title: From the Cover: Thirdhand Cigarette Smoke Causes Stress-Induced Mitochondrial Hyperfusion and Alters the Transcriptional Profile of Stem Cells.
abstract: Thirdhand cigarette smoke (THS) was recently recognized as an environmental health hazard; however, little is known about it effects on cells. Mitochondria are sensitive monitors of cell health and report on environmentally induced stress. We tested the effects of low levels of THS extracted from terry cloth on mitochondrial morphology and function using stem cells with well-defined mitochondria. Concentrations of THS that did not kill cells caused stress-induced mitochondrial hyperfusion (SIMH), which was characterized by changes in mitochondrial morphology indicative of fusion, increased mitochondrial membrane potential (MMP), increased ATP levels, increased superoxide production, and increased oxidation of mitochondrial proteins. SIMH was accompanied by a decrease in Fis1 expression, a gene responsible for mitochondrial fission, and a decrease in apoptosis-related genes, including Aifm2, Bbc3, and Bid There was also down regulation of Ucp2, Ucp4, and Ucp5, genes that decrease MMP thereby reducing oxidative phosphorylation, while promoting glycolysis. These effects, which collectively accompany SIMH, are a prosurvival mechanism to rescue damaged mitochondria and protect cells from apoptosis. Prolonged exposure to THS caused a reduction in MMP and decreased cell proliferation, which likely leads to apoptosis.
authors.affiliation: *Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, California 92521 Environmental Toxicology Graduate Program University of California Riverside.
authors.forename: Vasundhra
authors.initials: V
authors.lastname: Bahl
authors.affiliation: *Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, California 92521.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Johnson
authors.affiliation: *Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, California 92521.
authors.forename: Rattapol
authors.initials: R
authors.lastname: Phandthong
authors.affiliation: *Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, California 92521 Bioengineering Interdepartmental Graduate Program, University of California Riverside.
authors.forename: Atena
authors.initials: A
authors.lastname: Zahedi
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Medicine, University of California, San Francisco, California 94243.
authors.forename: Suzaynn F
authors.initials: SF
authors.lastname: Schick
authors.affiliation: *Department of Cell Biology and Neuroscience, University of California Riverside, Riverside, California 92521 talbot@ucr.edu.
authors.forename: Prue
authors.initials: P
authors.lastname: Talbot
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D049109:Cell Proliferation; D002478:Cells, Cultured; D003470:Culture Media; D020869:Gene Expression Profiling; D006801:Humans; D020782:Matrix Metalloproteinases / Q000096:biosynthesis; D008928:Mitochondria / Q000378:metabolism / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000378:metabolism; D010084:Oxidation-Reduction; D016133:Polymerase Chain Reaction; D017382:Reactive Oxygen Species / Q000378:metabolism; D012906:Smoke / Q000009:adverse effects*; D013234:Stem Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D062789:Tobacco Products; D014158:Transcription, Genetic
chemical_list: D003470:Culture Media; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D012906:Smoke; D000255:Adenosine Triphosphate; D020782:Matrix Metalloproteinases
keywords: cigarette; fusion; mitochondria; oxidation; reactive oxygen species.; smoke; stress; thirdhand smoke; tobacco