Hydronidone induces apoptosis in activated hepatic stellate cells through endoplasmic reticulum stress-associated mitochondrial apoptotic pathway.

BACKGROUND AND AIM: Hydronidone (HDD) is a novel pirfenidone derivative developed initially to reduce hepatotoxicity. Our previous studies in animals and humans have demonstrated that HDD treatment effectively attenuates liver fibrosis, yet the underlying mechanism remains unclear. This study aimed to investigate whether HDD exerts its anti-fibrotic effect by inducing apoptosis in activated hepatic stellate cells (aHSCs) through the endoplasmic reticulum stress (ERS)-associated mitochondrial apoptotic pathway. METHODS: The carbon tetrachloride (CCl4)- and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-induced liver fibrosis models were used for in vivo studies. In vitro studies were conducted using the human hepatic stellate cell line LX-2. The apoptotic effect of HDD on aHSCs was examined using TUNEL and flow cytometry assays. The small interfering RNA (siRNA) technique was employed to downregulate the expression of interest genes. RESULTS: HDD treatment significantly promoted apoptosis in aHSCs in both the CCl4- and DDC-induced liver fibrosis in mice and LX-2 cells. Mechanistic studies revealed that HDD triggered ERS and subsequently activated the IRE1α-ASK1-JNK pathway. Furthermore, the influx of cytochrome c from the mitochondria into the cytoplasm was increased, leading to mitochondrial dysfunction and ultimately triggering apoptosis in aHSCs. Notably, inhibition of IRE1α or ASK1 by siRNA partially abrogated the pro-apoptotic effect of HDD in aHSCs. CONCLUSIONS: The findings of both in vivo and in vitro studies suggest that HDD induces apoptosis in aHSCs via the ERS-associated mitochondrial apoptotic pathway, potentially contributing to the amelioration of liver fibrosis.

Escherichia coli Promotes Endothelial to Mesenchymal Transformation of Liver Sinusoidal Endothelial Cells and Exacerbates Nonalcoholic Fatty Liver Disease Via Its Flagellin.

BACKGROUND＆AIMS: Gut bacteria translocate into the liver through a disrupted gut vascular barrier, which is an early and common event in the development of nonalcoholic fatty liver disease (NAFLD). Liver sinusoidal endothelial cells (LSECs) are directly exposed to translocated gut microbiota in portal vein blood. Escherichia coli, a commensal gut bacterium with flagella, is markedly enriched in the gut microbiota of patients with NAFLD. However, the impact of E coli on NAFLD progression and its underlying mechanisms remains unclear. METHODS: The abundance of E coli was analyzed by using 16S ribosomal RNA sequencing in a cohort of patients with NAFLD and healthy controls. The role of E coli was assessed in NAFLD mice after 16 weeks of administration, and the features of NAFLD were evaluated. Endothelial to mesenchymal transition (EndMT) in LSECs induced by E coli was analyzed through Western blotting and immunofluorescence. RESULTS: The abundance of gut Enterobacteriaceae increased in NAFLD patients with severe fat deposition and fibrosis. Importantly, translocated E coli in the liver aggravated hepatic steatosis, inflammation, and fibrosis in NAFLD mice. Mechanistically, E coli induced EndMT in LSECs through the TLR5/MYD88/TWIST1 pathway during NAFLD development. The toll-like receptor 5 inhibitor attenuated E coli-induced EndMT in LSECs and liver injury in NAFLD mice. Interestingly, flagellin-deficient E coli promoted less EndMT in LSECs and liver injury in NAFLD mice. CONCLUSIONS: E coli promoted the development of NAFLD and promoted EndMT in LSECs through toll-like receptor 5/nuclear factor kappa B-dependent activation of TWIST1 mediated by flagellin. Therapeutic interventions targeting E coli and/or flagellin may represent a promising candidate for NAFLD treatment.

Hydronidone ameliorates liver fibrosis by inhibiting activation of hepatic stellate cells via Smad7-mediated degradation of TGFßRI.

