Profiling of ABC transporters during active ulcerative colitis and in vitro effect of inflammatory modulators

Elevated risk of adverse effects from foodborne contaminants and drugs in inflammatory bowel disease: a review

The global burden of Inflammatory bowel disease (IBD) has been rising over the last decades. IBD is an intestinal disorder with a complex and largely unknown etiology. The disease is characterized by a chronically inflamed gastrointestinal tract, with intermittent phases of exacerbation and remission. This compromised intestinal barrier can contribute to, enhance, or even enable the toxicity of drugs, food-borne chemicals and particulate matter. This review discusses whether the rising prevalence of IBD in our society warrants the consideration of IBD patients as a specific population group in toxicological safety assessment. Various in vivo, ex vivo and in vitro models are discussed that can simulate hallmarks of IBD and may be used to study the effects of prevalent intestinal inflammation on the hazards of these various toxicants. In conclusion, risk assessments based on healthy individuals may not sufficiently cover IBD patient safety and it is suggested to consider this susceptible subgroup of the population in future toxicological assessments.

Goat Milk Exosomes Ameliorate Ulcerative Colitis in Mice through Modulation of the Intestinal Barrier, Gut Microbiota, and Metabolites

Goat milk is rich in a variety of nutrients that are important for intestinal health and disease prevention. However, the role of exosomes in goat milk remains to be elucidated. This study investigated for the first time the therapeutic efficacy and molecular underlying mechanisms of mature milk exosomes (M-exo) and goat colostrum exosomes (C-exo) on dextran sodium sulfate-induced ulcerative colitis (UC) in mice. The findings demonstrate that M-exo and C-exo significantly improved physiological indices, suppressed the secretion of proinflammatory cytokines, and diminished oxidative stress and apoptosis in UC mice. Moreover, C-exo and M-exo restored the intestinal barrier function, remodeled the gut microbiota, and improved metabolite composition in the feces of colitis mice. In conclusion, goat milk exosomes ameliorate UC in mice, which provides a basis for the development of functional food applications for the prevention and treatment of inflammatory bowel disease.

Immune response caused by M1 macrophages elicits atrial fibrillation-like phenotypes in coculture model with isogenic hiPSC-derived cardiomyocytes

BACKGROUND

Atrial fibrillation has an estimated prevalence of 1.5-2%, making it the most common cardiac arrhythmia. The processes that cause and sustain the disease are still not completely understood. An association between atrial fibrillation and systemic, as well as local, inflammatory processes has been reported. However, the exact mechanisms underlying this association have not been established. While it is understood that inflammatory macrophages can influence cardiac electrophysiology, a direct, causative relationship to atrial fibrillation has not been described. This study investigated the pro-arrhythmic effects of activated M1 macrophages on human induced pluripotent stem cell (hiPSC)-derived atrial cardiomyocytes, to propose a mechanistic link between inflammation and atrial fibrillation.

METHODS

Two hiPSC lines from healthy individuals were differentiated to atrial cardiomyocytes and M1 macrophages and integrated in an isogenic, pacing-free, atrial fibrillation-like coculture model. Electrophysiology characteristics of cocultures were analysed for beat rate irregularity, electrogram amplitude and conduction velocity using multi electrode arrays. Cocultures were additionally treated using glucocorticoids to suppress M1 inflammation. Bulk RNA sequencing was performed on coculture-isolated atrial cardiomyocytes and compared to meta-analyses of atrial fibrillation patient transcriptomes.

RESULTS

Multi electrode array recordings revealed M1 to cause irregular beating and reduced electrogram amplitude. Conduction analysis further showed significantly lowered conduction homogeneity in M1 cocultures. Transcriptome sequencing revealed reduced expression of key cardiac genes such as SCN5A, KCNA5, ATP1A1, and GJA5 in the atrial cardiomyocytes. Meta-analysis of atrial fibrillation patient transcriptomes showed high correlation to the in vitro model. Treatment of the coculture with glucocorticoids showed reversal of phenotypes, including reduced beat irregularity, improved conduction, and reversed RNA expression profiles.

CONCLUSIONS

This study establishes a causal relationship between M1 activation and the development of subsequent atrial arrhythmia, documented as irregularity in spontaneous electrical activation in atrial cardiomyocytes cocultured with activated macrophages. Further, beat rate irregularity could be alleviated using glucocorticoids. Overall, these results point at macrophage-mediated inflammation as a potential AF induction mechanism and offer new targets for therapeutic development. The findings strongly support the relevance of the proposed hiPSC-derived coculture model and present it as a first of its kind disease model.

Inflammation alters the expression pattern of drug transporters during Caco-2 cell stimulation and azoxymethane-induced colon tumorigenesis

Drug transporters play a pivotal role in modulating drug disposition and are subject to alterations under inflammatory conditions. This study aimed to elucidate the intricate expression patterns of drug transporters during both acute and chronic inflammation, which are closely linked to malignant transformation. To investigate acute inflammation, we employed an in vitro model by subjecting Caco-2 cells to various inflammatory stimuli (IL-1β, TNF-α, or LPS) individually or in combination. The successful induction of inflammation was confirmed by robust increases in IL-6 and NO production. Notably, inflamed Caco-2 cells exhibited significantly diminished levels of ABCB1 and ABCG2, while the expression of ABCC2 was upregulated. For chronic inflammation induction in vivo, we employed the well-established AOM/DSS mouse model known for its association with colitis-driven tumorigenesis. Persistent inflammation was effectively monitored throughout the experiment via elevated IL-6 and NO levels. The sequential stages of tumorigenesis were confirmed through Ki-67 immunohistochemistry. Intriguingly, we observed gradual alterations in the expression patterns of the studied drug transporters during stepwise induction, with ABCB1, ABCG2, and ABCC1 showing downregulation and ABCC2 exhibiting upregulation. Immunohistochemistry further revealed dynamic changes in the expression of ABCB1 and ABCC2 during the induction cycles, closely paralleling the gradual increase in Ki-67 expression observed during the development of precancerous lesions. Collectively, our findings underscore the significant impact of inflammation on drug transporter expression, potentially influencing the process of malignant transformation of the colon.

Global regulation via modulation of ribosome pausing by the ABC-F protein EttA

Having multiple rounds of translation of the same mRNA creates dynamic complexities along with opportunities for regulation related to ribosome pausing and stalling at specific sequences. Yet, mechanisms controlling these critical processes and the principles guiding their evolution remain poorly understood. Through genetic, genomic, physiological, and biochemical approaches, we demonstrate that regulating ribosome pausing at specific amino acid sequences can produce ~2-fold changes in protein expression levels which strongly influence cell growth and therefore evolutionary fitness. We demonstrate, both in vivo and in vitro, that the ABC-F protein EttA directly controls the translation of mRNAs coding for a subset of enzymes in the tricarboxylic acid (TCA) cycle and its glyoxylate shunt, which modulates growth in some chemical environments. EttA also modulates expression of specific proteins involved in metabolically related physiological and stress-response pathways. These regulatory activities are mediated by EttA rescuing ribosomes paused at specific patterns of negatively charged residues within the first 30 amino acids of nascent proteins. We thus establish a unique global regulatory paradigm based on sequence-specific modulation of translational pausing.

Forsythiaside A attenuates lipopolysaccharide-induced mouse mastitis by activating autophagy and regulating gut microbiota and metabolism

Mastitis is an inflammatory disease of the mammary gland with a high incidence in lactating animals, significantly impacting their health and breastfeeding. Moreover, mastitis adversely affects milk quality and yield, resulting in substantial economic losses for the dairy farming industry. Forsythiaside A (FTA), a phenylethanol glycoside analog extracted from Forsythia, exhibits notable anti-inflammatory and antioxidant properties. However, its protective effects and specific mechanisms against mastitis remain unclear. In this study, a lipopolysaccharide (LPS)-induced mouse mastitis model was used to investigate the protective effect of FTA on LPS-induced mastitis and its potential mechanism using histological assays, Western blot, qRT-PCR, FITC-albumin permeability test, 16s rRNA gene sequencing analysis and non-targeted metabolomics assays to investigate the protective effect of FTA on LPS-induced mastitis model and its potential mechanism. The results demonstrated that FTA significantly mitigated LPS-induced mouse mastitis by reducing inflammation and apoptosis levels, modulating the PI3K/AKT/mTOR signaling pathways, inducing autophagy, and enhancing antioxidant capacity and the expression of tight junction proteins. Furthermore, FTA increased the abundance of beneficial microbiota while decreasing the levels of harmful microbiota in mice, thus counteracting the gut microbiota disruption induced by LPS stimulation. Intestinal metabolomics analysis revealed that FTA primarily regulated LPS-induced metabolite alterations through key metabolic pathways, such as tryptophan metabolism. This study confirms the anti-inflammatory and antioxidant effects of FTA on mouse mastitis, which are associated with key metabolic pathways, including the restoration of gut microbiota balance and the regulation of tryptophan metabolism. These findings provide a novel foundation for the treatment and prevention of mammalian mastitis using FTA.

