Apoptosis_Presentation.pptx.dr.sana.khurram

apoptosis by robins pathology

1. Apoptosis Based on Robbins Pathology Your Name / Institution (Optional)

2. Introduction to Apoptosis - Definition: Programmed cell death, essential for maintaining homeostasis - Physiological vs. Pathological Apoptosis - Importance in Development and Disease Prevention

3. Morphological Features of Apoptosis - Cell shrinkage - Chromatin condensation (pyknosis) - Nuclear fragmentation (karyorrhexis) - Membrane blebbing - Formation of apoptotic bodies

4. Biochemical Features - Activation of caspases (cysteine proteases) - DNA fragmentation (ladder pattern) - Phosphatidylserine externalization - Lack of inflammation (vs. necrosis)

5. Apoptotic Pathways - **Intrinsic (Mitochondrial) Pathway** - Role of Bcl-2 family - Cytochrome c release & apoptosome formation - Caspase-9 activation - **Extrinsic (Death Receptor) Pathway** - Fas-FasL, TNF receptor interactions - Caspase-8 activation

6. Execution Phase of Apoptosis - Common final pathway - Activation of executioner caspases (Caspase-3, -6, -7) - Cleavage of cellular components

7. Apoptosis vs. Necrosis | Feature | Apoptosis | Necrosis | |-------------|----------|----------| | Cell size | Shrinks | Swells | | Inflammation | No | Yes | | DNA pattern | Ladder | Random | | Energy-dependent | Yes | No |

8. Physiological & Pathological Roles **Physiological:** - Embryogenesis (digit separation) - Immune system regulation - Hormone-dependent tissue involution **Pathological:** - Cancer (resistance to apoptosis) - Neurodegenerative diseases - Autoimmune diseases

9. Apoptosis and Cancer - Role of p53 in apoptosis induction - Tumor evasion by inhibiting apoptosis - Therapeutic targeting (Bcl-2 inhibitors, caspase activators)

10. Summary and Conclusion - Apoptosis is a tightly regulated process - Essential for normal development and disease prevention - Dysregulation leads to various diseases - Potential therapeutic applications in medicine

11. References - Robbins and Cotran Pathologic Basis of Disease (Latest Edition) - Scientific articles and reviews on apoptosis