ISGF3 and STAT2/IRF9 Control Basal and IFN-Induced Transcription through Genome-Wide Binding of Phosphorylated and Unphosphorylated Complexes to Common ISRE-Containing ISGs.

In addition to the canonical ISGF3 and non-canonical STAT2/IRF9 complexes, evidence is emerging of the role of their unphosphorylated counterparts in IFN-dependent and -independent ISG transcription. To better understand the relation between ISGF3 and U-ISGF3 and STAT2/IRF9 and U-STAT2/IRF9 in IFN-I-stimulated transcriptional responses, we performed RNA-Seq and ChIP-Seq, in combination with phosphorylation inhibition and antiviral experiments. First, we identified a group of ISRE-containing ISGs that were commonly regulated in IFNα-treated WT and STAT1-KO cells. Thus, in 2fTGH and Huh7.5 WT cells, early and long-term IFNα-inducible transcription and antiviral activity relied on the DNA recruitment of the ISGF3 components STAT1, STAT2 and IRF9 in a phosphorylation- and time-dependent manner. Likewise, in ST2-U3C and Huh-STAT1KO cells lacking STAT1, delayed IFN responses correlated with DNA binding of phosphorylated STAT2/IRF9 but not U-STAT2/IRF9. In addition, comparative experiments in U3C (STAT1-KO) cells overexpressing all the ISGF3 components (ST1-ST2-IRF9-U3C) revealed U-ISGF3 (and possibly U-STAT2/IRF9) chromatin interactions to correlate with phosphorylation-independent ISG transcription and antiviral activity. Together, our data point to the dominant role of the canonical ISGF3 and non-canonical STAT2/IRF9, without a shift to U-ISGF3 or U-STAT2/IRF9, in the regulation of early and prolonged ISG expression and viral protection. At the same time, they suggest the threshold-dependent role of U-ISFG3, and potentially U-STAT2/IRF9, in the regulation of constitutive and possibly long-term IFNα-dependent responses.

Oral administration of oat beta-glucan preparations of different molecular weight results in regulation of genes connected with immune response in peripheral blood of rats with LPS-induced enteritis.

PURPOSE: Beta-glucans are biologically active polysaccharides having antioxidant, immunomodulatory, and antiinflammatory properties. This study investigated the transcriptomic profile in peripheral blood of rats with LPS-induced enteritis, which were fed a diet supplemented with high- (G1) and low- (G2) molecular-weight oat beta-glucans. METHODS: Two-color rat gene expression microarrays were applied and the analysis was performed using a common reference design to provide easy means of comparing samples from various experimental conditions against one another. Common reference sample was labeled with cyanine 3 (Cy3) and investigated samples from each experimental group: C-G0 (control group fed semi-synthetic diet), LPS-G0 (LPS-challenged group fed semi-synthetic diet), LPS-G1 (LPS-challenged group fed G1 beta-glucan enriched diet), and LPS-G2 (LPS-challenged group fed G2 beta-glucan enriched diet) were labeled with cyanine 5 (Cy5). Each microarray was performed in quadruplicate. Statistical analysis was performed using one-way ANOVA and Tukey's HSD post-hoc test (p < 0.05). A multiple testing correction was performed using Benjamini and Hochberg False Discovery Rate < 5%. A quantitative real-time RT-PCR was performed to verify the expression of chosen transcripts. RESULTS: The microarray analyses revealed differentially expressed transcripts between: the LPS-G0 and the control groups: C-G0 (138 genes), the LPS-G1 and LPS-G0 groups (533 genes), and the LPS-G2 and LPS-G0 groups (97 genes). Several differentially expressed genes in the beta-glucan-supplemented groups encoded proteins belonging to TLR and NLR signaling pathways, as well as prostaglandin synthesis and regulation pathways. Both beta-glucans up-regulated the expression of Atg10, which belongs to the family of autophagy-related genes, suggesting a possible link between autophagy induction and beta-glucan supplementation. CONCLUSION: The changes in gene expression observed in the peripheral blood indicate that oat beta-glucans exerted a protective effect in rats with an induced inflammatory state caused by LPS challenge. The greater number of differentially expressed genes was observed in group supplemented with G1 beta-glucan, pointing at the differences in the mode of action of high- and low-molecular-weight beta-glucans in the organism.

