Dietary pectin and inulin: a promising adjuvant supplement for collagen-induced arthritis through gut microbiome restoration and CD4+ T cell reconstitution.

Dietary strategies rich in fiber have been demonstrated to offer benefits to individuals afflicted with rheumatoid arthritis (RA). However, the specific mechanisms through which a high-fiber diet (HFD) mitigates RA's autoimmunity remain elusive. Herein, we investigate the influence of pectin- and inulin-rich HFD on collagen-induced arthritis (CIA). We establish that HFD significantly alleviates arthritis in CIA mice by regulating the Th17/Treg balance. The rectification of aberrant T cell differentiation by the HFD is linked to the modulation of gut microbiota, augmenting the abundance of butyrate in feces. Concurrently, adding butyrate to the drinking water mirrors the HFD's impact on ameliorating CIA, encompassing arthritis mitigation, regulating intestinal barrier integrity, and restoring the Th17/Treg equilibrium. Butyrate reshapes the metabolic profile of CD4+ T cells in an AMPK-dependent manner. Our research underscores the importance of dietary interventions in rectifying gut microbiota for RA management and offers an explanation of how diet-derived microbial metabolites influence RA's immune-inflammatory-reaction.

Assessing the causal relationships of gut microbial genera with hyperuricemia and gout using two-sample Mendelian randomization.

BACKGROUND AND AIMS: The causal relationship between gut microbiota and gout and hyperuricemia (HUA) has not been clarified. The objective of this research was to evaluate the potential causal effects of gut microbiota on HUA and gout using a two-sample Mendelian randomization (MR) approach. METHODS AND RESULTS: Genetic instruments were selected using summary statistics from genome-wide association studies (GWASs) comprising a substantial number of individuals, including 18,473 participants for gut microbiome, 288,649 for serum urate (SU), and 763,813 for gout. Two-sample MR analyses were performed to determine the possible causal associations of gut microbial genera with the risk of HUA and gout using the inverse-variance weighted (IVW) method, and robustness of the results was confirmed by several sensitivity analyses. A reverse MR analysis was conducted on the bacterial taxa that were identified in forward MR analysis. Based on the results of MR analyses, Escherichia-Shigella (OR = 1.05; 95% CI, 1.01-1.08; P = 0.009) exhibited a positive association with SU levels, while Lachnospiraceae NC2004 group (OR = 0.95; 95% CI, 0.92-0.98; P = 0.001) and Family XIII AD3011 group (OR = 0.94; 95% CI, 0.90-0.99; P = 0.015) were associated with a reduced HUA risk. Moreover, Coprococcus 3 (OR = 1.17, 95% CI: 1.01-1.34, P = 0.031) was causally associated with a higher gout risk. In reverse MR analysis, no causal relationships were identified between these bacterial genera and HUA or gout. CONCLUSION: This study provides evidence for a causal association between gut microbial genera and HUA or gout, and further investigations of the underlying mechanism are warranted.

Integrated network pharmacology and gut microbiome analysis to reveal the mechanism of Qu-Zhuo-Tong-Bi decoction against hyperuricemia and gout.

ETHNOPHARMACOLOGICAL RELEVANCE: Qu-zhuo-tong-bi decoction (QZTBD) is a classic Chinese herbal medicine that has shown therapeutic efficacy in clinical practice against hyperuricemia and gout. However, the potential mechanisms of QZTBD remain poorly investigated. AIM OF THE STUDY: To assess the therapeutic effects of QZTBD on hyperuricemia and gout and to reveal its mechanisms of action. MATERIALS AND METHODS: A Uox-KO mouse model of hyperuricemia and gout was established, and QZTBD was administered at a dosage of 18.0 g/kg/d. Throughout the experimental period, the effects of QZTBD on gout symptoms were monitored and analyzed. The integrated network pharmacology and gut microbiota analysis strategy was conducted to explore the mechanism of QZTBD in the treatment of hyperuricemia and gout. Targeted metabolomic analysis was performed to investigate the variation of amino acids and Spearman's rank correlation analysis was conducted to reveal the relationship between the discrepant bacterial genera and the altered amino acid. Flow cytometry was utilized to analysis the proportion of Th17 and Treg cells, and the production of pro-inflammatory cytokines was measured by ELISA. qRT-PCR and Western blot assay were applied to detect the expression of mRNA and protein respectively. Autodock vina 1.1.2 was used to evaluate the docking interactions. RESULTS: QZTBD treatment showed remarkable efficacy against hyperuricemia and gout with respect to attenuation of disease activity metrics through gut microbiome recovery and intestinal immune homeostasis. The administration of QZTBD significantly elevated the abundance of Allobaculum and Candidatus sacchairmonas, corrected the aberrant amino acid patterns, repaired the impaired intestinal barrier, restored the balance of Th17/Treg cells via PI3K-AKT-mTOR pathway, and reduced the levels of inflammatory cytokines such as IL-1ß, IL-6, TNF-α and IL-17. Fecal microbiota transplantation from QZTBD treated mice demonstrated convincing evidence of efficacy and mechanism of QZTBD. CONCLUSION: Taken together, our study explores the therapeutic mechanism of an effective herbal formula, QZTBD, for gout treatment through remodeling gut microbiome and regulating the differentiation of CD4+ T cells via PI3K-AKT-mTOR pathway.

Shenhuang plaster ameliorates the Inflammation of postoperative ileus through inhibiting PI3K/Akt/NF-κB pathway.

BACKGROUND: Although Shenhuang plaster (SHP) from traditional Chinese medicine prescriptions, has the potential to promote the recovery progression of postoperative ileus (POI), the underlying mechanism remains elusive. Along these lines, in this work, both in vivo and in vitro studies were conducted to systematically explore the regulatory effect and mechanism of SHP on the inflammatory response of the intestinal basal layer in the POI model mice. METHODS: Intestinal manipulation in mice was utilized for the POI model. The impact of SHP in response to POI was evaluated by carrying fluorescein-labeled dextran, histomorphology, immunohistochemistry, in combination with flow cytometry analysis and transcriptome RNA sequencing in vivo. Besides, the cytotoxicity of the SHP treatment on RAW264.7 cells was detected by cell counting kit-8 (CCK-8), the biological effects were assessed by polymerase chain reaction (PCR) and the potential influences on the PI3K/Akt/NF-κB pathway were identified through detecting the expression levels of P85, AKT, IKK and P65 by western blot in vitro. RESULTS: The implementation of the SHP treatment could significantly reduce the expressions of interleukin (IL)- 1ß and tumor necrosis factor (TNF)-α in the intestine, whereas the recovery of gastrointestinal motility is promoted. In addition, SHP can regulate the polarization of macrophages, indicating that the proportion of the M2 type is increased after the application of the SHP treatment. In addition, SHP inhibited the activity of PI3K/AKT/NF-κB signaling pathway-related proteins. CONCLUSION: SHP can significantly ameliorate the inflammatory response of POI and at the same time promote the recovery of gastrointestinal motility. Its mechanism may be mediated by the polarization of macrophages through the PI3K/AKT/NF-κB signaling pathway.

TENT2, TUT4, and TUT7 selectively regulate miRNA sequence and abundance.

TENTs generate miRNA isoforms by 3' tailing. However, little is known about how tailing regulates miRNA function. Here, we generate isogenic HEK293T cell lines in which TENT2, TUT4 and TUT7 are knocked out individually or in combination. Together with rescue experiments, we characterize TENT-specific effects by deep sequencing, Northern blot and in vitro assays. We find that 3' tailing is not random but highly specific. In addition to its known adenylation, TENT2 contributes to guanylation and uridylation on mature miRNAs. TUT4 uridylates most miRNAs whereas TUT7 is dispensable. Removing adenylation has a marginal impact on miRNA levels. By contrast, abolishing uridylation leads to dysregulation of a set of miRNAs. Besides let-7, miR-181b and miR-222 are negatively regulated by TUT4/7 via distinct mechanisms while the miR-888 cluster is upregulated specifically by TUT7. Our results uncover the selective actions of TENTs in generating 3' isomiRs and pave the way to investigate their functions.

