bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gastrin promotes human colon cancer cell growth via CCK‐2 receptor‐mediated cyclooxygenase‐2 induction and prostaglandin E2 production
Authors: Colucci Rocchina , Blandizzi Corrado , Tanini Marzia , Vassalle Cristina , Breschi Maria Cristina , Tacca Mario Del 
Published: January 2005

The present study investigates the effects of gastrin‐17 on human colon cancer HT‐29 cells to examine whether gastrin receptor (CCK‐2), cyclooxygenase (COX‐1, COX‐2) isoforms and prostaglandin receptor pathways interact to control cell growth.
Reverse transcription (RT)–polymerase chain reaction (PCR) analysis demonstrated that HT‐29 cells are endowed with the naïve expression of CCK‐2 receptor (short splice variant), COX‐1, COX‐2 and prostaglandin EP4 receptor, but not gastrin.
Gastrin‐17 significantly promoted cell growth and DNA synthesis. Both these stimulating effects were abolished by L‐365,260 or GV150013 (CCK‐2 receptor antagonists), but were unaffected by SC‐560 (COX‐1 inhibitor). L‐745,337 (COX‐2 inhibitor) or AH‐23848B (EP4 receptor antagonist) partly reversed gastrin‐17‐induced cell growth, while they fully antagonized the enhancing action on DNA synthesis.
HT‐29 cells responded to gastrin‐17 with a significant increase in prostaglandin E2 release. This enhancing effect was completely counteracted by L‐365,260, GV150013 or L‐745,337, while it was insensitive to cell incubation with SC‐560.
Exposure of HT‐29 cells to gastrin‐17 was followed by an increased phosphorylation of both extracellular regulated kinases (ERK‐1/ERK‐2) and Akt. Moreover, gastrin‐17 enhanced the transcriptional activity of COX‐2 gene promoter and stimulated COX‐2 expression. These latter effects were antagonized by L‐365,260 or GV150013, and could be blocked also by PD98059 (inhibitor of ERK‐1/ERK‐2 phosphorylation) or wortmannin (inhibitor of phosphatidylinositol 3‐kinase). Analogously, gastrin‐17‐induced prostaglandin E2 release was prevented by PD98059 or wortmannin.
The present results suggest that (a) in human colon cancer cells endowed with CCK‐2 receptors, gastrin‐17 is able to enhance the transcriptional activity of COX‐2 gene through the activation of ERK‐1/ERK‐2‐ and phosphatidylinositol 3‐kinase/Akt‐dependent pathways; (b) these stimulant actions lead to downstream increments of COX‐2 expression, followed by prostaglandin E2 production and EP4 receptor activation; (c) the recruitment of COX‐2/prostaglandin pathways contributes to the growth‐promoting actions exerted by gastrin‐17.

British Journal of Pharmacology (2005) 144, 338–348. doi:10.1038/sj.bjp.0706053
Excessive stimulation of poly(ADP‐ribosyl)ation contributes to endothelial dysfunction in pre‐eclampsia
Authors: Crocker Ian P , Kenny Louise C , Thornton Wayne A , Szabo Csaba , Baker Philip N 
Published: January 2005

Pre‐eclampsia is a serious pregnancy disorder associated with widespread activation of the maternal vascular endothelium. Recent evidence implicates a role for oxidative stress in the aetiology of this condition.
Reactive oxygen species, particularly superoxide anions, invokes endothelial cell activation through many pathways. Oxidant‐induced cell injury triggers the activation of nuclear enzyme poly(ADP‐ribose) polymerase (PARP) leading to endothelial dysfunction in various pathophysiological conditions (reperfusion, shock, diabetes).
We have studied whether the loss of endothelial function in pre‐eclampsia is dependent on PARP activity. Endothelium‐dependent responses of myometrial arteries were tested following exposure to either plasma from women with pre‐eclampsia or normal pregnant women in the presence and absence of a novel potent inhibitor of PARP, PJ34. Additional effects of plasma and PJ34 inhibition were identified in microvascular endothelial cell cultures.
In myometrial arteries, PARP inhibition blocked the attenuation of endothelium‐dependent responses following exposure to plasma from women with pre‐eclampsia. In endothelial cell cultures, plasma from pre‐eclamptics induced measurable oxidative stress and a concomitant increase in PARP activity and reduction in cellular ATP. Again, these biochemical changes were reversed by PJ34.
These results suggest that PARP activity plays a pathogenic role in the development of endothelial dysfunction in pre‐eclampsia and promotes PARP inhibition as a potential therapy in this condition.

