Stem Cells

What is a stem cell? What is a stem cell? Where do stem cells come from? Where do stem cells come from?

What is a stem cell? A stem cell is a cell that: A stem cell is a cell that: Is unspecialized Is unspecialized Is capable of dividing and renewing itself for a long period of time Is capable of dividing and renewing itself for a long period of time Can give rise to specialized cells Can give rise to specialized cells

There are 3 types of stem cells 1. Totipotent Formed from sperm and egg, has the potential to make every cell in the body and the placenta. Formed from sperm and egg, has the potential to make every cell in the body and the placenta. This cell exists for only 5 days following fertilization This cell exists for only 5 days following fertilization

2. Pluripotent Found between 5-10 days of embryo growth, the embryo is now called a blastocyst Found between 5-10 days of embryo growth, the embryo is now called a blastocyst These cells have the potential to create every cell in the body These cells have the potential to create every cell in the body These cells can be isolated from the inner cell mass (30 cells) of the of the blastocyst These cells can be isolated from the inner cell mass (30 cells) of the of the blastocyst These are called embryonic stem cells and are used for stem cell research These are called embryonic stem cells and are used for stem cell research

Picture of Blastocyst

How big is a blastocyst?

3. Multipotent Called Adult Stem Cells Called Adult Stem Cells Can become a limited number of other cells Can become a limited number of other cells Occur in limited numbers Occur in limited numbers May contain DNA damage from aging, radiation, sunlight, toxins and random mutations that occurred during life May contain DNA damage from aging, radiation, sunlight, toxins and random mutations that occurred during life

Embryonic v. Adult Stem Cells Embryo Come from embryos that are fertilized in petri dishes to be used for couples that cannot conceive, there are 40,000+ being stored currently Come from embryos that are fertilized in petri dishes to be used for couples that cannot conceive, there are 40,000+ being stored currently Could also be created by joining egg/sperm Could also be created by joining egg/sperm Can become every cell type found in the body Can become every cell type found in the body Adult Come from babies, umbilical cords, adults Come from babies, umbilical cords, adults Can become some cell types Can become some cell types Found in some body tissues – brain, bone marrow, blood, eye, fat, muscle, skin and liver Found in some body tissues – brain, bone marrow, blood, eye, fat, muscle, skin and liver

First Stem Cells The first successful stem cells were reported in November of 1998 by a research at the Univ. of Wisconsin who removed the cells from spare embryos at a fertility clinic. He was then able to have these stem cells kept alive without specializing in a petri dish. The first successful stem cells were reported in November of 1998 by a research at the Univ. of Wisconsin who removed the cells from spare embryos at a fertility clinic. He was then able to have these stem cells kept alive without specializing in a petri dish.

Stem Cell Lines After the stem cells are harvested they must be kept healthy and live for many generations without differentiating into specialized cells. After the stem cells are harvested they must be kept healthy and live for many generations without differentiating into specialized cells. This is called a stem cell line. This is called a stem cell line. Cells are then taken from these and used for various research projects. Cells are then taken from these and used for various research projects.

What can embryonic stem cells be used for? Learn how a cell becomes specialized Learn how a cell becomes specialized Be used to test new drugs – decreases amount of animal testing, cheaper, faster, and safer for human trials. Be used to test new drugs – decreases amount of animal testing, cheaper, faster, and safer for human trials. Study causes of disease – lead to possible treatments. Study causes of disease – lead to possible treatments. Study how diseases spread – ex: Bird flu Study how diseases spread – ex: Bird flu

Repair damaged cells – paralysis and spinal cord damage. Repair damaged cells – paralysis and spinal cord damage. Cure diseases – diabetes, heart disease, parkinson’s disease, alzheimer’s disease, genetic diseases etc. Cure diseases – diabetes, heart disease, parkinson’s disease, alzheimer’s disease, genetic diseases etc. Grow into new human organs Grow into new human organs

The controversy Embryonic stem cells are controversial because to obtain them they must destroy the embryo. Embryonic stem cells are controversial because to obtain them they must destroy the embryo. People question where the embryos will come from, how many embryos will have to be destroyed, what are the rights of the embryo? People question where the embryos will come from, how many embryos will have to be destroyed, what are the rights of the embryo?

What can adult stem cells be used for? Have been used successfully for the following: Have been used successfully for the following: Heart disease – inject new cells into heart after heart attacks to replace damaged cells Heart disease – inject new cells into heart after heart attacks to replace damaged cells Leukemia/Cancer – use stem cells from bone marrow Leukemia/Cancer – use stem cells from bone marrow Rheumatoid arthritis – make new cartilage Rheumatoid arthritis – make new cartilage Parkinson’s disease – make new cells Parkinson’s disease – make new cells Type I diabetes – make new pancreas cells Type I diabetes – make new pancreas cells

Past Policies On August 9 th, 2001 President Bush announced that federal funds can be used for human embryo research IF: On August 9 th, 2001 President Bush announced that federal funds can be used for human embryo research IF: The cells were harvested from the embryo before this date The cells were harvested from the embryo before this date The embryo was created for reproductive purposes and was no longer needed The embryo was created for reproductive purposes and was no longer needed The embryo was donated and the donors consented and did not receive any money The embryo was donated and the donors consented and did not receive any money

What did that mean? Any stem cell lines that were already in progress could be used but no stem cells could be harvested if the project receives any federal money. Any stem cell lines that were already in progress could be used but no stem cells could be harvested if the project receives any federal money. Research can be done with private or state funding – exs: California, Harvard Research can be done with private or state funding – exs: California, Harvard

New Policy On March 9 th, 2009 President Obama announced that federal money would be used to continue stem cell research. On March 9 th, 2009 President Obama announced that federal money would be used to continue stem cell research. This lifted many of the bans that had been in place previously and opened up stem cell research to many more scientists and institutions. This lifted many of the bans that had been in place previously and opened up stem cell research to many more scientists and institutions.

President Obama 3/09 “I will ensure that my administration never opens the door to cloning for human reproduction.” “It is dangerous, profoundly wrong and has no place in our society or any society.” President Obama 3/09 “I will ensure that my administration never opens the door to cloning for human reproduction.” “It is dangerous, profoundly wrong and has no place in our society or any society.”

Ethical Debate Are the rights of the embryo more or less important than the people who could benefit from the research? Are the rights of the embryo more or less important than the people who could benefit from the research? Some reports estimate that 100 million Americans suffer from diseases that may be cured using stem cell research. Some reports estimate that 100 million Americans suffer from diseases that may be cured using stem cell research.