THE ROLE OF TUMOR NECROSIS FACTOR RECEPTOR 1 IN THE APOPTOSIS OF RETINAL PIGMENT EPITHELIAL CELLS. POSSIBLE MECHANISM FOR NEUROPROTECTIN D 1 PROTECTION CAUSED BY OXIDATIVE STRESS.
Document Type
Presentation
Start Date
22-10-2010 3:00 PM
End Date
22-10-2010 4:30 PM
Description
Continuous exposure to several stressors, including reactive oxygen species (ROS), damage retinal pigment epithelial (RPE) cells, a component of outer retinal barrier. Preservation of these cells is very crucial for the normal functioning of rode and cone photoreceptor cells, which degeneration underlies in many eye related diseases. Oxidative stress triggers a stereo specific docosahexaenoic acid (DHA) derived messenger Neuroprotectin D1 (NPD1) synthesis, which counteracts TNFa/H20 2 mediated apoptotic damage in RPE.
Tumor necrosis factor alpha (TNFa) a 24kDa protein, when cleaved from the membrane by TNF-alpha converting enzyme (TACE), forms a heterotrimer which exerts its effect through two surface receptors TNFR1 and TNFR2.The first contains cytoplasmic death domain and may directly induce apoptosis. To define the ability of TNF alpha to promote apoptosis in RPE cells, when oxidatively stressed, we generated a stable knockdown human RPE (ARPE-19) cell line using short hairpin RNA (shRNA) targeting TNFR1. Protein expression in TNFR1 deficient cells was 15% when compared with nonspecific shRNA transfected cells, which were used as control. To assess the effect of TNFa both TNFR1 deficient and nonspecific (NS) ARPE-19 cells were grown in six well plates semi-confluent for 72h. Cells were serum starved for 8h before triggering oxidative stress by further incubation with 1O ng/ml of TNFa plus 600 H20 2 during 15h. Hoescht stained apoptotic cell numbers were quantitatively analyzed using Image J software. In TNFR1 deficient cells apoptosis was suppressed when compared with control. Surprisingly this happened both when TNFa was and was not present. This could mean that H20 2 triggered apoptosis involves TNFR1.
As it was previously shown in our laboratory that incubation of ARPE-19 cells with NPD1 prevent apoptosis when cells are stressed oxidatively (Pranab et al. 2004). Also another previous work from our laboratory demonstrates that NPD1 inhibits brain ischemia-reperfusion-induced NF-KB expression (Marcheselli et al., 2003). The last may be involved in TNFa induced apoptosis in the presence of H20 2. Hence it is of interest to define the role of NF-KB involvement in NPD1 prevention of ARPE19 cells.
Recommended Citation
Asatryan, Aram R.; Calandria, Jorgelina M.; and Bazan, N. G., "THE ROLE OF TUMOR NECROSIS FACTOR RECEPTOR 1 IN THE APOPTOSIS OF RETINAL PIGMENT EPITHELIAL CELLS. POSSIBLE MECHANISM FOR NEUROPROTECTIN D 1 PROTECTION CAUSED BY OXIDATIVE STRESS." (2010). Dr. Joseph M. Moerschbaecher, III Graduate Research Day. 1.
https://digitalscholar.lsuhsc.edu/grad_rs/2010/poster2/1
THE ROLE OF TUMOR NECROSIS FACTOR RECEPTOR 1 IN THE APOPTOSIS OF RETINAL PIGMENT EPITHELIAL CELLS. POSSIBLE MECHANISM FOR NEUROPROTECTIN D 1 PROTECTION CAUSED BY OXIDATIVE STRESS.
Continuous exposure to several stressors, including reactive oxygen species (ROS), damage retinal pigment epithelial (RPE) cells, a component of outer retinal barrier. Preservation of these cells is very crucial for the normal functioning of rode and cone photoreceptor cells, which degeneration underlies in many eye related diseases. Oxidative stress triggers a stereo specific docosahexaenoic acid (DHA) derived messenger Neuroprotectin D1 (NPD1) synthesis, which counteracts TNFa/H20 2 mediated apoptotic damage in RPE.
Tumor necrosis factor alpha (TNFa) a 24kDa protein, when cleaved from the membrane by TNF-alpha converting enzyme (TACE), forms a heterotrimer which exerts its effect through two surface receptors TNFR1 and TNFR2.The first contains cytoplasmic death domain and may directly induce apoptosis. To define the ability of TNF alpha to promote apoptosis in RPE cells, when oxidatively stressed, we generated a stable knockdown human RPE (ARPE-19) cell line using short hairpin RNA (shRNA) targeting TNFR1. Protein expression in TNFR1 deficient cells was 15% when compared with nonspecific shRNA transfected cells, which were used as control. To assess the effect of TNFa both TNFR1 deficient and nonspecific (NS) ARPE-19 cells were grown in six well plates semi-confluent for 72h. Cells were serum starved for 8h before triggering oxidative stress by further incubation with 1O ng/ml of TNFa plus 600 H20 2 during 15h. Hoescht stained apoptotic cell numbers were quantitatively analyzed using Image J software. In TNFR1 deficient cells apoptosis was suppressed when compared with control. Surprisingly this happened both when TNFa was and was not present. This could mean that H20 2 triggered apoptosis involves TNFR1.
As it was previously shown in our laboratory that incubation of ARPE-19 cells with NPD1 prevent apoptosis when cells are stressed oxidatively (Pranab et al. 2004). Also another previous work from our laboratory demonstrates that NPD1 inhibits brain ischemia-reperfusion-induced NF-KB expression (Marcheselli et al., 2003). The last may be involved in TNFa induced apoptosis in the presence of H20 2. Hence it is of interest to define the role of NF-KB involvement in NPD1 prevention of ARPE19 cells.
Comments
See abstract book page 45