eCM (Eur Cell Mater / e Cells & Materials) Not-for-profit Open Access
Created by Scientists, for Scientists
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

2011   Volume No 22 – pages 226-241

Title: Collagen fibrillogenesis in the development of the annulus fibrosus of the intervertebral disc

Author: AJ Hayes, MD Isaacs, C Hughes, B Caterson, JR Ralphs

Address: Confocal Microscopy Unit, School of Biosciences, Cardiff University, Cardiff, CF10 3AX, Wales, UK


E-mail: Hayesaj at cf.ac.uk

Key Words: Intervertebral Disc – Development, ECM – Collagens, ECM – Proteoglycans, Imaging – EM, Imaging – LM.

Publication date: October 11th 2011

Abstract: The annulus fibrosus of the intervertebral disc is a complex, radial-ply connective tissue consisting of concentric lamellae of oriented collagen. Whilst much is known of the structure of the mature annulus, less is known of how its complex collagenous architecture becomes established; an understanding of which could inform future repair/regenerative strategies. Here, using a rat disc developmental series, we describe events in the establishment of the collagenous framework of the annulus at light and electron microscopic levels and examine the involvement of class I and II small leucine rich proteoglycans (SLRPs) in the matrix assembly process. We show that a period of sustained, ordered matrix deposition follows the initial cellular differentiation/orientation phase within the foetal disc. Fibrillar matrix is deposited from recesses within the plasma membrane into compartments of interstitial space within the outer annulus – the orientation of the secreted collagen reflecting the initial cellular orientation of the laminae. Medially, we demonstrate the development of a reinforcing ‘cage’ of collagen fibre bundles around the foetal nucleus pulpous. This derives from the fusion of collagen bundles between presumptive end-plate and inner annulus. By birth, the distinct collagenous architectures are established and the disc undergoes considerable enlargement to maturity. We show that fibromodulin plays a prominent role in foetal development of the annulus and its attachment to vertebral bodies. With the exception of keratocan, the other SLRPs appear associated more with cartilage development within the vertebral column, but all become more prominent within the disc during its growth and differentiation.


Article download: Pages 226-241 (PDF file)
DOI: 10.22203/eCM.v022a18