Featured Research

from universities, journals, and other organizations

Gut Protein Found To Protect Against Infection And Intestinal Breakdown

Date:
February 8, 2006
Source:
UT Southwestern Medical Center
Summary:
A protein that binds to bile in the small intestine may hold the key to preventing infection and intestinal breakdown in people with conditions such as obstructive jaundice or irritable bowel syndrome, researchers at UT Southwestern Medical Center have discovered.

UT Southwestern researchers led by Dr. Steven Kliewer (right), professor of molecular biology, and including Dr. Takeshi Inagaki, postdoctoral research fellow in pharmacology, have identified one of the mechanisms for how the body keeps the number of bacteria low in the small intestine, and how it prevents them from getting into other organs.
Credit: Image courtesy of UT Southwestern Medical Center

A protein that binds to bile in the small intestine may hold the key to preventing infection and intestinal breakdown in people with conditions such as obstructive jaundice or irritable bowel syndrome, researchers at UT Southwestern Medical Center have discovered.

"What we've identified is one of the mechanisms for how the body keeps the number of bacteria low in the small intestine, and how it prevents them from getting into other organs," said Dr. Steven Kliewer, professor of molecular biology and the study's senior author. The study is available this week online and in an upcoming issue of the Proceedings of the National Academy of Sciences.

Bile, which is generated by the liver and flows into the small intestine via a duct, contains harsh acids that help the body absorb nutrients, kill certain bacteria and help keep intact the lining of the intestine, a major barrier against the infiltration of infectious microorganisms. That's no small task; if the innermost lining of the small intestine alone were unfolded, it would be the size of a tennis court.

When there's no bile in the intestine, as happens in people with obstructive jaundice or in those who rely on feeding tubes for nourishment, the lining breaks down and bacteria pass through it into the body, sometimes causing the massive blood infection known as sepsis. Simply giving bile acids orally as a substitute isn't a good solution because they can cause liver damage, Dr. Kliewer said.

The researchers focused on a molecule — FXR — in the wall of the lining, which binds to bile acids. When FXR was activated by a synthetic binding chemical called GW4064, it was found to activate several genes that are known to protect the intestinal lining or attack bacteria.

The research team also found that FXR molecules heavily lined the inside folds of the intestine in adult mice.
"It's perfectly positioned," Dr. Kliewer said. "It's expressed in just the right place to protect us from the environment."

When the bile ducts of mice were tied off, preventing bile from reaching the intestine, adding GW4064 prevented damage to the intestines, showing that it can replace bile in protecting the small intestine.

Genetically engineered mice that lacked FXR showed overall damage to the intestines, "strong evidence that this protein is crucial," Dr. Kliewer said. Drugs that bind to FXR, he said, could eventually become useful in treating various conditions of the small intestine.

Other UT Southwestern researchers involved in the study were Drs. Takeshi Inagaki and Guixiang Zhao, postdoctoral research fellows in molecular biology; Dr. Antonio Moschetta, postdoctoral research fellow in pharmacology and a research associate in the Howard Hughes Medical Institute; Youn-Kyoung Lee, student research assistant in molecular biology; Li Peng, senior research associate in molecular biology; John Shelton, senior research scientist in internal medicine; Dr. James Richardson, professor of pathology; Dr. Joyce Repa, assistant professor of physiology; and Dr. David Mangelsdorf, professor of pharmacology and biochemistry and an HHMI investigator. Drs. Ruth Yu and Michael Downes of the Salk Institute for Biological Studies in La Jolla, Calif., also participated in the study.

The work was supported by the National Institutes of Health, the HHMI and The Welch Foundation.


Story Source:

The above story is based on materials provided by UT Southwestern Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

UT Southwestern Medical Center. "Gut Protein Found To Protect Against Infection And Intestinal Breakdown." ScienceDaily. ScienceDaily, 8 February 2006. <www.sciencedaily.com/releases/2006/02/060207232927.htm>.
UT Southwestern Medical Center. (2006, February 8). Gut Protein Found To Protect Against Infection And Intestinal Breakdown. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2006/02/060207232927.htm
UT Southwestern Medical Center. "Gut Protein Found To Protect Against Infection And Intestinal Breakdown." ScienceDaily. www.sciencedaily.com/releases/2006/02/060207232927.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
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:
from the past week

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