Navigation Links
Gains made towards treatment of rare bone disease

This press release is available in French.

Diagnosed in toddlers, X-linked hypophosphatemia (XLH) is the most common form of heritable rickets, in which soft bones bend and deform, and tooth abscesses develop because infections penetrate soft teeth that are not properly calcified. Researchers at McGill University and the Federal University of Sao Paulo have identified that osteopontin, a major bone and tooth substrate protein, plays a role in XLH. Their discovery may pave the way to effectively treating this rare disease.

The findings were made by the laboratories of Marc McKee, a professor in the Faculty of Dentistry and the Department of Anatomy and Cell Biology at McGill University, and of Nilana M.T. Barros, a professor at the Federal University of Sao Paulo. The team built upon previous research that had shown that mutations in the single gene PHEX are responsible for causing XLH. The results of this latest research by Drs. McKee and Barros will be published in the March issue of the Journal of Bone and Mineral Research.

"XLH is caused in part by renal phosphate wasting, which is the urinary loss from the body of phosphate, an important building block of bones and teeth, along with calcium." says Prof. McKee. "In pursuing other factors that might contribute to XLH, we used a variety of research methods to show that PHEX enzymatic activity leads to an essentially complete degradation of osteopontin in bones."

This loss of osteopontin, a known potent inhibitor of mineralization (or calcification) in the skeleton and dentition, normally allows bones and teeth to mineralize and thus harden to meet the biomechanical demands placed on them. In XLH patients lacking functional PHEX enzyme, osteopontin and some of its smaller potent inhibitory peptides are retained and accumulate within the bone. This prevents their hardening and leads to soft deformed bones such as bowed legs (or knock-knees) seen in toddlers.

While not life-threatening, this decreased mineralization of the skeleton (osteomalacia), along with the soft teeth, soon leads to a waddling gait, short stature, bone and muscle pain, weakness and spontaneous tooth abscesses.

The fact that these symptoms are only partially improved by the standard treatment with phosphate which improves circulating phosphate levels prompted the researchers to look for local factors within the bone that might be blocking mineralization in these patients.

"With this new identification of osteopontin as a substrate protein for PHEX," says Professor Barros, "we can begin to develop an enzyme-replacement therapy to treat XLH patients who have nonfunctional PHEX, much as has been done using a different enzyme to treat another rare bone disease called hypophosphatasia."


Contact: Cynthia Lee
McGill University

Related medicine news :

1. Scientists identify major source of cells defense against oxidative stress
2. Omega-3 Supplements No Help Against Repeat Heart Trouble: Review
3. Kinase test may yield big gains for drug-resistant cancers
4. Will women use microbicides to protect themselves against HIV?
5. Vitamin E in diet protects against many cancers
6. Lower-Dose Radioiodine Effective Against Thyroid Cancer
7. Study identifies possible protective blood factors against Type 2 diabetes
8. New study of NIH funding allocations suggests potential efficiency gains
9. Stem Cell Study Shows Promising Results Against Heart Failure
10. Blood pressure drugs dont protect against colorectal cancer
11. CNIO scientists successfully test the first gene therapy against aging-associated decline
Post Your Comments:
(Date:11/30/2015)... , ... November 30, 2015 , ... ... continuing education course in Dallas, TX, on January 29 and 30, 2016. The ... improve the functions of their practices, to learn how to better succeed in ...
(Date:11/30/2015)... (PRWEB) , ... November 30, 2015 , ... ... a key disease-causing component of bacteria could be effective in fighting methicillin-resistant Staphylococcus ... Georgia State University. , Their study showed that small molecule analogs that target ...
(Date:11/30/2015)... ... November 30, 2015 , ... Dr. Seth D. Margulies ... locations, patients can visit Dr. Margulies to experience the best available orthodontic experience in ... title of "NJ Top Dentist"! , Orthodontics is the branch of dentistry that specializes ...
(Date:11/30/2015)... ... 2015 , ... ”Dying Words: The AIDS Reporting of Jeff Schmalz and How ... coincide with World AIDS Day. The multi-media project will be in audio documentary form ... he was dying of the disease. , A collaborative effort led by author, professor ...
(Date:11/30/2015)... (PRWEB) , ... November 30, 2015 , ... ... Reports magazine, quoted Michael Hansen, Ph.D., a senior scientist at Consumer Reports as ... more so for a child’s exposure limits. , The original Nov 2015 CR ...
Breaking Medicine News(10 mins):
(Date:11/30/2015)... KONG, Nov. 30, 2015 (HK$,000)For the Six Months Ended 30 September 2015 ... Income , 421,979 , 384,242 , ... , 34,719 , (18.3) Medical Insurance ... , 16.1 Medical Devices and Accessories Sales , ... Chinese Herbal Medicines Sales , 2,822 , ...
(Date:11/30/2015)... Calif. , Nov. 30, 2015 /PRNewswire/ ... the norm in U.S. medical imaging is ... increasingly popular accountable care payer-provider contracts are ... and, in their wake, alter provider-vendor relationships. ... payments will push forward new purchasing frameworks ...
(Date:11/30/2015)... Nov. 30, 2015 Oramed Pharmaceuticals Inc. (NASDAQ: ... the development of oral drug delivery systems, announced today ... at up to $50,000,000 with Hefei Tianhui Incubator of Technologies Co., Ltd. ... capsule, ORMD-0801, in China , ... . The agreements were signed at the Israel ...
Breaking Medicine Technology: