Tauroursodeoxycholic Acid Reverses Dextran Sulfate Sodium-Induced Colitis in Mice via Modulation of Intestinal Barrier Dysfunction and Microbiome Dysregulation.

Ulcerative colitis (UC) is an immune-mediated inflammatory disease that can lead to persistent damage and even cancer without any intervention. Conventional treatments can alleviate UC symptoms but are costly and cause various side effects. Tauroursodeoxycholic acid (TUDCA), a secondary bile acid derivative, possesses anti-inflammatory and cytoprotective properties for various diseases, but its potential therapeutic benefits in UC have not been fully explored. Mice were subjected to colitis induction using 3% dextran sulfate sodium (DSS). The therapeutic effect of TUDCA was evaluated by body weight loss, disease activity index (DAI), colon length, and spleen weight ratio. Tissue pathology was assessed using H&E staining, while the levels of pro-inflammatory and anti-inflammatory cytokines in colonic tissue were quantified via ELISA. Tight junction proteins were detected by immunoblotting and intestinal permeability was assessed using fluorescein isothiocyanate (FITC)-dextran. Moreover, the gut microbiota was profiled using high-throughput sequencing of the 16S rDNA gene. TUDCA alleviated the colitis in mice, involving reduced DAI, attenuated colon and spleen enlargement, ameliorated histopathological lesions, and normalized levels of pro-inflammatory and anti-inflammatory cytokines. Furthermore, TUDCA treatment inhibited the downregulation of intestinal barrier proteins, including zonula occludens-1 and occludin, thus reducing intestinal permeability. The analysis of gut microbiota suggested that TUDCA modulated the dysbiosis in mice with colitis, especially for the remarkable rise in Akkermansia TUDCA exerted a therapeutic efficacy in DSS-induced colitis by reducing intestinal inflammation, protecting intestinal barrier integrity, and restoring gut microbiota balance. SIGNIFICANCE STATEMENT: This study demonstrates the potential therapeutic benefits of Tauroursodeoxycholic acid (TUDCA) in ulcerative colitis. TUDCA effectively alleviated colitis symptoms in mice, including reducing inflammation, restoring intestinal barrier integrity and the dysbiosis of gut microbiota. This work highlights the promising role of TUDCA as a potentially alternative treatment, offering new insights into managing this debilitating condition.

A mannitol-modified emodin nano-drug restores the intestinal barrier function and alleviates inflammation in a mouse model of DSS-induced ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory disease of the colon that is characterized by mucosal ulcers. Given its increasing prevalence worldwide, it is imperative to develop safe and effective drugs for treating UC. Emodin, a natural anthraquinone derivative present in various medicinal herbs, has demonstrated therapeutic effects against UC. However, low bioavailability due to poor water solubility limits its clinical applications. METHODS: Emodin-borate nanoparticles (EmB) were synthesized to improve drug solubility, and they modified with oligomeric mannitol into microgels (EmB-MO) for targeted delivery to intestinal macrophages that express mannose receptors. UC was induced in a mouse model using dextran sulfate sodium (DSS), and different drug formulations were administered to the mice via drinking water. The levels of inflammation-related factors in the colon tissues and fecal matter were measured using enzyme-linked immunosorbent assay. Intestinal permeability was evaluated using fluorescein isothiocyanate dextran. HE staining, in vivo imaging, real-time PCR, and western blotting were performed to assess intestinal barrier dysfunction. RESULTS: Both EmB and EmB-MO markedly alleviated the symptoms of UC, including body weight loss, stool inconsistency, and bloody stools and restored the levels of pro- and anti-inflammatory cytokines. However, the therapeutic effects of EmB-MO on the macroscopic and immunological indices were stronger than those of EmB and similar to those of 5-aminosalicylic acid. Furthermore, EmB-MO selectively accumulated in the inflamed colon epithelium and restored the levels of the gut barrier proteins such as ZO-1 and Occludin. CONCLUSIONS: EmB-MO encapsulation significantly improved water solubility, which translated to greater therapeutic effects on the immune balance and gut barrier function in mice with DSS-induced UC. Our findings provide novel insights into developing emodin-derived drugs for the management of UC.

