Common toxin components among different Tityus species in the Amazon region may lead to a common therapeutic strategy

 

Scorpionism is a major problem in many parts of the world, and for the Amazon Region in South America several Tityus C. L. Koch, 1836 species (Buthidae) are known to cause severe morbidity or even deaths. The problem is that there is no effective antivenom currently available in this region.

Identifying the different toxin components of the venom of different Tityus species may lead to the development of new therapeutics.Yan Kalapothakis and co-workers have recently published a study analysing the venom of the medical important species Tityus cisandinus Lourenço & Ythier, 2017 and comparing it to the venom of another medical imprtant species T. obscurus (Gervais, 1843).

Interestingly, they found a high similarity between T. cisandinus and T. obscurus venoms. This is important knowledge that can be used to create a "common therapeutic strategy (i.e production of a region-specific antivenom) to tackle the increasing burden of scorpionism in Amazonia" [Adolfo Borges, personal communication].

Abstract:
Tityus cisandinus, a neglected medically important scorpion in Ecuadorian and Peruvian Amazonia, belongs to a complex of species related to the eastern Amazon endemic Tityus obscurus, spanning a distribution of ca. 4000 km. Despite high morbidity and mortality rates, no effective scorpion antivenom is currently available in the Amazon region. Knowledge of the structural/functional relationships between T. cisandinus venom components and those from related Amazonian species is crucial for designing region-specific therapeutic antivenoms. In this work, we carried out the first venom gland transcriptomic study of an Amazonian scorpion outside Brazil, T. cisandinus. We also fingerprinted its total venom through MALDI-TOF MS, which supported our transcriptomic findings. We identified and calculated the expression level of 94 components: 60 toxins, 25 metalloproteases, five disulfide isomerases, three amidating enzymes, one hyaluronidase, and also uncovered transcripts encoding novel lipolytic beta subunits produced by New World buthid scorpions. This study demonstrates the high similarity between T. cisandinus and T. obscurus venoms, reinforcing the existence of a neglected complex of genetically and toxinologically related Amazonian scorpions of medical importance. Finally, we demonstrated the low recognition of currently available therapeutic sera against T. cisandinus and T. obscurus venoms, and concluded that these should be improved to protect against envenomation by Amazonian Tityus spp.

Reference:
Kalapothakis Y, Miranda K, Molina DAM, Conceição I, Larangote D, Op den Camp HJM, et al. An overview of Tityus cisandinus scorpion venom: Transcriptome and mass fingerprinting reveal conserved toxin homologs across the Amazon region and novel lipolytic components. Int J Biol Macromol. 2022. [Subscritpion required for full text]

Thanks to Adolfo Borges for informing me about this article!