logging in or signing up Apoptosis Introduction mahmouda100 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 9575 Category: Education License: All Rights Reserved Like it (6) Dislike it (0) Added: April 03, 2008 This Presentation is Public Favorites: 4 Presentation Description No description available Comments Posting comment... By: Omesh (22 month(s) ago) this is cool bro..... Saving..... Post Reply Close Saving..... Edit Comment Close By: aiza_26 (40 month(s) ago) allow me to download this ppt pls i need it for my reporting allow me untill this saturday pls i beg you all Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript APOPTOSIS: Can the cell be Programmed to suicide ?: APOPTOSIS: Can the cell be Programmed to suicide ?INTRODUCTION: INTRODUCTION Cell death by injury -Mechanical damage -Exposure to toxic chemicals Cell death by suicide -Internal signals -External signalsWhy should a cell commit suicide?: Why should a cell commit suicide? Apoptosis is needed for proper development The resorption of the tadpole tail The formation of the fingers and toes of the fetus The sloughing off of the inner lining of the uterus The formation of the proper connections between neurons in the brain Apoptosis is needed to destroy cells Cells infected with viruses Cells of the immune system Cells with DNA damage Cancer cells Slide4: Importance of Apoptosis Important in normal physiology / development Development: Immune systems maturation, Morphogenesis, Neural development Adult: Immune privilege, DNA Damage and wound repair. Excess apoptosis Neurodegenerative diseases Deficient apoptosis Cancer AutoimmunityWhat makes a cell decide to commit suicide?: What makes a cell decide to commit suicide? Withdrawal of positive (Growth) signals growth factors for neurons Interleukin-2 (IL-2) Receipt of negative (Death) signals increased levels of oxidants within the cell damage to DNA by oxidants death activators : Tumor necrosis factor alpha (TNF-) Lymphotoxin (TNF-β) Fas ligand (FasL)History of cell death / apoptosis research: History of cell death / apoptosis research 1800s Numerous observation of cell death 1908 Mechnikov wins Nobel prize (phagocytosis) 1930-40 Studies of metamorphosis 1948-49 Cell death in chick limb & exploration of NGF 1955 Beginning of studies of lysomes 1965 Necrosis & PCD described 1971 Term apoptosis coined 1977 Cell death genes in C. elegans 1980-82 DNA ladder observed & ced-3 identified 1990 Apoptosis genes identified, including bcl-2, fas/apo1 & p53, ced-3 sequenced (Richerd et.al., 2001)Apoptosis vs. Necrosis: Apoptosis vs. Necrosis Cellular condensation Membranes remain intact Requires ATP Cell is phagocytosed, no tissue reaction Ladder-like DNA fragmentation In vivo, individual cells appear involved Cellular swelling Membranes are broken ATP is depleted Cell lyses, eliciting an inflammatory reaction DNA fragmentation is random, or smeared In vivo, whole areas of the tissue are affected Necrosis ApoptosisApoptosis: Pathways: Apoptosis: PathwaysSlide9: MAJOR PLAYERS IN APOPTOSIS Caspases Death signals e.g. TNF & TNFR p53 BAX Bcl-2 family CONCLUSION: CONCLUSION an important process of cell death can be initiated extrinsically through death ligands (e.g. TRAIL, FasL) activating initiator caspase 8 through induced proximity. can be initiated intrinsically through DNA damage (via cytochrome c) activating initiator caspase 9 through oligomerization. Initiator caspases 8 and 9 cleave and activate effector caspase 3, which leads to cell death.Slide12: The bcl-2 family Receptor domain phosphorylation Raf-1 calcineurin Pore formation Membrane anchor Ligand domainSlide13: P53 & Apoptosis p53 is an unstable tumor suppressor protein. It is and acts via zinc finger DNA binding model. It arrests cell growth between G1 S, thus DNA repair can take place. p53 production of CIP(p21) CDKs inhibition Cell cycle stop. Slide14: 3 mechanisms of caspase activation a. Proteolytic cleavage e.g. pro-caspase 3 b. Induced proximity, e.g. pro-caspase 8 c. Oligomerization, e.g. cyt c, Apaf-1 & caspase 9 