Background & Aims Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Mouse models of NAFLD have been used in studies of pathogenesis and ...treatment, and have certain features of the human disease. We performed a systematic transcriptome-wide analysis of liver tissues from patients at different stages of NAFLD progression (ranging from healthy obese individuals to those with steatosis), as well as rodent models of NAFLD, to identify those that most closely resemble human disease progression in terms of gene expression patterns. Methods We performed a systematic evaluation of genome-wide messenger RNA expression using liver tissues collected from mice fed a standard chow diet (controls) and 9 mouse models of NAFLD: mice on a high-fat diet (with or without fructose), mice on a Western-type diet, mice on a methionine- and choline-deficient diet, mice on a high-fat diet given streptozotocin, and mice with disruption of Pten in hepatocytes. We compared gene expression patterns with those of liver tissues from 25 patients with nonalcoholic steatohepatitis (NASH), 27 patients with NAFLD, 15 healthy obese individuals, and 39 healthy nonobese individuals (controls). Liver samples were obtained from patients undergoing liver biopsy for suspected NAFLD or NASH, or during liver or bariatric surgeries. Data sets were analyzed using the limma R-package. Overlap of functional profiles was analyzed by gene set enrichment analysis profiles. Results We found differences between human and mouse transcriptomes to be significantly larger than differences between disease stages or models. Of the 65 genes with significantly altered expression in patients with NASH and 177 genes with significantly altered expression in patients with NAFLD, compared with controls, only 1–18 of these genes also differed significantly in expression between mouse models of NAFLD and control mice. However, expression of genes that regulate pathways associated with the development of NAFLD were altered in some mouse models (such as pathways associated with lipid metabolism). On a pathway level, gene expression patterns in livers of mice on the high-fat diet were associated more closely with human fatty liver disease than other models. Conclusions In comparing gene expression profiles between liver tissues from different mouse models of NAFLD and patients with different stages of NAFLD, we found very little overlap. Our data set is available for studies of pathways that contribute to the development of NASH and NAFLD and selection of the most applicable mouse models ( http://www.nash-profiler.com ).
Endoscopic ultrasound-guided biliary drainage (EUS-BD) might be an alternative to percutaneous or transpapillary biliary drainage in unresectable pancreatic or biliary cancer. A lumen-apposing, fully ...covered, self-expanding metal stent, which creates a sealed transluminal conduit between the biliary and gastrointestinal tract may offer advantages over conventional plastic and metal stents. In this retrospective, observational, open-label case study, five patients underwent EUS-BD for obstructive jaundice in pancreatic cancer (n = 4) or distal cholangiocarcinoma (n = 1). Technical and functional success was achieved in all patients without complications. The development of specialized stent and delivery systems may render EUS-BD an effective and safe alternative to percutaneous or transpapillary approaches.
In the budding yeast Saccharomyces cerevisiae, self-recognition and the thereby promoted aggregation of thousands of cells into protective flocs is mediated by a family of cell-surface adhesins, the ...flocculins (Flo). Based on this social behavior FLO genes fulfill the definition of "greenbeard" genes, which direct cooperation toward other carriers of the same gene. The process of flocculation plays an eminent role in the food industry for the production of beer and wine. However, the precise mode of flocculin-mediated surface recognition and the exact structure of cognate ligands have remained elusive. Here, we present structures of the adhesion domain of a flocculin complexed to its cognate ligands derived from yeast high-mannose oligosaccharides at resolutions up to 0.95 Å. Besides a PA14-like architecture, the Flo5A domain reveals a previously undescribed lectin fold that utilizes a unique DcisD calcium-binding motif for carbohydrate binding and that is widely spread among pro- and eukaryotes. Given the high abundance of high-mannose oligosaccharides in yeast cell walls, the Flo5A structure suggests a model for recognition, where social non-self-instead of unsocial self-interactions are favored.
Microorganisms have evolved specific cell surface molecules that enable discrimination between cells from the same and from a different kind. Here, we investigate the role of Flo11-type cell surface ...adhesins from social yeasts in kin discrimination. We measure the adhesion forces mediated by Flo11A-type domains using single-cell force spectroscopy, quantify Flo11A-based cell aggregation in populations and determine the Flo11A-dependent segregation of competing yeast strains in biofilms. We find that Flo11A domains from diverse yeast species confer remarkably strong adhesion forces by establishing homotypic interactions between single cells, leading to efficient cell aggregation and biofilm formation in homogenous populations. Heterotypic interactions between Flo11A domains from different yeast species or
strains confer weak adhesive forces and lead to efficient strain segregation in heterogenous populations, indicating that in social yeasts Flo11A-mediated cell adhesion is a major mechanism for kin discrimination at species and sub-species levels. These findings, together with our structure and mutation analysis of selected Flo11A domains, provide a rationale of how cell surface receptors have evolved in microorganisms to mediate kin discrimination.