Metabolism of strawberry mono- and dimeric ellagitannins in rats fed a diet containing fructo-oligosaccharides.

PURPOSE: We investigated the effects of dietary supplementation with strawberry extracts rich in ETs and fructo-oligosaccharides (FOS) on the intestinal microbiota and the formation of bacterial metabolites in the distal intestine, as well as the absorption of ET metabolites and antioxidant status in rats. METHODS: Rats were allocated into six groups of eight animals each and fed for 4 weeks with a control diet (group C), a control diet supplemented with FOS (group C + FOS) or modifications of these diets, in which a monomeric or dimeric ET-rich extract was added (groups ME and ME + FOS or DE and DE + FOS, respectively). RESULTS: The extract addition, the FOS addition and their interaction significantly affected the total and selected bacterial counts in the caecal digesta (all P < 0.005). The total bacterial count was the highest in group C + FOS, lower in group DE and the lowest in group ME + FOS (10.6, 10.3 and 8.52 log cells/g, respectively; P ≤ 0.05). The total caecal content of ET metabolites was higher in the ME and ME + FOS group than in the DE and DE + FOS group, respectively (67.8 and 89.5 vs. 13.0 and 18.0 µg/g, respectively; P < 0.001). The total plasma concentration of ET metabolites was higher in the ME + FOS and DE + FOS group than in the ME group (248 and 281 vs. 8.13 ng/mL, respectively; P < 0.001). CONCLUSIONS: ETs of the monomeric ET-rich extract are more prone to intestinal breakdown than those of the dimeric ET-rich extract, and absorption of their metabolites can be increased by dietary FOS; however, together, they evoke strong antibacterial activity.

Genome-wide association study of CNVs in 16,000 cases of eight common diseases and 3,000 shared controls.

Copy number variants (CNVs) account for a major proportion of human genetic polymorphism and have been predicted to have an important role in genetic susceptibility to common disease. To address this we undertook a large, direct genome-wide study of association between CNVs and eight common human diseases. Using a purpose-designed array we typed approximately 19,000 individuals into distinct copy-number classes at 3,432 polymorphic CNVs, including an estimated approximately 50% of all common CNVs larger than 500 base pairs. We identified several biological artefacts that lead to false-positive associations, including systematic CNV differences between DNAs derived from blood and cell lines. Association testing and follow-up replication analyses confirmed three loci where CNVs were associated with disease-IRGM for Crohn's disease, HLA for Crohn's disease, rheumatoid arthritis and type 1 diabetes, and TSPAN8 for type 2 diabetes-although in each case the locus had previously been identified in single nucleotide polymorphism (SNP)-based studies, reflecting our observation that most common CNVs that are well-typed on our array are well tagged by SNPs and so have been indirectly explored through SNP studies. We conclude that common CNVs that can be typed on existing platforms are unlikely to contribute greatly to the genetic basis of common human diseases.

STAT2/IRF9 directs a prolonged ISGF3-like transcriptional response and antiviral activity in the absence of STAT1.

Evidence is accumulating for the existence of a signal transducer and activator of transcription 2 (STAT2)/interferon regulatory factor 9 (IRF9)-dependent, STAT1-independent interferon alpha (IFNα) signalling pathway. However, no detailed insight exists into the genome-wide transcriptional regulation and the biological implications of STAT2/IRF9-dependent IFNα signalling as compared with interferon-stimulated gene factor 3 (ISGF3). In STAT1-defeicient U3C cells stably overexpressing human STAT2 (hST2-U3C) and STAT1-deficient murine embryonic fibroblast cells stably overexpressing mouse STAT2 (mST2-MS1KO) we observed that the IFNα-induced expression of 2'-5'-oligoadenylate synthase 2 (OAS2) and interferon-induced protein with tetratricopeptide repeats 1 (Ifit1) correlated with the kinetics of STAT2 phosphorylation, and the presence of a STAT2/IRF9 complex requiring STAT2 phosphorylation and the STAT2 transactivation domain. Subsequent microarray analysis of IFNα-treated wild-type (WT) and STAT1 KO cells overexpressing STAT2 extended our observations and identified ∼120 known antiviral ISRE-containing interferon-stimulated genes (ISGs) commonly up-regulated by STAT2/IRF9 and ISGF3. The STAT2/IRF9-directed expression profile of these IFN-stimulated genes (ISGs) was prolonged as compared with the early and transient response mediated by ISGF3. In addition, we identified a group of 'STAT2/IRF9-specific' ISGs, whose response to IFNα was ISGF3-independent. Finally, STAT2/IRF9 was able to trigger an antiviral response upon encephalomyocarditis virus (EMCV) and vesicular stomatitis Indiana virus (VSV). Our results further prove that IFNα-activated STAT2/IRF9 induces a prolonged ISGF3-like transcriptome and generates an antiviral response in the absence of STAT1. Moreover, the existence of 'STAT2/IRF9-specific' target genes predicts a novel role of STAT2 in IFNα signalling.

Lactic acid fermentation of osmo-dehydrated onion.

The aim of the study was to determine the effect of osmoconcentration in a sucrose and sodium chloride solution on the efficiency of lactic fermentation and the content of polyphenols and oligosaccharides in yellow and red onion varieties: Alonso, Hysky, Hystore, and Red Lady. In most cases, no negative effect of onion dehydration was noted on the growth or number of the bacteria tested. Osmotic dehydration of onions prior to lactic fermentation may positively modify the profile of lactic acid isomers by increasing the proportion of the L (+) isomer. The use of osmotic dehydration before fermentation did not adversely affect the content of polyphenols in the onions. Simultaneously, the loss of fructo-oligosaccharides was limited: 60 % of the initial fructo-oligosaccharide content was obtained using the Alonso cultivar and Levilactobacillus brevis 0944 for onion fermentation.

Effect of Chromium Nanoparticles and Switching from a High-Fat to a Low-Fat Diet on the Cecal Microenvironment in Obese Rats.

Previous studies showed that chromium nanoparticles (Cr-NPs) might be used as dietary compounds against some obesity-related disorders; however, there is little information on how these compounds influence the gut microenvironment. The aim of this study was to investigate whether the negative effects of a high-fat diet in the large intestine of rats might be mitigated by switching to a low-fat diet and supplementation with Cr-NPs. Microbiota sequencing analysis revealed that the main action of the Cr-NPs was focused on changing the gut microbiota's activity. Supplementation with nanoparticles decreased the activity of ß-glucuronidase and enzymes responsible for the hydrolysis of dietary oligosaccharides and, thus, lowered the concentration of short-chain fatty acids in the cecum. In this group, there was also an elevated level of cecal lithocholic acid. The most favorable effect on the regulation of obesity-related disorders was observed when a high-fat diet was switched to a low-fat diet. This dietary change enhanced the production of short-chain fatty acids, reduced the level of secondary bile acids, and increased the microbial taxonomic richness, microbial differences, and microbial enzymatic activity in the cecum. To conclude, supplementation of a high-fat diet with Cr-NPs primarily had an effect on intestinal microbial activity, but switching to a low-fat diet had a powerful, all-encompassing effect on the gut that improved both microbial activity and composition.

The Effects of Dietary Chromium Supplementation along with Discontinuing a High-Fat Diet on the Microbial Enzymatic Activity and the Production of SCFAs in the Faeces of Rats.

The present study assessed the changes in faecal microbial activity in obese Wistar rats fed high-fat or low-fat diets supplemented with various forms of chromium (picolinate or nanoparticles). The 18-week study was divided into two phases: an introductory period (9 weeks; obesity status induction via a high-fat diet) and an experimental period (9 weeks; maintained on a high-fat diet or switched to a low-fat diet and Cr supplementation). During the experimental period (10-18 weeks of feeding), samples of fresh faeces were collected on chosen days. The bacterial enzymatic activity and short-chain fatty acids (SCFAs) concentration were assessed to characterise the dynamism of the changes in faecal microbial metabolic activity under the applied dietary treatments. The results indicated that faecal microbial metabolic activity displayed several adaptation mechanisms in response to modifications in dietary conditions, and a beneficial outcome resulted from a pro-healthy dietary habit change, that is, switching from a high-fat to a low-fat diet. Dietary supplementation with chromium nanoparticles further modulated the aforementioned microbial activity, i.e., diminished the extracellular and total enzymatic activities, while the effect of chromium picolinate addition was negligible. Both the high-fat diet and the addition of chromium nanoparticles reduced SCFA concentrations and increased the faecal pH values.

