Characterizing the ageing phenotype of fibroblast populations in the synovium of RA and OA patients

Project No: #OxKEN-2023/13
Intake: OxKEN 2023

project overview

Rheumatoid arthritis (RA) and osteoarthritis (OA) are the most common forms of arthritis in the UK. These conditions have a very high medico-economic cost. Considerable advances in targeted therapy have improved outcomes in RA, yet a notable percentage of affected individuals still experience persistent inflammation and progressive disability, while for OA there is no effective therapy. Recent results demonstrate that resident cells of synovium, known as fibroblast-like synoviocytes (FLS), are not passive bystanders, but actively contribute to the inflammation and degradative processes in RA and OA. Different synovial fibroblast (SF) populations play key roles in mediating inflammation and bone/cartilage destruction. However, little is known about the molecular mechanisms that drive the different fibroblast behaviors observed in RA and OA; specifically, the enrichment of sublining, proinflammatory fibroblasts in RA compared to the enrichment of lining layer pro-destructive fibroblasts in OA. Differences in the cellular makeup of the synovium between RA and OA could be explained by differential ageing phenotype and senescence of SF subsets. Many studies report the negative effect of cellular senescence in SFs and chondrocytes in OA, yet the therapeutic induction of senescence in RA appears to reduce the activation of inflammatory SFs. This project will examine the role of age-related cellular senescence in determining the cellular structure of the synovium. We will use our combined expertise in fibroblast and ageing biology to test the hypothesis that differential senescence in synovial lining layer fibroblast subsets compared to sub-lining subsets underpins the degree of inflammation vs tissue damage between RA and OA.

PROJECT AIMS:
This PhD studentship has three aims:
Aim1: Molecular characterisation of a panel of the ageing hallmark markers in synovial fibroblast lining and sub-lining layer fibroblast subsets in sex-matched patients across ages in OA and RA using different omics approaches.

Aim 2: Establish the anatomical localization of ageing fibroblast subsets in human OA and RA fibroblast synovium compared to inflammatory arthritis (CIA) and destabilisation of the medial meniscus (DMM) synovium using CellDive and RNA scope analysis to measure the ageing hallmark on transcript levels in parallel with the protein levels

Aim 3: Bioinformatic analysis of the relationship between the ageing hallmarks in the lining and sub-lining fibroblasts in human fibroblast subsets compared to subsets analyzed from established mouse models of inflammatory arthritis (CIA) and degenerative arthritis, the destabilization of the medial meniscus (DMM)

keywords

Osteoarthritis, autophagy, ageing, Arthritis, Immunology

training opportunities

The Botnar Research Centre plays host to the University of Oxford's Institute of Musculoskeletal Sciences, which enables and encourages research and education into the causes of musculoskeletal disease and their treatment. Training will be provided in techniques including flow cytometry, histochemistry, confocal microscopy, RNAscope assays, drug screen design and in vitro cell cultures (2D and 3D) of human chondrocytes, fibroblasts, various cell lines as well as using preclinical in vivo models of OA.

A core curriculum of lectures will be taken in the first term to provide a solid foundation in a broad range of subjects including musculoskeletal biology, inflammation, epigenetics, translational immunology, data analysis and the microbiome. Students will also be required to attend regular seminars within the Department and those relevant in the wider University.

Students will be expected to present data regularly in Departmental seminars, Alsaleh’s group and attend external conferences to present their research globally, with limited financial support from the Department.

Students will also have the opportunity to work closely with colleagues in The Centre for Osteoarthritis Pathogenesis Versus Arthritis (OA Centre, https://www.kennedy.ox.ac.uk/oacentre/oacentre), Oxford, DRFZ Institute (https://www.drfz.de/uber-uns/koepfe/prof-dr-max-loehning/), Berlin, TIGEM Institute (https://www.tigem.it/research/faculty/settembre), Naples, and The Buck Institute for ageing research (https://www.buckinstitute.org/lab/campisi-lab/), California.

Students will have access to various courses run by the Medical Sciences Division Skills Training Team and other Departments. All students are required to attend a 2-day Statistical and Experimental Design course at NDORMS (Nuffield Department of Orthopaedics) and run by the IT department (information will be provided once accepted to the programmer).

key publications

Croft, A. P. et al. Distinct fibroblast subsets drive inflammation and damage in arthritis. Nature 570, 246-251, doi:10.1038/s41586-019-1263-7 (2019).
Alsaleh, G. et al. Autophagy in T cells from aged donors is maintained by spermidine and correlates with function and vaccine responses. Elife 9, doi:10.7554/eLife.57950 (2020).
Zhang, H. et al. Polyamines Control eIF5A Hypusination, TFEB Translation, and Autophagy to Reverse B Cell Senescence. Mol Cell 76, 110-125 e119, doi:10.1016/j.molcel.2019.08.005 (2019).
heng, G. et al. TFEB, a potential therapeutic target for osteoarthritis via autophagy regulation. Cell Death Dis 9, 858, doi:10.1038/s41419-018-0909-y (2018).