Stem Cell Research

Stem cells have been widely publicized over the last decade as being the key to huge health breakthroughs. While only time will tell just how stem cells will be used in the future, millions of people around the world are either involved in stem cell research or closely monitor it for news of advances.

What are Stem Cells?

Stem cells are found in practically all multi-cellular organisms. Their defining characteristic is that they are able to renew themselves, usually through a process of mitotic cell division. Besides having the ability to renew themselves, stem cells also have the amazing ability to become one of a wide variety of specialized cell types. Outside of nature, these cells can be grown in the laboratory from simple cell cultures, but in most cases they can be difficult to extract for use. Stem cells today are usually generated through therapeutic cloning of stem cells found in either umbilical cord blood or bone marrow.

Two Main Types of Stem Cells

There are two main types of stem cells. They can be classified as being either embryonic stem cells or adult stem cells.

Embryonic Stem Cells

Embryonic stem cells are derived from embryos. These embryos come from eggs that have been fertilized using in vitro fertilization. It should be noted that embryonic stem cells used in research today do not develop from eggs fertilized in a woman’s body. In most cases, embryonic stem cells are taken from mice and grown in a laboratory using cell cultures to conduct research.

Adult Stem Cells

Adult stem cells can be found in developed organisms, usually within the tissue and organs. One of the main tasks for adult stem cells is to replenish and repair specialized cells that are found in the body.

Stem cells from humans develop about four to five days after fertilization and are defined as a blastocyst. A blastocyst is a hollow ball of cells. Blastocysts include three main structures: the blastocoel, the trophoblast and the inner cell mass. The blastocoel is the hollow structure within the ball. The trophoblast is a layer of cells that encircles the blastocyst, and the inner mass consists of about thirty cells.

Important Properties of Stem Cells

Stem cells as previously stated can be differentiated from specialized cells in the human and other mammalian organisms. Stem cells are usually defined when they possess specific properties: this includes self-renewal and potency.

Self-Renewal – Self-renewal is defined as a cell’s ability to go through numerous cell division cycles without changing its state.

Potency – Potency refers to the ability of a stem cell to differentiate into a specialized cell type. There are four types of potencies: they include pluripotent, totipotent, multipotent and unipotent.

Totipotent – These stem cells are derived from the fusion of a sperm cell and an egg cell. It should be noted that only the cells produced from the first few divisions of a fused sperm cell and egg cell (fertilized egg) are totipotent.

Pluripotent – These are embryonic stem cells that are derived from inner mass cells within a bastocyst. Pluripotent cells develop from stem cells that are decedents of totipotent cells.

Multipotent – These are stem cells that can only transform into a small variety of hematopietic cells. These cells include red blood cells, white blood cells, platelets and other varieties of blood cells.

Unipotent – These are considered stem cells, but are only produced as one single variety. However, since unipotent cells have the characteristic of being self-renewing , they are different from other non-stem cell types.

Natural Uses for Stem Cells

Mammalian Development

When a mammal develops, the first and only cell is the zygote which is the sperm and egg that has become one. This single cell starts to divide into more cells. All of these different cells are stem cells that can be turned into any type of cell that the developing mammal needs to be a health organism. These stem cells, as they develop, turn into heart, brain and muscle cells to name but a few of the hundreds of types of cells created.

Tissue Repair

Studies have shown that there are adult stem cells in the human at all times for the purpose of tissue repair. If an individual had damage done to a nerve, studies have shown that, over time, these cells are slowly regenerated using adult stem cells. The body does this naturally, but at a much slower speed, so people don’t tend to notice that it is going on. Stem cells used in organ regeneration has been shown in the heart as well as in the liver and the kidneys. The brain has shown signs of regeneration due to adult stem cells.

Clinical and Research Uses for Stem Cells

The ultimate goal for scientists when culturing stem cells is to create exact copies of cells from a person so that they can use them to repair the organ. For example, while there are adult stem cells naturally repairing, it is typically done at a much slower pace. Therefore, what scientists hope to do is take a stem cell and culture it to become a certain type of specific cell. An example of this would be to take a stem cell and culture it into becoming a kidney cell because of renal failure.

The following are the three diseases that have already begun to benefit from Stem Cell Research:

• Heart Disease: As heart cells begin to die, the heart becomes weaker. By using stem cells, they can create more heart cells and allow the heart to stay strong.
• Diabetes: By creating beta cells in the pancreas, an individual with diabetes can potentially combat type 1 diabetes because there is insulin consistently being developed.
• Parkinson’s Disease: By creating new dopamine secreting neurons, scientists hope that they’ll be able to take a patient with severe Parkinson’s and allow them to regain control.

Scientists hope that, as time goes on and more research is conducted on stem cells, that they’ll be able to find new and innovative ways of treating people with otherwise life-threatening ailments.