title: The roles of IP3 receptor in energy metabolic pathways and reactive oxygen species homeostasis revealed by metabolomic and biochemical studies.
abstract: Inositol 1,4,5-trisphosphate receptors (IP(3)Rs) are calcium channels modulating important calcium-mediated processes. Recent studies implicate IP(3)R in cell metabolism, but specific evidence is missing regarding IP(3)R's effects on actual metabolic pathways and key energy metabolites. Here, we applied metabolomics and molecular biology to compare DT40 cell lines devoid of IP(3)R (KO) and its wild-type (WT) counterpart. NMR and LC-MS metabolomic data showed that the KO cell line has a very different basic energy metabolism from the WT cell line, showing enhanced Warburg effect. In particular, the KO cells exhibited significant perturbation in energy charge, reduced glutathione and NADPH ratios with slower cellular growth rate. Subsequent flow cytometry results showed that the KO cell line has a higher level of general reactive oxygen species (ROS) but has a lower level of peroxynitrites. This ROS disturbance could be explained by observing lower expression of superoxide dismutase 2 (SOD2) and unchanged expression of catalase. The higher ROS seems to be involved in the slower growth rate of the KO cells, with an ROS scavenger increasing their growth rate. However, the KO and WT cell lines did not show any noticeable differences in AMPK and phosphorylated AMPK levels, suggesting possible saturation of AMPK-mediated metabolic regulatory circuit in both cells. Overall, our study reveals IP3R's roles in ROS homeostasis and metabolic pathways as well as the effects of its KO on cellular phenotypes.
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: He
authors.initials: H
authors.lastname: Wen
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Wen Jun
authors.initials: WJ
authors.lastname: Xu
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Xing
authors.initials: X
authors.lastname: Jin
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Sehyun
authors.initials: S
authors.lastname: Oh
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Chau Hong Duc
authors.initials: CH
authors.lastname: Phan
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Jayoung
authors.initials: J
authors.lastname: Song
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Sang Kook
authors.initials: SK
authors.lastname: Lee
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: psh@snu.ac.kr.
authors.forename: Sunghyouk
authors.initials: S
authors.lastname: Park
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004734:Energy Metabolism / Q000502:physiology*; D055785:Gene Knockdown Techniques; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000235:genetics / Q000378:metabolism*; D009249:NADP / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D000099156:Superoxide Dismutase 2
chemical_list: D055372:AMP-Activated Protein Kinases; D053496:Inositol 1,4,5-Trisphosphate Receptors; D009249:NADP; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D000099156:Superoxide Dismutase 2
keywords: DT40; Energy metabolism; IP(3)R; Metabolomics; ROS