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*

Adult ; Albumins ; metabolism ; Aspergillosis, Allergic Bronchopulmonary ; diagnosis ; Blood Protein Disorders ; diagnosis ; Humans ; Male

OBJECTIVETo observe the change in albumin concentration in the subeschar tissue fluid of rabbits in early stage after burn, and to analyze its regular pattern.

METHODSThirty-four adult male New Zealand rabbits were divided into control group and experiment group according to the random number table, with 17 rabbits in each group. Rabbits in experiment group were subjected to 8% TBSA full-thickness scald on the back and were injected with human serum albumin in subeschar tissue serving as tracing albumin. 1.5 mL blood sample was collected at post scald hour (PSH) 2, 4, 8, 16, 24, 48, 72 respectively. Rabbits in control group were dealt with the above-mentioned procedures except for scald. The concentration of tracing albumin was measured with the enzyme-linked immunosorbent assay kit. The concentration of the serum albumin of rabbits were determined with biochemical analyzer. Pharmacokinetics parameters of tracing albumin were calculated with fitting model of 3P97 practical pharmacokinetics calculating program.

RESULTS(1) Concentration of tracing albumin of rabbits in experiment group was respectively higher than that in control group (P < 0.01) at each time point, and it peaked at PSH 8 [(421 +/- 10) microg/L]. (2) The concentration of serum albumin of rabbits in experiment group decreased in the beginning and increased later, while no significant change was observed in control group. (3) The distribution phase half-life of tracing albumin of rabbits in experiment group (4.0271 h) was about 1/3 of that of the control group (12.0907 h); while the area under the curve in the experiment group (22 336.38 microg.h.mL(-1)) was about 4 times of that in the control group (5827.77 microg.h.mL(-1)).

CONCLUSIONSThe albumin in the subcutaneous tissue could be absorbed into blood circulation in normal conditions. The resorption occurs earlier and faster and more when obvious inflammation occurs (such as deep burn). Exudation and resorption of albumin co-exist in the early stage after burn.

Albumins ; pharmacokinetics ; therapeutic use ; Animals ; Burns ; metabolism ; therapy ; Edema ; metabolism ; Fluid Therapy ; Male ; Rabbits ; Subcutaneous Tissue ; metabolism

OBJECTIVETo investigate the change of the subfractions in existence (big and small polymers) of pulmonary surfactant (PS) and their influence on the decrease in PS activity during early postburn stage.

METHODSForty rabbits were employed in the study and were randomly divided into pre-burn, 0.5 postburn hour (PBH), 2 PBH, 6 PBH and 12 PBH groups with 8 in each group. The BALF (bronchial alveolar lavage fluid) was harvested from each rabbit. The BALF samples were centrifuged, and the supernatant (small polymer) and precipitation (big polymer) were harvested for the determination of the contents of the total phospholipids, lecithin, total protein, and albumin in both polymers.

RESULTSCompared with those in pre-burn group, the above chemical contents of PS in big polymer exhibited no change after burn (P > 0.05), but the contents of albumin and total protein increased obviously in small polymer (P < 0.01). In addition, all the contents in the small polymer increased with the elapse of time. The percentage of lecithin in total phospholipids in small polymers decreased along with the passage of time. The pre-burn contents of total phospholipids, lecithin, TP, albumin, and the percentage of lecithin in total phospholipid in small polymer were (2.23 +/- 0.40),(1.54 +/- 0.11), (16.67 +/- 1.34), (3.65 +/- 0.15) mg/ml and (77.2 +/- 3.7)%, respectively. The above indices in small polymer were (3.15 +/- 0.30), (1.77 +/- 0.08), (106.59 +/- 5.50), (11.21 +/- 0.92) mg/ml and (57.2 +/- 3.5)% respectively at 6PBH.

CONCLUSIONThe ratio of small to big polymers increased obviously, which might be an important factor in inducing the decrease in PS activity during early postburn stage leading finally to pulmonary injury.