Functional metabolomics revealed the dual-activation of cAMP-AMP axis is a novel therapeutic target of pancreatic cancer.

Pancreatic cancer (PC) is one of the most malignant cancers, owing to extremely high aggressiveness and mortality. Yet, this condition currently incurs widely drug resistance and therapeutic deficiency. In this study, we proposed a novel functional metabolomics strategy as Spatial Temporal Operative Real Metabolomics (STORM) to identify the determinant functional metabolites in a dynamic and visualized pattern whose level changes are mechanistically associated with therapeutic efficiency of gemcitabine against PC. Integrating quantitative analysis and spatial-visualization characterization of functional metabolites in vivo, we identified that the AMP-cAMP axis was a novel therapeutic target of PC to intermediate therapeutic efficiency of gemcitabine. Gemcitabine could induce the dual accumulation of cyclic AMP (cAMP) and AMP in tumor tissues. Quantitative analysis of associated biosynthetic enzymes and genes revealed that two independent intracellular ATP derived biosynthetic pathways to promote the dual activation of AMP-cAMP axis in a lower-level energetic environment. Then, gemcitabine induced the dual accumulation of AMP and cAMP can separately activate signaling pathways of AMPK and PKA, leading to the inhibition of tumor growth by the upregulation of the downstream tumor suppressor GADD45A. Collectively, our new STORM strategy was the first time to identify novel target of PC from a metabolic perspective as the dual activation of AMP-cAMP axis induced by gemcitabine can efficiently suppress PC tumor growth. In addition, such discovery has the capability to lower drug resistance of gemcitabine by specifically interacting with novel target, contributing to the improvement of therapeutic efficiency.

Effective extraction of fluoroquinolones from water using facile modified plant fibers.

In this study, ecofriendly and economic carboxy-terminated plant fibers (PFs) were used as adsorbents for the effective in-syringe solid phase extraction (IS-SPE) of fluoroquinolone (FQ) residues from water. Based on the thermal esterification and etherification reaction of cellulose hydroxy with citric acid (CA) and sodium chloroacetate in aqueous solutions, carboxy groups grafted onto cotton, cattail, and corncob fibers were fabricated. Compared with carboxy-terminated corncob and cotton, CA-modified cattail with more carboxy groups showed excellent adsorption capacity for FQs. The modified cattail fibers were reproducible and reusable with relative standard deviations of 3.2%-4.2% within 10 cycles of adsorption-desorption. A good extraction efficiency of 71.3%-80.9% was achieved after optimizing the extraction condition. Based on carboxylated cattail, IS-SPE coupled with ultra-performance liquid chromatography with a photodiode array detector was conducted to analyze FQs in environmental water samples. High sensitivity with limit of detections of 0.08-0.25 µg/L and good accuracy with recoveries of 83.8%-111.7% were obtained. Overall, the simple and environment-friendly modified waste PFs have potential applications in the effective extraction and detection of FQs in natural waters.

Ferric iron loaded porphyrinic zirconium MOFs on corncob for the enhancement of diuretics extraction.

Herein, corncob waste was used as a scaffold for the fabrication of effective adsorbents. Porphyrinic zirconium metal-organic frameworks (MOFs) PCN-223 and PCN-224 constructed by different numbers of Zr6 cluster nodes were grown on the surface of the corncob. Fe (Ш) ions were implanted in the porphyrin ring by post-synthesis modification. The results showed that the extraction capacity of diuretics on PCN-224@corncob containing suitable pore size was larger than that of PCN-223@corncob. The adsorption of diuretics was further enhanced because of the electrostatic effect caused by implantation of Fe (Ш) ions. PCN-224-Fe@corncob was recyclable and selective for the extraction of furosemide (Fur) and bumetanide (Bum). Coupled in-syringe solid phase extraction (IS-SPE) with ultra-performance liquid chromatography (UPLC), an efficient, sensitive, and stable method was established. With a sensitivity between 0.6 and 1.0 µg/L and a recovery between 83.2% and 119.2%, it is used for the analysis of trace amounts of Fur and Bum in weight loss products and environmental water. The functionalized corncob has potential application for the adsorption of diuretics, and the metal ions implantation in MOFs provides a promising strategy for enhancing extraction capacity.