BACKGROUND AND PURPOSE: Liver fibrosis is a wound-healing reaction that eventually leads to cirrhosis. Hydronidone is a new pyridine derivative with the potential to treat liver fibrosis. In this study, we explored the antifibrotic effects of hydronidone and its potential mode of action. METHODS: The anti-hepatic fibrosis effects of hydronidone were studied in carbon tetrachloride (CCl4 )- and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)- induced animal liver fibrosis. The antifibrotic mechanisms of hydronidone were investigated in hepatic stellate cells (HSCs). The antifibrotic effect of hydronidone was further tested after Smad7 knockdown in HSCs in mouse models of fibrosis. RESULTS: In animal models, hydronidone attenuated liver damage and collagen accumulation, and reduced the expression of fibrosis-related genes. Hydronidone decreased the expression of fibrotic genes in HSCs. Impressively, hydronidone significantly upregulated Smad7 expression and promoted the degradation of transforming growth factor ß receptor I (TGFßRI) in HSCs and thus inhibited the TGFß-Smad signalling pathway. Specific knockdown of Smad7 in HSCs in vivo blocked the antifibrotic effect of hydronidone. CONCLUSION: Hydronidone ameliorates liver fibrosis by inhibiting HSCs activation via Smad7-mediated TGFßRI degradation. Hydronidone is a potential drug candidate for the treatment of liver fibrosis.

FABP4 in LSECs promotes CXCL10-mediated macrophage recruitment and M1 polarization during NAFLD progression.

BACKGROUND AND AIMS: Non-alcoholic liver disease (NAFLD) is emerging as the leading cause of end-stage liver disease with a serious threat to global health burden. Fatty acid-binding protein 4 (FABP4) is closely associated with metabolic syndromes. We aimed to explore the potential mechanisms of FABP4 in NAFLD progression. MATERIALS AND METHODS: For NAFLD mice, animals were fed with high fat diet (HFD) for 20 weeks. The assays of hematoxylin and eosin, Sirius Red, oil red O staining and immunohistology were performed to evaluate hepatic pathology. Flow cytometric analysis was used to distinguish macrophage subtypes. RESULTS: Serum FABP4 level was positively correlate with the severity of hepatic steatosis in NAFLD patients. FABP4 expression was mainly distributed in liver sinusoidal endothelial cells (LSECs), which was significantly increased in HFD mice. The level of CXCL10 was positively correlated with FABP4 at mRNA and serum level. FABP4 inhibition resulted in decreased expression of CXCL10. The percentage of M1 macrophage and CXCR3+ cells in infiltrated macrophage was increased in liver of HFD mice. Inhibition of FABP4 ameliorated HFD-induced M1 macrophage polarization as well as CXCR3+ macrophages recruitment. Recombinant CXCL10 and co-culturing with TMNK-1 stimulated macrophage toward M1 polarization, which could be reversed by CXCR3 inhibitor. Palmitic acid treatment resulted in increased nuclear P65 expression, which could be reversed by inhibiting FABP4. Cxcl10 expression was dramatically suppressed by NF-κB inhibitor. CONCLUSIONS: FABP4 in LSECs may play a pathogenic role in NAFLD course by promoting CXCL10-mediated macrophage M1 polarization and CXCR3+ macrophage infiltration via activating NF-κB/p65 signaling.

Application of Metal-Free Dearomatization Reaction as a Sustainable Strategy to Direct Access Complex Cyclic Compounds.

The highly efficient construction of complicated heterocyclic frameworks in an atom- and step-economic manner is still one of the cores of synthetic chemistry. Dearomatization reactions show the unique advantage for the construction of functionalized heterocycles and have attracted widespread attention over the past two decades. The metal-free approach has proved to be a green and sustainable paradigm for the synthesis of spirocyclic, polycyclic and heterocyclic scaffolds, which are widely present in natural products and bioactive molecules. In this review, the advances in the recent six years (2017-2023) in metal-free dearomatization reactions are highlighted. Emphasis is placed on developments in the field of organo-catalyzed dearomatization reactions, oxidative dearomatization reactions, Brønsted acid- or base-promoted dearomatization reactions, photoredox-catalyzed dearomatization reactions, and electrochemical oxidation dearomatization reactions.

Expansion of macrophage and liver sinusoidal endothelial cell subpopulations during non-alcoholic steatohepatitis progression.

