The good, the bad and the ugly: Developing strategies for studying the cell- and tissue-damaging effects of snake venoms

Snakebite envenomation is an important public health issue that has long had tremendous implications for human health and well-being. An estimated 1.8-5.4 million people per year fall victim to snakebites, with mortality rates surpassing 100,000 individuals. Although most life-threatening pathologies from venomous snakebites result from neurotoxic and haemotoxic effects, tissue-damaging activities are a significant cause of life-long disabilities. These morbidities include tissue necrosis, amputations, renal damage and blindness. Despite the fact that venom-induced tissue damage affects over 450,000 people annually, research efforts on this pathology are limited compared to neurotoxicity or haemotoxicity. The research in this work, therefore, focuses on elucidating the mechanisms of venom-induced cell- and tissue damage. The relevance of further research on venom-induced cell- and tissue damage is clarified in Chapter 1. This chapter provides an introduction to venomous snakes, discussing their historical and cultural significance and unique characteristics. The first section of this chapter further discusses the taxonomy of venomous snakes. It characterises the morphology of venom delivery systems, highlighting the variations between the various families of venomous snakes. The same chapter describes the global impact of snakebite envenoming, which affects at least 1.8 million people per year, especially in certain regions in Latin America, sub-Saharan Africa, and Southeast Asia. The main focus of Chapter 1 is on snake venom composition and the diverse pathological effects. It categorises these effects into neurotoxicity, haemotoxicity, and tissue-damaging effects and emphasises venom-induced tissue damage. The next section of this chapter provides an overview of the various assays that exist to study tissue-damaging venoms, both in vivo and in vitro. These include assays focusing on cell viability, membrane degradation, and molecular mechanisms underlying cell damage. The chapter then discusses the relevance of elucidating venom composition and points out why separating venoms into their individual components (i.e., their toxins) is essential. This section further provides an overview of the various LC techniques used to separate venoms into their components and stresses the importance of ‘nanofractionation analytics’ and ‘high-throughput (HT) venomics’. By combining bioactivity profiling and mass spectrometry (MS), the toxins of interest (i.e., the bioactive toxins measured with the bioassay used) can directly be identified from the MS data (i.e., LC-MS and/or toxin proteomics data) that is collected in parallel.