British Journal of Pharmacology (2005) 144, 772–780. doi:10.1038/sj.bjp.0706055
Anxiogenic properties of an inverse agonist selective for α3 subunit‐containing GABAA receptors
Authors: Atack John R , Hutson Peter H , Collinson Neil , Marshall George , Bentley Graham , Moyes Christopher , Cook Susan M , Collins Ian , Wafford Keith , McKernan Ruth M , Dawson Gerard R 
Published: January 2005

α3IA (6‐(4‐pyridyl)‐5‐(4‐methoxyphenyl)‐3‐carbomethoxy‐1‐methyl‐1H‐pyridin‐2‐one) is a pyridone with higher binding and functional affinity and greater inverse agonist efficacy for GABAA receptors containing an α3 rather than an α1, α2 or α5 subunit. If doses are selected that minimise the occupancy at these latter subtypes, then the in vivo effects of α3IA are most probably mediated by the α3 subtype.
α3IA has good CNS penetration in rats and mice as measured using a [3H]Ro 15‐1788 in vivo binding assay.
At doses in rats that produce relatively low levels of occupancy (12%) in the cerebellum (i.e. α1‐containing receptors), α3IA (30 mg kg−1 i.p.), like the nonselective partial inverse agonist N‐methyl‐β‐carboline‐3‐carboxamide (FG 7142), not only caused behavioural disruption in an operant, chain‐pulling assay but was also anxiogenic in the elevated plus maze, an anxiogenic‐like effect that could be blocked with the benzodiazepine antagonist Ro 15‐1788 (flumazenil).
Neurochemically, α3IA (30 mg kg−1 i.p.) as well as FG 7142 (15 mg kg−1 i.p.) increased the concentration of the dopamine metabolite 3,4‐dihydroxyphenylacetic acid in rat medial prefrontal cortex by 74 and 68%, respectively, relative to vehicle‐treated animals, a response that mimicked that seen following immobilisation stress.
Taken together, these data demonstrate that an inverse agonist selective for GABAA receptors containing an α3 subunit is anxiogenic, and suggest that since α3‐containing GABAA receptors play a role in anxiety, then agonists selective for this subtype should be anxiolytic.

British Journal of Pharmacology (2005) 144, 357–366. doi:10.1038/sj.bjp.0706056
Conserved structural, pharmacological and functional properties among the three human and five zebrafish α2‐adrenoceptors
Authors: Ruuskanen Jori O , Laurila Jonne , Xhaard Henri , Rantanen Ville‐Veikko , Vuoriluoto Karoliina , Wurster Siegfried , Marjamäki Anne , Vainio Minna , Johnson Mark S , Scheinin Mika 
Published: January 2005

Zebrafish has five distinct α2‐adrenoceptors. Two of these, α2Da and α2Db, represent a duplicated, fourth α2‐adrenoceptor subtype, while the others are orthologue of the human α2A‐, α2B‐ and α2C‐adrenoceptors. Here, we have compared the pharmacological properties of these receptors to infer structural determinants of ligand interactions.
The zebrafish α2‐adrenoceptors were expressed in Chinese hamster ovary cells and tested in competitive ligand binding assays and in a functional assay (agonist‐stimulated [35S]GTPγS binding). The affinity results were used to cluster the receptors and, separately, the ligands using both principal component analysis and binary trees.
The overall ligand binding characteristics, the order of potency and efficacy of the tested agonists and the G‐protein coupling of the zebrafish and human α2‐adrenoceptors, separated by ∼350 million years of evolution, were found to be highly conserved. The binding affinities of the 20 tested ligands towards the zebrafish α2‐adrenoceptors are generally comparable to those of their human counterparts, with a few compounds showing up to 40‐fold affinity differences.
The α2A orthologues and the zebrafish α2D duplicates clustered as close pairs, but the relationships between the orthologues of α2B and α2C were not clearly defined. Applied to the ligands, our clustering methods segregated the ligands based on their chemical structures and functional properties. As the ligand binding pockets formed by the transmembrane helices show only minor differences among the α2‐adrenoceptors, we suggest that the second extracellular loop – where significant sequence variability is located – might contribute significantly to the observed affinity differences.

British Journal of Pharmacology (2005) 144, 165–177. doi:10.1038/sj.bjp.0706057
2‐Furoyl‐LIGRL‐NH2, a potent agonist for proteinase‐activated receptor‐2, as a gastric mucosal cytoprotective agent in mice
Authors: Kawabata Atsufumi , Oono Yuko , Yonezawa Daiki , Hiramatsu Kaori , Inoi Naoki , Sekiguchi Fumiko , Honjo Masami , Hirofuchi Michiko , Kanke Toru , Ishiwata Hiroyuki 
Published: January 2005

Proteinase‐activated receptor‐2 (PAR2), expressed in capsaicin‐sensitive sensory neurons, plays a protective role in gastric mucosa. The present study evaluated gastric mucosal cytoprotective effect of 2‐furoyl‐LIGRL‐NH2, a novel highly potent PAR2 agonist, in ddY mice and in wild‐type and PAR2‐knockout mice of C57BL/6 background.
Gastric mucosal injury was created by oral administration of HCl/ethanol solution in the mice. The native PAR2‐activating peptide SLIGRL‐NH2, administered intraperitoneally (i.p.) at 0.3–1 μmol kg−1 in combination with amastatin, an aminopeptidase inhibitor, but not alone, revealed gastric mucosal protection in ddY mice, which was abolished by ablation of capsaicin‐sensitive sensory neurons.
I.p. administration of 2‐furoyl‐LIGRL‐NH2 at 0.1 μmol kg−1, without combined treatment with amastatin, exhibited gastric mucosal cytoprotective activity in ddY mice, the potency being much greater than SLIGRL‐NH2 in combination with amastatin. This effect was also inhibited by capsaicin pretreatment.
Oral administration of 2‐furoyl‐LIGRL‐NH2 at 0.003–0.03 μmol kg−1 also protected against gastric mucosal lesion in a capsaicin‐reversible manner in ddY mice.
I.p. 2‐furoyl‐LIGRL‐NH2 at 0.1–0.3 μmol kg−1 caused prompt salivation in anesthetized mice, whereas its oral administration at 0.003–1 μmol kg−1 was incapable of eliciting salivation.
In wild‐type, but not PAR2‐knockout, mice of C57BL/6 background, i.p. administration of 2‐furoyl‐LIGRL‐NH2 caused gastric mucosal protection.
Thus, 2‐furoyl‐LIGRL‐NH2 is considered a potent and orally available gastric mucosal protective agent. Our data also substantiate a role for PAR2 in gastric mucosal protection and the selective nature of 2‐furoyl‐LIGRL‐NH2.

