Featured Research

from universities, journals, and other organizations

Stem Cells Can Convert To Liver Tissue, Help Restore Damaged Organ

Date:
June 2, 2004
Source:
Johns Hopkins Medical Institutions
Summary:
Bone marrow stem cells, when exposed to damaged liver tissue, can quickly convert into healthy liver cells and help repair the damaged organ, according to new research from the Johns Hopkins Kimmel Cancer Center.

Bone marrow stem cells, when exposed to damaged liver tissue, can quickly convert into healthy liver cells and help repair the damaged organ, according to new research from the Johns Hopkins Kimmel Cancer Center.

In mouse-tissue cultures, scientists found that stem cells, in the presence of cells from damaged liver tissue, developed into liver cells in as little as seven hours. They also observed that stem cells transplanted into mice with liver injuries helped restore liver function within two to seven days. The work was published in the June 1 issue of the journal Nature Cell Biology.

Bone marrow stem cells, also known as hematopoietic stem cells, have the ability to differentiate and develop into all other blood and marrow cells. There has been debate among the scientific community over whether these cells also can differentiate into other tissue types such as the liver, says Saul J. Sharkis, Ph.D., senior author of the study and a professor of oncology at the Johns Hopkins Kimmel Cancer Center. Some studies suggest that the bone marrow cells fuse with other types of cells, taking on those cells' properties. But in this study, the researchers found, through highly thorough analysis with a microscope and other tests, that the cells did not fuse, suggesting that "microenvironmental" cues from existing liver cells caused them to convert.

"The hematopoietic stem cells were capable of taking on many characteristics of liver cell types, including specific gene and/or protein expression as well as typical function," Sharkis says. "These events occurred rapidly after injury exposure and restored liver abnormalities, indicating that the cells converted."

This type of stem cell technique could eventually be used to treat chronic diseases such as diabetes, cirrhosis of the liver, heart disease and cancer, he says. He cautions that many more studies must be completed before the stem cell therapy can be tested in humans.

For the study, Sharkis and colleagues cultured bone marrow stem cells together with either normal or damaged liver tissue in tissue culture dishes. Liver tissue was taken from mice that had been exposed to liver-damaging drugs. The two cell types were separated by a thin, permeable wall. Researchers performed several tests looking for expression of liver proteins.

In as little as seven or eight hours after culture with the injured liver tissue, some of the stem cells expressed the typical proteins present in liver cells cytokeratin 18 or albumin. Two days after culture, nearly 3 percent of all stem cells expressed these proteins. The researchers also observed the expression of many other proteins and products normally manufactured by liver cells in their earliest stages -- all detected within eight to 48 hours of culture.

The team then used a sensitive microscope test to examine the sex chromosomes of the cells, as the stem cells were taken from male mice and the liver tissue was taken from female mice. They identified some stem cells of male donor origin with four sex chromosomes typical of liver cells but not stem cells, indicating that the stem cells themselves physically had started to change and did not fuse with the liver cells.

Finally, the team transplanted the stem cells into injured livers in female mice and studied the amount of conversion at two and seven days following the transplant. More converted cells were observed at seven days versus two days, suggesting that the cells remained viable and continued dividing or converting. The liver functions of mice receiving the stem cells recovered as early as two days after transplant.

Sharkis' continuing studies will try to identify the environmental cues responsible for cells' conversion, and examine the ability of stem cells to repair other organs.

The study was funded by the National Heart, Lung and Blood Institute, the Ludwig Foundation and Hopkins' Institute for Cellular Engineering. Co-authors were Yoon-Young Jang M.D., Ph.D.; Michael I. Collector; Stephen B. Baylin, M.D.; and Anna Mae Diehl, M.D.

###

Jang, Yoon-Young et al, "Hematopoietic Stem Cells Convert Into Liver Cells Within Days Without Fusion," Nature Cell Biology, June 1, 2004.

Links:

Johns Hopkins Kimmel Cancer Center http://www.hopkinskimmelcancercenter.org/

Nature Cell Biology http://www.nature.com/ncb/


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "Stem Cells Can Convert To Liver Tissue, Help Restore Damaged Organ." ScienceDaily. ScienceDaily, 2 June 2004. <www.sciencedaily.com/releases/2004/06/040602060318.htm>.
Johns Hopkins Medical Institutions. (2004, June 2). Stem Cells Can Convert To Liver Tissue, Help Restore Damaged Organ. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2004/06/040602060318.htm
Johns Hopkins Medical Institutions. "Stem Cells Can Convert To Liver Tissue, Help Restore Damaged Organ." ScienceDaily. www.sciencedaily.com/releases/2004/06/040602060318.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins