapy.

Unveiling the Promising Role of Substance P/Neurokinin 1 Receptor in Cancer Cell Proliferation and Cell Cycle Regulation in Human Malignancies.

Neurokinin receptors are a family of G protein-coupled receptors that were first identified in the central and peripheral nervous systems. However these receptors were later found in other types of cells, therefore, new perspectives concerning their novel roles were described. Mammalian has three neurokinin receptors, among which neurokinin-1 receptors [NK1R] have been indicated to be involved in most, if not all, intracellular functions, primarily the regulation of cell proliferation. By interacting with its potent agonist, substance P [SP], NK1R can engage a variety of signaling pathways and serve as a platform for cells to proliferate by regulating the expression of the cell cycle-related genes. Furthermore, the activity of SP/NK1R is stimulated by various oncogenes, indicating the involvement of this pathway in human cancers. As a result, numerous NK1R antagonists have been investigated in oncology trials, and the promising anti-- cancer effect of these receptors has opened up new possibilities for incorporating these antagonists into cancer treatment. Considering these factors, gaining a deeper understanding of the SP/NK1R pathway could offer significant advantages for cancer patients. The more knowledge we acquire about this pathway, the greater the potential for exploiting it in the development of effective treatment strategies. Here, we present a comprehensive review of the current knowledge pertaining to the biological function of the SP/NK1R, with a specific emphasis on its recently discovered role in the regulation of cell proliferation. Moreover, we provide insights into the impact of this pathway in human cancers, along with an overview of the most significant NK1R antagonists currently utilized in cancer research studies.

Substance P Promotes Leukocyte Infiltration in the Liver and Lungs of Mice with Sepsis: A Key Role for Adhesion Molecules on Vascular Endothelial Cells.

Substance P (SP), encoded by the Tac1 gene, has been shown to promote leukocyte infiltration and organ impairment in mice with sepsis. Neurokinin-1 receptor (NK1R) is the major receptor that mediates the detrimental impact of SP on sepsis. This investigation studied whether SP affects the expression of adhesion molecules, including intercellular cell adhesion molecule-1 (ICAM1) and vascular cell adhesion molecule-1 (VCAM1) on vascular endothelial cells in the liver and lungs, contributing to leukocyte infiltration in these tissues of mice with sepsis. Sepsis was induced by caecal ligation and puncture (CLP) surgery in mice. The actions of SP were inhibited by deleting the Tac1 gene, blocking NK1R, or combining these two methods. The activity of myeloperoxidase and the concentrations of ICAM1 and VCAM1 in the liver and lungs, as well as the expression of ICAM1 and VCAM1 on vascular endothelial cells in these tissues, were measured. The activity of myeloperoxidase and the concentration of ICAM1 and VCAM1 in the liver and lungs, as well as the expression of ICAM1 and VCAM1 on vascular endothelial cells in these tissues, increased in mice with CLP surgery-induced sepsis. Suppressing the biosynthesis of SP and its interactions with NK1R attenuated CLP surgery-induced alterations in the liver and lungs of mice. Our findings indicate that SP upregulates the expression of ICAM1 and VCAM1 on vascular endothelial cells in the liver and lungs, thereby increasing leukocyte infiltration in these tissues of mice with CLP surgery-induced sepsis by activating NK1R.

Substance P regulates memory Th17 cell generation and maintenance in chronic dry eye disease.

Substance P (SP) is a neuropeptide expressed by nerves and an array of cells that serves as a critical mediator of neuroinflammation. Our recent work has demonstrated that blocking the preferred receptor for SP, neurokinin-1 receptor (NK1R), effectively suppresses the induction of acute dry eye disease (DED) by preserving regulatory T cell (Treg) function, while inhibiting antigen-presenting cell (APC) maturation and subsequent generation of effector Th17 cells (eTh17). Clinically, DED is a chronic disorder characterized by sustained ocular surface inflammation which is mediated by long-lived memory Th17 cells (mTh17) demonstrated in our well-established chronic DED model. The present study aimed to further understand the function of SP in the chronic phase of DED and its role in regulating the underlying pathogenic mTh17. In vitro culture of effector T cells isolated from acute DED with SP led to an enhanced conversion of eTh17 to mTh17, while culturing memory T cells isolated from chronic DED with SP effectively preserved the mTh17 cells. In contrast, the addition of an NK1R antagonist in the cultures abolished the SP-mediated effects. Furthermore, in vivo treatment with the NK1R antagonist during the resolution phase of acute DED significantly suppressed mTh17 generation, and treatment in the chronic phase of DED disrupted the maintenance of mTh17. Taken together, our results demonstrate that increased expression of SP promotes mTh17 generation and maintenance in chronic DED, and thus blockade of SP represents a novel promising mTh17-targeting strategy in treating chronic ocular surface inflammation.

