S1591 Use of Precision-Cut Liver Slices from Asialoglycoprotein Receptor-Deficient and Wild-Type Mice to Examine a Role for This Receptor During Toxin-Induced Liver Injury

Background: Work from our laboratory has shown that the ethanol-induced increase in apoptotic hepatocellular death is closely related to the impairment in the ability of the asialoglycoprotein receptor (ASGP-R) to remove neighboring apoptotic cells. In this study, we assessed the role of ASGP-R in fulminant liver failure and investigated whether prior treatment with betaine (a naturally occurring tertiary amine) is protective. Methods: Lipopolysaccharide (LPS; 50 μg/kg BW) and galactosamine (GalN; 350 mg/kg BW) were injected together to wild-type and ASGP-R-deficient mice that were treated for two weeks prior with or without 2% betaine in drinking water. The mice were sacrificed 1.5, 3, or 4.5 h post-injection, and tissue samples were collected. Results: LPS/GalN injection generate distinct molecular processes, which includes increased production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), thus causing apoptosis as evident by increased caspase-3 activity. ASGP-R deficient animals showed increased liver caspase activities, serum TNF-α and IL-6 levels, as well as more pronounced liver damage compared with the wild-type control animals after intraperitoneal injection of LPS/GalN. In addition, prior administration of betaine was found to significantly attenuate the LPS/GalN-induced increases in liver injury parameters. Conclusion: Our work underscores the importance of normal functioning of ASGP-R in preventing severe liver damage and signifies a therapeutic role of betaine in prevention of liver injuries from toxin-induced fulminant liver failure.

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Stem cell factor and c-kit are involved in hepatic recovery after acetaminophen-induced liver injury in mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00024.2008 ◽

2008 ◽

Vol 295 (1) ◽

pp. G45-G53 ◽

Cited By ~ 35

Author(s):

Bin Hu ◽

Lisa M. Colletti

Keyword(s):

Stem Cell ◽

Liver Injury ◽

Stem Cell Factor ◽

Cellular Proliferation ◽

Hepatocyte Proliferation ◽

Mrna Levels ◽

Wild Type ◽

Hepatocyte Apoptosis ◽

Large Reservoir ◽

A Cell

Stem cell factor (SCF) and its receptor c-kit are important in hematopoiesis and cellular proliferation. c-kit has also been identified as a cell surface marker for progenitor cells. We have previously shown that there is a large reservoir of hepatic SCF, and this molecule plays a significant role in liver regeneration after 70% hepatectomy. In the current study, we further examined the expression of SCF and c-kit in acetaminophen (APAP)-induced liver injury in C57BL/6J mice or SCF-deficient sl-sld mice and their appropriate wild-type controls. Following APAP-induced liver injury, c-kit mRNA expression increased, with peak levels detected 48 h postinjury. Hepatic SCF mRNA levels after APAP injury were also increased, with peak levels seen 16 h post-APAP. The mortality rate in SCF-deficient mice treated with APAP was significantly higher than that of wild-type mice; furthermore, administration of exogenous SCF significantly reduced the mortality of APAP-treated wild-type mice. Bromodeoxyuridine incorporation experiments showed that SCF significantly increased hepatocyte proliferation at 48 and 72 h in APAP-treated mice. SCF inhibited APAP-induced hepatocyte apoptosis and increased Bcl-2 and Bcl-xL expression, suggesting that this decrease in hepatocyte apoptosis is mediated through Bcl-2 and Bcl-xL. In summary, SCF and c-kit expression was increased after APAP-induced liver injury. Administration of exogenous SCF reduces mortality in APAP-treated mice, increases hepatocyte proliferation, and prevents hepatocyte apoptosis induced by APAP, suggesting that these molecules are important in the liver's recovery from these injuries.

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Phosphatidylcholine transfer protein/StarD2 promotes microvesicular steatosis and liver injury in murine experimental steatohepatitis

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00379.2016 ◽

2017 ◽

Vol 313 (1) ◽

pp. G50-G61 ◽

Cited By ~ 6

Author(s):

Hayley T. Nicholls ◽

Jason L. Hornick ◽

David E. Cohen

Keyword(s):

Liver Injury ◽

Lipid Droplets ◽

Plasma Concentrations ◽

Fibroblast Growth Factor 21 ◽

Wild Type ◽

Hepatocellular Injury ◽

Pathogenic Role ◽

Deficient Diet ◽

Transfer Protein ◽

Phosphatidylcholine Transfer Protein

Mice fed a methionine- and choline-deficient (MCD) diet develop steatohepatitis that recapitulates key features of nonalcoholic steatohepatitis (NASH) in humans. Phosphatidylcholine is the most abundant phospholipid in the surfactant monolayer that coats and stabilizes lipid droplets within cells, and choline is required for its major biosynthetic pathway. Phosphatidylcholine-transfer protein (PC-TP), which exchanges phosphatidylcholines among membranes, is enriched in hepatocytes. PC-TP also regulates fatty acid metabolism through interactions with thioesterase superfamily member 2. We investigated the contribution of PC-TP to steatohepatitis induced by the MCD diet. Pctp−/− and wild-type control mice were fed the MCD diet for 5 wk and were then euthanized for histopathologic and biochemical analyses, as well as determinations of mRNA and protein expression. Whereas all mice developed steatohepatitis, plasma alanine aminotransferase and aspartate aminotransferase activities were only elevated in wild-type mice, indicating that Pctp−/− mice were protected from MCD diet-induced hepatocellular injury. Reduced hepatotoxicity due to the MCD diet in the absence of PC-TP expression was further evidenced by decreased activation of c-Jun and reduced plasma concentrations of fibroblast growth factor 21. Despite similar total hepatic concentrations of phosphatidylcholines and other lipids, the relative abundance of microvesicular lipid droplets within hepatocytes was reduced in Pctp−/− mice. Considering that the formation of larger lipid droplets may serve to protect against lipotoxicity in NASH, our findings suggest a pathogenic role for PC-TP that could be targeted in the management of this condition. NEW & NOTEWORTHY Phosphatidylcholine-transfer protein (PC-TP) is a highly specific phosphatidylcholine-binding protein that we previously showed to regulate hepatocellular nutrient metabolism through its interacting partner thioesterase superfamily member 2 (Them2). This study identifies a pathogenic role for PC-TP, independent of Them2, in the methionine- and choline-deficient diet model of experimental steatohepatitis. Our current observations suggest that PC-TP promotes liver injury by mediating the intermembrane transfer of phosphatidylcholines, thus stabilizing more pathogenic microvesicular lipid droplets.

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Cell-specific regulatory effects of CXCR2 on cholestatic liver injury

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00080.2019 ◽

2019 ◽

Vol 317 (6) ◽

pp. G773-G783 ◽

Cited By ~ 2

Author(s):

Takanori Konishi ◽

Rebecca M. Schuster ◽

Holly S. Goetzman ◽

Charles C. Caldwell ◽

Alex B. Lentsch

Keyword(s):