Independent and population-specific association of risk variants at the IRGM locus with Crohn's disease.

DNA polymorphisms in a region on chromosome 5q33.1 which contains two genes, immunity related GTPase related family, M (IRGM) and zinc finger protein 300 (ZNF300), are associated with Crohn's disease (CD). The deleted allele of a 20 kb copy number variation (CNV) upstream of IRGM was recently shown to be in strong linkage disequilibrium (LD) with the CD-associated single nucleotide polymorphisms and is itself associated with CD (P < 0.01). The deletion was correlated with increased or reduced expression of IRGM in transformed cells in a cell line-dependent manner, and has been proposed as a likely causal variant. We report here that small insertion/deletion polymorphisms in the promoter and 5' untranslated region of IRGM are, together with the CNV, strongly associated with CD (P = 1.37 x 10(-5) to 1.40 x 10(-9)), and that the CNV and the 5'-untranslated region variant -308(GTTT)(5) contribute independently to CD susceptibility (P = 2.6 x 10(-7) and P = 2 x 10(-5), respectively). We also show that the CD risk haplotype is associated with a significant decrease in IRGM expression (P < 10(-12)) in untransformed lymphocytes from CD patients. Further analysis of these variants in a Japanese CD case-control sample and of IRGM expression in HapMap populations revealed that neither the IRGM insertion/deletion polymorphisms nor the CNV was associated with CD or with altered IRGM expression in the Asian population. This suggests that the involvement of the IRGM risk haplotype in the pathogenesis of CD requires gene-gene or gene-environment interactions which are absent in Asian populations, or that none of the variants analysed are causal, and that the true causal variants arose after the European-Asian split.

One-time ozone treatment improves the postharvest quality and antioxidant activity of Actinidia arguta fruit.

The major aim of this study was to check the effect of one-time ozonation on selected quality parameters and antioxidant status of Actinidia arguta fruit. For this purpose, A. arguta fruit was ozonated with gas at a concentration of 10 and 100 ppm, which was carried out successively for 5, 15 and 30 min. Next, the selected quality attributes, antioxidants level as well as NADPH and mitochondrial energy metabolism in mini-kiwi fruit after ozonation were analysed. Our research has shown that ozonation reduced the level of yeast and mould without affecting the content of soluble solids or acidity. In turn, ozonation clearly influenced the antioxidant activity and the redox status of the fruit. The ozonated fruit was characterised by a lower level of ROS due to the higher level of low molecular weight antioxidants, as well as the higher activity of superoxide dismutase and catalase. In addition, improved quality and antioxidant activity of the fruit were indirectly due to improved energy metabolism and NADPH level. The ozonated fruit showed a higher level of ATP, due to both higher activity of succinate dehydrogenase and higher availability of NADH. Moreover, the increased level of NAD+ and the activity of NAD+ kinase and glucose-6-phosphate dehydrogenase contributed to higher levels of NADPH in the fruit.

SARS-CoV-2 infects an in vitro model of the human developing pancreas through endocytosis.

Recent studies showed that SARS-CoV-2 can infect adult human pancreas and trigger pancreatic damage. Here, using human fetal pancreas samples and 3D differentiation of human pluripotent cells into pancreatic endocrine cells, we determined that SARS-CoV-2 receptors ACE2, TMPRSS2, and NRP1 are expressed in precursors of insulin-producing pancreatic ß-cells, rendering them permissive to SARS-CoV-2 infection. We also show that SARS-CoV-2 enters and undergoes efficient replication in human multipotent pancreatic and endocrine progenitors in vitro. Moreover, we investigated mechanisms by which SARS-CoV-2 enters pancreatic cells, and found that ACE2 mediates the entry, while NRP1 and TMPRSS2 do not. Surprisingly, we found that in pancreatic progenitors, SARS-CoV-2 enters cells via cathepsin-dependent endocytosis, which is a different route than in respiratory tract. Therefore, pancreatic spheroids might serve as a model to study candidate drugs for endocytosis-mediated viral entry inhibition and to investigate whether SARS-CoV-2 infection may affect pancreas development, possibly causing lifelong health consequences.

