Activation of intestinal GR–FXR and PPARα–UGT signaling exacerbates ibuprofen-induced enteropathy in mice

Ibuprofen induces hepatic Cyp7a1 expression in mice via the intestinal FXR-FGF15 signaling

Non-steroidal anti-inflammatory drugs (NSAIDs) may cause drug-induced liver injury (DILI). However, the molecular mechanisms underlying NSAIDs hepatotoxicity remain elusive. Dysregulations of bile acids (BAs) have been implicated in various DILI. In this study, we systematically investigated the effects of ibuprofen, the most commonly used NSAID, on BA metabolism and signaling in adult male C57/BL6 mice after oral administration of ibuprofen (IBU) at clinically relevant doses (30, 100, and 200 mg/kg) for one week. Notably, IBU significantly decreased BA concentrations in the liver in a dose-dependent manner, with a concomitant increase in both mRNA and protein expression of cholesterol 7alpha-hydoxylase (CYP7A1), the rate-limiting enzyme for BA synthesis. Mechanically, IBU altered the composition of gut microbiota and increased cecal BAs, leading to reduced intestinal absorption of BAs and thus deactivated ileal farnesoid X receptor-fibroblast growth factor 15 (FXR-FGF15) signaling. Additionally, diclofenac and indomethacin also induced hepatic Cyp7a1 expression in mice via their effects on gut microbiota and intestinal BA signaling. To conclude, the current findings suggest that NSAIDs-induced liver injury could be at least partially attributable to the dysregulation of BA metabolism and signaling.

Activation of the YY1-UGT2B7 Axis Promotes Mammary Estrogen Homeostasis Dysregulation and Exacerbates Breast Tumor Metastasis

Metastasis is the most common pathway of cancer death. The lack of effective predictors of breast cancer metastasis is a pressing issue in clinical practice. Therefore, exploring the mechanism of breast cancer metastasis to uncover reliable predictors is very important for the clinical treatment of breast cancer patients. In this study, tandem mass tag quantitative proteomics technology was used to detect protein content in primary breast tumor tissue samples from patients with metastatic and nonmetastatic breast cancer at diagnosis. We found that the high expression of yin-yang 1(YY1) is strongly associated with poor prognosis in high-grade breast cancer. YY1 expression was detected in both clinical tumor tissue samples and tumor tissue samples from mammary-specific polyomavirus middle T antigen overexpression mouse model mice. We demonstrated that upregulation of YY1 expression was closely associated with breast cancer metastasis and that high YY1 expression could promote the migratory invasive ability of breast cancer cells. Mechanistically, YY1 directly binds to the UGT2B7 mRNA initiation sequence ATTCAT, thereby transcriptionally regulating the inhibition of UGT2B7 expression. UGT2B7 can regulate the development of breast cancer by regulating estrogen homeostasis in the breast, and the abnormal accumulation of estrogen, especially 4-OHE2, promotes the migration and invasion of breast cancer cells, ultimately causing the development of breast cancer metastasis. In conclusion, YY1 can regulate the UGT2B7-estrogen metabolic axis and induce disturbances in estrogen metabolism in breast tumors, ultimately leading to breast cancer metastasis. Disturbances in estrogen metabolism in the breast tissue may be an important risk factor for breast tumor progression and metastasis SIGNIFICANCE STATEMENT: In this study, we propose for the first time a regulatory relationship between YY1 and the UGT2B7/estrogen metabolism axis and explore the molecular mechanism. Our study shows that the YY1/UGT2B7/estrogen axis plays an important role in the development and metastasis of breast cancer. This study further elucidates the potential mechanisms of YY1-mediated breast cancer metastasis and the possibility and promise of YY1 as a predictor of cancer metastasis.

Microbiota and Mitochondrial Sex-Dependent Imbalance in Fibromyalgia: A Pilot Descriptive Study

Fibromyalgia is a widespread chronic condition characterized by pain and fatigue. Among the long list of physiological disturbances linked to this syndrome, mitochondrial imbalance and oxidative stress stand out. Recently, the crosstalk between mitochondria and intestinal microbiota has caught the attention of biomedical researchers, who have found connections between this axis and several inflammatory and pain-related conditions. Hence, this pilot descriptive study focused on characterizing the mitochondrial mass/mitophagy ratio and total antioxidant capacity in PBMCs, as well as some microbiota components in feces, from a Peruvian cohort of 19 females and 7 males with FM. Through Western blotting, electrochemical oxidation, ELISA, and real-time qPCR, we determined VDAC1 and MALPLC3B protein levels; total antioxidant capacity; secretory immunoglobulin A (sIgA) levels; and Firmicutes/Bacteroidetes, Bacteroides/Prevotella, and Roseburia/Eubacterium ratios; as well as Ruminococcus spp., Pseudomonas spp., and Akkermansia muciniphila levels, respectively. We found statistically significant differences in Ruminococcus spp. and Pseudomonas spp. levels between females and males, as well as a marked polarization in mitochondrial mass in both groups. Taken together, our results point to a mitochondrial imbalance in FM patients, as well as a sex-dependent difference in intestinal microbiota composition.

Interactions between NSAIDs, opioids and the gut microbiota - Future perspectives in the management of inflammation and pain

The composition of intestinal microbiota is influenced by a number of factors, including medications, which may have a substantial impact on host physiology. Nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics are among those widely used medications that have been shown to alter microbiota composition in both animals and humans. Although much effort has been devoted to identify microbiota signatures associated with these medications, much less is known about the underlying mechanisms. Mucosal inflammation, changes in intestinal motility, luminal pH and bile acid metabolism, or direct drug-induced inhibitory effect on bacterial growth are all potential contributors to NSAID- and opioid-induced dysbiosis, however, only a few studies have addressed directly these issues. In addition, there is a notable overlap between the microbiota signatures of these drugs and certain diseases in which they are used, such as spondyloarthritis (SpA), rheumatoid arthritis (RA) and neuropathic pain associated with type 2 diabetes (T2D). The aims of the present review are threefold. First, we aim to provide a comprehensive up-to-date summary on the bacterial alterations caused by NSAIDs and opioids. Second, we critically review the available data on the possible underlying mechanisms of dysbiosis. Third, we review the current knowledge on gut dysbiosis associated with SpA, RA and neuropathic pain in T2D, and highlight the similarities between them and those caused by NSAIDs and opioids. We posit that drug-induced dysbiosis may contribute to the persistence of these diseases, and may potentially limit the therapeutic effect of these medications by long-term use. In this context, we will review the available literature data on the effect of probiotic supplementation and fecal microbiota transplantation on the therapeutic efficacy of NSAIDs and opioids in these diseases.

The inhibition of tamoxifen on UGT2B gene expression and enzyme activity in rat liver contribute to the estrogen homeostasis dysregulation

Background

Tamoxifen treatment may induce dysregulation of estrogen homeostasis, leading to the occurrence of related adverse reactions. However, the potential mechanisms are still unclear. The purpose of the present study was to uncover whether tamoxifen treatment would act on estrogen metabolism-related biological enzymes and the regulatory effect on estrogen homeostasis to clarify the key factors and potential mechanisms of adverse reactions caused by long-term use of tamoxifen.

Method

Female SD rats were administrated with tamoxifen CMC-Na solution (p.o.) once daily for four weeks and then housed at room temperature. Serum, breast, liver, uterus, and ovarian tissues were obtained, and the effects of tamoxifen administration on estrogen homeostasis, the expression, and activity of estrogen metabolic enzyme were evaluated.

Results

Compared with the control group, the estrogen homeostasis was disturbed and the expression and activity of UGT2B1 (homology with human UGT2B7) were significantly reduced in the rats administrated with tamoxifen. The inhibitory effect of tamoxifen on UGT2B7 was dominated by hydrophobic and π-π stacking interactions, resulting in a concentration-dependent inhibition of UGT2B7 activity by tamoxifen and the imbalance of ligand-activated transcription factors, leading to abnormal regulation of UGT2B and disturbance of estrogen homeostasis, which in turn led to adverse reactions of tamoxifen.

Conclusion

We established links between estrogen metabolism and tamoxifen administration and we proposed that the UGT2B inhibition was involved in the disturbance of estrogen homeostasis and the occurrence of tamoxifen-related adverse reactions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-022-00574-6.

NSAID-Associated Small Intestinal Injury: An Overview From Animal Model Development to Pathogenesis, Treatment, and Prevention

With the wide application of non-steroidal anti-inflammatory drugs (NSAIDs), their gastrointestinal side effects are an urgent health burden. There are currently sound preventive measures for upper gastrointestinal injury, however, there is a lack of effective defense against lower gastrointestinal damage. According to a large number of previous animal experiments, a variety of NSAIDs have been demonstrated to induce small intestinal mucosal injury in vivo. This article reviews the descriptive data on the administration dose, administration method, mucosal injury site, and morphological characteristics of inflammatory sites of various NSAIDs. The cells, cytokines, receptors and ligands, pathways, enzyme inhibition, bacteria, enterohepatic circulation, oxidative stress, and other potential pathogenic factors involved in NSAID-associated enteropathy are also reviewed. We point out the limitations of drug modeling at this stage and are also pleased to discover the application prospects of chemically modified NSAIDs, dietary therapy, and many natural products against intestinal mucosal injury.

