Normal Rat Liver Research Articles

DJ-1 deficiency alleviates steatosis in cultured hepatocytes

Imbalance in lipid metabolism within hepatocytes can lead to hepatosteatosis, which is a cause of numerous hepatic dysfunctions. Previous studies have demonstrated the roles of DJ-1 in Parkinson’s disease, diet-induced oxidative stress, obesity, and diabetes. Although recent studies have shown that DJ-1 is involved in metabolic complications, the roles of DJ-1 in steatosis are largely unknown. Therefore, the aim of the current study was to elucidate the potential roles of DJ-1 in hepatosteatosis in vitro. Normal rat liver cells Clone 9 (C9) were treated with 1 mM oleic acid (OA) for 24 h for establishment of a steatosis model, after which various biochemical parameters, including triglyceride, total cholesterol, and free fatty acid contents, were determined after knockdown with Dj1- specific siRNA. Silencing of Dj1 prevented hepatic steatosis by suppressing expression of hepatic lipogenic markers, which was confirmed by immunoblotting and real-time PCR analysis. Up-regulation of mitochondrial and β- oxidation-associated proteins showed potential to reduce fat accumulation in the liver. Silencing of Dj1 resulted in alleviation of steatosis by reducing lipogenesis and improving mitochondrial biogenesis. Further in vivo studies will be required to understand the molecular mechanism behind the role of DJ-1 in steatosis.

Nitrate/L-arginine Therapy and Nitric Oxide Levels in the Stomach and Liver of Rats

Background: The L-arginine/nitric oxide (NO) pathway is a major defensive system in gastric mucosa. Nitrate can restore NO homeostasis when enzymatic NO production becomes dysfunctional. Objectives: The aim of this study was to investigate the effects of nitrate/L-arginine administration on NO levels in the stomach and liver of rats. Materials and Methods: In this interventional study, adult male Wistar rats were divided into 3 groups of control, nitrate and L-arginine (n = 8). Rats in the nitrate and L-arginine groups were administered sodium nitrate (500 mg/L) or L-arginine (2%) for one week in drinking water while those in control group consumed tap water. At the end, serum, stomach and liver NO metabolite (NO x ) concentrations were measured by the Griess method. Results: Median (interquartile range) serum NO x concentrations in the control group [28.2 (19.6 - 37.8) μmol/L] were significantly (P < 0.05) different to those of the nitrate [152.4 (111.4 - 180.2) μmol/L] and L-arginine [14.5 (11.2 - 21.5) μmol/L] groups. Nitrate administration increased and L-arginine administration decreased stomach and liver NOx levels respectively. A positive correlation was observed between serum concentrations and stomach (r = 0.847, P < 0.001) and liver (r = 0.650, P = 0.006) NO x levels. Conclusions: Nitrate and L-arginine administration had opposite effects on NO x levels in stomach and liver of normal rats. Increase in stomach NO x following nitrate administration may be due to gastric nitrate absorption, while the decrease in tissue NO x following L-arginine administration may be due to increase in arginase activity. These findings may be important considering current data on the protective roles of dietary nitrate/nitrite.

Broccoli sprout extract induces detoxification-related gene expression and attenuates acute liver injury.

