Molecular Aspects Involved in the Mechanisms of Bothrops jararaca Venom-Induced Hyperalgesia: Participation of NK1 Receptor and Glial Cells.

Accidents caused by Bothrops jararaca (Bj) snakes result in several local and systemic manifestations, with pain being a fundamental characteristic. The inflammatory process responsible for hyperalgesia induced by Bj venom (Bjv) has been studied; however, the specific roles played by the peripheral and central nervous systems in this phenomenon remain unclear. To clarify this, we induced hyperalgesia in rats using Bjv and collected tissues from dorsal root ganglia (DRGs) and spinal cord (SC) at 2 and 4 h post-induction. Samples were labeled for Iba-1 (macrophage and microglia), GFAP (satellite cells and astrocytes), EGR1 (neurons), and NK1 receptors. Additionally, we investigated the impact of minocycline, an inhibitor of microglia, and GR82334 antagonist on Bjv-induced hyperalgesia. Our findings reveal an increase in Iba1 in DRG at 2 h and EGR1 at 4 h. In the SC, markers for microglia, astrocytes, neurons, and NK1 receptors exhibited increased expression after 2 h, with EGR1 continuing to rise at 4 h. Minocycline and GR82334 inhibited venom-induced hyperalgesia, highlighting the crucial roles of microglia and NK1 receptors in this phenomenon. Our results suggest that the hyperalgesic effects of Bjv involve the participation of microglial and astrocytic cells, in addition to the activation of NK1 receptors.

Skin codelivery of contact sensitizers and neurokinin-1 receptor antagonists integrated in microneedle arrays suppresses allergic contact dermatitis.

BACKGROUND: Allergic contact dermatitis (CD) is a chronic inflammatory skin disease caused by type 1 biased adaptive immunity for which there is an unmet need for antigen (Ag)-specific immunotherapies. Exposure to skin sensitizers stimulates secretion of the proinflammatory neuropeptides substance P and hemokinin 1, which signal via the neurokinin-1 receptor (NK1R) to promote the innate and adaptive immune responses of CD. Accordingly, mice lacking the NK1R develop impaired CD. Nonetheless, the role and therapeutic opportunities of targeting the NK1R in CD remain to be elucidated. OBJECTIVE: We sought to develop an Ag-specific immunosuppressive approach to treat CD by skin codelivery of hapten and NK1R antagonists integrated in dissolvable microneedle arrays (MNA). METHODS: In vivo mouse models of contact hypersensitivity and ex vivo models of human skin were used to delineate the effects and mechanisms of NK1R signaling and the immunosuppressive effects of the contact sensitizer NK1R antagonist MNA in CD. RESULTS: We demonstrated in mice that CD requires NK1R signaling by substance P and hemokinin 1. Specific deletion of the NK1R in keratinocytes and dendritic cells, but not in mast cells, prevented CD. Skin codelivery of hapten or Ag MNA inhibited neuropeptide-mediated skin inflammation in mouse and human skin, promoted deletion of Ag-specific effector T cells, and increased regulatory T cells, which prevented CD onset and relapses locally and systemically in an Ag-specific manner. CONCLUSIONS: Immunoregulation by engineering localized skin neuroimmune networks can be used to treat cutaneous diseases that like CD are caused by type 1 immunity.

Neurokinin-1 receptor antagonists for postoperative nausea and vomiting: a systematic review and meta-analysis / Antagonistas do receptor da neurocinina-1 no tratamento de náusea e vômito no pós-operatório: Revisão sistemática e meta-análise

Abstract Background: Postoperative Nausea and Vomiting (PONV) is a common complication of general anesthesia. Several kinds of antiemetics, including 5-Hydroxytryptamine3 (5-HT3) receptor antagonists, and Neurokinin-1 (NK-1) receptor antagonists have been used to treat PONV. Objectives: To compare the antiemetic effect of NK-1 receptor antagonists, including fosaprepitant. Data sources: Online databases (PubMed, MEDLINE, Scopus, The Cochrane Library databases) were used. Study eligibility criteria, participants, and interventions: Randomized Controlled Trials (RCTs) performed in patients over 18 years with ASA-PS of I‒III, aimed to assess the efficacy of antiemetics including NK-1 receptor antagonists and 5-HT3 receptor antagonists, and compared the incidence of PONV were included. Study appraisal and synthesis methods: All statistical assessments were conducted by a random effect approach, and odds ratios and 95% Confidence Intervals were calculated. Results: Aprepitant 40 mg and 80 mg significantly reduced the incidence of vomiting 0‒24 hours postoperatively (Odds Ratio [OR = 0.40]; 95% Confidence Interval [95% CI 0.30‒0.54]; p < 0.001, and OR = 0.32; 95% CI 0.19‒0.56; p < 0.001). Fosaprepitant could also reduce the incidence of vomiting significantly both 0‒24 and 0‒48 hours postoperatively (OR = 0.07; 95% CI 0.02‒0.24; p < 0.001 and OR = 0.07; 95% CI 0.02‒0.23; p < 0.001). Limitations: Risk factors for PONV are not considered, RCTs using multiple antiemetics are included, RCTs for fosaprepitant is small, and some bias may be present. Conclusions and implications of key findings: Aprepitant and fosaprepitant can be effective prophylactic antiemetics for postoperative vomiting. However, more studies are required for higher-quality meta-analyses. Systematic review registration number: CRD42019120188.

