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Background & Aims: A single point mutation in the Z-variant of alpha 1-antitrypsin (Z-AAT) alone can lead to both a protein folding and trafficking defect, preventing its exit from the endoplasmic reticulum (ER), and the formation of aggregates that are retained as inclusions within the ER of hepatocytes. These defects result in a systemic AAT deficiency (AATD) that causes lung disease, whereas the ER-retained aggregates can induce severe liver injury in patients with ZZ-AATD. Unfortunately, therapeutic approaches are still limited and liver transplantation represents the only curative treatment option . To overcome this limitation, a better understanding of the molecular basis of ER aggregate formation could provide new strategies for therapeutic intervention., Methods: Our functional and omics approaches here based on human hepatocytes from patients with ZZ-AATD have enabled the identification and characterisation of the role of the protein disulfide isomerase (PDI) A4/ERP72 in features of AATD-mediated liver disease., Results: We report that 4 members of the PDI family (PDIA4, PDIA3, P4HB, and TXNDC5) are specifically upregulated in ZZ-AATD liver samples from adult patients. Furthermore, we show that only PDIA4 knockdown or alteration of its activity by cysteamine treatment can promote Z-AAT secretion and lead to a marked decrease in Z aggregates. Finally, detailed analysis of the Z-AAT interactome shows that PDIA4 silencing provides a more conducive environment for folding of the Z mutant, accompanied by reduction of Z-AAT-mediated oxidative stress, a feature of AATD-mediated liver disease., Conclusions: PDIA4 is involved in AATD-mediated liver disease and thus represents a therapeutic target for inhibition by drugs such as cysteamine. PDI inhibition therefore represents a potential therapeutic approach for treatment of AATD., Lay Summary: Protein disulfide isomerase (PDI) family members, and particularly PDIA4, are upregulated and involved in alpha 1-antitrypsin deficiency (AATD)-mediated liver disease in adults. PDI inhibition upon cysteamine treatment leads to improvements in features of AATD and hence represents a therapeutic approach for treatment of AATD-mediated liver disease., Competing Interests: The authors have no potential conflicts (financial, professional, or personal) relevant to the manuscript. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2021 The Authors.)

Purpose: Gastric carcinomas are heterogeneous, and the current therapy remains essentially based on surgery with conventional chemotherapy and radiotherapy. This study aimed to characterize biomarkers allowing the detection of cancer stem cells (CSC) in human gastric carcinoma of different histologic types. Experimental Design: The primary tumors from 37 patients with intestinal- or diffuse-type noncardia gastric carcinoma were studied, and patient-derived tumor xenograft (PDX) models in immunodeficient mice were developed. The expressions of 10 putative cell surface markers of CSCs, as well as aldehyde dehydrogenase (ALDH) activity, were studied, and the tumorigenic properties of cells were evaluated by in vitro tumorsphere assays and in vivo xenografts by limiting dilution assays. Results: We found that a subpopulation of gastric carcinoma cells expressing EPCAM, CD133, CD166, CD44, and a high ALDH activity presented the properties to generate new heterogeneous tumorspheres in vitro and tumors in vivo CD44 and CD166 were coexpressed, representing 6.1% to 37.5% of the cells; ALDH activity was detected in 1.6% to 15.4% of the cells; and the ALDH + cells represented a core within the CD44 + /CD166 + subpopulation that contained the highest frequency of tumorigenic CSCs in vivo The ALDH + cells possessed drug efflux properties and were more resistant to standard chemotherapy than the ALDH - cells, a process that was partially reversed by verapamil treatment. Conclusions: CD44 and ALDH are the most specific biomarkers to detect and isolate tumorigenic and chemoresistant gastric CSCs in noncardia gastric carcinomas independently of the histologic classification of the tumor. Clin Cancer Res; 23(6); 1586-97. ©2016 AACR ., (©2016 American Association for Cancer Research.)

