Bulletin

Issue: May 2004

Cover

Bones on the mend

Research into fractures and bone disease reveals there may be a better way to heal.

Bio-scientists at La Trobe University have made advances that may lead to better ways of repairing fractured bones and treating bone diseases such as osteoporosis.

The University’s Skeletal Biosciences Group in the Department of Human Physiology and Anatomy is following two parallel lines of research into the action of the nervous system on fractures, skeletal disease and skeletal function.

Team leader, Dr Brian Grills, a senior lecturer in Pathophysiology, said that a long-term possible outcome could be a drug that would stimulate smooth muscle contraction, resulting in improved fracture healing and bone disease treatment.

The first of the two lines of research, into the properties of a neuropeptide called Galanin, began three years ago. Researchers in a number of institutes worldwide, investigating the properties of Galanin since its discovery two decades ago, have found that Galanin plays a role in normal growth and development of the nervous system and that it is critically important for recovery of nerve function after nerve injury.

La Trobe’s Skeletal Biosciences Group has advanced this line of research with the discovery that Galanin is produced in increased quantities in bone fractures.

‘Galanin is a natural suppressor of pain and is involved in other physiologic functions. As far as I am aware, our team is the first to look at the effects of Galanin on the skeleton,’ Dr Grills said.

‘We have found that Galanin is associated with skeletal cell regulation, particularly cell division and that it is also able to increase bone formation. This last property implies that Galanin promotes fracture repair.’

Dr Grills with his colleague, Dr John Schuijers, their PhD students, Mr Aaron McDonald and Ms May Yao, and in collaboration with researchers from the University of Melbourne’s Howard Florey Institute, Drs Pei-Juan Shen and Andrew Gundlach, have recently published a report on their progress on Galanin research in the international skeletal journal, Bone.

The second line of research is the identification of two previously unknown aspects of bone fracture repair – the presence of smooth muscle-like cells in tissue that links fractured ends together (callus) and the process of fracture site contraction.

Working with La Trobe University muscle physiologist, Dr Philip Dooley and Honours student Melissa Howgate, Dr Grills discovered that tissue formed in the first few weeks after the fracture that links the fractured ends of bone together is primarily composed of smooth muscle-like tissue.

‘This tissue has the amazing ability to contract and relax, just like ordinary muscle. Contraction of new healing tissue is an essential event in early soft tissue repair, as contraction aids healing by bringing together the edges of the wound, thus reducing the amount of tissue needed for repair and restoring internal tissue tension to the wound.’

These smooth muscle-like cells, contained the contractile protein called ‘alpha smooth muscle actin’.

‘We showed that callus has the ability to contract and relax in physiologic solutions. These findings are significant in that contraction of fracture callus, like soft tissue wounds, should aid repair and that fracture repair may be affected by agents that influence smooth muscle contraction or relaxation.

‘In theory it may be possible to develop a drug that stimulates this smooth muscle contraction and thereby hastens fracture repair,’ Dr Grills said.

In March Dr Grills was an invited speaker on this research at the International Society for Fracture Repair Meeting, attended by eminent scientists, endocrinologists and orthopaedic surgeons from many countries at Clare, South Australia.

A paper on the research is due for publication this year in the world’s leading orthopaedic research journal, The Journal of Orthopaedic Research.

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