DiMeN Doctoral Training Partnership: Characterising mechanisms of post-transcriptional gene control for genes that are critical to the healthy ageing of joints

Characterising mechanisms of post-transcriptional gene control for genes that are critical to the healthy ageing of joints.

As our population ages, it is increasingly important that we understand the mechanisms that underpin age-related chronic diseases such as osteoarthritis. This studentship will investigate in detail how key genes associated with osteoarthritis are regulated at the post transcriptional level. The student will determine how rates of mRNA decay and protein translation in cartilage cells affects genes that promote the production and destruction of the highly specialised cartilage extracellular matrix. The appropriately controlled balance of extracellular matrix synthesis and breakdown in cartilage is essential for proper skeletal development and healthy joint function. An imbalance of these processes drives the development of the chronic, age-related joint disease osteoarthritis. The project will have two major focuses.

1. Determine the implications impairing the function of a key anabolic regulator during skeletal development: SOX9 is a transcription factor, which is essential in promoting the expression of extracellular matrix macromolecules in cartilage. Our group has already established that the SOX9 transcript is a relatively short lived mRNA that can be regulated post-transcriptionally probably through interactions with both microRNAs and RNA-binding proteins (McDermott et al. 2016 Osteoarthritis Cartilage 24:1263-73). This part of the project will use in vitro and in vivo approaches to further understand how regulatory regions within the SOX9 mRNA dictate transcript stability and how important these functions are to skeletal development by:
• Employing in vitro reporter approaches to identify regulatory regions within the SOX9 mRNA which are critical to transcript stability
• Using CRSIPR/Cas9 technology to create mouse embryos which have these regulatory regions deleted to determine how altering mRNA stability affects skeletal development in vivo.

2. Define the importance of cis-acting elements in the mRNA of an essential regulator of cartilage catabolism during disease: ADAMTS5 is a proteinase which is able to digest proteoglycans within the cartilage extracellular matrix. Our group has identified ADAMTS5 among a cohort of mRNAs whose rates of mRNA decay in chondrocytes are affected by osteoarthritis (Tew et al. 2014 Arthritis Rheumatol 66:3052-61). ADAMTS5 mRNA has a large 3’UTR, approximately 6kb and although there is some evidence of microRNA regulation there are numerous regulatory elements as well as alternative polyadenylation sites, that we have identified in silico which have not been investigated. In this part of the project, in vitro approaches will be used to:
• Analyse how these elements affect mRNA decay and protein translation
• Identify protein interactions with ADAMTS5 mRNA elements.
• Determine how ADAMTS5 is alternatively polyadenylated, identifying the potential regulatory regions might then be removed because of this.

The student will receive supervision from a team of expert supervisors: Simon Tew and George Bou-Gharios (University of Liverpool) and Julie Aspden (University of Leeds). Training will be provided in a broad range of molecular biological techniques. In addition, the studentship will provide access to a diverse range of additional training opportunities aimed at supporting progression of the PhD and developing transferable skills.

The Institute of Ageing and Chronic Disease is fully committed to promoting gender equality in all activities. In recruitment we emphasize the supportive nature of the working environment and the flexible family support that the University provides. The Institute holds a silver Athena SWAN award in recognition of on-going commitment to ensuring that the Athena SWAN principles are embedded in its activities and strategic initiatives.

Candidates should hold or be expected to obtain a First or Upper Second class Honours degree or a Master’s degree in a relevant Biological subject. If English is not your first language you must have IELTS 6.5 or equivalent, with no component below 5.5."