Substance P Research Articles

Insulin eye drops improve corneal wound healing in STZ-induced diabetic mice by regulating corneal inflammation and neuropeptide release

IntroductionIn recent years, insulin eye drops have attracted increasing attention from researchers and ophthalmologists. The aim of this study was to investigate the efficacy and possible mechanism of action of insulin eye drops in diabetic mice with corneal wounds.MethodsA type 1 diabetes model was induced, and a corneal epithelial injury model of 2.5 mm was established. We used corneal fluorescein staining, hematoxylin-eosin (H-E) staining and the Cochet-Bonnet esthesiometer to examine the process of wound healing. Subsequently, the expression levels of Ki-67, IL-1β, β3-tubulin and neuropeptides, including substance P (SP) and calcitonin gene-related peptide (CGRP), were examined at 72 h after corneal injury.ResultsFluorescein staining demonstrated an acceleration of the recovery of corneal epithelial injury in diabetic mice compared with the saline treatment, which was further evidenced by the overexpression of Ki-67. Moreover, 72 h of insulin application attenuated the expression of inflammatory cytokines and neutrophil infiltration. Remarkably, the results demonstrated that topical insulin treatment enhanced the density of corneal epithelial nerves, as well as neuropeptide SP and CGRP release, in the healing cornea via immunofluorescence staining.ConclusionsOur results indicated that insulin eye drops may accelerate corneal wound healing and decrease inflammatory responses in diabetic mice by promoting nerve regeneration and increasing levels of neuropeptides SP and CGRP.

Yingxiang Acupoint Embedding Improves Mucosal Barrier Function in Rats with Local Allergic Rhinitis

Introduction: Epithelial barrier disruption is the initial cause of various diseases. We previously reported that acupoint catgut embedding (AE) improves tight junction proteins (TJs) in rats with allergic rhinitis. However, whether AE improves the epithelial barrier in local allergic rhinitis (LAR) remains unknown. Methods: A total of 36 Sprague Dawley (SD) male rats aged 5–7 weeks were divided into 6 groups with 6 rats each: control group, LAR model group, false acupoint embedding + LAR group, acupoint embedding + LAR group, capsaicin + LAR group, and tunicamycin + acupoint embedding + LAR group. Behavioral observation, ELISA to detect inflammatory factors in nasal lavage fluid and serum IgE, nasal mucosal permeability test, hematoxylin-eosin staining, PCR to detect Substance P (SP), Western blot, and immunofluorescence to detect endoplasmic reticulum stress (ERS) index and TJs were used to investigate the mechanism of AE in LAR. Results: AE improved the symptoms and pathological features of nasal mucosa of LAR rats, reduced the inflammatory factors (IL4, IL5, IL13) of nasal lavage fluid, and showed no significant change in serum IgE levels in all groups. In addition, AE decreased the expression of SP in nasal mucosa of LAR rats, inhibited ERS, increased the expression of tight junction protein, reduced the permeability of nasal mucosa, and improved the function of nasal mucosal barrier. Conclusion: This study confirms that AE can improve the nasal mucosal barrier function of LAR by reducing the expression of SP, inhibiting ERS and increasing the expression of TJs, thus enhancing the nasal mucosal barrier function.

Localization of sensory nerve terminals containing calcitonin gene-related peptide (CGRP) on striated muscle fibers in the rat esophagus: Evidence for triple innervation via motor endplates