Albumins ; analysis ; Animals ; Female ; Male ; Phosphatidylcholines ; analysis ; Phospholipids ; analysis ; Pulmonary Surfactants ; metabolism ; Rabbits ; Smoke Inhalation Injury ; metabolism

Albumins ; metabolism ; Amino Acid Sequence ; Humans ; Molecular Sequence Data ; Prostatic Secretory Proteins ; chemistry ; metabolism ; Protein Binding ; Protein Structure, Tertiary

OBJECTIVETo study albumin adduct with naphthalene metabolites, namely 1,2-naphthoquinone (1,2-NPQ) and 1,4-naphthoquinone (1,4-NPQ), as a potential biomarker for intermediate/long-term exposure to polycyclic aromatic hydrocarbons (PAH) in coke oven workers.

METHODSTwenty-eight coke oven workers and 22 control workers were recruited from a cokery. Spot urine and venous blood samples were collected from the workers after four continuously working days and personal information was obtained by questionnaire. Plasma albumin adduct was detected with gas chromatography-mass spectrometry.

RESULTSAlbumin adduct with 1,2- & 1,4-NPQ (1,2-NPQ and 1,4-NPQ), respectively, were detected in all coke oven workers and controls. Median plasma level of 1,2-NPQ-Alb in coke oven workers was significantly higher than that in controls (76.6 pmol/g vs. 44.9 pmol/g, P < 0.01). However, there was no significant difference in plasma median level of 1,4-NPQ-Alb between the two groups (48.6 pmol/g vs. 44.2 pmol/g, P > 0.05). Plasma level of 1,2-NPQ-Alb was significantly higher than that of 1,4-NPQ-Alb in coke oven workers. Urine levels of naphthalene, 1-naphthol, 2-naphthol and 1-pyrenol in coke oven workers correlated significantly with their plasma level of 1,2-NPQ-Alb (Pearson coefficient of correlation greater than 0.371, P < 0.01), but did not do significantly with 1,4-NPQ-Alb.

CONCLUSIONPlasma level of 1,2-NPQ-Alb could effectively reflect their magnitude of personal internal dose of exposure to air PAH, so it could be used as a potential biomarker to evaluate their intermediate/long-term exposure to PAH in coke oven workers.

Air Pollutants, Occupational ; adverse effects ; Albumins ; Biomarkers ; blood ; Coke ; DNA Adducts ; Humans ; Male ; Naphthalenes ; metabolism ; Naphthoquinones ; blood ; Occupational Exposure

OBJECTIVETo investigate the inhibitory effect of angiotensin-converting enzyme 2 (ACE2) on angiotensin II (Ang II)-induced down-regulation of albumin expression and enhancement of cell migration in rat hepatocytes.

METHODSCultured rat hepatocyte were treated with Ang II (10-7 mol/L) for different time lengths, and the protein expressions of vimentin and albumin and cell migration were detected. The cells transfected with lentiGFP or lentiACE2 were treated with A779 for 1 h and then with Ang II, and Western blotting and immunofluorescent cytochemistry were used to detect the protein levels; the cell migration was evaluated by Transwell assay.

RESULTAng II induced significantly increased vimentin expression and reduced albumin expression in rat hepatocytes in a time-dependent manner. Overexpression of ACE2 obviously inhibited the up-regulation of vimentin expression, reduction of albumin expression, and enhancement of cell migration induced by Ang II.

CONCLUSIONACE2 overexpression can inhibit Ang II-induced up-regulation of vimentin, reduction of albumin expression, and enhancement of cell migration in rat hepatocytes.

Albumins ; metabolism ; Angiotensin II ; pharmacology ; Animals ; Cell Movement ; Cells, Cultured ; Down-Regulation ; Hepatocytes ; cytology ; Lentivirus ; Peptidyl-Dipeptidase A ; genetics ; metabolism ; Rats ; Transfection ; Up-Regulation ; Vimentin ; metabolism

OBJECTIVETo observe the effect of parenteral nutrition (PN) with branched-chain amino acid supplementation on protein metabolism after partial hepatectomy in rats with liver cirrhosis.

METHODSEighteen rats with liver cirrhosis were randomly divided into pre-operation group (n=6), post-operation 8.5% Novamin PN group (n=6) and post-operation 10% Hepa PN group (n=6), with 6 normal rats severing as the normal control group. Five days after the operation, serum albumin (ALB), insulin-like growth factor I (IGF-1) and plasma amino acid spectrum were measured, and ALB mRNA level in the liver was assayed using RT-PCR.

RESULTSPostoperative serum ALB was similar between 10% Hepa PN and 8.5% Novamine PN groups, but the rats in the latter group showed significantly increased serum IGF-1 level, Fischer ratio and hepatic ALB mRNA expression (P<0.05).

CONCLUSIONAdministration of PN with branched-chain amino acid supplementation can ameliorate plasma amino acid spectrum and increase protein synthesis in rats with liver cirrhosis after partial hepatectomy.

Albumins ; metabolism ; Amino Acids, Branched-Chain ; administration & dosage ; therapeutic use ; Animals ; Hepatectomy ; Insulin-Like Growth Factor I ; metabolism ; Liver Cirrhosis ; therapy ; Parenteral Nutrition ; Rats ; Rats, Sprague-Dawley

BACKGROUNDIt has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes.

METHODSThe β-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed.

RESULTSThe ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P < 0.01), and ultrasonic destruction PESDA resulted in more significant gene expression than ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced β-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05).

CONCLUSIONSUltrasonic destruction of microbubbles might be a promising method for the delivery of non-viral DNA into cardiac myocytes, and the gene tranfection is related to the characteristics of microbubbles.

Albumins ; Animals ; Cell Survival ; genetics ; physiology ; Cells, Cultured ; Microbubbles ; Myocytes, Cardiac ; cytology ; metabolism ; Rats ; Rats, Wistar ; Transfection ; methods ; Ultrasonics ; methods ; beta-Galactosidase ; genetics ; metabolism

OBJECTIVETo determine the effect of albumin administration on lung injury in traumatic/hemorrhagic shock (T/HS) rats.

METHODSForty-eight adult Sprague-Dawley rats were divided into three groups randomly (n=16 in each group): Group A, Group B, Group C. In Group A, rats underwent laparotomy without shock. In Group B, rats undergoing T/HS were resuscitated with their blood plus lactated Ringer's (twice the volume of shed blood). In Group C, rats undergoing T/HS were resuscitated with their shed blood plus additional 3 ml of 5% human albumin. The expression of polymorphonuclear neutrophils CD18/CD11b in jugular vein blood was evaluated. The main lung injury indexes (the activity of myeloperoxidase and lung injury score) were measured.

RESULTSSignificant differences of the expression of CD18/11b and the severity degree of lung injury were founded between the three groups. (P<0.05). The expression of CD18/CD11b and the main lung injury indexes in Group B and Group C increased significantly compared with those in Group A (P<0.05). At the same time, the expression of CD18/CD11b and the main lung injury indexes in Group C decreased dramatically, compared those in Group B (P<0.05).

CONCLUSIONSThe infusion of albumin during resuscitation period can protect lungs from injury and decrease the expression of CD18/CD11b in T/HS rats.

Albumins ; therapeutic use ; Animals ; CD11b Antigen ; metabolism ; CD18 Antigens ; metabolism ; Disease Models, Animal ; Neutrophils ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Respiratory Distress Syndrome, Adult ; drug therapy ; etiology ; metabolism ; Shock, Hemorrhagic ; complications ; metabolism ; Treatment Outcome ; Wounds and Injuries ; complications ; metabolism