文献类型： 外文期刊

作者： Prause, Helene-Christine ¹ ; Hochmayr, Nadine ¹ ; Yu, Yanan ³ ; Larsen, Thomas Ostenfeld ³ ; Hansen, Per Juel ⁵ ; Del Favero, Giorgia ¹ ; Marko, Doris ¹ ; Place, Allen ⁷ ; Varga, Elisabeth ¹ ;

作者机构： 1.Univ Vienna, Fac Chem, Dept Food Chem & Toxicol, Wahringer Str 38-40, A-1090 Vienna, Austria

2.Univ Vienna, Fac Chem, Vienna Doctoral Sch Chem, Wahringer Str 42, A-1090 Vienna, Austria

3.Tech Univ Denmark, Dept Biotechnol & Biomed, Soltofts Plads 221, DK-2800 Lyngby, Denmark

4.Chinese Acad Fishery Sci, East China Sea Fisheries Res Inst, Key Lab Ocean & Polar Fisheries, Minist Agr & Rural Affairs, Jungong Rd 300, Shanghai 200090, Peoples R China

5.Univ Copenhagen, Dept Biol, Marine Biol Sect, Strandpromenaden 5, DK-3000 Elsinore, Denmark

6.Univ Vienna, Fac Chem, Core Facil Multimodal Imaging, Wahringer Str 38-42, A-1090 Vienna, Austria

7.Univ Maryland, Inst Marine & Environm Technol, Ctr Environm Sci, 701 E Pratt St, Baltimore, MD 21202 USA

8.Univ Vet Med, Ctr Food Sci & Vet Publ Hlth, Clin Dept Farm Anim & Food Syst Sci, Unit Food Hyg & Technol, Veterinarpl 1, A-1210 Vienna, Austria

关键词： Ichthyotoxin; Mode of action; Lysis; Cholesterol; RTgill-W1; HCEC-1CT

期刊名称：HARMFUL ALGAE （ 影响因子：4.5； 五年影响因子：5.9 ）

ISSN： 1568-9883

年卷期： 2025 年 143 卷

页码：

收录情况： SCI

摘要： Karmitoxin, produced by Karlodinium armiger, is structurally related to karlotoxin and amphidinols, two potent ichthyotoxic hemolysins with high affinity for sterols. Given these structural similarities, karmitoxin is believed to exhibit comparable toxic effects. Cytotoxicity was assessed in the fish gill cell line RTgill-W1 and the human epithelial colon cell line HCEC-1CT. The hemolytic potential with and without added sterols was tested on fish erythrocytes to investigate possible impacts of toxin-sterol interactions. Sterol interactions were further evaluated using surface plasmon resonance. A 3-h incubation returned an EC50 of 111 and 175 nM in RTgill-W1 and in HCEC-1CT cells, respectively. Lactate dehydrogenase (LDH) release increased with toxin concentration, reaching 11 % in the fish and 40 % in the human cell line. Extended exposure (24 h) increased the toxicity in RTgill-W1 cells (EC50 74 nM, 40 % LDH release). In parallel, hemolytic potential of karmitoxin was confirmed, as well as its interaction with free sterols. Interaction kinetics revealed complex stabilities with kd(s_ 1) constants of 1.13 x 10_2 (cholesterol), 5.48 x 10_ 3 (epicholesterol), and 4.72 x 10_ 3 (ergosterol). Interaction with cholesterol followed the single-exponential model well, while data indicated more complex binding with epicholesterol and ergosterol. Altering the RTgill-W1 cholesterol content did not impact cytotoxicity at the tested concentration. Overall, karmitoxin showed potent cytotoxic and hemolytic properties in human and fish models. Complex formation with sterols may play a role in membrane targeting, yet cellular cholesterol quantity might not affect cytotoxicity.