Stem Cell Research Controversy
A stem cell is essentially the building block of the human body. Stem cells are capable of splitting for long periods of time, are unspecialized, but can develop into specialized cells. The earliest stem cells within your body are those located in the human embryo. The stem cells within an embryo will eventually give rise to every cell, tissue and organ in the fetus’s body. Unlike a standard mobile, which could only replicate to make more of its own kind of cell, a stem cell is pluripotent. If it divides, it can create any one of those 220 different cells from your body. Stem cells also have the capacity to self-renew — they can reproduce themselves repeatedly.
There Are Lots of types of stem cells, for example:
Embryonic stem cells – Embryonic stem cells incorporate those found within the embryo, the fetus or the umbilical cord blood. Depending upon when they’re chosen, embryonic stem cells can give rise to any cell in your body.
Adult stem cells – Adult stem cells can be found in babies, children and adults. They reside in developed tissues such as the ones of the heart, kidney and brain. They generally give rise to cells within their resident organs.
Induced pluripotent stem cells (IPSC) – All these stem cells are adult, differentiated cells that have been experimentally”reprogrammed” into a stem cell-like state.
So how do all these types of stem cells operate? And what exactly are their possible uses? Let us find out — beginning with embryonic stem cells.
Once an egg cell is fertilized by a sperm, it is going to split and become an embryo. In the embryo, there are stem cells that are capable of getting all of the a variety of cell kinds of the body. For research, scientists have embryos in two manners. Many couples conceive by the process of in vitro fertilization. Within this process, a couple’s sperm and eggs are fertilized in a dish. The eggs develop into embryos, which are then implanted in the female. However, more embryos are created than can be implanted. Thus, these embryos are usually suspended. Many couples donate their unused embryos for stem cell research.
The second manner by which scientists get embryos is therapeutic cloning. This technique reproduces a mobile (from the individual who needs the stem cell treatment ) using a donor egg. The nucleus is removed from the egg and replaced with the nucleus of the patient’s cell. This egg is stimulated to divide either with power, and the subsequent embryo carries the patient’s genetic material, which significantly lessens the risk that their body will reject the stem cells once they are implanted.
Both methods — using present fertilized embryos and creating fresh embryos specifically for research purposes — are contentious. However, until we get into the controversy, let’s figure out how scientists get stem cells to replicate in a laboratory setting so as to examine them.
When an embryo contains approximately eight cells, the stem cells are totipotent – they could grow into all cell types. At three to five times, the embryo develops into a ball of cells known as a blastocyst. A blastocyst contains about 100 cells total along with the stem cells are indoors. At this point, the stem cells are pluripotent – that they could develop into almost any cell type.
To increase the stem cells, scientists remove them from the blastocyst and culture them (develop them in a nutrient-rich solution) in a Petri dish in the laboratory. The stem cells split several times and scientists split the population into other dishes. After several months, you will find countless stem cells. When the cells continue to grow without differentiating, then the scientists have a stem cell . Cell lines can be suspended and shared between labs. As we’ll see later, stem cell lines are essential for developing treatments.
These days, many expectant mothers are asked about umbilical cord banking — the process of storing umbilical cord blood after giving birth. Why would a person want to accomplish that? After a mom gives birth, the umbilical cord and staying blood are often lost. But this blood also contains stem cells from the fetus. Umbilical cord blood could be harvested along with the embryonic stem cells grown in culture. Unlike embryonic stem cells from before in development, fetal stem cells in umbilical cord blood are multipotent – they can grow into a restricted number of cell types.
It’s possible to think of adult stem cells as our built-in fix kits, regenerating cells damaged by disease, injury and everyday wear and tear. These undifferentiated cells dwell among other differentiated cells in a tissue or organ; they split and be specialized to repair or replace the encompassing differentiated cells. A common example of mature stem cells is hemopoietic stem cells, which can be found in red bone marrow. These stem cells differentiate into various blood cells (red blood cells, lymphocytes, platelets– see Blood Works for more info ). By way of example, red blood cells aren’t capable of repeating and survive for about 28 days. To replace drained reddish blood cells, hemopoietic stem cells in the bone marrow divide and differentiate into new red blood cells.
Bone marrow also includes another kind of adult stem cell called a stromal or mesenchymal stem cell. Stromal stem cells become bone, cartilage, fat and connective cells located in bone. Adult stem cells have also been found in a number of other tissues such as the brain, skeletal muscle, blood vessels, skin, liver, teeth as well as the heart. Irrespective of the source, adult stem cells are multipotent – they could develop into a limited number of cell types.
