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Long-term consumption of fermented soybean-derived Chungkookjang enhances insulinotropic action unlike soybeans in 90% pancreatectomized diabetic rats.

BACKGROUND: We previously reported that Chungkookjang (CKJ), fermented unsalted soybeans, exhibited better anti-diabetic action than cooked soybeans (CSB) in vitro, but its effectiveness and mechanism have not been studied in vivo. AIM OF THE STUDY: We investigated whether CKJ modulated insulin resistance, insulin secretion, and pancreatic beta-cell growth and survival in 90% pancreatectomized (Px) diabetic rats. METHODS: The Px rats weighing 201 +/- 12 g were divided into four groups and fed for 8 weeks with a CSB diet, a CKJ diet, a casein diet, or a casein diet plus rosiglitazone (20 mg/kg body weight/day). With the exception of protein sources and contents of isoflavonoid aglycones and glycosides, the composition of the diets was made identical by adding soybean oil and cellulose to a casein diet. At the end of the experimental periods, hyperglycemic clamp was performed in conscious, unstressed and overnight fasted Px rats to measure insulin secretion capacity. Insulin/IGF-1 signaling was measured by immunoblotting in isolated islets from the treated rats, and beta-cell mass, proliferation and apoptosis were also determined by immunohistochemistry. RESULTS: After 8-week administration, CSB did not modulate glucose-stimulated insulin secretion, but surprisingly, CKJ enhanced insulin secretion. In addition, CKJ potentiated insulin/IGF-1 signaling in islets via the induction of insulin receptor substrate-2 expression, leading to increasing pancreatic duodenal homeobox-1, insulin promoter transcription factor. In parallel with the enhancement of the signaling, CKJ elevated pancreatic beta-cell hyperplasia by increasing its proliferation and decreasing apoptosis, whereas CSB did not. CONCLUSION: Based on these results, the fermentation of soybeans predominantly with Bacillus subtilis generated isoflavonoid aglycones and small peptides, which improved insulinotropic action in islets of type 2 diabetic rats. Overall, the anti-diabetic action of CKJ was superior to CSB in type 2 diabetic rats.

Animals↗

Fibre utilization by Kalahari dwelling subterranean Damara mole-rats (Cryptomys damarensis) when fed their natural diet of gemsbok cucumber tubers (Acanthosicyos naudinianus).

Kalahari dwelling Damara mole-rats (Cryptomys damarensis) naturally feed on a high fibre diet of underground gemsbok cucumber tubers, Acanthosicyos naudinianus. We investigated the degree of fibre utilization and fermentation on this diet by measuring caecal characteristics (namely temperature, pH and weight) and in vitro rates of gas and short chain fatty acid (SCFA) production in these underground dwelling hind-gut fermentors. Rectal temperatures (33.8 +/- 0.6 degrees C) were consistently higher than caecal temperatures (33.3 +/- 0.6 degrees C). Furthermore, a 0.8 degrees C gradient of temperatures existed within the caecum, with the lowest temperature occurring in the corpus caeci. Both rates of gas production (4.74 +/- 0.6 ml/g dry matter/hr) and SCFA production (266.80 +/- 9.251 mumol/caecum per hr) were high, with proportionately more acetic acid produced than any other SCFA. Nevertheless, the initial concentrations of SCFAs present in the caecum were low (52 +/- 17 mM) implying a rapid rate of absorption of these SCFAs. The high rates of fermentation provide a considerable amount of energy that would otherwise be trapped in fibre and thus unavailable to the animal. This highly efficient caecal fermentation enables the Damara mole-rat to maximally exploit the underground food resources in the arid-zone ecotope.

Animals↗

Site and extent of starch degradation in the dairy cow - a comparison between in vivo, in situ and in vitro measurements.

Prediction of the supply of glycogenic precursors to dairy cows and the site of degradation of wheat, maize and potato starch (PS) were determined in an in vivo experiment and the results were compared with data obtained from experiments involving in situ nylon bag and in vitro gas production techniques. In a Latin square design experiment four lactating dairy cows fitted with a rumen cannula and T-piece cannulae in the duodenum and terminal ileum, received either a low-starch control diet or diets in which sugar beet pulp in the concentrate mixture had been replaced by wheat, maize or PS. Starch from the different sources was almost completely degraded in the total gastrointestinal tract. For all starches, the rumen was the main site of degradation in vivo. No digestion of PS in the small intestine was observed. In situ results suggested that 14% of wheat starch (WS), 47% of maize starch and 34% of PS escaped rumen fermentation. According to the gas production technique WS ferments quickest and potato slowest. PS had a low degradability during the first 8 (gas production) to 11 (in situ) h. However, according to both in vitro and in vivo measurements rumen degradability of PS was high. The results suggest that in situ and in vitro techniques should be performed in animals that have adapted to starch source to provide a more accurate simulation of the in vivo situation.

