Posters
Presentation Type
Poster
Discipline Track
Biomedical Science
Abstract Type
Research/Clinical
Abstract
Background: The World Health Organization (WHO) has recognized snakebite as a neglected tropical disease that affects nearly 2.7 million people per year and causes both long-term morbidity and substantial mortality. The multifunctionality of snake venom and the diversity of cellular responses to snake venom insult are well recognized. However, the neurotoxic effects of snake venom insult on the human nervous system are not yet fully understood. Therefore, a robust cell model that is easily reproducible and scalable to a larger sample size is required to aid the discovery of molecular mechanisms involved in the neurobiology of snake envenomation in humans. The Mojave rattlesnake (Crotalus scutulatus scutulatus) is a highly venomous pit viper commonly found in the arid regions of southeastern California, southern Nevada, southwestern Arizona, the southwestern corner of New Mexico, western Texas, and Mexico and is included in the “highest medically important” risk category in the United States and by the WHO. Initial proteomic analyses of the Mojave rattlesnake venom indicate that it is rich in snake venom phospholipases (svPLA2), snake venom metalloproteases (svMP), and snake venom serine proteases (svSP) of which svPLA2 constitutes ~20% of the venom.
Methods: To model the neurotoxic effect of Mojave rattlesnake envenomation, we performed an in-vitro snake venom challenge in human induced pluripotent stem cell (iPSC) derived neural stem cells (NSCs) of four participants of our Mexican American Family Study (MAFS). Well-characterized NSCs in in-vitro cultures were exposed to 10 μg/ml Mojave rattlesnake venom for 24 hours and then phenotyped for genome-wide differential gene expression by mRNA sequencing (mRNAseq).
Results: Transcriptomic analysis of the pre- (vehicle-treated) and post-venom challenged NSCs identified 373 genes that were significantly (moderated t statistics p-value ≤ 0.05 and Fold-Change-absolute ≥ 2.0) differentially expressed (DE). The 232 genes that were up-regulated post-venom challenge showed significant enrichment in dicarboxylic acid metabolism, cellular-modified amino acid, and nonribosomal peptide biosynthetic processes, serine and cysteine metabolism, folic acid metabolism, cell redox homeostasis, and glutathione biosynthetic processes, ER stress-associated pathways including apoptosis, tau-protein kinase activity, endothelial response to laminar fluid shear stress, response to arsenic-containing substances Gene Ontology (GO) terms. The 141 genes that were significantly down-regulated post-venom challenge suggest significant inhibition of synaptic transmission and signaling pathways, neurotransmitter uptake and transport, locomotory-, startle- and auditory stimulus responses, catecholamine metabolism, and axoneme and microtubule assembly.
The svPLA2, svMP, and svSP in the snake venom recruit prey analogs of similar activity including arachidonic acid, intracellular calcium, cytokines, and bioactive peptides to induce cytotoxic injury. Prey paralysis, though the precise mechanism is not fully understood, likely results from a self-amplifying cycle of endogenous PLA2 activation, arachidonic acid production, increases in intracellular Ca2+, deactivation of the nicotinic receptor, and synaptic suppression.
Conclusions: Our results show that the NSC response to Mojave rattlesnake venom recapitulates the neurocellular response to svPLA2, svMP, and svSP and iPSC-derived NSCs that are easily scalable to a larger sample size, is a relevant cell model to investigate the molecular mechanisms of snake venom neurotoxicity.
Academic/Professional Position
Staff
Mentor/PI Department
Office of Human Genetics
Recommended Citation
Aceves, Miriam; Granados, Jose C.; Leandro, Ana C.; Peralta, Juan M.; Williams-Blangero, Sarah; Galan, Jacob; Blangero, John; Curran, Joanne E.; and Kumar, Satish, "Human iPSC derived neural stem cells: An in-vitro model to investigate snake venom neurotoxicity" (2024). Research Symposium. 71.
https://scholarworks.utrgv.edu/somrs/2023/posters/71
Included in
Human iPSC derived neural stem cells: An in-vitro model to investigate snake venom neurotoxicity
Background: The World Health Organization (WHO) has recognized snakebite as a neglected tropical disease that affects nearly 2.7 million people per year and causes both long-term morbidity and substantial mortality. The multifunctionality of snake venom and the diversity of cellular responses to snake venom insult are well recognized. However, the neurotoxic effects of snake venom insult on the human nervous system are not yet fully understood. Therefore, a robust cell model that is easily reproducible and scalable to a larger sample size is required to aid the discovery of molecular mechanisms involved in the neurobiology of snake envenomation in humans. The Mojave rattlesnake (Crotalus scutulatus scutulatus) is a highly venomous pit viper commonly found in the arid regions of southeastern California, southern Nevada, southwestern Arizona, the southwestern corner of New Mexico, western Texas, and Mexico and is included in the “highest medically important” risk category in the United States and by the WHO. Initial proteomic analyses of the Mojave rattlesnake venom indicate that it is rich in snake venom phospholipases (svPLA2), snake venom metalloproteases (svMP), and snake venom serine proteases (svSP) of which svPLA2 constitutes ~20% of the venom.
Methods: To model the neurotoxic effect of Mojave rattlesnake envenomation, we performed an in-vitro snake venom challenge in human induced pluripotent stem cell (iPSC) derived neural stem cells (NSCs) of four participants of our Mexican American Family Study (MAFS). Well-characterized NSCs in in-vitro cultures were exposed to 10 μg/ml Mojave rattlesnake venom for 24 hours and then phenotyped for genome-wide differential gene expression by mRNA sequencing (mRNAseq).
Results: Transcriptomic analysis of the pre- (vehicle-treated) and post-venom challenged NSCs identified 373 genes that were significantly (moderated t statistics p-value ≤ 0.05 and Fold-Change-absolute ≥ 2.0) differentially expressed (DE). The 232 genes that were up-regulated post-venom challenge showed significant enrichment in dicarboxylic acid metabolism, cellular-modified amino acid, and nonribosomal peptide biosynthetic processes, serine and cysteine metabolism, folic acid metabolism, cell redox homeostasis, and glutathione biosynthetic processes, ER stress-associated pathways including apoptosis, tau-protein kinase activity, endothelial response to laminar fluid shear stress, response to arsenic-containing substances Gene Ontology (GO) terms. The 141 genes that were significantly down-regulated post-venom challenge suggest significant inhibition of synaptic transmission and signaling pathways, neurotransmitter uptake and transport, locomotory-, startle- and auditory stimulus responses, catecholamine metabolism, and axoneme and microtubule assembly.
The svPLA2, svMP, and svSP in the snake venom recruit prey analogs of similar activity including arachidonic acid, intracellular calcium, cytokines, and bioactive peptides to induce cytotoxic injury. Prey paralysis, though the precise mechanism is not fully understood, likely results from a self-amplifying cycle of endogenous PLA2 activation, arachidonic acid production, increases in intracellular Ca2+, deactivation of the nicotinic receptor, and synaptic suppression.
Conclusions: Our results show that the NSC response to Mojave rattlesnake venom recapitulates the neurocellular response to svPLA2, svMP, and svSP and iPSC-derived NSCs that are easily scalable to a larger sample size, is a relevant cell model to investigate the molecular mechanisms of snake venom neurotoxicity.