Increased type II transforming growth factor-beta receptor expression in liver cells during cholesterol challenge

Expression and Function of BMP and Activin Membrane-Bound Inhibitor (BAMBI) in Chronic Liver Diseases and Hepatocellular Carcinoma

BAMBI (bone morphogenetic protein and activin membrane-bound inhibitor) is a transmembrane pseudoreceptor structurally related to transforming growth factor (TGF)-β type 1 receptors (TGF-β1Rs). BAMBI lacks a kinase domain and functions as a TGF-β1R antagonist. Essential processes such as cell differentiation and proliferation are regulated by TGF-β1R signaling. TGF-β is the best-studied ligand of TGF-βRs and has an eminent role in inflammation and fibrogenesis. Liver fibrosis is the end stage of almost all chronic liver diseases, such as non-alcoholic fatty liver disease, and at the moment, there is no effective anti-fibrotic therapy available. Hepatic BAMBI is downregulated in rodent models of liver injury and in the fibrotic liver of patients, suggesting that low BAMBI has a role in liver fibrosis. Experimental evidence convincingly demonstrated that BAMBI overexpression is able to protect against liver fibrosis. Chronic liver diseases have a high risk of hepatocellular carcinoma (HCC), and BAMBI was shown to exert tumor-promoting as well as tumor-protective functions. This review article aims to summarize relevant studies on hepatic BAMBI expression and its role in chronic liver diseases and HCC.

Effect of Phosphatidylcholine Nanosomes on Phospholipid Composition of the Plasma Membranes in Liver Cells and Blood Serum in Experimental Atherosclerosis

Alimentary atherosclerosis is associated with a significant decrease in the content of phosphatidylcholine, the phospholipid that provides antioxidant protection, in the plasma membrane of liver cells, while the level of phosphatidic acid that initiates generation of superoxides, on the contrary, increases. The level of membrane phosphatidylserine, a target of the scavenger receptors, which initiates removal of damaged cells and modified lipoproteins from the circulation was also elevated. In the blood serum of rabbits receiving an atherogenic diet, the content of cardiolipin involved in the immune mechanisms of atherosclerosis development and a risk factor for thrombosis, sharply increased. The level of lysophosphatidylcholine that mediates initiation and progression of atherosclerosis increased. The content of phosphatidylinositol that is involved in the mechanisms protecting from exposure to excess cholesterol was significantly reduced. Treatment of alimentary atherosclerosis with "empty" phosphatidylcholine nanosomes eliminates the key factors initiating atherosclerosis development.