Mitogen Synergy: An Emerging Route to Boosting Human Beta Cell Proliferation.

Decreased number and function of beta cells are a key aspect of diabetes mellitus (diabetes), a disease that remains an onerous global health problem. Means of restoring beta cell mass are urgently being sought as a potential cure for diabetes. Several strategies, such as de novo beta cell derivation via pluripotent stem cell differentiation or mature somatic cell transdifferentiation, have yielded promising results. Beta cell expansion is another promising strategy, rendered challenging by the very low proliferative capacity of beta cells. Many effective mitogens have been identified in rodents, but the vast majority do not have similar mitogenic effects in human beta cells. Extensive research has led to the identification of several human beta cell mitogens, but their efficacy and specificity remain insufficient. An approach based on the simultaneous application of several mitogens has recently emerged and can yield human beta cell proliferation rates of up to 8%. Here, we discuss recent advances in restoration of the beta cell population, focusing on mitogen synergy, and the contribution of RNA-sequencing (RNA-seq) to accelerating the elucidation of signaling pathways in proliferating beta cells and the discovery of novel mitogens. Together, these approaches have taken beta cell research up a level, bringing us closer to a cure for diabetes.

Investigation of Crohn's disease risk loci in ulcerative colitis further defines their molecular relationship.

BACKGROUND & AIMS: Identifying shared and disease-specific susceptibility loci for Crohn's disease (CD) and ulcerative colitis (UC) would help define the biologic relationship between the inflammatory bowel diseases. More than 30 CD susceptibility loci have been identified. These represent important candidate susceptibility loci for UC. Loci discovered by the index genome scans in CD have previously been tested for association with UC, but those identified in the recent meta-analysis await such investigation. Furthermore, the recently identified UC locus at ECM1 requires formal testing for association with CD. METHODS: We analyzed 45 single nucleotide polymorphisms, tagging 29 of the loci recently associated with CD in 2527 UC cases and 4070 population controls. We also genotyped the UC-associated ECM1 variant rs11205387 in 1560 CD patients and 3028 controls. RESULTS: Nine regions showed association with UC at a threshold corrected for the 29 loci tested (P < .0017). The strongest association (P = 4.13 x 10(-8); odds ratio = 1.27) was identified with a 170-kilobase region on chromosome 1q32 that contains 3 genes. We also found association with JAK2 and replicated a recently reported association with STAT3, further implicating the role of this signaling pathway in inflammatory bowel disease. Additional novel UC susceptibility genes were LYRM4 and CDKAL1. Twenty of the loci were not associated with UC, and several appear to be specific to CD. ECM1 variation was not associated with CD. CONCLUSIONS: Collectively, these data help define the genetic relationship between CD and UC and characterize common, as well as disease-specific mechanisms of pathogenesis.

The effect of osmotic dehydration on the polyphenols content in onion.

BACKGROUND: The onion is one of the most popular vegetables in the world, often used in the food industry. The purpose of this work was to determine the effect of osmotic dehydration of onions after storage in solutions containing various amounts of sucrose and sodium chloride on the course of osmoconcentration and the level of polyphenols in the dehydrated vegetables. The results could be useful to define the dehydration conditions under which a product retains the highest content of these health-promoting substances. METHODS: Onions var. Robusta were used. The vegetables were stored for six months at 0°C (air relative humidity 75–80%). They were cut into quarters just before dewatering. Samples of 20 ±1 g were dehydrated for five hours in a 40–60°Bx sucrose solution and a 5–15% NaCl solution (25°C); the weight ratio of the sample to the solution was 1:5. The contents of polyphenols and dry matter were determined. RESULTS: The use of a mixture of two osmotic agents (sucrose, sodium chloride) was more effective in the increase of dry matter content than using only sucrose. Nearly 49% dry matter content in onion was obtained by using a 60% solution (50% sucrose + 10% NaCl) for five hours. The greatest differences in the content of total polyphenols occurred during the first hour. After this time, retention amounted to 48–90%, depending on the concentration of sucrose (40–60%) and sodium chloride (5–15%). The retention of diglycosides of quercetin (mainly quercetin-3,4’-diglucoside) was lower than that of monoglycosides (mainly quercetin-4’- -glucoside). Following dehydration in a solution containing 60% sucrose and 10% NaCl, after three hours, there was about one third of the initial amount of the above-mentioned compounds in onion. CONCLUSIONS: The increase in the concentration of the hypertonic solution, being a mixture of sucrose and sodium chloride, causes a reduction in the retention of total polyphenols in osmotically dehydrated onions. The smallest losses occur after applying a 40% sucrose solution with NaCl up to 10%.

