Scorpion venom heat-resistant synthetic peptide protects dopamine neurons against 6-hydroxydopamine neurotoxicity in C. elegans.

Parkinson's disease (PD) is a common neurodegenerative disease. The main pathological feature is the degeneration and loss of dopaminergic neurons in the substantia nigra, which leads to the significant decrease of dopamine content in the striatum. Our recent studies have shown that scorpion venom heat-resistant synthetic peptide (SVHRSP) have protective effects on neuroinflammation. In this study, using C. elegans induced by 6-hydroxydopamine (6-OHDA) as neurodegenerative model, we investigated the effect of SVHRSP on dopaminergic neurons neurotoxicity. Our results implied that SVHRSP treatment could improve the motor capacity in 6-OHDA-induced C. elegans and improve dopaminergic neuron mediated food sensitivity behavior. After SVHRSP treatment, dopaminergic neuron degeneration induced by 6-OHDA was significantly prevented along with a decreased α-synuclein aggregation and restored lipid deposition in C. elegans induced by 6-OHDA. We also observed the reduced levels of reactive oxygen species (ROS) after SVHRSP treatment in model-building C. elegans. In addition, the genes related to apoptosis, oxidative stress, like ctl-1, egl-1and cat-2 in C. elegans induced by 6-OHDA upregulated after treatment with SVHRSP. In conclusion, SVHRSP may impose anti-PD effect through its neuroprotective action on dopaminergic neurons. This study elucidates the effect and related mechanism of SVHRSP on PD and provides evidences for the therapeutic treatment of PD.

Scorpion Venom Heat-Resistant Synthesized Peptide Increases Stress Resistance and Extends the Lifespan of Caenorhabditis elegans via the Insulin/IGF-1-Like Signal Pathway.

Improving healthy life expectancy by targeting aging-related pathological changes has been the spotlight of geroscience. Scorpions have been used in traditional medicine in Asia and Africa for a long time. We have isolated heat-resistant peptides from scorpion venom of Buthusmartensii Karsch (SVHRP) and found that SVHRP can attenuate microglia activation and protect Caenorhabditis elegans (C. elegans) against ß-amyloid toxicity. Based on the amino acid sequence of these peptides, scorpion venom heat-resistant synthesized peptide (SVHRSP) was prepared using polypeptide synthesis technology. In the present study, we used C. elegans as a model organism to assess the longevity-related effects and underlying molecular mechanisms of SVHRSP in vivo. The results showed that SVHRSP could prolong the lifespan of worms and significantly improve the age-related physiological functions of worms. SVHRSP increases the survival rate of larvae under oxidative and heat stress and decreases the level of reactive oxygen species and fat accumulation in vivo. Using gene-specific mutation of C. elegans, we found that SVHRSP-mediated prolongation of life depends on Daf-2, Daf-16, Skn-1, and Hsf-1 genes. These results indicate that the antiaging mechanism of SVHRSP in nematodes might be mediated by the insulin/insulin-like growth factor-1 signaling pathway. Meanwhile, SVHRSP could also up-regulate the expression of stress-inducing genes Hsp-16.2, Sod-3, Gei-7, and Ctl-1 associated with aging. In general, our study may have important implications for SVHRSP to promote healthy aging and provide strategies for research and development of drugs to treat age-related diseases.