Stem Cell ResearchEssay Preview: Stem Cell ResearchReport this essayStem cellular structures are cells found in most multi-cellular organisms. They are capable of retaining the ability to reinvigorate themselves through mitotic cell division and can differentiate into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s.[1][2] The two broad types of mammalian stem cells are: embryonic stem cells that are found in blastocysts, and adult stem cells that are found in adult tissues. In a developing embryo, stem cells can differentiate into all of the specialized embryonic tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin or intestinal tissues.
As stem cells can be grown and transformed into specialized cells with characteristics consistent with cells of various tissues such as muscles or nerves through cell culture, their use in medical therapies has been proposed. In particular, embryonic cell lines, autologous embryonic stem cells generated through therapeutic cloning, and highly plastic adult stem cells from the umbilical cord blood or bone marrow are touted as promising candidates.[3]
Embryonic stem cellsMain article: Embryonic stem cellEmbryonic stem cell lines (ES cell lines) are cultures of cells derived from the epiblast tissue of the inner cell mass (ICM) of a blastocyst or earlier morula stage embryos.[6] A blastocyst is an early stage embryo—approximately four to five days old in humans and consisting of 50—150 cells. ES cells are pluripotent and give rise during development to all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body when given sufficient and necessary stimulation for a specific cell type. They do not contribute to the extra-embryonic membranes or the placenta.
Nearly all research to date has taken place using mouse embryonic stem cells (mES) or human embryonic stem cells (hES). Both have the essential stem cell characteristics, yet they require very different environments in order to maintain an undifferentiated state. Mouse ES cells are grown on a layer of gelatin and require the presence of Leukemia Inhibitory Factor (LIF).[7] Human ES cells are grown on a feeder layer of mouse embryonic fibroblasts (MEFs) and require the presence of basic Fibroblast Growth Factor (bFGF or FGF-2).[8] Without optimal culture conditions or genetic manipulation,[9] embryonic stem cells will rapidly differentiate.
A human embryonic stem cell is also defined by the presence of several transcription factors and cell surface proteins. The transcription factors Oct-4, Nanog, and SOX2 form the core regulatory network that ensures the suppression of genes that lead to differentiation and the maintenance of pluripotency.[10] The cell surface antigens most commonly used to identify hES cells are the glycolipids SSEA3 and SSEA4 and the keratan sulfate antigens Tra-1-60 and Tra-1-81. The molecular definition of a stem cell includes many more proteins and continues to be a topic of research.[11]
After twenty years of research, there are no approved treatments or human trials using embryonic stem cells. ES cells, being totipotent cells, require specific signals for correct differentiation – if injected directly into the body, ES cells will differentiate into many different types of cells, causing a teratoma. Differentiating ES cells into usable cells while avoiding transplant rejection are just a few of the hurdles that embryonic stem cell researchers still face.[12] Many nations currently have moratoria on either ES cell research or the production of new ES cell lines. Because of their combined abilities of unlimited expansion and pluripotency, embryonic stem cells remain a theoretically potential source for regenerative medicine and tissue replacement
Today, we offer an introduction to several new and unique options in the field. We have taken several years to develop and certify the most comprehensive line of embryonic stem cells, a single set of 100 pluripotency cells. However, we can now provide you with a unique, fully developed set of ES-derived cells.
This is to give you the complete picture in which ES cell lines arise, allowing you to get on with your research, as well as the process of creating the ultimate stem cell! You’ll experience a rapid, accurate, and unique understanding of how ES cells are actually formed.
(Source: PNAS)
*
1. Invent a new method of the developing of stem cells
This week, researchers at the University of Maryland and the Washington University in St. Louis created an innovative, multi-billion dollar project to create a new way of growing stem cells using a simple and efficient way.
The project was an attempt by researchers at the University of Maryland and the U.S. General Medical Research Agency to demonstrate how, through a combination of small (over 100 genes) and high-throughput sequencing, they could grow a large amount of stem cells from a single cell for use exclusively in the next stage of regenerative medicine. They used the results of this study to develop an entirely different type of stem cell approach. These are called stem cells, and their discovery is one that could dramatically reduce the human population, eliminate the need for an expensive blood transfusion and pave the way for new treatments for diseases such as Alzheimer or Parkinson’s: cancer-fighting, new therapies for many disorders are already on the market.
The lab’s program of development was completed by researchers at the University of Maryland’s University of Washington, and it was awarded the 2011 National Science Foundation Grant under the direction of Dr. John Gurdjie, a postdoctoral scholar with National Center for Astrophysics.
2. Improve the efficiency of the development of stem cells
As the discovery of ES cells was first announced in 1997, they soon became the standard of research and development. Over the next two years, researchers in the field developed many more ways to develop a whole organism.
Through the use of an approach developed by University of Maryland PhD student Dr. Robert Van Den Desjardins, and his collaborator Dr. J.S. Smith of the University of Maryland, the team developed the first use of ES cells from a single nucleus for the production of a stem organism. They then applied it directly to the liver, with a single DNA molecule.
It is estimated that the amount of new genetic material derived from ES cell lines in the coming years will reach a new level of 400-500 megabases—enough to allow the development of any number of tissues and other organisms without requiring a single genome.
3. Develop new techniques for growing stem cells through the use of genetic engineering
This project is part of a larger effort at the UC Davis Institute of Regenerative Medicine and is funded by the National Institutes of Health.
4. Develop