iconimg Monday, May 04, 2015

Indo-Asian News Service
London, May 31, 2010
For the first time, human embryonic stem cells have been cultured under chemically controlled conditions without using animal proteins, making way for harvesting large quantities of stem cells to treat diseases. The method has been developed by researchers at Karolinska Institutet, in Stockholm, one of the foremost neuroscience research centers in Europe. The results of the latest research have been presented in the journal Nature Biotechnology.   

Embryonic stem cells can be turned into any other type of cell in the body and have potential uses in treatments where sick cells need to be replaced.    

However, a major problem is that it is difficult to culture and develop human embryonic stem cells without simultaneously contaminating them as they are cultured with the help of proteins from animals.   

Another method is to culture the stem cells on other human cells, known as feeder cells, but these release thousands of uncontrolled proteins and, therefore, lead to unreliable research results. 

A research team at Karolinska Institutet, KI, has managed to produce human stem cells entirely without the use of other cells or substances from animals. Instead, they are cultured on a matrix of a single human protein: laminin-511, according to News-Medical.net.    

"Now, for the first time, we can produce large quantities of human embryonic stem cells in an environment that is completely chemically defined," Professor Karl Tryggvason, who led the study said at the KI Monday. "This opens up new opportunities for developing different types of cell which can then be tested for the treatment of disease."    

Together with researchers at the Harvard Stem Cell Institute, the KI researchers have also shown that they can culture in the same way what are known as "reprogrammed stem cells", which have been converted "back" from tissue cells to stem cells.    

Laminin-511 is part of our connective tissue and acts in the body as a matrix to which cells can attach. In the newly formed embryo, the protein is also needed to keep stem cells as stem cells. Once the embryo begins to develop different types of tissue, other types of laminin are needed.    
Until now, different types of laminin have not been available to researchers, because they are almost impossible to extract from tissues and difficult to produce.   

Over the last couple of decades, Karl Tryggvason's research group has cloned the genes for most human laminins, studied their biological role, described two genetic laminin diseases and, in recent years, even managed to produce several types of laminin using gene technology.   

In this latest experiment, the researchers produced the laminin-511 using recombinant techniques, News-Medical.net said.