Effects of Scorpion venom peptide B5 on hematopoietic recovery in irradiated mice and the primary mechanisms

Abstract

Scorpion venom peptide B5 (SVP-B5) stimulates recovery of hematopoiesis after exposure to radiation. However, its radioprotective effects and mechanisms are still unclear. The aim of this study was to investigate the effects of SVP-B5 on hematopoietic recovery in mice after total body irradiation (TBI) at a dose of 7.5Gy and 6Gy and to explore the possible primary mechanisms. SVP-B5 at a dose of 2.63 μg/kg significantly reduced the mortality rate of mice after TBI (p < 0.05). It showed markedly protective effects against radiation injury. SVP-B5 also significantly increased the number of bone marrow nucleated cells (BMNCs) and increased the colony forming unit (CFU) number in irradiated mice, accelerated the post-irradiation recovery of peripheral blood leukocytes and platelets in mice. SVP-B5 treatment markedly reduced the Reactive Oxygen Species (ROS) levels in BMNCs after TBI, reduced γH2AX levels, and decreased the relative expression levels of p16 and p21 mRNA at day14 (d14) after irradiation. Our study indicated that SVP-B5 could partially mitigate radiation-induced DNA damage, enhance the post-radiation hematopoietic recovery, and improve the survival rate probably through the ROS-p16/p21 pathway.

SVP‑B5 peptide from Buthus?martensii Karsch scorpion venom exerts hyperproliferative effects on irradiated hematopoietic cells

“…The sequence of the SVP-B5 peptide has been previously discussed (10). Using the Basic Local Alignment Search Tool protein database (https://blast.ncbi.nlm.nih.gov/Blast.cgi), it was found that SVP-B5 shares >80% homology with the sequence of the α-toxins family (data not shown).…”

“…Our laboratory is continuously working on characterizing components from SVP and defining their effects on the post-radiation recovery of hematopoietic cells. The novel principal component SVP-B5 was isolated from the previously defined SVPII fraction (10). It was demonstrated that SVP-5B has hyperproliferative effects on irradiated hematopoietic cells.…”

“…Our group has focused on the SVP and SVPII from the Buthus martensii scorpion venom (10)(11)(12). A recent study by our group identified SVP-B5, a novel peptide from the SVPII, which mitigates radiation-induced DNA damage and improves the survival rate through the reactive oxygen species-p16/p21 pathway (10). In another study by our group, hematopoietic growth factor-like effects of SVPII were reported (12).…”

“…These scorpion venom polypeptides (SVPs) have been demonstrated to have a diverse array of biological activities with high specificities to their targeted sites, including anti-tumor, anti-epileptic, analgesic and ion channel blocking properties (5)(6)(7)(8)(9). Our group has focused on the SVP and SVPII from the Buthus martensii scorpion venom (10)(11)(12). A recent study by our group identified SVP-B5, a novel peptide from the SVPII, which mitigates radiation-induced DNA damage and improves the survival rate through the reactive oxygen species-p16/p21 pathway (10).…”