The Pathophysiology of Farnesoid X Receptor (FXR) in the GI Tract: Inflammation, Barrier Function and Innate Immunity

The Farnesoid-X Receptor, FXR, is a nuclear bile acid receptor. Its originally described function is in bile acid synthesis and regulation within the liver. More recently, however, FXR has been increasingly appreciated for its breadth of function and expression across multiple organ systems, including the intestine. While FXR’s role within the liver continues to be investigated, increasing literature indicates that FXR has important roles in responding to inflammation, maintaining intestinal epithelial barrier function, and regulating immunity within the gastrointestinal (GI) tract. Given the complicated and multi-factorial nature of intestinal barrier dysfunction, it is not surprising that FXR’s role appears equally complicated and not without conflicting data in different model systems. Recent work has suggested translational applications of FXR modulation in GI pathology; however, a better understanding of FXR physiology is necessary for these treatments to gain widespread use in human disease. This review aims to discuss current scientific work on the role of FXR within the GI tract, specifically in its role in intestinal inflammation, barrier function, and immune response, while also exploring areas of controversy.

Yinzhihuang Oral Liquid Ameliorates Hyperbilirubinemia Induced by δ-Aminolevulinic Acid and Novobiocin in Neonatal Rats

Yinzhihuang oral liquid (YZH) is a traditional Chinese medicine that has been widely used in Asia to prevent and treat neonatal hyperbilirubinemia, but the published preclinical studies on its anti-hyperbilirubinemia effect are conducted in adult animals, partly due to the lack of preclinical neonatal hyperbilirubinemia animal models. In the present study, we tested six reagents to induce hyperbilirubinemia in neonatal rats, and established two appropriate neonatal hyperbilirubinemia rat models by subcutaneous injection of δ-Aminolevulinic acid (ALA, 200 mg/kg) or novobiocin (NOVO, 200 mg/kg). Oral treatment of YZH (80, 160 and 320 mg/kg) significantly decreased serum conjugated bilirubin levels in ALA-treated neonatal rats and serum unconjugated bilirubin levels in NOVO-treated neonatal rats, respectively. Additionally, pre-treatment of YZH also prevented the increase of serum bilirubin levels in both ALA- and NOVO-treated rats. Mechanistically, YZH significantly up-regulated the mRNA expression of genes involved in hepatic bilirubin disposition (organic anion-transporting polypeptide 1b2, Oatp1b2; multidrug resistance-associated protein 2, Mrp2) and bilirubin conjugation (UDP-glucuronosyltransferase 1a1, Ugt1a1). Additionally, YZH up-regulated the mRNA expression of cytochrome P450 1A1 (Cyp1a1), the target gene of aryl hydrocarbon receptor (AhR), and increased the nuclear protein levels of AhR in livers of neonatal rats. YZH and its two active ingredients, namely baicalin (BCL) and 4'-hydroxyacetophenone (4-HT), up-regulated the mRNA expression of AhR target genes (CYP1A1 and UGT1A1) and increased nuclear protein levels of AhR in HepG2 cells. In conclusion, the present study provides two neonatal hyperbilirubinemia animal models and evaluates the anti-hyperbilirubinemia effect and mechanisms of YZH in neonatal animals.

The Nonsteroidal Anti-Inflammatory Drug Ketorolac Alters the Small Intestinal Microbiota and Bile Acids Without Inducing Intestinal Damage or Delaying Peristalsis in the Rat

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) induce significant damage to the small intestine, which is accompanied by changes in intestinal bacteria (dysbiosis) and bile acids. However, it is still a question of debate whether besides mucosal inflammation also other factors, such as direct antibacterial effects or delayed peristalsis, contribute to NSAID-induced dysbiosis. Here we aimed to assess whether ketorolac, an NSAID lacking direct effects on gut bacteria, has any significant impact on intestinal microbiota and bile acids in the absence of mucosal inflammation. We also addressed the possibility that ketorolac-induced bacterial and bile acid alterations are due to a delay in gastrointestinal (GI) transit. Methods: Vehicle or ketorolac (1, 3 and 10 mg/kg) were given to rats by oral gavage once daily for four weeks, and the severity of mucosal inflammation was evaluated macroscopically, histologically, and by measuring the levels of inflammatory proteins and claudin-1 in the distal jejunal tissue. The luminal amount of bile acids was measured by liquid chromatography-tandem mass spectrometry, whereas the composition of microbiota by sequencing of bacterial 16S rRNA. GI transit was assessed by the charcoal meal method. Results: Ketorolac up to 3 mg/kg did not cause any signs of mucosal damage to the small intestine. However, 3 mg/kg of ketorolac induced dysbiosis, which was characterized by a loss of families belonging to Firmicutes (Paenibacillaceae, Clostridiales Family XIII, Christensenellaceae) and bloom of Enterobacteriaceae. Ketorolac also changed the composition of small intestinal bile by decreasing the concentration of conjugated bile acids and by increasing the amount of hyodeoxycholic acid (HDCA). The level of conjugated bile acids correlated negatively with the abundance of Erysipelotrichaceae, Ruminococcaceae, Clostridiaceae 1, Muribaculaceae, Bacteroidaceae, Burkholderiaceae and Bifidobacteriaceae. Ketorolac, under the present experimental conditions, did not change the GI transit. Conclusion: This is the first demonstration that low-dose ketorolac disturbed the delicate balance between small intestinal bacteria and bile acids, despite having no significant effect on intestinal mucosal integrity and peristalsis. Other, yet unidentified, factors may contribute to ketorolac-induced dysbiosis and bile dysmetabolism.