Animal Feed↗

Polypeptide antibiotic 26a from Bacillus subtilis. III. Physicochemical and biological in vitro properties.

Antibiotic 26a, a weakly basic (pK1 3.85 and pK2 7.1) polypeptide compound, has been recovered from the fermentation fluids of bacillus subtilis cultures as hydrochloride salt easily soluble in water and dimethylsulphoxide, sparingly soluble in lower alcohols and insoluble in several organic solvents. At low concentrations 26a was effective against gram-positive bacteria, mainly micrococci and corynebacteria, moderately active against mycobacteria, and inactive against gram-negative bacteria, yeasts and moulds even at 300 microgram/ml concentration. From the viewpoint of elemental analysis, electrometric titration, optical rotation, UV, IR and NMR spectra, amino acid composition, molecular weight and biological observations, 26a can be considered as an antibiotic, if not identical, then closely related to bacitracin family polypeptides.

Amino Acids↗

The effect of food processing on phytate hydrolysis and availability of iron and zinc.

Phytate is one of the major inhibiting factor for zinc and iron absorption. When phytate is hydrolyzed during the food process the mineral availability is increased. By activation of the endogenous enzyme phytase which is present in plant foods, or addition of phytase, phytate is degraded to various inositolphosphates containing 1-5 phosphate groups per an inositol molecule. The effects of degradation products of phytate on availability of zinc, calcium and iron have to be further investigated. Food processes including soaking, germination and fermentation were under optimal conditions demonstrated to completely reduce the phytate content of cereals and vegetables. The results were related to in vitro measurements of iron availability and human iron and zinc absorption studies.

6-Phytase↗

Effect of microbial fermentation on functional specific gravity of small forage particles.

Two experiments were designed to determine the effect of gas production during in vitro digestion on functional specific gravity (FSG) of forage particles. In Exp. 1, FSG of ground alfalfa hay decreased from 1.123 to 1.049 between 3 and 9 h of incubation and increased thereafter to reach a plateau at 1.309 after 30 h of incubation. Gas production peaked at 6 h, but gas associated with particles increased until 9 h of incubation. Gas associated with solid residue was correlated to gas production (r = -.67) but also was influenced by gas holding capacity and rate of escape from the particles. In Exp. 2, measurements were performed on ground alfalfa hay, alfalfa silage, and bromegrass hay containing 42.6, 35, and 66.4% NDF, respectively. Gas production seemed to be related to the amount of readily available substrate. Although at 9 h of incubation more gas was produced by alfalfa silage (.235 mL.min-1.g of DM-1) than by bromegrass hay and alfalfa hay (.087 and .187 mL.min-1.g of DM-1, respectively), gas associated with particles was greater for alfalfa hay (.416 mL/g of DM) than for bromegrass hay and alfalfa silage (.256 and .281 mL/g of DM, respectively). The increase in FSG was more rapid for alfalfa silage than for the hays. After 27 h of digestion, gas associated with particles (milliliters per gram of DM) and FSG were .164, 1.226; .147, 1.235; and .001, 1.467 for bromegrass hay, alfalfa hay, and alfalfa silage, respectively. Gas produced during fermentation delayed the increase in specific gravity of forage particles.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

The PEL1 gene (renamed PGS1) encodes the phosphatidylglycero-phosphate synthase of Saccharomyces cerevisiae.