Alteration of Gut Microbiome and Correlated Amino Acid Metabolism Contribute to Hyperuricemia and Th17-Driven Inflammation in Uox-KO Mice.

Although gut dysbiosis had been demonstrated to be an important factor affecting hyperuricemia (HUA) and gout, little is known for its potential mechanistic connections. In this study, Uox-KO mice model that with spontaneously developed pronounced HUA and urate nephropathy was used to explore the pathophysiologic mechanism of microbiota alterations in HUA and gout with integrated multi-omics analysis. 16S rRNA gene sequencing was performed to characterize the characteristic bacteria, and untargeted LC/MS analysis was applied to reveal the featured metabolites. Our results showed there was a significant shift in gut microbiota composition and function in Uox-KO mice compared to WT mice and apparent metabolomics differences between the two groups. Among them, amino acids metabolism appears to play a critical role. Correlation analysis further revealed that the characteristic metabolites were strongly influenced by the discrepant bacterial genera. Furthermore, impairment of intestinal integrity and profound alterations in the profile of solute carrier family resulted in dysregulation of amino acids transportation, which subsequently impacted serum uric acid level and CD4+ Th17 driven inflammation. Together, these data indicate that gut dysbiosis promotes purine metabolism disorder and inflammation in Uox-KO mice. Remodeling the gut microbiota is a promising strategy to combat HUA and gout.

The Flavonoid Naringenin Alleviates Collagen-Induced Arthritis through Curbing the Migration and Polarization of CD4+ T Lymphocyte Driven by Regulating Mitochondrial Fission.

Rheumatoid arthritis (RA) is a progressive autoimmune disease. Due to local infiltration and damage to the joints, activated CD4+ T cells play a crucial role in the progression of RA. However, the exact regulatory mechanisms are perplexing, which makes the effective management of RA frustrating. This study aimed to investigate the effect of mitochondria fission on the polarization and migration of CD4+ T cells as well as the regulatory mechanism of NAR, so as to provide enlightenment on therapeutic targets and novel strategies for the treatment of RA. In this study, a collagen-induced arthritis (CIA) model was established, and rats were randomly given saline or naringenin (NAR, 10 mg/kg, 20 mg/kg, 50 mg/kg, i.p.) once a day, before being euthanized on the 42nd day of primary immunization. The pain-like behavior, articular index scores, account of synovial-infiltrated CD4+ T cells, and inflammatory factors were investigated in each group. In vitro, spleen CD4+ T lymphocytes were derived from each group. In addition, mitochondrial division inhibitor 1 (Mdivi-1) or NAR was added to the cell medium containing C-X-C motif chemokine ligand 12 (CXCL12) in order to induce CD4+ T lymphocytes, respectively. The polarization capacity of CD4+ T cells was evaluated through the immunofluorescence intensity of the F-actin and myosin light chain phosphorylated at Ser19 (pMLC S19), and the mitochondrial distribution was determined by co-localization analysis of the translocase of outer mitochondrial membrane 20 (TOM20, the mitochondrial marker) and intercellular adhesion molecule 1 (ICAM1, the uropod marker). The mitochondrial fission was investigated by detecting dynamin-related protein 1 (Drp1) and mitochondrial fission protein 1 (Fis1) using Western blot and immunofluorescence. This study revealed that high-dose NAR (50 mg/kg, i.p.) alleviated pain-like behavior and articular index scores, reduced the serum level of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), and accounted for CD4+ T lymphocytes that infiltrated into the synovial membrane of the CIA group. Meanwhile, NAR (50 mg/kg, i.p.) suppressed the polarization of spleen CD4+ T lymphocytes, reduced the redistribution of mitochondria in the uropod, and inhibited the expression of Drp1 and Fis1 in the CIA model. Furthermore, the in vitro experiments confirmed that NAR reduced mitochondrial fission, which in turn inhibited the CXCL12-induced polarization and migration of CD4+ T lymphocytes. Our results demonstrated that the flavonoid NAR was a promising drug for the treatment of RA, which could effectively interfere with mitochondrial fission, thus inhibiting the polarization and migration of CD4+ T cells in the synovial membrane.

Altered oral microbiota composition associated with recurrent aphthous stomatitis in young females.

ABSTRACT: Oral microbiota has been implicated in pathogenesis of recurrent aphthous stomatitis (RAS), which is a common mucosal disorder with unclear etiology. This study has explored the association between oral microbiota disorder and RAS in high-risk young female population.Forty-five young females were enrolled, including 24 RAS patients and 21 healthy individuals. Oral microbiome was analyzed by Illumina Miseq sequencing.Oral microbiota associated with RAS was characterized by the lower alpha-diversity indices (Chao1 and ACE). Several infectious pathogens increased in RAS, such as genera Actinobacillus, Haemophilus, Prevotella and Vibrio. The PICRUSt analysis indicated that the oral microbiota might be related with the up-regulation of genes involving infectious and neurodegenerative diseases, environmental adaptation, the down-regulation of genes involving basal metabolism, such as carbohydrate, energy, and amino acid metabolism.This study indicated that oral microbiota may play a significant role in RAS development.

Combined effects of MSU crystals injection and high fat-diet feeding on the establishment of a gout model in C57BL/6 mice.

OBJECTIVE: Gout is characterized by inflammatory arthritis with hyperuricaemia and deposition of monosodium urate (MSU) crystals in the joints. Several animal models have been proposed based on MSU crystals injection or high-fat diet feeding; however, neither hyperuricaemia model nor acute gout model can effectively reflect clinical features of gout. This study aimed to assess the effectiveness of a compound gout model induced by the combination of MSU crystals injection and high-fat diet feeding. METHODS: The compound gout model was induced by high-fat diet feeding per day and the intraplantar injection of MSU crystals (1 mg) into the footpad of each mouse every 10 days. Serum uric acid, foot swelling and pain analyses were performed at days 22, 32 and 42. Gout inflammation, serum proinflammatory cytokines and gut microbiota analyses were performed only at day 42. RESULTS: Compared to hyperuricaemia model or acute gout model, the compound gout model showed little advantages of elevating serum uric acid, causing foot swelling and gout inflammation, while it caused more severe serum inflammation and gut microbiota dysbiosis. Severe serum inflammation in the compound gout model could be reflected by the increased levels of IL-1α, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, IFN-γ, KC, MCP-1 and MIP-1ß. In addition, the compound gout model induced more alterations in the gut microbiota, including increasing levels of Desulfovibrio and Parasutterella. CONCLUSION: The injection of MSU and feed of high-fat diet have a combined effect on elevating serum inflammation and causing gut microbiota disorders in the process of establishing a gout model.

Simiao Decoction Alleviates Gouty Arthritis by Modulating Proinflammatory Cytokines and the Gut Ecosystem.

Simiao decoction, a classical traditional Chinese medicine (TCM) formula, has been widely used for thousands of years due to its safety and efficiency in treating gouty arthritis. Utilizing serum proinflammatory cytokines and gut ecosystems, this study elucidated the mechanisms of alleviating gouty arthritis by Simiao decoction. Simiao decoction (4.0, 8.0, and 16.0 g/kg) was orally administered to gouty arthritis mice and febuxostat was given as a positive control. The spleen, kidney, and liver indexes indicated that Simiao decoction was safe for the treatment of gouty arthritis in C57BL/6 mice. Besides, our study demonstrated that Simiao decoction was effective for reducing the level of serum uric acid and decreasing MPO, XOD, and ADA activity, as well as alleviating gouty-related symptoms, such as foot swelling and pain. Moreover, Simiao decoction could also reduce some specific serum proinflammatory cytokines including IL-1ß, IL-9, IFN-γ, MIP-1α and MIP-1ß. We then surveyed the effects of Simiao decoction on the gut ecosystems in a systematic manner by combining network pharmacology, ELISA, western blot, and illumina sequencing. In the murine of model of gouty arthritis, Simiao decoction could suppress NLRP3 inflammasomes expression, reduce gut apoptosis through modulating TNF-α, Caspase 8, and AIFM1 protein expressions, affect lipid metabolism by regulating APOB, LPL, PPARα protein expressions and restore gut microbiota via reducing potential pathogens. Overall, these findings suggested that Simiao decoction was an effective therapeutic drug for gouty arthritis and the gut ecosystem might act as a potential anti-inflammatory target of Simiao decoction.