Bile Duct ◽

Liver Injury ◽

Liver Damage ◽

Chemokine Receptor ◽

Therapeutic Target ◽

Bile Duct Ligation ◽

Wild Type ◽

Neutrophil Accumulation ◽

Duct Ligation ◽

Cholestatic Liver Injury

The CXC chemokine receptor 2 (CXCR2) is critical for neutrophil recruitment and hepatocellular viability but has not been studied in the context of cholestatic liver injury following bile duct ligation (BDL). The present study sought to elucidate the cell-specific roles of CXCR2 on acute liver injury after BDL. Wild-type and CXCR2−/− mice were subjected BDL. CXCR2 chimeric mice were created to assess the cell-specific role of CXCR2 on liver injury after BDL. SB225002, a selective CXCR2 antagonist, was administrated intraperitoneally after BDL to investigate the potential of pharmacological inhibition. CXCR2−/− mice had significantly less liver injury than wild-type mice at 3 and 14 days after BDL. There was no difference in biliary fibrosis among groups. The chemokines CXCL1 and CXCL2 were induced around areas of necrosis and biliary structures, respectively, both areas where neutrophils accumulated after BDL. CXCR2−/− mice showed significantly less neutrophil accumulation in those injured areas. CXCR2Liver+/Myeloid+ and CXCR2Liver−/Myeloid− mice recapitulated the wild-type and CXCR2-knockout phenotypes, respectively. CXCR2Liver+/Myeloid+ mice suffered higher liver injury than CXCR2Liver+/Myeloid− and CXCR2Liver−/Myeloid+; however, only those chimeras with knockout of myeloid CXCR2 (CXCR2Liver+/Myeloid− and CXCR2Liver−/Myeloid−) showed reduction of neutrophil accumulation around areas of necrosis. Daily administration of SB225002 starting after 3 days of BDL reduced established liver injury at 6 days. In conclusion, neutrophil CXCR2 guides the cell to the site of injury, while CXCR2 on liver cells affects liver damage independent of neutrophil accumulation. CXCR2 appears to be a viable therapeutic target for cholestatic liver injury. NEW & NOTEWORTHY This study is the first to reveal cell-specific roles of the chemokine receptor CXCR2 in cholestatic liver injury caused by bile duct ligation. CXCR2 on neutrophils facilitates neutrophil recruitment to the liver, while CXCR2 on liver cells contributes to liver damage independent of neutrophils. CXCR2 may represent a viable therapeutic target for cholestatic liver injury.

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Toxic liver injury and carcinogenesis. Methylation of proteins of rat-liver slices by dimethylnitrosamine in vitro

Biochemical Journal ◽

10.1042/bj0830106 ◽

1962 ◽

Vol 83 (1) ◽

pp. 106-114 ◽

Cited By ~ 105

Author(s):

PN MAGEE ◽

T HULTIN

Keyword(s):

Liver Injury ◽

Rat Liver ◽

Liver Slices ◽

Toxic Liver Injury

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Galactose-specific asialoglycoprotein receptor is involved in lipoprotein (a) catabolism

Biochemical Journal ◽

10.1042/bj20030932 ◽

2003 ◽

Vol 376 (3) ◽

pp. 765-771 ◽

Cited By ~ 25

Author(s):

Andelko HRZENJAK ◽

Sasa FRANK ◽

Xingde WO ◽

Yonggang ZHOU ◽

Theo van BERKEL ◽

...

Keyword(s):

Physiological Function ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Asialoglycoprotein Receptor ◽

Fractional Catabolic Rate ◽

Wild Type ◽

Lipoprotein A ◽

Apolipoprotein A ◽

Catabolic Rate ◽

First Time

Lp(a) [lipoprotein (a)] is a highly atherogenic plasma lipoprotein assembled from low-density lipoprotein and the glycoprotein apolipoprotein (a). The rate of Lp(a) biosynthesis correlates significantly with plasma Lp(a) concentrations, whereas the fractional catabolic rate does not have much influence. So far, little is known about Lp(a) catabolism. To study the site and mode of Lp(a) catabolism, native or sialidase-treated Lp(a) was injected into hedgehogs or ASGPR (asialoglycoprotein receptor)-knockout (ASGPR−) mice or wild-type (ASGPR+) mice, and the decay of the plasma Lp(a) concentration was followed. COS-7 cells were transfected with high- (HL-1) and low-molecular-mass ASGPR subunits (HL-2), and binding and degradation of intact or desialylated Lp(a) were measured. In hedgehogs, one of the few species that synthesize Lp(a), most of the Lp(a) was taken up by the liver, followed by kidney and spleen. Lp(a) and asialo-Lp(a) were catabolized with apparent half-lives of 13.8 and 0.55 h respectively. Asialo-orosomucoide increased both half-lives significantly. In mice, the apparent half-life of Lp(a) was 4–6 h. Catabolism of native Lp(a) by wild-type mice was significantly faster compared with ASGPR− mice and there was a significantly greater accumulation of Lp(a) in the liver of ASGPR+ mice compared with ASGPR− mice. The catabolism of asialo-Lp(a) in ASGPR− mice was 8-fold faster when compared with native Lp(a) in wild-type mice. Transfected COS-7 cells expressing functional ASGPR showed approx. 5-fold greater binding and 2-fold faster degradation of native Lp(a) compared with control cells. Our results for the first time demonstrate a physiological function of ASGPR in the catabolism of Lp(a).