To investigate the effects of broccoli sprout extract (BSEx) on liver gene expression and acute liver injury in the rat. First, the effects of BSEx on liver gene expression were examined. Male rats were divided into two groups. The Control group was fed the AIN-76 diet, and the BSEx group was fed the AIN-76 diet containing BSEx. After a 10-d feeding period, rats were sacrificed and their livers were used for DNA microarray and real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses. Next, the effects of BSEx on acute liver injury were examined. In experiments using acute liver injury models, 1000 mg/kg acetaminophen (APAP) or 350 mg/kg D-galactosamine (D-GalN) was used to induce injury. These male rats were divided into four groups: Control, BSEx, Inducer (APAP or D-GalN), and Inducer+BSEx. The feeding regimens were identical for the two analyses. Twenty-four hours following APAP administration via p.o. or D-GalN administration via i.p., rats were sacrificed to determine serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, hepatic glutathione (GSH) and thiobarbituric acid-reactive substances accumulation and glutathione-S-transferase (GST) activity. Microarray and real-time RT-PCR analyses revealed that BSEx upregulated the expression of genes related to detoxification and glutathione synthesis in normal rat liver. The levels of AST (70.91 ± 15.74 IU/mL vs 5614.41 ± 1997.83 IU/mL, P < 0.05) and ALT (11.78 ± 2.08 IU/mL vs 1297.71 ± 447.33 IU/mL, P < 0.05) were significantly suppressed in the APAP + BSEx group compared with the APAP group. The level of GSH (2.61 ± 0.75 nmol/g tissue vs 1.66 ± 0.59 nmol/g tissue, P < 0.05) and liver GST activity (93.19 ± 16.55 U/g tissue vs 51.90 ± 16.85 U/g tissue, P < 0.05) were significantly increased in the APAP + BSEx group compared with the APAP group. AST (4820.05 ± 3094.93 IU/mL vs 12465.63 ± 3223.97 IU/mL, P < 0.05) and ALT (1808.95 ± 1014.04 IU/mL vs 3936.46 ± 777.52 IU/mL, P < 0.05) levels were significantly suppressed in the D-GalN + BSEx group compared with the D-GalN group, but the levels of AST and ALT in the D-GalN + BSEx group were higher than those in the APAP + BSEx group. The level of GST activity was significantly increased in the D-GalN + BSEx group compared with the D-GalN group (98.04 ± 15.75 U/g tissue vs 53.15 ± 8.14 U/g tissue, P < 0.05). We demonstrated that BSEx protected the liver from various types of xenobiotic substances through induction of detoxification enzymes and glutathione synthesis.

Effects of alfalfa saponin extract on mRNA expression of Ldlr, LXRα, and FXR in BRL cells.

We studied the effects of alfalfa saponin extract (ASE) on low density lipoprotein receptor (Ldlr), liver X receptor α (LXRα), and farnesoid X receptor (FXR) in normal and hyperlipidemic Buffalo rat liver (BRL) cells. Normal and hyperlipidemic BRL cells were divided into eight groups: normal, or normal cells treated with 50, 100, and 150 mg/L ASE, hyperlipidemic, or hyperlipidemic cells treated with 50, 100, and 150 mg/L ASE. After treatment for 24 h, Ldlr, LXRα, and FXR mRNA expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Data showed that mRNA expression of Ldlr in normal BRL cells was significantly up-regulated by ASE treatment and mRNA expressions of LXRα and FXR were significantly down-regulated both in normal and hyperlipidemic BRL cells after ASE treatment. Thus, ASE might ameliorate hepatic steatosis by regulating genes involved in cholesterol metabolism, including up-regulation of Ldlr as well as down-regulation of LXRα and FXR.

Dynamics of proglycogen and macroglycogen in hepatocytes of normal and cirrhotic rat liver at various stages of glycogenesis

The content and structure of glycogen in hepatocytes of normal and cirrhotic rat liver were examined at different time intervals after glucose administration to starving animals. We used an original cytofluorimetric method for detection and quantification of proglycogen (PG) and macroglycogen (MG) of isolated hepatocytes. The method is based on the use of reagents of the Schiff type with different spectral characteristics. The content of MG in hepatocytes of control rats was increased by 52% (p < 0.01) as early as after 10 min. The MG content in the cirrhotic liver cells was increased by 43% (p < 0.05) only 20 min after glucose administration to the starving animals. The correlation coefficient between MG content and the total glycogen content at various stages of glycogenesis in rats of both groups was from 0.90 to 0.99 (p < 0.001). Increase in the PG content in hepatocytes of control rats was observed in intervals of 10–30 and 45–75 min. The PG content in cirrhosis was increased only in 60 min after the beginning of glycogenesis, but in 120 min it was 1.5 times higher than the control values (p < 0.001). The correlation coefficients between PG and the total glycogen content in the cells were on average 0.86 (p < 0.001) and 0.77 (p < 0.001) in the control and experimental groups, respectively. Thus, the change in the total glycogen content in hepatocytes of normal and cirrhotic liver are associated mainly with changes in the MG level. The contribution of PG was most significant in normal liver at the beginning of glycogenesis (10–30 min); in cirrhotic liver, at later stages (75–120 min).

Synthesis and biological evaluation of geldanamycin analogs against human cancer cells.

