Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gut protein found to protect against infection and intestinal breakdown

08.02.2006


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.

B ile, 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.

Aline McKenzie | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Researchers target protein that protects bacteria's DNA 'recipes'
21.08.2018 | University of Rochester

nachricht Protein interaction helps Yersinia cause disease
21.08.2018 | Schwedischer Forschungsrat - The Swedish Research Council

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>