Chronic intestinal inflammation significantly contributes to the development of colorectal cancer and remains a pertinent clinical challenge, necessitating novel therapeutic approaches. Indole-based microbial metabolite mimics Felix Kopp Kortagere 6 (FKK6), which is a ligand and agonist of the pregnane X receptor (PXR), was recently demonstrated to have PXR-dependent anti-inflammatory and protective effects in a mouse model of dextran sodium sulfate (DSS)-induced acute colitis. Here, we examined the therapeutic potential of FKK6 in a mouse model (C57BL/6 FVB humanized PXR mice) of colitis-associated colon cancer (CAC) induced by azoxymethane and DSS. FKK6 (2 mg/kg) displayed substantial antitumor activity, as revealed by reduced size and number of colon tumors, improved colon histopathology, and decreased expression of tumor markers (c-MYC, β-catenin, Ki-67, and cyclin D) in the colon. In addition, we carried out a chronic toxicity (30 days) assessment of FKK6 (1 mg/kg and 2 mg/kg) in C57BL/6 mice. Histological examination of tissues, biochemical blood analyses, and immunohistochemical staining for Ki-67 and γ-H2AX showed no difference between FKK6-treated and control mice. Comparative metabolomic analyses in mice exposed for 5 days to DSS and administered with FKK6 (0.4 mg/kg) revealed no significant effects on several classes of metabolites in the mouse fecal metabolome. Ames and micronucleus tests showed no genotoxic and mutagenic potential of FKK6 in vitro. In conclusion, anticancer effects of FKK6 in azoxymethane/DSS-induced CAC, together with FKK6 safety data from in vitro tests and in vivo chronic toxicity study, and comparative metabolomic study, are supportive of the potential therapeutic use of FKK6 in the treatment of CAC. SIGNIFICANCE STATEMENT: Microbial metabolite mimicry proposes that chemical mimics of microbial metabolites that serve to protect hosts against aberrant inflammation in the gut could serve as a new paradigm for the development of drugs targeting inflammatory bowel disease if, like the parent metabolite, is devoid of toxicity but more potent against the microbial metabolite receptor. We identified a chemical mimic of Felix Kopp Kortagere 6, and we propose that Felix Kopp Kortagere 6 is devoid of toxicity yet significantly reduces tumor formation in an azoxymethane-dextran sodium sulfate model of murine colitis-induced colon cancer.
- MeSH
- Azoxymethane toxicity MeSH
- Chronic Disease MeSH
- Indoles pharmacology therapeutic use MeSH
- Colitis drug therapy chemically induced metabolism pathology MeSH
- Colorectal Neoplasms * drug therapy metabolism pathology MeSH
- Disease Models, Animal * MeSH
- Molecular Mimicry MeSH
- Mice, Inbred C57BL * MeSH
- Mice MeSH
- Colitis-Associated Neoplasms pathology drug therapy metabolism MeSH
- Dextran Sulfate toxicity MeSH
- Inflammation drug therapy metabolism MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Frequent degenerative joint diseases, known as arthritis, are characterized by joint inflammation and cartilage breakdown. Various arthritis types are traditionally managed with intraarticular injections of hyaluronan or its derivatives. However, intravenous administration of hyaluronan is emerging as a vital alternative, particularly because intraarticular injections can be challenging for clinicians when targeting small or swollen joints. Pharmacokinetics of intravenously and intraperitoneally administered middle-Mw hyaluronan were studied in an adjuvant-induced arthritis mouse model alongside therapeutic effects. Using 13C-, biotin- and fluoresce-labeling, we found hyaluronan accumulated in inflamed joint tissues while distribution in other organs remained similar to healthy controls. Repeated administrations significantly reduced arthritis symptoms like swelling and redness, RANKL, inducible nitric oxide synthase, COMP and prostaglandin E2 levels. Moreover, hyaluronan treatment prevented dextran-FITC penetration into inflamed paws suggesting reduced vascular permeability at the site of inflammation. These findings support systemic hyaluronan administration as a promising arthritis treatment strategy.
