bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signalling profile differences: paliperidone versus risperidone
Authors: Clarke W P , Chavera T A , Silva M , Sullivan L C , Berg K A 
Published: August 2013

Background and PurposePaliperidone is an active metabolite of the second‐generation atypical antipsychotic, risperidone recently approved for the treatment of schizophrenia and schizoaffective disorder. Because paliperidone differs from risperidone by only a single hydroxyl group, questions have been raised as to whether there are significant differences in the effects elicited between these two drugs.Experimental ApproachWe compared the relative efficacies of paliperidone versus risperidone to regulate several cellular signalling pathways coupled to four selected GPCR targets that are important for either therapeutic or adverse effects: human dopamine D2, human serotonin 2A receptor subtype (5‐HT2A), human serotonin 2C receptor subtype and human histamine H1 receptors.Key ResultsWhereas the relative efficacies of paliperidone and risperidone were the same for some responses, significant differences were found for several receptor‐signalling systems, with paliperidone having greater or less relative efficacy than risperidone depending upon the receptor–response pair. Interestingly, for 5‐HT2A‐mediated recruitment of β‐arrestin, 5‐HT2A‐mediated sensitization of ERK, and dopamine D2‐mediated sensitization of adenylyl cyclase signalling, both paliperidone and risperidone behaved as agonists.Conclusions and ImplicationsThese results suggest that the single hydroxyl group of paliperidone promotes receptor conformations that can differ from those of risperidone leading to differences in the spectrum of regulation of cellular signal transduction cascades. Such differences in signalling at the cellular level could lead to differences between paliperidone and risperidone in therapeutic efficacy or in the generation of adverse effects.
Orexin/hypocretin receptor signalling: a functional perspective
Authors: Leonard C S , Kukkonen J P 
Published: August 2013

Multiple homeostatic systems are regulated by orexin (hypocretin) peptides and their two known GPCRs. Activation of orexin receptors promotes waking and is essential for expression of normal sleep and waking behaviour, with the sleep disorder narcolepsy resulting from the absence of orexin signalling. Orexin receptors also influence systems regulating appetite/metabolism, stress and reward, and are found in several peripheral tissues. Nevertheless, much remains unknown about the signalling pathways and targets engaged by native receptors. In this review, we integrate knowledge about the orexin receptor signalling capabilities obtained from studies in expression systems and various native cell types (as presented in Kukkonen and Leonard, this issue of British Journal of Pharmacology) with knowledge of orexin signalling in different tissues. The tissues reviewed include the CNS, the gastrointestinal tract, the pituitary gland, pancreas, adrenal gland, adipose tissue and the male reproductive system. We also summarize the findings in different native and recombinant cell lines, especially focusing on the different cascades in CHO cells, which is the most investigated cell line. This reveals that while a substantial gap exists between what is known about orexin receptor signalling and effectors in recombinant systems and native systems, mounting evidence suggests that orexin receptor signalling is more diverse than originally thought. Moreover, rather than being restricted to orexin receptor ‘overexpressing’ cells, this signalling diversity may be utilized by native receptors in a site‐specific manner.Linked ArticlesThis article is part of a themed section on Orexin Receptors. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue‐2
Pharmacological profiling of the TRPV3 channel in recombinant and native assays
Authors: Grubisha Olivera , Mogg Adrian J , Sorge Jessica L , Ball Laura‐Jayne , Sanger Helen , Ruble Cara L A , Folly Elizabeth A , Ursu Daniel , Broad Lisa M 
Published: August 2013

Background and PurposeTransient receptor potential vanilloid subtype 3 (TRPV3) is implicated in nociception and certain skin conditions. As such, it is an attractive target for pharmaceutical research. Understanding of endogenous TRPV3 function and pharmacology remains elusive as selective compounds and native preparations utilizing higher throughput methodologies are lacking. In this study, we developed medium‐throughput recombinant and native cellular assays to assess the detailed pharmacological profile of human, rat and mouse TRPV3 channels.Experimental ApproachMedium‐throughput cellular assays were developed using a Ca2+‐sensitive dye and a fluorescent imaging plate reader. Human and rat TRPV3 pharmacology was examined in recombinant cell lines, while the mouse 308 keratinocyte cell line was used to assess endogenous TRPV3 activity.Key ResultsA recombinant rat TRPV3 cellular assay was successfully developed after solving a discrepancy in the published rat TRPV3 protein sequence. A medium‐throughput, native, mouse TRPV3 keratinocyte assay was also developed and confirmed using genetic approaches. Whereas the recombinant human and rat TRPV3 assays exhibited similar agonist and antagonist profiles, the native mouse assay showed important differences, namely, TRPV3 activity was detected only in the presence of potentiator or during agonist synergy. Furthermore, the native assay was more sensitive to block by some antagonists.Conclusions and ImplicationsOur findings demonstrate similarities but also notable differences in TRPV3 pharmacology between recombinant and native systems. These findings offer insights into TRPV3 function and these assays should aid further research towards developing TRPV3 therapies.Linked ArticlesThis article is part of a themed section on the pharmacology of TRP channels. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue‐10
Selective, potent blockade of the IRE1 and ATF6 pathways by 4‐phenylbutyric acid analogues
Authors: Zhang Hui , Nakajima Shotaro , Kato Hironori , Gu Liubao , Yoshitomi Tatsuya , Nagai Kaoru , Shinmori Hideyuki , Kokubo Susumu , Kitamura Masanori 
Published: August 2013

