title: Reduced scytonemin isolated from Nostoc commune induces autophagic cell death in human T-lymphoid cell line Jurkat cells.
abstract: Nostoc commune is a terrestrial benthic blue-green alga that often forms an extended mucilaginous layer on the soil, accumulates on stones and mud in aquatic environments. Reduced-scytonemin (R-scy), isolated from N. commune Vaucher, has been shown to suppress the human T-lymphoid Jurkat cell growth. To reveal the mechanisms underlying the R-scy-mediated inhibition of Jurkat cell growth, we examined cell morphology, DNA fragmentation, and microtubule-associated protein light chain 3 (LC3) modification in these cells. We observed multiple vacuoles as well as the conversion of LC3-I to LC3-II in R-scy-treated cells. These results suggest that the R-scy induced Jurkat cell growth inhibition is attributable to the induction of type II programmed cell death (PCD II; autophagic cell death or autophagy). We further examined the mechanisms underlying R-scy-induced PCDII. The cells treated with R-scy produced large amounts of reactive oxygen species (ROS), leading to the induction of mitochondrial dysfunction. However, the elimination of R-scy-induced ROS by treatment with N-acetyl-L-cysteine (NAC) markedly opposed R-scy-induced PCDII. Based on these results, we conclude that ROS formation plays a critical role in R-scy-induced PCDII.
authors.affiliation: Laboratory of Aquatic Food Science, Department of Fisheries, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan. Electronic address: titoh@nara.kindai.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Itoh
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tsuzuki
authors.forename: Toshiomi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ninomiya
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takenaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Ando
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Tsukamasa
authors.forename: Mamoru
authors.initials: M
authors.lastname: Koketsu
mesh_terms: D001343:Autophagy / Q000187:drug effects*; D002460:Cell Line; D006801:Humans; D007211:Indoles / Q000737:chemistry* / Q000302:isolation & purification*; D019169:Jurkat Cells; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D050501:Nostoc commune / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism
chemical_list: D007211:Indoles; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D010636:Phenols; D017382:Reactive Oxygen Species; C083368:scytonemin
keywords: Autophagy; Intracellular ROS; Nostoc commune Vauch; Reduced scytonemin; Type II programmed cell death