title: Cigarette Smoke Extract Causes Injury in Primary Retinal Ganglion Cells via Apoptosis and Autophagy.
abstract: To investigate whether tobacco smoke directly injures retinal ganglion cells (RGCs) and to evaluate the mechanisms of cell death.
  
  
  
  Primary rat RGCs were harvested from 3- or 4-day-old newborn rats and exposed to cigarette smoke extract (CSE). Cell viability was determined by adenosine 5'-triphosphate (ATP) assay. Apoptosis was evaluated by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) and real-time reverse transcription polymerase chain reaction (RT-PCR) for Bcl-2 family. Autophagy was also assessed by Western immunoblots for light chain (LC) 3B.
  
  
  
  When the primary RGCs were exposed to CSE for 2 h, cell viability decreased in a dose-dependent manner, as measured by ATP assay. In the presence of 0.05% CSE, the RGC viability was 77.68% ± 7.60% compared to the control cells; in the presence of 1.0% CSE, viability was 47.48% ± 2.56% of the control cells. As determined by TUNEL, CSE increased the apoptotic RGCs in a dose-dependent manner. In the presence of 0.05% CSE, the apoptosis was 26.55% ± 1.97% of the control cells; in the presence of 2.5% CSE, it was 41.07% ± 3.75% of the control cells. When apoptosis was evaluated using real-time RT-PCR, exposure to 0.05% CSE resulted in significantly increased expression of Bad, Bax, Bcl-2, and Bcl-XL mRNA. When autophagy was assessed by Western immunoblots, exposure to 0.05% CSE significantly increased the expression of LC3B II.
  
  
  
  Our data suggest that CSE directly injures primary RGCs, and both cell death mechanisms of apoptosis and autophagy seem to be related to this CSE-induced RGC damage.
authors.affiliation: a Department of Ophthalmology, Severance Hospital , Institute of Vision Research, Yonsei University College of Medicine , Seoul , Korea.
authors.forename: Kwanghyun
authors.initials: K
authors.lastname: Lee
authors.affiliation: a Department of Ophthalmology, Severance Hospital , Institute of Vision Research, Yonsei University College of Medicine , Seoul , Korea.
authors.forename: Samin
authors.initials: S
authors.lastname: Hong
authors.affiliation: a Department of Ophthalmology, Severance Hospital , Institute of Vision Research, Yonsei University College of Medicine , Seoul , Korea.
authors.forename: Gong Je
authors.initials: GJ
authors.lastname: Seong
authors.affiliation: a Department of Ophthalmology, Severance Hospital , Institute of Vision Research, Yonsei University College of Medicine , Seoul , Korea.
authors.forename: Chan Yun
authors.initials: CY
authors.lastname: Kim
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D015153:Blotting, Western; D002470:Cell Survival; D002478:Cells, Cultured; D053938:DNA Fragmentation / Q000187:drug effects; D004195:Disease Models, Animal; D020287:In Situ Nick-End Labeling; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D012164:Retinal Diseases / Q000139:chemically induced / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000473:pathology*; D012906:Smoke / Q000009:adverse effects*
chemical_list: D012906:Smoke
keywords: Apoptosis; autophagy; cigarette smoke; glaucoma; retinal ganglion cell