British Journal of Pharmacology (2005) 144, 212–219. doi:10.1038/sj.bjp.0706059
Alpha‐2 adrenoceptor subtypes: are more better?
Authors: Bylund David B 
Published: January 2005

The discovery of an additional duplicated alpha‐2 adrenoceptor subtype in the zebrafish raises a pesky nomenclature issue, as well as questions about the functions of the alpha‐2 adrenoceptors in the zebrafish and how many alpha‐2 receptors does an organism really need.British Journal of Pharmacology (2005) 144, 159–160. doi:10.1038/sj.bjp.0706060
LY294002 and rapamycin co‐operate to inhibit T‐cell proliferation
Authors: Breslin Elaine M , White Paul C , Shore Angharad M , Clement Mathew , Brennan Paul 
Published: January 2005

T‐cell proliferation is critical for mounting an effective adaptive immune response. It is regulated by signals through the T‐cell receptor, through co‐stimulation and through cytokines such as interleukin‐2 (IL‐2). Phosphatidylinositol 3‐kinase (PI3K) lies downstream of each of these pathways and has been directly implicated in the regulation of lymphocyte proliferation.
In this study, we have shown that PI3K regulates cyclin D2 and cyclin D3, the first cell cycle proteins induced in T‐cell proliferation, transcriptionally and post‐transcriptionally. In T‐lymphoblasts, LY294002, a PI3K inhibitor, prevents the induction of both D‐type cyclin mRNA and protein, while rapamycin inhibits the induction of protein. Rapamycin inhibits mammalian target of rapamycin (mTOR), which lies downstream of PI3K.
Furthermore, our data show that the combination of LY294002 and rapamycin results in a co‐operative inhibition of T‐cell proliferation. This co‐operation occurs in Kit225 cells stimulated with IL‐2, and also in resting peripheral blood lymphocytes stimulated with antibodies to the T‐cell receptor in the presence and absence of antibodies to CD28.
These data indicate that PI3K regulates T‐cell proliferation in response to diverse stimuli, and suggest that combinations of inhibitors, perhaps isoform‐selective, may be useful as alternative immunosuppressive therapies.

British Journal of Pharmacology (2005) 144, 791–800. doi:10.1038/sj.bjp.0706061
The pore‐forming subunit of the KATP channel is an important molecular target for LPS‐induced vascular hyporeactivity in vitro
Authors: O'Brien Alastair J , Thakur Gita , Buckley James F , Singer Mervyn , Clapp Lucie H 
Published: January 2005

ATP‐sensitive K+ (KATP) channel activation is implicated in the vascular hyporeactivity occurring in septic shock. However, channel inhibition with the sulphonylurea receptor (SUR) antagonist, glibenclamide (Glib) fails to reverse lipopolysaccharide (LPS)‐induced vascular hyporeactivity in vitro. We investigated whether inhibitors that act by binding to the KATP channel pore could be effective.
Ring segments of endothelium‐intact rat mesenteric artery were incubated with LPS in culture media for either 6 or 20 h before contractile responses to phenylephrine were assessed in the absence or presence of KATP channel inhibitors.
The pore‐forming subunit inhibitors barium chloride (BaCl2; 300 μM) and PNU‐37883A (1 μM) significantly reversed hyporeactivity at both time points, although less so at 20 h. In contrast, the SUR inhibitors, Glib (10 μM), tolbutamide (Tolb) (1 mM) and PNU‐99963 (1 μM) were ineffective. In LPS‐incubated tissues, Glib and Tolb antagonised contractions to the thromboxane A2 mimetic, U46619 (9,11‐dideoxy‐9α, 11α‐methanoepoxy prostaglandin F2α) (10−7 M), whereas the pinacidil‐derived inhibitor, PNU‐99963, did not.
Contractions to 60 mM KCl were unaffected by LPS at 6 h, but were significantly depressed by LPS at 20 h, suggesting that K+‐channel‐independent pathways contribute to hyporeactivity at the later time point.
The inducible nitric oxide synthase (iNOS) inhibitor, 1400 W (10 μM) and Tolb inhibited the production of nitrite induced by LPS, whereas BaCl2 and PNU‐37883A had no effect.
In conclusion, KATP channels contribute to LPS‐induced vascular hyporeactivity via the iNOS pathway in rat mesenteric artery. The effectiveness of pore inhibitors over SUR inhibitors of the KATP channel suggests altered SUR function following LPS administration, which cannot be explained by thromboxane receptor inhibition.

