STEM CELL RESEARCH (ISLAMIC VIEW)
“Stem Cells” are a group of the cells that have the remarkable potential to develop into many different types in the body. Serving as a sort of repair system for the body they can theoretically divide and replenish other cells as long as the person or animal is alive.
Stem cells have potential in many different area of health and medical research. To start with, studying stem cells will help us to understand how they transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are due to problems that occur somewhere in the process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.
Another potential application of stem cells is making cells and tissues for medical therapies. Today, donated organs and tissues are often used to replace those that are diseased or destroyed. Unfortunately, the number of people suffering from these disorders far outstrips the number of organs available for transplantation. Stem cells offer the possibility of a renewable source of replacement cells and tissues to treat myriad diseases, conditions, and disabilities including Parkinson’s and Alzheimer’s diseases, spinal cord injury, stroke, burns, heart diseases, diabetes, osteoarthritis and rheumatoid arthritis. There is almost no realm of medicine that might not be touched by this innovation.
What is a stem cell?
At the dawn of human life, a sperm fertilizes an egg to create a single cell destined to become a child. As development commences, that cell begins to divide producing after five or six days a small ball of a few hundred cells called a blastocyst. Blastocyst (a pre-implantation embryo), consists of 150 cells: outer cells called trophectoderm and making placenta, and cluster of about 30 cells in the interior called inner cells or embryonic stem cells (ESC) which give rise to the multiple specialized cell type that make up the fetus. There is a fluid filled cavity called blastocell that separates outer cells from inner cells within the blastocyst.
ESC are undifferentiated primitive cells with the ability to a) multiply and renew themselves for long periods (proliferation), and b) differentiate into specific kinds of cells under certain physiologic or experimental condition (differentiation).
Where do the stem cells come from?
a) Embryonic stem cells (ESC), are derived from the inner cell mass of the blastocyst (a very early embryo).
b) Embryonic Germ Cells (EGC), are collected from fetal tissue at a somewhat later stage of development (from a region called the gonadal ridge).
c) Adult stem cells (ASC), are derived from mature tissue. Even after complete maturation of an organism, cells need to be replaced (blood, muscle, connective tissue and to a lesser degree nervous system cells).
What classes of stem cells are there?
a) Totipotent stem cells are cells that can give rise to a fully functional “organism” as well as to every cell type of the body (fertilize egg).
b) Pluripotent stem cells are capable of giving rise to virtually any “tissue” type but not to a functioning organism (ESC).
c) Multi potent stem cells are more differentiated cells and thus can give rise only to a limited number of tissues (adult stem cells).
Knowledge about stem cell science and potential application has been accumulating for more than 30 years. In the 1960’s it was recognized that certain mouse cells had the capacity to from multiple tissue types, and the discovery of bona fide stem cells from mice occurred in 1971. In 1998 teams at University of Wisconsin under leadership of James A. Thomson and at John Hopkins University under leadership of John Gearhart, reported on how to culture the human ESC’s, launching a new era of cell engineering.
Procedure for generating human ESC are as follows:
1. Culture blastocyst
2. Remove outer layer
3. Add chemical to desegregate inner cell mass
4. Transfer inner cell mass to a new well
5. Add selective differentiation factors
6. Deliver differentiated cells to damaged tissue
Discovering the signals that induce the formation of specific cell types has been a very difficult task that is still ongoing. Some methods available to control differentiation of ESC’s, in order to obtain specific cell groups examples are:
a) Changing the chemical composition of the culture medium.
b) Altering the surface of the culture disk.
c) Modifying the cells by inserting specific genes. Leukemia inhibiting factor is the key biological agent.
Scientific arguments against the use of ESG as a treatment for disease and injuries are as follows:
a) Immunological issues causing rejection of transplanted cells.
b) Failing to replicate the full range of normal developmental factors in a culture dish.
c) Lack of sufficient evidence from animal studies to warrant a move to human experimentation.
