Publications by authors named "Jens Wagner"

19 Publications

  • Page 1 of 1

Memory trace interference impairs recall in a mouse model of Alzheimer's disease.

Nat Neurosci 2020 08 8;23(8):952-958. Epub 2020 Jun 8.

Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.

In Alzheimer's disease (AD), hippocampus-dependent memories underlie an extensive decline. The neuronal ensemble encoding a memory, termed engram, is partially recapitulated during memory recall. Artificial activation of an engram can restore memory in a mouse model of early AD, but its fate and the factors that render the engram nonfunctional are yet to be revealed. Here, we used repeated two-photon in vivo imaging to analyze fosGFP transgenic mice (which express enhanced GFP under the Fos promoter) performing a hippocampus-dependent memory task. We found that partial reactivation of the CA1 engram during recall is preserved under AD-like conditions. However, we identified a novelty-like ensemble that interfered with the engram and thus compromised recall. Mimicking a novelty-like ensemble in healthy mice was sufficient to affect memory recall. In turn, reducing the novelty-like signal rescued the recall impairment under AD-like conditions. These findings suggest a novel mechanistic process that contributes to the deterioration of memories in AD.
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http://dx.doi.org/10.1038/s41593-020-0652-4DOI Listing
August 2020

The diphenylpyrazole compound anle138b blocks Aβ channels and rescues disease phenotypes in a mouse model for amyloid pathology.

EMBO Mol Med 2018 01;10(1):32-47

Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany

Alzheimer's disease is a devastating neurodegenerative disease eventually leading to dementia. An effective treatment does not yet exist. Here we show that oral application of the compound anle138b restores hippocampal synaptic and transcriptional plasticity as well as spatial memory in a mouse model for Alzheimer's disease, when given orally before or after the onset of pathology. At the mechanistic level, we provide evidence that anle138b blocks the activity of conducting Aβ pores without changing the membrane embedded Aβ-oligomer structure. In conclusion, our data suggest that anle138b is a novel and promising compound to treat AD-related pathology that should be investigated further.
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http://dx.doi.org/10.15252/emmm.201707825DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5760857PMC
January 2018

Dysfunction of Somatostatin-Positive Interneurons Associated with Memory Deficits in an Alzheimer's Disease Model.

Neuron 2016 Oct 15;92(1):114-125. Epub 2016 Sep 15.

Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany. Electronic address:

Alzheimer's disease (AD) is characterized by cognitive decline and neuronal network dysfunction, but the underlying mechanisms remain unknown. In the hippocampus, microcircuit activity during learning and memory processes is tightly controlled by O-LM interneurons. Here, we investigated the effect of beta-amyloidosis on O-LM interneuron structural and functional connectivity, combining two-photon in vivo imaging of synaptic morphology, awake Ca imaging, and retrograde mono-transsynaptic rabies tracing. We find severely impaired synaptic rewiring that occurs on the O-LM interneuron input and output level in a mouse model of AD. Synaptic rewiring that occurs upon fear learning on O-LM interneuron input level is affected in mice with AD-like pathology. This process requires the release of acetylcholine from septo-hippocampal projections. We identify decreased cholinergic action on O-LM interneurons in APP/PS1 mice as a key pathomechanism that contributes to memory impairment in a mouse model, with potential relevance for human AD.
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http://dx.doi.org/10.1016/j.neuron.2016.08.034DOI Listing
October 2016

Reducing tau aggregates with anle138b delays disease progression in a mouse model of tauopathies.

Acta Neuropathol 2015 Nov 6;130(5):619-31. Epub 2015 Oct 6.

German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.

Pathological tau aggregation leads to filamentous tau inclusions and characterizes neurodegenerative tauopathies such as Alzheimer's disease and frontotemporal dementia and parkinsonism linked to chromosome 17. Tau aggregation coincides with clinical symptoms and is thought to mediate neurodegeneration. Transgenic mice overexpressing mutant human P301S tau exhibit many neuropathological features of human tauopathies including behavioral deficits and increased mortality. Here, we show that the di-phenyl-pyrazole anle138b binds to aggregated tau and inhibits tau aggregation in vitro and in vivo. Furthermore, anle138b treatment effectively ameliorates disease symptoms, increases survival time and improves cognition of tau transgenic PS19 mice. In addition, we found decreased synapse and neuron loss accompanied by a decreased gliosis in the hippocampus. Our results suggest that reducing tau aggregates with anle138b may represent an effective and promising approach for the treatment of human tauopathies.
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http://dx.doi.org/10.1007/s00401-015-1483-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612332PMC
November 2015

Quantitative Real-Time Quaking-Induced Conversion Allows Monitoring of Disease-Modifying Therapy in the Urine of Prion-Infected Mice.

J Neuropathol Exp Neurol 2015 Sep;74(9):924-33

From the Center for Neuropathology and Prion Research, Ludwig-Maximilians University, Munich (SS, JW, GMK, AG); German Center for Neurodegenerative Diseases, Bonn (JW); and NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Gottingen (SR, AL, CG), Germany.

Prion diseases are fatal neurodegenerative diseases characterized by accumulation of the pathogenic prion protein PrP in the brain. We established quantitative real-time quaking-induced conversion for the measurement of minute amounts of PrP in body fluids such as urine. Using this approach, we monitored the efficacy of antiprion therapy by quantifying the seeding activity of PrP from the brain and urine of mice after prion infection. We found that the aggregation inhibitor anle138b decreased the levels of PrP in the brain and urine. Importantly, variations of PrP levels in the urine closely corresponded to those in the brain. Our findings indicate that quantification of urinary PrP enables measurement of prion disease progression in body fluids and can substitute for immunodetection in brain tissue. We expect PrP quantification biologic fluids (such as urine and cerebrospinal fluid) with quantitative real-time quaking-induced conversion to emerge as a valuable noninvasive diagnostic tool for monitoring disease progression and the efficacy of therapeutic approaches in animal studies and human clinical trials of prion diseases. Moreover, highly sensitive methods for quantifying pathologic aggregate seeds might provide novel molecular biomarkers for other neurodegenerative diseases that may involve prion-like mechanisms (protein aggregation and spreading), such as Alzheimer disease and Parkinson disease.
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http://dx.doi.org/10.1097/NEN.0000000000000233DOI Listing
September 2015

Long-term in vivo imaging of dendritic spines in the hippocampus reveals structural plasticity.

J Neurosci 2014 Oct;34(42):13948-53

German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany

Hippocampal function is important for learning and memory. During memory processing, hippocampal CA1 neurons play a crucial role by integrating excitatory synaptic input from CA3 and the entorhinal cortex. These neurons receive excitatory input almost exclusively on dendritic spines. The formation and elimination--structural plasticity--of dendritic spines reflect wiring changes within the hippocampal network. Despite the relevance of the hippocampus in learning and memory, most in vivo data on structural plasticity derive from cortical regions. We established a chronic hippocampal window approach using two-photon microscopy to visualize dendritic spines throughout all CA1 hippocampal layers and over a time course of weeks. Moreover, even granule cells in dentate gyrus could be reliably detected. We found that the spine density in stratum radiatum (∼1.1 per micrometer) remained stable over weeks. However, a small fraction (3.4%) of spines were formed and eliminated between imaging sessions, which demonstrated that spines of CA1 neurons exhibit structural plasticity in adult mice. In addition, we tested for possible inflammatory or behavioral side effects of hippocampal window implantation. Mice exhibited a transient increase in microgliosis and astrogliosis, which declined within a few weeks. We did not detect any difference in behavioral performance in an open-field and contextual fear-conditioning paradigm. In conclusion, hippocampal long-term two-photon imaging revealed structural plasticity of dendritic spines in CA1 pyramidal neurons. This approach may provide a powerful tool to analyze changes in neuronal network rewiring during hippocampal learning and memory processes in health and disease.
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http://dx.doi.org/10.1523/JNEUROSCI.1464-14.2014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6705298PMC
October 2014

Anle138b: a novel oligomer modulator for disease-modifying therapy of neurodegenerative diseases such as prion and Parkinson's disease.