British Journal of Pharmacology (2005) 144, 367–375. doi:10.1038/sj.bjp.0706065
TNFα reduces tachykinin, PGE2‐dependent, relaxation of the cultured mouse trachea by increasing the activity of COX‐2
Authors: Bachar Ofir , Rose Andrew C , Adner Mikael , Wang Xudong , Prendergast Clodagh E , Kempf Ashley , Shankley Nigel P , Cardell Lars‐Olaf 
Published: January 2005

Chronic inflammation is a central feature of asthma. The inflammatory cytokine tumour necrosis factor α (TNFα) has been implicated in this disease, and is known to alter airway smooth muscle functionally.
The aim of this study was to investigate the influence of TNFα on tachykinin‐induced airway relaxation. Mouse tracheae were cultured in the absence and presence of TNFα for 1 or 4 days.
In the absence of TNFα, substance P (SP) and neurokinin A (NKA) induced comparable levels of relaxation in fresh and cultured segments. Functional studies with selective antagonists/inhibitors indicated that the relaxation was mediated by the NK1 receptor coupled to cyclooxygenase (COX)‐2 activation and subsequent release of prostaglandin E2 (PGE2). TNFα attenuated SP‐ and NKA‐induced relaxation in a time‐ and concentration‐dependent manner, decreasing the ability of PGE2 to relax tissues.
Further studies indicated that TNFα elevated COX‐2 activity and that concomitant inhibition of COX‐2 reversed TNFα‐attenuated PGE2 relaxation. Culture with PGE2 decreased SP‐ and PGE2‐mediated relaxation, further implicating the activity of COX‐2 in the attenuation of tachykinin signalling.
Gene expression analysis demonstrated that TNFα increased the expression of smooth muscle COX‐2, PGE2 synthase and EP2 receptor mRNA, and decreased the expression of the EP4 receptor.
Overall, these results show that NK1 receptor‐mediated relaxation induced by PGE2 is attenuated by prolonged TNFα stimulation. Increased COX‐2 activity induced by TNFα appears to be central to this process.

British Journal of Pharmacology (2005) 144, 220–230. doi:10.1038/sj.bjp.0706067
Malonate induces cell death via mitochondrial potential collapse and delayed swelling through an ROS‐dependent pathway
Authors: Fernandez‐Gomez Francisco J , Galindo Maria F , Gómez‐Lázaro Maria , Yuste Victor J , Comella Joan X , Aguirre Norberto , Jordán Joaquín 
Published: January 2005

Herein we study the effects of the mitochondrial complex II inhibitor malonate on its primary target, the mitochondrion.
Malonate induces mitochondrial potential collapse, mitochondrial swelling, cytochrome c (Cyt c) release and depletes glutathione (GSH) and nicotinamide adenine dinucleotide coenzyme (NAD(P)H) stores in brain‐isolated mitochondria.
Although, mitochondrial potential collapse was almost immediate after malonate addition, mitochondrial swelling was not evident before 15 min of drug presence. This latter effect was blocked by cyclosporin A (CSA), Ruthenium Red (RR), magnesium, catalase, GSH and vitamin E.
Malonate added to SH‐SY5Y cell cultures produced a marked loss of cell viability together with the release of Cyt c and depletion of GSH and NAD(P)H concentrations. All these effects were not apparent in SH‐SY5Y cells overexpressing Bcl‐xL.
When GSH concentrations were lowered with buthionine sulphoximine, cytoprotection afforded by Bcl‐xL overexpression was not evident anymore.
Taken together, all these data suggest that malonate causes a rapid mitochondrial potential collapse and reactive oxygen species production that overwhelms mitochondrial antioxidant capacity and leads to mitochondrial swelling. Further permeability transition pore opening and the subsequent release of proapoptotic factors such as Cyt c could therefore be, at least in part, responsible for malonate‐induced toxicity.