BackgroundMany esophageal striated muscles of mammals are dually innervated by the vagal and enteric nerves. Recently, substance P (SP)-sensory nerve terminals with calcitonin gene-related peptide (CGRP) were found on a few striated muscle fibers in the rat esophagus, implying that these muscle fibers are triply innervated. In this study, we examined the localization and origin of CGRP-nerve endings in striated muscles to consider their possible roles in the esophagus regarding triple innervation. MethodsWholemounts of the rat esophagus were immunolabeled to detect CGRP-nerve endings in striated muscles. Also, retrograde tracing was performed by injecting Fast Blue (FB) into the esophagus, and cryostat sections of the medulla oblongata, nodose ganglion (NG), and the tenth thoracic (T10) dorsal root ganglion (DRG) were immunostained to identify the origin of the CGRP-nerve endings. ResultsCGRP-fine, varicose nerve endings were localized in motor endplates on a few esophageal striated muscle fibers (4 %), most of which received nitric oxide (NO) synthase nerve terminals, and most of the CGRP nerve endings were SP- and transient receptor potential vanilloid member 1 (TRPV1)-positive. Retrograde tracing showed many FB-labeled CGRP-neurons positive for SP and TRPV1 in the NG and T10 DGR. ConclusionsThis study suggests that the CGRP-varicose nerve endings containing SP and TRPV1 in motor endplates are sensory, and a few esophageal striated muscle fibers are triply innervated. The nerve endings may detect acetylcholine-derived acetic acid from the vagal motor nerve endings and NO from esophageal intrinsic nerve terminals in the motor endplates to regulate esophageal motility.

Integrated Skin Metabolomics and Network Pharmacology to Explore the Mechanisms of Goupi Plaster for Treating Knee Osteoarthritis

Background and AimGoupi Plaster (GP) is topical traditional Chinese medicine preparation. It has been used to treat Knee Osteoarthritis (KOA) in clinical practice of traditional Chinese medicine (TCM). However, the mechanisms of GP relieve KOA are poorly understood. Experimental procedureRabbit models of KOA were established and treated with GP. Knee cartilage pathology was analyzed using hematoxylin and eosin staining, while plasma levels of inflammatory factors (interleukin (IL)-4, IL-6, and IL-17) and skin neurotransmitters (calcitonin gene-related peptide (CGRP), substance P (SP), and5-hydroxytryptamine (5-HT)) were measured by enzyme linked immunosorbent assay. Metabolomics based on GC-TOF-MS analysis screened for skin biomarkers as well as relevant pathways. Network pharmacology screened for relevant skin targets as well as relevant pathways, and finally, MetScape software was utilized to integrate the results of metabolomics and network pharmacology to screen for key skin targets, key metabolites, and key pathways for GP treatment of KOA. Results and ConclusionGP administration substantially repaired cartilage surface breaks in KOA and led to relatively intact cartilage structure and normal cell morphology. GP decreased plasma levels of IL-6 and IL-17 and skin levels of CGRP, SP and 5-HT while increased plasma IL-4. GP administration normalized the levels of 15 metabolites which were changed in KOA. Network pharmacology analysis identified 181 targets. Finally, 3 key targets, 5 key metabolites and 3 related pathways were identified, which suggested that GP improved skin barrier function and skin permeability by regulating skin lipid metabolism. GP treatment also regulated skin amino acid levels and subsequently affected neurotransmitters and signaling molecules. In addition, the purinergic signaling pathway was also involved in the treatment of GP against KOA.In conclusion, GP treatment is associated with changes in skin lipid metabolism, neurotransmitters, and the purinergic signaling pathway.

Alpha Calcitonin Gene-related Peptide, Neuropeptide Y, and Substance P as Biomarkers for Diagnosis and Disease Activity and Severity in Multiple Sclerosis.

Alpha calcitonin gene-related peptide (aCGRP), neuropeptide Y (NPY), and substance P (SP) are neuropeptides that have emerged recently as potent immunomodulatory factors with potential as novel biomarkers and therapeutic targets in multiple sclerosis (MS). The study aimed to detect serum levels of aCGRP, NPY, and SP in MS patients versus healthy controls and their association with disease activity and severity. Serum levels were measured in MS patients and age and sex-matched healthy controls using ELISA. We included 67 MS patients: 61 relapsing-remitting MS (RR-MS) and 6 progressive MS (PR-MS), and 67 healthy controls. Serum NPY level was found to be lower in MS patients than in healthy controls (p < 0.001). Serum aCGRP level was higher in PR-MS compared to RR-MS (p = 0.007) and healthy controls (p = 0.001), and it positively correlated with EDSS (r = 0.270, p = 0.028). Serum NPY level was significantly higher in RR-MS and PR-MS than in healthy controls (p < 0.001 and p = 0.001, respectively), and it was lower in patients with mild or moderate/severe disease than in healthy controls (p < 0.001). Significant inverse correlations were found between SP level and MS disease duration (r = -0.279, p = 0.022) and duration of current DMT (r = -0.315, p = 0.042). Lower serum levels of NPY were revealed in MS patients compared to healthy controls. Since serum levels of aCGRP are significantly associated with disease activity and severity, it is a potential disease progression marker.