- MeSH
- Arthritis, Experimental * drug therapy pathology metabolism MeSH
- Joints drug effects pathology metabolism MeSH
- Hyaluronic Acid * pharmacokinetics administration & dosage pharmacology therapeutic use MeSH
- Disease Models, Animal MeSH
- Mice MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND & AIMS: Exogenous recombinant fibroblast growth factor 20 (FGF20) protein has been proved to treat ulcerative colitis; however, its mechanism of action remains unclear. This study aimed to explore the role and mechanism of action of FGF20 in ulcerative colitis. METHODS: Data from patients with ulcerative colitis were analyzed using the Gene Expression Omnibus dataset. A murine colitis model was established by administering 2% dextran sodium sulfate. FGF20 knockout mice and Adenoassociated viruses (AAV)-FGF20-treated mice were used to elucidate the specific mechanisms. Proteomic analysis was conducted to identify differentially expressed genes. RESULTS: FGF20 levels were significantly elevated in the colonic tissues of subjects and mice with colitis. FGF20 deficiency exacerbated dextran sodium sulfate-induced colitis; in contrast, FGF20 replenishment alleviated colitis through 2 principal mechanisms: restoration of impaired intestinal epithelial barrier integrity, and inhibition of M1 macrophage polarization. Notably, S100A9 was identified as a pivotal downstream target of FGF20, which was further demonstrated by pharmacologic inhibition and overexpression experiments of S100A9 using paquinimod (a specific inhibitor of S100A9) and AAV-S100A9 in FGF20 knockout and AAV-FGF20 mice with colitis, respectively. Additionally, the nuclear factor-κB pathway was found to be involved in the process by which FGF20 regulates S100A9 to counteract colitis. CONCLUSIONS: These results suggest that FGF20 acts as a negative regulator of S100A9 and nuclear factor-κB, thereby inhibiting M1 macrophage polarization and restoring intestinal epithelial barrier integrity in mice with dextran sodium sulfate-induced colitis. FGF20 may serve as a potential therapeutic target for the treatment of ulcerative colitis.
- MeSH
- Fibroblast Growth Factors * metabolism genetics pharmacology MeSH
- Calgranulin B * metabolism genetics MeSH
- Colitis * chemically induced MeSH
- Humans MeSH
- Macrophages * immunology metabolism drug effects MeSH
- Disease Models, Animal MeSH
- Mice, Inbred C57BL MeSH
- Mice, Knockout MeSH
- Mice MeSH
- NF-kappa B * metabolism MeSH
- Signal Transduction MeSH
- Dextran Sulfate toxicity MeSH
- Intestinal Mucosa * pathology metabolism immunology drug effects MeSH
- Colitis, Ulcerative * pathology chemically induced immunology metabolism drug therapy MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Background: Parkinson's disease (PD) is intricately linked to gastrointestinal inflammation and the presence of neurotoxins in the gut, integrating α-syn pathologic alterations and subsequent neurodegeneration into the brain. Objectives: This study aimed to explore the enduring impact of dextran sodium sulfate (DSS)-mediated colitis on the vulnerability of central dopaminergic neurons to subsequent rotenone exposure. Methods: To induce chronic colitis, 10-month-old C57BL/6 mice were pre-exposed to 3 cycles of 1 week of 1% (w/v) DSS administration in drinking water followed by 2 weeks of regular drinking water. After colitis induction, animals received a low dose of intragastric rotenone for the next 8 weeks, followed by testing for Parkinsonian behavior and GI phenotypes of inflammation. At the end of the 17th week, colon, brain stem, and midbrain tissue were isolated and analyzed for α-syn, inflammatory markers, and dopaminergic neuronal loss. Gut microbial composition was assessed by 16S rRNA sequencing analysis. Results: We found that chronic rotenone administration in the presence of preexisting colitis led to a further increase in colonic pro-inflammatory mediator expressions, α-syn expression, and reduced colonic tight junction protein expressions. We also found early impairment of GI functions and worsened grip strength in rotenone-exposed colitic mice. Furthermore, α-syn pathology specific to the colitic mice exposed to rotenone showed dopaminergic neurons degeneration and astroglial activation in substantia nigra and striatum, including regions of the brain stem, i.e., dorsal motor of the vagus and locus coeruleus. Finally, the result of 16S rRNA gene sequencing analysis indicated that colitic mice, after being exposed to rotenone, exhibited a discernible trend in their microbiota composition (Catenibacterium, Turicibactor, and clostridium sensue stricto 1), linking it to the development of PD. Conclusions: These findings indicate that prolonged low-dose rotenone exposure, combined with an early inflammatory intestinal milieu, provides a preconditioning effect on α-syn pathology and exerts neurodegeneration in the intragastric rotenone PD mouse model.
