Lecture 25 Cell Death and Aging

Lecture 25 Cell Death and Aging - IPHY 3060 Lecture 27:...

Info iconThis preview shows pages 1–21. Sign up to view the full content.

View Full Document Right Arrow Icon
IPHY 3060 Lecture 27: Cell Death and Aging
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Apoptosis or Regulated Cell Death
Background image of page 2
Apoptosis or Regulated Cell Death: The regulated process by which unneeded or damaged cells are eliminated from a multicellular organism
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Regulated cell death is a necessary component of multicellular organisms Pruning of cells formed during development to shape organs and structures Elimination of damaged or defective cells so they don’t become dangerous
Background image of page 4
Examples of Apoptosis During Development Removal of cells between the fingers Deletion of embryonic tail Pruning of neuronal connections Elimination of immune cells that recognize self
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Apoptosis and Disease Excessive apoptosis—tissue involution and atrophy Insufficient apoptosis—cancer, atherosclerosis, autoimmune diseases
Background image of page 6
Features of Apoptosis Cell shrinkage and convolution
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Features of Apoptosis Nuclear Fragmentation Cell fragmentation
Background image of page 8
Features of Apoptosis Engulfment of apoptotic bodies by neighboring cells
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Examples of apoptotic cells
Background image of page 10
Show video, Apoptosis
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Necrosis: “Accidental” cell death that occurs when a cell is chemically or physically damaged
Background image of page 12
Apoptosis vs. Necrosis “Programmed cell death” Requires signaling and gene expression Cell shrinkage Cell fragments into apoptotic bodies No inflammation “Accidental cell death” Does not require signaling and gene expression Cell swelling Cell lyses and bursts, spilling contents Inflammation Apoptosis Necrosis
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Necrosis is characterized by swelling and lysis of cells
Background image of page 14
Apoptosis is a Regulated Process Requires cell- cell communication Requires active gene expression
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Apoptosis and Cell-Cell Communication All cells require survival or trophic factors to keep them from dying Some cells provide “death” signals which “murder” other cells Communication can be either via secreted factors or cell-cell contact
Background image of page 16
Apoptosis and Gene Expression Killer proteins are required to initiate the apoptotic process Destruction proteins break down the cell Engulfment proteins are required for phagocytosis of a dying cell by another cell Killer proteins Destruction proteins apoptosis Apoptotic cell Neighboring cell Engulfment proteins engulfment
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Proteins Involved in Apoptosis Bcl-2/Bax family members —”killer” proteins--anti- and pro-apoptotic members which regulate cell death Caspases —”destruction” proteins-- proteolytic enzymes that cleave intracellular proteins
Background image of page 18
Steps Involved in Apoptosis Bcl-2 ordinarily binds to and inactivates Bax
Background image of page 19

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Steps Involved in Apoptosis Bcl-2 ordinarily binds to and inactivates Bax In response to an apoptotic signal, Bad binds to Bcl-2, inactivating it Mitochondrial membrane
Background image of page 20
Image of page 21
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 53

Lecture 25 Cell Death and Aging - IPHY 3060 Lecture 27:...

This preview shows document pages 1 - 21. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online