Although adult stem cells exist in several cells, their numbers are small, perhaps one adult stem cell for every 100,000 surrounding cells. These stem cells look like the surrounding cells, so it’s difficult to tell them apart. But scientists have developed an intriguing way to spot them by”light up them.” All cells have unique proteins on their surface called receptors. Receptors bind chemical messages from different cells as part of cell-to-cell communicating. Researchers use these receptors — or markers — to identify and isolate adult stem cells by”tagging” the chemical messages which bind to those particular receptors on the stem cell together with fluorescent molecules. Once the fluorescent compound message binds to the receptor on the surface of the stem cell, the stem cell will”light up” under fluorescent light. The”lighted” stem cell can then be identified and isolated.
Like embryonic stem cells, adult stem cells can be grown in culture to set up stem cell lines.
Adult stem cells were formerly thought to be more restricted than embryonic stem cells, only giving rise to exactly the same type of tissue from which they originated. But new research indicates that adult stem cells may have the capacity to generate different kinds of cells, as well. For instance, liver cells might be coaxed to produce insulin, which will be normally made from the pancreas. This capability is Called plasticity or even transdifferentiation
It was believed there were only two types of stem cells — embryonic and mature — but there is another kid about the stem cell block. Keep reading to learn about this”fresh” type: the triggered pluripotent stem cell.
Induced Pluripotent Stem Cells (IPSCs)
Whether from embryos or adult cells, stem cells are few. But many are needed for cell therapies. There have been political and ethical difficulties using embryonic stem cells — so if there were a way to get more stem cells from adults, then it may be less controversial. Input the IPSC.
Every cell in the body has the exact same genetic instructions. So what makes a heart cell different from a liver cell? The two cells express distinct sets of genes. Similarly, a stem cell turns on particular sets of genes to differentiate into a different cell. So, can it be possible to reprogram a distinguished cell so that it reverts back into a stem cell? In 2006, scientists did just that. They used a virus to send four stem cell variables into skin tissues. The variables caused the differentiated stem cells to enter an embryonic-stem-cell-like state. The resulting cells, also known as triggered pluripotent stem cells (IPSCs), shared many traits with human embryonic stem cells. The structures of IPSCs were similar, they expressed the very same markers and enzymes, and they grew the same. And the researchers were able to develop the IPSCs into lines.
There are numerous more differentiated cells within the human body compared to stem cells, adult or juvenile. So vast quantities of stem cells can be made from a patient’s own differentiated cells, like skin cells. Making IPSCs does not involve embryos, so this could bypass the ethical and political issues involved in stem cell research. Nevertheless, making ISPSCs is a recent development, so scientists will need to do more research before they may be used for therapies. First, we need to understand that the”reprogramming” process better. And then we need to investigate whether IPSCs are just similar enough or are actually equal to embryonic stem cells. Present research is centered on those questions, but reprogramming cells to create IPSCs has great potential.
Now that you get a good idea of exactly what stems cells are and how they work, let us see how they can be used to treat diseases.
Using Stem Cells to Treat Disease
The initial step in using stem cells for disorder treatment would be to set up stem cell lines, which investigators have accomplished. Next, scientists have to have the ability to turn on particular genes inside the stem cells so that the stem cells will differentiate into any cell they wish. But scientists haven’t learned how to do so however; so, analyzing stem cell differentiation is a lively area of research. Once scientists could produce differentiated cells from stem cells, then there are many possibilities for their use, including drug testing and cell-based remedies. For example, let us say you would like to test new drugs to treat heart diseases. Currently new drugs must be tested on animals. The data from animal research has to be translated and then extrapolated to humans before human clinical trials. But suppose you can test them straight on individual heart cells. To do this, human stem cell lines could be treated to differentiate into human heart cells in a dish. The possible drugs can be tested on these cells and the information would be directly related to humans. This use could save huge amounts of time and money in bringing new drugs to market.
Stem-cell-based remedies aren’t new. The first stem-cell-based therapy was a bone marrow transplant used to treat leukemia. In this process, the patient’s existing bone marrow is destroyed by chemotherapy or radiation. Donor bone marrow is injected to the patient and also the bone marrow stem cells establish themselves in the individual’s bones. The donor bone marrow cells differentiate into blood cells the patient requirements. Many times, the patient must take drugs to stop their immune system from rejecting the bone marrow. However, this procedure uses present hemopoietic stem cells. How would you use stem cell lines? Let us look at how stem cells might be used to treat heart failure.