Liver non-parenchymal cells (NPCs) play a critical role in the progression of non-alcoholic steatohepatitis (NASH). We aimed to explore the heterogeneity of NPCs and identify NASH-specific subpopulations contributing to NASH progression. Through single-cell RNA sequencing, we uncovered a proinflammatory subpopulation of Itgadhi/Fcrl5hi macrophages with potential function of modulating macrophage accumulation and promoting NASH development. We also identified subpopulations of Egr1hi and Ly6ahi liver sinusoidal endothelial cells (LSECs), which might participate in pathological angiogenesis and inflammation regulation. The Itgadhi/Fcrl5hi macrophages, Egr1hi LSECs, and Ly6ahi LSECs emerged in the early stage and expanded significantly along with pathological progression of liver injury during NASH. Cell-cell interactions between hepatic stellate cells (HSCs) and Itgadhi/Fcrl5hi macrophages, Egr1hi LSECs or Ly6ahi LSECs were enhanced in NASH liver. Our results revealed that expansion of Itgadhi/Fcrl5hi macrophages, Egr1hi LSECs or Ly6ahi LSECs was strongly associated with NASH severity, suggesting these subpopulations might be involved in NASH progression.

Simultaneous extraction and determination of alkaloids and organic acids in Uncariae Ramulas Cum Unicis by vortex-assisted matrix solid phase dispersion extraction coupled with UHPLC-MS/MS.

A simple and efficient vortex-assisted matrix solid phase dispersion with a ultra-high-performance liquid chromatography-triple quadrupole mass spectrometer (VA-MSPD-UHPLC-MS/MS) was applied for simultaneous extraction and determination of seven alkaloids and three organic acids from Uncariae Ramulas Cum Unicis. The optimal extraction conditions of the target components were obtained by Box-Behnken design (BBD) combined with response surface methodology (RSM). The results of the method validation showed that this analytical method displayed good linearity with a correlation coefficient (r) no lower than 0.9990. The recoveries of ten active ingredients from Uncariae Ramulas Cum Unicis ranged from 95.9% to 103% (RSD ≤ 2.77%). The RSDs of intra-day and inter-day precisions were all below 2.97%. The present method exhibited not only lower solvent and sample usage, but also shorter sample processing and analysis time. Consequently, the developed VA-MSPD-UHPLC-MS/MS method could be successfully and effectively used for the extraction and analysis of ten active components from Uncariae Ramulas Cum Unicis.

Intestinal Stem Cells Damaged by Deoxycholic Acid via AHR Pathway Contributes to Mucosal Barrier Dysfunction in High-Fat Feeding Mice.

High-fat exposure leads to impaired intestinal barrier function by disrupting the function of intestinal stem cells (ISCs); however, the exact mechanism of this phenomenon is still not known. We hypothesize that high concentrations of deoxycholic acid (DCA) in response to a high-fat diet (HFD) affect aryl hydrocarbon receptor (AHR) signalling in ISCs and the intestinal barrier. For this purpose, C57BL/6J mice feeding on a low-fat diet (LFD), an HFD, an HFD with the bile acid binder cholestyramine, and a LFD with the DCA were studied. We found that high-fat feeding induced an increase in faecal DCA concentrations. An HFD or DCA diet disrupted the differentiation function of ISCs by downregulating AHR signalling, which resulted in decreased goblet cells (GCs) and MUC2, and these changes were reversed by cholestyramine. In vitro experiments showed that DCA downregulated the differentiation function of ISCs, which was reversed by the AHR agonist 6-formylindolo [3,2-b]carbazole (FICZ). Mechanistically, DCA caused a reduction in indoleamine 2,3-dioxygenase 1 (IDO1) in Paneth cells, resulting in paracrine deficiency of the AHR ligand kynurenine in crypts. We demonstrated for the first time that DCA disrupts intestinal mucosal barrier function by interfering with AHR signalling in ISCs. Supplementation with AHR ligands may be a new therapeutic target for HFD-related impaired intestinal barrier function.

Loss of YB-1 alleviates liver fibrosis by suppressing epithelial-mesenchymal transition in hepatic progenitor cells.

Previously, we reported that the nuclear translocation of Y-box binding protein 1 (YB-1) is induced by transforming growth factor-ß (TGF-ß) and promotes hepatic progenitor cells (HPCs) expansion. Here, we explored the mechanisms underlying YB-1 translocation and the impact of YB-1 on the epithelial-mesenchymal transition (EMT) in HPCs. YB-1flox/floxcre+/- (YB-1f/fcre+/-) mice and YB-1f/fcre-/- mice were fed with a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) or a choline-deficient, ethionine-supplemented (CDE) diet. Liver injury and fibrosis were assessed by performing hematoxylin and eosin (HE) and Masson staining. The expression of collagen and EMT-related markers (E-cadherin, N-cadherin, and Snail) was detected by reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunofluorescence analyses. Protein kinase B (AKT) expression in HPCs was silenced via RNA interference. Nuclear YB-1 expression in HPCs was detected via western blotting and immunofluorescence analyses. HPC proliferation was detected by immunofluorescence. Our results indicate that YB-1 transcriptionally regulated the biological behavior of HPCs. HPC-specific YB-1 knockout alleviated liver fibrosis in mice fed with DDC or CDE diet. YB-1 nuclear translocation promoted matrix metallopeptidase 9 transcription. YB-1 depletion in HPCs significantly dampened the EMT and inhibited AKT phosphorylation in vitro and in vivo. AKT knockdown compromised TGF-ß-induced YB-1 nuclear translocation, thereby inhibiting the EMT and HPC proliferation. EMT and AKT were highly activated in HPCs in cirrhotic livers. Collectively, our findings indicate that the loss of YB-1 suppressed EMT in HPCs and alleviated liver fibrosis in mice, and that AKT was essential for TGF-ß-induced YB-1 nuclear translocation and HPC proliferation.

Specific knockdown of Y-box binding protein 1 in hepatic progenitor cells inhibits proliferation and alleviates liver fibrosis.

The proliferation of hepatic progenitor cells (HPCs) contributes to liver regeneration and fibrogenesis during chronic liver injury; however, the mechanism modulating HPC proliferation remains unknown. Y-box binding protein-1 (YB-1) is a transcription factor that regulates the transcription of several genes and is highly expressed in liver injury. We explored the role of YB-1 in HPC proliferation and liver fibrosis. We detected increased expansion of HPCs and elevated levels of YB-1 in HPCs from patients with hepatitis B virus-related fibrosis and choline-deficient ethionine-supplemented or 5-diethoxycarbonyl-1,4-dihydrocollidine diet-induced mice compared with those in control groups. HPC-specific deletion of YB-1 using YB-1flox/flox; Foxl1-Cre+/- mice led to reduced HPC expansion and less collagen deposition in the liver tissues compared with that in Cre-/- mice. In cultured primary HPCs, YB-1 knockdown inhibited HPC proliferation. Further experiments indicated YB-1 negatively regulated p53 expression, and silencing of p53 blocked YB-1 knockdown-mediated inhibition of HPC proliferation. Collectively, YB-1 negatively regulates HPC proliferation and alleviates liver fibrosis by p53.

Pd-Catalyzed Ring Restructuring of Oxazolidines with Alkenes Leading to Fused Polycyclic Indolizines.

A palladium-catalyzed reaction of N-propargyl oxazolidines with alkenes for the synthesis of indolizidines has been developed. Through a sequential 6-exo-dig cyclization/proton transfer/[3+2] cycloaddition/cycloreversion/aromatization process, a series of fused polycyclic indolizines are obtained in moderate to good yields with high functional group tolerance. Experimental and theoretical studies suggest that the [3+2] cycloaddition/cycloreversion of the oxazolidine ring probably involves C-C and C-O bond cleavage, providing a new ring restructuring approach for the synthesis of heterocycles.

TGF-ß/YB-1/Atg7 axis promotes the proliferation of hepatic progenitor cells and liver fibrogenesis.

