Neurotoxin Merging: A Strategy Deployed by the Venom of the Spider Cupiennius salei to Potentiate Toxicity on Insects

Engineering a wolf spider A-family toxin towards increased antimicrobial activity but low toxicity

Spider-derived peptides with insecticidal, antimicrobial and/or cytolytic activities, also known as spider venom antimicrobial peptides (AMPs), can be found in the venoms of RTA-clade spiders. They show translational potential as therapeutic leads. A set of 52 AMPs has been described in the Chinese wolf spider (Lycosa shansia), and many have been shown to exhibit antibacterial effects. Here we explored the potential to enhance their antimicrobial activity using bioengineering. We generated a panel of artificial derivatives of an A-family peptide and screened their activity against selected microbial pathogens, vertebrate cells and insects. In several cases, we increased the antimicrobial activity of the derivatives while retaining the low cytotoxicity of the parental molecule. Furthermore, we injected the peptides into adult Drosophila suzukii and found no evidence of insecticidal effects, confirming the low levels of toxicity. Our data therefore suggest that spider venom linear peptides naturally defend the venom gland against microbial colonization and can be modified into more potent antimicrobial agents that could help to battle infectious diseases in the future.

Cupiennius spiders (Trechaleidae) from southern Mexico: DNA barcoding, venomics, and biological effect

Background

Members of the genus Cupiennius Simon, 1891 are categorized as wandering spiders and are part of the family Trechaleidae. The genomics and proteomics of Cupiennius spiders from North America remain uncharacterized. The present study explores for the first time molecular data from the endemic species Cupiennius chiapanensis Medina, 2006, and also presents new data for Cupiennius salei (Keyserling, 1878), both collected in southern Mexico.

Methods

In total, 88 Cupiennius specimens were collected from southern Mexico and morphologically identified. DNA was extracted and the mitochondrial COI fragment was amplified. COI sequences were analyzed, and a phylogenetic tree was inferred for species from the Americas. Genetic diversity was analyzed using haplotype networks and gene distances. Venom was obtained from C. chiapanensis and C. salei by electrostimulation. The venom was separated by HPLC, visualized using SDS-PAGE, and quantified for use in toxicity bioassays in mice and insects.

Results

Analysis of COI sequences from C. chiapanensis showed 94% identity with C. salei, while C. salei exhibited 94-97% identity with sequences from Central and South American conspecifics. The venom from C. chiapanensis exhibited toxic activity against crickets. Venoms from C. chiapanensis and C. salei caused death in Anastrepha obliqua flies. Analysis of venom fractions from C. salei and C. chiapanensis revealed molecular masses of a similar size as some previously reported toxins and neurotoxic components. We determined the amino acid sequences of ChiaTx1 and ChiaTx2, toxins that are reported here for the first time and which showed toxicity against mice and insects.

Conclusion

Our work is the first to report COI-based DNA barcoding sequences from southern Mexican Cupiennius spiders. Compounds with toxic activity were identified in venom from both species.

Spider-Venom Peptides: Structure, Bioactivity, Strategy, and Research Applications

Spiders (Araneae), having thrived for over 300 million years, exhibit remarkable diversity, with 47,000 described species and an estimated 150,000 species in existence. Evolving with intricate venom, spiders are nature's skilled predators. While only a small fraction of spiders pose a threat to humans, their venoms contain complex compounds, holding promise as drug leads. Spider venoms primarily serve to immobilize prey, achieved through neurotoxins targeting ion channels. Peptides constitute a major part of these venoms, displaying diverse pharmacological activities, and making them appealing for drug development. Moreover, spider-venom peptides have emerged as valuable tools for exploring human disease mechanisms. This review focuses on the roles of spider-venom peptides in spider survival strategies and their dual significance as pharmaceutical research tools. By integrating recent discoveries, it provides a comprehensive overview of these peptides, their targets, bioactivities, and their relevance in spider survival and medical research.

Transcriptome-based analyses reveal venom diversity in two araneomorph spiders, Psechrus triangulus and Hippasa lycosina

The spiders Psechrus triangulus and Hippasa lycosina are widely distributed in Yunnan Province, China, and are important natural enemies of agricultural pests, yet studies regarding the composition of their venom are lacking. In this study, cDNA libraries were constructed from venom gland tissue of P. triangulus and H. lycosina and used for transcriptomic analysis. From the analysis, 39 and 31 toxin-like sequences were predicted for P. triangulus and H. lycosina, respectively. The predicted neurotoxin sequences were categorized according to cysteine sequence motifs, and the predicted neurotoxin sequences of P. triangulus and H. lycosina could be classified into 9 and 6 toxin families, respectively. In addition, potential acetylcholinesterase, hyaluronidase, and astaxanthin-like metalloproteinases were identified through annotation. In summary, transcriptomic techniques were invaluable in mining the gene expression information from these two spider species to explore the toxin composition of their venom and determine how they differ. Studies of this type provide essential baseline data for studying the evolution and physiological activities of spider toxins and for the potential development of medicinal compounds.