Phosphatidylglycerophosphate (PG-P) synthase catalyzes the synthesis of PG-P from CDP-diacylglycerol and sn-glycerol 3-phosphate and functions as the committed and rate-limiting step in the biosynthesis of cardiolipin (CL). In eukaryotic cells, CL is found predominantly in the inner mitochondrial membrane and is generally thought to be an essential component of many mitochondrial functions. We have determined that the PEL1 gene (now renamed PGS1), previously proposed to encode a second phosphatidylserine synthase of yeast (Janitor, M., Jarosch, E., Schweyen, R. J., and Subik, J. (1995) Yeast 13, 1223-1231), in fact encodes a PG-P synthase of Saccharomyces cerevisiae. Overexpression of the PGS1 gene product under the inducible GAL1 promoter resulted in a 14-fold increase in in vitro PG-P synthase activity. Disruption of the PGS1 gene in a haploid strain of yeast did not lead to a loss of viability but did result in a dependence on a fermentable carbon source for growth, a temperature sensitivity for growth, and a petite lethal phenotype. The pgs1 null mutant exhibited no detectable in vitro PG-P synthase activity and no detectable CL or phosphatidylglycerol (PG); significant CL synthase activity was still present. The growth arrest phenotype and lack of PG-P synthase activity of a pgsA null allele of Escherichia coli was corrected by an N-terminal truncated derivative of the yeast PG-P synthase. These results unequivocally demonstrate that the PGS1 gene encodes the major PG-P synthase of yeast and that neither PG nor CL are absolutely essential for cell viability but may be important for normal mitochondrial function.

Amino Acid Sequence↗

Pasta made from durum wheat semolina fermented with selected lactobacilli as a tool for a potential decrease of the gluten intolerance.

A pool of selected lactic acid bacteria was used to ferment durum wheat semolina under liquid conditions. After fermentation, the dough was freeze-dried, mixed with buckwheat flour at a ratio of 3:7, and used to produce the "fusilli" type Italian pasta. Pasta without prefermentation was used as the control. Ingredients and pastas were characterized for compositional analysis. As shown by two-dimensional electrophoresis, 92 of the 130 durum wheat gliadin spots were hydrolyzed almost totally during fermentation by lactic acid bacteria. Mass spectrometry matrix-assisted laser desorption/ionization time-of-flight and reversed phase high-performance liquid chromatography analyses confirmed the hydrolysis of gliadins. As shown by immunological analysis by R5-Western blot, the concentration of gluten decreased from 6280 ppm in the control pasta to 1045 ppm in the pasta fermented with lactic acid bacteria. Gliadins were extracted from fermented and nonfermented durum wheat dough semolina and used to produce a peptic-tryptic (PT) digest for in vitro agglutination tests on cells of human origin. The whole PT digests did not cause agglutination. Affinity chromatography on Sepharose-6-B mannan column separated the PT digests in three fractions. Fraction C showed agglutination activity. The minimal agglutinating activity of fraction C from the PT digest of fermented durum wheat semolina was ca. 80 times higher than that of durum wheat semolina. Pasta was subjected to sensory analysis: The scores for stickiness and firmness were slightly lower than those found for the pasta control. Odor and flavor did not differ between the two types of pasta. These results showed that a pasta biotechnology that uses a prefermentation of durum wheat semolina by selected lactic acid bacteria and tolerated buckwheat flour could be considered as a novel tool to potentially decrease gluten intolerance and the risk of gluten contamination in gluten-free products.

Celiac Disease↗

In vitro bacterial growth and in vivo ruminal microbiota populations associated with bloat in steers grazing wheat forage.

The role of ruminal bacteria in the frothy bloat complex common to cattle grazing winter wheat has not been previously determined. Two experiments, one in vitro and another in vivo, were designed to elucidate the effects of fresh wheat forage on bacterial growth, biofilm complexes, rumen fermentation end products, rumen bacterial diversity, and bloat potential. In Exp. 1, 6 strains of ruminal bacteria (Streptococcus bovis strain 26, Prevotella ruminicola strain 23, Eubacterium ruminantium B1C23, Ruminococcus albus SY3, Fibrobacter succinogenes ssp. S85, and Ruminococcus flavefaciens C94) were used in vitro to determine the effect of soluble plant protein from winter wheat forage on specific bacterial growth rate, biofilm complexes, VFA, and ruminal H2 and CH4 in mono or coculture with Methanobrevibacter smithii. The specific growth rate in plant protein medium containing soluble plant protein (3.27% nitrogen) was measured during a 24-h incubation at 39 degrees C in Hungate tubes under a CO2 gas phase. A monoculture of M. smithii was grown similarly, except under H2:CO2 (1:1), in a basal methanogen growth medium supplemented likewise with soluble plant protein. In Exp. 2, 6 ruminally cannulated steers grazing wheat forage were used to evaluate the influence of bloat on the production of biofilm complexes, ruminal microbial biodiversity patterns, and ruminal fluid protein fractions. In Exp. 1, cultures of R. albus (P < 0.01) and R. flavefaciens (P < 0.05) produced the most H2 among strains and resulted in greater (P < 0.01) CH4 production when cocultured with M. smithii than other coculture combinations. Cultures of S. bovis and E. ruminantium + M. smithii produced the most biofilm mass among strains. In Exp. 2, when diets changed from bermudagrass hay to wheat forage, biofilm production increased (P < 0.01). Biofilm production, concentrations of whole ruminal content (P < 0.01), and cheesecloth filtrate protein fractions (P < 0.05) in the ruminal fluid were greater on d 50 for bloated than for nonbloated steers when grazing wheat forage. The molecular analysis of the 16S rDNA showed that 2 different ruminal microbiota populations developed between bloated and nonbloated animals grazing wheat forage. Bloat in cattle grazing wheat pastures may be caused by increased production of biofilm, resulting from a diet-influenced switch in the rumen bacterial population.

Acetates↗

Bifidobacterium-fermented soy milk extract stimulates hyaluronic acid production in human skin cells and hairless mouse skin.

We examined the effects of Bifidobasterium-fermented (BE) and nonfermented (SME) soy milk extracts on the production of hyaluronic acid (HA) in vitro and in vivo. BE, but not SME, significantly enhanced the production of HA in monolayer and organotypic cultures of human keratinocytes, in cultures of human skin fibroblasts, and in hairless mouse skin following topical application for 2 weeks. In the organotypic cultures formed by a similar structure to human epidermis, BE also extended the distribution of HA. Genistein and daidzein, known to stimulate HA production, were detected in BE at a concentration of 0.18 and 0.07 mM, respectively, but not in SME. Therefore, BE has the potential to enhance HA production in the epidermis and dermis, mainly due to genistein released from its glycoside during fermentation. BE is expected to prevent the age-dependent loss of cutaneous HA.

Administration, Cutaneous↗

How does oxygen inhibit central metabolism in the obligate anaerobe Bacteroides thetaiotaomicron.

The molecular basis of obligate anaerobiosis is not well established. Bacteroides thetaiotaomicron is an opportunistic pathogen that cannot grow in fully aerobic habitats. Because microbial niches reflect features of energy-producing strategies, we suspected that aeration would interfere with its central metabolism. In anaerobic medium, this bacterium fermented carbohydrates to a mixture of succinate, propionate and acetate. When cultures were exposed to air, the formation of succinate and propionate ceased abruptly. In vitro analysis demonstrated that the fumarase of the succinate-propionate pathway contains an iron-sulphur cluster that is sensitive to superoxide. In vivo, fumarase activity fell to < 5% when cells were aerated; virtually all activity was recovered after extracts were chemically treated to rebuild iron-sulphur clusters. Aeration minimally affected the remainder of this pathway. However, aeration reduced pyruvate:ferredoxin oxidoreductase (PFOR), the first enzyme in the acetate fermentation branch, to 3% of its anaerobic activity. This cluster-containing enzyme was damaged in vitro by molecular oxygen but not by superoxide. Thus, aerobic growth is precluded by the vulnerability of these iron-sulphur cluster enzymes to oxidation. Importantly, both enzymes were maintained in a stable, inactive form for long periods in aerobic cells; they were then rapidly repaired when the bacterium was returned to anaerobic medium. This result explains how this pathogen can easily recover from occasional exposure to oxygen.

Bacteroides↗

[In vitro estimation using radioactive phosphorus of the phosphorus requirements of rumen microorganisms].

Microbial requirements for P were assumed to be a function of the amount of microbial protein synthesis (microbial growth) and of the quantity of organic matter (OM) fermented in the rumen. The relationships among P incorporation into microbial matter and protein synthesis, ammonia utilization, volatile fatty acid (VFA) production and organic matter fermented (OMF) were studied in short-term incubations (3 h) using 32P-labelled phosphate. The amount of P incorporated was calculated from extracellular phosphate pool specific activity and the radioactivity incorporated into the microbial sediment during incubation (table 1). The inocula came from sheep fed a protein-free purified diet. In order to vary the intensity of fermentation, carbohydrates with a wide range of degrees of enzymatic susceptibility were used as substrates and the medium was either provided or was deficient in S and trace elements (table 4). Nitrogen was supplied as ammonium salts. Linear regression analyses showed that P incorporation was positively correlated with the criteria of protein synthesis and OM fermentation (figs. 1, 2, 3, 4). However, there was significant phosphorus incorporation when the value for nitrogen incorporation was zero (equation A: (Pi (mg) = 0.162 NH3-N + 0.376; r = 0.9). This was assumed to result either from energetic uncoupling (fermentation without concomitant bacterial growth) or from the lysis of cold microbial cells only. Equation A would reflect total P incorporation and equation A' Pi (mg) = 0.162 NH3-N (mg), net P incorporation. It was assumed that in vitro microbial requirements for P were in the range of 30-70 mg of P/liter of medium for 3-hour incubation, depending on the intensity of fermentation. From a mean value of microbial N yield of 30 g/kg of DOMR (organic matter apparently digested in the rumen), it was calculated that the total and net P requirements in vivo were 6 and 4.9 g/kg of DOMR, respectively, corresponding to 3.9 and 3.2 g/kg of DOM (digestible organic matter). From equation D, relating Pi to OMF, the P requirements were about 4.4 g/kg of DOM. It is suggested that microbial requirements for P varied from 3 to 5 g of P/kg of DOM, depending on the efficiency of microbial synthesis and the extent of carbohydrate fermentation. These results, considered as indicative, should be checked in in vivo experiments.

Animals↗

Prolonged transit time through the stomach and small intestine improves iron dialyzability and uptake in vitro.

The iron dialyzability and uptake in relation to transit time through the stomach and small intestine was investigated using a dynamic in vitro gastrointestinal model in combination with Caco-2 cells. Three test meals were evaluated, consisting of lactic fermented vegetables with white (I) or whole meal bread (II) and of sourdough-fermented rye bread (III). Three transit times were tested (fast, medium, and slow transport). Iron dialyzability and absorption differed significantly between medium and slow transit time for meal I and between fast and medium transit time for meal III. For meal II, high in phytate, the iron dialyzability and absorption were low irrespective of transit time. The meals could be ranked with respect to iron dialyzability and uptake in the order I > III > II. Although the in vitro models used have limitations compared to in vivo experiments, the results suggest that an increased transit time may improve iron availability.

Caco-2 Cells↗

Data model for the elimination of matrix effects in enzyme-based flow-injection systems.

This contribution presents a new conceptional enzyme-based flow injection analysis (FIA) system for the process and quality control of food processing and biotechnological systems. It provides the determination of different analytes in distinct process media on the base of a common experimental set-up. In contrast to known comparable systems, analysis is performed without the commonly used sample preparation and dilution steps. Instead, the adaptation to the necessary measurement range is realized by optimization of intrinsic system parameters. The central principle of the work presented is the elimination of occurring interferences by the heterogeneous matrix of the process sample. Based on a particular injection mode, the application of dehydrogenases as indicator enzymes and a specially developed data model using cognitive methods, cross sensitivities of the detector as well as disturbed reaction rates of the enzymes could be almost completely compensated. Two applications are presented, the analysis of ethanol in non-alcoholic beer and the online determination of D-/L-lactate during a lactic acid fermentation, which reveal the advantage of the developed system.

Alanine Transaminase↗

Monitoring of protein profiles for the optimization of recombinant fermentation processes using public domain databases.

The expression of human superoxide dismutase in fed-batch fermentation of E. coli HMS174(DE3)(pET3ahSOD) was studied as model system. Due to the frequently used strong T7 promoter system a high metabolic load is exerted, which triggers stress response mechanisms and finally leads to the differentiation of the host cell. As a consequence, host cell metabolism is partly shifted from growth to survival accompanied by significant alterations of the protein pattern. In terms of process optimization two-dimensional electrophoresis deserves as a powerful tool to monitor these changes on protein level. For the analysis of samples derived from different states of recombinant protein production wide-range Immobiline Dry Strips pH 3-10 were used. In order to establish an efficient procedure for accelerated process optimization and to avoid costly and time-consuming analysis like mass spectrometry (MS), a database approach for the identification of significant changes of the protein pattern was evaluated. On average, 935 spots per gel were detected, whereby 50 are presumably stress-relevant. Out of these, 24 proteins could be identified by using the SWISS-2DPAGE database (www.expasy.ch/ch2d/). The identified proteins are involved in regulatory networks, energy metabolism, purine and pyrimidine nucleotide synthesis and translation. By this database approach, significant fluctuations of individual proteins in relation to recombinant protein production could be identified. Seven proteins show strong alterations (>100%) directly after induction and can therefore be stated as reliable marker proteins for the assessment of stress response. For distinctive interpretation of this highly specific information, a bioinformatic and statistic tool would be essential in order to perceive the role and contribution of individual proteins in stress response.

