Cadmium induces oxidative stress and apoptosis in lung epithelial cells.
Cadmium (Cd) is one of the well-known highly toxic environmental and industrial pollutants. Cd first accumulates in the nucleus and later interacts with zinc finger proteins of antiapoptotic genes and inhibit the binding of transcriptional factors and transcription. However, the role of Cd in oxidative stress and apoptosis is less understood. Hence, the present study was undertaken to unveil the mechanism of action. A549 cells were treated with or without Cd and cell viability was measured by MTT assay. Treatment of cells with Cd shows reduced viability in a dose-dependent manner with IC50of 45 μM concentration. Cd significantly induces the reactive oxygen species (ROS), lipid peroxidation followed by membrane damage with the leakage of lactate dehydrogenase (LDH). Cells with continuous exposure of Cd deplete the antioxidant super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzymes. Further, analysis of the expression of genes involved in apoptosis show that both the extrinsic and intrinsic apoptotic pathways were involved. Death receptor marker tumor necrosis factor-α (TNF-α), executor caspase-8 and pro-apoptotic gene (Bax) were induced, while antiapoptotic gene (Bcl-2) was decreased in Cd-treated cells. Fluorescence-activated cell sorting (FACS) analysis further confirms the induction of apoptosis in Cd-treated A549 cells.
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
K M
KM
Kiran Kumar
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
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Naveen Kumar
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
Rajeshwari H
RH
Patil
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
Rashmi
R
Nagesh
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
Shubha M
SM
Hegde
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
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K
Kavya
b Department of Bioinformatics and Biotechnology , Karnataka State Women's University , Jnanashakthi Campus , Vijayapura , Karnataka , India.
R L
RL
Babu
c Department of Biology and Center for Biotechnology and Biomedical Sciences , Norfolk State University , Norfolk , VA , USA.
Govindarajan T
GT
Ramesh
a Department of Microbiology and Biotechnology , Bangalore University, Jnana Bharathi , Bengaluru , Karnataka , India.
S Chidananda
SC
Sharma
D000072283:A549 Cells; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D002104:Cadmium / Q000633:toxicity*; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism
D000975:Antioxidants; D004785:Environmental Pollutants; D017382:Reactive Oxygen Species; D002104:Cadmium
Apoptosis; Cadmium; FACS; ROS; RT-PCR; SOD