Efficacy of certain quinolines as pharmacological antagonists in botulinum neurotoxin poisoning

doi:10.1016/S0041-0101(96)00147-X

Toxicon

Volume 35, Issue 3, March 1997, Pages 433-445

https://doi.org/10.1016/S0041-0101(96)00147-X Get rights and content

Abstract

Various 4- and 8-aminoquinolines, which are effective antimalarial agents, were examined as potential pretreatment compounds for prolongation of the time to 50% block of nerve-elicited muscle twitches in isolated mouse diaphragms exposed to botulinum type A neurotoxin. The 4-aminoquinolines (chloroquine, amodiaquine) and quinacrine, an acridine derivative similar to chloroquine, prolonged the time required for botulinum type A neurotoxin to block neuromuscular transmission by more than 3-fold; 8-aminoquinolines (primaquine and WR242511) had no antibotulinum type A neurotoxin activity. Pyrimethamine, an antimalarial drug lacking the quinoline ring structure, was also ineffective. Rank order potencies based on equimolar effective concentrations for the test compounds were quinacrine > amodiaquine > chloroquine > quinine or quinidine. Maximum protection from botulinum type A neurotoxin-induced neuro-muscular block was achieved when muscles were exposed to drug prior to or simultaneously with the toxin. A delay of more than 20 min abolished the protective ability of the antimalarial agents, presumably owing to the release of the toxin from endosomes in quantities sufficient to initiate neuromuscular block. All of the test compounds except quinine and quinidine depressed muscle contractions when concentrations exceeded 20 μM. In addition, amodiaquine at 50 μM induced muscle contracture. A combination of agents at low concentrations that act at different steps of botulinum type A neurotoxin poisoning potentiated the prolongation of time to 50% block in an approximately additive fashion. Thus N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (2 μM) and quinacrine (5 μM), when administered in combination, produced up to a 4-fold increase in time to 50% block. A similar level of protection with quinacrine alone required a 4-fold increase in the aminoquinoline concentration. Although the mechanism of protection by these antimalarial agents is probably through the raising of endosomal pH, the possibility that some of these drugs could also act by inhibiting toxin-induced channel formation cannot be ruled out.

References (28)

T. Binz et al.
Proteolysis of SNAP-25 by types E and A botulinal neurotoxins
J. biol. Chem.
(1994)
S.S. Deshpande et al.
A study of zinc-dependent metalloendopeptidase inhibitors as pharmacological antagonists in botulinum neurotoxin poisoning
Toxicon
(1995)
N. Fujii et al.
A zinc-protease specific domain in botulinum and tetanus neurotoxins
Toxicon
(1992)
H. Kurazono et al.
Minimal essential domains specifying toxicity of the light chains of tetanus toxin and botulinum neurotoxin type A
J. biol. Chem.
(1992)
G. Schiavo et al.
Botulinum neurotoxin serotype F is a zinc endopeptidase specific for VAMP/synaptobrevin
J. biol. Chem.
(1993)
G. Schiavo et al.
Botulinum G neurotoxin cleaves VAMP/synaptobrevin at a single Ala-Ala peptide bond
J. biol. Chem.
(1994)
R.E. Sheridan
Protonophore antagonism of botulinum neurotoxin in mouse muscle
Toxicon
(1996)
R.E. Sheridan et al.
Interactions between heavy metal chelators and botulinum neurotoxins at the mouse neuromuscular junction
Toxicon
(1995)
J.P. Sieb et al.
Effects of the quinoline derivatives quinine, quinidine, and chloroquine on neuromuscular transmission
Brain Res.
(1996)
L.L. Simpson
Peripheral actions of the botulinum toxins

R.W. Wannemacher et al.

Efficacy of zinc chelator, N′, N′, N′ ,N′-tetrakis(2-pyridyl-methyl)ethylene-diamine (TPEN), against botulinum type-A or B neurotoxin in mice

Toxicon

(1995)

N. Bakry et al.

Lectins from Triticum vulgaris and Limax flavus are universal antagonists of botulinum neurotoxin and tetanus toxin

J. Pharmac. exp. Ther.

(1991)

J.D. Black et al.

