The underlying mechanism of scorpion venom peptide BmK AS in reducing epilepsy seizures: mediated through dual modulation of Nav1.6 and the inflammasome pathway

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  The underlying mechanism of scorpion venom peptide BmK AS in reducing epilepsy seizures: mediated through dual modulation of Nav1.6 and the inflammasome pathway Abstract Introduction:  Voltage-gated sodium channel (VGSC) dysregulation, particularly of the Nav1.6 subtype, is a core mechanism underlying epileptogenesis and its associated neuropsychiatric comorbidities. The scorpion venom peptide BmK AS has demonstrated anticonvulsant potential, but its efficacy in chronic epilepsy and the precise mechanisms of action remain undefined. Methods:  Here, we show that BmK AS exerts robust anti-epileptic and neuroprotective effects through converging mechanisms. In a kainic acid-induced mouse model, BmK AS treatment reduced mortality and seizure parameters. Electrophysiological studies assessed BmK AS modulation of VGSC subtypes. The functional relevance of Nav1.6 targeting was confirmed by the loss of BmK AS’s anti-seizure efficacy upon its pharmacological blockade in a PTZ-in...

The Microbiome of an Invasive Spider: Reduced Bacterial Richness, but no Indication of Microbial-Mediated Dispersal Behaviour

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Abstract

Mermessus trilobatus, an invasive North American linyphiid spider, has expanded its invasion range up to 1400 km in Europe, accelerating its dispersal speed in less than 40 years. The high heritability of dispersal behaviour and the spatial sorting of high and low dispersers indicate a genetic basis of dispersal behaviour. However, microbial endosymbionts can moderate dispersal behaviour in related species (Rickettsia in Erigone atra). Hence, dispersal behaviour in M. trilobatus might also be dictated by the activity of dispersal-mediating endosymbionts. Here, we investigated the microbiome of invasive M. trilobatus spiders extracted from (1) high- and low-dispersive individuals and (2) spiders originating from locations close to the edge and core of the expansion. We examine the microbiomes for the presence of potential dispersal- and reproduction-mediating bacterial strains and compare the microbial assemblages of spiders based on their dispersal behaviour and locations of origin. The composition of microbial assemblages was similar among spiders of different geographic origins and dispersal behaviour. However, microbial richness was lower in high- than in low-dispersive individuals. Surprisingly, none of the known dispersal- or reproduction-altering endosymbionts of arthropods was identified in any tested spider. This contrasts with published results from North America, where M. trilobatus is a known host of Rickettsia and Wolbachia. Thus, the invasive European population appears to have lost its associated endosymbionts. As endosymbionts can reduce spider mobility, it is possible that their absence facilitates the spread of the invasive spider population. The absence of endosymbionts among the analysed individuals substantiates the role of genetic mechanisms behind the variable dispersal behaviour of invasive M. trilobatus in Europe. 

Nariman, N., Entling, M.H., Krehenwinkel, H. et al. The Microbiome of an Invasive Spider: Reduced Bacterial Richness, but no Indication of Microbial-Mediated Dispersal Behaviour. Microb Ecol 88, 70 (2025). https://doi.org/10.1007/s00248-025-02565-6