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Transport of Protein-Bound Radiotracers Into Tissues*
Published in Lelio G. Colombetti, Biological Transport of Radiotracers, 2020
Two other indole compounds related to tryptophan, melatonin (N-acetyl-5-methox-ytryptamine) and tryptophol (3-indole ethanol), are also bound by albumin. Melatonin is about 60% albumin-bound and 40% free (dialyzable),36 and tryptophol is about 90% albumin-bound and 10% free in vitro.37 However, both the BBB and the liver cell membrane are highly permeable to the lipid-soluble indole compounds. Moreover, virtually all of albumin-bound melatonin is transported into brain or liver and albumin-bound tryptophol freely enters brain.36,37 These results indicate albumin-binding of melatonin or tryptophol has no effect on the in vivo distribution of these compounds.
The Microbiome – Role in Personalized Medicine
Published in David Perlmutter, The Microbiome and the Brain, 2019
It is now widely accepted that the status of the gut microbiome is linked to inflammatory cytokine production and alteration in metabolism. Disturbed gut microbiome composition is commonly referred to as dysbiosis and is linked to the increased production of inflammatory cytokines such as TNF-alpha, IFN-gamma, IL-1 beta, IL-6, and IL-17.37 These inflammatory cytokines are produced in response to the presence of metabolites from a dysbiotic microbiome, including palmitoleic acid metabolism and tryptophan degradation to tryptophol. The bacterial metabolites associated with dysbiosis shape the intestinal immune environment in part by regulating the NLRP6 inflammasome.38 One study of the immunomodulatory effect of 53 individual gut bacterial species found that most gut microbes exerted specialized, complementary, and redundant transcriptional effects. The research team behind this work concluded the following: “Microbial diversity in the gut ensures the robustness of the microbiota’s ability to generate a consistent immunomodulatory impact, serving as a highly important epigenetic system.”39 Imbalances in the composition of the microbiome can result in dysbiosis that can shift the immunomodulatory status into a Th1 dominant state that favors inflammation.
Debaryomyces
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
The transition from yeast-to-mycelium appears to be controlled by quorum sensing (QS), and QS, with ammonia as mediator molecule, is involved in coordination of growth on agar plates in D. hansenii.15 Since alcohol-based mediators are involved in QS-stimulated morphological transitions in Saccharomyces cerevisiae,16 this possibility was investigated also for D. hansenii. D. hansenii CBS 767T was found to possess a high sliding capacity with consequent mat formation on agarized medium. Colony areas at 0.3% agar compared to 2% agar were 23- and 73-fold larger after 3–5 days of growth, and at day 6, D. hansenii CBS 767T had fully covered the 0.3% agar plate. The addition of 1 mM aromatic alcohols phenylethanol, tyrosol, and tryptophol changed the growth pattern of D. hansenii CBS 767T to a more filamentous form that was sometimes observed also for aromatic alcohols concentrations below 1 mM.13
AhR/IL-22 pathway as new target for the treatment of post-infectious irritable bowel syndrome symptoms
Published in Gut Microbes, 2022
Maëva Meynier, Elodie Baudu, Nathalie Rolhion, Manon Defaye, Marjolène Straube, Valentine Daugey, Morgane Modoux, Ivan Wawrzyniak, Frédéric Delbac, Romain Villéger, Mathieu Méleine, Esther Borras Nogues, Catherine Godfraind, Nicolas Barnich, Denis Ardid, Philippe Poirier, Harry Sokol, Jean-Marc Chatel, Philippe Langella, Valérie Livrelli, Mathilde Bonnet, Frédéric Antonio Carvalho
At 24 DPI, fecal AhR activity is significantly reduced in infected group (p < 0.05) (Figure 4A). Trp levels were unchanged between infected and control mice, whatever the studied matrix (serum, feces and caecal content) (Figure S4A). Indole pathway is decreased in serum from infected mice (p < 0.05) (Figure 4B). Deeper-specific analysis of each metabolite showed a significant decrease of tryptophol in feces (p < 0.01) and in caecum (p < 0.05) of infected mice (Figure 4C). AhR activity assay after a stimulation with increasing tryptophol doses showed that this indole metabolite activates AhR (Figure 4D). Kynurenine pathway was significantly increased in serum (p < 0.05) of infected mice but not in feces or cecum (Figure 4E). Even if Trp levels were unchanged, fecal and serum kynurenine/Trp ratio were significantly increased in infected mice (p < 0.05) (Figure 4F). No changes were observed for the serotonin pathway in any compartment (Figure S4B).
Exogenous fungal quorum sensing molecules inhibit planktonic cell growth and modulate filamentation and biofilm formation in the Sporothrix schenckii complex
Published in Biofouling, 2020
Raimunda Sâmia Nogueira Brilhante, Vandbergue Santos Pereira, Augusto Feynman Dias Nobre, Jonathas Sales de Oliveira, Mirele Rodrigues Fernandes, Anderson da Cunha Costa, Anderson Messias Rodrigues, Zoilo Pires de Camargo, Waldemiro Aquino Pereira-Neto, José Júlio Costa Sidrim, Marcos Fábio Gadelha Rocha
Farnesol, 2-phenyilethanol, tyrosol and tryptophol were purchased from Sigma-Aldrich (St Louis, USA) and diluted in methanol (farnesol and 2-phenyilethanol) or water (tyrosol and tryptophol) at a concentration of 2 M (farnesol and 2-phenyilethanol) or 1 M (tyrosol and tryptophol) immediately before use (Cordeiro et al. 2015; Wongsuk and Luplertlop 2020). The antifungal drugs amphotericin B (Sigma-Aldrich, St Louis, USA), itraconazole (Janssen Pharmaceutica, Beerse, Belgium) and terbinafine (Sigma- Aldrich, St Louis, USA) were solubilized in DMSO as recommended in document M38-ed3 (CLSI 2017a) and stored at −20 °C until use.
SARS-CoV-2 infection in nonhuman primates alters the composition and functional activity of the gut microbiota
Published in Gut Microbes, 2021
Harry Sokol, Vanessa Contreras, Pauline Maisonnasse, Aurore Desmons, Benoit Delache, Valentin Sencio, Arnaud Machelart, Angela Brisebarre, Lydie Humbert, Lucie Deryuter, Emilie Gauliard, Severine Heumel, Dominique Rainteau, Nathalie Dereuddre-Bosquet, Elisabeth Menu, Raphael Ho Tsong Fang, Antonin Lamaziere, Loic Brot, Celine Wahl, Cyriane Oeuvray, Nathalie Rolhion, Sylvie Van Der Werf, Stéphanie Ferreira, Roger Le Grand, François Trottein
In the present study, changes in gut microbiota’s composition during experimental COVID-19 translated into several metabolic changes. The SCFA levels were altered during SARS-CoV-2 infection, particularly between day 3 and 13. Changes in SCFA production have been observed during experimental influenza.22 However, it is not yet known whether this alteration impacts gut homeostasis (e.g., inflammation and barrier properties) and secondary systemic outcomes; this topic warrants future studies. Our recent data show that the drop of SCFAs during influenza infection lowers pulmonary defenses and favors secondary bacterial infection in mice.22 The present study is the first to have shown that a respiratory viral infection impacts BA and tryptophan metabolisms. A slight impairment in BA transformation was evidenced at 13 dpi, i.e. concomitantly with the greatest changes in bacterial composition. Moreover, the primary-to-secondary BA ratio (a marker of BA transformation by the gut microbiota) was positively correlated with serum levels of chemokines such as CXCL13. We also observed an increase in the fecal BA level, suggesting that the infection leads to accelerated transit and/or impaired BA reabsorption in the ileum. An increase in the fecal concentration of the tryptophan metabolite tryptamine (known to accelerate transit44–46) was also observed and might have been involved in the increase in fecal BA output. The concomitant overall increase in metabolites from the IDO pathway suggests that the intestine was inflamed to some extent during the course of the infection. Accordingly, the levels of certain individual IDO metabolites and the cumulative levels of all IDO metabolites were positively correlated with systemic markers of inflammation. Conversely, some metabolites from the two other tryptophan metabolism pathways (including 5HT, tryptophol, and tryptamine) were negatively correlated with the markers of inflammation. It remains to be seen whether these alterations in BA and tryptophan metabolism are involved in the severity of a SARS-CoV-2 infection.