Navigation Links
Amid the murk of 'gut flora,' vitamin D receptor emerges as a key player
Date:7/7/2010

Within the human digestive tract is a teeming mass of hundreds of types of bacteria, a potpourri of microbes numbering in the trillions that help us digest food and keep bad bacteria in check.

Now scientists have found that the vitamin D receptor is a key player amid the gut bacteria what scientists refer to matter-of-factly as the "gut flora" helping to govern their activity, responding to their cues, and sometimes countering their presence. The work was published online recently in the American Journal of Pathology.

The findings deliver a new lead to scientists investigating how bacteria might play a role in the development of inflammatory bowel diseases such as Crohn's disease or ulceractive colitis. The work complements studies suggesting that Salmonella infection can increase the risk of inflammatory bowel disease.

"Vitamin D deficiency is a known factor in the pathology of inflammatory bowel disease and colon cancer," said microbiologist Jun Sun, Ph.D., of the University of Rochester Medical Center, "but there have been very few reports about how bacteria might play a role by targeting the vitamin D receptor. Our work suggests one possible mechanism, by working through the vitamin D receptor, a sensor and regulator for the majority of functions of vitamin D."

Sun specializes in the actions of bacteria in the body and how their interactions within the body contribute to disease. She has shown that bacteria often found in the human intestine affect molecular signals known to contribute to inflammatory response and cell growth.

Her work with the vitamin D receptor takes place at a time when the molecule is coming under increasing scrutiny. Scientists have associated vitamin D and the receptor with many types of cancer, as well as osteoporosis, heart disease, diabetes, inflammatory bowel disease, and infection.

Sun's team took a close look at the vitamin D receptor in mice and its interactions with bacteria in the colon. The team studied normal mice; mice in which the vitamin D receptor had been knocked out; and mice that were completely free of any germs. Scientists observed how the mice responded to infection with either a harmless strain of E. coli or a pathogenic strain of Salmonella Typhimurium.

The team found that Salmonella is able to regulate the vitamin D receptor, increasing its activity and determining where in the colon the receptor is active. In the presence of Salmonella, the receptor was more prevalent than usual deep within folded intestinal structures known as crypts.

Sun's team also discovered that the vitamin D receptor plays a key role in defending the body from assault by Salmonella and squelching inflammation. The receptor stops a molecule known as NF-Kappa B, a well-known master player in the world of inflammation, by binding to it and preventing it from activating other inflammatory molecules. While scientists have known that the receptor interacts with NF-Kappa B, details of the interaction modulated by bacteria in the colon are new.

The scientists found that Salmonella was much more virulent and aggressive in mice in which the vitamin D receptor had been turned off. These mice showed higher levels of activity of inflammatory molecules, and they lost weight more quickly and were much more likely to die in response to infection.

"We live together in a mutually beneficial state with most of the bacteria in our gut," said Sun, assistant professor in the Gastroenterology and Hepatology Division of the Department of Medicine. "They help us digest foods like fruits and vegetables, and we provide them a place to live and thrive. We co-exist peacefully most of the time.

"But we aren't able to culture most of these bacteria in the laboratory, and we don't know what most of them are doing. We need to understand our gut flora much more than we do. This is particularly important for understanding how we might manipulate the natural gut flora to stop an invader like Salmonella," added Sun, who also has appointments in the James P. Wilmot Cancer Center and the Department of Microbiology and Immunology.


'/>"/>

Contact: Tom Rickey
tom_rickey@urmc.rochester.edu
585-275-7954
University of Rochester Medical Center
Source:Eurekalert

Related biology news :

1. Dont forget the vitamin A when working with its carrier protein
2. Vitamin C supplements may reduce benefit from wide range of anti-cancer drugs
3. Vitamin D a key player in overall health of several body organs, says UC Riverside biochemist
4. Lack of vitamin D linked to Parkinsons disease
5. Vitamin K does not stem BMD decline in postmenopausal women with osteopenia
6. Optimal dose of vitamin E maximizes benefits, minimizes risk
7. Lung airway cells activate vitamin D and increase immune response
8. Could vitamin D save us from radiation?
9. Vitamin C lowers levels of inflammation biomarker considered predictor of heart disease
10. Vitamin D found to fight placental infection
11. Calcium and vitamin D may not be the only protection against bone loss
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2016)... , May 16, 2016   EyeLock LLC , ... announced the opening of an IoT Center of Excellence ... and expand the development of embedded iris biometric applications. ... level of convenience and security with unmatched biometric accuracy, ... identity aside from DNA. EyeLock,s platform uses video technology ...
(Date:4/28/2016)... SAN FRANCISCO and BANGALORE, India ... part of EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... service provider, today announced a global partnership that ... convenient way to use mobile banking and payment services. ... Mobility is a key innovation area for financial services, but ...
(Date:4/19/2016)... 20, 2016 The new GEZE ... compact web-based "all-in-one" system solution for all door components. ... or the door interface with integration authorization management system, ... systems. The minimal dimensions of the access control and ... building installations offer considerable freedom of design with regard ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report published today in ... patient who developed lymphedema after being treated for breast cancer benefitted from an injection ... for dealing with this debilitating, frequent side effect of cancer treatment. , ...
(Date:6/23/2016)... , June 23, 2016  Blueprint Bio, a ... discoveries to the medical community, has closed its Series ... Matthew Nunez . "We have received a ... the capital we need to meet our current goals," ... provide us the runway to complete validation on the ...
(Date:6/23/2016)... 23, 2016 On Wednesday, June 22, ... down 0.22%; the Dow Jones Industrial Average edged 0.27% lower ... 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage on the following ... Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals Inc. (NASDAQ: ... BIND ). Learn more about these stocks by accessing ...
(Date:6/23/2016)... ... 23, 2016 , ... Regulatory Compliance Associates® Inc. (RCA), a ... webinar on Performing Quality Investigations: Getting to Root Cause. This ... charge. , Incomplete investigations are still a major concern to the Regulatory Authorities ...
Breaking Biology Technology: