Scolopendin 2 leads to cellular stress response in Candida albicans

Abstract

Centipedes, a kind of arthropod, have been reported to produce antimicrobial peptides as part of an innate immune response. Scolopendin 2 (AGLQFPVGRIGRLLRK) is a novel antimicrobial peptide derived from the body of the centipede Scolopendra subspinipes mutilans by using RNA sequencing. To investigate the intracellular responses induced by scolopendin 2, reactive oxygen species (ROS) and glutathione accumulation and lipid peroxidation were monitored over sublethal and lethal doses. Intracellular ROS and antioxidant molecule levels were elevated and lipids were peroxidized at sublethal concentrations. Moreover, the Ca(2+) released from the endoplasmic reticulum accumulated in the cytosol and mitochondria. These stress responses were considered to be associated with yeast apoptosis. Candida albicans cells exposed to scolopendin 2 were identified using diagnostic markers of apoptotic response. Various responses such as phosphatidylserine externalization, chromatin condensation, and nuclear fragmentation were exhibited. Scolopendin 2 disrupted the mitochondrial membrane potential and activated metacaspase, which was mediated by cytochrome c release. In conclusion, treatment of C. albicans with scolopendin 2 induced the apoptotic response at sublethal doses, which in turn led to mitochondrial dysfunction, metacaspase activation, and cell death. The cationic antimicrobial peptide scolopendin 2 from the centipede is a potential antifungal peptide, triggering the apoptotic response.