Background & Aims: Studies in animal models have shown that bone marrow-derived cells (BMDC) could be involved in the formation of carcinomas of the upper gastrointestinal tract, including gastric carcinoma. Most gastric carcinomas in humans have been associated with chronic infection with Helicobacter pylori; we investigated the bacteria's potential to induce premalignant lesions in mice and studied the kinetics of BMDC settlement in the gastric epithelium., Methods: C57BL/6J female chimeric mice with BMDCs from male donors that express green fluorescent protein were infected with human-derived and mouse-adapted strains of H pylori and followed. We assessed development of pathologic features and recruitment of BMDC to the gastric mucosa using immunohistochemistry and fluorescent in situ hybridization analyses of gastric tissue sections., Results: Infection of mice with different strains of H pylori led to the development of chronic inflammation, hyperplasia, and mucinous metaplasia, and, later in life, of pseudointestinal metaplasia and dysplasia. After 1 year, gastric glands that contained green fluorescent protein-positive male cells were detected in 50%-90% of female chimeric mice infected with H pylori strains; the presence of these glands correlated with the development of pseudointestinal metaplasia. Twenty-two percent of H pylori-induced dysplastic lesions were composed of glands that contained epithelial BMDCs., Conclusions: H pylori infection leads to development of chronic inflammation, hyperplasia, metaplasia, and dysplasia, as well as the recruitment and accumulation of BMDC in the gastric epithelial mucosa. Nearly 25% of dysplastic lesions include cells that originate from the BM., (Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Thrombin, acting via protease-activated receptors (PARs), and tissue factor (TF) are involved in inflammation, tissue repair and tumorigenesis. Hepatocellular carcinomas (HCCs) usually complicate chronic liver diseases characterised by inflammation and fibrosis. The aim of this study was to describe the expression of PARs and TF in normal liver, cirrhosis and HCCs. We performed an immunohistochemical detection of PAR-1, PAR-3, PAR-4 and human TF in human tissue samples from 19 subnormal livers, 33 cirrhosis and 30 HCCs. PAR-1 was found on endothelial cells of sinusoids and larger vessels. In cirrhosis, spindle-shaped cells within septa and T lymphocytes were PAR-1 positive. A few PAR-1-positive tumour cells were found in 10% of HCCs. PAR-4 expression was restricted to macrophages, B lymphocytes and nerves. PAR-3 expression was rare. Unexpectedly, TF was expressed in 95% of normal livers and in 94% of cirrhosis but only in 50% of HCCs (p<0.001). Staining was mostly hepatocellular. No association existed between TF labelling and clinicopathological characteristics of HCCs. In conclusion, the pattern of expression of PARs is compatible with its role in chronic liver disease by promoting inflammation via immune cells and neurogenic stimulation. However, our data do not support a role for PARs or TF in HCC progression.

BACKGROUND: The cytokine leukemia inhibitory factor (LIF) mediates its biological effects through binding to its high affinity receptor made of the low-affinity LIF receptor subunit gp190 (LIF-R) and the gp130 subunit. LIF exerts several important effects in the liver, however, data on liver expression of LIF are scarce. The aim of this study was to examine the expression of LIF and LIF-R in human liver. RESULTS: LIF expression, analyzed by immunohistochemistry, was barely detectable in normal liver but was strong within cirrhotic fibrous septa and was found in spindle-shaped cells compatible with myofibroblasts. Accordingly, cultured human liver myofibroblasts expressed high levels of LIF as shown by ELISA and Northern blot. Biological assay demonstrated that myofibroblast-derived LIF was fully active. RT-PCR showed expression of the LIF-D and M isoforms, and also of low levels of new variants of LIF-D and LIF-M resulting from deletion of exon 2 through alternative splicing. LIF receptor expression was detected mainly as a continuous sinusoidal staining that was enhanced in cirrhotic liver, suggestive of endothelial cell and/or hepatocyte labeling. Immunohistochemistry, flow cytometry and STAT-3 phosphorylation assays did not provide evidence for LIF receptor expression by myofibroblasts themselves. LIF secretion by cultured myofibroblasts was down regulated by the addition of interleukin-4. CONCLUSIONS: We show for the first time the expression of LIF in human liver myofibroblasts, as well as of two new isoforms of LIF mRNA. Expression of LIF by myofibroblasts and of its receptor by adjacent cells suggests a potential LIF paracrine loop in human liver that may play a role in the regulation of intra-hepatic inflammation.

Background/aim: Several lines of evidence incriminate the serine proteinase thrombin in liver fibrogenesis either through its procoagulant function or its signaling via cell-surface receptors. The aim of this study was therefore to evaluate the effect of thrombin inhibition on experimental liver fibrosis., Methods: Fibrosis was induced in rats by administration of CCl4 for either three or seven weeks. Oral administration of the thrombin antagonist SSR182289 started one week after the start of CCl4 intoxication. Fibrosis and the area occupied by alpha smooth muscle actin (ASMA) positive cells were quantified with histomorphometry. Expression of fibrosis related genes was measured by real time RT-PCR., Results: After three weeks of CCl4, treatment with SSR182289 did not significantly decrease the area of fibrosis but significantly decreased the area of ASMA positive cells by 22% (p = 0.03) and the expression of TIMP-1 mRNA by 52% (p = 0.02). There was no effect on gene expression of collagen I, MMP-2, or TIMP-2. After seven weeks of CCl4, treatment with SSR182289 resulted in a significant decrease in fibrosis (-30%, p = 0.04) and ASMA positive areas (-35%, p = 0.05). SSR182289 alone had no effect on the measured parameters. Additionally, it did not alleviate the acute toxicity of CCl4 as shown by measuring levels of serum aminotransferases and the area of necrosis., Conclusions: These data provide evidence that thrombin antagonism can reduce liver fibrogenesis. The early effect of SSR182289 on ASMA and TIMP-1 expression suggests that it is beneficial in reducing fibrogenic cell activation.