Reactive Oxygen Species Induced Upregulation of TRPV1 in Dorsal Root Ganglia Results in Low Back Pain in Rats.

Dorsal root ganglia (DRGs) contain sensory neurons that innervate intervertebral discs (IVDs) and may play a critical role in mediating low-back pain (LBP), but the potential pathophysiological mechanism needs to be clarified. A discogenic LBP model in rats was established by penetration of a lumbar IVD. The severity of LBP was evaluated through behavioral analysis, and the gene and protein expression levels of pro-algesic peptide substance P (SP) and calcitonin gene-related peptide (CGRP) in DRGs were quantified. The level of reactive oxygen species (ROS) in bilateral lumbar DRGs was also quantified using dihydroethidium staining. Subsequently, hydrogen peroxide solution or N-acetyl-L-cysteine was injected into DRGs to evaluate the change in LBP, and gene and protein expression levels of transient receptor potential vanilloid-1 (TRPV1) in DRGs were analyzed. Finally, an inhibitor or activator of TRPV1 was injected into DRGs to observe the change in LBP. The rats had remarkable LBP after disc puncture, manifesting as mechanical and cold allodynia and increased expression of the pro-algesic peptides SP and CGRP in DRGs. Furthermore, there was significant overexpression of ROS in bilateral lumbar DRGs, while manipulation of the level of ROS in DRGs attenuated or aggravated LBP in rats. In addition, excessive ROS in DRGs stimulated upregulation of TRPV1 in DRGs. Finally, activation or inhibition of TRPV1 in DRGs resulted in a significant increase or decrease of discogenic LBP, respectively, suggesting that ROS-induced TRPV1 has a strong correlation with discogenic LBP. Increased ROS in DRGs play a primary pathological role in puncture-induced discogenic LBP, and excessive ROS-induced upregulation of TRPV1 in DRGs may be the underlying pathophysiological mechanism to cause nerve sensitization and discogenic LBP. Therapeutic targeting of ROS or TRPV1 in DRGs may provide a promising method for the treatment of discogenic LBP.

Analgesic and anti-inflammatory effects of galangin: a potential pathway to inhibit transient receptor potential vanilloid 1 receptor activation.

Galangin, commonly employed in traditional Chinese medicine for its diverse medicinal properties, exhibits potential in treating inflammatory pain. Nevertheless, its mechanism of action remains unclear. Mice were randomly divided into 4 groups for 7 days: a normal control group, a galangin-treated (25 and 50 mg/kg), and a positive control celecoxib (20 mg/kg). Analgesic and anti-inflammatory effects were evaluated using a hot plate test, acetic acid-induced writhing test, acetic acid-induced vascular permeability test, formalininduced paw licking test, and carrageenan-induced paw swelling test. The interplay between galangin, transient receptor potential vanilloid 1 (TRPV1), NF-κB, COX-2, and TNF-α proteins was evaluated via molecular docking. COX- 2, PGE2, IL-1β, IL-6, and TNF-α levels in serum were measured using ELISA after capsaicin administration (200 nmol/L). TRPV1 expression in the dorsal root ganglion was analyzed by Western blot. The quantities of substance P (SP) and calcitonin gene-related peptide (CGRP) were assessed using qPCR. Galangin reduced hot plate-induced licking latency, acetic acid-induced contortions, carrageenantriggered foot inflammation, and capillary permeability in mice. It exhibited favorable affinity towards TRPV1, NF- κB, COX-2, and TNF-α, resulting in decreased levels of COX-2, PGE2, IL-1β, IL-6, and TNF-α in serum following capsaicin stimulation. Galangin effectively suppressed the upregulation of TRPV1 protein and associated receptor neuropeptides CGRP and SP mRNA, while concurrently inhibiting the expression of NF-κB, TNF-α, COX-2, and PGE2 mRNA. Galangin exerts its anti-inflammatory pain effects by inhibiting TRPV1 activation and regulating COX-2, NF-κB/TNF-α expression, providing evidence for the use of galangin in the management of inflammatory pain.

