Treating osteoarthritis starts with early detection
Affecting over 25 % of the population over the age of 45, osteoarthritis is a leading cause of pain and disability. Yet, despite its high prevalence, diagnosing and treating this chronic joint disease remains a difficult challenge. But what if there was an indicator that could be identified earlier, well before the disease progresses to a point that makes it challenging to treat? According to the EU-funded TARGETMENISCUS project, that indicator is the degeneration of the knee meniscus. “The meniscus is a key load-distributing tissue in the knee whose degeneration is one of the most potent risk factors for future knee osteoarthritis,” says project coordinator Martin Englund, a researcher at Lund University. Together with a multidisciplinary team of PhD students, postdocs and senior researchers, Englund is leading an effort to gain new knowledge about meniscal degradation in the human knee and the related processes that often precede osteoarthritis.
An important indicator of early-stage osteoarthritis
At the heart of this research are proteomic studies of human menisci and synovial fluid from different stages of osteoarthritis. Also known as joint fluid, synovial fluid is a thick, viscous liquid that lubricates and protects the joints. As such, its contents can serve as an important biomarker for osteoarthritis, as the proteins from the menisci, along with other joint tissue breakdown products, end up in the synovial fluid. To look at the fluid, the project team used mass spectrometry, an analytical technique that measures the mass-to-charge ratio of ions. “Our findings illustrate distinct patterns in protein co-expression, suggesting that the interplay between the protein machinery increases during the early stages of osteoarthritis but is lost as the disease progresses,” explains Englund. According to Englund, the implication of this finding is that, to be successful, osteoarthritis treatments should likely begin at a much earlier stage than previously thought. More details about the project’s findings were published in ‘Molecular & Cellular Proteomics’ and ‘Osteoarthritis and Cartilage Open’, the latter of which won the Publication of the Year Award for Basic Science.
Challenges during the pandemic open new opportunities for osteoarthritis research
In addition to its work on menisci and synovial fluids using mass spectrometry, the project, which received support from the European Research Council, also looked at human knee menisci using various advanced imaging techniques. Due to difficulties conducting clinical knee MRIs of study participants during the pandemic, the project conducted imaging experiments of human tissue samples using micro-CT and ultra-high-field MRI. Although unplanned, the pivot provided some important results. For instance, working in collaboration with the University of Oulu, researchers discovered how the collagen network of the meniscus becomes disorganised as osteoarthritis progresses. It also provided new insights on the calcification of human meniscal tissue, all related to the disease process. “Using human tissue biobanking, advanced proteomic methods, and state-of-the-art imaging techniques, our work continues to push the field forward towards a better understanding of how osteoarthritis evolves, which may result in new treatment strategies,” concludes Englund. To help the public better understand osteoarthritis, the project launched the arthritis portal website.
Keywords
TARGETMENISCUS, osteoarthritis, meniscal degradation, knee, joint disease, disability, mass spectrometry, imaging, meniscal tissue, disease
