title: Inhibition of autophagy contributes to the toxicity of cadmium telluride quantum dots in Saccharomyces cerevisiae.
abstract: Cadmium telluride quantum dots (CdTe QDs) are used as near-infrared probes in biologic and medical applications, but their cytological effects and mechanism of potential toxicity are still unclear. In this study, we evaluated the toxicity of CdTe QDs of different sizes and investigated their mechanism of toxicity in the yeast Saccharomyces cerevisiae. A growth inhibition assay revealed that orange-emitting CdTe (O-CdTe) QDs (half inhibitory concentration [IC50] =59.44±12.02 nmol/L) were more toxic than green-emitting CdTe QDs (IC50 =186.61±19.74 nmol/L) to S. cerevisiae. Further studies on toxicity mechanisms using a transmission electron microscope and green fluorescent protein tagged Atg8 processing assay revealed that O-CdTe QDs could partially inhibit autophagy at a late stage, which differs from the results reported in mammalian cells. Moreover, autophagy inhibited at a late stage by O-CdTe QDs could be partially recovered by enhancing autophagy with rapamycin (an autophagy activator), combined with an increased number of living cells. These results indicate that inhibition of autophagy acts as a toxicity mechanism of CdTe QDs in S. cerevisiae. This work reports a novel toxicity mechanism of CdTe QDs in yeast and provides valuable information on the effect of CdTe QDs on the processes of living cells.
authors.affiliation: College of Life Sciences, Wuhan University; Hubei Provincial Cooperative Innovation Center of Industrial Fermentation; State Key Laboratory of Virology; Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE).
authors.forename: Junpeng
authors.initials: J
authors.lastname: Fan
authors.affiliation: College of Life Sciences, Wuhan University; Hubei Provincial Cooperative Innovation Center of Industrial Fermentation; State Key Laboratory of Virology; Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE).
authors.forename: Ming
authors.initials: M
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Virology; Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE); College of Chemistry and Molecular Sciences, Wuhan University, Wuhan.
authors.forename: Lu
authors.initials: L
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Virology; Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE); College of Chemistry and Molecular Sciences, Wuhan University, Wuhan.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Life Sciences, Wuhan University; Hubei Provincial Cooperative Innovation Center of Industrial Fermentation; State Key Laboratory of Virology; Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE); School of Life Science and Technology, Hubei Engineering University, Xiaogan, People's Republic of China.
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: Xie
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D019187:Cadmium Compounds / Q000633:toxicity*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D045663:Quantum Dots / Q000633:toxicity*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000648:ultrastructure; D020123:Sirolimus / Q000494:pharmacology; D013691:Tellurium / Q000633:toxicity*; D014617:Vacuoles / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D019187:Cadmium Compounds; D049452:Green Fluorescent Proteins; D013691:Tellurium; C028337:cadmium telluride; D020123:Sirolimus
keywords: CdTe quantum dots; Saccharomyces cerevisiae; autophagy; toxicity