You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Apoptosis Introduction mahmouda100 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 9575 Category: Education License: All Rights Reserved Like it (6) Dislike it (0) Added: April 03, 2008 This Presentation is Public Favorites: 4 Presentation Description No description available Comments Posting comment... By: Omesh (22 month(s) ago) this is cool bro..... Saving..... Post Reply Close Saving..... Edit Comment Close By: aiza_26 (40 month(s) ago) allow me to download this ppt pls i need it for my reporting allow me untill this saturday pls i beg you all Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript APOPTOSIS: Can the cell be Programmed to suicide ?: APOPTOSIS: Can the cell be Programmed to suicide ?INTRODUCTION: INTRODUCTION Cell death by injury -Mechanical damage -Exposure to toxic chemicals Cell death by suicide -Internal signals -External signalsWhy should a cell commit suicide?: Why should a cell commit suicide? Apoptosis is needed for proper development The resorption of the tadpole tail The formation of the fingers and toes of the fetus The sloughing off of the inner lining of the uterus The formation of the proper connections between neurons in the brain Apoptosis is needed to destroy cells Cells infected with viruses Cells of the immune system Cells with DNA damage Cancer cells Slide4: Importance of Apoptosis Important in normal physiology / development Development: Immune systems maturation, Morphogenesis, Neural development Adult: Immune privilege, DNA Damage and wound repair. Excess apoptosis Neurodegenerative diseases Deficient apoptosis Cancer AutoimmunityWhat makes a cell decide to commit suicide?: What makes a cell decide to commit suicide? Withdrawal of positive (Growth) signals growth factors for neurons Interleukin-2 (IL-2) Receipt of negative (Death) signals increased levels of oxidants within the cell damage to DNA by oxidants death activators : Tumor necrosis factor alpha (TNF-) Lymphotoxin (TNF-β) Fas ligand (FasL)History of cell death / apoptosis research: History of cell death / apoptosis research 1800s Numerous observation of cell death 1908 Mechnikov wins Nobel prize (phagocytosis) 1930-40 Studies of metamorphosis 1948-49 Cell death in chick limb & exploration of NGF 1955 Beginning of studies of lysomes 1965 Necrosis & PCD described 1971 Term apoptosis coined 1977 Cell death genes in C. elegans 1980-82 DNA ladder observed & ced-3 identified 1990 Apoptosis genes identified, including bcl-2, fas/apo1 & p53, ced-3 sequenced (Richerd et.al., 2001)Apoptosis vs. Necrosis: Apoptosis vs. Necrosis Cellular condensation Membranes remain intact Requires ATP Cell is phagocytosed, no tissue reaction Ladder-like DNA fragmentation In vivo, individual cells appear involved Cellular swelling Membranes are broken ATP is depleted Cell lyses, eliciting an inflammatory reaction DNA fragmentation is random, or smeared In vivo, whole areas of the tissue are affected Necrosis ApoptosisApoptosis: Pathways: Apoptosis: PathwaysSlide9: MAJOR PLAYERS IN APOPTOSIS Caspases Death signals e.g. TNF & TNFR p53 BAX Bcl-2 family CONCLUSION: CONCLUSION an important process of cell death can be initiated extrinsically through death ligands (e.g. TRAIL, FasL) activating initiator caspase 8 through induced proximity. can be initiated intrinsically through DNA damage (via cytochrome c) activating initiator caspase 9 through oligomerization. Initiator caspases 8 and 9 cleave and activate effector caspase 3, which leads to cell death.Slide12: The bcl-2 family Receptor domain phosphorylation Raf-1 calcineurin Pore formation Membrane anchor Ligand domainSlide13: P53 & Apoptosis p53 is an unstable tumor suppressor protein. It is and acts via zinc finger DNA binding model. It arrests cell growth between G1 S, thus DNA repair can take place. p53 production of CIP(p21) CDKs inhibition Cell cycle stop. Slide14: 3 mechanisms of caspase activation a. Proteolytic cleavage e.g. pro-caspase 3 b. Induced proximity, e.g. pro-caspase 8 c. Oligomerization, e.g. cyt c, Apaf-1 & caspase 9