- Publication type
- Journal Article MeSH
A subpopulation of astrocytes on the brain's surface, known as subpial astrocytes, constitutes the "glia limitans superficialis" (GLS), which is an interface between the brain parenchyma and the cerebrospinal fluid (CSF) in the subpial space. Changes in connexin-43 (Cx43) and aquaporin-4 (AQP4) proteins in subpial astrocytes were examined in the medial prefrontal cortex at postoperative day 1, 3, 7, 14, and 21 after sham operation and sciatic nerve compression (SNC). In addition, we tested the altered uptake of TRITC-conjugated 3 kDa dextran by reactive subpial astrocytes. Cellular immunofluorescence (IF) detection and image analysis were used to examine changes in Cx43 and AQP4 protein levels, as well as TRITC-conjugated 3 kDa dextran, in subpial astrocytes. The intensity of Cx43-IF was significantly increased, but AQP4-IF decreased in subpial astrocytes of sham- and SNC-operated rats during all survival periods compared to naïve controls. Similarly, the uptake of 3 kDa dextran in the GLS was reduced following both sham and SNC operations. The results suggest that both sciatic nerve injury and peripheral tissue injury alone can induce changes in subpial astrocytes related to the spread of their reactivity across the cortical surface mediated by increased amounts of gap junctions. At the same time, water transport and solute uptake were impaired in subpial astrocytes.
- MeSH
- Aquaporin 4 * metabolism MeSH
- Astrocytes * metabolism MeSH
- Dextrans * metabolism MeSH
- Connexin 43 * metabolism MeSH
- Rats MeSH
- Sciatic Nerve * injuries metabolism MeSH
- Rats, Sprague-Dawley MeSH
- Prefrontal Cortex * metabolism MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Fibrosis contributes to tissue repair, but excessive fibrosis disrupts organ function. Alagille syndrome (ALGS, caused by mutations in JAGGED1) results in liver disease and characteristic fibrosis. Here, we show that Jag1Ndr/Ndr mice, a model for ALGS, recapitulate ALGS-like fibrosis. Single-cell RNA-seq and multi-color flow cytometry of the liver revealed immature hepatocytes and paradoxically low intrahepatic T cell infiltration despite cholestasis in Jag1Ndr/Ndr mice. Thymic and splenic regulatory T cells (Tregs) were enriched and Jag1Ndr/Ndr lymphocyte immune and fibrotic capacity was tested with adoptive transfer into Rag1-/- mice, challenged with dextran sulfate sodium (DSS) or bile duct ligation (BDL). Transplanted Jag1Ndr/Ndr lymphocytes were less inflammatory with fewer activated T cells than Jag1+/+ lymphocytes in response to DSS. Cholestasis induced by BDL in Rag1-/- mice with Jag1Ndr/Ndr lymphocytes resulted in periportal Treg accumulation and three-fold less periportal fibrosis than in Rag1-/- mice with Jag1+/+ lymphocytes. Finally, the Jag1Ndr/Ndr hepatocyte expression profile and Treg overrepresentation were corroborated in patients' liver samples. Jag1-dependent hepatic and immune defects thus interact to determine the fibrotic process in ALGS.
- MeSH
- Alagille Syndrome pathology genetics MeSH
- Cell Differentiation * MeSH
- Hepatocytes * metabolism pathology MeSH
- Liver Cirrhosis * pathology genetics MeSH
- Humans MeSH
- Disease Models, Animal MeSH
- Mice, Inbred C57BL MeSH
- Mice, Knockout MeSH
- Mice MeSH
- Jagged-1 Protein * metabolism genetics MeSH
- T-Lymphocytes, Regulatory immunology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Regulation of neuroimmune interactions varies across avian species. Little is presently known about the interplay between periphery and central nervous system (CNS) in parrots, birds sensitive to neuroinflammation. Here we investigated the systemic and CNS responses to dextran sulphate sodium (DSS)- and lipopolysaccharide (LPS)-induced subclinical acute peripheral inflammation in budgerigar (Melopsittacus undulatus). Three experimental treatment groups differing in DSS and LPS stimulation were compared to controls. Individuals treated with DSS showed significant histological intestinal damage. Through quantitative proteomics we described changes in plasma (PL) and cerebrospinal fluid (CSF) composition. In total, we identified 180 proteins in PL and 978 proteins in CSF, with moderate co-structure between the proteomes. Between treatments we detected differences in immune, coagulation and metabolic pathways. Proteomic variation was associated with the levels of pro-inflammatory cytokine mRNA expression in intestine and brain. Our findings shed light on systemic impacts of peripheral low-grade inflammation in birds.
- MeSH
- Central Nervous System * metabolism immunology MeSH
- Cytokines metabolism MeSH
- Lipopolysaccharides * immunology MeSH
- Melopsittacus * immunology MeSH
- Brain metabolism immunology MeSH
- Bird Diseases immunology metabolism MeSH
- Neuroimmunomodulation MeSH
- Neuroinflammatory Diseases immunology MeSH
- Proteome * metabolism MeSH
- Proteomics methods MeSH
- Avian Proteins metabolism genetics MeSH
- Dextran Sulfate * MeSH
- Intestines immunology MeSH
- Inflammation * immunology metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Ulceration colitis (UC) is a chronic and recurrent inflammatory disorder in the gastro-intestinal tract. The purpose of our study is to explore the potential mechanisms of ginsenoside Rg1 (GS Rg1) on dextran sulfate sodium (DSS)-induced colitis in mice and lipopolysaccharide (LPS)-induced RAW 264.7 cells. Acute colitis was induced in male C57BL/6 mice. In vitro model of LPS-induced RAW 264.7 cells to simulate enteritis model. The disease activity index (DAI), colon length, body weight and histopathological analysis were performed in vivo. Pro-inflammatory cytokines and markers for oxidative and anti-oxidative stress, MPO level were measured in vivo and in vitro. Nuclear erythroid 2-related factor 2 (Nrf2) and NF-?B p65 protein levels were analyzed using western blotting. Our results indicated that the UC models were established successfully by drinking DSS water. GS Rg1 significantly attenuated UC-related symptoms, including preventing weight loss, decreasing DAI scores, and increasing colon length. GS Rg1 ameliorated the DSS-induced oxidative stress. IL-1beta, IL-6, and TNF-alpha levels were significantly increased in serum and cell supernatant effectively, while treatment with the GS Rg1 significantly reduced these factors. GS Rg1 reduced MPO content in the colon. GS Rg1 treatment increased SOD and decreased MDA levels in the serum, colon, and cell supernatant. GS Rg1 restored the Nrf-2/HO-1/NF-?B pathway in RAW 264.7 cells and UC mice, and these changes were blocked by Nrf-2 siRNA. Overall, GS Rg1 ameliorated inflammation and oxidative stress in colitis via Nrf-2/HO-1/NF-kappaB pathway. Thus, GS Rg1 could serve as a potential therapeutic agent for the treatment of UC.