Emerging pharmacotherapy for inflammatory bowel diseases.

Inflammatory bowel disease (IBD) refers to a gamut of disorders that are characterized by chronic intestinal inflammation, including ulcerative colitis (UC) and Crohn's disease (CD), which often leads to mucosal ulceration and progressive loss of intestinal function. The etiopathogenesis of IBD has not been completely clarified, although multiple factors involving genetic modifications, host immune dysfunction, intestinal dysbiosis and environmental effects have been implicated. Currently, pharmacotherapies including both non-targeted and targeted biological agents are widely used for the clinical treatment of IBD. In addition, novel therapeutic approaches that target the intestinal microorganisms, such as fecal microbiota transplantation, antibiotics, probiotics and microbial metabolite inhibitors, are also under development. However, these treatments are either accompanied by side effects or cannot achieve complete clinical remission when used alone. The efficacy and safety of drugs are currently a clinical challenge. Thus, advanced drug delivery systems are needed for targeted delivery of drugs to the inflammatory sites and avoid absorption by healthy tissues. In this review, we have summarized the latest research on the pathogenesis of IBD and the emerging pharmacotherapies, and discussed potential therapeutic targets for innovative therapies.

Hyaluronic Acid-Melatonin Nanoparticles Improve the Dysregulated Intestinal Barrier, Microbiome and Immune Response in Mice with Dextran Sodium Sulfate-Induced Colitis.

Although the cause of inflammatory bowel disease (IBD) is unclear, current studies have found that the main factors involved in its pathogenesis include imbalance of mucosal immune response, intestinal dysbiosis, and destruction of the intestinal barrier. We synthesized an amphiphilic conjugate of hyaluronic acid (HA) and melatonin (MT), which have established immunomodulatory and antioxidant properties, by stimulating their nano-aggregation. Inducing colitis by dextran sodium sulfate (DSS), HA-MT accumulated in the inflamed colon epithelium of colitis mice, and markedly improved the colitis symptoms, repaired the damaged intestinal barrier and inhibited colon inflammation. In addition, through bacterial 16S rDNA sequencing, it was found that HA-MT can restore the ratio of Firmicutes/Bacteroidetes by increasing the overall microbial richness and diversity, and alleviate the intestinal dysbiosis of mice with colitis. In the analysis of the intestinal flora at the species level, the abundance of Lactobacillus increased in colitis mice treated with HA-MT while that of Bacteroides, Blautia and Streptococcus decreased in the colitis mice treated with HA-MT. Our findings suggest that the HA-MT system is a promising prebiotic, which can relieve the symptoms of IBD by regulating the intestinal microflora and restoring intestinal homeostasis, inhibiting inflammation.

The Novel Interplay between Commensal Gut Bacteria and Metabolites in Diet-Induced Hyperlipidemic Rats Treated with Simvastatin.

Hyperlipidemia is one kind of metabolic syndrome for which the treatment commonly includes simvastatin (SV). Individuals vary widely in statin responses, and growing evidence implicates gut microbiome involvement in this variability. However, the associated molecular mechanisms between metabolic improvement and microbiota composition following SV treatment are still not fully understood. In this study, combinatory approaches using ultrahigh-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF MS/MS)-based metabolomic profiling, PCR-denaturing gradient gel electrophoresis (PCR-DGGE), quantitative PCR (qPCR), and 16S rRNA gene sequencing-based gut microbiota profiling were performed to investigate the interplay of endogenous metabolites and the gut microbiota related to SV treatment. A total of 6 key differential endogenous metabolites were identified that affect the metabolism of amino acids (phenylalanine and tyrosine), unsaturated fatty acids (linoleic acid and 9-hydroxyoctadecadienoic acid (9-HODE)), and the functions of gut microbial metabolism. Moreover, a total of 22 differentially abundant taxa were obtained following SV treatment. Three bacterial taxa were identified to be involved in SV treatment, namely, Bacteroidaceae, Prevotellaceae, and Porphyromonadaceae. These findings suggested that the phenylalanine and tyrosine-associated amino acid metabolism pathways, as well as the linoleic acid and 9-HODE-associated unsaturated fatty acid metabolism pathways, which are involved in gut flora interactions, might be potential therapeutic targets for improvement in SV hypolipidemic efficacy. The mass spectrometric data have been deposited to MassIVE (https://massive.ucsd.edu/ProteoSAFe/static/massive.jsp). Username: MSV000087842_reviewer. Password: hardworkingzsr.

Dihydromyricetin improves DSS-induced colitis in mice via modulation of fecal-bacteria-related bile acid metabolism.

Recent studies show that the nutraceutical supplement dihydromyricetin (DHM) can alleviate IBD in murine models by downregulating the inflammatory pathways. However, the molecular mechanistic link between the therapeutic efficiency of DHM, gut microbiota, and the metabolism of microbial BAs remains elusive. In this study, we explored the improvement of DHM on the dysregulated gut microbiota of mice with dextran sulfate sodium (DSS)-induced colitis. We found that DHM could markedly improve colitis symptoms, gut barrier disruption, and colonic inflammation in DSS-treated mice. In addition, bacterial 16S rDNA sequencing assay demonstrated that DHM could alleviate gut dysbiosis in mice with colitis. Furthermore, antibiotic-mediated depletion of the gut microflora and fecal microbiome transplantation (FMT) demonstrated that the therapeutic efficiency of DHM was closely associated with gut microbiota. BA-targeted metabolomics analysis revealed that DHM restored the metabolism of microbial BAs in the gastrointestinal tract during the development of colitis. DHM significantly enriched the proportion of the beneficial Lactobacillus and Akkermansia genera, which were correlated with increased gastrointestinal levels of unconjugated BAs involving chenodeoxycholic acid and lithocholic acid, enabling the BAs to activate specific receptors, such as FXR and TGR5, and maintaining intestinal integrity. Taken together, DHM could alleviate DSS-induced colitis in mice by restoring the dysregulated gut microbiota and BA metabolism, leading to improvements in intestinal barrier function and colonic inflammation. Increased microbiota-BAs-FXR/TGR5 signaling may be the potential targets of DHM in colitis. Therefore, our findings provide novel insights into the development of novel DHM-derived drugs for the management of IBD.

Metal-organic framework grafted with melamine for the selective recognition and miniaturized solid phase extraction of aristolochic acid â from traditional Chinese medicine.

Aristolochic acid Ⅰ is a nephrotoxic compound and exist in some traditional Chinese medicines at trace level. Up to now, specific enrichment of aristolochic acid Ⅰ remains important procedure and key problem in its analysis. In this study, melamine was proposed as the recognition unit and grafted on the surface of metal-organic framework to fabricate a specific material for aristolochic acid Ⅰ. This material was prepared by using a two-step strategy and the preparation process was optimized. The physical and chemical properties were investigated using scanning electron microscopy, Fourier-transfer infrared spectroscopy, X-ray diffraction and nitrogen adsorption-desorption techniques. Adsorption properties were evaluated by binding experiments. The melamine modified material exhibited a uniform morphology, high specific surface area (460.20 m2 g-1), high adsorption capacity (25.57 mg g-1), fast mass transfer rate and excellent selectivity. Further, a specific and sensitive method was established by using this material as adsorbent of mini-solid phase extraction. The limit of detection was as low as 0.02 µg mL-1. Therefore, melamine modified metal-organic framework is an ideal adsorbent for the recognition and enrichment of aristolochic acid Ⅰ.

An Ultrasoft Self-Fused Supramolecular Polymer Hydrogel for Completely Preventing Postoperative Tissue Adhesion.