Solution to the problem of immune rejections:
a) Genetic engineering of ESC’s to alter their immune characteristics,
b) Therapeutic cloning
c) Embryo banking
d) Using patients own adult stem cells
Adult Stem Cells (ASC)
From post-embryonic development through the normal life of any organism, certain tissues of the body require stem cells for normal turnover and repair. The most well-known example of ASC are hematopoietic stem cells of blood. More recently, mesenchymal stem cells (MSC) required for the maintenance of bone, muscle, and other tissues have been discovered. ASC’s are multi potent, they are restricted and unable to generate full range of mature cell types. However, the MSC is in fact an excellent example of the potential for use of stem cells in human therapeutic procedures ASC are capable to differentiating into:
a) Hematopoietic stroma cell give rise to all types blood cells.
b) Bone marrow stromal cells give rise to osteocytes, chrondocytes, adipocytes, etc.
c) Neural stromal cells give rise to neurons, astrocytes, and oligofendrocytes.
d) Epithehial ACS in the lining of digestive tract give rise to goblet cells etc.
e) Skin ACS give rise to keratinocytes, hair follicles and to epidermis.
MSC’s are capable of differentiating into bone, cartilage, muscle, fat and a few other tissue types. Their use for bone and cartilage replacement into undergoing FDA approved clinical trials at the present time.
Certain ACS are pluripotent and could differentiate into multiple cell types for example:
a) Hematopoietic ACS into three major types of brain cells.
b) Bone marrow stromal cells into cardiac and skeletal muscles.
c) Brain ASC into blood and skeletal muscle cells. This ASC capability is called “PLASTICITY,” if the mechanism that is responsible for ASC plasticity can be identified and controlled, existing stem cells from a healthy tissue might be used to repair a diseased tissue.
Adult-derived stem cell therapies will complement, but cannot replace, therapies that may be eventually obtained from ES cells. They do have some advantages. For example, adult stem cells offer the opportunity to utilize small samples of adult tissues to obtain an initial culture of a patient’s own cells for expansion and subsequent implantation (this is called an autologous transplant). This process avoids any ethical or legal issues concerning sourcing and also protects the patient from viral, bacterial, or other contamination from another individual. With proper manufacturing, quality control and testing, allogenic adult stem cells (cells from a donor) may be practical as well. Already in clinical use are autologous and allogenic transplants of hematopoietic stem cells that are isolated from mobilized peripheral blood or from bone marrow by positive selection with antibodies in commercial devices. In general, there is less ethical concern over their initial source. Additionally, since they normally differentiate into a narrower set of cell types, directing them to a desired fate is more straightforward. However, many cells of medical interest cannot, as of yet, be obtained from adult-derived cell types. Production of large numbers of these cells is much more difficult than is the case for ESC’s cells. Based upon our present knowledge base, it appears unlikely than human adult stem cells alone will provide all of the necessary cell types required for the most clinically important areas of research.
Therapeutic Cloning “Embryo Cloning”:
The goal is the harvest stem cells for research and to tract disease. The following steps are taken:
1) Eggs are collected from women’s ovaries (donor).
2) Egg nucleus is removed with a needle.
3) Nucleus of a mature skin cell of the individual in need of an organ (recipient) would be extracted.
4) The nucleus of the recipient then would be introduced into the cytoplasm of the donor enucleated egg.
5) After the egg containing the patients DNA start to divide ESC would be harvested.
6) The ESC’s then cultured, differentiated, and used to generate an organ or tissue that is a genetic match to the recipient.
The clinical potential for stem cell products:
The economic and psychological tolls of chronic, degenerative, and acute diseases in the United States are enormous. It had been estimated that up to 128 million people suffer from such diseases; thus, virtually every citizen is effected directly or indirectly. The total cost of treating diabetes, for example is approaching $100 billion in the United States alone. As more research takes place, the developmental potential of different kinds of stem cells will become better understood. As the science is understood now, adult stem cells are limited in their potential to differentiate. Embryonic germ cells have a great differentiation capacity, and embryonic stem cells are thought to be able to differentiate into almost any tissue. Thus, different types of stem cells could have different applications.
Some examples of treatments for major disease. Type I diabetes in children, nervous system disease (Parkinson’s, Alzheimer’s, etc), primary immunodeficiency, diseases of bone, cartilage, and cancer.
In August 2001, President Bush approved the use of federal funds to support research on a limited number of existing ESC lines. Federal funding to a limited number of cell lines will hamper the progress of science. Those opposed insist that any use of cells derived from human embryo constitutes a significant break of moral principles. Such arguments frequently ignore or mis-characterize the scientific facts. Every day hundreds of fertilized eggs and or embryos not being used in IVF program are destroyed instead of being used for research. We all hope that the government pays more attention to this vital subject.
1. IVF between husband and wife is Halal (Allowed).
2. Stem Cell Research on Unused Fertilized Eggs are Halal.
Originally published on the website of The Islamic Center of Beverly Hills at http://www.icbh.org/ and reprinted with their permission.