0000000000937484
AUTHOR
Gaetano Magro
Beta-2-glycoprotein I is growth regulated and plays a role as survival factor for hepatocytes
Beta-2-glycoprotein I (beta(2)GPI) is mainly produced by the liver and is found in plasma partially associated to lipoproteins. Although various properties have been attributed to this protein, its physiological role remains still unclear. We investigated its expression in cultured liver cells and in regenerating liver. Expression studies in HepG2 cells demonstrate that beta(2)GPI mRNA is regulated in a cell cycle-dependent manner, with very low expression in low cycling conditions and increasing levels in proliferating cells. p21 WAF-dependent growth arrest, induced by butyrate treatment, down-regulate beta(2)GPI mRNA levels. Immunolocalization in normal rat liver shows a non-homogeneous p…
Liver is not the unique site of synthesis of beta 2-glycoprotein I (apolipoprotein H): evidence for an intestinal localization.
Apolipoprotein H is a protein of about 50 kilodaltons, structurally related to the regulators of the complement activation family. Its physiological function is poorly understood but it has been implicated in lipid metabolism and coagulative pathways. The major site of synthesis is thought to be the liver. Several reports indicate that apolipoprotein H is the antigen of the antiphospholipid antibodies and also behaves as an acute-phase reactant. Moreover, 40% of plasma apolipoprotein H is associated with very low-density lipoprotein, high-density lipoprotein, and postprandial chylomicrons. In this study we investigated other sites of synthesis by reverse transcription/polymerase chain react…