About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Key Details of How Rheumatoid Arthritis Causes Bone Loss Revealed

by Hannah Punitha on August 22, 2008 at 8:43 PM
Font : A-A+

 Key Details of How Rheumatoid Arthritis Causes Bone Loss Revealed

Researchers from University of Rochester Medical Centre have identified key details of how rheumatoid arthritis (RA) destroys bone.

In rheumatoid arthritis, the body's disease-fighting immune cells mistakenly identify parts of a person's body as foreign invaders, similar to bacteria, and produce chemicals to destroy them.

Advertisement

The immune chemicals called tumour necrosis factor alpha (TNF alpha) are known to play a central in the autoimmune disease. It increases the production of immune cells and chemicals as part of the body's response to disease.

When overproduced in RA patients, TNF alpha signals for the destruction of cartilage and bone.

TNF alpha also influences bone mass. Human bone is continually regenerated to maintain strength. Under the control of signaling molecules, which include TNF alpha, two cell types, balanced against each other, make bone recycling possible.
Advertisement

Osteoclasts break down aging bone to make way for new bone, while osteoblasts build new bone at the sites where osteoclasts have removed it.

The research team found that TNF alpha decreases the number of bone-building osteoblasts, through an enzyme called Smad Ubiquitin Regulatory Factor 1 (Smurf1), which in turn shuts down two proteins that would otherwise drive bone-building.

Lianping Xing, Ph.D., assistant professor of Pathology and Laboratory Medicine at the University of Rochester Medical Centre and his colleagues generated two lines of mice - one with high TNF alpha levels and with Smurf1 present, and a second group with high TNF alpha production but no Smurf1.

Bone volume and strength of both groups of mice were then examined using a combination of imaging technologies and were compared.

The results showed that increased TNF alpha levels dramatically decreased the levels of two key factors, Smad1 and Runx2.

Both Smad1 and Runx2 signalled to increase the number of bone-building osteoblasts, but only if Smurf1 was present to pass on the signal from TNF alpha.

"The significance of our study is that it identifies SMURF1 as the signalling partner through which TNF does damage in RA-related bone loss," said Xing.

"That has enabled researchers to begin designing small molecule drugs to shut down the action of Smurf 1 and its relatives," Xing added.

The study is published in the Aug. 22 edition of the Journal of Biological Chemistry.

Source: ANI
SPH
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
First Dose of COVID-19 Vaccines May Improve Mental Health
Printed Temperature Sensors help with Continuous Temperature Monitoring
Health Benefits of Giloy
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Osteoarthritis Rheumatoid Arthritis Infantile Cortical Hyperostosis Oligoarthritis Spondylolisthesis Chemotherapy Chemotherapy Drugs Knee Replacement Reactive Arthritis Hypermobility Syndrome 

Recommended Reading
Osteoarthritis
Osteoarthritis is one of the commonest joint disorder and occurs as we age due to wear and tear of ....
Oligoarthritis
Most parents when told that their child has arthritis find it hard to believe it, as arthritis is .....
Chemotherapy
‘Chemo’ means medicine or ‘drug’; ‘therapy’ means ‘treatment’. Chemotherapy refers to the use of cy...
Chemotherapy Drugs
Chemotherapy drugs perform like ‘magic bullets’ to destroy cancer cells in the body....
Hypermobility Syndrome
Hypermobility Syndrome is a condition in which a person can move his joints far beyond the normal .....
Infantile Cortical Hyperostosis
Infantile Cortical Hyperostosis is a disease of unknown cause, where bizarre thickening of the corti...
Knee Replacement
Make sprinting a possibility! Relieve chronic arthritic pain by having a knee replacement done at ...
Reactive Arthritis
Reactive arthritis is an autoimmune condition. Ankylosing spondylitis, psoriatic arthritis are disor...
Rheumatoid Arthritis
Rheumatoid arthritis is a chronic inflammatory disease that causes pain, swelling, stiffness and los...
Spondylolisthesis
Spondylolisthesis is a condition of the lower spine in which one of the bones of the vertebral colum...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use