Hepatocyte cells

Certain amino acids, like glutamine and leucine, induce an anabolic response in liver. They activate p70 ribosomal protein S6 kinase (p70S6K) and acetyl-CoA carboxylase (ACC) involved in protein and fatty acids synthesis, respectively. In contrast, the AMP-activated protein kinase (AMPK), which senses the energy state of the cell and becomes activated under metabolic stress, inactivates by phosphorylation key enzymes in biosynthetic pathways thereby conserving ATP.

9p system191 01-06-2013 50 5   Download

Liver metabolism is influenced by hormones and nutrients. Amino acids such as glutamine or leucine induce an anabolic response, which resembles that of insulin in muscle and adipose tissue. In this work, the signalling pathways and the effects of insulin were compared to those of glutamine and leucine in isolated hepatocytes from normal and streptozotocin-diabetic rats.

9p system191 01-06-2013 46 5   Download

The 5¢ flanking region of the bile salt export pump (Bsep) gene was systematically analysed to provide the basis for understanding the mechanisms which regulate Bsep transcription. In addition substrates and drugs were investigated for their ability to alter Bsep promoter activity. Bsep promoter function was restricted to hepatocyte derived HepG2 cells. The 5¢ deletional analysis revealed a biphasic shape of reporter gene activities, indicating a suppressive element between nucleotides )800 and )512. ...

9p research12 01-06-2013 38 4   Download

Hepatopoietin (HPO) is a novel human hepatotrophic growth factor. Recently, we demonstrated that the extra-cellular ligand form of HPO can stimulate proliferation of hepatic cells via its specific receptor, which is on the surface of these cells.Also, the intracellular formofHPOpotentiates the transcriptional factor AP-1. Intriguingly, a variety of HPO complexes with different molecular masses were detected in hepatocytes.

6p research12 23-04-2013 25 5   Download

The hepatocyte growth factor-regulated tyrosine kinase substrate Hrs is an early endosomal protein that is thought to play a regulatory role in the trafficking of growth factor/ receptor complexes through early endosomes. Stimulation of cells with epidermal growth factor (EGF) rapidly leads to phosphorylation of Hrs, raising the question whether the receptor tyrosine kinase phosphorylates Hrs directly. Here, we present evidence that a downstream kinase, rather than the active receptor kinase is responsible. ...

7p research12 23-04-2013 36 2   Download

Liver microsomal preparations are routinely used to predict drug interactions that can occurin vivo as a result of inhi-bition of cytochrome P450 (CYP)-mediated metabolism. However, the concentration of free drug (substrate and inhibitor)at its intrahepatic site of action, a variable that cannot be directly measured, may be significantly different from that in microsomal incubation systems.

10p tumor12 20-04-2013 47 4   Download

Post ischaemic cell calcium invasion has been described as one of the main causes of graft failure. Protective effects of calcium antagonists have been investigated but are not con-vincing and their mechanisms of action remain unclear. In this work we tested the protective effect of a new calcium inhibitor described to block a calcium current insensitive to all known calcium blockers. Specific mapacalcine receptors were first characterized on rat hepatocytesmembranes using the 125 I-labeledmapacalcine....

6p fptmusic 16-04-2013 35 3   Download

The therapeutic effect of iron (Fe) chelators on the poten-tially toxic plasma pool of nontransferrin-bound iron (NTBI), often present in Fe overload diseases and in some cancer patients during chemotherapy, is of considerable interest. In the present investigation, several multidentate pyridinones were synthesized and compared with their bidentateanalogue, deferiprone

10p fptmusic 16-04-2013 26 2   Download

Bilitranslocase is a carrier protein localized at the basolateral domain of the hepatocyte plasma membrane. It transports various organic anions, including bromosulfophthalein and anthocyanins. Functional studies in subcellular fractions enriched in plasma membrane revealed a high-affinity binding site for bilirubin, associated with bilitranslocase.

14p fptmusic 12-04-2013 38 3   Download

Diacylglycerol (DAG) andproteinkinase C(PKC) isoforms have been implicated in insulin signalling in muscle and fat cells.We evaluated the involvement ofDAGandPKCin the action of insulin in adult rat hepatocytes culturedwith dexa-methasone, but in the absence of serum, for 48 h. Our results show that although insulin stimulated glycolysis and glycogen synthesis, it had no effect on DAG mass or molecular species composition.

