Stem CellsStem Cells

Science and SocietyScience and Society

Stem CellsStem Cells A cell whose job is not A cell whose job is not

yet determined yet determined All other cells in the All other cells in the

body “stem” from these body “stem” from these cellscells

They wait in the body They wait in the body until they get a signal to until they get a signal to DIFFERENTIATE DIFFERENTIATE (gradually change into (gradually change into the desired cell type)the desired cell type)

They can become skin They can become skin cells, RBC’s, nerve cells, cells, RBC’s, nerve cells, skeletal muscle cellsskeletal muscle cells

What are stem cells & why What are stem cells & why are they important?are they important?

Undifferentiated cells that Undifferentiated cells that renew themselves over long renew themselves over long periods through cell divisionperiods through cell division

Under certain conditions, Under certain conditions, these cells will differentiate these cells will differentiate and become functioning body and become functioning body cells such as muscle or cells such as muscle or neuronsneurons

A 3-5 day embryo (blastocyst) A 3-5 day embryo (blastocyst) has a group of 30 or more has a group of 30 or more cells that will become all the cells that will become all the cells of the body (all cells cells of the body (all cells stem from these)stem from these)

Scientists hope to use these Scientists hope to use these cells to treat diseasescells to treat diseases

What are the unique What are the unique properties of all stem cells?properties of all stem cells? They are unspecialized (can become They are unspecialized (can become

any type of cell)any type of cell) Capable of dividing and renewing Capable of dividing and renewing

themselves indefinitlythemselves indefinitly

What are embryonic What are embryonic stem cells?stem cells?

Cells derived from Cells derived from embryos that are embryos that are created in vitrocreated in vitro

One blastocyst can One blastocyst can yield millions of yield millions of cellscells

Pluripotent…can Pluripotent…can develop into any develop into any type of celltype of cell

Cells from cultures Cells from cultures can be frozen and can be frozen and shipped to other shipped to other labs for researchlabs for research

What are adult stem What are adult stem cells?cells?

Only certain tissues are thought to contain Only certain tissues are thought to contain stem cells (skin, bone marrow, brain, blood stem cells (skin, bone marrow, brain, blood vessels, liver, and skeletal muscle)vessels, liver, and skeletal muscle)

These stem cells divide but remain inactive These stem cells divide but remain inactive until triggers (like an injury) prompt them until triggers (like an injury) prompt them to differentiateto differentiate

These cells will only become certain types These cells will only become certain types of cellsof cells

Difficult to grow in a petri dish, making it Difficult to grow in a petri dish, making it difficult to develop large #’s of these cellsdifficult to develop large #’s of these cells

What are some potential What are some potential uses of stem cells?uses of stem cells?

Research to Research to determine the determine the signals that result in signals that result in differentiationdifferentiation

Developing ways to Developing ways to manipulate genes, manipulate genes, turning some on and turning some on and offoff

Generating cells and Generating cells and tissues that can be tissues that can be used for treatment used for treatment of injury or diseasesof injury or diseases

What are some ethical What are some ethical issues surrounding stem issues surrounding stem

cell research?cell research? Should human Should human

embryos be embryos be experimented on?experimented on?

Is a blastocyst a Is a blastocyst a human being?human being?

Who should Who should benefit from the benefit from the research?research?

Should the Should the government fund government fund the research?the research?