Neurokinin-1 Receptor Antagonism Reduces Nonallergic Ocular Redness in a Rabbit Model.

Purpose: To evaluate the therapeutic efficacy of topical application of a neurokinin-1 receptor (NK1R) antagonist in a rabbit model of nonallergic ocular redness. Methods: Nonallergic ocular redness was induced in rabbits by a single, topical application of dapiparzole hydrochloride eye drops (0.5%, 1%, 2%, or 5%). The NK1R antagonist L-703,606 was topically applied to the eye at the same time of induction or 20 min after induction, and phosphate buffered saline (PBS) treatment served as the control. Superior bulbar conjunctival images were taken every 30 s for the first 2 min, followed by every 4 min for 8 min, and then every 10 min until 1 h. The severity of ocular redness was evaluated on the images using ImageJ-based ocular redness index (ORI) calculations. Results: The ORI scores were significantly increased after the application of 0.5%, 1%, 2%, or 5% dapiparzole at each time point evaluated, with the most severe redness induced by the 5% dapiprazole that led to a maximal mean increase in ORI score of 14 at 20 min post-induction and thus used for subsequent evaluation of therapeutic efficacy of NK1R antagonism. Topical L-703,606, when applied at the same time as dapiprazole induction, significantly suppressed the increase of ORI scores at all time points (∼40% decrease). Furthermore, when applied at 20 min after dapiprazole induction, L-703,606 rapidly and effectively suppressed the increase of ORI scores at 30, 40, 50, and 60 min (∼30% decrease). Conclusions: Topical blockade of NK1R effectively prevents and alleviates nonallergic ocular redness in a novel animal model.

Anatomical distribution of µ-opioid receptors, neurokinin-1 receptors, and vesicular glutamate transporter 2 in the mouse brainstem respiratory network.

µ-Opioid receptors (MORs) are responsible for mediating both the analgesic and respiratory effects of opioid drugs. By binding to MORs in brainstem regions involved in controlling breathing, opioids produce respiratory depressive effects characterized by slow and shallow breathing, with potential cardiorespiratory arrest and death during overdose. To better understand the mechanisms underlying opioid-induced respiratory depression, thorough knowledge of the regions and cellular subpopulations that may be vulnerable to modulation by opioid drugs is needed. Using in situ hybridization, we determined the distribution and coexpression of Oprm1 (gene encoding MORs) mRNA with glutamatergic (Vglut2) and neurokinin-1 receptor (Tacr1) mRNA in medullary and pontine regions involved in breathing control and modulation. We found that >50% of cells expressed Oprm1 mRNA in the preBötzinger complex (preBötC), nucleus tractus solitarius (NTS), nucleus ambiguus (NA), postinspiratory complex (PiCo), locus coeruleus (LC), Kölliker-Fuse nucleus (KF), and the lateral and medial parabrachial nuclei (LBPN and MPBN, respectively). Among Tacr1 mRNA-expressing cells, >50% coexpressed Oprm1 mRNA in the preBötC, NTS, NA, Bötzinger complex (BötC), PiCo, LC, raphe magnus nucleus, KF, LPBN, and MPBN, whereas among Vglut2 mRNA-expressing cells, >50% coexpressed Oprm1 mRNA in the preBötC, NTS, NA, BötC, PiCo, LC, KF, LPBN, and MPBN. Taken together, our study provides a comprehensive map of the distribution and coexpression of Oprm1, Tacr1, and Vglut2 mRNA in brainstem regions that control and modulate breathing and identifies Tacr1 and Vglut2 mRNA-expressing cells as subpopulations with potential vulnerability to modulation by opioid drugs.NEW & NOTEWORTHY Opioid drugs can cause serious respiratory side-effects by binding to µ-opioid receptors (MORs) in brainstem regions that control breathing. To better understand the regions and their cellular subpopulations that may be vulnerable to modulation by opioids, we provide a comprehensive map of Oprm1 (gene encoding MORs) mRNA expression throughout brainstem regions that control and modulate breathing. Notably, we identify glutamatergic and neurokinin-1 receptor-expressing cells as potentially vulnerable to modulation by opioid drugs and worthy of further investigation using targeted approaches.

