Doctoral opportunities

Within the developed world research has consistently demonstrated that social relationships are key to a good quality of life and wellbeing in old age. Loneliness and isolation are two established measures of compromised social relationships and are a significant problem for older people across the developed world with 10% classified as severely lonely and 15% as chronically isolated. We have identified the groups most likely to experience loneliness in later life including those who are widowed, those with fewer material resources and those with poor health. Loneliness and isolation have important negative consequences for both older adults and society being linked with a range of negative health, social and service use outcomes.

Our knowledge the prevalence, risk factors, consequences and loneliness/isolation trajectories outside of the developed world is sparse. Using the wealth of longitudinal studies examining ageing in Brazil including the Bambui and Sao Paulo cohorts, the Brazilian Longitudinal Study of Adult Health (established 2008) and the new Brazilian Longitudinal Study of Health, Ageing and Wellbeing this project will examine the prevalence of loneliness among Brazilian older adults, identify key vulnerability and protective factors, identify key health outcomes linked with loneliness and isolation and map trajectories of loneliness/isolation over time. As the Bambui and Sao Paulo cohorts were established in 1997 and 2003 respectively we will also be able to consider cohort changes in loneliness/isolation within the context of the profound socio-economic change that has characterised Brazil over the last 20 years.

Supervisors: Prof Christina Victor, Dr Jitka Pikhartova

Precursor messenger RNA (pre-mRNA) splicing is a cellular process in which non-coding sequences (introns) are removed and coding sequences (exons) are joined together to generate mRNA for protein production. Splicing is somewhat similar to film editing: if it is not done properly, two unmatched scenes may be stitched together in one episode, which would not make sense. In splicing, if exon-intron boundaries (splice sites) are not correctly identified, the wrong mRNA will be produced from which a faulty protein will be synthesised causing disease. The premature ageing disease, Hutchinson Gilford Progeria Syndrome (HGPS), originates from the mutation in exon 11 of the LMNA gene that creates a splice site which is then mistakenly used leading to production of the truncated protein, named progerin. Small amount of progerin was detected in healthy people raising the hypothesis that, with ageing, the progerin splice site is more often used triggering physiological changes that make us older.

The goal of the project is to identify the proteins that play a key role in modulating the splicing outcomes of two alternative splicing events: (i) aberrant production of progerin, causing HGPS, and (ii) alternative LMNA splicing generating lamin A and C proteins that have partially overlapping functions. Since progerin can be only produced from the pre-mRNA encoding lamin A protein, an ability to force a splicing outcome in favour to lamin C over lamin A can be potentially employed to decrease the amount of progerin. Since the proteins modulating these specific splicing outcomes are likely to affect the speed of the ageing process, the pharmaceutical targeting of these proteins - inhibition of their function by small interacting molecules -- may lead to the discovery of novel drugs capable of slowing the ageing process. Methods: DNA cloning, tissue culture transfections; in vitro pre-mRNA splicing; RNA-protein interactions; real-time PCR.

Supervisor: Dr Evgeny Makarov

TP53 gene encodes the “Tumour Protein” p53 which plays a central role in cell cycle regulation. This protein is widely considered as the “Guardian of the Genome” for maintaining genetic stability. A medical interest to this protein is driven by the fact that about 50% of all human cancers contain mutations in the TP53 gene. We are screening for novel TP53 mutations in the cell line originated from the glioma patients. We have identified the single nucleotide substitution that creates the stop codon which supposed to truncate the protein to one third of its full-length. However, a “full-length” p53 is detected by western blotting in extracts from this cell line. The phenomenon is appeared to be a result of the aberrant pre-mRNA splicing which skips the stop codon.

The aims of this project are to (i) investigate the molecular mechanism of pre-mRNA splicing of the mutant TP53 gene which results in skipping the stop codon and producing a nearly full-length p53 protein; (ii) address the functional roles of the truncated and the single amino acid deletion mutants of p53 in cell cycle regulation and cancerogenesis; and (iii) continue the screening for the mutations in TP53 gene from the glioma patients that could lead to the aberrant pre-mRNA splicing. Methods: DNA cloning, tissue culture, mini-gene pre-mRNA splicing, flow cytometry, fluorescence microscopy, real-time PCR.

Supervisor: Dr Evgeny Makarov

Exosomes are membrane microvesicles that are secreted by many cell types and the tumour cells are thought to generate a larger number of such vesicles. Exosomes contain a large set of the specific RNAs, both mRNAs and microRNAs, which can be delivered into the recipient cells via fusion of the exosome and cellular membranes. The foreign mRNAs can then be translated and the microRNAs can potentially regulate gene expression of the host cell. Thus, exosomes can be considered as the vehicles for transferring genetic information from one cell to another. In this respect, exosomes are likely to be especially employed by the tumour cells to invade the surrounding normal cells with the RNAs which will then deregulate gene expression of the recipient cells making them working in support of the tumour cells.

The first aim is to identify the specific RNA molecules extracted from the exosomes that are released from the tumour cells which can be potentially used for diagnostic or prognosis of certain types of cancer. The exosomes will by purified from the media of cultured cells and their RNA content will be analysed by microarrays, RNA cloning/sequencing and quantitative RT-PCR. The second aim is to investigate whether the shRNAs  inducibly expressed in the genetically engineered human cell lines could be delivered to the recipient cells via exosomes and can cause the functional knockout of the specific gene by a cognate shRNA. The cell lines expressing inducible shRNAs will be generated; the exosomes will be purified from these cells and used to treat the host cells. It is anticipated that the exosomes from the shRNA expressing cells will knock down the corresponding gene causing death of the malignant cells.

Supervisor: Dr Evgeny Makarov

Health reform has led to a prioritisation of self-management, a means whereby people with long term conditions are helped to develop the skills and behaviours required to manage the long term effects of their condition. Significant benefits in terms of personal outcomes as well as resource utilisation have been reported. In line with these developments, self-management following stroke is increasingly accepted as one means of addressing the long term nature of stroke and identified long term unmet needs. However, currently there is no experiential definition of self-management as understood and lived by stroke survivors. There is also limited understanding of contextual influences on self-management despite their recognised influence in other long term conditions. One area of enquiry relates to the role of social support in supporting the development of self-management skills and implementation of effective self-management strategies.
The overall aim of this project is to explore the contextual influences on self-management as experienced by community dwelling stroke survivors over the first year post stroke. This requires exploration of four specific questions. How is self-management understood by stroke survivors? Does their understanding of self-management change over time? What factors are perceived to influence the development and enactment of self-management following stroke?
Do those influences change over time?
These questions could be explored through quantitative or qualitative methods although it is envisaged that a longitudinal qualitative study would be the most appropriate in the first instance. This study has relevance within the UK context but would be equally appropriate to explore within other countries where the use of self-management post stroke is emerging, including Brazil.

Supervisors:

• Dr Meriel Norris
• Prof Christina Victor
• Dr Cherry Kilbride