Unravelling the role of extracellular nucleosomes, DNA and histones (ExNDH) in the cycle of tissue damage and neuroinflammation in stroke.

forthcoming

Stroke is associated with the death of brain tissue and is a significant cause of mortality and disability among survivors. Tissue necrosis, in addition to the active release of chromatin by activated neutrophils, a process known as NETosis, results in the release of extracellular nucleosomes, DNA, and histones (ExNDH). Such processes serve to exacerbate the initial tissue injury and promote a pro-inflammatory state, thereby amplifying the original injury. The evidence supporting this hypothesis is that the inhibition of histones, the degradation of DNA, the depletion of infiltrated neutrophils and the blocking of NETosis all result in an improvement in the outcome of stroke. While the cellular effects of ExNDH are well documented, there remain significant unanswered questions. It is yet unclear where, when, and how they arise in the extracellular space. Are they sequestered by the extracellular matrix or microvesicles? What is the fate of these substances within the vasculature and the brain parenchyma? What impact do different stroke treatment modalities have on these pathways? The objective of this project is to address these questions in vivo in a systematic manner, thereby filling a significant gap in our understanding of stroke pathophysiology. To approach these matters, I will locally express fluorescent histone protein in the brain of mice using lentiviruses, induce stroke, and track the movement of fluorescent histones using immunofluorescence analysis and two-photon microscopy. By elucidating the distinctive molecular mechanisms that disrupt the detrimental feedback loop of neuronal damage following a stroke, this research has the potential to improve patient treatment. By leveraging my extensive expertise in neuroimmunology and collaborating with the host institute at the forefront of stroke-vascular biology research, I will also be able to contribute to the evolution of new ideas and expand my scientific horizons.