Differentiation of Stem Cells in Dental Follicles

May 1, 2012 By Leave a Comment

Dental follicles are the sacs of loose connective tissue surrounding a tooth that has not yet erupted from the gums. This tissue plays a number of different important roles. For example, it is necessary for a tooth to break through the gums and it regulates the osteogenesis and osteoclastogenesis necessary for tooth eruption.

Dental FolliclesWhen a tooth begins piercing the gingiva, the dental follicle differentiates into the periodontal ligament that anchors the tooth in the socket, securing it to the alveolar bone that surrounds it. In addition, it has been hypothesized that a number of dental follicles differentiate into the tooth’s cementoblasts and some of the alveolar bone’s osteoblasts. Even though some research indicates that some cementoblasts may come from the epithelial root sheath and from the dental follicles, other research suggests all cementoblasts come from dental follicles.

Through the differentiation of stem cells in the dental follicles into cell types other than the periodontal ligament’s fibroblasts, then the stem cells within the dental follicles are creating the additional cell types. It is a well-known fact that adult stem cells are derived from a number of different sources and have the ability to differentiate into other cell types.

It has been proven that adult stem cells are present in the dental follicles of human wisdom teeth, as well as in the dental follicles of mice. In regards to the mice, researchers cloned three dental follicle cell lines with one likely to be the fibroblastic dental follicle cells that form the periodontal ligament, one that was undifferentiated and one that displayed mineralization behavior.

By injecting bovine dental follicle cells into mice with deficient immune systems, cementum formed, which was detected by the anti-cementum attachment protein. Recently, a line of cementoblast progenitor cells from bovine dental follicles was isolated and immortalized.

There were three different objectives to this research. First of all, to determine if the cells are in the rat dental follicles, as seems to be the case with humans, cows and mice. Second, whether the differentiation of stem cells of this type is possible. For instance, the objective is to determine if these stem cells are only able to differentiate into cells that come from mesoderm, or if it is possible for them to differentiate into cell types from other germ layers. Finally, the research should define the properties of the stem cells so that they can be isolated in a manner that is both effective as well as cost efficient.

For studies in the future, especially those that involve the engineering of tissue, stem cells from dental follicles will have to be isolated. The findings appear to get rid of non-stem cells from the population, which may be a way of inexpensively and effectively isolating side-population stem cells, as long as the cells retain the pluripotent phenotype.

Filed Under: Adult Stem Cells, stem cell differentiation, stem cell research, Stem Cells Tagged With: , ,

The Cons of Adult Stem Cell Research

April 26, 2012 By Leave a Comment

A huge controversy exists over stem cell research conducted using cells that come from embryos as well as adult stem cells. Many pro-life organizations argue against stem cell research because the harvesting of embryonic stem cells destroys human life. Therefore, such groups fell that only adult stem cells should be used in research. However, the debate continues since there are also disadvantages to using adult stem cells. These cons of adult stem cells research remains the topic of a number of arguments today.

One argument against the use of adult stem cells is the fact that the cells are of limited quantity. There are less adult stem cells in mature stem cells, which make it more difficult to isolate the cells. This is a major disadvantage, since stem cell replacement therapy requires a large number of cells.

Stem Cell ResearchAnother argument is that adult stem cells are not dependable because they are finite. Because of the age of adult stem cells and the greater possibility for DNA mutations, they may not last long. Researchers are searching for a way to increase the number of cells in culture, but so far all of the results have been failed attempts or inconclusive. Since stem cell therapy requires such great numbers of cells, this is another major disadvantage to using adult stem cells.

Adult stem cells also have limited flexibility because as humans age, they stretch out, which results in a tightening of the stem cells. This diminishes their versatility, which can lead to a number of complications over time. Therefore, replacement therapy is not as conclusive in adult stem cell experiments.

One major downfall to the use of adult stem cells is the fact that they are pre-specialized. This means that stem cells cannot be harvested from just any part of the body and altered to replace specific cells. Adult stem cells only have the ability to reproduce the tissues from which they came. Therefore, muscle cells are only capable of producing muscle cells, blood cells can only make blood and so forth and so on.

