Project description:In this study we evaluated the role of hyaluronan (HA) in reactive adipogenesis, a local expansion of preadipocytes that provides host defense by release of antimicrobial peptides. We observed that HA accumulated during maturation of adipocytes in vitro and was associated with increased expression of preadipocyte factor 1 (Pref-1), Zinc finger protein 423 (Zfp423) and early B cell factor 1 (Ebf1). Although HA is normally abundant in the extracellular matrix, a further increase in HA staining occurred in mice at sites of reactive adipogenesis following injury of colon by dextran sodium sulfate or injury of skin from infection with S. aureus. HA also abundantly accumulated around adipocytes seen in the colon of patients with inflammatory bowel disease. This HA was necessary for adipocyte maturation since digestion of HA by administration of soluble hyaluronidase or transgenic expression of hyaluronidase 1 inhibited adipogenesis in vitro and in vivo. Furthermore, hyaluronidase also suppressed inflammation of both skin and colon and decreased antimicrobial peptide expression by developing preadipocytes. This resulted in increased bacterial transit across the epithelial barrier despite decreased tissue injury from inflammation. These observations suggest HA plays an important role in reactive adipogenesis and host defense after injury.
Project description:The spread of inflammation from the skin to the joints is a key issue in the pathogenesis of psoriatic arthritis (PsA). Psoriasis (PsO), one of the most common skin diseases, usually precedes joint manifestations, suggesting skin-joint disease spread, which occurs in about 30% of psoriasis patients. Until now, it has been unclear why the inflammatory process remains restricted to the skin in some patients with PsO, whereas it spreads to tendons and joints in others. Using a preclinical model of PsA, we aimed to elucidate the skin-joint axis, i.e. the spread of psoriatic inflammation from the skin to the joints. KAEDE transgenic mice expressing a photo-convertible fluorescent reporter were used to assess cell trafficking from inflamed skin to other organs in the mouse model of IL-23 overexpression (IL-23OE) induced PsA. Psoriatic skin lesions were irradiated with UV light to induce the photoswitch from KAEDE-GREEN to KAEDE-RED. Migrating cells were characterised by scRNAseq.
Project description:Dysbiosis in the gut microbiota impacts several systemic diseases. One possible mechanism is the migration of perturbed intestinal immunocytes to extra-intestinal tissues. Combining the Kaede photoconvertible mouse model and single-cell genomics, we generated a detailed map of migratory trajectories from the colon, at baseline and during intestinal and extra-intestinal inflammation. All colonic lineages emigrated from the colon in an S1P-dependent manner, dominated by B lymphocytes with a large continuous circulation of follicular B cells, which carried a gut-imprinted transcriptomic signature. T cell emigration was more selective, with distinct groups of RORg+ cells and IEL-like CD160+ T cells in the spleen. Gut inflammation curtailed emigration, except for DCs disseminating to lymph nodes. Colon emigrating cells distributed differentially to tumor, skin inflammation, or arthritic synovium, the former dominated by myeloid cells in a chemokine-dependent manner. These results thus reveal specific cellular trails originating in the gut, influenced by microbiota, which can shape peripheral immunity.
Project description:Vitiligo is a common autoimmune skin disorder. We constructed an induced vitiligo mouse model and performed bulk-RNA sequencing on the skin and 16S rRNA sequencing of feces from vitiligo mice and uninduced mice. Next, we performed skin bulk-RNA sequencing after treatment using ABX. Lastly, we subjected gut microbe-related metabolite hippuric acid to control mice and performed bulk-RNA sequencing on the skin to observe oxidative stress-related gene expression changes.
