Differential Contributions of Fibroblast Subpopulations to Intercellular Communication in Eosinophilic Esophagitis.

Fibroblast heterogeneity remains undefined in eosinophilic esophagitis (EoE), an allergic inflammatory disorder complicated by fibrosis. We utilized publicly available single-cell RNA sequencing data (GSE201153) of EoE esophageal biopsies to identify fibroblast sub-populations, related transcriptomes, disease status-specific pathways and cell-cell interactions. IL13-treated fibroblast cultures were used to model active disease. At least 2 fibroblast populations were identified, F_A and F_B. Several genes including ACTA2 were more enriched in F_A. F_B percentage was greater than F_A and epithelial-mesenchymal transition upregulated in F_B vs. F_A in active and remission EoE. Epithelial-mesenchymal transition was also upregulated in F_B in active vs. remission EoE and TNF-α signaling via NFKB was downregulated in F_A. IL-13 treatment upregulated ECM-related genes more profoundly in ACTA2- fibroblasts than ACTA2+ myofibroblasts. After proliferating epithelial cells, F_B and F_A contributed most to cell-cell communication networks. ECM-Receptor interaction strength was stronger than secreted or cell-cell contact signaling in active vs. remission EoE and significant ligand-receptor pairs were driven mostly by F_B. This unbiased analysis identifies at least 2 fibroblast sub-populations in EoE in vivo, distinguished in part by ACTA2. Fibroblasts play a critical role in cell-cell interactions in EoE, most profoundly via ECM-receptor signaling via the F_B sub-group.

Direct and indirect effects of alcohol and its toxic metabolite acetaldehyde on human esophageal myofibroblasts and epithelial cells.

BACKGROUND: Mechanisms by which alcohol increases the risk of esophageal squamous cell carcinoma remain undefined. Human esophageal myofibroblasts (HEMFs) subjacent to the squamous epithelium are exposed directly to these agents via epithelial barrier defects and indirectly via factors derived from the exposed epithelium. Our aim was to investigate the cellular biology of HEMFs and HEMF-esophageal epithelial cell interactions in response to alcohol and its toxic metabolite acetaldehyde. METHODS: An immortalized HEMF and a human esophageal epithelial cell line (Epi) were treated with alcohol (0 to 200 mM) or acetaldehyde (0 to 100 µM) in a cyclic fashion or incubated with supernatants collected from treated cells. Healthy cell %, reactive oxygen species (ROS), and proliferation were assessed via flow cytometry, luminescence, scratch wound, and colorimetric assays, respectively. A 15-plex multiplex assay was performed on cell supernatants, followed by IL-6 and IL-8 qRT-PCR and ELISA. RESULTS: Healthy HEMF decreased to less than 80% at 30 mM alcohol and 70 µM acetaldehyde, with microscopic changes at 40 µM acetaldehyde. HEMF ROS was detected at 100 mM alcohol and 80 µM acetaldehyde. Supernatants from 30 mM alcohol- or 40 µM acetaldehyde-treated HEMFs increased Epi proliferation more than two-fold that of lower doses. In the complementary studies, healthy Epi cells decreased to less than 80% at 50 mM and 70 µM acetaldehyde, with microscopic changes at 40 µM. Supernatants from Epi treated with 50 mM alcohol or 40 µM acetaldehyde increased HEMF proliferation more than two-fold that of lower doses. A multiplex assay of supernatants showed the greatest increase in concentrations of IL-6 and IL-8 in HEMFs and in Epi treated with higher doses of alcohol or acetaldehyde. Neutralization of IL-6 and IL-8 in supernatants of HEMFS and esophageal epithelial cells inhibited the proliferation of Epi and HEMFs, respectively. CONCLUSIONS: Alcohol and acetaldehyde doses in which the majority of HEMFs and epithelial cells are healthy, elicit the production of paracrine mediators with pro-proliferative effects on neighboring cells. Understanding the effect of alcohol and acetaldehyde on HEMFs and HEMF-epithelial interactions could help to identify the molecular basis by which alcohol increases the risk for esophageal cancer.

Inflammatory and Proliferative Pathway Activation in Human Esophageal Myofibroblasts Treated with Acidic Bile Salts.

Subepithelial human esophageal myofibroblasts (HEMFs) in gastroesophageal reflux disease (GERD) are exposed to luminal contents via impaired squamous epithelium barrier integrity. The supernatant of HEMFs treated with acidic bile salts reflective of in vivo reflux increases squamous epithelial thickness. We aimed to identify the involved mechanisms using an unbiased approach. Acidic-bile-salt-treated primary HEMF cultures (n = 4) were submitted for RNA-Seq and analyzed with Partek Flow followed by Ingenuity Pathway Analysis (IPA). A total of 1165 molecules (579 downregulated, 586 upregulated) were differentially expressed, with most top regulated molecules either extracellular or in the plasma membrane. Increases in HEMF CXCL-8, IL-6, AREG, and EREG mRNA, and protein secretion were confirmed. Top identified canonical pathways were agranulocyte and granulocyte adhesion and diapedesis, PI3K/AKT signaling, CCR5 signaling in macrophages, and the STAT3 pathway. Top diseases and biological functions were cellular growth and development, hematopoiesis, immune cell trafficking, and cell-mediated response. The targets of the top upstream regulator ErbB2 included CXCL-8, IL-6, and AREG and the inhibition of CXCL-8 in the HEMF supernatant decreased squamous epithelial proliferation. Our work shows an inflammatory/immune cell and proliferative pathways activation in HEMFs in the GERD environment and identifies CXCL-8 as a HEMF-derived chemokine with paracrine proliferative effects on squamous epithelium.

Adverse Effects of Anti-Covid-19 Drug Candidates and Alcohol on Cellular Stress Responses of Hepatocytes.