RNA-seq transcriptome analysis provides new insights into the negative effects of tannic acid on the intestinal function of Brandt's voles (Lasiopodomys brandtii)

Tannic acid (TA), a significant plant secondary metabolite, is contained in the daily food of Brandt's voles. Its adverse effect on gut function has been shown in earlier research, but the underlying molecular mechanisms remain uncertain. In this study, male Brandt's vole (13 weeks old) were divided into two groups and given 0 (control) or 1,200 (TA-treated) mg•kg-1 TA for 18 days. Then RNA sequencing was used to conduct a thorough transcriptome analysis on the duodenum, jejunum, and ileum of Brandt's voles. Results showed that TA significantly increased serum total cholesterol concentration (P < 0.05) and decreased the nutrient digestibility (P < 0.05) of Brandt's voles. Furthermore, there were 174 differentially expressed genes (DEGs) in the duodenum, 96 DEGs in the jejunum, and 88 DEGs in the ileum between the control and TA-treated groups. Enrichment analysis revealed that many genes associated with bile secretion, fat digestion and absorption, innate immune response, and tight junction such as ABCG2, ABCG8, PEAK1, and IFR2, etc. were altered after TA treatment, which were verified by quantitative real-time PCR. These findings suggested that TA can change the expression of intestinal genes, thereby, altering nutrition metabolism and immunological function, eventually hindering the growth of Brandt's voles. The results of this study provide a theoretical basis for explaining how TA affects the gut function of Brandt's voles at the molecular level.

Gastrointestinal microbiota and metabolites possibly contribute to distinct pathogenicity of SARS-CoV-2 proto or its variants in rhesus monkeys

Gastrointestinal (GI) infection is evidenced with involvement in COVID-19 pathogenesis caused by SARS-CoV-2. However, the correlation between GI microbiota and the distinct pathogenicity of SARS-CoV-2 Proto and its emerging variants remains unclear. In this study, we aimed to determine if GI microbiota impacted COVID-19 pathogenesis and if the effect varied between SARS-CoV-2 Proto and its variants. We performed an integrative analysis of histopathology, microbiomics, and transcriptomics on the GI tract fragments from rhesus monkeys infected with SARS-CoV-2 proto or its variants. Based on the degree of pathological damage and microbiota profile in the GI tract, five of SARS-CoV-2 strains were classified into two distinct clusters, namely, the clusters of Alpha, Beta and Delta (ABD), and Proto and Omicron (PO). Notably, the abundance of potentially pathogenic microorganisms increased in ABD but not in the PO-infected rhesus monkeys. Specifically, the high abundance of UCG-002, UCG-005, and Treponema in ABD virus-infected animals positively correlated with interleukin, integrins, and antiviral genes. Overall, this study revealed that infection-induced alteration of GI microbiota and metabolites could increase the systemic burdens of inflammation or pathological injury in infected animals, especially in those infected with ABD viruses. Distinct GI microbiota and metabolite profiles may be responsible for the differential pathological phenotypes of PO and ABD virus-infected animals. These findings improve our understanding the roles of the GI microbiota in SARS-CoV-2 infection and provide important information for the precise prevention, control, and treatment of COVID-19.

N-Acetylglucosamine and its dimer ameliorate inflammation in murine colitis by strengthening the gut barrier function

Ulcerative colitis (UC) is a chronic gastrointestinal disease whose incidence is increasing rapidly worldwide. Anti-inflammatory medications, including 5-aminosalicylic acid (5-ASA), corticosteroids, and immunosuppressants, are used for its treatment; however, new alternatives would be required due to the serious side effects of some of these medications. N-Acetylglucosamine (NAG) is an amino sugar composed of mucin that is secreted by intestinal epithelial cells. It is also used to promote the growth of intestinal bacteria. The current study aimed to determine the efficacy of NAG against dextran sulfate sodium (DSS)-induced chronic colitis and elucidate its mechanism of action. Mice were randomly divided into control, DSS, 0.1% sulfasalazine, 0.1% NAG, 0.3% NAG, and 0.3% NAG-dimer (NAG-D) groups, and results showed that colitis-induced body weight loss, disease activity, colonic tissue damage, colon length shortening, and the loss of mucin-secreting area were significantly improved in the NAG-D group. The intestinal permeability indicator, serum CD 14 level, and expression of the tight junction protein, occludin, were both improved in the 0.3% NAG group. Inflammatory biomarkers, including GATA3, IFN-γ, p-IκBα, COX2, TGF-β1, and Smad7, were significantly lower in the 0.3% NAG and NAG-D groups than in the DSS group. The intestinal microbial composition was most significantly altered in the 0.3% NAG group, showing decreased ratios of pathogenic bacteria, such as Betaproteobacteria, especially Burkholderiales. The results overall suggested that NAG or NAG-D supplementation can alleviate inflammation by strengthening the intestinal barrier function and maintaining gut microbiota homeostasis in a DSS-induced colitis mouse model.

