CRTH2 Research Articles

Immune Biomarkers in Blood from Sarcoma Patients: A Pilot Study.

The main role of the host immune system is to identify and eliminate cancer cells, which is a complex process, but it is not a fail-safe mechanism. Many sarcoma patients succumb to this disease despite treatments rendered. The aim of this pilot study was to compare the levels of CD4+ T-cells, T-regulatory (Treg) cells, and cytokines such as tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin-17A (IL-17A), and transforming growth factor-beta-1 (TGF-β1) in peripheral blood leukocytes of sarcoma patients and healthy controls. For gene expression studies, total ribonucleic acid (RNA) was extracted from peripheral blood leukocytes and genes that were differentially regulated in peripheral blood leukocytes of sarcoma patients compared with healthy controls were determined using a commercial T-helper cell differentiation quantitative polymerase chain reaction (qPCR) array. Flow cytometer analysis was performed on blood samples from 26 sarcoma patients and 10 healthy controls to identify the levels of CD4+ T-cells and T-reg cells. The level of cytokines in plasma and culture supernatant were quantified using commercial enzyme-linked immunosorbent assay (ELISA) kits. A marked reduction in the percentage of CD4+ T-cells (p = 0.037) and levels of TNF-α (p = 0.004) and IFN-γ (0.010) was observed in sarcoma patients. Gene expression analysis showed five genes (homeobox A10 (HOXA10), GATA binding protein 3 (GATA3), prostaglandin D2 receptor 2 (PTGDR2), thymocyte selection associated high mobility group box (TOX), and C-C motif chemokine receptor 3 (CCR3)) were dysregulated (p < 0.05) in sarcoma patients. This study suggests that T-helper-1 immune responses are reduced in sarcoma patients.

Correction to: DP1 (Prostaglandin D2 Receptor 1) Activation Protects Against Vascular Remodeling and Vascular Smooth Muscle Cell Transition to Myofibroblasts in Angiotensin II-Induced Hypertension in Mice.

Correction to: DP1 (Prostaglandin D2 Receptor 1) Activation Protects Against Vascular Remodeling and Vascular Smooth Muscle Cell Transition to Myofibroblasts in Angiotensin II-Induced Hypertension in Mice.

Identification of 8-gene risk prediction signature associated with NOTCH1 in stomach adenocarcinoma based on bioinformatics analysis.

BackgroundStomach adenocarcinoma (STAD), is the most common histological type of gastric cancer (GC) with high mortality and poor prognosis. We sought to investigate the contribution of Notch receptor 1 (NOTCH1) to STAD immunity.MethodsThe profiles of immune cells in STAD cohorts were compared, and a correlation analysis between the NOTCH1 gene and tumor immune cell infiltration was then conducted. The immune-related genes (IRGs) associated with the NOTCH1 gene were identified. Based on the NOTCH1-associated IRGs, multiple-gene risk prediction signatures were established. The relationship between the expression levels of the selected IRGs and overall survival (OS) was analyzed by a univariate analysis. The risk score was calculated using the formula of β1x1 + β2x2 +... + βixi. A prognostic nomogram was constructed to predict individuals’ survival probabilities.ResultsIn STAD, NOTCH1 expression levels were significantly negatively associated with tumor-infiltrating lymphocyte (TIL) Act dendritic cells (DCs) (r=−0.196, P value =6.24e-05), TIL cluster of differentiation (CD) 56 bright cells (r=−0.115, P value =0.0193), TIL immature DCs (r=−0.293, P value =1.16e-09), TIL monocyte cells (r=−0.185, P value =0.000149), TIL central memory T CD4 cells (r=−0.126, P value =0.0103), and TIL gamma delta T cells (r=−0.149, P value =0.00229). The resulting risk scores of the 8-gene risk prediction signature (corticotrophin releasing hormone receptor 2 (CRHR2) (HR =1.858, P value =0.048), fms related receptor tyrosine kinase 1 (FLT1) (HR =1.268, P value =0.048), fms related receptor tyrosine kinase 4 (FLT4) (HR =1.334, P value =0.031), glial fibrillary acidic protein (GFAP) (HR =2.739, P value =0.008), platelet-derived growth factor receptor beta (PDGFRB) (HR =1.192, P value =0.02), prostaglandin D2 receptor (PTGDR) (HR =1.564, P value =0.049), semaphorin 5B (SEMA5B) (HR =1.154, P value =0.029), and tyrosine kinase 2 (TYK2) (HR =0.734, P value =0.041) were independent prognostic predictors for STAD patients.ConclusionsNOTCH1 could be a potential target for STAD. The mechanisms underpinning NOTCH1-medicated prognostic values of immune signatures should be further explored.

