Elucidation of pericholangitis and periductal fibrosis in cholestatic liver diseases via extracellular vesicles released by polarized biliary epithelial cells.

Cholestatic liver diseases causes inflammation and fibrosis around bile ducts. However, the pathological mechanism has not been elucidated. Extracellular vesicles (EVs) are released from both the basolateral and apical sides of polarized biliary epithelial cells. We aimed to investigate the possibility that EVs released from the basolateral sides of biliary epithelial cells by bile acid stimulation induce inflammatory cells and fibrosis around bile ducts, and they may be involved in the pathogenesis of cholestatic liver disease. Human biliary epithelial cells (H69) were grown on cell culture inserts and stimulated with chenodeoxycholic acid + IFN-γ. Human THP-1-derived M1-macrophages, LX-2 cells, and KMST-6 cells were treated with the extracted basolateral EVs, and inflammatory cytokines and fibrosis markers were detected by RT-PCR. Highly expressed proteins from stimulated EVs were identified, and M1-macrophages, LX-2, KMST-6 were treated with these recombinant proteins. Stimulated EVs increased the expression of TNF, IL-1ß, and IL-6 in M1-macrophages, TGF-ß in LX-2 and KMST-6 compared with the corresponding expression levels in unstimulated EVs. Nucleophosmin, nucleolin, and midkine levels were increased in EVs from stimulated cells compared with protein expression in EVs from unstimulated cells. Leukocyte cell-derived chemotaxin-2 (LECT2) is highly expressed only in EVs from stimulated cells. Stimulation of M1-macrophages with recombinant nucleophosmin, nucleolin, and midkine significantly increased the expression of inflammatory cytokines. Stimulation of LX-2 and KMST-6 with recombinant LECT2 significantly increased the expression of fibrotic markers. These results suggest that basolateral EVs are related to the development of pericholangitis and periductal fibrosis in cholestatic liver diseases.NEW & NOTEWORTHY Our research elucidated that the composition of basolateral EVs from the biliary epithelial cells changed under bile acid exposure and the basolateral EVs contained the novel inflammation-inducing proteins NPM, NCL, and MK and the fibrosis-inducing protein LECT2. We report that these new results are possible to lead to the potential therapeutic target of cholestatic liver diseases in the future.

Role of Bile-Derived Extracellular Vesicles in Hepatocellular Proliferation after Partial Hepatectomy in Rats.

Although liver regeneration has been extensively studied, the effects of bile-derived extracellular vesicles (bile EVs) on hepatocytes has not been elucidated. We examined the influence of bile EVs, collected from a rat model of 70% partial hepatectomy (PH), on hepatocytes. We produced bile-duct-cannulated rats. Bile was collected over time through an extracorporeal bile duct cannulation tube. Bile EVs were extracted via size exclusion chromatography. The number of EVs released into the bile per liver weight 12 h after PH significantly increased. Bile EVs collected 12 and 24 h post-PH, and after sham surgery (PH12-EVs, PH24-EVs, sham-EVs) were added to the rat hepatocyte cell line, and 24 h later, RNA was extracted and transcriptome analysis performed. The analysis revealed that more upregulated/downregulated genes were observed in the group with PH24-EVs. Moreover, the gene ontology (GO) analysis focusing on the cell cycle revealed an upregulation of 28 types of genes in the PH-24 group, including genes that promote cell cycle progression, compared to the sham group. PH24-EVs induced hepatocyte proliferation in a dose-dependent manner in vitro, whereas sham-Evs showed no significant difference compared to the controls. This study revealed that post-PH bile Evs promote the proliferation of the hepatocytes, and genes promoting cell cycles are upregulated in hepatocytes.

[A case of invasive intraductal papillary mucinous carcinoma arising from jejunal heterotopic pancreas].

Intraductal papillary mucinous carcinoma (IPMC) arising from the heterotopic pancreas is rare. A case of IPMC metastasis from the jejunal heterotopic pancreas was described. The heterotopic pancreas could be the source of the submucosal tumor-like lesion found in the small intestine with an elevated carbohydrate antigen (CA) 19-9 level. A 60-year-old woman was admitted to the hospital with pulmonary thromboembolism and anemia. The level of CA19-9, a tumor marker, was found to be 211.8U/ml. A tumor in the jejunum was discovered using contrast-enhanced computed tomography. There were also a number of hepatic tumors found. A submucosal tumor-like lesion in the jejunum was discovered during an enteroscopy, and a biopsy revealed it to be an adenocarcinoma. Partial resection of the jejunum was performed to control hemorrhage. Histopathology revealed an invasive IPMC arising from a heterotopic pancreas (Heinrich type II) and chemotherapy with gemcitabine and nab-paclitaxel was initiated. There have only been three cases of invasive IPMC from a heterotopic pancreas reported, and this is the first one to include chemotherapeutic treatment of distant metastasis.

[Herpes simplex encephalitis complicated with cerebral salt wasting syndrome: a case study].

A 78-year-old man was admitted to the hospital with a 4-day history of fever and confusion. Physical examination revealed oral dryness and decreased skin turgor. Blood tests showed hyponatremia (121.5 |mEq/l), and cerebrospinal fluid examination revealed positivity for herpes simplex virus 1 (HSV-1) via polymerase chain reaction. He was diagnosed with herpes simplex encephalitis and initiated acyclovir treatment. The hyponatremia was diagnosed as cerebral salt wasting syndrome (CSWS) and treated with hypertonic saline infusion and fludrocortisone. The cerebrospinal fluid HSV-1 DNA became negative, and the serum sodium levels normalized. Hyponatremia complicated with encephalitis is often caused by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), whereas CSWS is rare, mostly observed in tuberculous meningitis. Differentiating between the SIADH and CSWS is important as they require distinct therapeutic strategies.

Identification of microbial antigens in liver tissues involved in the pathogenesis of primary biliary cholangitis using 16S rRNA metagenome analysis.

BACKGROUND: Multiple factors are involved in the pathogenesis of primary biliary cholangitis (PBC), a chronic cholestatic liver disease, characterized by intrahepatic cholangiopathy. In particular, studies have suggested that environmental factors such as the presence of granulomas in the portal vein region are important for the development of PBC. This study aimed to comprehensively analyze and identify foreign-derived antigens in PBC liver tissue to confirm their involvement in PBC pathogenesis. METHODS: Portal areas and hepatocyte regions were selectively dissected from formalin-fixed paraffin-embedded PBC liver tissue samples using the microlaser method, followed by total DNA extraction. We then validated whether the bacterial strains identified through 16S rRNA metagenomic analysis were detected in PBC liver tissues. RESULTS: The most frequently detected bacterial genera in the PBC liver tissue samples were Sphingomonas panacis, Providencia, and Cutibacterium. These bacterial genera were also detected in the other PBC samples. Validation for the detection of S. panacis, the most abundant genus, revealed polymerase chain reaction bands extracted from the portal areas of all samples. They were also more highly expressed than bands detected in the hepatocyte region. CONCLUSION: S. panacis antigen was specifically detected in the portal areas of PBC liver tissues. The introduction of foreign-derived antigens into the liver as an environmental factor could be a possible mechanism for the development of PBC.