Rapid elucidation of agonist-driven regulation of the neurokinin 1 receptor using a GPCR phosphorylation immunoassay.

Agonist-induced phosphorylation is a crucial step in the activation/deactivation cycle of G protein-coupled receptors (GPCRs), but direct determination of individual phosphorylation events has remained a major challenge. We have recently developed a bead-based immunoassay for the quantitative assessment of agonist-induced GPCR phosphorylation that can be performed entirely in 96-well plates, thus eliminating the need for western blot analysis. In the present study, we adapted this assay to three novel phosphosite-specific antibodies directed against the neurokinin 1 (NK1) receptor, namely pS338/pT339-NK1, pT344/pS347-NK1, and pT356/pT357-NK1. We found that substance P (SP) stimulated concentration-dependent phosphorylation of all three sites, which could be completely blocked in the presence of the NK1 receptor antagonist aprepitant. The other two endogenous ligands of the tachykinin family, neurokinin A (NKA) and neurokinin B (NKB), were also able to induce NK1 receptor phosphorylation, but to a much lesser extent than substance P. Interestingly, substance P promoted phosphorylation of the two distal sites more efficiently than that of the proximal site. The proximal site was identified as a substrate for phosphorylation by protein kinase C. Analysis of GPCR kinase (GRK)-knockout cells revealed that phosphorylation was mediated by all four GRK isoforms to similar extents at the T344/S347 and the T356/T357 cluster. Knockout of all GRKs resulted in abolition of all phosphorylation signals highlighting the importance of these kinases in agonist-mediated receptor phosphorylation. Thus, the 7TM phosphorylation assay technology allows for rapid and detailed analyses of GPCR phosphorylation.

Suppressing the Substance P-NK1R Signalling Protects Mice against Sepsis-Associated Acute Inflammatory Injury and Ferroptosis in the Liver and Lungs.

Substance P (SP), encoded by the TAC1/Tac1 gene, acts as a significant mediator in dysregulated systemic inflammatory response and associated organ injury in sepsis by activating the neurokinin-1 receptor (NK1R). This study investigated the impact of SP-NK1R signaling on ferroptosis in the liver and lungs of mice with sepsis. Sepsis was induced by caecal ligation puncture (CLP) surgery in mice. The SP-NK1R signaling was suppressed by Tac1 gene deletion, NK1R blockade, and a combination of these two approaches. The physiological conditions of mice were recorded. The profile of the SP-NK1R cascade, inflammatory response, ferroptosis, and tissue histology were investigated in the liver and lungs. Several manifestations of sepsis occurred in Tac1+/+ mice during the development of sepsis. Notably, hypothermia became significant four hours after the induction of sepsis. In the liver and lungs of mice subjected to CLP surgery, the concentrations of SP and NK1R were upregulated. Additionally, the concentrations of pro-inflammatory mediators, including cytokines (IL-1ß, IL-6, and TNF-α) and chemokines (MCP-1 and MIP-2), were increased. Moreover, ferroptosis was elevated, as evidenced by increased concentrations of iron and MDA and reduced concentrations of GSH, Nrf2, and Gpx4. Suppressing the SP-NK1R cascade significantly mitigated CLP-surgery-induced alterations in mice. Importantly, these three approaches used to suppress SP-NK1R signaling showed similar effects on protecting mice against sepsis. In conclusion, increased SP-mediated acute inflammatory response and injury in the liver and lungs in mice with CLP-surgery-induced sepsis was associated with elevated ferroptosis. The detrimental effect of SP on sepsis was predominantly mediated by NK1R. Therefore, the suppression of increased SP-NK1R signaling and ferroptosis may be a promising adjuvant therapeutic candidate for sepsis and associated acute liver and lung injury.

Comparing the Efficacy of Fosnetupitant, an NK1 Receptor Antagonist in CDDP-Based Regimens, with That of Fosaprepitant and Aprepitant: A Retrospective Observational Study.