Protective effects of CRTH2 suppression in dry age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of central vision loss in the elderly. Oxidative stress-induced retinal pigment epithelium (RPE) cell apoptosis is a crucial pathogenic hallmark in AMD. Chemoattractant receptor-homologous molecule expressed on T helper type 2 cells (CRTH2), a prostaglandin (PG) D2 receptor, has been implicated in various pathophysiological events, especially inflammation and stress-induced cell apoptosis. However, its specific role in AMD is not fully understood. Here we studied the effect of CRTH2 on AMD. Our results showed that when stimulated by H2O2, CRTH2 mRNA expression in cells tended to increase. Flow cytometry revealed that the CRTH2 inhibitor could protect the RPE from apoptosis. After NaIO3 injection, a larger area of retinal degeneration was observed in wild-type mice than in CRTH2−/− mice. Optical coherence tomography (OCT) and Hematoxylin and Eosin (H&E) staining of retinal sections showed that sodium iodate-induced loss of photoreceptor cells was reduced in CRTH2−/− mice after treatment; TUNEL-positive cells were mostly found in the outer nuclear layer. In the control group, NaIO3 stimulation increased the number of TUNEL-positive cells, whereas the percentage of TUNEL-positive cells was significantly lower in CRTH2−/− mice. Similarly, the CRTH2 receptor inhibitor CAY10471 similarly inhibited sodium iodate-induced retinal damage. Our results suggest that targeting CRTH2 is a promising therapeutic strategy for the treatment of progressive retinal degeneration in AMD.

DP1 (Prostaglandin D2 Receptor 1) Activation Protects Against Vascular Remodeling and Vascular Smooth Muscle Cell Transition to Myofibroblasts in Angiotensin II-Induced Hypertension in Mice.

Vascular smooth muscle cell (VSMC) phenotype transition plays an essential role in vascular remodeling. PGD2 (Prostaglandin D2) is involved in cardiovascular inflammation. In this study, we aimed to investigates the role of DP1 (PGD2 receptor 1) on VSMC phenotype transition in vascular remodeling after Ang II (angiotensin II) infusion in mice. VSMC-specific DP1 knockout mice and DP1flox/flox mice were infused with Ang II for 28 days and systolic blood pressure was measured by noninvasive tail-cuff system. The arterial samples were applied to an unbiased proteome analysis. DP1f/f Myh11 (myosin heavy chain 11) CREERT2 R26mTmG/+ mice were generated for VSMC lineage tracing. Multiple genetic and pharmacological approaches were used to investigate DP1-mediated signaling in phenotypic transition of VSMCs in response to Ang II administration. DP1 knockout promoted vascular media thickness and increased systolic blood pressure after Ang II infusion by impairing Epac (exchange protein directly activated by cAMP)-1-mediated Rap-1 (Ras-related protein 1) activation. The DP1 agonist facilitated the interaction of myocardin-related transcription factor A and G-actin, which subsequently inhibited the VSMC transition to myofibroblasts through the suppression of RhoA (Ras homolog family member A)/ROCK-1 (Rho associated coiled-coil containing protein kinase 1) activity. Moreover, Epac-1 overexpression by lentivirus blocked the progression of vascular fibrosis in DP1 deficient mice in response to Ang II infusion. Our finding revealed a protective role of DP1 in VSMC switch to myofibroblasts by impairing the phosphorylation of MRTF (myocardin-related transcription factor)-A by ROCK-1 through Epac-1/Rap-1/RhoA pathway and thus inhibited the expression of collagen I, fibronectin, ED-A (extra domain A) fibronectin, and vinculin. Thus, DP1 activation has therapeutic potential for vascular fibrosis in hypertension.