NK1 tachykinin receptor antagonist treatment reduces cerebral edema and intracranial pressure in an ovine model of ischemic stroke.

Following ischemic stroke, substance P (SP)-mediated neurogenic inflammation is associated with profound blood-brain barrier (BBB) dysfunction, cerebral edema, and elevated intracranial pressure (ICP). SP elicits its effects by binding the neurokinin 1 tachykinin receptor (NK1-R), with administration of an NK1-R antagonist shown to ameliorate BBB dysfunction and cerebral edema in rodent and permanent ovine stroke models. Given the importance of reperfusion in clinical stroke, this study examined the efficacy of NK1-R antagonist treatment in reducing cerebral edema and ICP in an ovine model of transient middle cerebral artery occlusion (tMCAo). Anesthetized sheep (n = 24) were subject to 2-hours tMCAo and randomized (n = 6/group) to receive early NK1-R treatment (days 1-3 post-stroke), delayed NK1-R treatment (day 5 post-stroke), or saline vehicle. At 6-days post-stroke animals were re-anaesthetized and ICP measured, followed by MRI to evaluate infarction, edema and BBB dysfunction. Following both early and delayed NK1-R antagonist administration, ICP was significantly reduced on day 6 compared to vehicle animals (p < 0.05), accompanied by a reduction in cerebral edema, midline shift and BBB dysfunction (p < 0.05). This study demonstrates that NK1-R antagonist treatment is an effective novel therapy for cerebral edema and elevated ICP following stroke in an ovine model, warranting future clinical evaluation.

Substance P promotes TGF-β-induced collagen synthesis in human corneal fibroblasts.

Corneal fibroblasts maintain homeostasis of the corneal stroma by mediating the synthesis and degradation of extracellular collagen, and these actions are promoted by transforming growth factor-β (TGF-β) and interleukin-1b (IL-1β), respectively. The cornea is densely innervated with sensory nerve fibers that are not only responsible for sensation but also required for physiological processes such as tear secretion and wound healing. Loss or dysfunction of corneal nerves thus impairs corneal epithelial wound healing and can lead to neurotrophic keratopathy. The sensory neurotransmitter substance P (SP) promotes corneal epithelial wound healing by enhancing the stimulatory effects of growth factors and fibronectin. We have now investigated the role of SP in collagen metabolism mediated by human corneal fibroblasts in culture. Whereas SP alone had no effect on collagen synthesis or degradation by these cells, it promoted the stimulatory effect of TGF-β on collagen type I synthesis without affecting that of IL-1β on the expression of matrix metalloproteinase-1. This effect of SP on TGF-β-induced collagen synthesis was accompanied by activation of p38 mitogen-activated protein kinase (MAPK) signaling and was attenuated by pharmacological inhibition of p38 or of the neurokinin-1 receptor. Our results thus implicate SP as a modulator of TGF-β-induced collagen type I synthesis by human corneal fibroblasts, and they suggest that loss of this function may contribute to the development of neurotrophic keratopathy.