Existing antiemetic therapy against emetic-risk agents across malignancies 24 h post-dose in the acute period in cisplatin (CDDP)-based regimens yields a satisfactory complete response (CR) rate of ≥90%. However, the control rate after 24 h in the delayed period is unsatisfactory. This study compared the efficacy of fosnetupitant (F-NTP), a neurokinin 1 receptor antagonist, with that of fosaprepitant (F-APR) and aprepitant (APR) in the treatment of patients with cancer at high emetic risk due to chemotherapy. In this retrospective case-control study involving patients receiving cisplatin-containing regimens and neurokinin 1 receptor antagonists, patients were divided into three groups based on prophylactic antiemetic therapy: F-NTP, F-APR, and APR. The CR rate was evaluated for each period up to 168 h and further subdivided into acute (0-24 h), delayed (24-120 h), overall (0-120 h), and beyond-delayed (120-168 h) periods. Eighty-eight patients were included in the F-NTP group, 66 in the F-APR group, and 268 in the APR group. The CR rates at 0-168 and 120-168 h after cisplatin administration were significantly higher in the F-NTP group than in the F-APR and APR groups. After adjusting for confounding factors, F-NTP use was an independent factor in the multivariate analysis. Prophylactic antiemetic therapy, including F-NTP, was effective and well-tolerated during the delayed period. The efficacy of F-NTP in managing chemotherapy-induced nausea and vomiting was superior to those of F-APR and APR during the study period.

Effect of Selective 5-Hydroxytryptamine-3 Receptor and Neurokinin-1 Receptor Antagonists on Hemodynamic Changes and Arrhythmogenic Potential in Patients Receiving Chemotherapy: A Retrospective, Observational Study.

Background: Prior speculation suggests that selective 5-hydroxytryptamine-3 receptors and neurokinin-1 receptor antagonists may increase arrhythmia risk and induce electrocardiographic changes. This study examined the effect of anti-emetic medications on arrhythmogenic potential and hemodynamic alterations. Methods: We considered patients aged 18 or above receiving chemotherapy between June 2013 and December 2013. Patients were grouped by anti-emetic medication: intravenous granisetron (Group G), oral aprepitant plus IV granisetron (Group AG), IV palonosetron (Group P), and oral aprepitant plus IV palonosetron (Group AP). We recorded blood pressure and electrocardiography initially and at the thirtieth minute post-medication, focusing on P dispersion, QTc dispersion, and systolic/diastolic blood pressure alterations. Results: The study included 80 patients (20 per group). Baseline systolic/diastolic blood pressure and P dispersion showed no significant variance. However, the baseline QTc dispersion was significantly lower in Groups P and AP than G and AG. The thirtieth-minute systolic/diastolic blood pressures were significantly lower than the baseline for Groups AG and AP, and the heart rates decreased in all groups. Group P showed significantly fewer blood pressure changes. Conclusions: We found no arrhythmogenic potential linked to granisetron, palonosetron, and aprepitant. Hypotension was more frequent at 30 min post-medication in granisetron or aprepitant recipients. Considering no hypotension occurred when using palonosetron alone, this treatment was deemed safer.

Advances in the research and application of neurokinin-1 receptor antagonists. / 神经激肽1å—ä½“æ‹®æŠ—å‰‚çš„ç ”ç©¶ä¸Žåº”ç”¨è¿›å±•.

Recently, the substance P (SP)/neurokinin-1 receptor (NK-1R) system has been found to be involved in various human pathophysiological disorders including the symptoms of coronavirus disease 2019 (COVID-19). Besides, studies in the oncological field have demonstrated an intricate correlation between the upregulation of NK-1R and the activation of SP/NK-1R system with the progression of multiple carcinoma types and poor clinical prognosis. These findings indicate that the modulation of SP/NK-1R system with NK-1R antagonists can be a potential broad-spectrum antitumor strategy. This review updates the latest potential and applications of NK-1R antagonists in the treatment of human diseases and cancers, as well as the underlying mechanisms. Furthermore, the strategies to improve the bioavailability and efficacy of NK-1R antagonist drugs are summarized, such as solid dispersion systems, nanonization, and nanoencapsulation. As a radiopharmaceutical therapeutic, the NK-1R antagonist aprepitant was originally developed as radioligand receptor to target NK-1R-overexpressing tumors. However, combining NK-1R antagonists with other drugs can produce a synergistic effect, thereby enhancing the therapeutic effect, alleviating the symptoms, and improving patients quality of life in several diseases and cancers.