Meningothelial cells as part of the central nervous system host defence. (3rd June 2013)

• Record Type: Journal Article
• Authors: Li, Jia; Fang, Lei; Killer, Hanspeter E.; Flammer, Josef; Meyer, Peter; Neutzner, Albert
• Is Part Of: Biology of the cell. Volume 105:Number 7(2013:Jul.)
• Page Start: 304
• Page End: 315
• Publication Date: 2013-06-03
• Subjects: Gram‐positive -- Gram‐negative -- Meningothelial cell -- Phagocytosis -- TLR4; Cytology -- Periodicals; Electron microscopy -- Periodicals; 571.6
• DOI: 10.1111/boc.201300013
• Languages: English
• ISSNs: 0248-4900

Abstract

Abstract : Meningothelial cells or MECs, the cellular component of the brain‐covering meninges, form the interface between neurons and the cerebrospinal fluid. Previously considered to be a passive barrier, MECs are now recognized to play a more active role under physiological and pathophysiological conditions in the brain. Here, MECs express the danger signal receptor TLR4 and are involved in immunological processes in the cerebrospinal fluid through the phagocytosis of bacteria. Abstract : Background Information: Meningothelial cells (MECs) are the cellular components of the meninges protecting the brain and as such provide important barrier function for the central nervous system building the interface between neuronal tissue and the cerebrospinal fluid (CSF). MECs were previously shown to be involved in the clearance of waste products from the CSF and in maintaining the optic nerve microenvironment. In addition, MECs are involved in immunological processes in the brain by secretion of pro‐inflammatory cytokines in response to various pathologically relevant stress conditions. Results: In this study, we analysed the uptake of latex beads as well as bacteria by human MECs using flow cytometric analyses. We found that MECs are highly active phagocytes able of ingesting large amounts of latex beads, as well as Gram‐positive and Gram‐negative bacteria. Phagocytic activity of MECs was sensitive to nocodazole and cytochalasin D treatment to a varying degree depending on particle composition. Interestingly, Gram‐positive bacteria such as Staphylococcus aureus are more readily taken up compared with Gram‐negative Escherichia coli . In addition, pre‐treatment of MECs with lipopolysaccharide (LPS) or phorbol‐12‐myristate‐13‐acetate (PMA) enhanced S. aureus uptake, whereas PMA but not LPS was effective in enhancing E. coli uptake. Conclusions: Thus, MECs are highly active facultative phagocytes likely important for the maintenance of CSF homeostasis and host defence in the central nervous system especially against Gram‐positive bacteria.