The expression of TMEM16 scramblases in the neurovascular unit

Abstract

Biological membranes, composed of a double layer of lipids, define the boundaries of living cells and their subcompartments. In eukaryotes, the outer and inner leaflets of the plasma membrane differ in their lipid compositions, with the outer leaflet containing mostly phosphatidylcholine (PC) and sphingolipids, while the inner leaflet is composed of phosphatidylethanolamine (PE), the negatively charged phosphatidylserine (PS), and phosphoinositides. Two classes of ATP‐driven pumps, flippases and floppases, create and maintain the membrane asymmetry, whose rapid collapse occurs during a process called phospholipid scrambling. Members of the TMEM16/ANO family of membrane proteins are Ca2+‐activated phospholipid scramblases and/or Cl− channels. As phospholipid scramblases, they generate key physiological signal by translocating phosphatidylserine (PS), an effector in numerous cell activities such as blood coagulation and the phagocytic clearance of apoptotic cells. Here, we investigated the expression profile of each TMEM16 scramblase in the neurovascular unit (NVU). NVU is a complex functional and anatomical structure composed of endothelial cells, pericytes, smooth muscular and neural cells, including astrocytes, neurons, and interneurons. Also, we investigated the expression of TMEM16 in various brain regions such as cerebral cortex, hippocampus, hypothalamus, medulla, midbrain, etc. The studies on the expression profile of TMEM16 would enhance our understanding the physiological roles of specific TMEM16 scramblase in NVU.Support or Funding InformationThis research was supported by KBRI basic research program through Korea Brain Research Institute funded by Ministry of Science and ICT(20‐BR‐01‐07) and National Research Foundation of Korea (NRF) grant funded by the Korea government(MSIT) (2019R1C1C1002699)