Oral Presentation Matrix Biology Society of Australia and New Zealand Annual Meeting 2012

adamts5, a gene encoding a chondroitin sulphate proteoglycanaseis required for normal patterning during vertebrate embryogenesis (#20)

Carolyn M Dancevic 1 , Nadja Kemmerling 2 , Adam D Smith 1 , Christopher Kintakas 1 , Alister C Ward 1 , Daniel R McCulloch 1
  1. School of Medicine, Deakin University, Geelong, VIC, Australia
  2. School of Mental Health and Neuroscience, Maastricht University , Maastricht, The Netherlands

Background: ADAMTS5 (A Disintegrin-like and Metalloproteinase Domain with Thrombospondin-1 motifs)5 is an extracellular matrix (ECM) remodelling enzyme. ADAMTS5 knockout mice present with partially penetrant soft-tissue syndactyly (webbed feet), due to a lack of interdigital mesenchyme apoptosis during embryogenesis, and enlarged (myxomatous) cardiac valves, demonstrating its diverse role during development. However, there is currently a lack of information regarding the role(s) of ADAMTS5 during early embryonic processes such as gastrulation and neurulation. Because the zebrafish is an ideal model to study genetic interactions occurring in these early stages of development, we used it to gain further insight into potential roles of ADAMTS5 during early embryonic processes. Results: Using a morpholino antisense oligonucleotide approach to silence the highly conserved adamts5 gene1 in zebrafish, we show that adamts5 regulates the expression of key morphogens including Sonic Hedgehog (shh), Bone Morphogenetic Protein-4 and Fibroblast Growth Factor-8 (fgf-8) during gastrulation, through to early somitogenesis. In addition, ADAMTS5 regulates the expression of the skeletal muscle marker myod, downstream of shh, which leads to disrupted skeletal muscle fibre organisation as shown by phalloidin staining of F-actin, as well as in alpha-actin transgenic zebrafish. Neuronal development downstream of the fgf-8 pathway is also disrupted when adamts5 is silenced, indicating a role for ADAMTS5 in the formation of the midbrain-hindbrain boundary. Ski a/b are transcriptional regulators and ski a/b zebrafish morphants displayed a similar phenotype to adamts5 morphants2. Ski a/b interact with Smads-1, -2, -3 and -4, identifying the TGF-β pathway as the potential signalling mechanism disrupted in adamts5 morphants. The addition of exogenous TGF-β rescued the phenotype in ~50% of the adamts5 morphants. Conclusion: Our data demonstrates a pathway through which ADAMTS5 acts during early vertebrate embryogenesis, which may be relevant to other biological and pathological roles whereby ADAMTS5 is implicated.

  1. Brunet, F., Kintakas, C., Smith, A.D. and McCulloch, D.R. (2012).The Function of the Hyalectan Class of Proteoglycans and their Binding Partners during Vertebrate Development (in Advances in Medicine and Biology): Volume 52, NOVA publishers. ISBN: 978-1-62081-314-0.
  2. Kaufman, C. D., G. Martinez-Rodriguez, et al. (2000). "Ectopic expression of c-ski disrupts gastrulation and neural patterning in zebrafish." Mech Dev 95(1-2): 147-162.