The intermolecular H-bonding density heavily influences the gelation and rheological behavior of hydrogen-bonded supramolecular polymer hydrogels, thus offering a delicate pathway to tailor their physicochemical properties for meeting a specific biomedical application. Herein, one methylene spacer between two amides in the side chain of N-acryloyl glycinamide (NAGA) is introduced to generate a variant monomer, N-acryloyl alaninamide (NAAA). Polymerization of NAAA in aqueous solution affords an unprecedented ultrasoft and highly swollen supramolecular polymer hydrogel due to weakened H-bonds caused by an extra methylene spacer, which is verified by variable-temperature Fourier transform infrared (FTIR) spectroscopy and simulation calculation. Intriguingly, poly(N-acryloyl alaninamide) (PNAAA) hydrogel can be tuned to form a transient network with a self-fused and excellent antifouling capability that results from the weakened dual amide H-bonding interactions and enhanced water-amide H-bonding interactions. This self-fused PNAAA hydrogel can completely inhibit postoperative abdominal adhesion and recurrent adhesion after adhesiolysis in vivo. This transient hydrogel network allows for its disintegration and excretion from the body. The molecular mechanism studies reveal the signal pathway of PNAAA hydrogel in inhibiting inflammatory response and regulating fibrinolytic system balance. This self-fused, antifouling ultrasoft supramolecular hydrogel is promising as a barrier biomaterial for completely preventing postoperative tissue adhesion.

Berberine improves colitis by triggering AhR activation by microbial tryptophan catabolites.

Inflammatory bowel diseases (IBD) are kind of recurrent inflammatory issues that occur in the gastrointestinal tract, and currently clinical treatment is still unideal due to the complex pathogenesis of IBD. Basically, gut barrier dysfunction is triggered by gut microbiota dysbiosis that is closely associated with the development of IBD, we thus investigated the therapeutic capacity of berberine (BBR) to improve the dysregulated gut microbiota, against IBD in rats, using a combinational strategy of targeted metabolomics and 16 s rDNA amplicon sequencing technology. Expectedly, our data revealed that BBR administration could greatly improve the pathological phenotype, gut barrier disruption, and the colon inflammation in rats with dextran sulfate sodium (DSS)-induced colitis. In addition, 16S rDNA-based microbiota analysis demonstrated that BBR could alleviate gut dysbiosis in rats. Furthermore, our targeted metabolomics analysis illustrated that the levels of microbial tryptophan catabolites in the gastrointestinal tract were significantly changed during the development of the colitis in rats, and BBR treatment can significantly restore such changes of the tryptophan catabolites accordingly. At last, our in vitro mechanism exploration was implemented with a Caco-2 cell monolayer model, which verified that the modulation of the dysregulated gut microbiota to change microbial metabolites coordinated the improvement effect of BBR on gut barrier disruption in the colitis, and we also confirmed that the activation of AhR induced by microbial metabolites is indispensable to the improvement of gut barrier disruption by BBR. Collectively, BBR has the capacity to treat DSS-induced colitis in rats through the regulation of gut microbiota associated tryptophan metabolite to activate AhR, which can greatly improve the disrupted gut barrier function. Importantly, our finding elucidated a novel mechanism of BBR to improve gut barrier function, which holds the expected capacity to promote the BBR derived drug discovery and development against the colitis in clinic setting.

Bursicon mediates antimicrobial peptide gene expression to enhance crowded larval prophylactic immunity in the oriental armyworm, Mythimna separata.