Hematopoietic Prostaglandin D2 Synthase Controls Tfh/Th2 Communication and Limits Tfh Antitumor Effects

T follicular helper (Tfh) cells are a subset of CD4+ T cells essential in immunity and have a role in helping B cells produce antibodies against pathogens. However, their role during cancer progression remains unknown. The mechanism of action of Tfh cells remains elusive because contradictory data have been reported on their protumor or antitumor responses in human and murine tumors. Like Tfh cells, Th2 cells are also involved in humoral immunity and are regularly associated with tumor progression and poor prognosis, mainly through their secretion of IL4. Here, we showed that Tfh cells expressed hematopoietic prostaglandin D2 (PGD2) synthase in a pSTAT1/pSTAT3-dependent manner. Tfh cells produced PGD2, which led to recruitment of Th2 cells via the PGD2 receptor chemoattractant receptor homologous molecule expressed on Th type 2 cells (CRTH2) and increased their effector functions. This cross-talk between Tfh and Th2 cells promoted IL4-dependent tumor growth. Correlation between Th2 cells, Tfh cells, and hematopoietic PGD2 synthase was observed in different human cancers and associated with outcome. This study provides evidence that Tfh/Th2 cross-talk through PGD2 limits the antitumor effects of Tfh cells and, therefore, could serve as a therapeutic target.

Eicosanoid signaling as a therapeutic target in middle-aged mice with severe COVID-19

Abstract Coronavirus disease 2019 (COVID-19) is especially severe in aged populations. Resolution of the COVID-19 pandemic has been advanced by the recent development of SARS-CoV-2 vaccines, but vaccine efficacy is partly compromised by the recent emergence of SARS-CoV-2 variants with enhanced transmissibility. The emergence of these variants emphasizes the need for further development of anti-SARS-CoV-2 therapies, especially in aged populations. Here, we describe the isolation of a new set of highly virulent mouse-adapted viruses and use them to test a novel therapeutic drug useful in infections of aged animals. Similar to the human infection, aged mice infected with mouse-adapted SARS-CoV-2 develop more severe disease than young mice. In murine SARS, in which severity is also age-dependent, elevated levels of an eicosanoid, prostaglandin D2 (PGD2) and of a phospholipase, PLA2G2D, contributed to poor outcomes in aged mice. We now demonstrate that mRNA expression of PLA2G2D and PTGDR, a PGD2 receptor, and production of PGD2 increase in human PBMC-derived dendritic cells with aging and after SARS-CoV-2 infection. Using our virulent mouse-adapted SARS-CoV-2, we show that middle-aged mice lacking expression of PTGDR, or PLA2G2D are protected from severe disease. Further, treatment with a PTGDR antagonist, Asapiprant, protected aged mice from lethal infection. PTGDR antagonism is one of the first interventions in SARS-CoV-2-infected animals that specifically protects aged animals, suggesting that the PLA2G2D-PGD2/PTGDR pathway is a useful target for therapeutic interventions. This work is supported in part by grants from the National Institutes of Health USA (NIH) (P01 AI060699 (SP, PBM) and RO1 AI129269 (SP) and BIOAGE Labs (SP). The Pathology Core, is partially supported by the Center for Gene Therapy for Cystic Fibrosis (NIH Grant P30 DK-54759), and the Cystic Fibrosis Foundation. PBM is supported by the Roy J. Carver Charitable Trust.

Efficacy and Safety of Fevipiprant in Asthma: A Review and Meta-Analysis.

Fevipiprant is a non-steroidal oral prostaglandin D2 (PGD2) receptor 2 antagonist that reduces bronchial wall inflammation, possibly improving clinical outcomes in the asthmatic population.A systemic review search was conducted on PubMed, Embase, and Central Cochrane Registry. Randomized clinical trials were included with Fevipiprant as an intervention arm compared to placebo. For continuous variables, the standardized mean difference, and for discrete variables, Mantel-Haenszel Risk Ratio (MH Risk ratio) was used for analysis. Confidence interval of 95% and p-value < 0.05 was considered significant. The analysis was done using a random-effects model irrespective of heterogeneity. Heterogeneity was evaluated using the I2 statistic.A total of five articles, including seven trials, were included in the analysis. There was significant increase in post-bronchodilator forced expiratory volume in one second (FEV1) 0.249 (0.157-0.341), p<0.001 and pre-bronchodilator FEV1 0.115 (0.043 to 0.188), p=0.002. A decrease in asthma control questionnaire (ACQ) score of -0.124 (-0.187 to -0.062), p<0.001, was reported. Statistically significant asthma exacerbation reduction was reported in the high eosinophil count population with a daily dose of 450mg 0.77 relative risks (RR) (0.61-0.97). There was a positive deviation toward Fevipiprant 450mg dose for asthma reduction in the overall population, but it was not statistically significant. Fevipiprant produced a slight statistically significant reduction in asthma exacerbations in the high eosinophil count population with favorable deviation in the overall population. It significantly increased pre-and post-bronchodilator FEV1 and improved ACQ scores in treated patients. The benefits, though statistically significant, failed to translate into clinical importance.

