BOSTON The endothelium, the cellular layer lining the body's blood vessels, is extremely resilient. Measuring just a few hundred nanometers in thickness, this super-tenuous structure routinely withstands blood flow, hydrostatic pressure, stretch and tissue compression to create a unique and highly dynamic barrier that maintains the organization necessary to partition tissues from the body's circulatory system.
It's also extremely adaptable. In instances when the barrier must be physically breached to enable immune cells to reach various regions of the body to fight infection, the endothelium cooperates with leukocytes to create openings to provide the infection-fighting cells ready access to their targets. By and large, these ensuing "micro -wounds" are short-lived; as soon as the cells have crossed the endothelium, these pores and gaps quickly heal, restoring the system's efficient barrier function. In cases when these gaps fail to close and leakage occurs the results can be devastating, leading to dramatic pathologies including sepsis and acute lung injury.
The mechanism underlying this highly intuitive capability has not been well understood. Now a research team led by Christopher V. Carman, PhD, of the Center for Vascular Biology Research at Beth Israel Deaconess Medical Center (BIDMC), using a combination of advanced fluorescence imaging and electron microscopy to monitor intracellular signaling dynamics, has amassed real-time information that shows that biomechanical signals are what sets this healing process in motion. Described in The Journal of Cell Biology, the new findings suggest that rather than structural robustness per se, the barrier function of the endothelium relies on an enormous self-restorative capacity. (The JCB Bioinsights video podcast highlights this new discovery. http://jcb-journalclub.rupress.org/2013/05/may_13_2013.ht
|Contact: Bonnie Prescott|
Beth Israel Deaconess Medical Center