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Ecto-Nucleotide Triphosphate Diphosphohydrolase-2 (NTPDase2) Deletion Increases Acetaminophen-Induced Hepatotoxicity

International Journal of Molecular Sciences ◽

10.3390/ijms21175998 ◽

2020 ◽

Vol 21 (17) ◽

pp. 5998

Author(s):

Linda Feldbrügge ◽

Katrin Splith ◽

Ines Kämmerer ◽

Sandra Richter ◽

Anna Riddermann ◽

...

Keyword(s):

Liver Injury ◽

Liver Toxicity ◽

Wild Type ◽

Protective Properties ◽

Hepatic Expression ◽

Markers Of Inflammation ◽

Acute Necrotizing ◽

Portal Fibroblast ◽

Portal Fibroblasts

Ecto-nucleotidase triphosphate diphosphohydrolase-2 (NTPDase2) is an ecto-enzyme that is expressed on portal fibroblasts in the liver that modulates P2 receptor signaling by regulating local concentrations of extracellular ATP and ADP. NTPDase2 has protective properties in liver fibrosis and may impact bile duct epithelial turnover. Here, we study the role of NTPDase2 in acute liver injury using an experimental model of acetaminophen (APAP) intoxication in mice with global deletion of NTPDase2. Acute liver toxicity was caused by administration of acetaminophen in wild type (WT) and NTPDase2-deficient (Entpd2 null) mice. The extent of liver injury was compared by histology and serum alanine transaminase (ALT). Markers of inflammation, regeneration and fibrosis were determined by qPCR). We found that Entpd2 expression is significantly upregulated after acetaminophen-induced hepatotoxicity. Entpd2 null mice showed significantly more necrosis and higher serum ALT compared to WT. Hepatic expression of IL-6 and PDGF-B are higher in Entpd2 null mice. Our data suggest inducible and protective roles of portal fibroblast-expressed NTPDase2 in acute necrotizing liver injury. Further studies should investigate the relevance of these purinergic pathways in hepatic periportal and sinusoidal biology as such advances in understanding might provide possible therapeutic targets.

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Liver asialoglycoprotein receptor levels correlate with severity of alcoholic liver damage in rats

Journal of Applied Physiology ◽

10.1152/japplphysiol.00375.2003 ◽

2004 ◽

Vol 96 (1) ◽

pp. 76-80 ◽

Cited By ~ 20

Author(s):

Carol A. Casey ◽

Benita L. McVicker ◽

Terrence M. Donohue ◽

Melinda A. McFarland ◽

Robert L. Wiegert ◽

...

Keyword(s):

Liver Injury ◽

Oral Administration ◽

Liver Damage ◽

Medium Chain Triglyceride ◽

Asialoglycoprotein Receptor ◽

Mrna Levels ◽

Liver Pathology ◽

Medium Chain ◽

Ethanol Group ◽

Liver Changes

It has been demonstrated that the oral administration of ethanol (Lieber-DeCarli liquid diet) to rats results in a decreased expression and content of the asialoglycoprotein receptor (ASGP-R) in the resultant fatty liver. In the present study, we wanted to determine whether the extent of impaired receptor content was correlated with the severity of liver pathology by using the intragastric feeding model. When ASGP-R protein and mRNA levels were measured in animals infused with ethanol or dextrose in the presence of fish oil (FO) or medium-chain triglyceride as the source of fat, more significant impairments to the ASGP-R were observed in the FO-ethanol group compared with the medium-chain triglyceride-ethanol group. Furthermore, only the FO-ethanol group showed pathological liver changes. These results demonstrate that a correlation exists between the progression of alcohol-associated liver injury, as defined by the severity of liver pathology, and an ethanol-induced decline in ASGP-R content.

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The chemokine scavenging receptor D6 limits acute toxic liver injury in vivo

Biological Chemistry ◽

10.1515/bc.2009.119 ◽

2009 ◽

Vol 390 (10) ◽

Cited By ~ 22

Author(s):

Marie-Luise Berres ◽

Christian Trautwein ◽

Mirko Moreno Zaldivar ◽

Petra Schmitz ◽

Katrin Pauels ◽

...