British Journal of Pharmacology (2005) 144, 528–537. doi:10.1038/sj.bjp.0706069
Prediction of the risk of Torsade de Pointes using the model of isolated canine Purkinje fibres
Authors: Champeroux Pascal , Viaud Karen , El Amrani Abdel Ilah , Fowler John Sinclair Lawrence , Martel Eric , Le Guennec Jean‐Yves , Richard Serge 
Published: January 2005

Torsade de Pointes (TdP) is a well‐described major risk associated with various kinds of drugs. However, prediction of this risk is still uncertain both in preclinical and clinical trials. We tested 45 reference compounds on the model of isolated canine Purkinje fibres. Of them, 22 are clearly associated and/or labelled with a risk of TdP, and 13 others are drugs with published clinical evidence of QT prolongation, with only one or two exceptional cases of TdP. The 10 remaining drugs are without reports of TdP and QT prolongation.
The relevance of different indicators such as APD90 increase, reverse use dependency, action potential triangulation or effect on Vmax was evaluated by comparison with available clinical data. Finally, a complex algorithm called TDPscreen™ and based on two subalgorithms corresponding to particular electrophysiological patterns was defined.
This latter algorithm enabled a clear separation of drugs into three groups: (A) drugs with numerous or several reports (>2 cases) of TdP, (B) drugs causing QT prolongation and/or TdP only, the latter at a very low frequency (2 cases), (C) drugs without reports of TdP or QT prolongation.
The use of such an algorithm combined with a database accrued from reference compounds with available clinical data is suggested as a basis for testing new candidate drugs in the early stages of development for proarrhythmic risk prediction.

British Journal of Pharmacology (2005) 144, 376–385. doi:10.1038/sj.bjp.0706070
A comparative study on the acute and long‐term effects of MDMA and 3,4‐dihydroxymethamphetamine (HHMA) on brain monoamine levels after i.p. or striatal administration in mice
Authors: Escobedo Isabel , O'Shea Esther , Orio Laura , Sanchez Veronica , Segura Mireia , de la Torre Rafael , Farre Magi , Green Alfred Richard , Colado Maria Isabel 
Published: January 2005

This study investigated whether the immediate and long‐term effects of 3,4‐methylenedioxymethamphetamine (MDMA) on monoamines in mouse brain are due to the parent compound and the possible contribution of a major reactive metabolite, 3,4‐dihydroxymethamphetamine (HHMA), to these changes. The acute effect of each compound on rectal temperature was also determined.
MDMA given i.p. (30 mg kg−1, three times at 3‐h intervals), but not into the striatum (1, 10 and 100 μg, three times at 3‐h intervals), produced a reduction in striatal dopamine content and modest 5‐HT reduction 1 h after the last dose. MDMA does not therefore appear to be responsible for the acute monoamine release that follows its peripheral injection.
HHMA does not contribute to the acute MDMA‐induced dopamine depletion as the acute central effects of MDMA and HHMA differed following i.p. injection. Both compounds induced hyperthermia, confirming that the acute dopamine depletion is not responsible for the temperature changes.
Peripheral administration of MDMA produced dopamine depletion 7 days later. Intrastriatal MDMA administration only produced a long‐term loss of dopamine at much higher concentrations than those reached after the i.p. dose and therefore bears little relevance to the neurotoxicity. This indicates that the long‐term effect is not attributable to the parent compound. HHMA also appeared not to be responsible as i.p. administration failed to alter the striatal dopamine concentration 7 days later.
HHMA was detected in plasma, but not in brain, following MDMA (i.p.), but it can cross the blood–brain barrier as it was detected in the brain following its peripheral injection.
The fact that the acute changes induced by i.p. or intrastriatal HHMA administration differed indicates that HHMA is metabolised to other compounds which are responsible for changes observed after i.p. administration.

British Journal of Pharmacology (2005) 144, 231–241. doi:10.1038/sj.bjp.0706071