The main reason there is such a great focus on the cons of adult stem cells research is that many fear that such disadvantages will lead to more research and experiments with embryonic stem cells; thus, resulting in the destruction of human life. Therefore, many people will argue that stem cells should not be used at all.

However, research on adult stem cells has provided a large number of medical breakthroughs, benefiting patients with all different types of conditions and injuries. This is something that cannot be said about embryonic stem cells. Those who criticize all types of stem cell research should take the time to learn about the many advantages and stop focusing on the cons of adult stem cells research.

Filed Under: Adult Stem Cells, stem cell research, Stem Cells Tagged With: , , , ,

Where Do Stem Cells Come From Exactly?

April 23, 2012 By Leave a Comment

Adult Stem CellsThe use of stem cell treatments is often criticized. The reason for this is that many people do not know the exact answer to the question, “where do adult stem cells come from?” Because the media focuses mainly on the use of embryonic stem cells, which require embryos to be destroyed, most people do not completely understand the benefits of adult stem cells, which are derived from the patient’s body.

According to their source and malleability, all stem cells are different. Just as many differentiated and specialized cells exist in the body, there are also a large number of different stem cells within the body.

Adult stem cells have the important job of replenishing the cells that need to be replaced throughout the body due to normal wear and tear. They are found in specific tissues within the body. Among the most common adult stem cells are hematopoietic stem cells, skin stem cells and neural stem cells.

Hematopoietic stem cells, which are also referred to as blood stem cells are found in bone marrow and umbilical cord blood in addition to the blood. These stem cells are used frequently in standard stem cell treatments because they make new blood cells.

Usually, when a baby is born, the umbilical cord is discarded as biohazardous waste. However, research has found in recent years that the blood from the umbilical cord is a rich source of adult stem cells. The therapies that use these cells are less prone to rejection and have been found to be an effective method for treating leukemia, blood disorders and several types of cancer.

Adult stem cells also come from bone marrow. This type of stem cells is used to repopulate the white blood cells, also known as leukocytes, and bone marrow in patients who are suffering from leukemia. As a matter of fact, hematopoietic stem cells from bone marrow have been used for the past forty years in transplants.

Peripheral blood stem cells are derived from circulating blood. They are used to treat patients who have blood disorders, leukemia and other types of cancer.

Adult stem cells can come directly from the patient who is in need of treatment, or from a donor. However, adult stem cells directly from the patient’s own body are less likely to be rejected.

The question, “where do adult stem cells come from?” was first asked many years ago. Research began on adult stem cells around fifty years ago when researchers made the discovery that bone marrow actually contains at least two different types of stem cells, hematopoietic stem cells and bone marrow stromal stem cells, which are also known as mesenchymal or skeletal stem cells. Stromal stem cells have the ability to generate cartilage, bone and fat cells as well as fibrous connective tissue and cells to support blood formation.

Filed Under: Adult Stem Cells, stem cell research, Stem Cell Treatments and Uses Tagged With: , , , , ,

What Are Stem Cells Used For In This Paraplegic Breakthrough?

April 19, 2012 By Leave a Comment

Adult Stem Cells For Spinal Cord InjuriesWhat are stem cells used for? The resounding answer these days seems to be major medical breakthroughs. In this recent breakthrough, Korean scientists report using adult stem cells derived from umbilical cord blood in order to restore sensation and mobility to patients who have suffered injuries to the spinal cord.

The study was published in Cythotherapy, which is a peer-reviewed journal. It focused on a female patient who had been paralyzed for nineteen years following an accident. Astonishing results were produced after the adult stem cells from umbilical cord blood were infused into the patient’s body.

According to researchers, “The patient could move her hips and feel her hip skin on day 15 after transplantation. On day 25 after transplantation, her feet responded to stimulation.”

At first, some people may be skeptical of this research due to the use of cells from umbilical cord blood. Embryonic stem cells are harvested from human embryos, which are destroyed in the process. However, the stem cells used in this research are adult stem cells, which means no human lives were taken to conduct this study.

