Effects of Lonomia obliqua caterpillar venom upon the proliferation and viability of cell lines

Mechanisms involved in the cytoprotective effects of Lonomia obliqua venom on human endometrial stromal cells

The pathophysiology of recurrent pregnancy loss (RPL) involves deficiencies in the proliferation and migration capacities of endometrial stromal cells (hESCs), which impair embryo implantation and development. Since animal venoms are rich source of bioactive molecules, we aimed to characterize the cytoprotective effects of Lonomia obliqua venom on hESCs. hESCs were isolated from endometrial biopsies and the mechanisms of L. obliqua venomous secretions on cell viability, proliferation and migration were characterized. Venom components were identified by chromatography and proteomic analyses. L. obliqua venom induced hESC proliferation, viability and migration in a dose-dependent manner, both in the presence and absence of serum. By ion-exchange chromatography, one fraction enriched in cytoprotective components and devoid of hemotoxins was obtained. Venom proteome identified at least six protein classes with potential cytoprotective properties (hemolins, lipocalins, hemocyannins, antiviral proteins, antimicrobial peptides, and protease inhibitors). L. obliqua venom protected hESCs from oxidative insult. Cytoprotection was also related to nitric oxide and PKC-ERK-activation and down-regulation of cAMP-PKA-dependent pathways that control cell proliferation. L. obliqua venom-induced hESC viability, proliferation and migration occurs mainly by protecting against oxidative damage and activating ERK. Thus, L. obliqua venom components are promising pharmacological tools to understand the underlying mechanisms of hESC deficiency in RPL.

Losac and Lopap Recombinant Proteins from Lonomia obliqua Bristles Positively Modulate the Myoblast Proliferation Process

The pursuit of better therapies for disorders creating deficiencies in skeletal muscle regeneration is in progress, and several biotoxins are used in skeletal muscle research. Since recombinant proteins derived from Lonomia obliqua bristles, recombinant Lonomia obliqua Stuart-factor activator (rLosac) and recombinant Lonomia obliqua prothrombin activator protease (rLopap) act as cytoprotective agents and promote cell survival, we hypothesize that both rLosac and rLopap favour the skeletal muscle regeneration process. In the present work, we investigate the ability of these recombinant proteins rLosac and rLopap to modulate the production of key mediators of the myogenic process. The expression of myogenic regulatory factors (MRFs), cell proliferation, the production of prostaglandin E2 (PGE₂) and the protein expression of cyclooxygenases COX-1 and COX-2 were evaluated in C2C12 mouse myoblasts pre-treated with rLosac and rLopap. We found an increased proliferation of myoblasts, stimulated by both recombinant proteins. Moreover, these proteins modulated PGE₂ release and MRFs activities. We also found an increased expression of the EP4 receptor in the proliferative phase of C2C12 cells, suggesting the involvement of this receptor in the effects of PGE₂ in these cells. Moreover, the recombinant proteins inhibited the release of IL-6 and PGE₂, which is induced by an inflammatory stimulus by IL-1β. This work reveals rLopap and rLosac as promising proteins to modulate processes involving tissue regeneration as occurs during skeletal muscle injury.

Lonomia obliqua Envenoming and Innovative Research

As a tribute to Butantan Institute in its 120th anniversary, this review describes some of the scientific research efforts carried out in the study of Lonomia envenoming in Brazil, a country where accidents with caterpillars reach over 42,000 individuals per year (especially in South and Southeast Brazil). Thus, the promising data regarding the studies with Lonomia’s toxins contributed to the creation of new research centers specialized in toxinology based at Butantan Institute, as well as to the production of the antilonomic serum (ALS), actions which are in line with the Butantan Institute mission “to research, develop, manufacture, and provide products and services for the health of the population”. In addition, the study of the components of the Lonomia obliqua bristle extract led to the discovery of new molecules with peculiar properties, opening a field of knowledge that could lead to the development and innovation of new drugs aimed at cell regeneration and inflammatory diseases.

Lonomia obliqua Venom Induces NF-κB Activation and a Pro-Inflammatory Profile in THP-1-Derived Macrophage

Envenomation caused by contact with Lonomia obliqua bristles is characterized by pain, an intense systemic proinflammatory reaction and disturbances in the coagulation cascade that can cause severe clinical manifestations and death. However, the role of immune system components in these effects is still poorly understood. In this study, we evaluated the cytotoxic effect of L. obliqua venom on THP-1-derived macrophages and its ability to modulate inflammatory markers, as well as the cytokine and chemokine release profile. Our results show that L. obliqua venom is able to directly exert a potent pro-inflammatory reaction in macrophages, characterized by the activation of the NF-κB transcription factor pathway, the expression of CD80 and CD83, and the release of pro-inflammatory mediators such as TNF-α, IL-1β, IL-6, IL-8 and CXCL10. These results suggest that macrophages can play an important role during the orchestration of the inflammatory response present in envenomation caused by Lonomia obliqua caterpillars.

