Navigation Links
Proteins causing daytime sleepiness tied to bone formation, target for osteoporosis
Date:6/12/2014

DALLAS June 12, 2014 Orexin proteins, which are blamed for spontaneous daytime sleepiness, also play a crucial role in bone formation, according to findings by UT Southwestern Medical Center researchers. The findings could potentially give rise to new treatments for osteoporosis, the researchers say.

Orexins are a type of protein used by nerve cells to communicate with each other. Since their discovery at UT Southwestern more than 15 years ago, they have been found to regulate a number of behaviors, including arousal, appetite, reward, energy expenditure, and wakefulness. Orexin deficiency, for example, causes narcolepsy spontaneous daytime sleepiness. Thus, orexin antagonists are promising treatments for insomnia, some of which have been tested in Phase III clinical trials.

UT Southwestern researchers, working with colleagues in Japan, now have found that mice lacking orexins also have very thin and fragile bones that break easily because they have fewer cells called osteoblasts, which are responsible for building bones.

"Osteoporosis is highly prevalent, especially among post-menopausal women. We are hoping that we might be able to take advantage of the already available orexin-targeting small molecules to potentially treat osteoporosis," said Dr. Yihong Wan, Assistant Professor of Pharmacology, the Virginia Murchison Linthicum Scholar in Medical Research, and senior author for the study, published in the journal Cell Metabolism.

Osteoporosis, the most common type of bone disease in which bones become fragile and susceptible to fracture, affects more than 10 million Americans. The disease, which disproportionately affects seniors and women, leads to more than 1.5 million fractures and some 40,000 deaths annually. In addition, the negative effects impact productivity, mental health, and quality of life. One in five people with hip fractures, for example, end up in nursing homes.

Orexins seem to play a dual role in the process: they both promote and block bone formation. On the bones themselves, orexins interact with another protein, orexin receptor 1 (OX1R), which decreases the levels of the hunger hormone ghrelin. This slows down the production of new osteoblasts and, therefore, blocks bone formation locally. At the same time, orexins interact with orexin receptor 2 (OX2R) in the brain. In this case, the interaction reduces the circulating levels of leptin, a hormone known to decrease bone mass, and thereby promotes bone formation. Therefore, osteoporosis prevention and treatment may be achieved by either inhibiting OX1R or activating OX2R.

"We were very intrigued by this yin-yang-style dual regulation," said Dr. Wan, a member of the Cecil H. and Ida Green Center for Reproductive Biology Sciences and UT Southwestern's Harold C. Simmons Comprehensive Cancer Center. "It is remarkable that orexins manage to regulate bone formation by using two different receptors located in two different tissues."

The central nervous system regulation through OX2R, and therefore promotion of bone formation, was actually dominant over regulation through OX1R. So when the group examined mice lacking both OX1R and OX2R, they had very fragile bones with decreased bone formation. Similarly, when they assessed mice that expressed high levels of orexins, those mice had increased numbers of osteoblasts and enhanced bone formation.


'/>"/>

Contact: Russell Rian
russell.rian@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
Source:Eurekalert  

Related medicine news :

1. Compounds in saliva and common body proteins may fend off DNA-damaging chemicals
2. Penn study shows how misfolded proteins are selected for disposal
3. RaDAR guides proteins into the nucleus
4. TSRI scientists catch misguided DNA-repair proteins in the act
5. New technology using florescent proteins tracks cancer cells circulating in the blood
6. How bacteria exploit proteins to trigger potentially lethal infections
7. Coral reefs provide potent new anti-HIV proteins
8. Dual role: Key cell division proteins also power up mitochondria
9. First observation of a human HAT, key proteins in numerous pathologies
10. NIH scientists find mechanism that helps HIV evade antibodies, stabilize key proteins
11. 2 proteins compete for 1 port on a growth factor; 1 promotes metastasis, the other blocks it
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Proteins causing daytime sleepiness tied to bone formation, target for osteoporosis
(Date:10/12/2017)... ... October 12, 2017 , ... ... for healthcare compliance program management, will showcase a range of technology and learning ... Assisted Living (NCAL) Convention and Expo to be held October 14–18, 2017 at ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... products to meet the demand of today’s consumer and regulatory authorities worldwide. From ... probiotic experts and tested to meet the highest standard. , These products ...
(Date:10/12/2017)... ... 12, 2017 , ... Asante, a nationally recognized health system ... their existing home health joint venture through an agreement, effective October 1, 2017, ... venture home health company with Asante, delivering clinically integrated care, for the past ...
(Date:10/12/2017)... ... October 12, 2017 , ... HMP , a leader in healthcare events ... Magazine Eddie Digital Award for ‘Best B-to-B Healthcare Website.’ Winners were announced during the ... The annual award competition recognizes editorial and design excellence across a range of sectors. ...
(Date:10/12/2017)... ... October 12, 2017 , ... Women-owned and Grand Rapids-based workplace ... Brightest in Wellness® by Best and Brightest. OnSite Wellness will be honored at ... from 7:30 a.m. to 2 p.m. at the Henry Autograph Collection Hotel, located ...
Breaking Medicine News(10 mins):
(Date:9/19/2017)... 2017 HistoSonics, Inc., a venture-backed medical device company developing a non-invasive, robotically assisted, ... three leadership team developments today:   ... ... Tom Tefft ... Veteran medical device executive Josh Stopek , PhD, who has ...
(Date:9/18/2017)... , Sept. 18, 2017 ... fields of bioinformatics and immune engineering, today ... protective avian influenza A (H7N9) vaccine. ... related to seasonal influenza and presents a ... on prior exposure to be effective. Using ...
(Date:9/12/2017)... 2017  Consumer reviews on the independent review site Consumer ... one company for hearing aids, ranking it higher than Miracle ... ... Consumers For Hearing Aids ... an online store that provides high performance, state-of-the-art, German-engineered hearing aids ...
Breaking Medicine Technology: