Andrew V Stachulski, Tobias B-A Knausenberger, Sita N Shah, Lesley Hoyles, Simon McArthur
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引用次数: 8
Abstract
The sequential activity of gut microbial and host processes can exert a powerful modulatory influence on dietary components, as exemplified by the metabolism of the amino acids tyrosine and phenylalanine to p-cresol by gut microbes, and then to p-cresol glucuronide (pCG) by host enzymes. Although such glucuronide conjugates are classically thought to be biologically inert, there is accumulating evidence that this may not always be the case. We investigated the activity of pCG, studying its interactions with the cerebral vasculature and the brain in vitro and in vivo. Male C57Bl/6 J mice were used to assess blood-brain barrier (BBB) permeability and whole-brain transcriptomic changes in response to pCG treatment. Effects were then further explored using the human cerebromicrovascular endothelial cell line hCMEC/D3, assessing paracellular permeability, transendothelial electrical resistance and barrier protein expression. Mice exposed to pCG showed reduced BBB permeability and significant changes in whole-brain transcriptome expression. Surprisingly, treatment of hCMEC/D3 cells with pCG had no notable effects until co-administered with bacterial lipopolysaccharide, at which point it was able to prevent the permeabilizing effects of endotoxin. Further analysis suggested that pCG acts as an antagonist at the principal lipopolysaccharide receptor TLR4. The amino acid phase II metabolic product pCG is biologically active at the BBB, antagonizing the effects of constitutively circulating lipopolysaccharide. These data add to the growing literature showing glucuronide conjugates to be more than merely metabolic waste products and highlight the complexity of gut microbe to host communication pathways underlying the gut-brain axis.
期刊介绍:
Tissue Barriers is the first international interdisciplinary journal that focuses on the architecture, biological roles and regulation of tissue barriers and intercellular junctions. We publish high quality peer-reviewed articles that cover a wide range of topics including structure and functions of the diverse and complex tissue barriers that occur across tissue and cell types, including the molecular composition and dynamics of polarized cell junctions and cell-cell interactions during normal homeostasis, injury and disease state. Tissue barrier formation in regenerative medicine and restoration of tissue and organ function is also of interest. Tissue Barriers publishes several categories of articles including: Original Research Papers, Short Communications, Technical Papers, Reviews, Perspectives and Commentaries, Hypothesis and Meeting Reports. Reviews and Perspectives/Commentaries will typically be invited. We also anticipate to publish special issues that are devoted to rapidly developing or controversial areas of research. Suggestions for topics are welcome. Tissue Barriers objectives: Promote interdisciplinary awareness and collaboration between researchers working with epithelial, epidermal and endothelial barriers and to build a broad and cohesive worldwide community of scientists interesting in this exciting field. Comprehend the enormous complexity of tissue barriers and map cross-talks and interactions between their different cellular and non-cellular components. Highlight the roles of tissue barrier dysfunctions in human diseases. Promote understanding and strategies for restoration of tissue barrier formation and function in regenerative medicine. Accelerate a search for pharmacological enhancers of tissue barriers as potential therapeutic agents. Understand and optimize drug delivery across epithelial and endothelial barriers.