A groundbreaking study conducted by the University of California, Irvine has unveiled a previously unknown contributor to the formation of brain hemorrhages that does not involve blood vessel injury. The research team discovered that interactions between aged red blood cells (RBCs) and brain capillaries can lead to cerebral microbleeds, shedding light on the underlying mechanisms and potential therapeutic targets for treatment and prevention.
Published in the Journal of Neuroinflammation, the study utilized advanced imaging techniques to observe the process by which RBCs become stalled in brain capillaries and subsequently trigger hemorrhages. Cerebral microbleeds are often associated with conditions that occur more frequently in older adults, such as hypertension, Alzheimer’s disease, and ischemic stroke.
Co-corresponding author Dr. Mark Fisher, a professor of neurology at UCI’s School of Medicine, emphasized the significance of this study in expanding our understanding of how cerebral microbleeds develop. He stated, “Our findings may have profound clinical implications, as we identified a link between red blood cell damage and cerebral hemorrhages that occurs at the capillary level.”
To investigate this link, the research team exposed RBCs to tert-butyl hydroperoxide, a chemical that induces oxidative stress. The treated RBCs, labeled with a fluorescent marker, were then injected into mice. Through two different imaging methods, the researchers observed the RBCs becoming lodged in brain capillaries and subsequently cleared out via endothelial erythrophagocytosis. As the RBCs were cleared, microglia inflammatory cells engulfed them, leading to the formation of brain hemorrhages.
Co-corresponding author Xiangmin Xu, a UCI professor of anatomy and neurobiology, highlighted the implications of their discoveries, stating, “We need to examine in detail the regulation of brain capillary clearance and analyze how this process relates to insufficient blood supply and ischemic stroke to advance the development of targeted treatments.”
This study marks a significant step forward in uncovering the contributors to brain hemorrhages and offers potential avenues for the development of new therapies. By focusing on the interactions between RBCs and brain capillaries, researchers can further explore the regulation of capillary clearance and its connections to other conditions such as ischemic stroke.
What are cerebral microbleeds?
Cerebral microbleeds refer to small bleeding spots in the brain, often associated with conditions like hypertension, Alzheimer’s disease, and ischemic stroke. These microbleeds occur at a capillary level and were previously believed to be caused solely by blood vessel injury.
What did the study uncover?
The study discovered that interactions between aged red blood cells and brain capillaries can lead to cerebral microbleeds. By exposing red blood cells to oxidative stress and observing their behavior in mouse models, the researchers observed how the red blood cells become stuck in the capillaries and trigger the formation of brain hemorrhages.
What are the implications of these findings?
The findings of this study have significant clinical implications as they provide a new understanding of the development of cerebral microbleeds. Identifying the link between red blood cell damage and brain hemorrhages at the capillary level opens up potential avenues for targeted treatments and prevention strategies.
What further research is needed in this area?
Further research is needed to delve into the regulation of brain capillary clearance and to analyze its connection to insufficient blood supply and ischemic stroke. Understanding these processes can contribute to the development of more effective treatments for conditions associated with cerebral microbleeds.