Abstract 5893: Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma

Abstract In recent years, a growing body of research has illuminated the integral role of the nervous system in the initiation and progression of cancer, giving rise to the establishment of an emergent field known as cancer neuroscience. Pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, manifests as a highly malignant solid tumor characterized by insidious onset, strong invasiveness, and a notable propensity for recurrence or metastasis. Consequently, the 5-year survival rate for PDAC remained dismally low at approximately 10% in 2021. Notably, PDAC is distinguished by perineural invasion (PNI), a phenomenon linked to postoperative recurrence and metastasis. A thorough exploration of the interplay between peripheral innervation and PDAC holds promise for identifying novel targets and therapies to enhance outcomes in PDAC. This study unveils a correlation between PDAC patients exhibiting high calcitonin gene-related peptide-positive (CGRP+) sensory innervation in the tumor microenvironment (TME) and diminished overall survival (OS) and disease-free survival (DFS) compared to those with lower CGRP+ nociceptive innervation. Concurrently, heightened CGRP+ sensory innervation corresponds to increased cancer pain, as assessed by Visual Analog Scale (VAS) scores. Further analysis reveals a negative association between CGRP+ nociceptive nerves and lymphatic metastasis, as well as tumor size in PDAC patients. In a murine PDAC model, the genetic or chemical ablation of CGRP+ sensory neurons significantly impedes disease progression. Additionally, sensory neuron ablation attenuates cancer-induced vesical pain and enhances the locomotor function of mice, suggesting an improvement in overall quality of life. Mechanically, within the TME of PDAC, the secretion of neuropeptides substance P (SP) and CGRP from sensory neurons is elevated, with CGRP exhibiting a more pronounced increase. Furthermore, the expression of the CGRP receptor—receptor activity modifying protein 1 (RAMP1)—surpasses that of the SP receptor in the TME. Subsequent blockade of the CGRP pathway using the RAMP1 antagonist Rimegepant significantly suppresses PDAC progression and alleviates cancer pain, accompanied by improved locomotor function. In summary, sensory innervation actively participates in the progression of PDAC through the secretion of CGRP. Consequently, the inhibition of the CGRP pathway emerges as a potential therapeutic strategy for both PDAC and cancer-induced pain. Citation Format: Kaiyuan Wang, Bo Ni, Xiuchao Wang, Jihui Hao. Crosstalk between sensory innervation and pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5893.

Effect of Zusanli Acupoint Injection with Anisodamine on Postoperative Recovery Quality of Patients Undergoing Bariatric Surgery.

To evaluate the influence of anisodamine injection at the Zusanli (ST36) on early postoperative recovery quality in patients who have undergone laparoscopic sleeve gastrectomy. 141 patients undergoing laparoscopic sleeve gastrectomy were randomly divided into the control group (group C), the normal saline group (group S) and the anisodamine group (group A). Acupuncture point injections were administered after induction of general anesthesia. The quality of recovery-40 questionnaire (QoR-40) scores were documented preoperatively (D0) and on the 1st (D1), 3rd (D3) and 7th (D7) days postoperatively. Additional metrics included: the numerical rating scale (NRS) for pain, postoperative nausea and vomiting (PONV), assessment and analgesic consumption 24-h post-extubation and the initial postoperative times for ambulation and anal exhaust. Substance P (SP), β-endorphin (β-EP), motilin (MTL) and gastrin (GAS) were quantified at 24-h post-surgery. Compared with group C, group A demonstrated an elevation in QoR-40 scores and physical comfort dimensions during D1-3, and an increased pain scores during D1-7; group S exhibited an augmentation in QoR-40 scores and pain scores on D1 (p < 0.05). Compared with group S, group A improved QoR-40 scores on D1 and pain scores during D1-3 (p < 0.05). SP, β-EP, MTL and GAS presented significant variances among the groups 24-h post-surgery (p < 0.05). There were significant differences between the groups in NRS pain scores and PONV scores at 24-h postoperatively, dosage of dizocin on the first postoperative day, and time to first anal defecation (p < 0.05). The administration of anisodamine via ST36 acupoint injections has been demonstrated to facilitate the recuperation of gastrointestinal functionality, to alleviate postoperative pain and nausea, and substantially to enhance the quality of early postoperative recovery.

Immunohistochemical properties of motoneurons supplying the porcine trapezius muscle.

The trapezius muscle (TRAP) belongs to the scapulothoracic group of muscles, which play a crucial role in the integrity and strength of the upper limb, trunk, head, and neck movements and, thus, in maintaining balance. Combined retrograde tracing (using fluorescent tracer Fast Blue, FB) and double-labelling immunohistochemistry were applied to investigate the chemical coding of motoneurons projecting to the porcine TRAP. FB-positive (FB+) motoneurons supplying the cervical (c-TRAP) and thoracic part (th-TRAP) of the right (injected with the tracer) TRAP were located within the IX-th Rexed lamina in the ipsilateral ventral horn of the grey matter of the spinal medulla. Immunohistochemistry revealed that nearly all the neurons were cholinergic in nature [choline acetyltransferase (CHAT)- or vesicular acetylcholine transporter (VACHT)-positive]. Many retrogradelly labelled neurons displayed also immunoreactivity to calcitonin gene-related peptide (CGRP; approximately 68% of FB+ neurons). The smaller number of nerve cells (5%, 3%, 2% or 1%, respectively) stained for nitric oxide synthase (n-NOS), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and substance P (SP). The retrogradely labelled neurons were closely apposed by nerve fibres expressing immunoreactivity to CHAT, VACHT, CGRP, SP, DβH, VIP, n-NOS, NPY, GAL, Leu-Enk and Met-Enk. Taking into account the clinical relevance of TRAP, the present results may be useful in designing further research aimed at the management of various dysfunctions of the muscle.

