安徽医科大学：《医学细胞生物学》课程教学资源（课件讲稿，打印版）Programmed cell death and cell senescence

Programmed cell death and cell senescence This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

Section 1.Programmed Cell Death Concept:PCD is the death of a cell in any form, mediated by an intracellular program.PCD is carried out in a regulated process,which usually confers advantage during an organism's life-cycle.PCD serves fundamental functions during both plant and multicellular animal tissue development. Three mechanism of PCD in mammalian cells: Apoptosis Necroptosis(programmed necrosis) Autophagy https://en.wikipedia.org/wiki/Programmed_cell_death2 This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

1090-131=959(cells Sydney Brenner,H.Robert Horvitz,John E.Sulston The Nobel Prize in Physiology or Medicine Nobel 2002. "for their discoveries concerning genetic regulation of organ development and programmed cell death" This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

I.Apoptosis Normal cell Apoptosis:apoptotic bodies 4 This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

1.Concept of apoptosis Apoptosis is a process of PCD that occurs in multicellular organisms.Biochemical events lead to characteristic cell changes(morphology)and death. These changes include blebbing,cell shrinkage,nuclear fragmentation,chromatin condensation,chromosomal DNA fragmentation,and global mRNA decay. Between 50 and 70 billion cells die each day due to apoptosis in the average human adult.For an average child between the ages of 8 and 14,approximately 20 billion to 30 billion cells die a day. This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

2.Morphological and biochemical characteristics of apoptosis Morphological changes: Initiation:Chromatin condensation,cell body shrink; Apoptotic bodies:Chromatin fragmentation,along with some organelles be wrapped by membranes and blebbing from the cells; Phagocytosis:apoptosis bodies be phagocytized by other cells. Mild convolution Nuclear Chromatin fragmentation compaction and Blebbing Apoptotic Phagocytic segregation body cell Condensation of Cell fragmentation cytoplasm Phagocytosis This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

3.Significance of apoptosis Proliferation (mitosis) Increasing Cell number Cell number balance Apoptosis Decreasing Cell number 7 This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

3.Significance of apoptosis Involved in developmental process; Remove unnecessary cells(damaged,infected cells). Aberrant apoptosis: Hyper-:defective immune reaction,many degenerative changes; Hypo-:tumor,autoimmune disease. This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

3.1 Apoptosis during the metamorphosis of a tadpole into a frog This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information

3.2 Sculpting the digits in the developing mouse paw by apoptosis (A) (B) 1mm 10 This document is produced by trial version of Print2Flash.Visit www.print2flash.com for more information