To find novel potential and less toxic benquinone anamycin heat shock protein 90 (Hsp90) inhibitors as anticancer agents, a limited series of 17-substituted or 17,19-disubstituted 17-demethoxygeldanamycin analogs were synthesized and tested for anti-proliferation activity against human cancer cells. Liver toxicity was also tested in vivo. Five 17-alkylamino-17-demethoxygeldanamycins and two 17-alkylamino-19-methylthio-17-demethoxygeldanamycins were synthesized from geldanamycin (GA) and 19-methylthiogeldanamycin (19-S(methyl)-GA), respectively. Anti-proliferation activities of the GA analogs were determined in MCF7, HeLa, HCT116 and HepG2 cells using the MTT method. Western blot and cell cycle analyses were performed for mechanistic study. The growth inhibition effect of potential geldanamycins was also investigated in normal Buffalo rat liver (BRL) cells. In vivo liver toxicity was tested in Institute of Cancer Research (ICR) mice by tail vein injection of the tested compounds. Most of the 17-alkylaminogeldanamycins exhibited obvious growth inhibition effects on multiple human cancer cell lines. The anti-proliferation activity of 19-methylthio-substituted geldanamycins was significantly lower compared with no 19-substitution geldanamycins in all tested cancer cells. The compound 1b (17-[2-(piperidinyl-1'-yl)-ethylamino]-17-demethoxygeldanamycin) exhibited the highest anti-proliferation activity in MCF7, HeLa and HCT116 cells, which was much more effective than GA and the developing Hsp90 inhibitor 17-AAG (17-allylamino-17-demethoxygeldanamycin). Meanwhile, compound 1b exhibited weaker growth inhibition effect on BRL cell line than GA and 17-AAG. 1b induced cell cycle arrest at the G2/M phase in MCF7 cells. Cleavage of PARP associated with apoptosis and degradation of the Hsp90 client protein Akt and Her2 was also induced by treatment of 1b in HeLa and MCF7 cell lines. In spite of the relatively weaker activity of 1b compared with GA and 17-AAG against HepG2 cells, 1b was further identified with lower hepatotoxicity than GA in vivo. Compound 1b is regarded as a new potential Hsp90 inhibitor with low hepatotoxicity for further study.

Effect of Natural Products on Some Glycosidases and Their Expected Hypoglycemic Potential

Aims: It is to screen many natural product extracts for their in vitro and in vivo effects on the activities of hepatic α-amylase and α-glucosidase to validate their biological importance. Study Design: Different groups of non-diabetic and diabetic rats were treated by different plants for the in vivo study of glycosidases. In vitro effect of the plants on the tested enzymes was studied in presence and absence of their aqueous extract. Place and Duration of Study: Department of Biological & Environmental Sciences, Faculty of Science, Beirut Arab University, Beirut, Lebanon, between March 2013 and February 2014. Methodology: Enzymes were extracted from the livers of normal rats, also the natural products extracts were prepared for the in vitro studies. α-Amylase and α-glucosidase assays were done in the presence and absence of each plant extract. For the in vivo studies, normal non-diabetic rats were divided into groups, whereas the first group is a control that includes rats fed on normal food diet. The other groups include rats fed on normal food diet mixed with the tested plant leaves (20 Original Research Article Balbaa et al.; IJBCRR, 5(2): 95-106, 2015; Article no.IJBCRR.2015.012 96 mg/g body weight/day) Diabetes was induced in diabetic rats by single intraperitonial injection of streptozotocin. Diabetic rats were divided into groups and treated like the non-diabetic rats. Results: Only Thymus vulgaris and Origanum vulgare extracts showed a significant in vitro dosedependent inhibition on α-amylase with IC50 values of 0.2±0.01 and 0.37±0.03mg/ml, respectively. However, the in vivo effect was not detected for four weeks treatment for the two enzymes. The in vitro treatment of α-amylase by Thymus vulgaris and Origanum vulgare extracts exhibited a mixedtype inhibition. Moreover, the in vivo inhibition of both extracts on the tested hepatic enzymes was not detected in streptozotocin-induced diabetic rats fed on Thymus vulgaris and Origanum vulgare for four weeks. Blood sugar level was non-significantly decreased with respect to that of nontreated rats. Conclusion: some non anti-diabetic plant extracts possess an in vitro inhibition of glycosidases.

Synthesis and evaluation of fatty acid amides on the N-oleoylethanolamide-like activation of peroxisome proliferator activated receptor α.

