Featured Research

from universities, journals, and other organizations

Timing is everything in combination therapy for osteoporosis

Date:
November 6, 2010
Source:
Cell Press
Summary:
The adult human skeleton undergoes constant remodeling, with new bone forming at sites that have been broken down by a precise process called resorption. During remodeling, skeletal stem cells are recruited to resorption sites and directed to differentiate into bone-forming cells.

The adult human skeleton undergoes constant remodeling, with new bone forming at sites that have been broken down by a precise process called resorption. During remodeling, skeletal stem cells are recruited to resorption sites and directed to differentiate into bone-forming cells. Osteoporosis, a condition characterized by weak and fragile bones, develops when there is an imbalance in the remodeling process and more bone is lost than replaced. Now, new research published by Cell Press in the November issue of the journal Cell Stem Cell uncovers a mechanism that may guide development of better strategies for treatment osteoporosis.

Osteoporosis is often treated with drugs that inhibit bone resorption, such as alendronate, or drugs that stimulate bone formation, such as parathyroid hormone (PTH). Surprisingly, previous attempts to combine these approaches were not effective. "In clinical trials where PTH and alendronate were administered concurrently, the bone building effects of PTH were impaired," explains senior study author Dr. Xu Cao from The Johns Hopkins School of Medicine in Baltimore, MD. "This suggests that bone resorption is necessary for PTH-induced bone formation, but the underlying mechanisms are obscure. An improved understanding of the role that bone resorption plays in PTH-induced bone formation would provide a key mechanistic rationale for the development of strategies that maximize use of both PTH and antiresorptive drugs in the treatment of osteoporosis."

Dr. Cao's group had previously shown that transforming growth factor (TGF)-?1 plays a key role in bone formation after bone resorption. In the current study, the researchers identified a subset of skeletal stem cells that were recruited to bone remodeling sites in response to bone resorption. Importantly, the authors demonstrated the TGF-?1 is essential for recruitment of skeletal stem cells during PTH-stimulated bone remodeling. Further, alendronate inhibited release of TGF-?1 during bone resorption.

"Our research shows that inhibition of TGF-?1 activation by alendronate leads to insufficient recruitment of skeletal stem cells to resorptive sites for the new bone formation during PTH-stimulated bone remodeling," says Dr. Cao. "Given this mechanism, it is possible that the use of PTH before treatment by an antiresorptive drug like alendronate could be an effective therapy." Taken together, the findings help to explain why the order and timing of combination drug therapy may be critical for successful treatment of osteoporosis and may help to direct the design of future clinical trials.

The researchers include Xiangwei Wu, The Johns Hopkins University School of Medicine, Baltimore, MD, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, China; Shihezi University, Shihezi, Xinjiang, China; Lijuan Pang, The Johns Hopkins University School of Medicine, Baltimore, MD, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, China, Shihezi University, Shihezi, Xinjiang, China; Weiqi Lei, The Johns Hopkins University School of Medicine, Baltimore, MD William Lu, The University of Hong Kong, Hong Kong, China; Jun Li, The Johns Hopkins University School of Medicine, Baltimore, MD, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, Wuhan, China; Shihezi University, Shihezi, Xinjiang, China; Zhaoyang Li, The University of Hong Kong, Hong Kong, China; Frank J. Frassica, The Johns Hopkins University School of Medicine, Baltimore, MD; Xueling Chen, The Johns Hopkins University School of Medicine, Baltimore, MD; Shihezi University, Shihezi, Xinjiang, China; Mei Wan, The Johns Hopkins University School of Medicine, Baltimore, MD and Xu Cao, The Johns Hopkins University School of Medicine, Baltimore, MD.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Xiangwei Wu, Lijuan Pang, Weiqi Lei, William Lu, Jun Li, Zhaoyang Li, Frank J. Frassica, Xueling Chen, Mei Wan, Xu Cao. Inhibition of Sca-1-Positive Skeletal Stem Cell Recruitment by Alendronate Blunts the Anabolic Effects of Parathyroid Hormone on Bone Remodeling. Cell Stem Cell, 2010; 7 (5): 571-580 DOI: 10.1016/j.stem.2010.09.012

Cite This Page:

Cell Press. "Timing is everything in combination therapy for osteoporosis." ScienceDaily. ScienceDaily, 6 November 2010. <www.sciencedaily.com/releases/2010/11/101104154215.htm>.
Cell Press. (2010, November 6). Timing is everything in combination therapy for osteoporosis. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2010/11/101104154215.htm
Cell Press. "Timing is everything in combination therapy for osteoporosis." ScienceDaily. www.sciencedaily.com/releases/2010/11/101104154215.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Quintuplets Head Home

Texas Quintuplets Head Home

Reuters - US Online Video (Aug. 1, 2014) After four months in the hospital, the first quintuplets to be born at Baylor University Medical Center head home. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Ebola Patient Coming to U.S. for Treatment

Ebola Patient Coming to U.S. for Treatment

Reuters - US Online Video (Aug. 1, 2014) A U.S. aid worker infected with Ebola while working in West Africa will be treated in a high security ward at Emory University in Atlanta. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Ebola Vaccine Might Be Coming, But Where's It Been?

Ebola Vaccine Might Be Coming, But Where's It Been?

Newsy (Aug. 1, 2014) Health officials are working to fast-track a vaccine — the West-African Ebola outbreak has killed more than 700. But why didn't we already have one? Video provided by Newsy
Powered by NewsLook.com
Study Links Certain Birth Control Pills To Breast Cancer

Study Links Certain Birth Control Pills To Breast Cancer

Newsy (Aug. 1, 2014) Previous studies have made the link between birth control and breast cancer, but the latest makes the link to high-estrogen oral contraceptives. 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:
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