The role of vascular immune cells in recovery after brain haemorrhage

Intracerebral haemorrhage (ICH) is a stroke subtype caused by spontaneous bleeding into brain tissue. ICH is responsible for over half of the 6.5 million stroke-related deaths annually worldwide and accounts for the majority of the disability burden of stroke, with 80% of ICH patients remaining dependent on others in the long-term1. Despite the considerable and ongoing burden of ICH, there remain few effective therapies to improve outcome and help the brain repair. After ICH there is activation of multiple repair mechanisms including those to stimulate the formation of new blood vessels, which help to restore blood flow and oxygen supply to the damaged brain tissue, and therefore aid in the functional recovery of the blood-brain barrier (BBB). However, despite activation of these regenerative mechanisms, the level of tissue repair is typically insufficient for full restoration of function. Thus, discovering new ways to modulate blood vessel formation and blood flow could be a promising therapeutic strategy after ICH. Perivascular macrophage cells are a small population of specialised macrophages localised around some blood vessels in the brain. Emerging evidence suggest that these perivascular cells may play a role in outcome after stroke2. Our preliminary work has also shown that perivascular macrophages accumulate around the haemorrhage and they might be important in long-term outcome and recovery. This PhD will therefore study the role of these perivascular macrophage cells after ICH and will test the hypothesis that they help to repair the brain vasculature and improve blood flow. To address this hypothesis, the student will use a well-established rodent model of haemorrhage coupled with magnetic resonance imaging (MRI), behavioural tests and ex vivo analysis including analysis of immune cells. This project provides a great opportunity to join a vibrant research group and the student will receive an interdisciplinary training in an exciting area of research which could improve our understanding of a devastating disease and lead to the development of a new treatment option.