Resumo Histórico: Náusea e Vômito no Pós-Operatório (NVPO) é um evento adverso frequente da anestesia geral. Várias classes de antieméticos, incluindo antagonistas do receptor 5-Hidroxitriptamina3 (5-HT3) e antagonistas do receptor da Neurocinina-1 (NK-1), têm sido utilizados para tratar a NVPO. Objetivo: Comparar o efeito antiemético dos antagonistas do receptor NK-1, incluindo o fosaprepitanto. Fontes de dados: Foram utilizadas bases de dados on-line (PubMed, MEDLINE, Scopus, The Cochrane Library). Critérios de elegibilidade do estudo, participantes e intervenções: Foram incluídos Estudos Clínicos Randomizados (ECR) realizados em pacientes acima de 18 anos classificação ASA I a III, com o objetivo de avaliar a eficácia de antieméticos que incluíssem antagonistas do receptor NK-1 e antagonistas do receptor 5-HT3, e que comparassem a incidência de NVPO. Métodos de avaliação e síntese do estudo: Todas as avaliações estatísticas foram realizadas por abordagem de efeito aleatório e foram calculadas razões de chances e Intervalos de Confiança de 95%. Resultados: As doses de 40 mg e 80 mg de aprepitanto reduziram significantemente a incidência de vômito no período de 0 a 24 horas pós-operatórias (razão de chances [OR = 0,40]; Intervalo de Confiança de 95% [95% IC] 0,30-0,54; p < 0,001 e OR = 0,32; 95% IC 0,19-0,56; p < 0,001). O fosaprepitanto pode também reduzir significantemente a incidência de vômito tanto de 0-24 horas como no período de 0-48 horas pós-operatórias (OR = 0,07; 95% IC 0,02-0,24; p < 0,001 e OR = 0,07; 95% IC 0,02-0,23; p < 0,001). Limitações: Os fatores de risco para NVPO não foram analisados, ECRs usando múltiplos antieméticos foram incluídos, ECRs para fosaprepitanto tinham amostras pequenas, podendo haver algum viés. Conclusões e implicações dos principais achados: Aprepitanto e fosaprepitanto podem ser drogas antieméticas profiláticas efetivas para vômito no pós-operatório. No entanto, são necessários mais estudos para elaboração de meta-análises de melhor qualidade. Número de registro da revisão sistemática: CRD42019120188.

[Neurokinin-1 receptor antagonists for postoperative nausea and vomiting: a systematic review and meta-analysis]. / Antagonistas do receptor da neurocinina­1 no tratamento de náusea e vômito no pós­operatório: Revisão sistemática e meta­análise.

BACKGROUND: Postoperative Nausea and Vomiting (PONV) is a common complication of general anesthesia. Several kinds of antiemetics, including 5-Hydroxytryptamine3 (5-HT3) receptor antagonists and Neurokinin-1 (NK-1) receptor antagonists, have been used to treat PONV. OBJECTIVES: To compare the antiemetic effect of NK-1 receptor antagonists, including fosaprepitant. DATA SOURCES: Online databases (PubMed, MEDLINE, Scopus, The Cochrane Library databases) were used. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS: Randomized Controlled Trials (RCTs) performed in patients over 18 years with ASA-PS of I-III, aimed to assess the efficacy of antiemetics including NK-1 receptor antagonists and 5-HT3 receptor antagonists, and compared the incidence of PONV were included. STUDY APPRAISAL AND SYNTHESIS METHODS: All statistical assessments were conducted by a random effect approach and odds ratios and 95% Confidence Intervals were calculated. RESULTS: Aprepitant 40mg and 80mg significantly reduced the incidence of vomiting 0-24hours postoperatively (Odds Ratio [OR = 0.40]; 95% Confidence Interval [95% CI 0.30-0.54]; p < 0.001, and OR = 0.32; 95% CI 0.19-0.56; p < 0.001). Fosaprepitant could also reduce the incidence of vomiting significantly both 0-24h and 0-48hours postoperatively (OR = 0.07; 95% CI 0.02-0.24; p < 0.001 and OR = 0.07; 95% CI 0.02-0.23; p < 0.001). LIMITATIONS: Risk factors for PONV are not considered, RCTs using multiple antiemetics are included, RCTs for fosaprepitant is small, and some bias may be present. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: Aprepitant and fosaprepitant can be effective prophylactic antiemetics for postoperative vomiting. However, more studies are required for higher-quality meta-analyses. SYSTEMATIC REVIEW REGISTRATION NUMBER: CRD42019120188.