Background and Purpose4‐Phenylbutyric acid (4‐PBA) is a chemical chaperone that eliminates the accumulation of unfolded proteins in the endoplasmic reticulum (ER). However, its chaperoning ability is often weak and unable to attenuate the unfolded protein response (UPR) in vitro or in vivo. To develop more potent chemical chaperones, we synthesized six analogues of 4‐PBA and evaluated their pharmacological actions on the UPR.Experimental ApproachNRK‐52E cells were treated with ER stress inducers (tunicamycin or thapsigargin) in the presence of each of the 4‐PBA analogues; the suppressive effects of these analogues on the UPR were assessed using selective indicators for individual UPR pathways.Key Results2‐POAA‐OMe, 2‐POAA‐NO2 and 2‐NOAA, but not others, suppressed the induction of ER stress markers GRP78 and CHOP. This suppressive effect was more potent than that of 4‐PBA. Of the three major UPR branches, the IRE1 and ATF6 pathways were markedly blocked by these compounds, as indicated by suppression of XBP1 splicing, inhibition of UPRE and ERSE activation, and inhibition of JNK phosphorylation. Unexpectedly, however, these agents did not inhibit phosphorylation of PERK and eIF2α triggered by ER stress. These compounds dose‐dependently inhibited the early activation of NF‐κB in ER stress‐exposed cells. 2‐POAA‐OMe and 2‐POAA‐NO2 also inhibited ER stress‐induced phosphorylation of Akt.Conclusion and ImplicationsThe 4‐PBA analogues 2‐POAA‐OMe, 2‐POAA‐NO2 and 2‐NOAA strongly inhibited activation of the IRE1 and ATF6 pathways and downstream pathogenic targets, including NF‐κB and Akt, in ER stress‐exposed cells. These compounds may be useful for therapeutic intervention in ER stress‐related pathological conditions.
Pharmacological characterization of a novel centrally permeable P2X7 receptor antagonist: JNJ‐47965567
Authors: Bhattacharya Anindya , Wang Qi , Ao Hong , Shoblock James R , Lord Brian , Aluisio Leah , Fraser Ian , Nepomuceno Diane , Neff Robert A , Welty Natalie , Lovenberg Timothy W , Bonaventure Pascal , Wickenden Alan D , Letavic Michael A 
Published: August 2013

Background and PurposeAn increasing body of evidence suggests that the purinergic receptor P2X, ligand‐gated ion channel, 7 (P2X7) in the CNS may play a key role in neuropsychiatry, neurodegeneration and chronic pain. In this study, we characterized JNJ‐47965567, a centrally permeable, high‐affinity, selective P2X7 antagonist.Experimental ApproachWe have used a combination of in vitro assays (calcium flux, radioligand binding, electrophysiology, IL‐1β release) in both recombinant and native systems. Target engagement of JNJ‐47965567 was demonstrated by ex vivo receptor binding autoradiography and in vivo blockade of Bz‐ATP induced IL‐1β release in the rat brain. Finally, the efficacy of JNJ‐47965567 was tested in standard models of depression, mania and neuropathic pain.Key ResultsJNJ‐47965567 is potent high affinity (pKi 7.9 ± 0.07), selective human P2X7 antagonist, with no significant observed speciation. In native systems, the potency of the compound to attenuate IL‐1β release was 6.7 ± 0.07 (human blood), 7.5 ± 0.07 (human monocytes) and 7.1 ± 0.1 (rat microglia). JNJ‐47965567 exhibited target engagement in rat brain, with a brain EC50 of 78 ± 19 ng·mL−1 (P2X7 receptor autoradiography) and functional block of Bz‐ATP induced IL‐1β release. JNJ‐47965567 (30 mg·kg−1) attenuated amphetamine‐induced hyperactivity and exhibited modest, yet significant efficacy in the rat model of neuropathic pain. No efficacy was observed in forced swim test.Conclusion and ImplicationsJNJ‐47965567 is centrally permeable, high affinity P2X7 antagonist that can be used to probe the role of central P2X7 in rodent models of CNS pathophysiology.
Effect of chirality and lipophilicity in the functional activity of evodiamine and its analogues at TRPV1 channels
Authors: De Petrocellis Luciano , Schiano Moriello Aniello , Fontana Gabriele , Sacchetti Alessandro , Passarella Daniele , Appendino Giovanni , Di Marzo Vincenzo 
Published: August 2013

