title: Impact of dihydrolipoic acid on mouse embryonic stem cells and related regulatory mechanisms.
abstract: α-Lipoic acid (LA) is a thiol with antioxidant properties that protects against oxidative stress-induced apoptosis. LA is absorbed from the diet, taken up by cells and tissues, and subsequently reduced to dihydrolipoic acid (DHLA). Recently, DHLA has been used as the hydrophilic nanomaterial preparations, and therefore, determination of its bio-safety profile is essential. In this article, we show that DHLA (50-100 μM) induces apoptotic processes in mouse embryonic stem cells (ESC-B5), but exerts no injury effects at treatment dosages below 50 μM. Higher concentrations of DHLA (50-100 μM) directly increased the reactive oxygen species (ROS) content in ESC-B5 cells, along with a significant increase in cytoplasmic free calcium and nitric oxide (NO) levels, loss of mitochondrial membrane potential (MMP), activation of caspases-9 and -3, and cell death. Pretreatment with NO scavengers suppressed the apoptotic biochemical changes induced by 100 μM DHLA and promoted the gene expression levels of p53 and p21 involved in apoptotic signaling. Our results collectively indicate that DHLA at concentrations of 50-100 μM triggers apoptosis of ESC-B5 cells, which involves both ROS and NO. Importantly, at doses of less than 50 μM (0-25 μM), DHLA does not exert hazardous effects on ESC-B5 cell properties, including viability, development and differentiation. These results provide important information in terms of dosage safety and biocompatibility of DHLA to facilitate its further use as a precursor for biomaterial preparation.
authors.affiliation: Department of Bioscience Technology, Chung Yuan Christian University, Chung Li 32023, Taiwan.
authors.forename: Wen-Hsiung
authors.initials: WH
authors.lastname: Chan
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Houng
authors.forename: Cheng-An J
authors.initials: CA
authors.lastname: Lin
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Lee
authors.forename: Po-Wen
authors.initials: PW
authors.lastname: Li
authors.forename: Jyun-Tai
authors.initials: JT
authors.lastname: Hsieh
authors.forename: Ji-Lin
authors.initials: JL
authors.lastname: Shen
authors.forename: Hung-I
authors.initials: HI
authors.lastname: Yeh
authors.forename: Walter H
authors.initials: WH
authors.lastname: Chang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D008063:Thioctic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D008063:Thioctic Acid; C015144:dihydrolipoic acid; C505409:Casp3 protein, mouse; C506434:Casp9 protein, mouse; D053148:Caspase 3; D053453:Caspase 9; D002118:Calcium