- MeSH
- Dextrans metabolism pharmacology therapeutic use MeSH
- Ginsenosides * MeSH
- Colitis * chemically induced MeSH
- Colon metabolism MeSH
- Lipopolysaccharides metabolism MeSH
- Disease Models, Animal MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- NF-kappa B metabolism MeSH
- Dextran Sulfate toxicity metabolism MeSH
- Sulfates * MeSH
- Colitis, Ulcerative * chemically induced drug therapy metabolism MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: The extent to which tryptophan (Trp) metabolism alterations explain or influence the outcome of inflammatory bowel diseases (IBDs) is still unclear. However, several Trp metabolism end-products are essential to intestinal homeostasis. Here, we investigated the role of metabolites from the kynurenine pathway. DESIGN: Targeted quantitative metabolomics was performed in two large human IBD cohorts (1069 patients with IBD). Dextran sodium sulphate-induced colitis experiments in mice were used to evaluate effects of identified metabolites. In vitro, ex vivo and in vivo experiments were used to decipher mechanisms involved. Effects on energy metabolism were evaluated by different methods including Single Cell mEtabolism by profiling Translation inHibition. RESULTS: In mice and humans, intestinal inflammation severity negatively correlates with the amount of xanthurenic (XANA) and kynurenic (KYNA) acids. Supplementation with XANA or KYNA decreases colitis severity through effects on intestinal epithelial cells and T cells, involving Aryl hydrocarbon Receptor (AhR) activation and the rewiring of cellular energy metabolism. Furthermore, direct modulation of the endogenous tryptophan metabolism, using the recombinant enzyme aminoadipate aminotransferase (AADAT), responsible for the generation of XANA and KYNA, was protective in rodent colitis models. CONCLUSION: Our study identified a new mechanism linking Trp metabolism to intestinal inflammation and IBD. Bringing back XANA and KYNA has protective effects involving AhR and the rewiring of the energy metabolism in intestinal epithelial cells and CD4+ T cells. This study paves the way for new therapeutic strategies aiming at pharmacologically correcting its alterations in IBD by manipulating the endogenous metabolic pathway with AADAT.
- MeSH
- Inflammatory Bowel Diseases * drug therapy MeSH
- Colitis * chemically induced drug therapy metabolism MeSH
- Humans MeSH
- Mice MeSH
- Intestines MeSH
- Tryptophan metabolism MeSH
- Inflammation MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: Normothermic ex situ perfusion of vascularized composite allografts (VCAs) necessitates high oxygen demand and, thus, increased metabolic activity, which, in turn, requires the use of blood-based perfusion solutions. However, blood-derived perfusates, in turn, constitute an antigenic load. To circumvent this immunogenic problem, we used a perfusate enriched with acellular dextrane oxygen microcarriers to perfuse rat hindlimbs. METHODS: Rat hindlimbs (n = 11) were perfused with either (non-), oxygenated dextrane-enriched Phoxilium, or Phoxilium enriched with dextrane oxygen microcarriers (MO2) for 12 h at 37 °C or stored on ice. Oxygenation of the skeletal muscle was assessed with Raman spectroscopy, tissue pO2-probes, and analysis of the perfusate. Transmission electronic microscopy was utilized to assess the ultrastructure of mitochondria of the skeletal muscle. RESULTS: For all evaluated conditions, ischemia time until perfusion was comparable (22.91 ± 1.64 min; p = 0.1559). After 12 h, limb weight increased significantly by at least 81%, up to 124% in the perfusion groups, and by 27% in the static cold storage (SCS) group. Raman spectroscopy signals of skeletal muscle did not differ substantially among the groups during either perfusion or static cold storage across the duration of the experiment. While the total number of skeletal muscle mitochondria decreased significantly compared to baseline, mitochondrial diameter increased in the perfusion groups and the static cold storage group. CONCLUSION: The use of oxygen microcarriers in ex situ perfusion of VCA with acellular perfusates under normothermic conditions for 12 h facilitates the maintenance of mitochondrial structure, as well as a subsequent recovery of mitochondrial redox status over time, while markers of muscle injury were lower compared to conventional oxygenated acellular perfusates.
- Publication type
- Journal Article MeSH