Interaction of [¹²⁵I]-labelled botulinum neurotoxin with nerve terminals. II. Autoradiographic evidence for its uptake into motor nerve by acceptor-mediated endocytosis

J. Cell Biol.

(1986)

J. Blasi et al.

Botulinum neurotoxin A selectively cleaves the synaptic protein SNAP-25

Nature, Lond.

(1993)

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The translocation of the Lc to the cytosol occurs following a conformational change that is induced by acidification of the endosome (Cai et al., 2006b; Hoch et al., 1985). Drugs that inhibit endosome acidification, such as bafilomycin A1, are antagonists of BoNT intoxication (Deshpande et al., 1997; Simpson, 1983; Simpson et al., 1994). Once in the cytosol, the different BoNT Lcs cleave and inactivate their SNARE protein substrates leading to intoxication.
Botulinum neurotoxin (BoNT) heavy chain (Hc) facilitates receptor-mediated endocytosis into neuronal cells and transport of the light chain (Lc) protease to the cytosol where neurotransmission is inhibited as a result of SNARE protein cleavage. Here we show that the role of BoNT Hc in cell intoxication can be replaced by commercial lipid-based and polycationic polymer DNA transfection reagents. BoNT “transduction” by these reagents permits efficient intoxication of neuronal cells as well as some non-neuronal cell lines normally refractory to BoNT. Surprisingly, the reagents facilitate delivery of recombinant BoNT Lc protease to the cytosol of both neuronal and non-neuronal cells in the absence of BoNT Hc, and with sensitivities approaching that of BoNT holotoxin. Transduction of BoNT, as with natural intoxication, is inhibited by bafilomycin A1, methylamine and ammonium chloride indicating that both pathways require endosome acidification. DNA transfection reagents facilitate intoxication by holotoxins, or isolated Lc proteases, of all three BoNT serotypes tested (A, B, E). These results suggest that lipid and cationic polymer transfection reagents facilitate cytosolic delivery of BoNT holotoxins and isolated Lc proteases by an endosomal uptake pathway.
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In the earlier work, it was hypothesized that these compounds delayed paralysis by interfering with toxin translocation into the nerve cytoplasm and therefore they were not tested for specific inhibition of BoNT/A LC protease activity. The percent inhibition of BoNT/A LC that we observed for these drugs was not equivalent to the level of protection that they afforded against muscle paralysis in the previous studies [17,18]. For example, quinacrine, which we report to inhibit BoNT/A LC protease activity by 30% at 50 μM (0.2 mM substrate), was found, in an earlier study [17], to delay the time to 50% muscle paralysis by at least 30% (over control) at 3.3 μM [17].
Botulinum neurotoxins (BoNTs) are among the most lethal biological substances to have been weaponized and are listed as biodefense category A agents. Currently, no small molecule (non-peptidic) therapeutics exist to counter this threat; hence, identifying and developing compounds that inhibit BoNTs is a high priority. In the present study, a high-throughput assay was used to identify small molecules that inhibit the metalloprotease activity of BoNT serotype A light chain (BoNT/A LC). All inhibitors were further verified using a HPLC-based assay. Conformational analyses of these compounds, in conjunction with molecular docking studies, were used to predict structural features that contribute to inhibitor binding and potency. Based on these results, a common pharmacophore for BoNT/A LC inhibitors is proposed. This is the first study to report small molecules (non-peptidics) that inhibit BoNT/A LC metalloprotease activity in the low μM range.
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Efficacy of certain quinolines as pharmacological antagonists in botulinum neurotoxin poisoning

Abstract

J. biol. Chem.

Toxicon

Toxicon

J. biol. Chem.

J. biol. Chem.

J. biol. Chem.

Toxicon

Toxicon

Brain Res.

Toxicon

Lectins from Triticum vulgaris and Limax flavus are universal antagonists of botulinum neurotoxin and tetanus toxin

J. Pharmac. exp. Ther.

Interaction of [125I]-labelled botulinum neurotoxin with nerve terminals. II. Autoradiographic evidence for its uptake into motor nerve by acceptor-mediated endocytosis

J. Cell Biol.

Botulinum neurotoxin A selectively cleaves the synaptic protein SNAP-25

Nature, Lond.

Interaction of [¹²⁵I]-labelled botulinum neurotoxin with nerve terminals. II. Autoradiographic evidence for its uptake into motor nerve by acceptor-mediated endocytosis