Huanglian-banxia promotes gastric motility of diabetic rats by modulating brain-gut neurotransmitters through MAPK signaling pathway.

Gastric motility disorder is an increasingly common problem among people with diabetes. Neurotransmitters have been recognized as critical regulators in the process of gastric motility. Previous study has shown that herb pair huanglian-banxia (HL-BX) can improve gastric motility, but the underlying mechanism is still unclear. The aim of this study was to further investigate the role of HL-BX in modulating brain-gut neurotransmission to promote gastric motility in diabetic rats, and to explore its possible mechanism. The diabetic rats were divided into five groups. Gastric emptying rate, intestinal propulsion rate, body weight, and average food intake were determined. Substance P (SP), 5- hydroxytryptamine (5-HT), and glucagon-like peptide -1 (GLP-1) in the serum were measured by enzyme-linked immunosorbent assay. Dopamine (DA) and norepinephrine (NE) in the brain were analyzed by high-pressure liquid chromatography with a fluorescence detector. Protein expression of the tissues in the stomach and brain was determined by Western blot. HL-BX reduced average food intake significantly, increased body weight, and improved gastric emptying rate and intestinal propulsion rate. HL-BX administration caused a significant increase in SP, GLP-1, and 5-HT, but a significant decrease in DA and NE. Interestingly, HL-BX regulated simultaneously the different expressions of MAPK and its downstream p70S6K/S6 signaling pathway in the stomach and brain. Moreover, berberine exhibited a similar effect to HL-BX. These results indicated that HL-BX promoted gastric motility by regulating brain-gut neurotransmitters through the MAPK signaling pathway. HL-BX and MAPK provide a potential therapeutic option for the treatment of gastroparesis.

Modification of Mesenchymal Stem/Stromal Cell-Derived Small Extracellular Vesicles by Calcitonin Gene Related Peptide (CGRP) Antagonist: Potential Implications for Inflammation and Pain Reversal.

During the progression of knee osteoarthritis (OA), the synovium and infrapatellar fat pad (IFP) can serve as source for Substance P (SP) and calcitonin gene-related peptide (CGRP), two important pain-transmitting, immune, and inflammation modulating neuropeptides. Our previous studies showed that infrapatellar fat pad-derived mesenchymal stem/stromal cells (MSC) acquire a potent immunomodulatory phenotype and actively degrade Substance P via CD10 both in vitro and in vivo. On this basis, our hypothesis is that CD10-bound IFP-MSC sEVs can be engineered to target CGRP while retaining their anti-inflammatory phenotype. Herein, human IFP-MSC cultures were transduced with an adeno-associated virus (AAV) vector carrying a GFP-labelled gene for a CGRP antagonist peptide (aCGRP). The GFP positive aCGRP IFP-MSC were isolated and their sEVs' miRNA and protein cargos were assessed using multiplex methods. Our results showed that purified aCGRP IFP-MSC cultures yielded sEVs with cargo of 147 distinct MSC-related miRNAs. Reactome analysis of miRNAs detected in these sEVs revealed strong involvement in the regulation of target genes involved in pathways that control pain, inflammation and cartilage homeostasis. Protein array of the sEVs cargo demonstrated high presence of key immunomodulatory and reparative proteins. Stimulated macrophages exposed to aCGRP IFP-MSC sEVs demonstrated a switch towards an alternate M2 status. Also, stimulated cortical neurons exposed to aCGRP IFP-MSC sEVs modulate their molecular pain signaling profile. Collectively, our data suggest that yielded sEVs can putatively target CGRP in vivo, while containing potent anti-inflammatory and analgesic cargo, suggesting the promise for novel sEVs-based therapeutic approaches to diseases such as OA.