The researcher’s report stated that motor activity was apparent at the end of the first week following the procedure. Before the end of the second week, the patient was able to sit upright. Within the first fifteen days, the patient was able to elevate both legs as high as one centimeter.

In addition to regaining feeling, but also according to the study’s abstract, within forty-one days following the stem cell treatment, tests also indicated “regeneration of the spinal cord at the injured site.” Scientists came to the conclusion that this type of stem cell transplantation for paraplegic patients “could be a good treatment method”.

In writing for the Lifesite website, bioethics specialist Wesley J. Smith was enthusiastic about this medical breakthrough, but also expressed his concern. The senior fellow at the Discovery Institute in Seattle, Washington, and special consultant to the Center for Bioethics and Culture of Pleasant Hill, California, said, “We have to be cautious.” He continued, “One patient does not a treatment make.”

Smith also wrote that the authors of the study indicate that the laminectomy the patient received could have been beneficial in some way. He said, “But still, this is a wonderful story that offers tremendous hope for paralyzed patients.” He also added that the patient’s injury was very old, which makes the results of the experiment even more dramatic.

Saying that he has been aware of the study for quite a while, Smith said, “but because I didn’t want to be guilty of the same hyping that is so often engaged in by some therapeutic cloning proponents, I waited until it was published in a peer reviewed journal.”

Therefore, if you were to ask the patient in this study, “what are stem cells used for“, she just may reply “miracles”.

 

Filed Under: stem cell research, Stem Cell Treatments and Uses Tagged With: , , , ,

Advanced Uses of Adult Stem Cells To Replace Bone

April 17, 2012 By Leave a Comment

In a momentous development in regenerative medicine, researchers studying the uses of adult stem cells at Rice University in Houston, Texas, have found a new way to harvest adult stem cells from bone marrow so that the cells produce a growth matrix on their own that is rich in vital biochemical growth factors.

Neha DattaAccording to the research, which is posted online on the Proceeding of the National Academy of Sciences website, this discovery is prominent not only for the science, but also due to the fact that the researcher conducting the study is an undergraduate bioengineering senior. Néha Datta discovered that it is possible to manipulate bone cells into producing as much as seventy-times more calcium than normal.

One researcher working on the project was Antonio Mikos. Mikos is the John W. Cox Professor of Bioengineering as well as the Director of the Center for Excellence in Tissue Engineering at Rice University. According to Mikos, “This is also a notable personal achievement for Néha, because PNAS is one of the top scientific journals in the country and because this is the third peer-reviewed paper – and the second first-authored paper — that she’s produced in the past year.”

This type of regenerative medicine, which is referred to as tissue engineering, involves the harvesting of adult stem cells from the patient and growing new tissues to be transplanted back into the patient’s body with little risk for rejection. The majority of approaches to tissue engineering involve three different components, which are harvesting the adult stem cells, the growth factors related to the differentiation of the adult stem cells in to the right tissue type, such as bone or skin, and a template or porous scaffold that makes it possible to grow the tissues into the proper shape.

According to Mikos, “Finding the right combination of growth factors is always a challenge.” He also said, “It’s not unusual for adult stem cells to progress through a half-dozen or more stages of differentiation on their way to becoming the right tissue – and any missed cue will derail the process. In most cases, engineers have little choice but to take a trial-and-error approach to designing a growth-factor regime.”

For this study on the uses of adult stem cells, the research team touched on the idea of the stem cells creating the correct growth medium on their own. This was accomplished by seeding titanium mesh discs with stem cells to encourage them to create extracellular matrix, which is the calcified deposit responsible for the structural strength of bones.

Then they run a comparison on the non-treated titanium scaffolds and the pre-generated ECM constructs. The calcification rate on the pre-treated surface was much faster and up to seventy-five percent more calcium was created from the tissues in the pre-treated cultures.

Filed Under: stem cell research, Stem Cell Treatments and Uses Tagged With: , ,
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