The NK1 receptor antagonist NKP608 inhibits proliferation of human colorectal cancer cells via Wnt signaling pathway.

BACKGROUND: Neurokinin1 (NK1) receptor has played a vital role in the development of tumor. However, NKP608 as a NK1 receptor antagonist whether has the effect of the resistance of colorectal cancer is still unclear. Thereby, in this study, we investigated the role of NKP608 on human colorectal cancer and explored the underlying mechanism. METHODS: The cell proliferation of colorectal cancer cells was detected by cell counting kit-8 (CCK8) assay, cell migration and invasion were assessed by transwell assay, the apoptotic ratio of cells was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide stained and flow cytometry. The involvement of molecular mechanisms was examined by western blot. RESULTS: In this study, we found that NKP608 inhibited the proliferation, migration/invasion of HCT116 cells. In addition, NKP608 reduced expressions of Wnt-3a, ß-catenin, Cyclin D1, and (vascular endothelial growth factor) VEGF while induced expression of E-Cadherin. Furthermore, flow cytometry analyzed that NKP608 induced apoptosis of HCT116 cells, consistently, western blotting detecting of apoptosis-related proteins revealed that NKP608 downregulated Bcl-2 while upregulated Bax and Active-Caspase-3. CONCLUSIONS: Taken together, our results demonstrated that NKP608 inhibited colorectal cancer cell proliferation, migration and invasion via suppressing the Wnt/ß-catenin signaling pathway. Therefore, NKP608 might represent a promising therapeutic agent in the treatment of colorectal cancer.

The NK1 receptor antagonist NKP608 inhibits proliferation of human colorectal cancer cells via Wnt signaling pathway

BACKGROUND: Neurokinin1 (NK1) receptor has played a vital role in the development of tumor. However, NKP608 as a NK1 receptor antagonist whether has the effect of the resistance of colorectal cancer is still unclear. Thereby, in this study, we investigated the role of NKP608 on human colorectal cancer and explored the underlying mechanism. METHODS: The cell proliferation of colorectal cancer cells was detected by cell counting kit-8 (CCK8) assay, cell migration and invasion were assessed by transwell assay, the apoptotic ratio of cells was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide stained and flow cytometry. The involvement of molecular mechanisms was examined by western blot. RESULTS: In this study, we found that NKP608 inhibited the proliferation, migration/invasion of HCT116 cells. In addition, NKP608 reduced expressions of Wnt-3a, ß-catenin, Cyclin D1, and (vascular endothelial growth factor) VEGF while induced expression of E-Cadherin. Furthermore, flow cytometry analyzed that NKP608 induced apoptosis of HCT116 cells, consistently, western blotting detecting of apoptosis-related proteins revealed that NKP608 downregulated Bcl-2 while upregulated Bax and Active-Caspase-3. CONCLUSIONS: Taken together, our results demonstrated that NKP608 inhibited colorectal cancer cell proliferation, migration and invasion via suppressing the Wnt/ß-catenin signaling pathway. Therefore, NKP608 might represent a promising therapeutic agent in the treatment of colorectal cancer.

Peripheral substance P and neurokinin-1 receptors have a role in inflammatory and neuropathic orofacial pain models.

There is accumulating evidence that substance P released from peripheral sensory neurons participates in inflammatory and neuropathic pain. In this study it was investigated the ability of substance P to induce orofacial nociception and thermal and mechanical hyperalgesia, as well as the role of NK1 receptors on models of orofacial inflammatory and neuropathic pain. Substance P injected into the upper lip at 1, 10 and 100 µg/50 µL failed to induce nociceptive behavior. Also, substance P (0.1-10 µg/50 µL) injected into the upper lip did not evoke orofacial cold hyperalgesia and when injected at 1 µg/50 µL did not induce mechanical hyperalgesia. However, substance P at this latter dose induced orofacial heat hyperalgesia, which was reduced by the pre-treatment of rats with a non-peptide NK1 receptor antagonist (SR140333B, 3mg/kg). Systemic treatment with SR140333B (3 mg/kg) also reduced carrageenan-induced heat hyperalgesia, but did not exert any influence on carrageenan-induced cold hyperalgesia. Blockade of NK1 receptors with SR140333B also reduced by about 50% both phases of the formalin response evaluated in the orofacial region. Moreover, heat, but not cold or mechanical, hyperalgesia induced by constriction of the infraorbital nerve, a model of trigeminal neuropathic pain, was abolished by pretreatment with SR140333B. Considering that substance P was peripherally injected (i.e. upper lip) and the NK1 antagonist used lacks the ability to cross the blood-brain-barrier, our results demonstrate that the peripheral SP/NK1 system participates in the heat hyperalgesia associated with inflammation or nerve injury and in the persistent pain evoked by formalin in the orofacial region.