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Investigating the EYE-OPENING POTENTIAL OF TEARS Shakespeare called them the windows to the soul, but scientists believe our eyes – and more particularly, our tears – may also be windows to the brain. Dr Vanessa Morris Associate Professor JoannaWilliams 4 Headlines T he Neurological Foundation has invested $307,444 in a two-year collaboration between researchers at the Universities of Canterbury, Otago and Auckland to discover if tears can be used as an early, non- invasive diagnostic tool for Parkinson’s disease. In a world first, the researchers plan to test tears to assess microRNA levels and also detect abnormal clumping of the alpha-synuclein protein. Currently, the only proven way to confirm the protein clumping that causes Parkinson’s is through cerebrospinal fluid, but that requires invasive methods and is unlikely to become a diagnostic tool. Lead investigator Professor John Dalrymple-Alford, of the University of Canterbury and New Zealand Brain Research Institute (NZBRI) in Christchurch, says the simplicity of collecting tears makes it an ideal initial clinical test that could become part of a regular diagnostic exam. It is well- suited to monitor changes on a regular basis in Parkinson’s or to evaluate potential treatments. “The amazing thing about tears, which is so exciting, is that this humble fluid contains a multitude of biological factors that reflect the person’s overall health and wellbeing.” His Canterbury colleague, protein biochemist Dr VanessaMorris, agrees. “We think the eyes in general, and tears in particular, might be a really rich source of insight into the brain.” The test she will be using involves adding purified healthy alpha-synuclein to a patient’s tear fluid. Tears that contain the abnormal alpha- synuclein quickly convert the healthy protein into clumps that can be detected, whereas the “healthy” tears do not. Another key member of the team, Associate Professor Joanna Williams at Otago, will investigate how the levels of microRNA vary across patients in the study. Joanna says tears are an “under-used biofluid” and many substances in tear fluid have not yet been fully investigated. “That will tell us about the broader cellular processes that might be awry,” she says. “It can provide a biological fingerprint of what is wrong, beyond the influence of alpha-synuclein. If you’ve got abnormal alpha-synuclein we are sure you have the main type of Parkinson’s, but the microRNA might tell us about the variation in how the cells are functioning and be easier targets of intervention.” Participants in the project will include: 80 people with Parkinson’s who are already enrolled in the 17-year