Binding characteristics of brivaracetam, a selective, high affinity SV2A ligand in rat, mouse and human brain: relationship to anti-convulsant properties.

Brivaracetam is a novel synaptic vesicle protein 2A (SV2A) ligand reported to be 10 fold more potent than levetiracetam in animal models of epilepsy. This study reports the binding profile of brivaracetam in the brain of several species in relation to its anticonvulsant properties. The affinity, kinetics and selectivity of brivaracetam and its tritiated form [(3)H]ucb 34714 have been determined by in vitro binding experiments in rat, human and mouse brain and on recombinant human SV2A.

Binding characteristics of levetiracetam to synaptic vesicle protein 2A (SV2A) in human brain and in CHO cells expressing the human recombinant protein.

A specific binding site for the antiepileptic drug levetiracetam (2S-(oxo-1-pyrrolidinyl)butanamide, Keppra) in rat brain, referred to as the levetiracetam binding site, was discovered several years ago. More recently, this binding site has been identified as the synaptic vesicle protein 2A (SV2A), a protein present in synaptic vesicles [Lynch, B., Lambeng, N.

Characterization of [(3)H]ucb 30889 binding to synaptic vesicle protein 2A in the rat spinal cord.

The novel antiepileptic drug levetiracetam ((2S-(2-oxo-1-pyrrolidinyl)butanamide, KEPPRA possesses a specific binding site in brain, which has very recently been identified as the synaptic vesicle protein SV 2 A. The aim of this study was to evaluate the presence of a levetiracetam binding site in the spinal cord and compare its properties to that in rat brain. We used [(3)H]ucb 30889 ((2S)-2-[4-(3-azidophenyl)-2-oxopyrrolidin-1-yl]butanamide), a levetiracetam analogue, to perform binding assays, photoaffinity labelling and autoradiography experiments, and revealed the presence of SV 2 A by Western-blot analysis.

Caspase activation precedes PTP opening in TNF-alpha-induced apoptosis in L929 cells.

In this work, we studied the apoptotic pathway in murine fibrosarcoma cells L929 exposed to tumor necrosis factor alpha (TNF-alpha). DNA fragmentation, activation of caspases, cytochrome c release and poly (ADP-ribose) polymerase cleavage were demonstrated. We showed that the proapoptotic proteins Bid and Bax as well as caspase 8 are involved in the initiation of this apoptotic pathway triggered by TNF-alpha.

In vitro properties of 5-(benzylsulfonyl)-4-bromo-2-methyl-3(2H)-pyridazinone: a novel permeability transition pore inhibitor.

Despite the increasing implication of the permeability transition pore (PTP) in the pathophysiology of neurodegenerative diseases, few selective PTP inhibitors have been reported so far. Here, we evaluate the pharmacological properties of a novel PTP inhibitor, BBMP (5-(benzylsulfonyl)-4-bromo-2-methyl-3(2H)-pyridazinone). This drug was discovered from the screening of a compound library against the PTP using a functional assay with isolated mitochondria.

[3H]linopirdine binding to rat brain membranes is not relevant for M-channel interaction.

Linopirdine was developed as a cognitive enhancing molecule and demonstrated to specifically block the potassium current generated by the brain specific KCNQ2-KCNQ3 proteins (M-channel). In this study we investigated the relevance of [(3)H]linopirdine binding in rat brain extracts to the interaction with the M-channel proteins. Our results confirm the presence of a high affinity site for [(3)H]linopirdine in rat brain tissues (KD = 10 nM) but we also identified a high affinity binding site for [(3)H]linopirdine in rat liver tissues (KD = 9 nM).

The synaptic vesicle protein SV2A is the binding site for the antiepileptic drug levetiracetam.

Here, we show that the synaptic vesicle protein SV2A is the brain binding site of levetiracetam (LEV), a new antiepileptic drug with a unique activity profile in animal models of seizure and epilepsy. The LEV-binding site is enriched in synaptic vesicles, and photoaffinity labeling of purified synaptic vesicles confirms that it has an apparent molecular mass of approximately 90 kDa. Brain membranes and purified synaptic vesicles from mice lacking SV2A do not bind a tritiated LEV derivative, indicating that SV2A is necessary for LEV binding.

Mitochondria permeability transition-dependent tert-butyl hydroperoxide-induced apoptosis in hepatoma HepG2 cells.

Tert-butyl hydroperoxide (t-BHP) has been demonstrated to induce apoptosis in hepatoma cell line HepG2, but poor data were available on the signaling pathway initiated by t-BHP. In this work, we studied in details the apoptotic pathways induced in HepG2 cells by t-BHP. DNA fragmentation, activation of caspases and cytochrome c release were demonstrated.

Comparative study of membrane potential-sensitive fluorescent probes and their use in ion channel screening assays.

In this study, the authors compared and evaluated 4 membrane potential probes in the same cellular assay: the oxonol dye DiBAC(4)(3), the FLIPR membrane potential (FMP) dye (Molecular Devices), and 2 novel fluorescence resonance energy transfer (FRET) dye systems from PanVera [CC2-DMPE/DiSBAC(2)(3)] and Axiom [DiSBAC(1)(3)/DiSBAC(1)(5)]. The kinetic parameters of each membrane probe were investigated in RBL-2H3 cells expressing an endogenous inward rectifier potassium channel (IRK1). The FMP dye presented the highest signal over background ratio whereas the FRET dyes from PanVera gave the fastest response.

Localization and photoaffinity labelling of the levetiracetam binding site in rat brain and certain cell lines.

Levetiracetam (2S-(2-oxo-1-pyrrolidinyl)butanamide, KEPPRA, a novel antiepileptic drug, has been shown to bind to a specific binding site located in the brain (Eur. J. Pharmacol.

Binding characteristics of [3H]ucb 30889 to levetiracetam binding sites in rat brain.

Levetiracetam (2S-(2-oxo-1-pyrrolidinyl)butanamide, KEPPRA, a novel antiepileptic drug, has been shown to bind to a specific binding site located in brain (levetiracetam binding site [Eur. J. Pharmacol.