A series of fatty acid amides were synthesized and their peroxisome proliferator-activated receptor α (PPAR-α) agonistic activities were evaluated in a normal rat liver cell line, clone 9. The mRNAs of the PPAR-α downstream genes, carnitine-palmitoyltransferase-1 and mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase, were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) as PPAR-α agonistic activities. We prepared nine oleic acid amides. Their PPAR-α agonistic activities were, in decreasing order, N-oleoylhistamine (OLHA), N-oleoylglycine, Oleamide, N-oleoyltyramine, N-oleoylsertonin, and Olvanil. The highest activity was found with OLHA. We prepared and evaluated nine N-acylhistamines (N-acyl-HAs). Of these, OLHA, C16:0-HA, and C18:1Δ(9)-trans-HA showed similar activity. Activity due to the different chain length of the saturated fatty acid peaked at C16:0-HA. The PPAR-α antagonist, GW6471, inhibited the induction of the PPAR-α downstream genes by OLHA and N-oleoylethanolamide (OEA). These data suggest that N-acyl-HAs could be considered new PPAR-α agonists.

Collagen arrangement in space of Disse correlates with fluid flow in normal and cirrhotic rat livers.

Little is known about collagen arrangement in the space of Disse was related to the fluid flow both in normal and cirrhotic liver. We examined the changes in the arrangement of type-I collagen in thioacetamide-induced cirrhotic rat livers with immunohistochemistry and SEM after maceration of the noncollagenous tissues with NaOH. The sparse bundles of collagen fibers in the spaces of Disse were mostly elongated fibers with a disorganized arrangement in each nodule. They connected with the broad fibrous septa. Based on a comparison of the architecture of the collagen fibers and the established flow of fluid in the space of Disse, we hypothesize that the fluid in the space of Disse streams along collagen fibers in all directions to broad fibrous septa. The appearance of perinodular plexus in cirrhotic rat livers probably helps to reduce portal hypertension.

Biological Effect of Glycosyl-Oxadiazolinethione and Glycosyl-sulfanyloxadiazole Derivatives through their in vitro Inhibition of Glycosidases from Bacteria and Normal or Diabetic Rats

The inhibition of glycosidases from bacteria and the liver of normal and diabetic rats by 2-(tetra-O-acetyl-β-Dglucopyranosylsulfanyl)- 5-(1-benzyl-1H-indol-2-yl)-1,3,4-oxadiazole BnM-3B; 3-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)- 5-(1H-indol-2-yl)-1,3,4-oxadiazole- 2(3H)-thione MTB-4A; 3-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-Dglucopyranosyl)- 5-(1-benzyl-1H-indol-2-yl)-1,3,4-oxadiazole-2(3H)-thione BnN-5A has been investigated. In vitro treatment of hepatic α-amylase and β-glucuronidase from control and streptozotocin-induced diabetic rats by S- and Nglycosyl analogues from oxadiazolinethione derivatives exhibited a significant dose-dependent decrease on the specific activity of both α-amylase and β-glucuronidase. Moreover, these compounds also exhibited a significant decrease on the specific activity of α-amylase and α-glucosidase produced by Bacillus subtilis AH. The observed IC50 values of these compounds are much lower than that of ethanolamines, higher for α-glucosidase than α-amylase from bacteria and significantly lower for hepatic α-amylase and β-glucuronidase from diabetic rats. The obtained results suggest that these compounds are good inhibitors that act on glycosidases from bacteria and normal / diabetic rats in different mechanisms. Keywords: Enzyme inhibitors, ethanolamines, glycosidases, glycosyl-sulfanyl-oxadiazole, oxadiazolinethione.

Astragalus and Paeoniae Radix Rubra extract (APE) inhibits hepatic stellate cell activation by modulating transforming growth factor-β/Smad pathway.

