Hunting ecology predicts eye arrangements in the modular visual system of spiders

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  Hunting ecology predicts eye arrangements in the modular visual system of spiders Summary Vision is one of the most important senses used by animals and contributes to fundamental behaviors, including foraging, navigation, and mate detection and selection. 1 Although much is known about how eye position and orientation correlate to ecology in the context of binocularity, 2 animals with multipartite visual systems (more than two eyes) remain comparatively neglected. Spiders are highly successful predators that occupy a range of ecological niches and usually possess eight eyes. Here, we use three-dimensional geometric morphometrics and evolutionary modeling to test whether eye positions, orientations, and interocular angles correlate with hunting strategies in 52 species across the spider phylogeny. We demonstrate that eye configurations diversified from an ancestral medial cluster, as seen in modern trapdoor spiders, to a halo-like configuration in orb-weavers, and to the fronta...

Proteasome-driven modulation of immune and oxidative pathways during scorpion envenomation pathogenesis

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Proteasome-driven modulation of immune and oxidative pathways during scorpion envenomation pathogenesis

Abstract

Background:  Scorpion venom contains a variety of toxin molecules that are the drivers of inflammation and oxidative stress, leading to significant tissue damage. While several mechanisms underlying these responses have been studied, the involvement of the proteasome complex - a key regulator of inflammation - remains poorly understood. This study explored the role of the proteasome in modulating inflammatory and oxidative responses to envenomation by Androctonus australis hector venom.

Methods:  Mice were pretreated intraperitoneally with bortezomib, a proteasome inhibitor, at low (0.05 mg/kg), medium (0.25 mg/kg), or high (0.5 mg/kg) doses, 30 minutes prior to sublethal venom administration (0.5 mg/kg, subcutaneous). Twenty-four hours after venom administration, animals were euthanized, blood and organs were collected to evaluate vascular permeability (via Evans blue dye extravasation), the extent of inflammatory cell infiltration (myeloperoxidase and eosinophil peroxidase enzymatic activities), and oxidative/nitrosative stress markers (nitric oxide, hydrogen peroxide, malondialdehyde, catalase activity, and glutathione). Histopathological examinations were performed to identify structural alterations, such as edema, hemorrhage, and cellular infiltration. Biochemical parameters reflecting organ function, including serum levels of CPK, LDH, ALT, ALP, urea, and creatinine, were also measured to assess the degree of systemic damage.

Results:  Our findings revealed a dose-dependent immune-modulatory role of the proteasome system. A medium dose of bortezomib reduced inflammatory and oxidative stress markers, such as vascular permeability, eosinophil peroxidase, neutrophil peroxidase, nitric oxide, and malondialdehyde in renal tissue, suggesting a reduction in local inflammation and oxidative damage. In contrast, a higher dose showed pronounced preventive effects in cardiopulmonary and hepatic tissues, significantly reducing inflammatory mediators and oxidative markers, restoring antioxidant enzyme activity (catalase) and glutathione, as well as, improving tissue structure and organ function.

Conclusion:  These findings underscore the proteasome involvement in inflammatory regulation, likely through modulation of vascular permeability, immune cell activation, and oxidative stress, making it a key target in scorpion envenomation.


Megdad-Lamraoui, A., Adi-Bessalem, S., Daachi, F., & Laraba-Djebari, F.. (2025). Proteasome-driven modulation of immune and oxidative pathways during scorpion envenomation pathogenesis. Journal of Venomous Animals and Toxins Including Tropical Diseases, 31, e20250007. https://doi.org/10.1590/1678-9199-JVATITD-2025-0007