ABSTRACT
Mutations in codon 132 of isocitrate dehydrogenase (IDH) 1 are frequent in diffuse glioma, acute myeloid leukemia, chondrosarcoma and intrahepatic cholangiocarcinoma. These mutations result in a neomorphic enzyme specificity which leads to a dramatic increase of intracellular D-2-hydroxyglutarate (2-HG) in tumor cells. Therefore, mutant IDH1 protein is a highly attractive target for inhibitory drugs. Here, we describe the development and properties of BAY 1436032, a pan-inhibitor of IDH1 protein with different codon 132 mutations. BAY 1436032 strongly reduces 2-HG levels in cells carrying IDH1-R132H, -R132C, -R132G, -R132S and -R132L mutations. Cells not carrying IDH mutations were unaffected. BAY 1436032 did not exhibit toxicity in vitro or in vivo. The pharmacokinetic properties of BAY 1436032 allow for oral administration. In two independent experiments, BAY 1436032 has been shown to significantly prolong survival of mice intracerebrally transplanted with human astrocytoma carrying the IDH1R132H mutation. In conclusion, we developed a pan-inhibitor targeting tumors with different IDH1R132 mutations.
Subject(s)
Aniline Compounds/pharmacology , Antineoplastic Agents/pharmacology , Astrocytoma/drug therapy , Benzimidazoles/pharmacology , Brain Neoplasms/drug therapy , Isocitrate Dehydrogenase/antagonists & inhibitors , Isocitrate Dehydrogenase/genetics , Aniline Compounds/chemistry , Aniline Compounds/pharmacokinetics , Aniline Compounds/toxicity , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/toxicity , Astrocytoma/enzymology , Astrocytoma/genetics , Benzimidazoles/chemistry , Benzimidazoles/pharmacokinetics , Benzimidazoles/toxicity , Brain Neoplasms/enzymology , Brain Neoplasms/genetics , Cell Line, Tumor , Cell Survival/drug effects , Cell Survival/physiology , Colonic Neoplasms/drug therapy , Colonic Neoplasms/enzymology , Colonic Neoplasms/genetics , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/toxicity , Escherichia coli , Female , Glutarates/metabolism , HEK293 Cells , Humans , Isocitrate Dehydrogenase/metabolism , Mice, Inbred BALB C , Mice, Nude , Mutation , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sarcoma/drug therapy , Sarcoma/enzymology , Sarcoma/genetics , Sf9 Cells , Xenograft Model Antitumor AssaysABSTRACT
The cholinergic system is critically involved in the modulation of cognitive functions, including learning and memory. Acetylcholine acts through muscarinic (mAChRs) and nicotinic receptors (nAChRs), which are both abundantly expressed in the hippocampus. Previous evidence indicates that choline, the precursor and degradation product of Acetylcholine, can itself activate nAChRs and thereby affects intrinsic and synaptic neuronal functions. Here, we asked whether the cellular actions of choline directly affect hippocampal network activity. Using mouse hippocampal slices we found that choline efficiently suppresses spontaneously occurring sharp wave-ripple complexes (SPW-R) and can induce gamma oscillations. In addition, choline reduces synaptic transmission between hippocampal subfields CA3 and CA1. Surprisingly, these effects are mediated by activation of both mAChRs and α7-containing nAChRs. Most nicotinic effects became only apparent after local, fast application of choline, indicating rapid desensitization kinetics of nAChRs. Effects were still present following block of choline uptake and are, therefore, likely because of direct actions of choline at the respective receptors. Together, choline turns out to be a potent regulator of patterned network activity within the hippocampus. These actions may be of importance for understanding state transitions in normal and pathologically altered neuronal networks. In this study we asked whether choline, the precursor and degradation product of acetylcholine, directly affects hippocampal network activity. Using mouse hippocampal slices we found that choline efficiently suppresses spontaneously occurring sharp wave-ripple complexes (SPW-R). In addition, choline reduces synaptic transmission between hippocampal subfields. These effects are mediated by direct activation of muscarinic as well as nicotinic cholinergic pathways. Together, choline turns out to be a potent regulator of patterned activity within hippocampal networks.
Subject(s)
Choline/physiology , Hippocampus/physiology , Action Potentials/physiology , Animals , Autonomic Pathways/drug effects , CA1 Region, Hippocampal/drug effects , CA3 Region, Hippocampal/drug effects , Data Interpretation, Statistical , Electroencephalography/drug effects , Electrophysiological Phenomena/drug effects , Evoked Potentials/drug effects , Hippocampus/drug effects , In Vitro Techniques , Male , Mice , Mice, Inbred C57BL , Nerve Net/drug effects , Nerve Net/physiology , Parasympathetic Nervous System/drug effects , Receptors, Muscarinic/drug effects , Receptors, Nicotinic/drug effects , Synaptic Transmission/drug effectsABSTRACT
Acute pulmonary arterial hypertension in acute lung injury aggravates the clinical course and complicates treatment. Increased release and turnover of endogenous endothelin-1 is known to be a major determinant in the pathophysiology of pulmonary arterial hypertension of various etiologies. We tested whether intravenous tezosentan, a dual endothelin receptor antagonist, reduced pulmonary artery pressure in a pig model of acute lung injury induced by meconium aspiration. Acute pulmonary arterial hypertension was induced in 12 anesthetized and instrumented pigs by instillation of human pooled meconium in a 20% solution. Hemodynamic and gas exchange parameters were recorded every 30 min. Six animals received tezosentan 5 mg/kg after 0 and 90 min; six animals served as controls. Tezosentan led to a decrease of mean pulmonary artery pressure (PAP) from 33.4 +/- 4.0 mm Hg to 24.7 +/- 2.1 mm Hg and pulmonary vascular resistance (PVR) from 7.8 +/- 1.4 mm Hg.L(-1).min.m2 to 5.2 +/- 0.7 mm Hg.L(-1).min.m2. All animals treated with tezosentan survived, whereas in the control group four out of six animals died. Tezosentan improved survival and decreased pulmonary artery pressure in a porcine model of acute pulmonary arterial hypertension after meconium aspiration. Tezosentan has the potential for effective pharmacological treatment of pulmonary arterial hypertension following acute lung injury.