HOME >> MEDICINE >> NEWS
Scientists identify key mechanism in estrogen's role in preventing bone loss

n deficiency, they removed the ovaries from mice, then studied the effects of estrogen on immune cells and on bone marrow in culture. They measured the level of TGFb in bone marrow macrophages (BMM) and discovered that the level of TGFb in the BMM of mice lacking ovaries was about half that of mice with ovaries. When they treated the mice with estrogen, levels of TGFb in the bone marrow increased about three-fold in mice with ovaries and about eight-fold in mice without ovaries.

In order to test the effects of TGFb on bone-marrow density, the scientists used a transgenic mouse model in which TBFb signaling in T cells is blocked. Although these mice had the same level of bone density as control mice at birth, they gradually lost bone density over time, suggesting that when T cells are insensitive to TGFb signaling, they stimulate the loss of bone.

"Our research shows that mice with T-cell specific blockade of TGFb signaling are completely insensitive to the bone-sparing effects of estrogen," says Dr. Pacifici. "This results from a failure of estrogen to repress the production of IFN-g, which in turn leads to increased T cell activation and TNF production. We also found in mice that a lack of estrogen production blunts the levels of TGFb in the bone marrow and that overexpression of TGFb in vivo prevents bone loss caused by removal of the ovaries. This critical mechanism in the estrogen-bone loss pathway, should it be confirmed in humans, could lead us to inhibition of T-cell activation or simulation of TGFB signaling as new therapeutic approaches for preventing bone loss."

Other authors included Wei-Ping Qian, Kimberly Dark, Gianluca Toraldo, and M. Neale Weitzmann from Emory School of Medicine; Angela S.P. Lin and Robert E. Guldberg from the Georgia Institute of Technology; and Richard A. Flavell from Yale University School of Medicine. The research was supported by grants from the National Institutes of Health.


'"/>

Contact: Holly Korschun
hkorsch@emory.edu
404-727-3990
Emory University Health Sciences Center
28-Oct-2004


Page: 1 2

Related medicine news :

1. Scientists replicate hepatitis C virus in laboratory
2. Scientists identify brain regions that decide where we look
3. Scientists uncover new mechanism for the amygdala in fear recognition
4. Scientists identify protein critical to melanoma growth
5. Scientists discover recipe for life: eating the Polymeal cuts heart disease by 76%
6. Scientists study fish oil diet in bid to cut heart attack risks
7. Scientists discover enzyme crucial to the transportation of proteins within cells
8. Scientists turn on the gender lens on cardiovascular disease research
9. Scientists stalk PPAR-gamma, find novel cancer connection
10. Scientists align billion-year-old protein with embryonic heart defects
11. Scientists pinpoint flaw, offer new promise for stroke treatment

Post Your Comments:
(Date:11/24/2014)... "My friend was killed when a vehicle ... street in his motorized wheelchair," said an inventor from ... up with this idea so that people in wheelchairs ... the Safety Lites to make a wheelchair highly visible, ... ensures that motorists can see the wheelchair. This helps ...
(Date:11/23/2014)... iFitDress.com, a well-known wedding dress manufacturer, has unveiled ... They are now offered at deeply discounted prices, up ... now to Dec. 15. The main purpose of the promotion ... high quality items are ideal options for ladies who are ... money. All its new mint cocktail dresses are very beautiful; ...
(Date:11/23/2014)... The report, “Market Snapshot: Aesthetic Lasers ... Asia-Pacific” provides quantitative analysis of the three aesthetic ... body contouring devices, non-invasive body contouring devices and ... data by revenue and volume over the 2006 ... South Korea, Australia and India. It uses data ...
(Date:11/23/2014)... Pro Ace Care, a renowned Vancouver hot water tank company, ... 8 year warranty on its selected hot water tanks. As ... to the impending winter season, it was important for Pro ... that the company provides. As a result, Pro Ace will ... Bradford hot water tanks. , “Every installer who works ...
(Date:11/23/2014)... 21, 2014 (HealthDay News) -- Close friends have more ... group does, a new study says. "We,ve ... have an influence on individual alcohol use, but there ... peer group and the friend group,s influence on those ... School of Public Health, said in a university news ...
Breaking Medicine News(10 mins):Health News:Trendy Long Black Evening Gowns Now Provided By iFitDress.com 2Health News:Aesthetic Lasers and Energy Devices Market in APAC (China, Japan, South Korea, Australia and India) to 2020 2Health News:Aesthetic Lasers and Energy Devices Market in APAC (China, Japan, South Korea, Australia and India) to 2020 3Health News:Aesthetic Lasers and Energy Devices Market in APAC (China, Japan, South Korea, Australia and India) to 2020 4Health News:Pro Ace Care Now Gives 8 Year Guarantee on Selected Vancouver Hot Water Tanks 2Health News:Close Friends May Be Key to Teens' Drinking 2
(Date:11/24/2014)...  AiCure, an artificial intelligence company providing advanced ... ingestion, has announced the start of a major ... receiving medication as maintenance therapy for opioid addiction. ... have quadrupled in the last 15 years. Opioids ... cocaine and benzodiazepines combined. Overall, the economic cost ...
(Date:11/24/2014)... 24, 2014  Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL ... from the board of directors and from his positions as ... most recently serving as the company,s president and chief operating ... join the board of directors.  Gary Lyons , a ... chairman. Mr. Gower is expected to remain an employee until ...
(Date:11/24/2014)... Pa. , Nov. 24, 2014  Inovio Pharmaceuticals, Inc. ... J. Joseph Kim , President and CEO of Inovio Pharmaceuticals, ... management team to ring the Nasdaq Opening Bell tomorrow, Tuesday ... Inovio,s September 15 th listing on the Nasdaq Global ... ceremony, Dr. Kim said, "We are honored to ring the ...
Breaking Medicine Technology:Can artificial intelligence solve the $55 billion problem of opioid abuse? 2Rigel Announces Executive Management Changes 2Rigel Announces Executive Management Changes 3Inovio Pharmaceuticals to Ring Opening Bell Nov 25th on the Nasdaq Stock Market 2Inovio Pharmaceuticals to Ring Opening Bell Nov 25th on the Nasdaq Stock Market 3
Cached News: