Bone protein analysis may augment osteoporosis testing technology

Healthcare professionals looking for the signs of osteoporosis typically test bone for its density and calcium content, but new innovations in the field of proteomics may lead to an expansion of such testing to incorporate bone protein exams.

In a study published in the journal Molecular and Cellular Proteomics, researchers from the Rensselaer Polytechnic Institute in Troy, New York, announced the creation of a bone analysis technique that examines skeletal tissue at the molecular level.

The new, multi-step method is designed to sequence the different kinds of proteins found in bones, as well as to determine the structural soundness of the bones being tested. Based in proteomics, the technique combines laser capture microscopy, liquid chromatography, gel electrophoresis and mass spectrometry analysis.

Proteomics is a field of inquiry established fairly recently, the team said, noting that its novelty allowed them to be flexible and creative when looking for new ways to test for osteoporosis.

The word "proteomics" was coined in 1997 in an article published in the journal Quarterly Reviews of Biophysics. The term is intentionally reminiscent of "genomics," or the mapping of the complete human genetic structure. Proteomics is essentially the mapping of the structure of all human proteins.

Scientists at the John Jay College of Criminal Justice estimate that there are more than 100,000 different proteins in the body. Many of these contribute to bone structure, density and strength, and the new testing system may help researchers determine how.

The team noted that the technique began with laser capture microscopy, also called microdissection. Using a specially designed microscope, scientists targeted a tiny portion of bone matrix, which was then cut away using a fine laser.

Afterwards, the sample tissue was sifted using liquid chromatography and gel electrophoresis, in which electric current separates proteins based on their size and charge. Finally, mass spectroscopy revealed the types and amounts of different proteins found in bone.

The research team noted that such technology may improve the ability to test the quality of bone, especially in individuals who are gradually losing skeletal minerals.

"In osteoporosis, very little attention has been paid to bone proteins. That's why we're very excited about our new proteomics-based method to read a bone's protein signature and assess the quality of the bone. I think it opens up a new avenue for approaching and studying osteoporosis," said lead author Deepak Vashishth.