Acta Neuropathol 2013 Jun 19;125(6):795-813. Epub 2013 Apr 19.

Zentrum für Neuropathologie und Prionforschung, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 23, 81377, Munich, Germany.

In neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and prion diseases, deposits of aggregated disease-specific proteins are found. Oligomeric aggregates are presumed to be the key neurotoxic agent. Here we describe the novel oligomer modulator anle138b [3-(1,3-benzodioxol-5-yl)-5-(3-bromophenyl)-1H-pyrazole], an aggregation inhibitor we developed based on a systematic high-throughput screening campaign combined with medicinal chemistry optimization. In vitro, anle138b blocked the formation of pathological aggregates of prion protein (PrP(Sc)) and of α-synuclein (α-syn), which is deposited in PD and other synucleinopathies such as dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). Notably, anle138b strongly inhibited all prion strains tested including BSE-derived and human prions. Anle138b showed structure-dependent binding to pathological aggregates and strongly inhibited formation of pathological oligomers in vitro and in vivo both for prion protein and α-synuclein. Both in mouse models of prion disease and in three different PD mouse models, anle138b strongly inhibited oligomer accumulation, neuronal degeneration, and disease progression in vivo. Anle138b had no detectable toxicity at therapeutic doses and an excellent oral bioavailability and blood-brain-barrier penetration. Our findings indicate that oligomer modulators provide a new approach for disease-modifying therapy in these diseases, for which only symptomatic treatment is available so far. Moreover, our findings suggest that pathological oligomers in neurodegenerative diseases share structural features, although the main protein component is disease-specific, indicating that compounds such as anle138b that modulate oligomer formation by targeting structure-dependent epitopes can have a broad spectrum of activity in the treatment of different protein aggregation diseases.
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http://dx.doi.org/10.1007/s00401-013-1114-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3661926PMC
June 2013

Synthesis of benzamide derivatives and their evaluation as antiprion agents.

Bioorg Med Chem 2012 Aug 20;20(16):5001-11. Epub 2012 Jun 20.

Dipartimento di Chimica Farmaceutica e Tossicologica, Università di Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy.

A new set of 5-(2-(pyrrolidin-1-yl)acetamido)-N-butyl-2-(substituted)benzamide and 5-(2-(piperidin-1-yl)acetamido)-N-butyl-2-(substituted) benzamide derivatives were synthesized in which as structural features the 2-(1-pyrrolidinyl)- or 2-(1-piperidyl)acetylamino group or a diphenylether moiety are associated to a benzamide scaffold. Their binding affinity for human PrP(C) and inhibition of its conversion into PrP(Sc) were determined in vitro; moreover, the antiprion activity was assayed by inhibition of PrP(Sc) accumulation in scrapie-infected mouse neuroblastoma cells (ScN2a) and scrapie mouse brain (SMB) cells. The results clearly indicate the benzamide derivatives as attractive lead compounds for the development of potential therapeutic agents against prion disease.
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http://dx.doi.org/10.1016/j.bmc.2012.06.026DOI Listing
August 2012

Activated protein C in patients with septic shock: a consecutive case series.

Int J Clin Pharm 2012 Feb 27;34(1):23-6. Epub 2011 Nov 27.

Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany.

Background: The recommendation to restrict the use of activated protein C (APC) to patients with severe sepsis and the highest risk of death originates from large trials that were subject to major exclusion criteria.

Objective: To investigate the effect of APC on prognosis in 'real world' patients.

Method: Consecutive case series at tertiary care hospital including 63 adults with septic shock and multi-organ failure treated with APC (24 mcg/kg/h) for up to 96 h in addition to standard care.

Results: Median APACHE score was 35 (quartiles, 29-41), mean number of failing organs was 4 (quartiles, 4-5), and overall 30-day mortality was 48%. Independent predictors of 30-day mortality risk were the number of failing organs and number of antibiotics given. Risk of dying was significantly lower if compared with the mortality rates expected per APACHE II score category (P for trend per 5-point increment <0.001). This association was most prominent in patients with an APACHE II score of 30-44. Intracranial or major bleeding during APC treatment did not occur.

Conclusion: These findings support the view that targeting APC treatment to patients with septic shock and a very high risk is a sound and safe approach. However, due to lack of consistent evidence from randomized studies APC was recently removed from the market.
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http://dx.doi.org/10.1007/s11096-011-9588-9DOI Listing
February 2012

Receptors for acylethanolamides-GPR55 and GPR119.

Prostaglandins Other Lipid Mediat 2009 Sep 15;89(3-4):105-11. Epub 2009 Jul 15.

Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA.

Acylethanolamides are lipid substances widely distributed in the body, generated from a membrane phospholipid precursor, N-acylphosphatidylethanolamine (NAPE). The recent identification of arachidonoyl ethanolamide (anandamide or AEA) as an endogenous cannabinoid ligand has focused attention on acylethanolamides, which has further increased with the subsequent identification of related additional acylethanolamides with signaling function, such as oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). Most of the biological functions of anandamide are mediated by the two G protein-coupled cannabinoid receptors identified to date, CB(1) and CB(2), with the transient receptor potential vanilloid-1 receptor being an additional potential target. There has been increasing pharmacological evidence for the existence of additional cannabinoid receptors, with the orphan G protein-coupled receptor GPR55 being the most actively scrutinized, and is one of the subjects of this review. The other receptor reviewed here is GPR119, which can recognize OEA and PEA. These two acylethanolamides, although structurally related to anandamide, do not interact with classical cannabinoid receptors. Instead, they have high affinity for the nuclear receptor PPARalpha, which is believed to mediate many of their biological effects.
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http://dx.doi.org/10.1016/j.prostaglandins.2009.07.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2751869PMC
September 2009

Progression of left ventricular functional abnormalities in hypertensive patients with heart failure: an ultrasonic two-dimensional speckle tracking study.

J Am Soc Echocardiogr 2008 Dec;21(12):1309-17

Department of Cardiology, Wroclaw Medical University, Wroclaw, Poland.

Objective: Two-dimensional (2-D) strain imaging is a novel echocardiographic technique for myocardial function evaluation. We sought to investigate left ventricular (LV) systolic function in patients with heart failure caused by hypertension using a 2-D strain approach and to validate this method against Doppler strain measurements.

Methods: The study population comprised 81 patients (66.4 +/- 7.4 years) with hypertension in New York Heart Association (NYHA) class I to IV and 20 healthy controls.

Results: Decreased longitudinal strain was demonstrated in the basal septal segment in NYHA I, in the basal and mid septal and basal lateral segments in NYHA II, and in all segments in NYHA III and IV. Radial and circumferential strain were reduced in patients with NYHA III and IV. Independent predictors of strain were duration of HT, LV mass index, LV end-diastolic volume index, and systolic blood pressure. The agreement between 2-D and Doppler strain remained within acceptable ranges (mean difference +/- 1 standard deviation: 0.61%-1.92% +/- 2.38%-2.92% for longitudinal strain in particular segments and 4.98% +/- 5.26% for radial strain).

Conclusion: In hypertensive patients, (1) LV longitudinal systolic function progressively deteriorates from NYHA I to IV and abnormalities commence in the basal septum, (2) LV radial and circumferential systolic impairment appears in NYHA III and IV, and (3) 2-D strain measurement provides a feasible tool for the quantitation of LV systolic performance.
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http://dx.doi.org/10.1016/j.echo.2008.10.006DOI Listing
December 2008

Use of laccase as a novel, versatile reporter system in filamentous fungi.

Appl Environ Microbiol 2006 Jul;72(7):5020-6

Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany.

Laccases are copper-containing enzymes which oxidize phenolic substrates and transfer the electrons to oxygen. Many filamentous fungi contain several laccase-encoding genes, but their biological roles are mostly not well understood. The main interest in laccases in biotechnology is their potential to be used to detoxify phenolic substances. We report here on a novel application of laccases as a reporter system in fungi. We purified a laccase enzyme from the ligno-cellulolytic ascomycete Stachybotrys chartarum. It oxidized the artificial substrate 2,2'-azino-di-(3-ethylbenzthiazolinsulfonate) (ABTS). The corresponding gene was isolated and expressed in Aspergillus nidulans, Aspergillus niger, and Trichoderma reesei. Heterologously expressed laccase activity was monitored in colorimetric enzyme assays and on agar plates with ABTS as a substrate. The use of laccase as a reporter was shown in a genetic screen for the isolation of improved T. reesei cellulase production strains. In addition to the laccase from S. charatarum, we tested the application of three laccases from A. nidulans (LccB, LccC, and LccD) as reporters. Whereas LccC oxidized ABTS (Km = 0.3 mM), LccD did not react with ABTS but with DMA/ADBP (3,5-dimethylaniline/4-amino-2,6-dibromophenol). LccB reacted with DMA/ADBP and showed weak activity with ABTS. The different catalytic properties of LccC and LccD allow simultaneous use of these two laccases as reporters in one fungal strain.
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http://dx.doi.org/10.1128/AEM.00060-06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489370PMC
July 2006

2-Arachidonylglycerol acting on CB1 cannabinoid receptors mediates delayed cardioprotection induced by nitric oxide in rat isolated hearts.

J Cardiovasc Pharmacol 2006 May;47(5):650-5

Department of Internal Medicine 1, Center of Cardiovascular Medicine, University of Würzburg, Würzburg, Germany.

Endocannabinoids have been implicated in protective effects in the heart and brain, but the mechanism of possible infarct-size-reducing effects remains controversial. Using a model of delayed preconditioning (PC), rats received the nitric oxide (NO) donor nitroglycerin (0.15 mg/h/kg) for 24 hours via transdermal application. Two days later, rat isolated perfused hearts were subjected to global, no-flow ischemia (20 min), and reperfusion (120 min). Cannabinoid receptor antagonists were given before no-flow throughout the protocol. Endocannabinoids were detected by liquid chromatography and mass spectrometry. NO-induced PC reduced the left ventricular infarct size from 40.9 +/- 3.9% to 27.5 +/- 3.8% (P < 0.05). Treatment with the specific CB1 cannabinoid receptor antagonist AM-251 (0.3 microM) prevented the protective effect of PC on infarct size (40.2 +/- 4.7%, P > 0.05 vs. controls). On the contrary, the specific CB2 receptor antagonist AM-630 (0.3 microM) did not alter infarct size (31.6 +/- 6.3%, P > 0.05 vs. PC alone). Recovery of left ventricular developed pressure and coronary flow was incomplete in control and NO-pretreated hearts and not consistently altered by cannabinoid receptor antagonists. PC increased the heart tissue content of the endocannabinoid 2-arachidonylglycerol (2-AG) from 4.6 +/- 1.0 nmol/g in controls to 12.0 +/- 2.1 nmol/g (P < 0.05). Tissue levels of the endocannabinoid arachidonylethanolamide (anandamide) remained unchanged (19.8 +/- 3.9 pmol/g vs. 19.5 +/- 4.8 pmol/g). 2-AG (1 microM) or its metabolically stable derivative noladinether (0.1 microM), given 30 minutes before ischemia/reperfusion in unpreconditioned hearts, mimicked the cardioprotective effects of PC and reduced infarct size. We conclude that delayed PC through transdermal nitroglycerin application increases the production of the endocannabinoid 2-AG which elicits protective effects against myocardial infarction via CB1 cannabinoid receptors which represents one new mechanism of NO-mediated PC.
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http://dx.doi.org/10.1097/01.fjc.0000211752.08949.ebDOI Listing
May 2006

Coronary vasodilator effects of endogenous cannabinoids in vasopressin-preconstricted unpaced rat isolated hearts.

J Cardiovasc Pharmacol 2005 Sep;46(3):348-55

Department of Internal Medicine I, Center of Cardiovascular Medicine, University of Würzburg, Würzburg, Germany.