A comprehensive time course and correlation analysis of indomethacin-induced inflammation, bile acid alterations and dysbiosis in the rat small intestine

It has been proposed that changes in microbiota due to nonsteroidal anti-inflammatory drugs (NSAIDs) alter the composition of bile, and elevation of hydrophobic secondary bile acids contributes to small intestinal damage. However, little is known about the effect of NSAIDs on small intestinal bile acids, and whether bile alterations correlate with mucosal injury and dysbiosis. Here we determined the ileal bile acid metabolome and microbiota 24, 48 and 72 h after indomethacin treatment, and their correlation with each other and with tissue damage in rats. In parallel with the development of inflammation, indomethacin increased the ileal proportion of glycine and taurine conjugated bile acids, but not bile hydrophobicity. Firmicutes decreased with time, whereas Gammaproteobacteria increased first, but declined later and were partially replaced by Bilophila, Bacteroides and Fusobacterium. Mucosal injury correlated negatively with unconjugated bile acids and Gram-positive bacteria, and positively with taurine conjugates and some Gram-negative taxa. Strong positive correlation was found between Lactobacillaceae, Ruminococcaceae, Clostridiaceae and unconjugated bile acids. Indomethacin-induced dysbiosis was not likely due to direct antibacterial effects or alterations in luminal pH. Here we provide the first detailed characterization of indomethacin-induced time-dependent alterations in small intestinal bile acid composition, and their associations with mucosal injury and dysbiosis. Our results suggest that increased bile hydrophobicity is not likely to contribute to indomethacin-induced small intestinal damage.

Sea Cucumber Sterol Alleviates the Lipid Accumulation in High-Fat-Fructose Diet Fed Mice

The effect of marine-derived sea cucumber sterol (SS) with a special sulfate group on lipid accumulation remains unknown, although phytosterol has been proved to have many biological activities, including lowering blood cholesterol. The purpose of the present study is to investigate the alleviation of SS on lipid accumulation and the possible underlying mechanism using high-fat-fructose diet fed mice. Dietary administration with SS for 8 weeks reduced significantly the body weight gain and lipid levels in serum and liver. Especially, SS was superior to phytosterol in lowering lipid accumulation due to the great promotion of fatty acid β-oxidation, the inhibition of cholesterol synthesis, and the acceleration of cholesterol efflux. The findings found that sea cucumber sterol exhibited a more significant effect than phytosterol on alleviating HFF-diet-induced lipid accumulation through regulating lipid and cholesterol metabolism, which might be attributed to the difference in the branch chain and sulfate group.

Intestinal Epithelial Cells-Derived Hypoxia-Inducible Factor-1α Is Essential for the Homeostasis of Intestinal Intraepithelial Lymphocytes

Hif-1α is a master regulator which involved in the transcriptional regulation of anti-inflammatory or cellular responding to hypoxia. Previous work shows that the absence of Hif-1α results in the destruction of intestinal epithelial cell (IEC) and abnormalities of intestinal barrier function. However, we know very little about other functions of Hif-1α on intestinal intraepithelial lymphocyte (IEL). Therefore, we generated a transgenic mouse (Hif1-α^ΔIEC mice), which was knocked out Hif1-α specifically in IECs, to study the effect of Hif1-α on IEL. IELs were isolated from the small intestine and colon of mice, respectively, and examined by flow cytometry and quantitative real-time PCR. All the cytokines expression was detected by quantitative real-time PCR. The NSAID enteropathy was induced by gavaged with 5 mg/kg indomethacin and the experimental colitis was induced by administration of 2.5% DSS. We found that the number of IELs is increased in Hif1-α ^ΔIEC mice. It is showed that knockout of Hif1-α in IECs led to significant changes in IEL phenotype, including a marked decline in the CD8αα⁺ and TCRγδ⁺ population. The reduction of CD8αα⁺ IELs is accompanied by increased apoptosis, decreased proliferation and weakened migration in Hif1-α^ΔIEC mice. Moreover, absence of intestinal epithelial Hif1-α markedly changed the population of IELs in NSAID-induced small intestinal injury and increased susceptibility to dextran sulfate sodium-induced colitis. In summary, our results first time demonstrate that IEC-derived Hif1-α is essential for maintaining IELs homeostasis and intestinal microbiota.