AMG853, A Bispecific Prostaglandin D2 Receptor 1 and 2 Antagonist, Dampens Basophil Activation and Related Lupus-Like Nephritis Activity in Lyn-Deficient Mice.

Systemic lupus erythematosus is a complex autoimmune disease during which patients develop autoantibodies raised against nuclear antigens. During the course of the disease, by accumulating in secondary lymphoid organs (SLOs), basophils support autoreactive plasma cells to amplify autoantibody production. We have recently shown that murine lupus-like disease could be controlled by 10 days of oral treatment with a combination of prostaglandin D2 (PGD2) receptor (PTGDR) antagonists through the inhibition of basophil activation and recruitment to SLOs. Importantly, inhibiting solely PTGDR-1 or PTGDR-2 was ineffective, and the development of lupus-like disease could only be dampened by using antagonists for both PTGDR-1 and PTGDR-2. Here, we aimed at establishing a proof of concept that a clinically relevant bispecific antagonist of PTGDR-1 and PTGDR-2 could be efficient to treat murine lupus-like nephritis. Diseased Lyn-deficient female mice received treatment with AMG853 (vidupiprant, a bispecific PTGDR-1/PTGDR-2 antagonist) for 10 days. This led to the dampening of basophil activation and recruitment in SLOs and was associated with a decrease in plasmablast expansion and immunoglobulin E (IgE) production. Ten days of treatment with AMG853 was consequently sufficient in reducing the dsDNA-specific IgG titers, circulating immune complex glomerular deposition, and renal inflammation, which are hallmarks of lupus-like disease. Thus, bispecific PTGDR-1 and PTGDR-2 antagonists, such as AMG853, are a promising class of drugs for the treatment or prevention of organ damage in systemic lupus erythematosus.

Eicosanoid signalling blockade protects middle-aged mice from severe COVID-19.

Coronavirus disease 2019 (COVID-19) is especially severe in aged populations1. Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are highly effective, but vaccine efficacy is partly compromised by the emergence of SARS-CoV-2 variants with enhanced transmissibility2. The emergence of these variants emphasizes the need for further development of anti-SARS-CoV-2 therapies, especially for aged populations. Here we describe the isolation of highly virulent mouse-adapted viruses and use them to test a new therapeutic drug in infected aged animals. Many of the alterations observed in SARS-CoV-2 during mouse adaptation (positions 417, 484, 493, 498 and 501 of the spike protein) also arise in humans in variants of concern2. Their appearance during mouse adaptation indicates that immune pressure is not required for selection. For murine SARS, for which severity is also age dependent, elevated levels of an eicosanoid (prostaglandin D2 (PGD2)) and a phospholipase (phospholipase A2 group 2D (PLA2G2D)) contributed to poor outcomes in aged mice3,4. mRNA expression of PLA2G2D and prostaglandin D2 receptor (PTGDR), and production of PGD2 also increase with ageing and after SARS-CoV-2 infection in dendritic cells derived from human peripheral blood mononuclear cells. Using our mouse-adapted SARS-CoV-2, we show that middle-aged mice lacking expression of PTGDR or PLA2G2D are protected from severe disease. Furthermore, treatment with a PTGDR antagonist, asapiprant, protected aged mice from lethal infection. PTGDR antagonism is one of the first interventions in SARS-CoV-2-infected animals that specifically protects aged animals, suggesting that the PLA2G2D-PGD2/PTGDR pathway is a useful target for therapeutic interventions.

