Abstract
Introduction
Elastic fibres are constructed of a central core of elastin surrounded by microfibrils that are composed mainly of fibrillin-1 and fibrillin-2. Patients with mutations in the gene encoding fibrillin-1 or fibrillin-2 develop Marfan syndrome or Beals syndrome (congenital contractural arachnodactyly), respectively. Scoliosis is one of the clinical manifestations in these patients, but how a defect in the elastic proteins could lead to a spinal deformity is not clear. On the one hand, the mutations could induce scoliosis via mechanical means as they could lead to alterations in the biomechanics of the elastic fibre system. On the other hand, elastic fibres also bind growth factors such as transforming growth factor β (TGFβ) and bone morphogenic proteins (BMPs), and the mutations could hence change patterns of spinal growth.
Methods
We have investigated the localisation of elastic proteins in different spinal tissues at different stages of curve development in mouse models and in human tissue obtained during scoliosis surgery.
Results
Elastic proteins were observed not only in the spinal connective tissues such as ligaments and intervertebral discs, but also in muscle and the bone matrix. The distribution of the different elastic proteins was tissue specific. Additionally, elastic proteins were also detected in the matrix of the vertebral-body growth plates (figure), which has not been reported previously.
Conclusions
These observations suggest that elastic proteins could have several functions in the spinal column. Their presence and organisation in the growth plate suggests that they could play an important part in orchestration of spinal growth; a fibrillin mutation-induced malfunction in this regard could be a factor in the development of scoliosis.