The mechanisms by which cannabinoids alter coronary vascular tone and cardiac performance are controversial. We investigated the effects of various cannabinoids in spontaneously beating Langendorff-perfused rat hearts. Bolus injections of anandamide (0.1-1 micromol) caused no change in coronary flow (CF) or left ventricular systolic pressure (LVSP). In hearts preperfused with vasopressin to induce vasoconstrictor tone, anandamide or the selective CB1 receptor agonist ACEA (1-100 nmol) dose-dependently increased CF by up to 267% and LVSP by 20 mm Hg. The metabolically stable endocannabinoid derivatives, R-methanandamide and noladin ether, displayed similar effects. In contrast, Delta-THC (10-100 nmol), the major psychoactive ingredient of cannabis, strongly decreased CF and LVSP. The CB2 receptor agonist JWH-133 (10-100 nmol) elicited vasodilator and positive inotropic effects only at higher doses. The CB1 antagonists SR141716A and AM-251 as well as the potassium channel inhibitors tetraethylammonium and iberiotoxin blocked the anandamide-induced increases in CF and LVSP, whereas the CB2 antagonist SR144528 and the putative "CB3 antagonist" O-1918 did not have an inhibitory effect. Immunohistochemistry revealed the presence of cardiac CB1 but no CB2 receptors. Anandamide and 2-arachidonoylglycerol were detected in heart tissue. However, combined application of fatty acid amidohydrolase inhibitors and the transport inhibitor AM-404 to augment tissue levels of endocannabinoids was without effect on CF or LVSP. We conclude that in the rat isolated heart with reestablished vasoconstrictor tone, cannabinoids including anandamide elicit coronary vasodilation and a secondary increase in contractility via CB1 receptors and potassium channels.
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http://dx.doi.org/10.1097/01.fjc.0000175437.87283.f2DOI Listing
September 2005

The endocannabinoid arachidonyl ethanolamide (anandamide) increases pulmonary arterial pressure via cyclooxygenase-2 products in isolated rabbit lungs.

Am J Physiol Heart Circ Physiol 2005 Dec 29;289(6):H2491-6. Epub 2005 Jul 29.

Medizinische Universitaetsklinik, Josef-Schneider-Str. 2, 97080 Würzburg, Germany.

Several cannabinoids elicit systemic vasodilation, mainly via CB1 cannabinoid and vanilloid receptors. However, effects in the pulmonary circulation are unknown. Using the isolated, ventilated, buffer-perfused rabbit lung, we have shown that the endocannabinoids arachidonyl ethanolamide (anandamide) and 2-arachidonyl glycerol (2-AG) dose-dependently increase pulmonary arterial pressure (+19.9 +/- 3.4 mmHg, 5 microM, and +39.5 +/- 10.8 mmHg, 0.4 microM, respectively). 2-AG induced lung edema. The CB1 receptor antagonist AM-251 (0.1 and 5 microM) and the VR1 vanilloid receptor antagonist capsazepine (10 microM) failed to reduce anandamide's effects. The metabolically stable anandamide and 2-AG analogs R-methanandamide and noladin ether, Delta9-tetrahydrocannabinol, and the synthetic cannabinoid HU-210, which is no arachidonic acid product, were without effect. The unspecific cyclooxygenase (COX) inhibitor aspirin (100 microM, P < 0.001) and the specific COX-2 inhibitor nimesulide (10 microM, P < 0.01) completely prevented pulmonary hypertension after 5 microM anandamide. COX-2 RNA was detected in rabbit lungs. The synthetic thromboxane receptor antagonist SQ 29,548 was without effect, but the specific EP1 prostanoid receptor antagonist SC-19220 (100 microM) inhibited the pressure increase after anandamide (P < 0.05). PCR analysis detected fatty acid amidohydrolase (FAAH), an enzyme that degrades endocannabinoids, in rabbit lung tissue. Furthermore, the specific FAAH inhibitor methyl arachidonyl fluorophosphonate (0.1 microM) blocked pressure effects of anandamide (P < 0.01). Finally, anandamide (99 +/- 55 pmol/g) and 2-AG (19.6 +/- 8.4 nmol/g) were found in native lungs. We conclude that anandamide increases pulmonary arterial pressure via COX-2 metabolites following enzymatic degradation by FAAH into arachidonic acid products.
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http://dx.doi.org/10.1152/ajpheart.00718.2005DOI Listing
December 2005

Cannabinoid antagonist SR-141716 inhibits endotoxic hypotension by a cardiac mechanism not involving CB1 or CB2 receptors.

Am J Physiol Heart Circ Physiol 2004 Aug 1;287(2):H595-600. Epub 2004 Apr 1.

National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892-8115, USA.

Endocannabinoids and CB1 receptors have been implicated in endotoxin (LPS)-induced hypotension: LPS stimulates the synthesis of anandamide in macrophages, and the CB1 antagonist SR-141716 inhibits the hypotension induced by treatment of rats with LPS or LPS-treated macrophages. Recent evidence indicates the existence of cannabinoid receptors distinct from CB1 or CB2 that are inhibited by SR-141716 but not by other CB1 antagonists such as AM251. In pentobarbital-anesthetized rats, intravenous injection of 10 mg/kg LPS elicited hypotension associated with profound decreases in cardiac contractility, moderate tachycardia, and an increase in lower body vascular resistance. Pretreatment with 3 mg/kg SR-141716 prevented the hypotension and decrease in cardiac contractility, slightly attenuated the increase in peripheral resistance, and had no effect on the tachycardia caused by LPS, whereas pretreatment with 3 mg/kg AM251 did not affect any of these responses. SR-141716 also elicited an acute reversal of the hypotension and decreased contractility when administered after the response to LPS had fully developed. The LPS-induced hypotension and its inhibition by SR-141716 were similar in pentobarbital-anesthetized wild-type, CB1(-/-), and CB1(-/-)/CB2(-/-) mice. We conclude that SR-141716 inhibits the acute hemodynamic effects of LPS by interacting with a cardiac receptor distinct from CB1 or CB2 that mediates negative inotropy and may be activated by anandamide or a related endocannabinoid released during endotoxemia.
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http://dx.doi.org/10.1152/ajpheart.00184.2004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2543126PMC
August 2004

Lipopolysaccharide induces anandamide synthesis in macrophages via CD14/MAPK/phosphoinositide 3-kinase/NF-kappaB independently of platelet-activating factor.

J Biol Chem 2003 Nov 29;278(45):45034-9. Epub 2003 Aug 29.

Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA.

Macrophage-derived endocannabinoids have been implicated in endotoxin (lipopolysaccharide (LPS))-induced hypotension, but the endocannabinoid involved and the mechanism of its regulation by LPS are unknown. In RAW264.7 mouse macrophages, LPS (10 ng/ml) increases anandamide (AEA) levels >10-fold via CD14-, NF-kappaB-, and p44/42-dependent, platelet-activating factor-independent activation of the AEA biosynthetic enzymes, N-acyltransferase and phospholipase D. LPS also induces the AEA-degrading enzyme fatty acid amidohydrolase (FAAH), and inhibition of FAAH activity potentiates, whereas actinomycin D or cycloheximide blocks the LPS-induced increase in AEA levels and N-acyltransferase and phospholipase D activities. In contrast, cellular levels of the endocannabinoid 2-arachidonoylglycerol (2-AG) are unaffected by LPS but increased by platelet-activating factor. LPS similarly induces AEA, but not 2-AG, in mouse peritoneal macrophages where basal AEA levels are higher, and the LPS-stimulated increase in AEA is potentiated in cells from FAAH-/- as compared with FAAH+/+ mice. Intravenous administration of 107 LPS-treated mouse macrophages to anesthetized rats elicits hypotension, which is much greater in response to FAAH-/- than FAAH+/+ cells and is susceptible to inhibition by SR141716, a cannabinoid CB1 receptor antagonist. We conclude that AEA and 2-AG synthesis are differentially regulated in macrophages, and AEA rather than 2-AG is a major contributor to LPS-induced hypotension.
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http://dx.doi.org/10.1074/jbc.M306062200DOI Listing
November 2003

CB(1) cannabinoid receptor antagonism promotes remodeling and cannabinoid treatment prevents endothelial dysfunction and hypotension in rats with myocardial infarction.

Br J Pharmacol 2003 Apr;138(7):1251-8

Department of Medicine and Cardiology, University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany.

1. To study the long-term effects of altered cannabinoid receptor activity on myocardial and vascular function, Wistar rats were treated with the selective CB(1) antagonist AM-251 (0.5 mg kg(-1) d(-1)), the potent synthetic cannabinoid HU-210 (50 micro g kg(-1) d(-1)) or vehicle for 12 weeks after coronary artery ligation or sham operation. 2. AM-251 further reduced the pressure-generating capacity, shifted the pressure volume curve to the right (P<0.05) and increased the left-ventricular operating volume (AM-251: 930+/-40 micro l vs control: 820+/-40 micro l vs HU-210: 790+/-50 micro l; P<0.05) in rats with large myocardial infarction (MI). 3. Left-ventricular CB(1) immunoactivity in rats 12 weeks after large MI was unaltered as compared with noninfarcted hearts. 4. Cannabinoid receptor activation through HU-210, a cannabinoid that alters cardiovascular parameters via CB(1) receptors, increased the left-ventricular end-diastolic pressure (LVEDP, P<0.05). However, it prevented the drop in left-ventricular systolic pressure (HU-210: 142+/-5 mm Hg; P<0.05 vs control: 124+/-3 mm Hg; and P<0.001 vs AM-251: 114+/-3 mm Hg) and prevented endothelial dysfunction (ED) in aortic rings of rats with large MI (P<0.05). 5. Compared with AM-251, HU-210 prevented the decline in the maximal rate of rise of left-ventricular pressure and the maximum pressure-generating ability (P<0.05). In rats with small MI, HU-210 increased cardiac index (P<0.01) and lowered the total peripheral resistance (P<0.05). 6. The study shows that during the development of congestive heart failure post-large MI, cannabinoid treatment increases LVEDP and prevents hypotension and ED. Presumed CB(1) antagonism promotes remodeling despite unchanged myocardial CB(1) expression.
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http://dx.doi.org/10.1038/sj.bjp.0705156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1573770PMC
April 2003

Cannabinoids acting on CB1 receptors decrease contractile performance in human atrial muscle.

J Cardiovasc Pharmacol 2003 Apr;41(4):657-64

Medizinische Klinik, Abteilung für Herz und Thoraxchirurgie der Universität Würzburg, Würzburg, Germany.

Cannabinoids elicit hypotension mainly via activated CB(1) receptors and show complex cardiovascular actions. Effects on human heart muscle have not been studied yet. Isolated human atrial heart muscle preparations were stimulated by electrical field with 1 Hz to contract isometrically at optimal length and were challenged with the endogenous cannabinoid arachidonyl ethanolamide (anandamide), the metabolically stable analogue R-methanandamide, and the potent synthetic CB(1) receptor agonist HU-210. Anandamide dose-dependently decreased systolic force (82.2 +/- 4.8% and 60.8 +/- 6.8% of maximal systolic force for 0.1 and 1 microM, respectively, P < 0.05). The selective CB(1) receptor antagonist AM-251 (1 microM, P < 0.05), but not the CB(2) receptor antagonist, AM-630 (1 microM), the nitric oxide synthase inhibitor N omega-nitro-l-arginine methyl ester (l-NAME) (500 microM), or the cyclooxygenase inhibitor indomethacin (100 microM), prevented the effect. Contrary to indomethacin, l-NAME alone showed negative inotropic effects (72.1 +/- 3.54%, P < 0.001). The R-methanandamide (1 microM: 50.4 +/- 3.5%, P < 0.001) and HU-210 (1 microM: 60.1 +/- 3.8%, P < 0.001) had similar negative inotropic effects. The existence of CB(1) receptors on heart muscle was verified using Western blot analysis and immunofluorescence staining. The conclusion is that anandamide, R-methanandamide, and HU-210 decrease contractile performance in human atrial muscle via CB(1) receptors.
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http://dx.doi.org/10.1097/00005344-200304000-00020DOI Listing
April 2003