Stem Cell Basics

What are stem cells? ounspecialized cells ocan become: o many different kinds of specialized cells

What is differentiation?

unspecialized cell specialized cell Ex- Stem cell nerve liver liver heart cell heart cell etc. etc.

(3) Characteristics of Stem Cells oNot differentiated ofor relatively long periods of time can keep dividing -> unspecialized cells (= long-term self renewal) oWith appropriate signal: o divide -> daughter cells o new daughter cells can differentiate into specialized cells needed for growth and repair into specialized cells needed for growth and repair

What are some different kinds of stem cells? oembryonic ofetal oumbilical cord oadult

Embryonic stem cells oPluripotent- oAbility to differentiate into most cell types oEx: Late Embryonic stem cells

Adult stem cells oMultipotent o usually just differentiates into cell types associated with tissue where stems cells located with tissue where stems cells located oEx: adult stem cells in the brain o -> nerve cells o -> cells important for xmiss of nerve cell signals oPlasticity- some types of adult stem cells may exhibit this o If plastic, then could be considered pluripotent.

Where are stem cells produced? oEmbryonic stem cells o in the inner cell mass of the blastocyst oAdult stem cells o in small numbers in some tissues in the body (bone marrow, brain, skin etc.) o scientists still working to discover origin of adult stem cells

How used in Medicine? Current practical application of stem cell therapy is somewhat limited Adult blood-forming stem cells (found in bone marrow) have been transplanted to treat blood disorders for 40 years Leukemia, lymphoma, other blood disorders Leukemia, lymphoma, other blood disorders

Potential Application of Research Renewable source of organ/tissue replacement need for transplant organs > need for transplant organs > # available donated organs. may be used as “replacement cells”: may be used as “replacement cells”:Alzheimer’sstrokediabetes, arthritis, spinal cord injury, and heart disease

Potential Application of Research Problems in differentiation -> Potential partial cause of: Potential partial cause of:cancer many birth defects Stem cell research will likely lead to better understanding of cell differentiation. Stem cell research will likely lead to better understanding of cell differentiation. Development and testing of new drugs

Some Potential Problems in Applications of Stem Cell Research Immune Rejection Controlling Cell Differentiation

Ethical Issues Protective rights for embryos? Morally acceptable to use stem cells obtained from in vitro fertilization (IVF)? Is stem cell therapy that involves cloning a human cell (therapeutic cloning) morally permissible? How should federal funding be used to support stem cell research? Who will have access to stem cell therapy?

Some Misconceptions about Stem Cell Research Stem cells are currently being used to cure many diseases. Others?