During the pandemic, dexamethasone (DEX), remdesivir (RDV), hydroxychloroquine (HCQ), thapsigargin (TG), camostat mesylate (CaM), and pralatrexate were repurposed drugs for coronavirus disease 2019 (COVID-19). However, the side effects on the liver associated with the anti-COVID therapies are unknown. Cellular stresses by these drugs at 0-30 µM were studied using HepG2, Huh7, and/or primary human hepatocytes. DEX or RDV induced endoplasmic reticulum stress with increased X-box binding protein 1 and autophagic response with increased accumulation of microtubule-associated protein 1A/1B-light chain 3 (LC3-II). DEX and RDV had additive effects on the stress responses in the liver cells, which further increased expression of activating transcription factor 4 and C/EBP homology protein 1 (CHOP), and cell death. Alcohol pretreatment (50 mM) and DEX induced greater cellular stress responses than DEX and RDV. Pralatrexate induced Golgi fragmentation, cell cycle arrest at G0/G1 phase, activations of poly (ADP-ribose) polymerase-1 (PARP) and caspases, and cell death. Pralatrexate and alcohol had synergistic effects on the cell death mediators of Bim, caspase3, and PARP. The protease inhibitor CaM and TG induced autophagic response and mitochondrial stress with altered mitochondrial membrane potential, B-cell lymphoma 2, and cytochrome C. TG and HCQ induced autophagic response markers of Unc-51 like autophagy activating kinase, LC3-II, Beclin1, and Atg5, and severe ER stress marker CHOP. Conclusion: These results suggest that the anti-COVID-19 drugs, especially with drug-drug or alcohol-drug combinations, cause cellular stress responses and injuries in the liver cells.

Ritonavir and Lopinavir Suppress RCE1 and CAAX Rab Proteins Sensitizing the Liver to Organelle Stress and Injury.

Organelle stress and Liver injuries often occur in human immunodeficiency virus (HIV) infected patients under anti-HIV therapies, yet few molecular off-targets of anti-HIV drugs have been identified in the liver. Here, we found through total RNA sequencing that the transcription of a host protease Ras converting CAAX endopeptidase 1 (RCE1) was altered in HepG2 cells treated with anti-HIV protease inhibitors, ritonavir and lopinavir. Levels of RCE1 protein were inhibited in HepG2 and primary mouse hepatocytes and in the liver of mice treated with the anti-HIV drugs, which were accompanied with inhibition of two potential substrates of RCE1, small GTP binding protein Rab13 and Rab18, which are with a common CAAX motif and known to regulate the ER-Golgi traffic or lipogenesis. Neither Rce1 transcription nor RCE1 protein level was inhibited by Brefeldin A, which is known to interfere with the ER-Golgi traffic causing Golgi stress. Knocking down Rce1 with RNA interference increased ritonavir and lopinavir-induced cell death as well as expression of Golgi stress response markers, TFE3, HSP47 and GCP60, in both primary mouse hepatocytes and mouse liver, and deteriorated alcohol-induced alanine aminotransferase (ALT) and fatty liver injury in mice. In addition, overexpressing Rab13 or Rab18 in primary human hepatocytes reduced partially the anti-HIV drugs and alcohol-induced Golgi fragmentation, Golgi stress response, and cell death injury. Conclusion: We identified a mechanism linking a host protease and its substrates, small guanosine triphosphate-binding proteins, to the anti-HIV drug-induced Golgi dysfunction, organelle stress response, and fatty liver injury.

Efficacy of ß-D-Mannuronic Acid [M2000] on the Pro-Apoptotic Process and Inflammatory-Related Molecules NFκB, IL-8 and Cd49d using Healthy Donor PBMC.

OBJECTIVE: This investigation evaluates the pro-apoptotic and anti-inflammatory effects of ß-D-mannuronic acid [M2000] compared to diclofenac, based on gene expression involved in apoptosis and inflammation process [including Bcl2, NFκB, IL-8 and Cd49d] in Peripheral Blood Mononuclear Cells [PBMCs] of healthy donors under exvivo conditions. MATERIALS: The venous blood samples of twelve healthy volunteers with aged 25-60 years were collected in heparinized tubes. The healthy volunteers were selected from no smoking group and without using illicit drugs and suffering from diabetes. The PBMCs were separated and divided into untreated and treated groups. METHODS: The PBMCs of each sample were cultured in 5 wells of culture plate, so that the first well consisted of 2×106 cells exposed by LPS-EB [1µg/ml] to stimulate PBMCs and absence of M2000 [untreated well]. The second, third, fourth and fifth wells containing 2×106 cells/well and LPS-EB, after 4 hours incubation at 37ºC, received 5, 25 and 50 µg/well of M2000 and 5 µg/well of diclofenac, respectively as treated group. RESULTS: The PBMCs were separated and RNAs were then extracted and cDNAs synthesized and gene expression levels were assessed by qRT-PCR. Furthermore, we studied whether M2000 is able to facilitate apoptosis in PBMCs. Our findings represent that the high dose of M2000 could significantly decrease the expression level of NFκB gene compared to untreated group (p < 0.0002). On the other hand, no significant change was observed in treated cells with diclofenac. All doses of M2000 could significantly augment apoptosis compared to untreated group [p < 0.0001]. Additionally, we observed the same apoptotic effects between the medium dose of M2000 and diclofenac. Besides, no significant reduction was shown in expression levels of IL8, Bcl2 and Cd49d genes in all doses of M2000 and diclofenac compared to untreated group. This experiment demonstrates M2000 as a new effective NSAID with immunosuppressive characteristics capable of stimulating apoptosis through lowering expression levels of NFκB gene, which might be probably considered as an appropriate drug for reducing the risk of developing inflammatory diseases and cancer.