Ageing and biology

Investigator

Mark Bagley, School of Chemistry, Cardiff University

Team

Terence Davis, School of Medicine, Cardiff University
Joanna Latimer, School of Social Sciences, Cardiff University
David Kipling, School of Medicine Cardiff University

Contact

Mark Bagley
Email: BagleyMC@cardiff.ac.uk

Background

One of the dynamics of ageing is an increase risk of a variety of age-related diseases such as Alzheimer’s, osteoporosis and diabetes. There is an increasing realisation that an improved understanding of the biology of the normal ageing process will give important insights into what is a major risk factor for these diseases - age itself, giving new opportunities for prevention or therapeutic intervention.

Study of the rare human genetic disease called Werner syndrome (WS), which is associated with premature ageing, provides a very powerful model system to study the biology of normal ageing. WS is associated with more rapid ageing at the cellular level, and in particular an acceleration of replicative senescence - the ageing of dividing cells.

Data has identified a potential role for a stress-signalling pathway in accelerated cell ageing in WS. This pathway, which involves p38 MAP kinase, also has a major role in the regulation of the production of proinflammatory molecules such as cytokines, high levels of which are associated with diseases such as osteoporosis and type II diabetes that are more common in WS patients. This is consistent with a wider hypothesis linking inflammation and ageing - so called “inflamm-ageing”.

The role of p38 suggests this may be a useful therapeutic target in WS and normal ageing but its involvement as a major cellular signalling hub presents major obstacles to its therapeutic utility, such as side effects and toxicity. The downstream kinase MK2 may be a better therapeutic candidate as it has fewer downstream targets and is known to upregulate many inflammatory processes.

Although MK2 activation resulting from UV or genotoxic drugs can induce cellular senescence, prior to the project there was no formal evidence that MK2 plays a causal role in replicative or "stress- induced" senescence via direct experimental intervention.

If premature cell ageing underlies the premature ageing of WS individuals, the study of WS can aid in the understanding of not only how cellular senescence leads to in vivo human ageing, but also in the pathology of age-related inflammatory disease.

Aims and objectives

The aim of this project was to explore the role of MK2 in both replicative and "stress-induced" senescence.

The specific research questions to be addressed were:

Is replicative senescence dependent upon MK2?
Is stress-induced senescence dependent upon MK2?
Is the premature senescence seen in WS cells dependent upon MK2?
What is the ethical and regulatory framework of future human clinical trials?

The ethical dimension of ‘anti-ageing’ science had mainly been focussed on cosmetic and lifestyle anti-aging therapies, rather than anti-ageing science directed at understanding the complex effects of ageing itself as a contributory factor in illness in later life.

A key issue to be explored was the extent to which the degenerations and frailties of later life are a normal part of human life and development, and not a disease as such.

As this work may have been a prelude to the development of therapeutics for an ageing-related disorder, we aimed to explore the ethical and regulatory framework of future human clinical trials.

Design

A combined genetic and small molecule approach: There is no perfect way to modulate cellular signalling through MK2 and thus delineate its role in premature ageing. Thus we adopted a combined genetic and small approach, used successfully in our previous studies towards the role of p38 MAP kinase in accelerated cellular senescence.

A chemical toolkit of MK2 inhibitors: The realisation that MK2 may be a safer drug target has led to much recent activity by pharma to find small molecule MK2 inhibitors as therapeutic agents against chronic inflammatory diseases. These make for an ideal toolkit to establish the role of MK2 in accelerated ageing and, as not commercially available, will be prepared in our chemical laboratories.

A genetic toolkit of MK2 constructs: A series of dominant negative (DN-MK2) and constitutively active (CA-MK2) MK2 genetic constructs were required. For lifespan experiments, retroviral transduction of kinase constructs were used to generate stable integrants.

For short-term transduction, adenoviral constructs were used as these have a high measure of infection, infect most cells in a culture (including non-dividing cells), do not require selection, and thus will result in sufficient cells for analysis.

Outcomes

At the end of the project, we had a greater understanding of the role of the MK2 pathway in normal and WS cell ageing, identified drugs that may form the basis of possible therapeutics for a progeroid syndrome, and perhaps in normal human ageing, and formulated a degree of understanding of the ethical impact of "real" anti-ageing medicine.

As MK2 plays a role in inflammatory disease, and because senescence and inflammageing have both been postulated as contributing to normal ageing, irrespective of the relative contribution of the two mechanisms to the WS phenotype, this syndrome is likely to provide important insights into the mechanism of ageing in normal individuals.

Policy implications

Key findings of the research

This project made a number of scientific discoveries related to Werner syndrome (WS) and the ageing process:

New knowledge and insight into the mechanistic basis of cell ageing in cultured normal and WS cells.
New detailed understanding of the mechanistic basis for premature ageing in WS.
New rapid and efficient chemical routes to MK2 inhibitors.
Gather key scientific data regarding the role of MK2 in cellular senescence in order to underpin future animal and clinical studies.
Test key hypotheses about the mechanistic basis of human ageing.

Product development opportunities include:

The provision of a chemical toolkit of MK2 inhibitors to study the effects of cellular stress signalling on a range of biological problems and clinical conditions.
The provision of a genetic toolkit of MK2 constructs to study the effects of cellular stress signalling on a range of biological problems and clinical conditions.
Pre-clinical trials in a highly representative transgenic mouse model of Werner syndrome through international collaboration.
Human in vivo trials in WS patients to test the contribution of cell senescence and stress signalling pathways to premature ageing.

Key beneficiaries

Key beneficiaries included:

Fellow scientists/social scientists in the fields of ageing
Synthetic and medicinal chemists in academia and the pharmaceutical industry developing routes to related compounds and inhibitors
Pharmaceutical companies and academics working in inflammation research
UK and world-wide population, who are facing the demographic challenges of human ageing
Policy makers who are responsible for the health care of an increasingly aged society