Functional Profiling of the A-Family of Venom Peptides from the Wolf Spider Lycosa shansia

The venoms of spiders from the RTA (retro-lateral tibia apophysis) clade contain diverse short linear peptides (SLPs) that offer a rich source of therapeutic candidates. Many of these peptides have insecticidal, antimicrobial and/or cytolytic activities, but their biological functions are unclear. Here, we explore the bioactivity of all known members of the A-family of SLPs previously identified in the venom of the Chinese wolf spider (Lycosa shansia). Our broad approach included an in silico analysis of physicochemical properties and bioactivity profiling for cytotoxic, antiviral, insecticidal and antibacterial activities. We found that most members of the A-family can form α-helices and resemble the antibacterial peptides found in frog poison. The peptides we tested showed no cytotoxic, antiviral or insecticidal activities but were able to reduce the growth of bacteria, including clinically relevant strains of Staphylococcus epidermidis and Listeria monocytogenes. The absence of insecticidal activity may suggest that these peptides have no role in prey capture, but their antibacterial activity may help to defend the venom gland against infection.

Transcriptome analysis of the spider Phonotimpus pennimani reveals novel toxin transcripts

Background

Phonotimpus pennimani (Araneae, Phrurolithidae) is a small-sized (3-5 mm) spider endemic to the Tacaná volcano in Chiapas, Mexico, where it is found in soil litter of cloud forests and coffee plantations. Its venom composition has so far not been investigated, partly because it is not a species of medical significance. However, it does have an important impact on the arthropod populations of its natural habitat.

Methods

Specimens were collected in Southeastern Mexico (Chiapas) and identified taxonomically by morphological characteristics. A partial sequence from the mitochondrial gene coxI was amplified. Sequencing on the Illumina platform of a transcriptome library constructed from 12 adult specimens revealed 25 toxin or toxin-like genes. Transcripts were validated (RT-qPCR) by assessing the differential expression of the toxin-like PpenTox1 transcript and normalising with housekeeping genes.

Results

Analysis of the coxI-gene revealed a similarity to other species of the family Phrurolithidae. Transcriptome analysis also revealed similarity with venom components of species from the families Ctenidae, Lycosidae, and Sicariidae. Expression of the toxin-like PpenTox1 gene was different for each developmental stage (juvenile or adult) and also for both sexes (female or male). Additionally, a partial sequence was obtained for the toxin-like PpenTox1 from DNA.

Conclusion

Data from the amplification of the mitochondrial coxI gene confirmed that P. pennimani belongs to the family Phrurolithidae. New genes and transcripts coding for venom components were identified.

Venom biotechnology: casting light on nature's deadliest weapons using synthetic biology

Venoms are complex chemical arsenals that have evolved independently many times in the animal kingdom. Venoms have attracted the interest of researchers because they are an important innovation that has contributed greatly to the evolutionary success of many animals, and their medical relevance offers significant potential for drug discovery. During the last decade, venom research has been revolutionized by the application of systems biology, giving rise to a novel field known as venomics. More recently, biotechnology has also made an increasing impact in this field. Its methods provide the means to disentangle and study venom systems across all levels of biological organization and, given their tremendous impact on the life sciences, these pivotal tools greatly facilitate the coherent understanding of venom system organization, development, biochemistry, and therapeutic activity. Even so, we lack a comprehensive overview of major advances achieved by applying biotechnology to venom systems. This review therefore considers the methods, insights, and potential future developments of biotechnological applications in the field of venom research. We follow the levels of biological organization and structure, starting with the methods used to study the genomic blueprint and genetic machinery of venoms, followed gene products and their functional phenotypes. We argue that biotechnology can answer some of the most urgent questions in venom research, particularly when multiple approaches are combined together, and with other venomics technologies.

De Novo Transcriptome Analysis of the Venom of Latrodectus geometricus with the Discovery of an Insect-Selective Na Channel Modulator

The brown widow spider, Latrodectus geometricus, is a predator of a variety of agricultural insects and is also hazardous for humans. Its venom is a true pharmacopeia representing neurotoxic peptides targeting the ion channels and/or receptors of both vertebrates and invertebrates. The lack of transcriptomic information, however, limits our knowledge of the diversity of components present in its venom. The purpose of this study was two-fold: (1) carry out a transcriptomic analysis of the venom, and (2) investigate the bioactivity of the venom using an electrophysiological bioassay. From 32,505 assembled transcripts, 8 toxin families were classified, and the ankyrin repeats (ANK), agatoxin, centipede toxin, ctenitoxin, lycotoxin, scorpion toxin-like, and SCP families were reported in the L. geometricus venom gland. The diversity of L. geometricus venom was also uncovered by the transcriptomics approach with the presence of defensins, chitinases, translationally controlled tumor proteins (TCTPs), leucine-rich proteins, serine proteases, and other important venom components. The venom was also chromatographically purified, and the activity contained in the fractions was investigated using an electrophysiological bioassay with the use of a voltage clamp on ion channels in order to find if the neurotoxic effects of the spider venom could be linked to a particular molecular target. The findings show that U24-ctenitoxin-Pn1a involves the inhibition of the insect sodium (Na_v) channels, BgNa_v and DmNa_v. This study provides an overview of the molecular diversity of L. geometricus venom, which can be used as a reference for the venom of other spider species. The venom composition profile also increases our knowledge for the development of novel insecticides targeting voltage-gated sodium channels.

