Calcium ; metabolism ; Hepatocytes ; metabolism ; Homeostasis ; Humans

Animals ; Hepatocytes ; metabolism ; Humans ; Lipoproteins ; metabolism ; Protein Binding ; Proteins ; metabolism

Hepatocytes ; metabolism ; pathology ; Liver Diseases ; genetics ; metabolism ; pathology

Carcinoma, Hepatocellular ; metabolism ; pathology ; Hepatocytes ; metabolism ; pathology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; NF-kappa B ; metabolism

Aquaporin-9 (AQP9) is a membrane-span transport protein expressed in the liver. It is located in the cytoplasm membrane of hepatic cells. In addition to water, it is also permeable to glycerol, urea, and other small solutes. Several evidences have revealed that AQP9 is involved in multiple physiological and pathological process of the liver. This paper summarized the expression of AQP9 in the liver and the effect on the physiological and pathological processes of the liver. AQP9 may be defined as a novel target for diagnosis and treatment of hepatic diseases.
Aquaporins ; metabolism ; Cell Membrane ; metabolism ; Glycerol ; Hepatocytes ; metabolism ; Humans ; Liver ; metabolism ; Urea

Primary human hepatocytes (PHH) are the gold standard of in vitro human liver model for drug screening. However, a problem of culturing PHH in vitro is the rapid decline of cytochrome P450 (CYP450) activity, which plays an important role in drug metabolism. In this study, thermo-responsive culture dishes were used to explore the conditions for murine embryonic 3T3-J2 fibroblasts to form cell sheet. Based on the cell sheet engineering technology, a three-dimensional (3D) "sandwich" co-culture system of 3T3-J2 cell sheet/PHH/collagen gel was constructed. The tissue structure and protein expression of the model section were observed by hematoxylin eosin staining and immunofluorescence staining respectively. Phenacetin and bupropion were used as substrates to determine the activity of CYP450. The contents of albumin and urea in the system were determined by enzyme linked immunosorbent assay (ELISA). The results showed that the complete 3T3-J2 cell sheet could be obtained when the cell seeding density was 1.5×10⁶ /dish (35 mm dish) and the incubation time at low temperature was 60 min. Through cell sheet stacking, a 3D in vitro liver model was developed. Compared with the two-dimensional (2D) model, in the 3D model, the cell-cell and cell-matrix connections were tighter, the activities of cytochrome P450 CYP1A2 and cytochrome P450 CYP2B6 were significantly increased, and the secretion levels of albumin and urea were increased. These indexes could be maintained stably for 21 d. Therefore, cell sheet stacking is helpful to improve the level of liver function of 3D liver model. This model is expected to be used to predict the metabolism of low-clearance drugs in preclinical, which is of great significance for drug evaluation and other studies.
Albumins/metabolism* ; Animals ; Cytochrome P-450 Enzyme System/metabolism* ; Hepatocytes/metabolism* ; Humans ; Liver ; Mice ; Urea/metabolism*

OBJECTIVETo investigate the characteristics of the intra- and extra-hepatocyte sodium ions distribution in scalded rats during early postburn stage,with the aim of improving burn shock resuscitation regime and the resuscitation effects.

METHODSAdult Sprague-Dawley rats were randomly divided into sham scalding (C, n = 12) and scalding (S, n = 7) groups. The rats in S group were subjected to 40% TBSA III degree scalding on the back and were catheterized via jugular vein for fluid resuscitation. The rats in C group were catheterized via jugular vein without fluid infusion and were sham scalded by warm water in temperature of 37 degrees. The changes in the intra- and extra-hepatocyte sodium ion contents were determined in vivo by (23)Na-magnetic resonance spectrum technology, while the existing state of the intra- and extra-hepatocyte sodium ion was determined by detecting (23)Na-magnetic resonance horizontal delaying time (T(2)).

RESULTSThe extra-hepatocyte sodium content in S group at 24 postburn hours (PBHs) was 17% less than that in C group. In addition, the T(2f) (fast T(2)) in S group remained stable but maintained a higher ratio during the observation time. This suggested that the sodium binding sites in extra-hepatocyte matrix increased relatively and that intra-hepatocyte sodium content increased by 57%. But the T(2) and the fast and slow parts of the T(2) kept stable, which implied that intra-hepatocyte catabolizing products were increased. This led to an increase in the sodium ion binding sites within intra-hepatocyte matrix in proportion to the sodium ion content.

CONCLUSIONDuring early postburn stage, the extra-hepatocyte sodium in a remote organ such as the liver exhibited relative deficiency due to its ingress into hepatocyte cytoplasm and to the increase of sodium combining sites.