Previous studies have shown that Astragalus and Paeoniae Radix Rubra extract (APE) is capable of protecting against liver fibrosis in rats. The hypothesis of the present study was that APE exerts its anti-fibrotic effect by mediating the transforming growth factor β (TGF-β)/Smad signaling pathway. In order to investigate this hypothesis, a series of assays were designed to detect the effects of APE on cell proliferation, cell invasion and the activation of hepatic stellate cells (HSCs). In addition, the effects of APE on the TGF-β/Smad signaling pathway were explored, with the aim of elucidating the underlying mechanisms. HSCs were initially isolated from normal rat liver. A number of assays were then employed in order to evaluate the effects of APE on the function of these cells. Cell proliferation was investigated using an MTT assay and cell invasion was observed with the use of transwell invasion chambers. Collagen synthesis was measured with a 3H-proline incorporation assay and expression of α-smooth muscle actin was used to determine the extent of HSC activation. Protein expression induced by TGF-β1 in HSCs was investigated by western blot and immunofluorescence analyses. Plasminogen activator inhibitor type1 (PAI-1) and urokinase-type plasminogen activator (uPA) transcriptional activity was measured using reverse transcription polymerase chain reaction. The results demonstrated that APE (5–80 μg/ml) significantly inhibited fetal bovine serum-induced cell proliferation in a dose-dependent manner. Cell invasion and activation of HSCs induced by TGF-β1 were disrupted by treatment with APE in a dose-dependent manner. TGF-β1 was observed to increase the phosphorylation of Smad2/3, while APE administered at higher doses produced inhibitory effects on Smad2/3 phosphorylation. In addition, administration of APE abrogated the TGF-β1-induced reduction in Smad-7 expression in a dose-dependent manner. The results further indicated that APE treatment not only reduced PAI-1 expression, but also increased uPA expression in a dose-dependent manner. In conclusion, APE exerted inhibitory effects on cell proliferation, invasion and activation of HSCs, and the mechanisms underlying these effects may involve the TGF-β1/Smad pathway.

Identification and Characterization of Mesenchymal-Epithelial Progenitor-Like Cells in Normal and Injured Rat Liver

In normal rat liver, thymocyte antigen 1 (Thy1) is expressed in fibroblasts/myofibroblasts and in some blood progenitor cells. Thy1-expressing cells also accumulate in the liver during impaired liver regeneration. The origin and nature of these cells are not well understood. By using RT-PCR analysis and immunofluorescence microscopy, we describe the presence of rare Thy1(+) cells in the liver lobule of normal animals, occasionally forming small collections of up to 20 cells. These cells constitute a small portion (1.7% to 1.8%) of nonparenchymal cells and reveal a mixed mesenchymal-epithelial phenotype, expressing E-cadherin, cytokeratin 18, and desmin. The most potent mitogens for mesenchymal-epithelial Thy1(+) cells invitro are the inflammatory cytokines interferon γ, IL-1, and platelet-derived growth factor-BB, which are not produced by Thy1(+) cells. Thy1(+) cells express all typical mesenchymal stem cell and hepatic progenitor cell markers and produce growth factor and cytokine mRNA (Hgf, Il6, Tgfa, and Tweak) for proteins that maintain oval cell growth and differentiation. Under appropriate conditions, mesenchymal-epithelial cells differentiate invitro into hepatocyte-like cells. In this study, we show that the adult rat liver harbors a small pool of endogenous mesenchymal-epithelial cells not recognized previously. In the quiescent state, these cells express both mesenchymal and epithelial cell markers. They behave like hepatic stem cells/progenitors with dual phenotype, exhibiting high plasticity and long-lasting proliferative activity.

Expression and distribution of immunoglobulin G in the normal liver, hepatocarcinoma and postpartial hepatectomy liver

The liver has the extraordinary properties of regeneration and immune tolerance; however, the mechanisms governing these abilities are poorly understood. To address these questions, we examined the possible expression of immunoglobulins in the human and rat liver and the relationship of IgG expression to hepatocyte proliferation, metastasis, apoptosis and immune tolerance. Immunohistochemistry, in situ hybridization, laser-guided microdissection and reverse transcription-PCR were performed to examine the expression of IgG in normal human and rat liver, severe combined immunodeficient mouse (SCID) liver and human liver cancers and corresponding cell lines. Small interfering RNA (siRNA) was transfected into cultured hepatocarcinoma cells to downregulate the expression of IgG heavy chain genes. Cell proliferation and apoptosis were assayed with flow cytometry. Cell metastasis was assayed with a Transwell cell assay. Partial hepatectomy (70%) was performed in rats to examine the relationship between hepatocyte IgG and hepatocyte proliferation. IgG, together with essential enzymes for its synthesis, were expressed in the cytoplasm of hepatocytes of normal adult human and hepatoma patients and rat livers, SCID mouse liver and BRL-3A, L-02 and HepG-2 cell lines. Downregulation of IgG inhibited cell proliferation and metastasis and promoted apoptosis. Postsurgery livers expressed significantly more IgG than the livers before surgery and decreased to the original levels when hepatocytes stopped regeneration. IgA and IgM but not IgD and IgE were also positive in hepatocytes. Our findings demonstrate that normal and malignant hepatocytes are capable of synthesizing immunoglobulin, which has important roles in hepatocyte proliferation, apoptosis and cancer growth with profound clinical implications.