It has been reported that a high population density alters insect prophylactic immunity. Bursicon plays a key role in the prophylactic immunity of newly emerged adults. In this paper, full-length cDNAs encoding the alpha and beta subunits of bursicon in Mythimna separata larvae (Msburs α and Msburs ß) were identified. The cDNAs of Msburs α and Msburs ß contain open reading frames (ORFs) encoding 145- and 139-amino acid residue proteins, respectively. Multiple alignment sequences and phylogenetic analysis indicated that Msbursicons (Msburs α and Msburs ß) are orthologous to bursicons in other lepidopterans. The Msbursicons were expressed throughout all developmental states with higher relative expression during the egg, pupae, and adult stages. Msbursicons (Msburs α and Msburs ß) were highly expressed in the ventral nerve cord and brain relative to other tested tissues. Msbursicon expression of larvae subject to high-density treatment (10 larvae per jar) was significantly increased compared with that of the larvae subject to low-density treatment (1 larva per jar) in the whole fourth and fifth instar stages. The trend in the expression of the antimicrobial peptide (AMP) genes cecropin C and defensin in the test stage was accorded and delayed with increased expression of bursicons. Silencing Msburs α (or Msburs ß) expression by dsRNA injection in larvae subject to high-density treatment significantly decreased the expression levels of the cecropin C and defensin genes. Recombinant Msbursicon homodimers significantly induced the expression of the cecropin C and defensin genes. There was a notable decrease in the survival rate of the Msburs α (or Msburs ß or Mscecropin C or Msdefensin) knockdown larvae infected by Beauveria thuringiensis. Our findings provide the first insights into how larval density mediates AMP gene expression, which subsequently affects the prophylactic immunity of insects under high-density conditions.

Effects of Larval Density on Plutella xylostella Resistance to Granulosis Virus.

It has been reported that some phase-polyphenic insects from high-density conditions are more resistant to pathogens than those from low-density conditions. This phenomenon is termed "density-dependent prophylaxis" (DDP). However, whether non phase-polyphenic insects exhibit DDP has rarely been elucidated. The diamondback moth (DBM), Plutella xylostella, one of the most destructive insect pests affecting cruciferous crops, is non phase-polyphenic. In this study, the resistance of DBM larvae to P. xylostella granulosis virus (Plxy GV) and their immune response to the virus when reared at densities of 1, 2, 5, 10, 15, and 20 larvae per Petri dish were investigated under laboratory conditions. Compared with larvae reared at lower densities, larvae reared at moderate density showed a significantly higher survival rate, but the survival rate significantly decreased with further increases in rearing density. Furthermore, the phenoloxidase, lysozyme and antibacterial activity and total hemocyte count in the hemolymph of the larvae, regardless of whether they were challenged with the virus, from different larval densities corresponded to the observed differences in resistance to Plxy GV. These results demonstrated that P. xylostella larvae exhibited DDP within a certain limited density. This study may help to elucidate the biocontrol effect of different density populations of P. xylostella by granulosis virus and guide improvements in future management strategy.

Cell Metabolomics Reveals Berberine-Inhibited Pancreatic Cancer Cell Viability and Metastasis by Regulating Citrate Metabolism.

Pancreatic cancer (PC) is becoming one of the deadliest cancers, with mortality among the highest worldwide because of its pathogenic latency and the lack of efficient drugs in the clinic. Considering that cancer cells undergo proliferation and differentiation at substantial metabolic costs, as indicated by dysregulated glycolysis and an abnormal TCA cycle induced by mitochondrial damage, we investigated the therapeutic capacity of berberine (BBR) in pancreatic cancer using a cell metabolomics method. A phenotypic assay revealed the significant inhibitory role of BBR in PC cell viability and metastasis. In addition, a precision-targeted metabolome assay showed that BBR profoundly dysregulated the energy metabolism of PC cells, and phenotypic observations based on imaging indicated that PC cell mitochondria were markedly damaged after BBR treatment. Notably, citrate metabolism and transportation in cell mitochondria were significantly influenced by BBR, which led to the blocked biosynthesis of the defined fatty acids (FAs) through the regulation of ACLY, ACO1, and SLC25A1. Therefore, the regulatory effects of FAs on PC cell proliferation and metastasis may be regulated by BBR through targeting citrate metabolism. Collectively, our in vitro data preliminarily reveals the therapeutic potential of BBR against pancreatic cancer by targeting citrate metabolism, citrate might be a new target for drug development and the treatment against PC, but further experimental verification will be required subsequently. Moreover, our study demonstrated that the cell metabolomics method pertains to the capacity to rapidly explore biochemical functions of natural products.