AGO-bound mature miRNAs are oligouridylated by TUTs and subsequently degraded by DIS3L2.

MicroRNAs (miRNAs) associated with Argonaute proteins (AGOs) regulate gene expression in mammals. miRNA 3' ends are subject to frequent sequence modifications, which have been proposed to affect miRNA stability. However, the underlying mechanism is not well understood. Here, by genetic and biochemical studies as well as deep sequencing analyses, we find that AGO mutations disrupting miRNA 3' binding are sufficient to trigger extensive miRNA 3' modifications in HEK293T cells and in cancer patients. Comparing these modifications in TUT4, TUT7 and DIS3L2 knockout cells, we find that TUT7 is more robust than TUT4 in oligouridylating mature miRNAs, which in turn leads to their degradation by the DIS3L2 exonuclease. Our findings indicate a decay machinery removing AGO-associated miRNAs with an exposed 3' end. A set of endogenous miRNAs including miR-7, miR-222 and miR-769 are targeted by this machinery presumably due to target-directed miRNA degradation.

Effect of a Traditional Chinese Medicine Formula (CoTOL) on Serum Uric Acid and Intestinal Flora in Obese Hyperuricemic Mice Inoculated with Intestinal Bacteria.

CoTOL is a traditional Chinese medicine (TCM) formula in clinics for treating gout and hyperuricemia, especially in obese patients with recurrent attacks. However, fewer studies have investigated how CoTOL impacts the intestinal flora in reducing uric acid. In the present, we analyze the bacteria targeted by ingredients of CoTOL and evaluate the effects of CoTOL on uric acid and intestinal flora in a mice model of obese hyperuricemia inoculated with xanthine dehydrogenase- (XOD-) producing bacteria, Streptococcus faecalis. Firstly, ingredients of herbs in CoTOL and gene target by these ingredients were retrieved from TCMID 2.0, and these genes were screened by DAVID Bioinformatics Resources 6.8, deciphered to retrieve the bacteria. Then, 3-4-week-old male C57bl/6j mice were randomly divided into 6 groups and fed with high fat diet for 8 weeks up to obesity standard. The mice were inoculated intragastrically with 5 × 109 CFU Streptococcus faecalis 3 times at the 5th, 6th, and 7th week and intragastrically administrated with uricase inhibitor, potassium-oxonate (PO, 250 mg/kg), to induce hyperuricemia at the 8th week, once a day for 7 consecutive days, respectively (IB model). IB model plus CoTOL (0.4 ml/20g) and allopurinol (40 mg/kg) were administrated by gavage at the 5th week, once a day for 4 weeks. The feces and blood in each group were sampled at the 4th and 8th week. With no bacteria inoculation, CoTOL, allopurinol, and blank group were treated with CoTOL and allopurinol or water, respectively. 44 species of bacteria (i.e., Enterococcus faecalis, Streptococcus, etc.) genes were targeted by 6 ingredients of 6 herbs in CoTOL. Inoculation with Streptococcus faecalis significantly caused the elevation of uric acid and the change of intestinal flora structure, whereas treatment with CoTOL significantly increased the abundance of Akkermansia and those of Bacteroides and Alloprevotella decreased. Furthermore, CoTOL exhibited a unique effect on reducing weight unobserved in allopurinol intervention. The present study, for the first time, demonstrated that CoTOL has beneficial effects on hyperuricemia and overweight, which may be attributed to regulating material metabolism and improving the structure or function of intestinal flora. Thus, CoTOL may be a promising therapy for hyperuricemia and overweight in chronic gout management and can be integrated with conventional treatments.

