transforming-growth-factor-beta and Hepatitis--Alcoholic

Topics: Animals; Ataxia Telangiectasia Mutated Proteins; Cell Cycle Checkpoints; Cyclin-Dependent Kinase Inhibitor p15; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Hepatitis, Alcoholic; Humans; Liver Regeneration; Mice; Transforming Growth Factor beta; Tumor Suppressor Protein p53; Up-Regulation

Activation of TGFB (transforming growth factor β) promotes liver fibrosis by activating hepatic stellate cells (HSCs), but the mechanisms of TGFB activation are not clear. We investigated the role of ECM1 (extracellular matrix protein 1), which interacts with extracellular and structural proteins, in TGFB activation in mouse livers.. We performed studies with C57BL/6J mice (controls), ECM1-knockout (ECM1-KO) mice, and mice with hepatocyte-specific knockout of EMC1 (ECM1. ECM1-KO mice spontaneously developed liver fibrosis and died by 2 months of age without significant hepatocyte damage or inflammation. In liver tissues of mice, we found that ECM1 stabilized extracellular matrix-deposited TGFB in its inactive form by interacting with αv integrins to prevent activation of HSCs. In liver tissues from patients and in mice with CCl. ECM1, produced by hepatocytes, inhibits activation of TGFB and its activation of HSCs to prevent fibrogenesis in mouse liver. Strategies to increase levels of ECM1 in liver might be developed for treatment of fibrosis.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Extracellular Matrix Proteins; Hepatic Stellate Cells; Hepatitis, Alcoholic; Hepatitis, Viral, Human; Humans; Liver; Liver Cirrhosis, Alcoholic; Liver Cirrhosis, Experimental; Male; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Signal Transduction; Transforming Growth Factor beta

Membrane-coated extracellular vesicles (EVs) released by cells can serve as vehicles for delivery of biological materials and signals. Recently, we demonstrated that alcohol-treated hepatocytes cross-talk with immune cells via exosomes containing microRNA (miRNAs). Here, we hypothesized that alcohol-exposed monocytes can communicate with naive monocytes via EVs. We observed increased numbers of EVs, mostly exosomes, secreted by primary human monocytes and THP-1 monocytic cells in the presence of alcohol in a concentration- and time-dependent manner. EVs derived from alcohol-treated monocytes stimulated naive monocytes to polarize into M2 macrophages as indicated by increased surface expression of CD68 (macrophage marker), M2 markers (CD206 (mannose receptor) and CD163 (scavenger receptor)), secretion of IL-10, and TGFβ and increased phagocytic activity. miRNA profiling of the EVs derived from alcohol-treated THP-1 monocytes revealed high expression of the M2-polarizing miRNA, miR-27a. Treatment of naive monocytes with control EVs overexpressing miR-27a reproduced the effect of EVs from alcohol-treated monocytes on naive monocytes and induced M2 polarization, suggesting that the effect of alcohol EVs was mediated by miR-27a. We found that miR-27a modulated the process of phagocytosis by targeting CD206 expression on monocytes. Importantly, analysis of circulating EVs from plasma of alcoholic hepatitis patients revealed increased numbers of EVs that contained high levels of miR-27a as compared with healthy controls. Our results demonstrate the following: first, alcohol increases EV production in monocytes; second, alcohol-exposed monocytes communicate with naive monocytes via EVs; and third, miR-27a cargo in monocyte-derived EVs can program naive monocytes to polarize into M2 macrophages.

Topics: Cell Differentiation; Cell Line; Cell Polarity; Ethanol; Extracellular Vesicles; Hepatitis, Alcoholic; Humans; Interleukin-10; Lectins, C-Type; Macrophages; Mannose Receptor; Mannose-Binding Lectins; MicroRNAs; Monocytes; Phagocytosis; Phenotype; Receptors, Cell Surface; RNA Transport; Time Factors; Transforming Growth Factor beta