Immunological regulation by a ß-adrenergic-like octopamine receptor gene in crowded larvae of the oriental Armyworm, Mythmina separata.

Recent reports demonstrate that octopamine plays an important immunological role in crowded larvae of the Oriental Armyworm, Mythmina separata. We identified an octopamine receptor, the ß-adrenergic-like gene (designated MsOctß2R), with a 1191 bp open reading frame that encodes 396 amino acids and contains seven conserved hydrophobic transmembrane domains. Multiple sequence alignments and a phylogenetic analysis indicated that MsOctß2R was orthologous to Octß2R that is present in other lepidopterans. MsOctß2R was expressed throughout all developmental stages with higher relative expression during the fourth instar and adult stages. MsOctß2R was highly expressed in the ventral nerve cord and the fat body relative to other examined tissues. Elevated MsOctß2R expression was observed in larvae that were under higher-density conditions (7 and 10 larvae per jar). Silencing MsOctß2R expression via dsRNA injections in larvae from higher-density conditions significantly decreased phenoloxidase (PO) and lysozyme activity, total haemocyte counts, and survival rates against Beauveria bassiana infections (54.06%, 9.91%, 36.22%, and 23.53%, respectively) when compared with control larvae. These results suggest that high-density conditions might alter prophylactic immunity in larvae by regulating the MsOctß2R gene in M. separara and provide new insights into density-dependent prophylaxis in insects.

Route of intestinal absorption and tissue distribution of iron contained in the novel phosphate binder ferric citrate.

BACKGROUND: Anemia of chronic kidney disease (CKD) is, in part, caused by hepcidin-mediated impaired iron absorption. However, phosphate binder, ferric citrate (FC) overcomes the CKD-induced impairment of iron absorption and increases serum iron, transferrin saturation, and iron stores and reduces erythropoietin requirements in CKD/ESRD patients. The mechanism and sites of intestinal absorption of iron contained in FC were explored here. METHODS: Eight-week old rats were randomized to sham-operated or 5/6 nephrectomized (CKD) groups and fed either regular rat chow or rat chow containing 4% FC for 6 weeks. They were then euthanized, and tissues were processed for histological and biochemical analysis using Prussian blue staining, Western blot analysis to quantify intestinal epithelial tight junction proteins and real-time PCR to measure Fatty Acid receptors 2 (FFA2) and 3 (FFA3) expressions. RESULTS: CKD rats exhibited hypertension, anemia, azotemia, and hyperphosphatemia. FC-treated CKD rats showed significant reductions in blood pressure, serum urea, phosphate and creatinine levels and higher serum iron and blood hemoglobin levels. This was associated with marked increase in iron content of the epithelial and subepithelial wall of the descending colon and modest iron deposits in the proximal tubular epithelial cells of their remnant kidneys. No significant difference was found in hepatic tissue iron content between untreated and FC-treated CKD or control groups. Distal colon's epithelial tight Junction proteins, Occludin, JAM-1 and ZO-1 were markedly reduced in the CKD groups. The FFA2 expression in the jejunum and FFA3 expression in the distal colon were significantly reduced in the CKD rats and markedly increased with FC administration. CONCLUSION: Iron contained in the phosphate binder, FC, is absorbed by the distal colon of the CKD animals via disrupted colonic epithelial barrier and upregulation of short chain fatty acid transporters.

Comparative pharmacokinetics of verapamil and norverapamil in normal and ulcerative colitis rats after oral administration of low and high dose verapamil by UPLC-MS/MS.