Results of a Phase 2b Trial With GB001, a Prostaglandin D2 Receptor 2 Antagonist, in Moderate to Severe Eosinophilic Asthma

Prostaglandin D2 receptor 2 (DP2) antagonists inhibit prostaglandin D2-induced effects, including recruitment and activation of cells driving asthma pathogenesis. However, challenges identifying target population and end points persist. What is the effect of the DP2 antagonist GB001 on asthma worsening in patients with moderate to severe eosinophilic asthma? In this phase IIb, randomized, double-blind, placebo-controlled, dose-ranging, parallel-group, multicenter study, GB001 or placebo was added to standard-of-care treatment in patients with moderate to severe asthma with a blood eosinophil count≥ 250 cells/μL. Patients aged≥ 18 years to< 75 years received one of four once-daily treatments (GB001 20mg, 40mg, or 60mg or placebo). The primary end point was the proportion of patients who experienced asthma worsening by 24weeks. Efficacy analyses were performed for the intention-to-treat population and safety analyses for patients who received at least one dose of study treatment. A total of 480 patients were treated. The ORs for asthma worsening for GB001 20mg, 40mg, and 60mg vsplacebo were 0.674 (95%CI, 0.398-1.142), 0.677 (95%CI, 0.399-1.149), and 0.651 (95%CI, 0.385-1.100), respectively. Analysis according to baseline blood eosinophil levels and/or fractional exhaled nitric oxide did not show greater treatment effects with higher values. Elevated liver aminotransferase levels and adverse events leading to discontinuation were more frequent for GB001 60mg than with placebo, GB001 20mg, and GB001 40mg. Although GB001 did not significantly reduce the odds of asthma worsening, reductions favoring GB001 were observed. Treatment effects were consistent regardless of high/low type 2 phenotype. The overall safety profile was acceptable, although GB001 60mg was associated with risk of liver injury. ClinicalTrials.gov; No.: NCT03683576; URL: www. gov.

Role of prostaglandin D2 receptors in the pathogenesis of abdominal aortic aneurysm formation.

Prostaglandin D2 (PGD2) released from immune cells or other cell types activates its receptors, D prostanoid receptor (DP)1 and 2 (DP1 and DP2), to promote inflammatory responses in allergic and lung diseases. Prostaglandin-mediated inflammation may also contribute to vascular diseases such as abdominal aortic aneurysm (AAA). However, the role of DP receptors in the pathogenesis of AAA has not been systematically investigated. In the present study, DP1-deficient mice and pharmacological inhibitors of either DP1 or DP2 were tested in two distinct mouse models of AAA formation: angiotensin II (AngII) infusion and calcium chloride (CaCl2) application. DP1-deficient mice [both heterozygous (DP1+/−) and homozygous (DP1−/−)] were protected against CaCl2-induced AAA formation, in conjunction with decreased matrix metallopeptidase (MMP) activity and adventitial inflammatory cell infiltration. In the AngII infusion model, DP1+/− mice, but not DP1−/− mice, exhibited reduced AAA formation. Interestingly, compensatory up-regulation of the DP2 receptor was detected in DP1−/− mice in response to AngII infusion, suggesting a potential role for DP2 receptors in AAA. Treatment with selective antagonists of DP1 (laropiprant) or DP2 (fevipiprant) protected against AAA formation, in conjunction with reduced elastin degradation and aortic inflammatory responses. In conclusion, PGD2 signaling contributes to AAA formation in mice, suggesting that antagonists of DP receptors, which have been extensively tested in allergic and lung diseases, may be promising candidates to ameliorate AAA.

Novel Evidence-Based Combination of Plant Extracts with Multitarget Mechanisms of Action for the Elimination of Hot Flashes during Menopause.

Hot flashes are considered the most bothersome complaint during menopause. Although hormone therapy is an effective option to relieve hot flashes, it has been associated with significant side effects. The aim of our study is to suggest a novel combination of different plant extracts with distinct mechanisms of action against hot flashes. We selected the rhizome of Glycyrrhiza glabra L. (Fabaceae), the rhizome of Actaea racemosa L. (Ranunculaceae), the aerial parts of Hypericum perforatum L. (Hypericaceae) to produce extracts rich in bioactive phytochemicals and the seed oil of Oenothera biennis L. (Onagraceae). We investigated their estrogenic and antioxidant potential and their inhibitory effect against prostaglandin D2 receptor 1 (DP1) as a novel mechanistic pathway for vasodilation in hot flashes, alone or in combination. The phytochemical footprint of the extracts was analyzed using HPLC-PDA and UPLC-HRMS. We observed that the tested extracts possess different mechanisms of action. A. racemosa exerts a beneficial activation of the estrogen receptor, H. perforatum possesses the highest antioxidant capacity and the seed oil of O. biennis inhibits the DP1 receptor. The triple combination in the optimal doses pertains to efficacy against all three mechanisms of action, serves as a multitarget plant-based therapy and could serve as a novel strategy for the alleviation of hot flashes in postmenopausal women.