Comparative genetic, biochemical, and biophysical analyses of the four E. coli ABCF paralogs support distinct functions related to mRNA translation

Multiple paralogous ABCF ATPases are encoded in most genomes, but the physiological functions remain unknown for most of them. We herein compare the four Escherichia coli K12 ABCFs - EttA, Uup, YbiT, and YheS - using assays previously employed to demonstrate EttA gates the first step of polypeptide elongation on the ribosome dependent on ATP/ADP ratio. A Δ uup knockout, like Δ ettA , exhibits strongly reduced fitness when growth is restarted from long-term stationary phase, but neither Δ ybiT nor Δ yheS exhibits this phenotype. All four proteins nonetheless functionally interact with ribosomes based on in vitro translation and single-molecule fluorescence resonance energy transfer experiments employing variants harboring glutamate-to-glutamine active-site mutations (EQ ₂ ) that trap them in the ATP-bound conformation. These variants all strongly stabilize the same global conformational state of a ribosomal elongation complex harboring deacylated tRNA ^Val in the P site. However, EQ ₂ -Uup uniquely exchanges on/off the ribosome on a second timescale, while EQ ₂ -YheS-bound ribosomes uniquely sample alternative global conformations. At sub-micromolar concentrations, EQ ₂ -EttA and EQ ₂ -YbiT fully inhibit in vitro translation of an mRNA encoding luciferase, while EQ ₂ -Uup and EQ ₂ -YheS only partially inhibit it at ~10-fold higher concentrations. Moreover, tripeptide synthesis reactions are not inhibited by EQ ₂ -Uup or EQ ₂ -YheS, while EQ ₂ -YbiT inhibits synthesis of both peptide bonds and EQ ₂ -EttA specifically traps ribosomes after synthesis of the first peptide bond. These results support the four E. coli ABCF paralogs all having different activities on translating ribosomes, and they suggest that there remains a substantial amount of functionally uncharacterized "dark matter" involved in mRNA translation.

Integrated Microbiome and Metabolomic Analysis Reveal the Repair Mechanisms of Ovalbumin on the Intestine Barrier of Colitis Mice

The development and progression of colitis would detrimentally destroy the intestine barrier. However, there remains a paucity of evidence on whether ovalbumin (OVA) can be used as a nutritional food protein to repair the intestinal barrier. In this study, the repairing mechanism of OVA on intestinal barrier was thoroughly investigated by gut microbiota and untargeted metabolomics techniques. The findings demonstrated that OVA reduced intestinal permeability and restored mucin (0.75 ± 0.06) and tight junction (TJ) protein (0.67 ± 0.14) expression in colitis mice caused by 3% dextran sulfate sodium (DSS). In addition, the inflammation response and oxidative stress were also attenuated. The intake of OVA upregulated the abundance of Lactobacillaceae (7.60 ± 3.34%) and Akkermansiaceae (10.39 ± 5.97%). Furthermore, OVA upregulated the abundance of inosine (6.06 ± 0.36%), putrescine (4.14 ± 0.20%), and glycocholic acid (5.59 ± 0.23%) in colitis mice through ATP binding cassette (ABC) transporters and bile secretion pathways. In summary, our findings revealed that OVA could maintain intestinal health, which may provide crucial insights for preventing and treating intestinal diseases.

