Scientific reports
-
Cone snails are a diverse group of predatory marine invertebrates that deploy remarkably complex venoms to rapidly paralyse worm, mollusc or fish prey. ω-Conotoxins are neurotoxic peptides from cone snail venoms that inhibit Cav2.2 voltage-gated calcium channel, demonstrating potential for pain management via intrathecal (IT) administration. Here, we isolated and characterized two novel ω-conotoxins, MoVIA and MoVIB from Conus moncuri, the first to be identified in vermivorous (worm-hunting) cone snails. MoVIA and MoVIB potently inhibited human Cav2.2 in fluorimetric assays and rat Cav2.2 in patch clamp studies, and both potently displaced radiolabeled ω-conotoxin GVIA (125I-GVIA) from human SH-SY5Y cells and fish brain membranes (IC50 2-9 pM). ⋯ Interestingly, MVIIA-[Y13R] completely lost Cav2.2 activity and MoVIB-[R13Y] had reduced activity, indicating that Arg at position 13 was preferred in these vermivorous ω-conotoxins whereas tyrosine 13 is preferred in piscivorous ω-conotoxins. MoVIB reversed pain behavior in a rat neuropathic pain model, confirming that vermivorous cone snails are a new source of analgesic ω-conotoxins. Given vermivorous cone snails are ancestral to piscivorous species, our findings support the repurposing of defensive venom peptides in the evolution of piscivorous Conidae.
-
Whether blood transfusion exacerbates cancer outcomes after surgery in humans remains inconclusive. We utilized a large cohort to investigate the effect of perioperative blood transfusion on cancer prognosis following colorectal cancer (CRC) resection. Patients with stage I through III CRC undergoing tumour resection at a tertiary medical center between 2005 and 2014 were identified and evaluated through August 2016. ⋯ Preoperative anemia was not associated with decreased survival after adjusting covariates. Perioperative blood transfusion was associated with worse cancer prognosis after curative colorectal resection, independently of anemia status. Strategies aimed at minimizing transfusion requirements should be further developed.