Maropitant in veterinary medicine

The objective of this study is to review the literature on the use of maropitant citrate, a specific NK-1 antagonist that inhibits Substance P (SP), which is responsible for sensitizing new nociceptors and the main mediator in the signaling responsible for emesis, therefore originally developed for the treatment of vomiting. However, several studies have shown that Maropitant has great potential as a visceral analgesic after surgery, with the use of the drug individually or in association with another opioid. The research was carried out electronically through platforms such as Google Scholar and Scielo, among others, with the criterion of dogs and cats submitted to ovariohysterectomy (OVH) receiving Maropitant Citrate intravenously (IV) through bolus followed by continuous infusion. It was concluded through the selected studies that the use of maropitant citrate in bolus and continuous infusion, whether or not associated with other drugs, has the potential to promote trans- and postoperative analgesia and anti-inflammatory effects in animals submitted to OVH, reducing the doses of analgesic rescue.

Bergapten inhibits airway inflammation and MRGPRX2-mediated mast cells activation by targeting NR4A1

Asthma is a serious global health problem affecting 300 million persons around the world. Mast cells (MCs) play a major role in airway hyperresponsiveness (AHR) and inflammation in asthma, their exact effector mechanisms remain unclear. Here, we aim to investigate the inhibitory effect of Bergapten (BER) on MRGPRX2-mediated MCs activation through asthma model.Mouse model of asthma was established to examine the anti-asthmatic effects of BER. Calcium (Ca2+) influx, β-hexosaminidase and histamine release were used to assess MCs degranulation in vitro. RNA-Seq technique was conducted to study the gene expression profile. RT-PCR and Western Blotting were performed to examine targeting molecules expression. BER inhibited AHR, inflammation, mucous secretion, collagen deposition and lung MCs activation in asthma model. BER dramatically reduced levels of IL4, IL-5, and IL-13 in bronchoalveolar lavage fluid (BALF), as well as inflammatory cells. BER also reduced serum IgE levels. Pretreatment MCs with BER inhibited substance P (SP)-induced Ca2+ influx, degranulation and cytokines release from MCs. BER also reduced the phosphorylation levels of PKC, PLC, IP3R, AKT and ERK, which were induced by SP. Furthermore, RNA-seq analysis showed that SP up-regulated 68 genes in MCs, while were reversed by BER. Among these 68 genes, SP up-regulated NR4A1 expression, and this effect was inhibited by BER. Meanwhile, knockdown of NR4A1 significantly attenuated SP-induced MCs degranulation. In conclusion, NR4A1 plays a major role in MRGPRX2-mediated MCs activation, BER inhibited AHR and inflammation in asthmatic model by inhibiting MCs activation through MRGPRX2-NR4A1 pathway.

Rizatriptan benzoate-loaded dissolving microneedle patch for management of acute migraine therapy.

In this study, dissolving microneedles (MNs) using polyvinyl alcohol (PVA) and poly (1-vinylpyrrolidone-co-vinyl acetate) (P(VP-co-VA)) as matrix materials were developed for transdermal delivery of rizatriptan benzoate (RB) for acute migraine treatment. In-vitro permeation studies were conducted to assess the feasibility of the as-fabricated dissolving MNs to release RB. Drug skin penetration were tested by Franz diffusion cells, showing an increase of the transdermal flux compared to passive diffusion due to the as-fabricated dissolving MNs having a sufficient mechanical strength to penetrate the skin and form microchannels. The pharmacological study in vivo showed that RB-loaded dissolving MNs significantly alleviated migraine-related response by up-regulating the level of 5-hydroxytryptamine (5-HT) and down-regulating the levels of calcitonin gene-related peptide (CGRP) and substance P (SP). In conclusion, the RB-loaded dissolving MNs have advantages of safety, convenience, and high efficacy over conventional administrations, laying a foundation for the transdermal drug delivery system treatment for acute migraine.