CXCR4 as possible druggable target linking inflammatory bowel disease and Parkinson's disease

Parkinson's disease (PD) is a chronic, progressive, and second most prevalent neurological disorder affecting the motor system. It has been found that people suffering with inflammatory bowel disease (IBD) are at 22% more risk for PD. In the current study, we have established a molecular link between gut and brain. The microarray gene expression datasets of Homo sapiens were obtained from Gene Expression Omnibus Database. Major genes involved in gut-brain connection were found to be CXCR4, LRRK2, APOE, SNCA, IL6, HIF-1α, ABCA1 etc. The common biological pathways linking both the pathologies were found to be HIF-signaling, cytokines interactions, JAK-STAT pathway, cholesterol metabolism, apoptosis and CXCR4 signaling which modulates the synaptic function and neuronal survival in the mature brain. It is known that flavonoid-rich foods throughout life hold the potential to limit the inflammation, neurodegeneration and, to prevent the age-dependent cognitive impairment. Therefore, the potential receptor, CXCR4 was used further for docking with twenty-seven phytochemicals from 5 different classes of Flavonoids found in several dietary items. Docking studies of the top scoring compounds were compared with a known inhibitor (BPRCX807) of receptor CXCR4 (IC₅₀ = 40.4 ± 8.0 nM). The study indicates that Flavan-3-ol families of flavonoids are the best fit and finest dietary supplements for improving brain health. Hence the food items like Pistachio nuts, hazelnuts, Green Tea, walnuts, etc. should be incorporated more in the diet of healthy people as well as in IBD and PD patients to prevent inflammation in gut and brain damage from oxidative stress.

The role of cholesterol and mitochondrial bioenergetics in activation of the inflammasome in IBD

Inflammatory Bowel Disease (IBD) is characterized by a loss of intestinal barrier function caused by an aberrant interaction between the immune response and the gut microbiota. In IBD, imbalance in cholesterol homeostasis and mitochondrial bioenergetics have been identified as essential events for activating the inflammasome-mediated response. Mitochondrial alterations, such as reduced respiratory complex activities and reduced production of tricarboxylic acid (TCA) cycle intermediates (e.g., citric acid, fumarate, isocitric acid, malate, pyruvate, and succinate) have been described in in vitro and clinical studies. Under inflammatory conditions, mitochondrial architecture in intestinal epithelial cells is dysmorphic, with cristae destruction and high dynamin-related protein 1 (DRP1)-dependent fission. Likewise, these alterations in mitochondrial morphology and bioenergetics promote metabolic shifts towards glycolysis and down-regulation of antioxidant Nuclear erythroid 2-related factor 2 (Nrf2)/Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) signaling. Although the mechanisms underlying the mitochondrial dysfunction during mucosal inflammation are not fully understood at present, metabolic intermediates and cholesterol may act as signals activating the NLRP3 inflammasome in IBD. Notably, dietary phytochemicals exhibit protective effects against cholesterol imbalance and mitochondrial function alterations to maintain gastrointestinal mucosal renewal in vitro and in vivo conditions. Here, we discuss the role of cholesterol and mitochondrial metabolism in IBD, highlighting the therapeutic potential of dietary phytochemicals, restoring intestinal metabolism and function.

Differential Transcriptomic Profiles Following Stimulation with Lipopolysaccharide in Intestinal Organoids from Dogs with Inflammatory Bowel Disease and Intestinal Mast Cell Tumor

Lipopolysaccharide (LPS) is associated with chronic intestinal inflammation and promotes intestinal cancer progression in the gut. While the interplay between LPS and intestinal immune cells has been well-characterized, little is known about LPS and the intestinal epithelium interactions. In this study, we explored the differential effects of LPS on proliferation and the transcriptome in 3D enteroids/colonoids obtained from dogs with naturally occurring gastrointestinal (GI) diseases including inflammatory bowel disease (IBD) and intestinal mast cell tumor. The study objective was to analyze the LPS-induced modulation of signaling pathways involving the intestinal epithelia and contributing to colorectal cancer development in the context of an inflammatory (IBD) or a tumor microenvironment. While LPS incubation resulted in a pro-cancer gene expression pattern and stimulated proliferation of IBD enteroids and colonoids, downregulation of several cancer-associated genes such as Gpatch4, SLC7A1, ATP13A2, and TEX45 was also observed in tumor enteroids. Genes participating in porphyrin metabolism (CP), nucleocytoplasmic transport (EEF1A1), arachidonic acid, and glutathione metabolism (GPX1) exhibited a similar pattern of altered expression between IBD enteroids and IBD colonoids following LPS stimulation. In contrast, genes involved in anion transport, transcription and translation, apoptotic processes, and regulation of adaptive immune responses showed the opposite expression patterns between IBD enteroids and colonoids following LPS treatment. In brief, the crosstalk between LPS/TLR4 signal transduction pathway and several metabolic pathways such as primary bile acid biosynthesis and secretion, peroxisome, renin-angiotensin system, glutathione metabolism, and arachidonic acid pathways may be important in driving chronic intestinal inflammation and intestinal carcinogenesis.