Background and PurposeEvodiamine, a racemic quinazolinocarboline alkaloid isolated from the traditional Chinese medicine Evodiae fructus, has been reported to act as an agonist of the transient receptor potential vanilloid type‐1 (TRPV1) cation channel both in vitro and in vivo. Evodiamine is structurally different from all known TRPV1 activators, and has significant clinical potential as a thermogenic agent. Nevertheless, the molecular bases for its actions are still poorly understood.Experimental ApproachTo investigate the structure‐activity relationships of evodiamine, the natural racemate was resolved, and a series of 23 synthetic analogues was prepared, using as the end point the intracellular Ca2+ elevation in HEK‐293 cells stably overexpressing either the human or the rat recombinant TRPV1.Key ResultsS‐(+) evodiamine was more efficacious and potent than R‐(−) evodiamine, and a new potent lead (Evo30) was identified, more potent than the reference TRPV1 agonist, capsaicin. In general, potency and efficacy correlated with the lipophilicity of the analogues. Like other TRPV1 agonists, several synthetic analogues could efficiently desensitize TRPV1 to activation by capsaicin.Conclusions and ImplicationsEvodiamine qualifies as structurally unique lead structure to develop new potent TRPV1 agonists/desensitizers.Linked ArticlesThis article is part of a themed section on the pharmacology of TRP channels. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue‐10
3,3′‐Diindolylmethane ameliorates experimental hepatic fibrosis via inhibiting miR‐21 expression
Authors: Zhang Zhengping , Gao Zhongfei , Hu Wei , Yin Shan , Wang Chunming , Zang Yuhui , Chen Jiangning , Zhang Junfeng , Dong Lei 
Published: August 2013

Background and PurposeHepatic fibrosis is a type of liver disease characterized by excessive collagen deposition produced by activated hepatic stellate cells (HSCs), and no appropriate drug treatment is available clinically. The microRNA, miR‐21 exhibits an important role in the pathogenesis and progression of hepatic fibrosis. 3,3′‐Diindolylmethane (DIM) is a natural autolytic product in plants and can down‐regulate miR‐21 expression. Here we have assessed the therapeutic effects of DIM against hepatic fibrosis and investigated the underlying mechanisms.Experimental ApproachThe effects of DIM on HSC activation were measured by analysing the expression of α‐smooth muscle actin and collagen I in both HSC‐T6 cell line and primary HSCs. Expression of miR‐21 was also measured after DIM treatment and the therapeutic effect of DIM was further studied in vivo, using the model of hepatic fibrosis induced by thioacetamide in mice. The antagonist oligonucleotide, antagomir‐21, was also used to suppress the effects of miR‐21.Key ResultsDIM suppressed the central TGF‐β signalling pathway underlying HSC activation by down‐regulating the expression of miR‐21. The decreased miR‐21 expression was achieved by inhibiting the activity of the transcription factor, AP‐1. Moreover, DIM blunted the activation phenotype of primary HSCs. Administration of DIM in vivo attenuated liver fibrosis induced by thioacetamide, as assessed by collagen deposition and profiles of profibrogenic markers.Conclusions and ImplicationsDIM shows potential as a therapeutic agent for the treatment of hepatic fibrosis.
Orexin/hypocretin receptor signalling cascades
Authors: Kukkonen J P , Leonard C S 
Published: August 2013