Hepatotoxicity and liver injury induced by hydroxyapatite nanoparticles.

As hydroxyapatite nanoparticles (HA NPs) are increasingly used in biomedical and biotechnological fields, risk assessment of HA NPs has attracted extensive attention. Nevertheless, little is known about the potential adverse effects of HA NPs on normal hepatocytes and the liver. In the present study, we conducted an in vitro study in which 80-nm HA NPs were incubated with normal Buffalo rat liver (BRL) cells. By analyzing the changes in cell viability, apoptosis/necrosis and the mitogen-activated protein kinase (MAPK) signaling pathway, we investigated the cytotoxicity and potential mechanism of HA NPs in hepatocytes. Furthermore, we used the serum hematology and histopathology examinations to explore the in vivo effects of HA NPs on the structure and function of the liver. Our results showed that exposure to HA NPs at a concentration above 200 µg ml(-1) decreased cell viability, increased levels of lactate dehydrogenase (LDH) leakage, induced apoptosis and necrosis, and triggered the MAPK signaling pathway in BRL cells in a dose-dependent manner. Moreover, our in vivo study indicated that HA NPs increased the white blood cell count (WBC) and the levels of tumor necrosis factor-α (TNF-α), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum, caused inflammatory cell infiltration at the portal area in the liver, and induced hepatic oxidative stress with elevated levels of hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA). These data demonstrate that at certain concentrations, 80-nm HA NPs cause hepatotoxicity and liver injury.

Whole-organ tissue engineering: decellularization and recellularization of three-dimensional matrix liver scaffolds.

To report the results of whole liver decellularization by two different methods. To present the results of grafting rat and sheep decellularized liver matrix (DLM) into the normal rat liver and compare natural cell seeding process in homo/xenograft of DLM. To compare the results of in vitro whole liver recellularization with rats' neonatal green fluorescent protein (GFP)-positive hepatic cells with outcomes of in vivo recellularization process. Whole liver of 8 rats and 4 sheep were resected and cannulated via the hepatic vein and perfused with sodium dodecyl sulfate (SDS) or Triton + SDS. Several examinations were performed to compare the efficacy of these two decellularization procedures. In vivo recellularization of sheep and rat DLMs was performed following transplantation of multiple pieces of both scaffolds in the subhepatic area of four rats. To compare the efficacy of different scaffolds in autologous cell seeding, biopsies of homograft and xenograft were assessed 8 weeks postoperatively. Whole DLMs of 4 rats were also recellularized in vitro by perfusion of rat's fetal GFP-positive hepatic cells with pulsatile bioreactor. Histological evaluation and enzymatic assay were performed for both in vivo and in vitro recellularized samples. The results of this study demonstrated that the triton method was a promising decellularization approach for preserving the three-dimensional structure of liver. In vitro recellularized DLMs were more similar to natural ones compared with in vivo recellularized livers. However, homografts showed better characteristics with more organized structure compared with xenografts. In vitro recellularization of liver scaffolds with autologous cells represents an attractive prospective for regeneration of liver as one of the most compound organs. In vivo cell seeding on the scaffold of the same species may have more satisfactory outcomes when compared with the results of xenotransplantation. This study theoretically may pave the road for in situ liver regeneration probably by implantation of homologous DLM or in vitro recellularized scaffolds into the diseased host liver.

A GAPDH-Mediated Trans-Nitrosylation Pathway Is Required for Feedback Inhibition of Bile Salt Synthesis in Rat Liver