Qu-Zhuo-Tong-Bi Decoction Alleviates Gouty Arthritis by Regulating Butyrate-Producing Bacteria in Mice.

Qu-zhuo-tong-bi decoction (QZTBD) is a traditional Chinese medicine prescription used to treat hyperuricemia and gout with no obvious adverse effects. However, the mechanism by which QZTBD treats gout has not been fully explored. Here, we investigated the effects of QZTBD on gouty arthritis and its therapeutic mechanism from the perspective of the gut microbiome. Our results demonstrated that QZTBD was effective for reducing serum uric acid level and attenuating paw edema and mechanical allodynia. QZTBD promoted the abundance of butyrate-producing bacteria and the production of SCFAs. Further study revealed that QZTBD restored the intestinal barrier function, modulated the expression of GPR43 and ABCG2, suppressed the activity of key glycolysis-related enzymes, and inhibited the generation of intestinal inflammatory factors. These findings suggested that QZTBD is an effective therapeutic drug for gouty arthritis. Butyrate-producing bacteria and its metabolites SCFAs might act as a potential target of QZTBD.

Combined effects of MSU crystals injection and high fat-diet feeding on the establishment of a gout model in C57BL/6 mice

Abstract Objective: Gout is characterized by inflammatory arthritis with hyperuricaemia and deposition of monosodium urate (MSU) crystals in the joints. Several animal models have been proposed based on MSU crystals injection or high-fat diet feeding; however, neither hyperuricaemia model nor acute gout model can effectively reflect clinical features of gout. This study aimed to assess the effectiveness of a compound gout model induced by the combination of MSU crystals injection and high-fat diet feeding. Methods: The compound gout model was induced by high-fat diet feeding per day and the intraplantar injection of MSU crystals (1 mg) into the footpad of each mouse every 10 days. Serum uric acid, foot swelling and pain analyses were performed at days 22, 32 and 42. Gout inflammation, serum proinflammatory cytokines and gut microbiota analyses were performed only at day 42. Results: Compared to hyperuricaemia model or acute gout model, the compound gout model showed little advantages of elevating serum uric acid, causing foot swelling and gout inflammation, while it caused more severe serum inflammation and gut microbiota dysbiosis. Severe serum inflammation in the compound gout model could be reflected by the increased levels of IL-1 α, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, IFN-γ, KC, MCP-1 and MIP-1β. In addition, the compound gout model induced more alterations in the gut microbiota, including increasing levels of Desulfovibrio and Parasutterella. Conclusion: The injection of MSU and feed of high-fat diet have a combined effect on elevating serum inflammation and causing gut microbiota disorders in the process of establishing a gout model.(AU)

Whole Genome Sequencing of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli Isolated From a Wastewater Treatment Plant in China.