In this study, UC rat model was established by administration of 5% (w/v) dextran sulfate sodium, and the pharmacokinetics of verapamil and norverapamil were evaluated in normal and UC rats using UPLC-MS/MS after oral administration of 5 mg/kg and 50 mg/kg verapamil.The peak concentration (Cmax) and the area under plasma concentration-time curves (AUC) of verapamil in UC rats after oral administration of 5 mg/kg were significantly greater (2.5 times and 2 times, respectively) than those in normal rats, but the clearance rate (Cl) was significantly lower (by 50%). For norverapamil, Cmax and AUC were significantly greater (2.8 times and 2.5 times, respectively), and Cl was significantly lower (by 45%). But, pharmacokinetic parameters of verapamil and norverapamil after oral administration of 50 mg/kg were no significant differences between UC and normal rats.The better absorption and poor excretion for low-dose verapamil may be attributed to down-regulation of P-gp expression in the intestine and kidney. No significant differences of pharmacokinetic parameters for high-dose verapamil may be explained as the saturation of an efflux mechanism.The findings of this study suggested that in UC patients, doses of verapamil should be decreased when low-dose verapamil was orally administrated.

Ferric Citrate Attenuates Cardiac Hypertrophy and Fibrosis in a Rat Model of Chronic Kidney Disease.

INTRODUCTION: Chronic kidney disease (CKD) promotes hypertrophy and fibrosis in heart, and increases the risk of cardiovascular mortality. Ferric citrate is a dietary phosphate binder used to control hyperphosphatemia in CKD patients. It has been shown to raise iron stores, improve anemia and secondary hyperparathyroidism, and decrease vascular calcification in CKD patients. The present study was done to explore the effects and mechanism of actions of ferric citrate on cardiac hypertrophy and fibrosis. MATERIALS AND METHODS: Male SD rats were randomized to CKD (5/6 nephrectomized) and sham-operated control groups. CKD rats were fed regular diet or a diet containing 4% ferric citrate. After 8 weeks, hemoglobin, renal function and cardiovascular endpoints including blood pressure, heart/body weight ratio, serum N-terminal prohormone of brain natriuretic peptide (NT-proBNP), cardiac histology and markers of hypertrophy, fibrosis and inflammation were assessed. RESULTS: Compared to the controls, untreated CKD group exhibited hypertension, elevated serum urea, creatinine, phosphate, and NT-proBNP concentrations, anemia, cardiomegaly ,cardiac hypertrophy and fibrosis. Treatment with ferric citrate significantly increased hemoglobin and serum iron concentrations, reduced serum phosphate and NT-proBNP levels and ameliorated hypertension, heart/body weight ratio, cardiac hypertrophy, fibrosis and inflammation. In addition, ferric citrate administration reduced the size of cardiomyocytes and expressions of myocardin, transforming growth factor-ß, interleukin-6 and monocyte chemotactic protein 1. CONCLUSIONS: Treatment with ferric citrate attenuated renal failure and cardiovascular abnormalities including myocardial hypertrophy and fibrosis in CKD rats.

The Role of Tyramine ß-Hydroxylase in Density Dependent Immunityof Oriental Armyworm (Mythmina separata) Larva.

High population density alters insect prophylactic immunity, with density-dependent prophylaxis (DDP) being reported in many polyphonic insects. However, the molecular mechanism for DDP remains unclear. In current study, the role of tyramine ß-hydroxylase (Tßh) in the immune response of M. separata larvae that were subject to different rearing densities conditions was investigated. The tyramine ß-hydroxylase activity of larvae from high density treatments (10 and 30 larvae per jar) was significantly higher than that of the larvae from low density treatments (one, two, and five larvae/jar). A tyramine ß-hydroxylase (designated MsTßh) containing a 1779 bp open reading frame was identified. Multiple sequence alignment and phylogenetic analysis indicated that MsTßh was orthologous to the Tßh that was found in other lepidopterans. Elevated MsTßh expression was observed in larvae under high density (10 larvae per jar). Silencing MsTßh expression by the injection of dsRNA in larvae from the high density treatment produced a 25.1% reduction in octopamine levels, while at the same time, there was a significant decrease in phenoloxidase (PO) and lysozyme activity, total haemocyte counts, and survival against Beauveria infection 56.6%, 88.5%, 82.0%, and 55.8%, respectively, when compared to control larvae. Our findings provide the first insights into how MsTßh mediates the octopamine level, which in turn modulates the immune response of larvae under different population densities.