Differential PTGDR2 Expression In Blood Cell Populations From Asthmatic Patients After Treatment With Anti-IL5 Or Anti-IL4R

Prostaglandin D2 receptor 2 (PTGDR2) is involved in allergic and eosinophilic asthma and has been considered a potential target for new therapies. A proof-of-concept study was designed to study the expression of PTGDR2 (CD294) in peripheral blood cells before and after treatment with biological therapy.

INKT cells are enriched in inflammatory infiltrates of chronic rhinosinusitis with nasal polyposis

iNKT cells, a subset of T cells, are potent effectors of Th2-inflammation that have been associated with a range of allergic diseases, but their involvement in chronic rhinosinusitis with nasal polyposis (CRSwNP) has not been well studied. We investigated their presence and expression of prostaglandin D2 and lipoxin-A4 receptors, Chemoattractant receptor-homologue-Th2 (CRTH2) and formyl-peptide Receptor-2 respectively, in nasal polyp tissue of patients with CRSwNP, as inflammatory regulator, in the presence of commensal bacteria, Staphylococcus aureus.

Phase 3b randomized controlled trial of fevipiprant in patients with nasal polyposis with asthma (THUNDER)

Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with asthma, particularly of late onset. Current treatment options for CRSwNP have limitations, and there is an unmet need for other safe and effective therapies. The aim of the THUNDER study was to determine the efficacy and safety of the prostaglandin D2 receptor 2 (DP2) antagonist fevipiprant in patients with CRSwNP and concomitant asthma, measured by improvement in nasal polyp score (primary end point), nasal congestion score, Sinonasal Outcome Test 22 score, and University of Pennsylvania Smell Identification Test score. THUNDER was a phase 3b, randomized, multicenter, double-blind, placebo-controlled, parallel-group, 16-week study of fevipiprant 150 mg or 450 mg once daily versus placebo. All patients received intranasal mometasone furoate 200 μg daily. Ninety-eight patients were randomly assigned to fevipiprant 150 mg (n= 32), fevipiprant 450 mg (n= 34), or placebo (n= 32). Mean (SE) change from baseline in nasal polyp score at week 16 was 0.20 (0.224) for fevipiprant 150 mg, -0.10 (0.216) for fevipiprant 450 mg, and 0.14 (0.233) for placebo. Mean treatment difference was 0.05 (95% confidence interval, -0.59, 0.70; adjusted P= .979) for fevipiprant 150 mg versus placebo and -0.25 (95% confidence interval, -0.88, 0.39; adjusted P= .656) for fevipiprant 450 mg versus placebo. There was no meaningful difference in the secondary end points for fevipiprant versus placebo. THUNDER provided no evidence of a role for fevipiprant in the treatment of patients with CRSwNP and asthma; future studies may establish a role for other DP2 antagonists, specifically in patients with aspirin-exacerbatedrespiratory disease.

THE INTERMEDIATION ROLE OF CENTRAL CYCLOOXYGENASE PRODUCTS TXA2, PGF2Α, PGE, AND PGD IN OREXIN-EVOKED CARDIOVASCULAR EFFECTS

Centrally injected some prostaglandins (PG) and orexin (OX) produce similar cardiovascular responses. We have recently reported that both central cyclooxygenase (COX) and central lipoxygenase (LOX) enzymes mediate the cardiovascular effects of OX. In the current study, we aimed to investigate the mediating effects of thromboxane (TX) A2, PGD, PGE, and PGF2, as COX pathway subproducts known to be active in cardiovascular control, on cardiovascular responses elicited by OX. Intracerebroventricular (i.c.v.) injection of OX increased cardiovascular levels in normotensive male Sprague Dawley rats. Moreover, central pretreatment with the TXA2 synthesis inhibitor furegrelate, PGF2α receptor antagonist, PGF2α-dimethylamine, PGE, and PGD receptor antagonist AH6809 partially attenuated the centrally administered OX -induced pressor and tachycardic cardiovascular responses in rats. In conclusion, our results show that i.c.v. injection of OX increases blood pressure and heart rate. Moreover, TXA2, PGF2α, PGE, and PGD mediate, at least in part, the centrally applied OX -evoked pressor and tachycardic responses. The results suggest that centrally injected OX -evoked pressor and tachycardia responses may also be mediated by arachidonic acid metabolites other than TXA2, PGF2α, PGE, and PGD.