Bile salts inhibit their own production by inducing the nuclear receptor small heterodimer partner (SHP) (encoded by NR0B2), which contributes to repression of the gene encoding cholesterol 7α-hydroxylase (CYP7A1), a key enzyme for the control of bile salt synthesis. On the other hand, bile salts stimulate hepatic synthesis of nitric oxide. We investigated the role of nitric oxide signaling in thecontrol of CYP7A1 expression and the involvement in thisprocess of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which participates in intracellular propagation of nitric oxide signals. We studied the effects of inhibitors of nitric oxide synthesis (L-NG-nitroarginine methyl ester [L-NAME]) or protein nitrosylation (via dithiothreitol) on bile salt homeostasis in male Wistar rats placed on a cholate-rich diet for 5 days and in cultured primary hepatocytes. S-nitrosylation of GAPDH was assessed using a biotin-switch assay. Interacions of SHP with other proteins and with the Cyp7a1 promoter sequence were studied using immunoprecipitation and chromatin immunoprecipitation (ChIP) assays. We reduced the GAPDH levels in H35 cells with small interfering RNAs. GAPDH nitrosylation was assessed in normal and cholestatic rat and human livers. Rats placed on cholate-rich diets and given L-NAME had increased intrahepatic and biliary levels of bile salts, and deficiency in repression of CYP7A1 (at the messenger RNA and protein levels) in liver tissue, despite preserved induction of SHP. In cultured hepatocytes, L-NAME or dithiothreitol blocked cholate-induced down-regulation of CYP7A1 without impairing SHPup-regulation. In hepatocytes, cholate promoted S-nitrosylation of GAPDH and its translocation to the nucleus, accompanied by S-nitrosylation of histone deacetylase 2(HDAC2) and Sirtuin 1 (SIRT1), deacetylases that participate, respectively, in the formation of Cyp7a1 and Shp repressor complexes. Knockdown of GAPDH prevented repression of CYP7A1 by cholate, and blocking nuclear transport of nitrosylated GAPDH reduced cholate-induced nitrosylation of HDAC2 and SIRT1; this effect was accompanied by abrogation of Cyp7a1 repression. Cholate induced binding of SHP to HDAC2 and its recruitment to the Cyp7a1 promoter; these processes were inhibited by blocking nitric oxide synthesis. Levels of nitrosylated GAPDH and nitrosylated HDAC2 were increased in cholestatic human and rat livers reflecting increased concentrations of bile salts in these conditions. In rat liver, excess levels of bile salts activate a GAPDH-mediated transnitrosylation cascade that provides feedback inhibition of bile salt synthesis.

Pattern of microRNA expression associated with different stages of alcoholic liver disease in rat models.

Emerging evidence has suggested that aberrant expression of micro (mi)RNAs contributes to the development of alcoholic liver injury (ALD). However, miRNA profiles distinguishing different stages of ALD have not yet been reported. The present study was designed to investigate the unique miRNA expression patterns at different stages of ALD in a rat model and analyze the gene functions and pathways of dysregulated miRNA-targeted genes. Using microarray and stem-loop quantitative polymerase chain reaction analyses, 16 miRNAs were identified as upregulated and 13 were identified as downregulated in an alcoholic steatohepatitis (ASH) group compared with the control group, while five miRNAs were identified to be upregulated and eight were identified to be downregulated in the alcoholic fatty liver (AFL) group as compared with the control group. Following further confirmation by Significance Analysis of Microarray and prediction by Prediction Analysis of Microarray, 8 and 12 types of miRNA were screened as molecular signatures in distinguishing AFL and ASH, respectively, from normal rat liver. In addition, several miRNA-target pairs were predicted by computer-aided algorithms (Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses using the Database for Annotation, Visualization and Integrated Discovery platform) and these genes may be involved in cancer signaling pathways, the Wnt signaling pathway and other signaling pathways. These results may provide novel miRNA targets for diagnosis and therapeutic intervention at different stages of ALD.

Window-modulated compounding Nakagami imaging for ultrasound tissue characterization