Project description:The migratory locust, Locusta migratoria, is a serious agricultural pest and important insect model to study insect digestion and feeding behavior. The gut is one of the primary interfaces between the insect and its environment. Nevertheless, knowledge on the gut transcriptome of L. migratoria is still very limited. With the development of two EST databases from L. migratoria (whole body and central nervous system (CNS)) and one EST database from Schistocerca gregaria (CNS), an abundance of transcript data was made available for locusts. In addition, the genome of Locusta was also recently published in an effort to create a better understanding of swarm formation and flight behavior (Wang et al., 2014). While the transcript composition of nervous tissue was relatively well studied after the development of the specific CNS-derived EST-databases from both L. migratoria and S. gregaria, little transcript profiling information is available for the digestive system at the moment. Locusts are, however, widely used as physiological model organisms regarding the regulation and control of feeding and digestion, and improved knowledge on the gut transcriptome could contribute significantly to a better understanding of their gut physiology. Therefore, we aimed to use the available sequence data to specifically identify gut-expressed transcripts in 5th larval locusts. By means of two independent self-self microarray hybridizations for two distinct tissues, the gut and the brain, a selection could be made of those ESTs that are present in the gut and/or the brain. Here, sequences that were found to be expressed in gut but not brain were further functionally annotated to shed new light on the complex physiology of the locust digestive system. Since the gut is the single most important organ in digestion, and both tissues are assumed to be involved in the regulation thereof, the resulting subset of sequences can also be valuable for further in-depth studies on the regulation of digestion. In addition, the method allowed us to rank the signal intensities, using them as a rough indicator to compare relative transcript abundance in the gut. Therefore, the data complement previously published transcript and genomic data, and provide a clear overview of the expressed portion of the genome in the gut. Taken together, the present data provide significant insight into locust larval gut physiology, and will be valuable for future studies on the insect gut. Self-self hybridisation of Cy5- and Cy3-labeled samples. One biological repeat per tissue type, i.e., brain and gut. Gut is a combination of foregut, midgut, gastric caeca and hindgut. Per tissue type, a pool was made from RNA from 3 pools of 5 locusts, and this for 3 different feeding conditions, resulting in samples derived from a total of 45 locust larvae. Feeding conditions were normally fed, fed with diet containing additional protease inhibitors (PIs), and starved locusts.
Project description:The gut and liver are recognized to mutually communicate through the biliary tract, portal vein and systemic circulation, but it remains unclear how this gut-liver axis regulates intestinal physiology. Through hepatectomy, transcriptomic and proteomic profiling, we identified pigment epithelium-derived factor (PEDF), a liver-derived soluble Wnt inhibitor, that restrains intestinal stem cell (ISC) hyperproliferation to maintain gut homeostasis by suppressing the Wnt/b-catenin signaling pathway. Further, we found that microbial danger signals occurring as a result of intestinal inflammation can be sensed by the liver to repress PEDF production via peroxisome proliferator-activated receptor-a (PPARa), liberating ISC proliferation to accelerate tissue repair in the gut. Finally, treatment of mice with fenofibrate, a clinical agent of PPARa agonist for hypolipidemia enhances the susceptibility of colitis via PEDF activity. Therefore, we have identified a distinct role for PEDF in calibrating ISC expansion for intestinal homeostasis via reciprocal interactions between the gut and liver.
Project description:Patients diagnosed with cutaneous and/or gastrointestinal aGvHD provide a unique opportunity to perform an in-depth comparison of activated human CD8+ T cells homing to the gut and skin, in some cases even within the same host, at the same time, acting as key players in the same human disease, and exerting their effector functions in these two tissue environments. This study aims at the identification of novel biomarkers associated with skin- and gut-homing CD8+ T cells in general, and CD8+ T cell markers possibly linked to CTL-mediated skin- and gut damage in aGvHD in particular.
Project description:Morphine and its pharmacological derivatives are the most prescribed analgesics for moderate to severe pain management. However, chronic use of morphine reduces pathogen clearance and induces bacterial translocation across the gut barrier. The enteric microbiome has been shown to play a critical role in the preservation of the mucosal barrier function and metabolic homeostasis. Here, we show for the first time, using bacterial 16s rDNA sequencing, that chronic morphine treatment significantly alters the gut microbial composition and induces preferential expansion of the gram-positive pathogenic and reduction of bile-deconjugating bacterial strains. A significant reduction in both primary and secondary bile acid levels was seen in the gut, but not in the liver with morphine treatment. Morphine induced microbial dysbiosis and gut barrier disruption was rescued by transplanting placebo-treated microbiota into morphine-treated animals, indicating that microbiome modulation could be exploited as a therapeutic strategy for patients using morphine for pain management. In this study, we establish a link between the two phenomena, namely gut barrier compromise and dysregulated bile acid metabolism. We show for the first time that morphine fosters significant gut microbial dysbiosis and disrupts cholesterol/bile acid metabolism. Changes in the gut microbial composition is strongly correlated to disruption in host inflammatory homeostasis13,14 and in many diseases (e.g. cancer/HIV infection), persistent inflammation is known to aid and promote the progression of the primary morbidity. We show here that chronic morphine, gut microbial dysbiosis, disruption of cholesterol/bile acid metabolism and gut inflammation; have a linear correlation. This opens up the prospect of devising minimally invasive adjunct treatment strategies involving microbiome and bile acid modulation and thus bringing down morphine-mediated inflammation in the host.