BACKGROUND AND OBJECTIVES: Wastewater treatment plants (WWTPs) are one of the major reservoirs for antimicrobial resistant bacteria (ARB) and antimicrobial resistance genes (ARGs) in the environment. Thus, the investigation on ARB and ARGs from WWTPs has attracted increasing attention in recent years. In order to uncover the resistome in a WWTP treating effluents from a pharmaceutical industry in China, the extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains were isolated and their whole genome sequences were obtained and analyzed. Moreover, metagenomic sequencing was applied to give a comprehensive view of antibiotic resistance in this WWTP. METHODS: 18 ESBL-producing E. coli strains were isolated from a WWTP located in Taizhou, China on April, 2017. All strains were sequenced using Illumina HiSeq 2000 sequencer. The whole genome sequences were assembled using SPAdes software and annotated with RAST server. Sequence types (STs), plasmids, ARGs and virulence genes were predicted from the genomes using MLST, Plasmid Finder, ResFinder and Virulence Finder, respectively. Metagenomic DNA of the same sample was extracted and sequenced using Illumina Hiseq X Ten platform. Metagenomic sequences were assembled using SOAPdenovo software. RESULTS: All 18 ESBL-producing E. coli strains were resistant to ampicillin, cefazolin, and ceftriaxone. Analysis of their genomes revealed that all strains carried beta-lactamase encoding genes and the most prevalent type was bla CTX-M . Various virulence genes and ARGs confronting resistance to other types of antimicrobial agents were also predicted. Further investigation on the metagenomics data indicated 11 ARGs with high amino acid identities to the known ARGs. Five of these ARGs, aadA1, aac(6')-lb-cr, flo(R), sul2 and sul1, were also present in the genomes of the ESBL-producing E. coli isolated from the same sample. CONCLUSION: Our study revealed the resistome of a pharmaceutical WWTP by both culture-dependent and metegenomic methods. The existence of ESBL-producing E. coli strains, indicating that pharmaceutical WWTP can play a significant role in the emergence of ARB. The occurrence of ARGs annotated from the metagenomic data suggests that pharmaceutical WWTP can play a significant role in the emergence of ARGs. Our findings highlight the need for strengthening the active surveillance of ARB and ARGs from pharmaceutical industry.

3' Uridylation Confers miRNAs with Non-canonical Target Repertoires.

Many microRNAs (miRNAs) exist alongside abundant miRNA isoforms (isomiRs), most of which arise from post-maturation sequence modifications such as 3' uridylation. However, the ways in which these sequence modifications affect miRNA function remain poorly understood. Here, using human miR-27a in cell lines as a model, we discovered that a nonfunctional target site unable to base-pair extensively with the miRNA seed sequence can regain function when an upstream adenosine is able to base-pair with a post-transcriptionally added uridine in the miR-27a tail. This tail-U-mediated repression (TUMR) is abolished in cells lacking the uridylation enzymes TUT4 and TUT7, indicating that uridylation alters miRNA function by modulating target recognition. We identified a set of non-canonical targets in human cells that are specifically regulated by uridylated miR-27a. We provide evidence that TUMR expands the targets of other endogenous miRNAs. Our study reveals a function of uridylated isomiRs in regulating non-canonical miRNA targets.

Linderae radix ethanol extract attenuates alcoholic liver injury via attenuating inflammation and regulating gut microbiota in rats.

This study aimed to explore the influence of gut microbiota alterations induced by Linderae radix ethanol extract (LREE) on alcoholic liver disease (ALD) in rats and to study the anti-inflammatory effect of LREE on ALD through the lipopolysaccharide (LPS) toll-like receptor 4 (TLR4)-nuclear factor kappa B (NF-κB) pathway. ALD rat models were established by intragastric liquor [50% (v/v) ethanol] administration at 10 mL/kg body weight for 20 days. Rats were divided into six groups: normal group (no treatment), model group (ALD rats), Essentiale group (ALD rats fed with Essentiale, 137 mg/kg), and LREE high/moderate/low dose groups (ALD rats fed with 4, 2, or 1 g LREE/kg). NF-κB and LPS levels were evaluated. Liver pathological changes and intestinal ultrastructure were examined by hematoxylin and eosin staining and transmission electron microscopy. The gut microbiota composition was evaluated by 16S rDNA sequencing. Expression levels of TLR4 and CD68 in liver tissue, and occludin and claudin-1 in intestinal tissue were measured. LREE treatment significantly reduced NF-κB and LPS levels, improved liver pathological changes, and ameliorated intestinal ultrastructure injury. Meanwhile, LREE-fed groups showed a higher abundance of Firmicutes and a lower abundance of Bacteroidetes than the rats in the model group. Administration of LREE suppressed TLR4 overexpression and promoted the expression of occludin and claudin-1 in intestine tissue. Thus, LREE could partly ameliorate microflora dysbiosis, suppress the inflammatory response, and attenuate liver injury in ALD rats. The protective effect of LREE might be related to the LPS-TLR4-NF-κB pathway.

