Haplopelma hainanum venom induces inflammatory skin lesions.

Zhili Deng,Yiya Zhang,San Xu,Yaling Wang,Ji Li,Lei Zhou,Wei Shi

doi:10.7717/peerj.8264

Abstract

The Haplopelma hainanum is a species of theraphosid spider from China. Its large size and charming appearance make this species a popular pet. According to a previous study, theraphosid spider bites can induce pain, erythema, and edema in humans and can present more severely in domestic animals. The pathological consequences of envenomation by H. hainanum remain unclear. In this study, we investigated the effects and mechanisms of H. hainanum envenomation in mice. We showed that the venom induced slight swelling, intense inflammatory response, and increased the microvascular density in mice skin. Moreover, we found that 50 µg/ml of the spider’s venom induced IL-1β expression in both HaCaT cells and fibroblast cells, but repressed CXCL10 expression in fibroblasts. The venom significantly induced cell senescence and repressed cell proliferation and migration in both HaCaT cells and fibroblast cells. Finally, we examined the expression of Nav channel in HaCaT and fibroblast cells and found that H. hainanum venom effectively inhibited Na+ currents in HaCaT cells. Our study calls for further investigation of the pathological consequences and potential mechanisms of H. hainanum envenomation. This information might assist in the development of suitable therapy.

Highlights

IntroductionSpiders are one of the oldest and most abundant venomous animals, with a fossil history spanning more than 300 million years and over 40,000 species (Deng et al, 2016)
We examined the pathological alterations induced by H. hainanum venom in mice, and discovered the mechanism that potentially contributes to lesion development in HaCaT and fibroblast cells
The number of MHCII+ cells increased at the 10 μg per site and 30 μg per site where venom was applied (Figs. 1M–1R). These results indicate that H. hainanum venom induces inflammatory cell infiltration in mice

Summary

Introduction

Spiders are one of the oldest and most abundant venomous animals, with a fossil history spanning more than 300 million years and over 40,000 species (Deng et al, 2016). Approximately 10,000 spider bites are reported in Brazil and nearly 3,000 bites in America (Braitberg & Segal, 2009). The venom of most spiders causes only minor discomfort including edema, hemorrhage, and sometimes subsequent ulceration (Dunbar et al, 2018; Isbister & Fan, 2011). Spider envenomation can cause severe reactions such as systemic loxoscelism, which can progress to acute renal failure and even death (Manzoni-de Almeida et al, 2018; Okamoto et al, 2017). Most studies on spider envenomation focus on one of the most venomous spiders, the Loxosceles.

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