Protocatechuic acid and quercetin glucosides in onions attenuate changes induced by high fat diet in rats.

Yellow onion waste from industrial peeling was used to obtain three pure preparations: protocatechuic acid (PA), quercetin diglycosides (QD) and quercetin monoglycosides (QM). PA contained 61% protocatechuic acid, QD contained 35% quercetin diglucosides, mainly quercetin-3,4'-diglucoside, and QM contained 41% monoglucosides, mainly quercetin-4'-glucoside. The highest antioxidant activity was shown by PA. The effects of preparations on the digestive functions of the gastrointestinal tract of rats as well as the biochemical parameters and antioxidant capacity of the blood in model research on Wistar rats sustained by a high-fat diet were assessed (5 groups per 8 animals). The results of the present experiment showed that different onion phenolic preparations differently modulated the enzymatic activity of faecal (P < 0.001) and caecal (P < 0.001) microbiota. For instance, the QD preparation but not QM efficiently reduced the faecal and caecal bacterial ß-glucuronidase activity. Both protocatechuic acid and quercetin monoglycosides showed a beneficial effect by regulating blood lipids (reduction of TC (P < 0.001) and TG (P < 0.001), non-HDL increase in HDL (P < 0.001)), thereby lowering the risk factors for atherosclerotic lesions AI (P = 0.038) and AII (P = 0.013). In addition, onion phenols showed a strong antioxidant effect, however, with a different mechanism: protocatechuic acid via serum ACL (P = 0.033) increase and hepatic GSSG (P = 0.070) decrease, QM via ACW (P < 0.001) increase and hepatic TBARS (P = 0.002) decrease, and QD via serum ACW increase and hepatic GSSG decrease. It can be concluded that onion polyphenols with a lower molar weight, i.e. QM more preferably affect the blood lipid profile than QD. However QD more efficiently reduced the faecal and caecal bacterial ß-glucuronidase activity.

The origin of in-vitro estrogen-like activity in oregano herb extracts.

Global market of herbs has been struggling with food adulteration issues. A number of assays have been developed to aid the detection of the tampered samples and ensure high quality of the marketed products. However, herbs are marketed not only for their culinary applications but also as remedies due to high levels of biologically active constituents. Nevertheless, there is no information in the literature about the influence of herbs adulteration on the biological activity of the final product. Current study aims at assessing the influence of oregano adulteration on its in-vitro estrogen-like activity. High responses in a mammalian reporter gene assay have been detected in pure and adulterated samples, translating to 21-7409 ng of 17ß-estradiol equivalents per gram of oregano. The origin of those responses was assessed by combining fractionation and UHPLC-HRMS. Three flavones were proposed as the most active extract constituents i.e. luteolin-glucoside, luteolin- and apigenin-glucuronides all of which have been previously identified in other herbal extracts with estrogenic activity. This study underlines challenges of biological activity assessment in complex herbal extracts as well as the need for further assessment of such supplement administrations in the case of postmenopausal women and breast cancer patients undergoing hormone therapy.

A Positive Feedback Amplifier Circuit That Regulates Interferon (IFN)-Stimulated Gene Expression and Controls Type I and Type II IFN Responses.

