Biology subjects

Korte, N.

Publications and source records attributed to Korte, N..

2 recordsLinked to original sources

bioRxiv2022

The Ca2+-gated Cl- channel TMEM16A amplifies capillary pericyte contraction reducing cerebral blood flow after ischemia

Pericyte-mediated capillary constriction decreases cerebral blood flow in stroke after an occluded artery is unblocked. The determinants of pericyte tone are poorly understood. We show that a small rise in cytoplasmic Ca2+ concentration ([Ca2+]i) in pericytes activates chloride efflux through the Ca2+-gated anion channel TMEM16A, thus depolarizing the cell and opening voltage-gated calcium channels. This mechanism strongly amplifies the pericyte [Ca2+]i rise and capillary constriction evoked by contractile agonists and ischemia. In a rodent stroke model, TMEM16A inhibition slows the ischemia-evoked pericyte [Ca2+]i rise, capillary constriction and pericyte death, reduces neutrophil stalling and improves cerebrovascular reperfusion. Genetic analysis implicates altered TMEM16A expression in poor patient recovery from ischemic stroke. Thus, pericyte TMEM16A is a crucial regulator of cerebral capillary function, and a potential therapeutic target for stroke and possibly other disorders of impaired microvascular flow, such as Alzheimers disease and vascular dementia.

physiology↗

bioRxiv2020

Monitoring phagocytic uptake of amyloid β into glial cell lysosomes in real time

Phagocytosis by glial cells is essential to regulate brain function during development and disease. Given recent interest in using amyloid {beta} (A{beta})-targeted antibodies as a therapy for patients with Alzheimers disease, removal of A{beta} by phagocytosis is likely protective early in Alzheimers disease, but remains poorly understood. Impaired phagocytic function of glial cells surrounding A{beta} plaques during later stages in Alzheimers disease likely contributes to worsened disease outcomes, but the underlying mechanisms of how this occurs remain unknown. We have developed a human A{beta}1-42 analogue (A{beta}pH) that exhibits green fluorescence upon internalization into the acidic phagosomes of cells but is non-fluorescent at physiological pH. This allowed us to image, for the first time, glial uptake of A{beta}pH in real time in live animals. Microglia phagocytose more A{beta}pH than astrocytes in culture, in brain slices and in vivo. A{beta}pH can be used to investigate the phagocytic mechanisms removing A{beta} from the extracellular space, and thus could become a useful tool to study A{beta} clearance at different stages of Alzheimers disease.

neuroscience↗