In vitro antitumor, pro-inflammatory, and pro-coagulant activities of Megalopyge opercularis J.E. Smith hemolymph and spine venom

Contact with stinging spines venom from several Lepidoptera larvae may result in skin lesions. In Mexico, envenomation outbreaks caused by Megalopyge opercularis were reported between 2015 and 2016. The aim of this study was to identify the venomous caterpillars in Nuevo Leon, Mexico and evaluate several biological activities of their hemolymph (HEV) and spine setae (SSV) venoms. M. opercularis was identified by cytochrome oxidase subunit (COI) designed primers. HEV and SSV extracts cytotoxic activity was assessed on the L5178Y-R lymphoma cell line. For apoptotic cells number and apoptosis, cells were stained with acridine orange/ethidium bromide and validated by DNA fragmentation. Human peripheral blood mononuclear cells (hPBMC) cytokine response to the extracts was measured by the cytometric bead array assay. Extracts effect on pro-coagulation activity on human plasma was also evaluated. HEV and SSV extracts significantly inhibited (p < 0.01) up to 63% L5178Y-R tumor cell growth at 125–500 µg/mL, as compared with 43% of Vincristine. About 79% extracts-treated tumor cells death was caused by apoptosis. Extracts stimulated (p < 0.01) up to 60% proliferation of resident murine lymphocytes, upregulated IL-1β, IL-6, IL-8, and TNF-α production by hPBMC, and showed potent pro-coagulant effects. The pharmacological relevance of these venoms is discussed.

In-depth transcriptome reveals the potential biotechnological application of Bothrops jararaca venom gland

Background:

Lack of complete genomic data of Bothrops jararaca impedes molecular biology research focusing on biotechnological applications of venom gland components. Identification of full-length coding regions of genes is crucial for the correct molecular cloning design.

Methods:

RNA was extracted from the venom gland of one adult female specimen of Bothrops jararaca. Deep sequencing of the mRNA library was performed using Illumina NextSeq 500 platform. De novo assembly of B. jararaca transcriptome was done using Trinity. Annotation was performed using Blast2GO. All predicted proteins after clustering step were blasted against non-redundant protein database of NCBI using BLASTP. Metabolic pathways present in the transcriptome were annotated using the KAAS-KEGG Automatic Annotation Server. Toxins were identified in the B. jararaca predicted proteome using BLASTP against all protein sequences obtained from Animal Toxin Annotation Project from Uniprot KB/Swiss-Pro database. Figures and data visualization were performed using ggplot2 package in R language environment.

Results:

We described the in-depth transcriptome analysis of B. jararaca venom gland, in which 76,765 de novo assembled isoforms, 96,044 transcribed genes and 41,196 unique proteins were identified. The most abundant transcript was the zinc metalloproteinase-disintegrin-like jararhagin. Moreover, we identified 78 distinct functional classes of proteins, including toxins, inhibitors and tumor suppressors. Other venom proteins identified were the hemolytic lethal factors stonustoxin and verrucotoxin.

Conclusion:

It is believed that the application of deep sequencing to the analysis of snake venom transcriptomes may represent invaluable insight on their biotechnological potential focusing on candidate molecules.

Lonomia obliqua bristle extract modulates Rac1 activation, membrane dynamics and cell adhesion properties

Lonomia obliqua is a caterpillar of potential therapeutic interest whose venom is able to induce severe blood leakage and modulate leukocyte migration. Since both phenotypes are associated with changes in cytoskeleton dynamics and cell adhesion properties, the aim of this study was to analyze the effects of Lonomia obliqua bristle extract (LOBE) in cell adhesion and migration signaling. Proteomic analysis revealed that epithelial cells (CHO-K1) exposed to LOBE (30 μg/mL, 30 min) exhibited changes in levels of actin regulatory proteins, including RhoGTPases. These changes correlated with an increase in the activity of the RhoGTPase family member Rac as measured by Förster resonance energy transfer (FRET). When plated in migration promoting conditions, CHO-K1 cells exposed to LOBE (10 μg/mL) showed an increase in membrane ruffling after short (30 min) period of incubation that was accompanied by changes in the distribution of the adhesion markers paxillin, vinculin and an increase of focal adhesion kinase autophosphorylation levels (Y397), suggesting changes in cell-extracellular matrix (ECM) adhesion properties and signaling. These data suggest that LOBE possesses bioactive molecules that are capable to modulated cell migration signaling, cytoskeletal dynamics and cell-ECM properties of several cell types.

Characterization of Leiurus abdullahbayrami (Scorpiones: Buthidae) venom: peptide profile, cytotoxicity and antimicrobial activity

BACKGROUND

Scorpion venoms are rich bioactive peptide libraries that offer promising molecules that may lead to the discovery and development of new drugs. Leiurus abdullahbayrami produces one of the most potent venoms among Turkish scorpions that provokes severe symptoms in envenomated victims.

METHODS

In the present study, the peptide profile of the venom was investigated by electrophoretic methods, size-exclusion and reversed-phase chromatography and mass spectroscopy. Cytotoxic and antimicrobial effects were evaluated on a breast cancer cell line (MCF-7) and various bacterial and fungal species.

RESULTS

Proteins make up approximately half of the dry weight of L. abdullahbayrami crude venom. Microfluidic capillary electrophoresis indicated the presence of 6 to 7 kDa peptides and proved to be a highly practical peptidomics tool with better resolution when compared to conventional polyacrylamide gel electrophoresis. Mass spectroscopy analysis helped us to identify 45 unique peptide masses between 1 to 7 kDa with a bimodal mass distribution peaking between molecular weights of 1 to 2 kDa (29%) and 3 to 4 kDa (31%). L. abdullahbayrami crude venom had a proliferative effect on MCF-7 cells, which may be explained by the high concentration of polyamines as well as potassium and calcium ions in the arachnid venoms. Antimicrobial effect was stronger on gram-negative bacteria.

CONCLUSIONS

This work represents the first peptidomic characterization of L. abdullahbayrami venom. Considering the molecular weight-function relationship of previously identified venom peptides, future bioactivity studies may lead to the discovery of novel potassium and chloride ion channel inhibitors as well as new antimicrobial peptides from L. abdullahbayrami venom.