It is programmed cell death in which a series of biochemical events that lead to a variety of morphological changes such as changes to the cell membrane like the loss of membrane asymmetry and attachment, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation (1-4). In this process the cell is able to dispose of cellular debris that would otherwise result from necrosis in order protect the surrounding from damage.
B, assessment of cell death by lactate dehydrogenase (LDH) release into the medium, posttransfection (Hossain et al, JBC, 2003)
Causes ER Stress by blocking the ability of cell from pumping calcium into the endoplasmic reticulum Low level of calcium prevent the folding chaperones from folding the proteins properly Results in the production of pro-apoptotic genes like chop and TDAG 51 that trigger apoptosis
Cell Culture Techniques: Changing the media Passage the cells Cell counting (5.0 x 10 5 cells/mL) Preparing the Six Well Plate ◦ Plated and left over night to grow ◦ Changed media to 1 % fbs 1 x Antibiotics Treatment ◦ Treated with DMSO (veh.), 1 µM Thapsigargin ◦ Another well was treated with 1 % Triton X for 100 % cell death control
Gathering the Results: Lactate dehydrogenase (LDH) Assay ◦ Quantifies the amount of cell death in sample ◦ Chlorometric assay ◦ Analysis sample under 492 nm of light to measure the amount of cell death ◦ Not a measure of programmed cell death (apoptosis)
Western Blotting essential part of this experiment Verified that the TDAG (T-Cell Death Associated Gene 51) 51 gene was not present in the Tdko cells Allowed to measure GRP 78 (ER chaperone) CHOP (other pro-apoptotic ER stress response gene)
TDAG51 -actin TDAG51 +/+ TDAG51 -/- TDAG51 Expression in Mouse Embryonic Fibroblast used for Experiments
The results from this experiment suggest that TDAG 51 is part of the apoptotic mechanism. It is probably one of the trigger genes because the cells that lacked the gene were able to survive longer than the wild type cells. How exactly does the tdko affect apoptosis? What key role does it play in the mechanism?
We found that the gene TDAG 51 is very important for ER Stress induced cell death at the 24 hour time point. TDAG 51 is likely a pro-apoptotic gene.
Henderson Research Centre Dr. Austin Dr. Dickhout Dr. Hiam Al-Bayati Hill Park Coop Program Mr. Watts