Hepatic fibrosis is characterized by excessive extracellular matrix deposition and ductular reactions, manifested as the expansion of hepatic progenitor cells (HPCs). We previously reported that the Y-box binding protein 1 (YB-1) in HPCs is involved in chronic liver injury. In this study, we constructed YB-1f/f Foxl1-Cre mice and investigated the role of YB-1 in HPC expansion in murine choline-deficient, ethionine-supplemented (CDE), and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) models. Liver injury and fibrosis were measured using hematoxylin and eosin (HE), Masson, and Sirius Red staining. HPC proliferation was detected using EdU and immunofluorescence (IF). Autophagic flow was measured by mCherry-GFP-LC3B staining and transmission electron microscopy (TEM). YB-1 expression was measured by immunofluorescence and western blotting. CUT & Tag analysis, chromatin immunoprecipitation, and RT-PCR were performed to explore the regulation of autophagy-related protein 7 (Atg7) transcription by YB-1. Our results indicated that liver injury was accompanied by high expression of YB-1, proliferative HPCs, and activated autophagy in the CDE and DDC models. YB-1f/f Cre+/- mice displayed less liver injury and fibrosis than YB-1f/f Cre-/- mice in the CDE and DDC models. YB-1 promoted proliferation and autophagy of HPCs in vitro and in vivo. Transforming growth factor-ß (TGF-ß) induced YB-1 nuclear translocation and facilitated the proliferation and autophagy of HPCs. YB-1 nuclear translocation promoted the transcription of Atg7, which is essential for TGF-ß/YB-1 mediated HPCs expansion in vitro and in vivo. In summary, YB-1 nuclear translocation induced by TGF-ß in HPCs promotes the proliferation and autophagy of HPCs and Atg7 participates in YB-1-mediated HPC-expansion and liver fibrosis.

Dextran Sulfate Sodium Salt-Induced Colitis Aggravates Gut Microbiota Dysbiosis and Liver Injury in Mice With Non-alcoholic Steatohepatitis.

Objective: Inflammatory bowel disease (IBD) is characterized by gut microbiota dysbiosis, which is also frequently observed in patients with non-alcoholic fatty liver disease. Whether gut microbiota dysbiosis in IBD patients promotes the development of non-alcoholic steatohepatitis (NASH) remains unclear. We aimed to explore the role of gut microbiota dysbiosis in the development of NASH in mice with dextran sulfate sodium salt (DSS) induced colitis. Design: Dextran sulfate sodium salt was used to induce colitis, and high fat (HF), in combination with a high-fructose diet, was used to induce NASH in C57BL/6J male mice. Mice were treated with (1%) DSS to induce colitis in cycles, and each cycle consisted of 7 days of DSS administration followed by a 10-day interval. The cycles were repeated throughout the experimental period of 19 weeks. Pathological alterations in colitis and NASH were validated by hematoxylin and eosin (H&E), oil red O, Sirius red staining, and immunofluorescence. Gut microbiota was examined by 16S rRNA sequencing, and gene expression profiles of hepatic non-parenchymal cells (NPCs) were detected by RNA sequencing. Results: Dextran sulfate sodium salt administration enhanced the disruption of the gut-vascular barrier and aggravated hepatic inflammation and fibrosis in mice with NASH. DSS-induced colitis was accompanied by gut microbiota dysbiosis, characterized by alteration in the core microbiota composition. Compared with the HF group, the abundance of p_Proteobacteria and g_Bacteroides increased, while that of f_S24-7 decreased in the DSS + HF mice. Specifically, gut microbiota dysbiosis was characterized by enrichment of lipopolysaccharide producing bacteria and decreased abundance of short-chain fatty acid-producing bacteria. Gene expression analysis of liver NPCs indicated that compared with the HF group, genes related to both inflammatory response and angiocrine signaling were altered in the DSS + HF group. The expression levels of inflammation-related and vascular development genes correlated significantly with the abundance of p_Proteobacteria, g_Bacteroides, or f_S24-7 in the gut microbiota, implying that gut microbiota dysbiosis induced by DSS might aggravate hepatic inflammation and fibrosis by altering the gene expression in NPCs. Conclusion: Dextran sulfate sodium salt-induced colitis may promote the progression of liver inflammation and fibrosis by inducing microbiota dysbiosis, which triggers an inflammatory response and disrupts angiocrine signaling in liver NPCs. The abundance of gut microbiota was associated with expression levels of inflammation-related genes in liver NPCs and may serve as a potential marker for the progression of NASH.

An elevated deoxycholic acid level induced by high-fat feeding damages intestinal stem cells by reducing the ileal IL-22.

