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Effects of smoking in human lens epithelial cells. Jae-Woong Koh (MD/PhD) 1 , Nang-Hee Song(MD) 1 , Gil-Joong Yoon (MD/PhD) 2 Department of Ophthalmology, Chosun University College of Medicine, Gwangju, Republic of Korea 1 Happy Eye Clinic, Gwangju, Republic of Korea 2 - PowerPoint PPT Presentation
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Jae-Woong Koh (MD/PhD)1, Nang-Hee Song(MD)1, Gil-Joong Yoon (MD/PhD)2
Department of Ophthalmology, Chosun University College of Medicine, Gwangju, Republic of Department of Ophthalmology, Chosun University College of Medicine, Gwangju, Republic of
KoreaKorea1 1
Happy Eye Clinic, Gwangju, Republic of KoreaHappy Eye Clinic, Gwangju, Republic of Korea22
Authors have no financial interest.
Effects of smoking in human lens epithelial cells
Dr. SongDr. Koh Dr. Yoon
Introduction Cadmium A highly toxic chemical material Group I carcinogen in humans by the international agency for Research on
Cancer (IARC, 1993) Two major source
(Cigarette smoking, Food because of its high rate of soil to plant transfer) Accumulated in human bodies because of the Long biological half–life(10-30yrs) Accumulates in various ocular tissues such as lens, retina, ciliary body and
vitreous.
Cadmium & Cataract Elevated cadmium has been reported in cataractous lenses compared to clear
human Lenses (Ramakrishnan et al., 1995; cekic, 1998) A significant amount of cadmium in the lenses of smokers of chronic smokers
(Mosad et al., 2010:Ramakrishnan et al. , 2010) The smokers exhibit early cataract formation (Claytin et al., 1984)
Introduction P53 The tumor suppressor gene is activated upon DNA damage and it is accumulated in
the nucleus, where it then functions as transcription regulator of for its downstream
target gene.
Caspases A family of cysteine–dependent aspartate directed proteases, play critical
role in the initiation and execution of apoptosis. Two major pathway for caspases activation (extrinsic and intrinsic path ways)
(1) The extrinsic pathway involves the ligation of death receptors resulting in
caspase-8 activation. This initiator caspases activates other caspases
(Caspase 3, 7) referred to as effector caspases.
(2) The intrinsic pathway, In the cytosol, cytochrome c binds to and activates Apaf-1
which itself activates pro caspase-9. Activated caspase- 9 has been shown to
directly cleave and activated the effector protease, caspase-3.
Purpose/MethodPurpose
To investigate the cellular change and cell death mechanism in cultured
human lens epithelial cells induced by smoking.
Method
Cultured lens epithelial cells were challenged with 200, 400, 600, 800, 1000 uM of
cadmium chloride (CdCl2, Catalog No. 202908, Sigma-Aldrich Chemical Co, USA)
for 2 hours, and then were exposed to UV (280-320nm/ 1.2mv/cm2)
The cell viability was evaluated using the microscope and 3-(4,5-dimethylthiazol -2-yl)-
2,5-dipheny tetrazolium bromice (MTT) assay.
The gene and protein level of caspase-8 and P53 were measured after exposed to
CdCl2(600uM) for 2 hours by using RT PCR and western blot.
Result Compared to untreated cell, the cell death increased after Cadmium
chloride exposure in microscopic finding. And MTT assay
demonstrated that the
cell death was increased in proportional to the increased
Cadmium chloride concentration.
The expression of caspase-8 and P53 level all increased after
exposure to cadmium (600 uM ) in RT PCR and western blot.
Result
Photograph of control cells and primary bovine lens epithelial cells
exposed to 800 uM cadmium chloride for 4 hours.
Apoptotic features such as shrinkage of cytoplasm and nuclear fragmentation were
better observed in the cadmium treated group than control group.
Photographed using phase contrast microscopy. Magnification x 100
Control (100X)
4 hr after CdCl2(800uM) treatment (100X)
Result
Effect of cadmium on the viability of HLCEs Dose dependent declined in HLECs viability by cadmium. Serum starved HLECs were incubated with cadmium (0-1000uM) for 24 hr followed by determination of cell viability by MTT assay (Mean ± SD of 3
experiments)
Result
Western blot and Quantitative analysis shows that production of caspase 8 protein in those cell in Increased after Exposure to 600 uM cadmium.
Western blot and Quantitative analysis
shows that production of P53 protein
in those cell in increased after Exposure to 600 uM cadmium.
Caspase 8P53
Control caspase 8 Control P53
Conclusion Our study has successfully shown
Cadmium causes a significant decline in the viability of HLECs in a
dose dependent manner.
Cadmium-induced decrease in cell viability is due to apoptosis in HLECs.
Cadmium-induced apoptosis occurred via the activation of caspases.
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