Development of Next Generation Peptide Location Fingerprinting for Enhanced Characterisation of Skin Ageing and Repair.

In skin, long-lived extracellular matrix (ECM) components in the dermis, and at the dermal-epidermal junction (DEJ) basement membrane, undergo a form of ageing where damage is gradually accumulated to their protein structures by mechanisms such as photo-oxidation (by ultraviolet radiation from the sun) and protease cleavage, leading to profound changes in tissue architecture and function. Identifying key protein targets of this damage, and elucidating the mechanisms and functional consequences, is crucial to understanding ageing and therapeutic development. However, the complexity of tissue makes this challenging.

Peptide location fingerprinting (PLF) is an emerging mass spectrometry (MS) biomarker discovery technology, pioneered by our team, capable of unbiased identification of age-modified proteins in vivo, with potential to identify causal mechanisms and functional consequences. Through the development of the Manchester PLF (MPLF) webtool, this approach has had significant impact in the proteomic characterisation of ageing/diseased tissues over the last five years (six publications), and currently supports ~1500 users.

The first half of this project aims to develop and validate our MPLF webtool, using software engineering and bioinformatics to improve its sensitivity (incorporation of label-free and label intensity measurements), statistical accuracy and data visualisation (3D protein structure model mapping). The second half of the project aims to apply these new capabilities to identify novel potential biomarkers of ageing/photoageing, using spatially resolved proteomic MS datasets of young, aged and peptide bioactive-treated skin from multiple ethnicities, generated through the new 2024 Walgreens Boots Alliance (WBA) Programme. Doing so would answer the following key biological questions:

1. Which are the most susceptible dermal and DEJ basement membrane proteins to damage modifications in ageing/photoageing? 2. How does this impact on their structure and predicted interactions?

3. Can these damage modifications be reversed by treatment with peptide actives developed by the team together with our industrial partners, Boots?