Retinal drusen counts are increased in inflammatory bowel disease, and with longer disease duration, more complications and associated IgA glomerulonephritis

Retinal drusen are deposits of inflammatory proteins that are found in macular degeneration and glomerulonephritis and result, in part, from complement activation. This was a cross-sectional observational study of individuals with inflammatory bowel disease (IBD) recruited from a Gastroenterology clinic who underwent non-mydriatic retinal photography. Deidentified images were examined for drusen, and drusen counts and size were compared with matched controls, and examined for clinical associations. The cohort with IBD comprised 19 individuals with ulcerative colitis, 41 with Crohn's disease and three with indeterminate colitis, including 34 males (54%) and an overall median age of 48 (IQR 23) years. Their median IBD duration was 7 (IQR 10) years, median CRP level was 7 (IQR 14) mg/L, and 28 (44%) had complications (fistula, stricture, bowel resection etc.), while 28 with Crohn's disease (68%) had colonic involvement. Drusen counts were higher in IBD than controls (12 ± 34, 3 ± 8 respectively, p = 0.04). Counts ≥ 10 were also more common (14, 22%, and 4, 6%, p = 0.02, OR 4.21, 95%CI 1.30 to 13.63), and associated with longer disease duration (p = 0.01, OR 1.06, 95%CI 1.00 to 1.13), an increased likelihood of complications (p = 0.003, OR 6.90, 95%CI 1.69 to 28.15) and higher CRP levels at recruitment (p = 0.008, OR1.02, 95%CI 1.00 to 1.05). Increased retinal drusen were found in all four individuals with Crohn's disease and IgA glomerulonephritis. IBD and drusen may share pathogenetic mechanisms and underlying risk factors such as complement activation.

Research advances in the role and pharmaceuticals of ATP-binding cassette transporters in autoimmune diseases

Autoimmune diseases are caused by the immune response of the body to its antigens, resulting in tissue damage. The pathogenesis of these diseases has not yet been elucidated. Most autoimmune diseases cannot be cured by effective drugs. The treatment strategy is to relieve the symptoms of the disease and balance the body's autoimmune function. The abnormal expression of ATP-binding cassette (ABC) transporters is directly related to the pathogenesis of autoimmune diseases and drug therapy resistance, which poses a great challenge for the drug therapy of autoimmune diseases. Therefore, this paper reviews the interplay between ABC transporters and the pathogenesis of autoimmune diseases to provide research progress and new ideas for the development of drugs in autoimmune diseases.

Level and change in bone microarchitectural parameters and their relationship with previous fracture and established bone mineral density loci

BACKGROUND

Osteoporosis is characterised by a reduction of bone mineral density (BMD) and predisposition to fracture. Bone microarchitecture, measured by high resolution peripheral quantitative computed tomography (HR-pQCT), has been related to fragility fractures and BMD and has been the subject of large-scale genome-wide analysis. We investigated whether fracture was related to baseline values and longitudinal changes in bone microarchitecture and whether bone microarchitecture was associated with established BMD loci.

METHODS

115 males and 99 females (aged 72-81 at baseline) from the Hertfordshire Cohort Study (HCS) were analysed. Fracture history was determined in 2011-2012 by self-report and vertebral fracture assessment. Participants underwent HR-pQCT scans of the distal radius and tibia in 2011-2012 and 2017. Previous fracture in relation to baseline values and changes in tibial HR-pQCT parameters was examined using sex-adjusted logistic regression with and without adjustment for age, sociodemographic, lifestyle and clinical characteristics; baseline values and changes in parameters associated with previous fracture were then examined in relation to four established BMD loci after adjustment for sex and age.

RESULTS

Previous fracture was related to: higher trabecular area (fully-adjusted odds ratio [95% CI] per SD greater baseline value: 2.18 [1.27,3.73], p = 0.005); lower total volumetric BMD (0.53 [0.34,0.84], p = 0.007), cortical area (0.53 [0.30,0.95], p = 0.032), cortical BMD (0.56 [0.36,0.88], p = 0.011) and cortical thickness (0.45 [0.27,0.77], p = 0.004); and greater declines in trabecular BMD (p = 0.001). Associations were robust in sex- and fully-adjusted analysis. Relationships between BMD loci and these HR-pQCT parameters were weak: rs3801387 (WNT16) was related to decline in trabecular BMD (p = 0.011) but no other associations were significant (p > 0.05).