The biology and evolution of spider venoms

Spiders are diverse, predatory arthropods that have inhabited Earth for around 400 million years. They are well known for their complex venom systems that are used to overpower their prey. Spider venoms contain many proteins and peptides with highly specific and potent activities suitable for biomedical or agrochemical applications, but the key role of venoms as an evolutionary innovation is often overlooked, even though this has enabled spiders to emerge as one of the most successful animal lineages. In this review, we discuss these neglected biological aspects of spider venoms. We focus on the morphology of spider venom systems, their major components, biochemical and chemical plasticity, as well as ecological and evolutionary trends. We argue that the effectiveness of spider venoms is due to their unprecedented complexity, with diverse components working synergistically to increase the overall potency. The analysis of spider venoms is difficult to standardize because they are dynamic systems, fine-tuned and modified by factors such as sex, life-history stage and biological role. Finally, we summarize the mechanisms that drive spider venom evolution and highlight the need for genome-based studies to reconstruct the evolutionary history and physiological networks of spider venom compounds with more certainty.

Origin and Characterization of Extracellular Vesicles Present in the Spider Venom of Ornithoctonus hainana

Extracellular vesicles (EVs), including exosomes and microvesicles, are membranous vesicles released from nearly all cellular types. They contain various bioactive molecules, and their molecular composition varies depending on their cellular origin. As research into venomous animals has progressed, EVs have been discovered in the venom of snakes and parasitic wasps. Although vesicle secretion in spider venom glands has been observed, these secretory vesicles’ origin and biological properties are unknown. In this study, the origin of the EVs from Ornithoctonus hainana venom was observed using transmission electron microscopy (TEM). The Ornithoctonus hainana venom extracellular vesicles (HN-EVs) were isolated and purified by density gradient centrifugation. HN-EVs possess classic membranous vesicles with a size distribution ranging from 50 to 150 nm and express the arthropod EV marker Tsp29Fb. The LC-MS/MS analysis identified a total of 150 proteins, which were divided into three groups according to their potential function: conservative vesicle transport-related proteins, virulence-related proteins, and other proteins of unknown function. Functionally, HN-EVs have hyaluronidase activity and inhibit the proliferation of human umbilical vein endothelial cells (HUVECs) by affecting the cytoskeleton and cell cycle. Overall, this study investigates the biological characteristics of HN-EVs for the first time and sheds new light on the envenomation process of spider venom.

Animal Venoms and Their Components: Molecular Mechanisms of Action

Animal venoms comprise numerous toxin families, consisting mainly of peptides and proteins [...].

Complex precursor structures of cytolytic cupiennins identified in spider venom gland transcriptomes

Analysis of spider venom gland transcriptomes focuses on the identification of possible neurotoxins, proteins and enzymes. Here, the first comprehensive transcriptome analysis of cupiennins, small linear cationic peptides, also known as cytolytic or antimicrobial peptides, is reported from the venom gland transcriptome of Cupiennius salei by 454- and Illumina 3000 sequencing. Four transcript families with complex precursor structures are responsible for the expression of 179 linear peptides. Within the transcript families, after an anionic propeptide, cationic linear peptides are separated by anionic linkers, which are transcript family specific. The C-terminus of the transcript families is characterized by a linear peptide or truncated linkers with unknown function. A new identified posttranslational processing mechanism explains the presence of the two-chain CsTx-16 family in the venom. The high diversity of linear peptides in the venom of a spider and this unique synthesis process is at least genus specific as verified with Cupiennius getazi.

Caterpillar Venom: A Health Hazard of the 21st Century

Caterpillar envenomation is a global health threat in the 21st century. Every direct or indirect contact with the urticating hairs of a caterpillar results in clinical manifestations ranging from local dermatitis symptoms to potentially life-threatening systemic effects. This is mainly due to the action of bioactive components in the venom that interfere with targets in the human body. The problem is that doctors are limited to relieve symptoms, since an effective treatment is still lacking. Only for Lonomia species an effective antivenom does exist. The health and economical damage are an underestimated problem and will be even more of a concern in the future. For some caterpillar species, the venom composition has been the subject of investigation, while for many others it remains unknown. Moreover, the targets involved in the pathophysiology are poorly understood. This review aims to give an overview of the knowledge we have today on the venom composition of different caterpillar species along with their pharmacological targets. Epidemiology, mode of action, clinical time course and treatments are also addressed. Finally, we briefly discuss the future perspectives that may open the doors for future research in the world of caterpillar toxins to find an adequate treatment.