Effect of high-frequency repetitive transcranial magnetic stimulation on swallowing function and pneumonia in poststroke dysphagia in rats

BackgroundPost-stroke dysphagia (PSD) is a common symptom of stroke. Clinical complications of PSD include malnutrition and pneumonia. Clinical studies have shown that high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) can improve the swallowing function in stroke patients. However, few studies have elucidated the underlying molecular mechanisms. MethodsA PSD rat model was established using transient middle cerebral artery occlusion (tMCAO). Rats were randomly divided into sham-operated groups, PSD groups, PSD + sham-rTMS groups, PSD + 5 Hz-rTMS groups, PSD + 10 Hz-rTMS groups and PSD + 20 Hz-rTMS groups. Rats were weighed and videofluoroscopic swallowing studies were conducted. Pulmonary inflammation, levels of substance P (SP) and calcitonin gene-related peptide (CGRP) in the serum, lung, and nucleus tractus solitarius (NTS), brain-derived neurotrophic factor (BDNF) and 5-hydroxytryptamine (5HT) in NTS were evaluated. ResultsRats in the PSD group experienced weight loss, reduced bolus area and pharyngeal bolus speed, and increased pharyngeal transit time (PTT) and inter-swallow interval (ISI) on day 7 and day 14 after operation. Moreover, PSD rats showed pulmonary inflammation, reduced levels of SP in the lung and serum, increased levels of CGRP in the lung and NTS, reduced levels of BDNF and 5HT in the NTS. There was no significant difference between the PSD group and the PSD + sham-rTMS group in the results of weight and VFSS. Comparing with the PSD group, there significant increases in the bolus area, decreases in PTT of rats following 5 Hz rTMS intervention. HF-rTMS at 10 Hz significantly increased the weight, bolus area, pharyngeal bolus speed and decreased the PTT and ISI of rats. There were also significant increases in the bolus area (p < 0.01) and pharyngeal bolus speed, decreases in PTT and ISI of rats following 20 Hz rTMS intervention. Furthermore, compared with the PSD + 5 Hz-rTMS group, there were significant increases in the bolus area and pharyngeal bolus speed, decreases in ISI in the swallowing function of rats in the PSD + 10 Hz-rTMS group. Besides, compared with the PSD + 5 Hz-rTMS group, there were significant decreases in ISI in the swallowing function of rats in the PSD + 20 Hz-rTMS group. HF-rTMS at 10 Hz alleviated pulmonary inflammation, increased the levels of SP in the lung, serum, and NTS, CGRP in the serum and NTS, 5HT in the NTS of PSD rats. ConclusionCompared with 5 Hz and 20 Hz rTMS, 10 Hz rTMS more effectively improved the swallowing function of rats with PSD. HF-rTMS at 10 Hz improved the swallowing function and alleviated pneumonia in PSD rats. The mechanism may be related to increased levels of SP in the lung, serum and NTS, levels of CGRP in the serum and NTS, 5HT in the NTS after HF-rTMS treatment.

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-1β, 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.

Excimer light effect on neurogenic inflammation in active versus stable psoriasis lesions

Neurogenic inflammation, mediated by T helper 17 cell (Th17) and neurons that release neuropeptides such as substance P (SP), is thought to play a role in the pathogenesis of psoriasis. Excimer light is used in the treatment of psoriasis via induction of T cell apoptosis. The objective of this study is to study the effect of excimer light on active versus stable psoriasis and investigate the levels of substance P and its receptor in both groups. The study included 27 stable and 27 active psoriatic patients as well as 10 matched healthy controls. Clinical examination (in the form of local psoriasis severity index (PSI) and visual analogue scale (VAS)) was done to determine disease severity, level of itching, and quality of life. Tissue levels of SP and neurokinin-1 receptor (NK-1R) were measured by ELISA before and after 9 excimer light sessions in 43 patients. A statistically significant lower levels of PSI and VAS were reached after therapy with no significant difference between the stable and active groups. The mean tissue levels of SP before therapy were significantly higher than the control group. Lower levels of SP and NK-1 receptor were found after treatment overall and in each group. Excimer therapy can be effective for both stable and active plaque psoriasis and this effect could be partly through its role on ameliorating the neurogenic inflammation.