CONCLUSION

Baseline values of HR-pQCT parameters and greater decline in trabecular BMD were associated with fracture. Change in trabecular BMD was associated with WNT16 which has been demonstrated to influence bone health in murine models and human genome-wide association studies (GWAS).

Roles of Multidrug Resistance Protein 4 in Microbial Infections and Inflammatory Diseases

Numerous studies have reported the emergence of antimicrobial resistance during the treatment of common infections. Multidrug resistance (MDR) leads to failure of antimicrobial treatment, prolonged illness, and increased morbidity and mortality. Overexpression of multidrug resistance proteins (MRPs) as drug efflux pumps are one of the main contributions of MDR, especially multidrug resistance protein 4 (MRP4/ABCC4) in the development of antimicrobial resistance. The molecular mechanism of antimicrobial resistance is still under investigation. Various intervention strategies have been developed for overcoming MDR, but the effect is limited. Suppression of MRP4 may be an attractive therapeutic approach for addressing drug resistance. However, there are few reports on the involvement of MRP4 in antimicrobial resistance and inflammatory diseases. In this review, we introduced the function and regulation of MRP4, and then summarized the roles of MRP4 in microbial infections and inflammatory diseases as well as polymorphisms in the gene encoding this transporter. Further studies should be conducted on drug therapy targeting MRP4 to improve the efficacy of antimicrobial therapy. This review can provide useful information on MRP4 for overcoming antimicrobial resistance and anti-inflammatory therapy.

Sudachinoid- and Ichangensin-Type Limonoids from Citrus junos Downregulate Pro-Inflammatory Cytokines

Limonoids, a dominant group of phytochemicals in the Rutaceae family, are known to exhibit several pharmacological activities. To identify natural products having efficacy against inflammatory bowel disease (IBD), we isolated 13 limonoids including a new compound, methyl sudachinoid A, from the seeds of Citrus junos and investigated their anti-inflammatory effects by assessing the expression of pro-inflammatory cytokines in lipopolysaccharide-stimulated RAW 264.7 mouse macrophages and HT-29 human colon epithelial cells. Our findings revealed that limonoids significantly downregulated the pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, and nuclear transcription factor κB. In particular, sudachinoid-type compounds, methyl sudachinoid A and sudachinoid B, and ichangensin-type compound, 1-O-methyichangensin downregulated the expression of pro-inflammatory cytokines more potently than other limonoids, nomilin and limonin, which have been previously reported to exhibit anti-inflammatory activities in other cells; nomilin and limonin were therefore employed as positive controls in this study. Herein, we reveal that the anti-inflammatory activities of limonoids including a new compound methyl sudachinoid A from C. junos were mediated via the downregulation of pro-inflammatory cytokines and these limonoids can be employed as potential therapeutic phytochemicals for IBD.

Chorioamnionitis Induces a Specific Signature of Placental ABC Transporters Associated with an Increase of miR-331-5p in the Human Preterm Placenta

Background/Aims

The ATP-binding cassette (ABC) transporters mediate drug biodisposition and immunological responses in the placental barrier. In vitro infective challenges alter expression of specific placental ABC transporters. We hypothesized that chorioamnionitis induces a distinct pattern of ABC transporter expression.

Methods

Gene expression of 50 ABC transporters was assessed using TaqMan® Human ABC Transporter Array, in preterm human placentas without (PTD; n=6) or with histological chorioamnionitis (PTDC; n=6). Validation was performed using qPCR, immunohistochemistry and Western blot. MicroRNAs known to regulate P-glycoprotein (P-gp) were examined by qPCR.

Results

Up-regulation of ABCB9, ABCC2 and ABCF2 mRNA was detected in chorioamnionitis (p<0.05), whereas placental ABCB1 (P-gp; p=0.051) and ABCG2 (breast cancer resistance protein-BCRP) mRNA levels (p=0.055) approached near significant up-regulation. In most cases, the magnitude of the effect significantly correlated to the severity of inflammation. Upon validation, increased placental ABCB1 and ABCG2 mRNA levels (p<0.05) were observed. At the level of immunohistochemistry, while BCRP was increased (p<0.05), P-gp staining intensity was significantly decreased (p<0.05) in PTDC. miR-331-5p, involved in P-gp suppression, was upregulated in PTDC (p<0.01) and correlated to the grade of chorioamnionitis (p<0.01).