12p fptmusic 12-04-2013 41 3   Download

A bio-nanocapsule (BNC), composed of the surface antigen (sAg) of the hepatitis B virus, is an efficient nanomachine with which to accomplish the liver-specific delivery of genes and drugs. Approximately 110 molecules of sAg are associated to form a BNC particle with an average diameter of 130 nm. TheLprotein is an sAg peptide composed mainly of preS and S regions. The preS region, with specific affinity for human hepatocytes, is localized in the N-terminus.

10p fptmusic 11-04-2013 37 2   Download

Hepatocyte growth factor like⁄macrophage stimulating protein (HGFl⁄MSP) and hepatocyte growth factor⁄scatter factor (HGF⁄SF) define a distinct family of vertebrate-specific growth factors structurally related to the blood proteinase precursor plasminogen and with important roles in development and cancer.

9p dell39 27-03-2013 38 6   Download

Control analysis of the glycolytic flux was carried out in two fast-growth tumor cell types of human and rodent origin (HeLa and AS-30D, respect-ively). Determination of the maximal velocity (Vmax) of the 10 glycolytic enzymes from hexokinase to lactate dehydrogenase revealed that hexokin-ase (153–306 times) and phosphfructokinase-1 (PFK-1) (22–56 times) had higher over-expression in rat AS-30D hepatoma cells than in normal freshly isolated rat hepatocytes.

14p inspiron33 26-03-2013 48 5   Download

The conversion of UDP-glucuronate to glucuronate, usually thought to proceed by way of glucuronate 1-phosphate, is a site for short-term regula-tion of vitamin C synthesis by metyrapone and other xenobiotics in isola-ted rat hepatocytes [Linster CL & Van Schaftingen E (2003) J Biol Chem 278, 36328–36333].

12p inspiron33 26-03-2013 43 5   Download

Carbamoylphosphate synthetase-I is the flux-determining enzyme of the ornithine cycle, and neutralizes toxic ammonia by converting it to urea. An 80 bp glucocorticoid response unit located 6.3 kb upstream of the trans-cription start site mediates hormone responsiveness and liver-specific expression of carbamoylphosphate synthetase-I.

9p inspiron33 23-03-2013 39 3   Download

Hepatocytes located in the periportal and perivenous zones of the liver lobule show remarkable differences in the levels and activities of various enzymes and other proteins. To analyze global gene expression patterns of periportal and perivenous hepatocytes, enriched populations of the two cell types were isolated by combined collagenase⁄digitonin perfusion from mouse liver and used for microarray analysis.

11p inspiron33 23-03-2013 31 2   Download

The specific features of the plasticity of adult stem cells are largely unknown. Recently, we demonstrated the hepatic differentiation of human adipose tissue-derived mesenchymal stem cells (AT-MSCs). To identify the genes responsible for hepatic differentiation, we examined the gene expres-sion profiles of AT-MSC-derived hepatocytes (AT-MSC-Hepa) using several microarray methods.

14p media19 06-03-2013 41 1   Download

Toll-like receptors and RNA helicase family members [retinoic acid-inducible gene I (RIG-I) and melanoma differentiation associated gene-5 (MDA5)] play important roles in the induction of interferon-bas a major event in innate immune responses after virus infection. TRIF (adaptor pro-tein of Toll-like receptor 3)-mediated and Cardif (adaptor protein of RIG-I or MDA5)-mediated signaling pathways contribute rapid induction of interferon-bthrough the activation of interferon regulatory factor-3 (IRF-3)....

16p media19 04-03-2013 38 3   Download

Despite the critical importance of protein ubiquitination in the regulation of diverse cellular processes, the molecular mechanisms by which cells rec-ognize and transmit ubiquitin signals remain poorly understood. The endosomal sorting machinery component hepatocyte growth factor-regu-lated tyrosine kinase substrate (Hrs) contains a ubiquitin-interacting motif (UIM), which is believed to bind ubiquitinated membrane cargo proteins and mediate their sorting to the lysosomal degradation pathway.

14p vinaphone15 27-02-2013 41 3   Download

Macrophage-stimulating protein (MSP) is a plasma protein that circu-lates as a single-chain proform. It acquires biological activity after prote-olytic cleavage at the Arg483–Val484 bond, a process in which serum and cell surface serine proteinases have been implicated.

10p viettel02 22-02-2013 34 4   Download