In the yeast
and other ascomycetes, the maintenance of cell wall integrity is governed by a family of plasma-membrane spanning sensors that include the Wsc-type proteins. These cell wall proteins ...apparently sense stress-induced mechanical forces at the cell surface and target the cell wall integrity (CWI) signaling pathway, but the structural base for their sensor function is yet unknown. Here, we solved a high-resolution crystal structure of the extracellular cysteine-rich domain (CRD) of yeast Wsc1, which shows the characteristic PAN/Apple domain fold with two of the four Wsc1 disulfide bridges being conserved in other PAN domain cores. Given the general function of PAN domains in mediating protein-protein and protein-carbohydrate interactions, this finding underpins the importance of Wsc domains in conferring sensing and localization functions. Our Wsc1 CRD structure reveals an unusually high number of surface-exposed aromatic residues that are conserved in other fungal CRDs, and can be arranged into three solvent-exposed clusters. Mutational analysis demonstrates that two of the aromatic clusters are required for conferring
Wsc1-dependent resistance to the glucan synthase inhibitor caspofungin, and the chitin-binding agents Congo red and Calcofluor white. These findings suggest an essential role of surface-exposed aromatic clusters in fungal Wsc-type sensors that might include an involvement in stress-induced sensor-clustering required to elicit appropriate cellular responses via the downstream CWI pathway.
Although extramedullary manifestations (EMs) are frequent in patients with acute myeloid leukemia (AML), they are often not detected during clinical workup and neither imaging- nor molecularly based ...diagnostic strategies are established to reveal their existence. Still, the detection of EM is essential for therapeutic decision-making, as EM present with aggressive and resistant disease and since mutational profiling might render patients within a different risk category, requiring personalized therapeutic strategies. Here, we report the case of an AML patient presenting with AML bone marrow (BM) infiltration and molecularly distinct EM at time of diagnosis followed by multiple EM relapses while undergoing several intensive chemotherapies including allogeneic hematopoietic cell transplantations (alloHCTs). 18Fluorodesoxy-glucose positron emission tomography (18FDG-PET)-imaging revealed EM sites in the mediastinum, duodenum, skin, and in retroperitoneal tissue, whereas recurrent BM biopsies showed continuous cytomorphologic and cytogenetic remission after alloHCT. To investigate the molecular background of the aggressive character of extramedullary disease and its differential treatment response, we performed amplicon-based next generation sequencing. An exon 4 (c.497_498insGA) frameshift RUNX1 mutation was exclusively found in all of the patient’s EM sites, but not in the BM or in peripheral blood samples at time of EM reoccurrence. In addition, we detected an exon 13 (c.3306G>T) ASXL1 point mutation only in the retroperitoneal tumor tissue at the time of the fourth relapse. In contrast to the patient’s intermediate-risk BM AML at diagnosis according to ELN2017, EM sites showed molecular adverse-risk features implicating intensified strategies like cellular therapies. Notably, disease relapse could only be detected by imaging throughout the course of disease. This case demonstrates both the necessity of continuous molecular profiling of EM to reveal differential molecular composition of EM and BM-derived AML, supposedly leading to divergent susceptibility to established therapies, as well as recurrent 18FDG-PET-imaging for detecting residual disease and assessment of treatment response in case of EM AML.
Cell-cell and cell-substrate based adhesion of yeasts are major determinants of their adoption of different life styles. Genome-mining of ascomycetous GPI-anchored cell wall proteins with lectin-like ...PA14 domains identified a unique class of putative adhesins in the clade of methylotrophic
yeasts, many of which are known to colonize plants and insects involving yet unknown adhesion mechanisms. Here, we report the functional and structural analysis of two of its members:
Flo1 (=Cea1), that is highly specific for terminal
-acetylglucosamine moieties, and
Flo2, which represents an orphan lectin with intact binding site but unknown specificity. Crystal structures of the Cea1 adhesion domain complexed to
-acetylglucosamine and
,
'-diacetylchitobiose reveal a Ca
-dependent binding mode that differs from other members of the PA14/Flo5 adhesin family. Heterologous expression of Cea1A in
promotes cellular adhesion to non-reducing ends of non-crystalline chitin. Overall, our data suggest that high-affinity recognition of β-GlcNAc-capped glycans by Cea1 enable
species to interact with surface cues present in fungi and insects.
Lumen-apposing metal stents (LAMSs) play an increasing role in transgastric and transduodenal drainage of pancreatic fluid collections and allow novel EUS-guided interventions. Alongside the main ...adverse events of bleeding and occlusion, LAMSs can be overgrown by mucosa, which leads to the inability to visualize the stent in endoscopy.
We describe a series of 4 cases of buried LAMSs that were removed under EUS guidance for identification of the stent followed by removal with rat-tooth forceps.
The median in situ time of the LAMSs in the reported 4 cases was 53 days. All stents could no longer be visualized endoscopically when drainage of necrosis was complete. All 4 buried LAMSs could be identified by EUS and were removed successfully with forceps. In 1 case, balloon dilation of the stent tract was performed before stent removal. No adverse events were observed after the procedure.
Buried stent syndrome is a rare adverse event of LAMSs. Here we describe a safe and effective approach for stent identification and removal without prior mucosal dissection.
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