Long-term high-fat diet (HFD) destroys the intestinal mucosal barrier by damaging intestinal stem cells (ISCs). A HFD can increase the concentration of intestinal deoxycholic acid (DCA) and decrease the secretion of interleukin-22 (IL-22), which plays an important role in the proliferation, repair and regeneration of ISCs. We hypothesized that increased level of intestinal DCA induced by a HFD leads to ISC dysfunction by reducing the IL-22 levels in intestinal tissues. In this study, 2 weeks of a DCA diet or a HFD damaged ileal ISC and its proliferation and differentiation, resulting in a decrease in Paneth cells and goblet cells. Importantly, 2 weeks of a DCA diet or a HFD also reduced ileal IL-22 concentration, accompanied by a decreased number of group 3 innate lymphoid cells in ileal mucosa, which produce IL-22 after intestinal injury. Concurrent feeding with bile acid binder cholestyramine prevented all these changes induced by a HFD. In addition, in vitro study further confirmed that exogenous IL-22 reversed the decline in the proliferation and differentiation of ileal ISCs induced by DCA stimulation. Collectively, these results revealed that the decrease in intestinal IL-22 induced by DCA may be a novel mechanism by which HFD damages ISCs. The administration of IL-22 or a bile acid binder may provide novel therapeutic targets for the metabolic syndrome caused by a HFD.

Microwave-Assisted Palladium-Catalyzed Reductive Cyclization/Ring-Opening/Aromatization Cascade of Oxazolidines to Isoquinolines.

An efficient palladium-catalyzed reaction of N-propargyl oxazolidines for the construction of 4-substituted isoquinolines under microwave irradiation is developed. This transformation proceeds through a sequential palladium-catalyzed reductive cyclization/ring-opening/aromatization cascade via C-O and C-N bond cleavages of the oxazolidine ring. The practical value of this method has also been explored by conducting a millimole-scale reaction, as well as by transforming the isoquinoline into a key intermediate for the synthesis of a lamellarin analogue.

Microwave-Assisted Cu(I)-Catalyzed Synthesis of Unsymmetrical 1,4-Diamino-2-butynes via Cross-A3-Coupling/Decarboxylative A3-Coupling.

1,4-Diamino-2-butynes display both chemical and physiological properties. Here a highly efficient synthesis avenue to generate unsymmetric 1,4-diamino-2-butynes has been developed by microwave-assisted Cu(I)-catalyzed cross-A3-coupling/decarboxylative coupling of two different amines, formaldehyde, and propiolic acid through a domino process. This multicomponent reaction provides a series of target products in moderate to good yields with high chemoselectivity.

Bile acid toxicity in Paneth cells contributes to gut dysbiosis induced by high-fat feeding.

High-fat feeding (HFF) leads to gut dysbiosis through unclear mechanisms. We hypothesize that bile acids secreted in response to high-fat diets (HFDs) may act on intestinal Paneth cells, leading to gut dysbiosis. We found that HFF resulted in widespread taxonomic shifts in the bacteria of the ileal mucosa, characterized by depletion of Lactobacillus and enrichment of Akkermansia muciniphila, Clostridium XIVa, Ruminococcaceae, and Lachnospiraceae, which were prevented by the bile acid binder cholestyramine. Immunohistochemistry and in situ hybridization studies showed that G protein-coupled bile acid receptor (TGR5) expressed in Paneth cells was upregulated in the rats fed HFD or normal chow supplemented with cholic acid. This was accompanied by decreased lysozyme+ Paneth cells and α-defensin 5 and 6 and increased expression of XBP-1. Pretreatment with ER stress inhibitor 4PBA or with cholestyramine prevented these changes. Ileal explants incubated with deoxycholic acid or cholic acid caused a decrease in α-defensin 5 and 6 and an increase in XBP-1, which was prevented by TGR5 antibody or 4PBA. In conclusion, this is the first demonstration to our knowledge that TGR5 is expressed in Paneth cells. HFF resulted in increased bile acid secretion and upregulation of TGR5 expression in Paneth cells. Bile acid toxicity in Paneth cells contributes to gut dysbiosis induced by HFF.

Deoxycholic acid-stimulated macrophage-derived exosomes promote intestinal metaplasia and suppress proliferation in human gastric epithelial cells.