Alterations of the Gut Microbiota Associated With Promoting Efficacy of Prednisone by Bromofuranone in MRL/lpr Mice.

Gut microbiota played an important role in systemic lupus erythematosus (SLE) and glucocorticoids were prone to cause alterations in gut microbiota. This study addressed the effect of bromofuranone on the treatment of SLE with prednisone, since bromofuranone could regulate gut microbiota by inhibiting the AI-2/LuxS quorum-sensing. Remarkably, bromofuranone did not alleviate lupus but promoted the efficacy of prednisone in the treatment of lupus. The alterations in the gut microbiota, including decreased Mucispirillum, Oscillospira, Bilophila and Rikenella, and increased Anaerostipes, were associated with prednisone treatment for SLE. In addition, the increase of Lactobacillus, Allobaculum, Sutterella, and Adlercreutzia was positively associated with the bromofuranone-mediated promotion for the treatment of lupus. This was the first study demonstrating that the efficacy of glucocorticoids could be affected by the interventions in gut microbiota.

Structural Differences between Pri-miRNA Paralogs Promote Alternative Drosha Cleavage and Expand Target Repertoires.

MicroRNA (miRNA) processing begins with Drosha cleavage, the fidelity of which is critical for downstream processing and mature miRNA target specificity. To understand how pri-miRNA sequence and structure influence Drosha cleavage, we studied the maturation of three pri-miR-9 paralogs, which encode the same mature miRNA but differ in the surrounding scaffold. We show that pri-miR-9-1 has a unique Drosha cleavage profile due to its distorted and flexible stem structure. Cleavage of pri-miR-9-1, but not pri-miR-9-2 or pri-miR-9-3, generates an alternative miR-9 with a shifted seed sequence that expands the scope of its target RNAs. Analyses of low-grade glioma patient samples indicate that the alternative-miR-9 has a potential role in tumor progression. Furthermore, we provide evidence that distortion of pri-miRNA stems induced by asymmetric internal loops correlates with Drosha cleavage at non-canonical sites. Our studies reveal that pri-miRNA paralogs can have distinct functions via differential Drosha processing.

Linderae radix ethanol extract attenuates alcoholic liver injury via attenuating inflammation and regulating gut microbiota in rats

This study aimed to explore the influence of gut microbiota alterations induced by Linderae radix ethanol extract (LREE) on alcoholic liver disease (ALD) in rats and to study the anti-inflammatory effect of LREE on ALD through the lipopolysaccharide (LPS) toll-like receptor 4 (TLR4)-nuclear factor kappa B (NF-κB) pathway. ALD rat models were established by intragastric liquor [50% (v/v) ethanol] administration at 10 mL/kg body weight for 20 days. Rats were divided into six groups: normal group (no treatment), model group (ALD rats), Essentiale group (ALD rats fed with Essentiale, 137 mg/kg), and LREE high/moderate/low dose groups (ALD rats fed with 4, 2, or 1 g LREE/kg). NF-κB and LPS levels were evaluated. Liver pathological changes and intestinal ultrastructure were examined by hematoxylin and eosin staining and transmission electron microscopy. The gut microbiota composition was evaluated by 16S rDNA sequencing. Expression levels of TLR4 and CD68 in liver tissue, and occludin and claudin-1 in intestinal tissue were measured. LREE treatment significantly reduced NF-κB and LPS levels, improved liver pathological changes, and ameliorated intestinal ultrastructure injury. Meanwhile, LREE-fed groups showed a higher abundance of Firmicutes and a lower abundance of Bacteroidetes than the rats in the model group. Administration of LREE suppressed TLR4 overexpression and promoted the expression of occludin and claudin-1 in intestine tissue. Thus, LREE could partly ameliorate microflora dysbiosis, suppress the inflammatory response, and attenuate liver injury in ALD rats. The protective effect of LREE might be related to the LPS-TLR4-NF-κB pathway.