Orexin (hypocretin) peptides and their two known G‐protein‐coupled receptors play essential roles in sleep–wake control and powerfully influence other systems regulating appetite/metabolism, stress and reward. Consequently, drugs that influence signalling by these receptors may provide novel therapeutic opportunities for treating sleep disorders, obesity and addiction. It is therefore critical to understand how these receptors operate, the nature of the signalling cascades they engage and their physiological targets. In this review, we evaluate what is currently known about orexin receptor signalling cascades, while a sister review (Leonard & Kukkonen, this issue) focuses on tissue‐specific responses. The evidence suggests that orexin receptor signalling is multifaceted and is substantially more diverse than originally thought. Indeed, orexin receptors are able to couple to members of at least three G‐protein families and possibly other proteins, through which they regulate non‐selective cation channels, phospholipases, adenylyl cyclase, and protein and lipid kinases. In the central nervous system, orexin receptors produce neuroexcitation by postsynaptic depolarization via activation of non‐selective cation channels, inhibition of K+ channels and activation of Na+/Ca2+ exchange, but they also can stimulate the release of neurotransmitters by presynaptic actions and modulate synaptic plasticity. Ca2+ signalling is also prominently influenced by these receptors, both via the classical phospholipase C−Ca2+ release pathway and via Ca2+ influx, mediated by several pathways. Upon longer‐lasting stimulation, plastic effects are observed in some cell types, while others, especially cancer cells, are stimulated to die. Thus, orexin receptor signals appear highly tunable, depending on the milieu in which they are operating.Linked ArticlesThis article is part of a themed section on Orexin Receptors. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue‐2
Central 5‐HT1A receptor‐mediated modulation of heart rate dynamics and its adjustment by conditioned and unconditioned fear in mice
Authors: Youn Jiun , Hager Torben , Misane Ilga , Pieneman Anton W , Jansen René F , Ögren Sven Ove , Meyer Michael , Stiedl Oliver 
Published: August 2013

Background and PurposeThe beat‐by‐beat fluctuation (dynamics) of heart rate (HR) depends on centrally mediated control of the autonomic nervous system (ANS) reflecting the physiological state of an organism. 5‐HT1A receptors are implicated in affective disorders,associated with ANS dysregulation which increases cardiac risk but their role in autonomic HR regulation under physiological conditions is insufficiently characterized.Experimental ApproachThe effects of subcutaneously administered 5‐HT1A receptor ligands on HR dynamics were investigated in C57BL/6 mice during stress‐free conditions and emotional challenge (recall of fear conditioned to an auditory stimulus and novelty exposure) using time domain and non‐linear HR analyses.Key ResultsPre‐training treatment with of 8‐OH‐DPAT (0.5 mg·kg−1, s.c.) prevented conditioned tachycardia in the retention test indicating impaired fear memory. Pretest 5‐HT1A receptor activation by 8‐OH‐DPAT (0.5 but not 0.1 and 0.02 mg·kg−1) caused bradycardia and increased HR variability. 8‐OH‐DPAT (0.5 mg·kg−1) lowered the unconditioned and conditioned tachycardia from ∼750 to ∼550 bpm, without changing the conditioned HR response to the sound. 8‐OH‐DPAT induced profound QT prolongation and bradyarrhythmic episodes. Non‐linear analysis indicated a pathological state of HR dynamics after 8‐OH‐DPAT (0.5 mg·kg−1) with ANS hyperactivation impairing HR adaptability. The 5‐HT1A receptor antagonist WAY‐100635 (0.03 mg·kg−1) blocked these effects of 8‐OH‐DPAT.Conclusions and ImplicationsPre‐training 5‐HT1A receptor activation by 8‐OH‐DPAT (0.5 mg·kg−1) impaired memory of conditioned auditory fear based on an attenuated HR increase, whereas pretest administration did not prevent the fear‐conditioned HR increase but induced pathological HR dynamics through central ANS dysregulation with cardiac effects similar to acute SSRI overdose.
UDP induces intestinal epithelial migration via the P2Y6 receptor
Authors: Nakamura Tatsuro , Murata Takahisa , Hori Masatoshi , Ozaki Hiroshi 
Published: August 2013

Background and PurposeExtracellular nucleotides are released at high concentrations from damaged cells and function through P2 receptor activation. Intestinal epithelial restitution, which is defined as cell migration independent of cell proliferation, is an important initial step in the process of wound healing. In this study, we investigated the role of extracellular nucleotides in intestinal epithelial migratory responses.Experimental ApproachWound‐healing and trans‐well migration assays were performed with a rat intestinal epithelial cell line (IEC‐6). The concentrations of extracellular nucleotides released from injured IEC‐6 cells were measured by HPLC. TGF‐β expression was assessed by RT‐PCR and elisa.Key ResultsScratching the monolayer of IEC‐6 cells induced cell migration. Pretreatment with apyrase or MRS2578, a selective P2Y6 antagonist, inhibited the wound‐induced cell migration. Among the cellular nucleotides, only ATP and uridine 5'‐diphosphate (UDP) were detected in the culture medium after cell wounding. Exogenously applied UDP dose‐dependently enhanced the migration more effectively than ATP but did not induce proliferation. In addition, cell wounding and UDP increased the expression of TGF‐β, and both the wound‐induced and UDP‐enhanced migration were inhibited by MRS2578 or ALK5Inhibitor (ALK5i), a TGF‐β receptor blocker. Furthermore, cell wounding and UDP stimulation up‐regulated the expression of P2Y6 receptor mRNA, and this effect was suppressed by MRS2578 or ALK5i.Conclusion and ImplicationsWound‐induced UDP evokes intestinal epithelial restitution by activation of P2Y6 receptors, which mediates de novo synthesis of TGF‐β. In addition, the expression of P2Y6 receptors is increased by cell wounding and UDP, which constitutes a positive‐feedback loop for mucosal repair.
Interictal interleukin‐17A levels are elevated and correlate with seizure severity of epilepsy patients
Authors: Mao Ling‐Yan , Ding Jing , Peng Wei‐Feng , Ma Yu , Zhang Yu‐Hao , Fan Wei , Wang Xin 
Published: August 2013