The crosstalk between macrophages and gastric epithelial cells has emerged as a player in chronic inflammation during intestinal metaplasia. However, the role of bile acid on this modulation remains to be studied. We hypothesized that deoxycholic acid-induced macrophages secreted exosomes to mediate intercellular communication and promoted intestinal metaplasia in human gastric epithelial cells (GES-1 cells). Macrophage-derived exosomes (M-Exos) and deoxycholic acid-induced macrophage-derived exosomes (D-Exos) were isolated by ultracentrifugation. EdU staining and CCK-8 assay were utilized to evaluate the effects of exosomes on the proliferation of GES-1 cells. Intestinal metaplasia was assessed by the expression of caudal-related homeobox transcription factor 2 (CDX2) at both mRNA and protein level. MicroRNA sequencing revealed the microRNA (miRNA) expression profiles of M-Exos and D-Exos. The role of a specific miRNA and mRNA was analyzed by using miRNA mimics, miRNA inhibitors and siRNAs. D-Exos promoted the expression of CDX2 and suppressed the proliferation of GES-1 cells, compared to M-Exos. The miRNA profiles and quantitative real-time PCR examination showed D-Exos enriched a higher level of hsa-miR-30a-5p than M-Exos. Overexpressed has-miR-30a-5p increased CDX2 expression and inhibited the proliferation in GES-1 cells via targeted Forkhead Box D1 (FOXD1), a potential regulatory factor in the process of intestinal metaplasia. D-Exos may promote intestinal metaplasia and suppress proliferation of GES-1 cells via hsa-miR-30a-5p targeting FOXD1, which may be involved in the action mechanism of bile acid on gastric mucosa.

A new exploration of white globe appearance (WGA) in ulcerative lesions.

AIM: White globe appearance (WGA), a small white lesion with a globular shape that can be clearly visualized by magnifying endoscopy with narrow-band imaging (ME-NBI), was reported to be a reliable marker of early gastric cancer (EGC). However, we found that this endoscopic presentation could also be seen in non-cancerous tissues, especially in ulcerative lesions. This study aimed to further investigate the diagnostic value of WGA in differentiating non-cancerous lesions from EGC in ulcer-type cases. MATERIALS AND METHODS: We retrospectively reviewed 54 cases of EGC and 155 cases of non-cancerous lesions in this study, all of which had endoscopic imaging data of ME-NBI scanning and pathological data of biopsy or resected specimens. The correlation of the prevalence of WGA and ulcerative lesions, as well as the characteristics of WGA between the 2 groups were analyzed in this study. RESULTS: WGA was more common in ulcerative lesions (27.6 %, 21/76) than in non-ulcerative lesions (3.8 %, 5/133) (p < 0.001) in our study. In the ulcerative cases, no significant difference in prevalence of WGA was observed between EGC and non-cancerous lesions (p = 0.532). Compared with WGA in EGC, WGA in non-cancerous lesions tended to show the characteristic of tree-branch-like vessels on globular shape (p < 0.001). CONCLUSIONS: WGA is more likely to occur in ulcerative lesions, and the presence of WGA alone cannot distinguish EGC from non-cancerous lesions in ulcer-type cases. In WGA-positive tissue, tree-branch-like vessels of globular shape may provide a certain clinical value in diagnosis of non-cancerous lesions or EGC.

Bile acids elevated by high-fat feeding induce endoplasmic reticulum stress in intestinal stem cells and contribute to mucosal barrier damage.

Long-term high-fat feeding (HF) induces intestinal mucosal barrier damage. However, the mechanism for this remains unclear. HF can elevate the intestinal and circulating bile acid (BA) levels, especially deoxycholic acid (DCA). We hypothesize that BAs elevated by HF regulate intestinal stem cell (ISC) function, which may contribute to mucosal barrier injury in the ileum of mice. In this study, we showed that 2 weeks of HF resulted in a shortening of intestinal villi and a decrease in the tight junction (TJ) protein occludin in the ileum of mice, accompanied by an increase in circulating BA levels. Importantly, 2 weeks of HF also reduced ileal ISCs and goblet cells and decreased the proliferation function of ISCs and their ability to differentiate into goblet cells. Endoplasmic reticulum (ER) stress was found to be involved in the process of ISC damage. All these alterations were reversed by cofeeding with the bile acid binder cholestyramine. In addition, the in vitro studies also confirmed a cytotoxic effect of DCA at a high concentration on ISCs and goblet cells. In conclusion, these data suggested that high levels of BAs induced by HF could impair ISC function by triggering ER stress, resulting in the disruption of the intestinal mucosal barrier.