Databases, Protein↗

Sodium butyrate differentially modulates plasminogen activator inhibitor type-1, urokinase plasminogen activator, and its receptor in a human colon carcinoma cell.

Human colonic epithelium is exposed to varying levels of sodium butyrate, which is derived from the bacterial fermentation of dietary carbohydrate. Sodium butyrate has several effects on colonic tumor cells in vitro, including arrest of cell growth and differentiation. In the present study we have found that, in addition to a reduction in cellular proliferation, sodium butyrate induces the transient expression of plasminogen activator inhibitor type-1 (PAI-1) in the LIM 2405 human colonic tumor cell. Approximately 40% of the PAI-1 secreted is biologically active as judged by the formation of higher molecular weight, SDS-resistant complexes with urokinase plasminogen activator (uPA). The enhanced PAI-1 biosynthesis was accompanied by an increase in PAI-1 mRNA levels. During the same time period, the amount of secreted uPA remained relatively constant, but the level of cell associated uPA decreased slowly and was accompanied by a decrease in uPA mRNA levels. The uPA receptor is synthesized constitutively by these cells, and was down-regulated at both the protein and mRNA levels in response to sodium butyrate. The results demonstrate that sodium butyrate can alter the balance of components of the plasminogen activator system in a manner which favours net decreased plasminogen activator activity and suggests a role for sodium butyrate in the regulation of extracellular proteolysis.

Base Sequence↗

Design, expression, purification, and application of novel recombinant miR-491 molecules to define the biogenesis and function of miR-491-3p versus -5p in posttranscriptional regulation of UDP-glucuronosyltransferase 1A1.

Interindividual variations in drug metabolism involve various factors, including posttranscriptional gene regulation mechanisms controlled by microRNAs (miRNAs or miRs) derived from the genome. The aim of this study was to use RNA bioengineering technology to produce novel recombinant human miR-491-5p, miR-491-3p, and pre-miR-491 molecules, namely BioRNA/miR-491-5p, BioRNA/miR-491-3p, and BioRNA/pre-miR-491, respectively, and define their functional difference in regulating UDP-glucuronosyltransferase 1A1 (UGT1A1) expression and drug-metabolizing capacity. All 6 BioRNAs were heterologously overexpressed in Escherichia coli (>30% of total RNA) and isolated by fast protein liquid chromatography to high purity (>97%). As BioRNA/pre-miR-491 agents were processed to both 5p and 3p strands in Hep3B and HepG2 cells, BioRNA/miR-491-5p and -3p were selectively processed to 5p and 3p, respectively, and each accumulated to greater levels. Immunoblotting and immunofluorescence studies demonstrated the efficacy of BioRNA/miR-491-3p to suppress UGT1A1 protein levels in Hep3B and HepG2 cells, localized on the endoplasmic reticulum, exhibiting monomeric (&#x223c;55 kDa) and oligomeric (&#x223c;150 kDa) bands under different conditions, whereas BioRNA/pre-miR-491 and miR-491-5p had no effects. Using a fluorescent substrate, N-butyl-4-(4-hydroxyphenyl)-1,8-naphthalimide, lower UGT1A1 drug-metabolizing capacities were found in cells treated with BioRNA/miR-491-3p. In addition, liquid chromatography-tandem mass spectrometry analysis revealed a 45% reduction of estradiol 3-glucuronidation activity by BioRNA/miR-491-3p in Hep3B cells, whereas formation of estradiol 17-glucuronidation mediated by other UGTs was unchanged. Together, these results underline the role of miR-491-3p in regulating UGT1A1 and its impact on cellular drug-metabolizing capacity while demonstrating the applications of recombinant miRNA agents to delineating the importance of posttranscriptional gene regulation in drug metabolism. SIGNIFICANT STATEMENT: Research on posttranscriptional gene regulation mainly uses miRNA mimics chemically synthesized in vitro. This study successfully produced 6 novel recombinant miR-491 molecules through in vivo fermentation with transfer RNA scaffold and transfer RNA-fused pre-miRNA carrier-based technologies, which were further utilized to delineate the biogenesis and function of miR-491-3p versus -5p in modulating UDP-glucuronosyltransferase 1A1 protein levels and drug-metabolizing capacity. The findings demonstrate the role of miR-491-3p in regulating UDP-glucuronosyltransferase 1A1 and value of recombinant miRNA agents for studying drug metabolism.

Humans↗