Apoptosis is a combination of the Greek words apo (off) and ptosis (falling), refers to the blebbing of cell cytoplasm seen at the end of apoptosis, which is also called programmed cell death.
This process can be initiated by many different signaling pathways and is
characterized by cleavage of chromosomal DNA, chromatin condensation, and
finally fragmentation of both the nucleus and the cell. Cell death occurs
by 2 processes Necrosis and Apoptosis. Unprogrammed cell death, Necrosis,
leads to the bursting of a cell and its contents being spilled into the extracellular
space, followed by inflammation.
Apoptosis was a term first coined in 1972, is a series of regulated steps:
modification of cell membrane, DNA condensation and severing, cytoskeleton
dissassembly, followed by "blebbing" cytoplasmic and nuclear contents
into membrane bound fragments, engulfed by macrophages.
This is a field of research that has grown enormously in recent years (now referenced more that 76000 times). The growing interest is not only for its biological relevance in maintaining homeostasis in multicellular organisms, but also for its potential clinical application in regulating cell numbers (both up and down).
In the embryo, we had often thought that regulated proliferation of cells
was soley required for developmental growth. We now realise that programmed
cell death in the embryo is just as important.
The study guides below should be used in the order Brief -> Detailed -> In Depth depending how much time you have for this topic. Note that the information at each level is not duplicated on the next level, so do not go immediately to In Depth work through each level. External Links may open in a new browser window, close or minimise the new window to see the original Study Guide page.
Start
by looking at the key online cell biology textbooks.
These links will give you an introduction to programmed cell death and some images of the process.
Where in development and the adult system does cell death occur? What are the triggers for cell death? What does a dying cell look like?
More detailed online resources introduce key initiators, proteins and pathways
of cell death.
Includes a link to a complete set of lecture slides on apoptosis and links to other online textbooks, multimedia and searching.
What are the signaling pathways for cell death to occur? What cell organelles are involved in cell death? How long does a cell take to die?
The signaling pathways that mediate programmed cell death.
Includes links to review articles, research articles and laboratories.
What are researchers studying now? What are the ways we can identify cell death? What drugs affect cell death? What happens when cell death does not occur?
This page gives some relevant clinical examples
of apoptosis as well as links to OMIM Database examples.
Search NLM Online Textbooks- "apoptosis"
cell cycle, mitosis, meiosis, apoptosis, necrosis, signaling pathways, cancer, mitochondria, cytoskeleton, microtubules, microfilament, Bcl 2, P53, caspase, DNA ladder, death receptor, growth factors, Akt, cytochrome c
Home
Page
About
Project
Project
Maps
Search
Page
Beginnings
Apoptosis
1 Apoptosis
2 Apoptosis
3 Apoptosis
Medicine
Society & Health
Health
Maintenance
Ageing
Science
General
Help
??
Medicine
Homepage
WebCT
NCBI Bookshelf
This page gives an introduction to programmed cell death. Use the study guide or links to look for more information.
Please email Dr Mark Hill if you wish to make a comment about this current project.