Effects of the paratemnus elongatus pseudoscorpion venom in the uptake and binding of the L‐glutamate and GABA from rat cerebral cortex

Abstract

L-Glu is the most important and widespread excitatory neurotransmitter of the vertebrates. Four types of receptors for L-glu have been described. This neurotransmitter modulates several neuronal processes, and its dysfunction causes chronic and acute diseases. L-Glu action is terminated by five distinct transporters. Antagonists for these receptors and modulators of these transporters have anticonvulsant and neuroprotective potentials, as observed with the acylpoliamines and peptides isolated from spiders, solitary and social wasp venoms. On the other hand, the major inhibitory neurotransmitter in mammalian nervous tissue is the GABA. Drugs that enhance GABA neurotransmission comprise effective approaches to protecting the brain against neuronal injury. Is this study, we demonstrate for the first time the inhibition of the [3H]L-glu binding to its specific sites in synaptosomal membranes from rat cerebral cortex, produced by 0.027 U of Paratemnus elongatus venom (EC50). The venom of P. elongatus changes Km and Vmax into the high affinity uptake of the L-glu and decreases Km and Vmax into the parameters of the GABA uptake from rat synaptosomes. This leads us to speculate on the possible presence of selective and specific compounds in this venom that act in L-glu and GABA dynamics, and therefore, that can serve as tools and new drug models for understanding these neurotransmissions.

Transcriptomic Analysis of Pseudoscorpion Venom Reveals a Unique Cocktail Dominated by Enzymes and Protease Inhibitors

“…However, its similarity to other agatoxins, a family of peptides including low mass molecular toxins with affinity to the sodium or calcium ion channels [ 40 ], suggest they might share similar functions. The only previous study on the effects of the crude venom of pseudoscorpion suggested the presence of putative neurotoxins of peptidic and nonpeptidic nature [ 11 ]. Whether the three groups found in pseudoscorpion venom are the culprit for neurotoxicity in rat brain is uncertain, because studies in spider venom have also shown the presence of polyamines targeting ionotropic glutamate receptors (e.g., [ 41 , 42 ]).…”

“…Surprisingly, and in contrast to the remaining venomous arachnid groups, the composition of pseudoscorpion venom remains unknown. Santos et al [ 11 ] studied the effect of the crude venom from Paratemnoides elongatus on a rat cerebral cortex. Their findings were suggestive of the presence of selective compounds (e.g., neurotoxins) acting in l -glu and GABA dynamics, but no specific compounds were reported.…”

De novo assembly and characterisation of the transcriptome of the Beringian pseudoscorpion

“…Pseudoscorpions (Arachnida: Pseudoscorpiones) are small (2-8 mm) predatory microarthropods that reach their peak species diversity in the tropics (Harvey 2007). Pseudoscorpions hunt other small arthropods, and those in the suborder Iocheirata paralyse their prey with venom from glands in their chelae (Dos Santos and Coutinho-Netto 2006). Wyochernes asiaticus (Arachnida: Pseudoscorpiones: Chernetidae) is the northernmost pseudoscorpion (Buddle 2015), living in Beringia, the region of what is now the Yukon Territory, Canada, Alaska, the United States of America, and parts of far eastern Russia that remained unglaciated in the last glacial maximum (Hopkins 1982).…”

Quo Vadis Venomics? A Roadmap to Neglected Venomous Invertebrates

“…We are aware of only a single experimental study into the effects of pseudoscorpion venom. This study showed that the crude venom of Paratemnoides elongatus affects the uptake and binding of neurotransmitter in rat brain preparations [ 139 ]. However, nothing at all is known about the composition of pseudoscorpion venom.…”