Keyword(s):

Liver Injury ◽

Liver Damage ◽

Immune Modulation ◽

Scavenger Receptor ◽

Wild Type ◽

Protein Levels ◽

Inflammatory Chemokines ◽

Toxic Liver Injury ◽

Acute Toxic

Abstract The chemokine decoy receptor D6 is a promiscuous chemokine receptor lacking classical signaling functions. It negatively regulates inflammation by targeting CC chemokines to cellular internalization and degradation. Here we analyze the function of D6 in acute CCl4-induced liver damage in constitutive D6-/- and wild-type mice. The degree of liver injury was assessed by liver histology, serum transaminases, IL-6, and TNFα mRNA expression. Protein levels of D6 ligands (CCL2, CCL3, CCL5) and the non-D6-ligand CXCL9 within the livers were determined by ELISAs. The intrahepatic infiltration of immune cells was characterized by FACS. Genetic deletion of D6 led to prolonged liver damage after acute CCl4 administration. The augmented liver damage in D6-/- mice was associated with increased protein levels of intrahepatic inflammatory chemokines CCL2, CCL3, and CCL5 after 48 h, whereas CXCL9 was not different between knockout and wild-type mice. Functionally, increased intra-hepatic CC chemokine concentrations led to increased infiltration of CD45+ leukocytes, which were mainly identified as T and NK cells. In conclusion, the chemokine scavenger receptor D6 has a non-redundant role in acute toxic liver injury in vivo. These results support the importance of post-translational chemokine regulation and describe a new mechanism of immune modulation within the liver.

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Desialylated Platelets Are Cleared From the Circulation by the Hepatic Asialoglycoprotein Receptor,

Blood ◽

10.1182/blood.v118.21.3257.3257 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3257-3257

Author(s):

Renata Grozovsky ◽

Silvia Giannini ◽

Karin M. Hoffmeister

Keyword(s):

Bone Marrow ◽

Conflicts Of Interest ◽

Fold Increase ◽

Asialoglycoprotein Receptor ◽

Regulatory Mechanisms ◽

Wild Type ◽

Cell Counts ◽

Blood Cell Counts ◽

Terminal Galactose

Abstract Abstract 3257 The regulatory mechanisms of platelet homeostasis remain elusive. We investigated here the role of hepatic asialoglycoprotein receptor (a.k.a. Ashwell-Morell receptor) in platelet clearance. Mice lacking the hepatic asialoglycoprotein receptor Asgpr2 subunit had increased platelet survivals (T1/2 = 49.5±2h) when compared to wild type (WT, T1/2 = 31±4h) mice. Consequently, Asgpr2−/− mice had platelet counts increased by ∼20%, compared to WT, with increased terminal galactose exposure, as demonstrated using the galactose specific lectin RCA1. Bone marrow and spleen megakaryocyte numbers were reduced by ∼15% and ∼20% in Asgpr2−/− mice, compared to WT mice. Sialidase (NA, Clostidium perfringens, 50mU/mice) maximally desialylated circulating platelets when injected intravenously, as evidenced by increased RCA1 binding. Sialidase injection resulted in a ∼60% depletion of circulating platelets after 24h in Asgpr2−/− mice, compared to >90% in WT mice, indicating that desialylated platelets were partially removed by Asgpr1/2. In contrast to platelets, red blood cell counts were unaffected by sialidase treatment. Sialidase injection for 72h resulted in a 2.3-fold and 1.2-fold increase in megakaryocyte numbers in the spleen and bone marrow of WT mice, respectively, but not in Asgpr2−/− mice. In contrast to sialidase treatment, injections of rabbit anti-mouse platelet serum (RAMPS) depleted >95% of circulating platelets and increased by 70% bone marrow, but not spleen MK numbers in both WT and Asgpr2−/− mice. The data shows that removal of desialylated, i.e, senescent, platelets by the hepatic Ashwell-Morell receptor differs to that of antibody-mediated platelet clearance. Disclosures: No relevant conflicts of interest to declare.

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