Ultrasound Nakagami parametric imaging is a useful tool for tissue characterization. Previous literature has suggested using a square with side lengths corresponding to 3 times the transducer pulse length as the minimum window for constructing the Nakagami image. This criterion does not produce sufficiently smooth images for the Nakagami image to characterize homogeneous tissues. To improve image smoothness, we proposed window-modulated compounding (WMC) Nakagami imaging based on summing and averaging the Nakagami images formed using sliding windows with varying window side lengths from 1 to N times the transducer pulse length in 1 pulse length step. Simulations (the number densities of scatterers: 2–16 scatterers/mm2) and experiments on fully developed speckle phantoms (the scatterer diameters: 20–106μm) were conducted to suggest an appropriate number of frames N and to evaluate the image smoothness and resolution by analyzing the full width at half maximum (FWHM) of the parameter distribution and the widths of the image autocorrelation function (ACF), respectively. In vivo ultrasound measurements on rat livers without and with cirrhosis were performed to validate the practical performance of the WMC Nakagami image in tissue characterization. The simulation results showed that using a range of N from 7 to 10 as the number of frames for image compounding reduces the estimation error to less than 5%. Based on this criterion, the Nakagami parameter obtained from the WMC Nakagami image increased from 0.45 to 0.95 after increasing the number densities of scatterers from 2 to 16 scatterers/mm2. The FWHM of the parameter distribution (bins=40) was 13.5±1.4 for the Nakagami image and 9.1±1.43 for the WMC Nakagami image, respectively (p-value<.05). The widths of the ACF for the Nakagami and WMC Nakagami images were 454±5.36 and 458±4.33, respectively (p-value>.05). In the phantom experiments, we also found that the FWHM of the parameter distribution for the WMC Nakagami image was smaller than that of the conventional Nakagami image (p-value<.05), and there was no significant difference of the ACF width between the Nakagami and WMC Nakagami images (p-value>.05). In the animal experiments, the Nakagami parameters obtained from the WMC Nakagami image for normal and cirrhotic rat livers were 0.62±0.08 and 0.92±0.07, respectively (p-value<.05). The results demonstrated that the WMC technique significantly improved the image smoothness of Nakagami imaging without resolution degradation, giving Nakagami model-based imaging the ability to visualize scatterer properties with enhanced image quality.

Experimental Study &lt;i&gt;Oviductus ranae&lt;/i&gt; for the Change of α-SMA and TGF-β in Hepatic Fibrosis Rat Liver

To evaluate the control effect of Oviductus ranae on liver fibrosis in rats, and the change of TGF-β and α-SMA in liver of. To explore the mechanism of Oviductus ranae decoction on liver fibrosis. Methods Wistar female rats were randomly divided into a blank control group, model control group, colchicines group, Oviductus ranae group. Using the CCl4composite approach to make the rat modle. The course of treat-mart was 12 weeks.After treatment,All the rats was killed,and the materials and blood was taken,and to detect biochemical test of liver function after eight weeks. Investigating the variation of liver histology. Meanwhile detecting protein expression of TGF-β and α-SMA and by immunehistochemical method.Result The general condition of rats in all treatment groups are worse than the blank group,but better than the model group. And the rats in the model group were all occurred in liver fibrosis,and liver fibrosis is the most serious.In a normal rat liver tissue of TGF-β and α-SMA were significantly lower in model group and each treatment group, and there were significant differences, and the TGF-β and α-SMA in expression of liver tissue in model rats of TGF-β and α-SMA the highest. Conclusion: Oviductus ranae can effectively improve liver fibrosis rats induced by CC14liver function.Oviductus ranae can reduce the expression of TGF-β1in liver tissue of hepatic fibrosis rats induced by CCl4in. This may be one of the mechanisms of Oviductus ranae in prevention and treatment of liver fibrosis. Even though both increased expression of TGF-β and α-SMA expression, is able to determine TGF-β and α-SMA for the intervention of liver TGF-β signal transduction pathway in liver fibrosis.

Pharmacological study on free anthraquinones compounds in rhubarb in rats with experimental acute pancreatitis

To verify the pharmacological hypothesis of prescriptions by studying the targeted distribution of major components in stewed rhubarb in the rat model with acute pancreatitis (AP). Normal SD rats (control group, n = 5) and the AP model induced with intraperitoneal cerulein (model group, n = 5) were taken as the experimental objects. Rats of the two groups were orally administered with stewed rhubarb granules (20 g x kg(-1)). Their heart, liver, spleen, lung, kidney and pancreas were collected two hours after the administration. Such constituents as emodin, chrysophanol, physcion, rhein and aloe-emodin and their concentrations in each tissue homogenate were detected by high performance liquid chromatography-mass-mass. Aloe-emodin and physcion in stewed rhubarb whose concentrations in liver and kidney of normal rats were higher than that in pancreatic tissues, while the distribution spectrums and concentrations of the remaining components in pancreatic tissues had no significant difference with that of other organs. The concentrations of emodin, aloe-emodin, rhein and chrysophanol in stewed rhubarb in pancreatic tissues of the AP model group were higher than that in other tissues and organs, while their concentrations in pancreatic, renal and splenic tissues were notably higher than that in the normal group. In the conditions of AP, effective components in stewed rhubarb show a targeted distribution feature in pancreas, which provides experimental basis for the pharmacological hypothesis of prescriptions.