SummaryInterleukin 17A (IL‐17A) is implicated in the pathogenesis of several neuroimmunologic diseases. We aimed to evaluate the relationship between IL‐17A and seizure severity in patients with epilepsy. Seventy patients with probable symptomatic epilepsy and 68 healthy controls were included. Interictal serum IL‐17A and related cytokine (IL‐23, IL‐6, IL‐1β, interferon gamma (IFN‐γ), and IL‐10) levels were measured. The relationship between seizure severity and cytokine concentrations was assessed by Spearman correlation and multivariate linear regression test. IL‐17A levels in the cerebrospinal fluid (CSF) were tested in 30 additional patients with epilepsy, either in the postictal or interictal period and 15 patients with idiopathic inflammatory demyelinating diseases (IIDDs). Interictal serum IL‐17A levels were significantly elevated in patients with epilepsy compared to controls. IL‐6, IFN‐γ, and IL‐1β levels were also markedly elevated. Spearman correlation analysis revealed positive correlation between IL‐17A, IL‐6 levels and Veterans Administration Seizures Frequency and Severity Rating Scale score(VA score); IFN‐γ, IL‐10 levels, and National Hospital Seizure Severity Scale (NHS3) score. In addition, IL‐17A levels correlated significantly with seizure frequency. Multivariate linear regression test showed that only IL‐17A levels were independently positively correlated with VA scores (B = 0.288, p = 0.027). Postictal IL‐17A levels in the CSF were significantly elevated compared to interictal patients and patients with IIDDs. Our results suggest that interictal IL‐17A levels correlated highly with seizure severity.
Source localization of rhythmic ictal EEG activity: A study of diagnostic accuracy following STARD criteria
Authors: Beniczky Sándor , Lantz Göran , Rosenzweig Ivana , Åkeson Per , Pedersen Birthe , Pinborg Lars H. , Ziebell Morten , Jespersen Bo , Fuglsang‐Frederiksen Anders 
Published: August 2013

SummaryPurposeAlthough precise identification of the seizure‐onset zone is an essential element of presurgical evaluation, source localization of ictal electroencephalography (EEG) signals has received little attention. The aim of our study was to estimate the accuracy of source localization of rhythmic ictal EEG activity using a distributed source model.MethodsSource localization of rhythmic ictal scalp EEG activity was performed in 42 consecutive cases fulfilling inclusion criteria. The study was designed according to recommendations for studies on diagnostic accuracy (STARD). The initial ictal EEG signals were selected using a standardized method, based on frequency analysis and voltage distribution of the ictal activity. A distributed source model—local autoregressive average (LAURA)—was used for the source localization. Sensitivity, specificity, and measurement of agreement (kappa) were determined based on the reference standard—the consensus conclusion of the multidisciplinary epilepsy surgery team. Predictive values were calculated from the surgical outcome of the operated patients. To estimate the clinical value of the ictal source analysis, we compared the likelihood ratios of concordant and discordant results. Source localization was performed blinded to the clinical data, and before the surgical decision.Key FindingsReference standard was available for 33 patients. The ictal source localization had a sensitivity of 70% and a specificity of 76%. The mean measurement of agreement (kappa) was 0.61, corresponding to substantial agreement (95% confidence interval (CI) 0.38–0.84). Twenty patients underwent resective surgery. The positive predictive value (PPV) for seizure freedom was 92% and the negative predictive value (NPV) was 43%. The likelihood ratio was nine times higher for the concordant results, as compared with the discordant ones.SignificanceSource localization of rhythmic ictal activity using a distributed source model (LAURA) for the ictal EEG signals selected with a standardized method is feasible in clinical practice and has a good diagnostic accuracy. Our findings encourage clinical neurophysiologists assessing ictal EEGs to include this method in their armamentarium.