Ideally, to take care of a failing heart, scientists could stimulate stem cells to differentiate into cells and inject them into the patient’s damaged heart. There, the new heart cells can develop and fix the damaged tissue. Although scientists cannot yet direct stem cells differentiate into cells, they have tested this idea in mice. They’ve injected stem cells (adult, embryonic) into mice with damaged hearts. The cells grew in the damaged heart cells and the mice showed improved heart function and blood circulation.
In such experiments, exactly how the stem cells improved heart function remains contentious. They may have directly regenerated fresh muscle tissues. Instead, they may have stimulated the creation of new blood vessels to the damaged areas. Along with the new blood flow may have stimulated existing heart stem cells to differentiate into new heart muscle cells. These experiments are currently being appraised.
1 major obstacle in stem cell usage is the issue of rejection. When a patient is injected with stem cells obtained from a given embryo, then their immune system may see the cells as foreign invaders and start an assault . Using adult stem cells or IPSCs could conquer this problem somewhat, since stem cells obtained from the individual wouldn’t be reversed by their immune system. But adult stem cells are less flexible than embryonic stem cells and are harder to manipulate in the lab. And IPSC technologies is too new for transplantation work.
Finally, by studying how stem cells differentiate into specialized cells, the information obtained can be used to understand how birth defects occur and potentially, the way to treat them.
So, if there’s so much potential in stem cell research, why all the controversy? Let’s investigate the present ethical and political issues.
Stem Cell Research Controversy
Stem mobile research has come to be among the biggest issues dividing the scientific and religious communities around the world. At the center of the issue is one central question: When does life start? At this moment, to get stem cells that are dependable, scientists either have to work with an embryo that has already been conceived or else clone an embryo by means of a cell from an individual’s body along with a given egg. Either way, to harvest an embryo’s stem cells, scientists must destroy it. Although that embryo might only include five or four cells, some religious leaders say that destroying it’s the equivalent of having a human life. Inevitably, this issue entered the political arena.
In 1996, Congress passed a rider into the national appropriations bill known as the Dickey-Wicker amendment. Representatives Jay Dickey and Roger Wicker proposed prohibiting the use of federal monies for any study in which a human embryo is created or destroyed. Federal monies are a main source of funding for stem cell research. The change has been renewed every year since that time.
In 2001, President George W. Bush further restricted federal stem cell research. In an executive order, Bush said that federal funds could only be used for research on human embryonic stem cell lines that had already been established (only 22 cell lines). This prevents investigators from making more embryonic stem cell lines for research.
In 2009, President Barack Obama issued an executive order to expand embryonic stem cell research. Obama’s administration allowed federal funding of embryonic stem cell research when the following conditions applied:
The cell line was one of the 22 in life throughout the Bush administration or was made from embryos that was discarded after in vitro fertilization procedures.
The donors of the embryos were not paid at all.
The donors clearly knew the embryos would be used for study purposes before giving consent.
According to the government, the new policy did not violate the Dickey-Wicker amendment because the money did not fund the production of new embryos (they had already been created by private means) and failed to fund the destruction of them.
In 2009, two researchers from Boston, Dr. James Sherley of the Boston Biomedical Research Institute and Dr. Theresa Fisher of the Ava Maria Biotechnology Company, along with other agencies filed a lawsuit against the authorities. At first, the litigation has been dismissed because the judge ruled that the plaintiffs had no legal standing (i.e. they weren’t affected materially from the new rules). But a court of appeals overturned the initial ruling. Both scientists remained plaintiffs. The scientists claimed that, because they used adult stem cells exclusively in their research, the new rules would increase competition for federal research dollars, thereby affecting their ability to acquire funding. Federal Judge Royce Lamberth maintained the appeals court ruling. He placed an injunction preventing the new rules from moving into place. He maintained that the rules violated the Dickey-Wicker change because embryos must be destroyed in the process of producing embryonic stem cell lines.
Back in September 2010, The New York Times reported that the U.S. Court of Appeals ruled that federal financing of embryonic stem cell research could persist under the new rules while the court considers Judge Lamberth’s judgment. This ruling allows researchers to continue feeding embryonic stem cell cultures, experimenting with mice, and other study activities until this court principles, the U.S. Supreme Court weighs , or Congress passes laws that explains the issues. In the meantime, stem cell research and the careers of stem cell researchers hang on a roller coaster that is legal. Although stem cells have great potential for curing diseases, much work on the science, ethical and legal fronts remains.