Purificación parcial de péptidos y actividad citotóxica del veneno T. macrochirus

Antimicrobial Activity Developed by Scorpion Venoms and Its Peptide Component

Microbial infections represent a problem of great importance at the public health level, with a high rate of morbidity-mortality worldwide. However, treating the different diseases generated by microorganisms requires a gradual increase in acquired resistance when applying or using them against various antibiotic therapies. Resistance is caused by various molecular mechanisms of microorganisms, thus reducing their effectiveness. Consequently, there is a need to search for new opportunities through natural sources with antimicrobial activity. One alternative is using peptides present in different scorpion venoms, specifically from the Buthidae family. Different peptides with biological activity in microorganisms have been characterized as preventing their growth or inhibiting their replication. Therefore, they represent an alternative to be used in the design and development of new-generation antimicrobial drugs in different types of microorganisms, such as bacteria, fungi, viruses, and parasites. Essential aspects for its disclosure, as shown in this review, are the studies carried out on different types of peptides in scorpion venoms with activity against pathogenic microorganisms, highlighting their high therapeutic potential.

Scorpion Venom Polypeptide Inhibits Pulmonary Epithelial-Mesenchymal Transition in Systemic Sclerosis-Interstitial Lung Disease Model Mice by Intervening TGF-β1/Smad Signaling Pathway

Objective

Interstitial lung disease (ILD) is an important complication of systemic sclerosis (SSc). The aim of this study was to investigate the effect and possible mechanism of polypeptide extract of scorpion venom (PESV) on SSc-ILD.

Methods

C57/BL6 mice were injected with bleomycin to establish a SSc-ILD model. Different concentrations of PESV solution were administered to SSc-ILD mice, and dexamethasone was used as a positive control. H&E staining and Masson staining were used to observe the pathological changes. The TGF-β1 expression level was detected by immunohistochemistry. The expression of epithelial-mesenchymal transition (EMT)-related proteins was detected by Western blot, and the expression of TGF-β1/Smad pathway-related proteins was also detected. The content of inflammatory cytokines in serum and BALF was determined by ELISA.

Results

Pathological analysis showed that PESV could alleviate SSc-ILD-induced pulmonary inflammation and fibrosis. Compared with the model group, the content of inflammatory cytokines IL-6 and TNF-α significantly decreased after PESV treatment. PESV could increase the expression of epithelial marker (E-cadherin) and reduce the expression of interstitial markers (collagen I, vimentin, N-cadherin, and a-SMA). In addition, PESV could reduce the expression level of TGF-β1/Smad pathway-related protein.

Conclusion

PESV can attenuate SSc-ILD by regulating EMT, and the effect was linked to the TGF-β1/Smad signaling pathway, which indicated that PESV may serve as a candidate drug for SSc-ILD.

Structural and functional characterization of toxic peptides purified from the venom of the Colombian scorpion Tityus macrochirus

The soluble venom of the scorpion Tityus macrochirus was separated by chromatographic procedures and three homogeneous peptides were obtained and their primary structures were determined. They were called: Tma1-Tma3, from the abbreviated name of the scorpion. Tma1 is a peptide containing 65 amino acids with four disulfide linkages and a molecular weight of 7386.2 Da. It is a mammalian toxin, shown to affect human sodium-channels sub-types hNav1.6 and hNav1.4. Tma2 and Tma3 are peptides containing 69 amino acids linked by four disulfide bonds, molecular weights 7819.7 and 7830.0 Da, respectively. They do not affect human sodium-channels but are lethal to insects (crickets). A phylogenic analysis of the three peptides and those of other toxic peptides isolated from the genus Tityus and Centruroides were grouped together and analyzed, permitting to obtain a topology with two main clades, one includes most sodium-channel anti-insect scorpion toxins and others includes mostly sodium-channel scorpion toxins anti-mammalian. Tma1 segregates among a group of well-studied β-class toxins of other Tityus species such as T. discrepans, T. obscurus and T. pachyurus. Tma2 and Tma3 are associated with anti-insect toxins, particularly with one of T. obscurus. This phylogenetic analysis confirms and enforces our experimental results obtained with these three new sodium-channel scorpion toxins.