Conclusions

Alterations in the expression of ABC transporters will likely lead to modified transport of clinically relevant compounds at the inflamed placenta. A better understanding of the potential role of these transporters in the events surrounding PTD may also enable new strategies to be developed for prevention and treatment of PTD.

Hispidulin-7-O-Neohesperidoside from Cirsium japonicum var. ussuriense Attenuates the Production of Inflammatory Mediators in LPS-Induced Raw 264.7 Cells and HT-29 Cells

Background:

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and involves secretion of inflammatory mediators. The flavone diglycoside hispidulin-7-O-neohesperidoside (HN) isolated from the methanolic extract of aerial parts of Cirsium japonicum var. ussuriense, but its pharmacologic activities, with the exception of alleviation of alcohol toxicity, have not been investigated to date.

Objective:

The aim of the present study was to investigate the anti-inflammatory activities of HN for the treatment of chronic inflammatory illnesses, including IBD.

Materials and Methods:

In lipopolysaccharide (LPS)-induced RAW264.7 cells and HT-29 cells, the effects of HN on cell viability and nitric oxide (NO) production were examined via MTT assay and the Griess reaction, respectively. The expression levels of interleukin (IL)-1α, IL-8, and tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS) protein levels were measured by enzyme-linked immunosorbent assay and Western blotting, respectively.

Results:

HN concentration-dependently inhibited NO production in LPS-induced RAW 264.7 cells. Treatment with HN considerably downregulated the levels of the pro-inflammatory cytokines, IL-1β and TNF-α and the iNOS protein level in LPS-induced RAW 264.7 cells. Furthermore, HN inhibited the production of the chemotactic cytokine, IL-8, in LPS-induced HT-29 cells.

Conclusion:

HN has potential as an anti-inflammatory agent to prevent and/or treat IBD.

SUMMARY

Hispidulin-7-O-neohesperidoside (HN) is flavone diglycoside isolated from the methanolic extract of aerial parts of Cirsium japonicum var. ussuriense.

HN concentration-dependently inhibited NO production and considerably downregulated the levels of the proinflammatory cytokines, IL-1β and TNF-α, and the iNOS protein level in LPS-induced RAW 264.7 cells.

HN inhibited the production of the chemotactic cytokine, IL-8, in LPS-induced HT-29 cells.

HN has potential as an anti-inflammatory agent to prevent and/or treat IBD.

Abbreviations used: IBD: Inflammatory bowel disease, HN: hispidulin-7-O-neohesperidoside, LPS: lipopolysaccharide, NO: nitric oxide, IL: interleukin, TNF: tumor necrosis factor, iNOS: inducible nitric oxide synthase, CD: Crohn's disease, UC: ulcerative colitis, RT: room temperature, DMEM: Dulbecco's modified Eagle's medium, FBS: fetal bovine serum, PBS: phosphate buffered saline, SDS: sodium dodecyl sulfate, PVDF: polyvinylidene difluoride, SD: standard deviation

Common links between metabolic syndrome and inflammatory bowel disease: Current overview and future perspectives

Metabolic syndrome (MS) features a constellation of central obesity, dyslipidemia, impaired glucose metabolism and often hypertension joined by insulin resistance and chronic inflammation. All these elements greatly raise patient's risk of cardiovascular disease and type 2 diabetes, resulting in an increased mortality. Metabolic syndrome affects approximately 20-25% of the world's adult population and thus it is essential to study its pathophysiology and seek new pharmacological targets. There is a thoroughly studied link between MS and inflammatory diseases of the gastrointestinal (GI) system, i.e. steatohepatitis. However, recent findings also indicate similarities in pathophysiological features between MS and inflammatory bowel disease (IBD), including adipose tissue dysregulation, inadequate immune response, and inflammation. In this review we aim to outline the pathophysiology of MS and emphasize the aspects revealed recently, such as mineralocorticoid activity, involvement of sex hormones and an accompanying increase in prolactin secretion. More importantly, we focus on the common links between MS and IBD. Finally, we describe new strategies and drug targets that may be utilized in MS therapy, namely adiponectin mimetics, GLP-1-based multi agonists, ABCA1 agonists and possible role of miRNA. We also discuss the possible utility of selected agents as adjuvants in IBD therapy.