Interferon (IFN)-I and IFN-II both induce IFN-stimulated gene (ISG) expression through Janus kinase (JAK)-dependent phosphorylation of signal transducer and activator of transcription (STAT) 1 and STAT2. STAT1 homodimers, known as γ-activated factor (GAF), activate transcription in response to all types of IFNs by direct binding to IFN-II activation site (γ-activated sequence)-containing genes. Association of interferon regulatory factor (IRF) 9 with STAT1-STAT2 heterodimers [known as interferon-stimulated gene factor 3 (ISGF3)] or with STAT2 homodimers (STAT2/IRF9) in response to IFN-I, redirects these complexes to a distinct group of target genes harboring the interferon-stimulated response element (ISRE). Similarly, IRF1 regulates expression of ISGs in response to IFN-I and IFN-II by directly binding the ISRE or IRF-responsive element. In addition, evidence is accumulating for an IFN-independent and -dependent role of unphosphorylated STAT1 and STAT2, with or without IRF9, and IRF1 in basal as well as long-term ISG expression. This review provides insight into the existence of an intracellular amplifier circuit regulating ISG expression and controlling long-term cellular responsiveness to IFN-I and IFN-II. The exact timely steps that take place during IFN-activated feedback regulation and the control of ISG transcription and long-term cellular responsiveness to IFN-I and IFN-II is currently not clear. Based on existing literature and our novel data, we predict the existence of a multifaceted intracellular amplifier circuit that depends on unphosphorylated and phosphorylated ISGF3 and GAF complexes and IRF1. In a combinatorial and timely fashion, these complexes mediate prolonged ISG expression and control cellular responsiveness to IFN-I and IFN-II. This proposed intracellular amplifier circuit also provides a molecular explanation for the existing overlap between IFN-I and IFN-II activated ISG expression.

Application of Transgalactosylation Activity of ß-Galactosidase from Kluyveromyces lactis for the Synthesis of Ascorbic Acid Galactoside.

In view of a commonly known beneficial role and low stability of ascorbic acid, many efforts are constantly undertaken to produce its improved derivatives. This paper presents results on the synthesis of ascorbic acid galactoside using transgalactosylation properties of ß-galactosidase from Kluyveromyces lactis and lactose as a donor of galactosyl moiety. The purpose of this study was to determine the influence of selected factors (concentration and molar ratio of substrates, amount of the enzyme preparation, pH of the solution, presence of different ions) on the course of transgalactosylation reaction. Research has shown that approx. 2.5% dry matter (d.m.; 12.7 g/L) of ascorbic acid galactoside is formed under favourable conditions (50% (w/v) substrates, sodium ascorbate and lactose at the molar ratio of 1.9:1, enzyme dose of 28,600 U/100 g lactose, pH = 7.0). The addition of Mg2+ or K+ ions to the reaction medium caused an increase in the final product content (even up to approx. 3.4% d.m., 17.2 g/L), while Na+ or Mn2+ had an adverse impact on the yield. The gathered data may be valuable for cosmetic or food industry.

Onion quercetin monoglycosides alter microbial activity and increase antioxidant capacity.

The effects on fermentation processes in the digestive tract, the biochemical parameters and antioxidant capacity of blood in rats fed high-fat diets with quercetin (Q) and quercetin with quercetin monoglycosides (Q+MQ) preparations obtained from onion waste were evaluated. Four groups of eight animals were fed for 4 weeks with a control diet (C), a high-fat diet (HF) and high-fat diets with 0.15% addition of Q and Q+MQ preparations. HF caused an increase in alanine transaminase (ALT), non-high-density lipoprotein (non-HDL) and the atherogenic index AII vs. C and a decrease in the proportion of HDL in total cholesterol (TC). Q and Q+MQ showed a tendency to moderate the values aspartate transaminase (P=.087), ALT (P<.05), TC (P=.068), non-HDL cholesterol (P<.05), triglycerides (P=.064) and the atherogenic index AII (P<.05). Q+MQ significantly increased the activity of α-glucosidase (P<.05 vs. HF), ß-glucosidase (P<.05) and ß-galactosidase (P<.05 vs. C and Q). Q increased activity of ß-glucosidase (P<.001 vs. C and HF). Both increased the activity of ß-glucuronidase (P<.05 vs. C and HF). Both increased the antioxidant capacity of the hydrophilic fraction in serum (P<.05 vs. C and HF), and Q enhanced that of the lipid fraction (P<.001). Q preparation contained 70% quercetin, and Q+MQ preparation contained 29% quercetin and 13% quercetin monoglycosides, mainly quercetin-4'-glucoside. Both exhibited high antioxidant capacity. Supplementation with Q and Q+MQ increased the enzymatic activity of the intestinal microbiota and the antioxidant capacity of blood and revealed a tendency to improve the blood lipid profile. MQ were particularly effective in stimulating the bacterial enzymatic activity.