Animals ; Binding Sites ; Burns ; metabolism ; Hepatocytes ; metabolism ; Magnetic Resonance Spectroscopy ; Rats ; Rats, Sprague-Dawley ; Sodium ; metabolism

OBJECTIVETo determine the effect of intermittent hypoxia on lipid metabolism in liver cells and to explore the possible molecular pathways involved in this process.

METHODSAn intermittent hypoxia cell model system was established by incubating the human hepatic cell lines L02 and HepG2 in an atmosphere of 2% O₂, 5% CO₂ and 93% N₂ for 8 hours per day over a period of 1, 2, 3, 4 or 5 days. Cells cultured in normoxia conditions (21% O₂) served as controls. Changes in intracellular lipid droplets and triglyceride (TG) levels were assessed by biochemical assays and oil red staining. Changes in intracellular reactive oxygen species (ROS) were assessed by inverted fluorescence microscopy and flow cytometry. Changes in expression of hypoxia-inducible factor (HIF)-1a and HIF-2a proteins, and the downstream ADFP, SREBP-1c and FAS proteins, were detected by western blotting.

RESULTSFor both L02 and HepG2 cell lines, the cells grown under hypoxic conditions showed significantly higher lipid droplet accumulation and TG content than the cells grown under normoxic conditions (F(L02) =61.83, FHepG2 =104.19, P less than 0.01). Both oxygen concentration and time appeared to be correlated with these lipid-related changes (F(L02) =39.60, FHepG2 =76.39, P less than 0.01). The ROS fluorescence index was significantly increased after 2 days of intermittent hypoxia L02: 0.703 ± 0.129 vs. 3.310 ± 0.198, t =22.0637 and HepG2:0.617 ± 0.156 vs. 2.33 ± 0.42, t =7.2003, P < 0.05); in addition, increasing trends were observed in the ROS content and intensity of green fluorescence in conjunction with increased time of exposure to intermittent hypoxia (F(L02) =1021.84, FHepG2 =49.89, P less than 0.01). Compared with their respective control groups, the L02 and HepG2 cells both showed significantly upregulated expression of HIF-1a ADFP, SREBP-1c and FAS (L02:FHIF-1a =371.19, FsREBP-1c =204.49, FFAS =38.20, FADFP =154.31, P less than 0.05 and HepG2:FHF-1a =150.84, FSRERBP-1c =107.35, FFAs =279.71, FADFP =352.06, P less than 0.01). In contrast, the HIF-2a level was markedly decreased in the cells after 4 and 5 days of exposure to intermittent hypoxia (F(L02) =125.29, FHcpG2 =10.68, P less than 0.05).

CONCLUSIONUnder intermittent hypoxic conditions, ROS may regulate the expression of hypoxia-inducible factors and the adipose differentiation-related protein,as well as influence fatty acid metabolism via a HIF-1 a-SREBP-1 c-FAS signal and upregulation of the ADFP protein, in liver cells.

Cell Hypoxia ; Cell Line ; Hep G2 Cells ; Hepatocytes ; metabolism ; Humans ; Lipid Metabolism ; Reactive Oxygen Species ; metabolism

Acetaminophen ; metabolism ; Animals ; Cells, Cultured ; Drug Interactions ; Flavonoids ; metabolism ; Hepatocytes ; metabolism ; Humans

OBJECTIVESTo study the dynamic change of hepatic oval cells (HOC) in the process of rat liver cirrhosis formation induced by dimethylnitrosamine (DMN), and to explore its pathophysiology significance.

METHODSA rat cirrhosis model was established by using DMN. Microscopical and electronmicroscopical changes of HOC were examined. Thy1.1 was detected by immunohistochemical method at different times. The ratio of HOC was checked using image pattern analysis and Western blot. The number of HOC was counted microscopically.

RESULTSAt the 4th week after DMN administration, the liver fibrosis was at its peak, with false lobules formation combined with large areas of hemorrhage and necrosis. The fibrosis started to minimize at the 6th week, and also the inflammatory changes at the 8th week. Thy1.1 positive stained cells dispersed at the 2nd week; increased at the 4th week around fiber septa; reached its peak at the 6th week, then decreased at the 8th week. The results of image pattern analysis, cell counting under light microscope and Western blot were constant, with the highest cell numbers at the 6th week, and dropped at the 8th week. The ultrastructure of HOC was characterized by their small sized, oval nuclei, and higher nucleus/plasma ratio.

CONCLUSIONDuring the formation and reduction of rat cirrhosis caused by DMN, Thy1.1 stained HOC showed notable dynamic change, which may play an important role in the cirrhotic process.

Animals ; Dimethylnitrosamine ; Hepatocytes ; metabolism ; Liver Cirrhosis, Experimental ; metabolism ; Male ; Rats ; Rats, Wistar ; Thy-1 Antigens ; metabolism