Japanese Team Creates Functioning Liver from Stem Cells

In what has to be considered one of the most remarkable medical developments of the past ten years, Japanese researchers announced on Friday that they were able to generate a functional human liver from stem cells.  Each cell of the human body, whether of hair or heart muscle, has the genetic capability to develop into any other type of cell.  For years scientists have pondered how to transform stem cells – the rudimentary building blocks of human embryos – into fully functioning organs.  In this case, the scientists were able to use stem cells from adults – called pluripotent stem (iPS) cells – instead of the more controversial cells derived from human embryos.

A team led by professor Hideki Taniguchi at Yokohama City University developed human iPS cells into “precursor cells”, which they then transplanted into a mouse’s head to take advantage of increased blood flow.  Although the liver that the researchers created was very small (less than one quarter of an inch long), it was capable of performing intricate liver functions such as metabolizing toxins and creating essential human proteins. 

According to the World Health Organization, there is a global shortage of organ donors – particularly for the liver — with the average wait in the United States one to three years.  According to the Yomiuri Shimbun, Japan’s leading newspaper, Taniguchi’s research could be “an important bridge between basic research and clinical application, but faces various challenges before it can be put into medical practice.”  For those on the waiting list for a life saving liver transplant, the work cannot proceed fast enough.

Photo by BWJones.