Biosynthesis of β-glucuronides of retinol and of retinoic acid in vivo and in vitro

Microbial Metabolism Modulates Antibiotic Susceptibility within the Murine Gut Microbiome

“…Therefore, amoxicillin treatment appears to increase the abundance of transcripts for such substrates, indicating that the microbiota in this state might preferentially utilize host-derived carbohydrates containing alpha-glycosidic bonds. Additionally, this observation supports our earlier finding that amoxicillin treatment increases the expression of genes involved in the degradation of hexuronide and hexuronate, which are common components of animal mucus and bile (Chang et al, 2004;Fabich et al, 2008;Lippel and Olson, 1968;Tutukina et al, 2016). However, amoxicillin also increases the relative transcript abundance of CAZymes utilizing various polysaccharides that typically serve as energy storage molecules (Ná cher-Vá zquez et al, 2017; Peshev and Van den Ende, 2014; Pollock and Cairns, 1991;Wilson et al, 2010); for example, 5 (16.1%) CAZymes that increased during treatment act on fructans, glycogen, starch, or dextran.…”

“…Interestingly, both of these pathways have been previously implicated in bacterial stress responses. In E. coli, putrescine synthesis plays a role in the response to osmotic shock and low pH (Carper et al, 1991;Kashiwagi et al, 1992;Schiller et al, 2000;Schneider et al, 2013), whereas hexuronide degradation is responsible for the catabolism of b-D-glucuronosides that are commonly found in animal mucus and bile (Chang et al, 2004;Fabich et al, 2008;Lippel and Olson, 1968;Tutukina et al, 2016). Conversely, we found that amoxicillin treatment reduced the expression of a number of key central carbon metabolism pathways in relation to controls (Figure 3D; Table S4).…”

Chemical synthesis and growth-promoting activity of all-trans-retinyl β-d-glucuronide

“…Retinoyl fl-glucuronide (I) and retinyl f-glucuronide (II) (Fig. 1) were first identified as prominent biliary metabolites of vitamin A over 20 years ago (Zachman et al, 1966;Lippel & Olson, 1968). Although originally considered primarily as excretion products, they were found to be involved in an enterohepatic circulation (Zachman et al, 1966), and retinoyl glucuronide was shown to stimulate the growth of vitamin A-deficient rats (Nath & Olson, 1967).…”

“…In this regard, all-trans-retinoyl ,glucuronide is highly active in stimulating the differentiation of vaginal epithelia (Sietsema & DeLuca, 1982). Furthermore, 13-cis-retinoic acid, frequently employed in the clinical treatment of skin disorders, readily forms both 13-cis-and all-trans-retinoyl ,glucuronide in several tissues (Lippel & Olson, 1968;Zile et al, 1982;McCormick et al, 1983;Meloche & Besner, 1986). Intracellularly, these retinoid fl-glucuronides are synthesized by the transfer of the glucuronyl moiety from UDP-glucuronic acid by a glucuronyltransferase present in the microsomes (microsomal fractions) of liver (Lippel & Olson, 1968;Miller & De Luca, 1986) and presumably of other tissues.…”

Kleinknotige Leberzirrhose mit ausgeprägter portaler Hypertension als Folge einer Vitamin-A-Intoxikation bei Psoriasis-Behandlung

“…Eine Kumulation des Vitamins bei eingeschränkter Nierenfunktion tritt sehr selten auf, da das glucuronidierte Vitamin bzw. seine Hauptmetaboliten im wesentlichen über die Gallenwege ausgeschieden werden (16,20).…”