Long-term safety and exploratory efficacy of fevipiprant in patients with inadequately controlled asthma: the SPIRIT randomised clinical trial

BackgroundThe prostaglandin D2 (PGD2) receptor 2 (DP2 receptor) pathway is an important regulator of the inflammatory cascade in asthma, which can be stimulated by allergic or non-allergic triggers. Fevipiprant is an oral, non-steroidal, highly selective, reversible antagonist of the DP2 receptor that inhibits the binding of PGD2 and its metabolites.MethodsSPIRIT, a 2-treatment period (52-week, double-blind and optional 104-week single-blind), randomised, placebo-controlled, multicentre, parallel-group study, assessed the long-term safety of fevipiprant (150 mg and 450 mg o.d.) added to standard of care in patients ≥ 12 years with uncontrolled asthma. Stratified block randomisation was used. Patients were randomised in an approximate ratio of 3:3:1 (fevipiprant 150 mg, fevipiprant 450 mg or placebo). Patients were either newly enrolled or had participated in a previous fevipiprant Phase 3 trial. Primary endpoints were: time-to-first treatment emergent adverse event (AE); serious AE; and AE leading to discontinuation from study treatment. Data from both treatment periods were combined for analyses. Data were collected during study site visits.ResultsIn total, 1093 patients were randomised to receive fevipiprant 150 mg, 1085 to fevipiprant 450 mg, and 360 to placebo. Overall, 1184 patients had ≥ 52 weeks’ treatment, while 163 received ≥ 104 weeks’ treatment. Both doses were well tolerated, with a safety profile similar to placebo both in new patients and in those enrolled from previous studies.In exploratory analyses, reduced rates of moderate-to-severe asthma exacerbations, increased time-to-first moderate-to-severe asthma exacerbation and improved FEV1 were observed for both doses of fevipiprant versus placebo; these were without multiplicity adjustment and should be interpreted with caution. SPIRIT was terminated early, on 16 December 2019, by the Sponsor.ConclusionsIn patients with uncontrolled asthma, the addition of fevipiprant had a favourable long-term safety profile.Trial registrationClinicaltrials.gov, NCT03052517, prospectively registered 23 January 2017, https://clinicaltrials.gov/ct2/show/NCT03052517.

Enantioselective Desymmetrization of 3-Substituted Oxetanes: An Efficient Access to Chiral 3,4-Dihydro-2H-1,4-benzoxazines.

Herein, we describe a versatile transition metal/oxidant free synthesis of the chiral 2H-1,4-benzoxazines through chiral phosphoric acid (CPA) catalyzed enantioselective desymmetrization of prochiral oxetanes (30 examples) in up to 99% yield and 99% enantioselectivity under mild reaction conditions. The reported strategy not only complements the conventional 2H-1,4-benzoxazine synthetic strategies but also provides access to key intermediates of therapeutic candidates, i.e., prostaglandin D2 receptor antagonist and M1 positive allosteric modulator (PAM) compound VU0486846.

GnRH neurons recruit astrocytes in infancy to facilitate network integration and sexual maturation.

Neurons that produce gonadotropin-releasing hormone (GnRH), which control fertility, complete their nose-to-brain migration by birth. However, their function depends on integration within a complex neuroglial network during postnatal development. Here, we show that rodent GnRH neurons use a prostaglandin D2 receptor DP1 signaling mechanism during infancy to recruit newborn astrocytes that 'escort' them into adulthood, and that the impairment of postnatal hypothalamic gliogenesis markedly alters sexual maturation by preventing this recruitment, a process mimicked by the endocrine disruptor bisphenol A. Inhibition of DP1 signaling in the infantile preoptic region, where GnRH cell bodies reside, disrupts the correct wiring and firing of GnRH neurons, alters minipuberty or the first activation of the hypothalamic-pituitary-gonadal axis during infancy, and delays the timely acquisition of reproductive capacity. These findings uncover a previously unknown neuron-to-neural-progenitor communication pathway and demonstrate that postnatal astrogenesis is a basic component of a complex set of mechanisms used by the neuroendocrine brain to control sexual maturation.