Kupffer Cells In Mice Research Articles

Impact of three myeloid-derived suppressor cell subsets on Kupffer cells in HCC-bearing mice

Impact of three myeloid-derived suppressor cell subsets on Kupffer cells in HCC-bearing mice

Kupffer Cell Transplantation in Mice for Elucidating Monocyte/Macrophage Biology and for Potential in Cell or Gene Therapy

Kupffer cells (KC) play major roles in immunity and tissue injury or repair. Because recapitulation of KC biology and function within liver will allow superior insights into their functional repertoire, we studied the efficacy of the cell transplantation approach for this purpose. Mouse KC were isolated from donor livers, characterized, and transplanted into syngeneic recipients. To promote cell engraftment through impairments in native KC, recipients were preconditioned with gadolinium chloride. The targeting, fate, and functionality of transplanted cells were evaluated. The findings indicated that transplanted KC engrafted and survived in recipient livers throughout the study period of 3 months. Transplanted KC expressed macrophage functions, including phagocytosis and cytokine expression, with or without genetic modifications using lentiviral vectors. This permitted studies of whether transplanted KC could affect outcomes in the context of acetaminophen hepatotoxicity or hepatic ischemia-reperfusion injury. Transplanted KC exerted beneficial effects in these injury settings. The benefits resulted from cytoprotective factors including vascular endothelial growth factor. In conclusion, transplanted adult KC were successfully targeted and engrafted in the liver with retention of innate immune and tissue repair functions over the long term. This will provide excellent opportunities to address critical aspects in the biogenesis, fate, and function of KC within their native liver microenvironment and to develop the cell and gene therapy potential of KC transplantation.

Kupffer cells-dependent inflammation in the injured liver increases recruitment of mesenchymal stem cells in aging mice.

Mesenchymal stem cells (MSCs) repair tissue injury and may be used to treat immune associated diseases. In carbon tetrachloride (CCl4)-induced liver injury murine model, we administered MSCs. When MSCs were transmitted to young and old mice with liver injury, more MSCs were recruited in old mice. In old mice, inflammation, characterized by TNF-α and IL-6, was increased due to hyper-activation and hyper-function of Kupffer cells. Blocking Kupffer cells decreased MSCs migration in old mice. In vitro, Kupffer cells isolated from old mice secreted more inflammatory cytokines and chemokines. Thus, hyper-activation of Kupffer cells in old mice increased recruitment of MSCs after their therapeutic administration.

The effects of either resveratrol or exercise on macrophage infiltration and switching from M1 to M2 in high fat diet mice

[Purpose] The aim of this study was to compare the effectiveness of either resveratrol supplementation or exercise training on macrophage infiltration and switching from M1 to M2 kupffer cells in high fat diet mice. [Methods] C57BL/6 mice were separated into 5 groups: normal diet (ND; n = 6), high-fat diet (HD; n = 6), high-fat diet with resveratrol (HR; n = 6), high-fat diet with exercise (HE; n = 6) or high-fat diet with resveratrol and exercise (HRE; n = 6). Resveratrol supplementation mice were orally gavaged with resveratrol (25mg/kg of body weight) dissolved in 50% propylene glycol. Exercise mice ran on a treadmill at 12-20 m/min for 30-60 min/day, 5 times/week for 12 weeks. [Results] After 12 weeks of intervention, the liver was analyzed. F4/80 expression was evaluated by western blot while CD11c and CD163 mRNA expressions were evaluated by RT-PCR. The weights of the body and liver were significantly increased in the HD and HR group compared to the ND group (p < 0.01). However, the weights were most effectively reduced in the HE and HRE groups compared to the HD group (p < 0.05). The macrophage marker, F4/80 expression was significantly lower in the HE and HRE groups compared to the HD group (p < 0.05). mRNA expression of the M1 macrophage marker, CD11c, in the HD group was significantly increased compared to the ND group (p < 0.01). mRNA expression of the M2 macrophage specific marker, CD163, in the HE and HRE groups were significantly increased compared to the HD group (p < 0.05). The mRNA expressions of TLR4, ICAM-1 and VCAM-1, which induce pro-inflammatory cytokine production, were strongly decreased in the HR, HE, and HRE groups compared to the HD group. [Conclusion] These results suggest that moderate exercise training inhibits macrophage infiltration and up regulation of CD163 expression. However, resveratrol supplementation is not enough to ameliorate obesity-induced macrophage infiltration and switching. Keywords: obese, exercise, resveratrol, macrophage infiltration, switching

Increasing intestinal reactive oxygen species reverses diabetes-induced inflammation (MUC2P.928)

Abstract Systemic inflammation appears to persist in diabetic patient. To examine the role of reactive oxygen species (ROS) of intestine in DM-induced inflammation, streptozotocin (STZ)-induced diabetes and Ins2Akita (Ins2Akita mutation mutant) mice were used. STZ mice demonstrated a significant decrease of Lacobacilli as well as ROS production and a marked increase of p-JNK as well as iNOS expression in the intestinal mucosa. Oral supplementation of fructooligosaccharides (FOS) or dead Lacobacilli increased the production of ROS of intestine and decreased IL-1β expression of Kupffer cells in STZ and Ins2Akita mice. Feeding of L-NAME, an iNOS inhibitor, but not D-NAME increased the production of ROS of intestinal mucosa and decreased endotoxin in portal vein and IL-1β expression of Kupffer cells in STZ mice. Oral feeding of N-Acetylcysteine, a ROS scavenger, decreased ROS production and inhibited the effects of FOS as well as L-NAME on reversing DM-induced ICAM expression of liver. Using STZ JNK1-/- and Ins2Akita JNK1-/- mice to reverse DM-induced pJNK expression of intestinal mucosa induced a significant decrease of IL-1β expression of Kupffer cells and ICAM expression of liver. Collectively, diabetes induces systemic inflammation through decreasing ROS production and increasing pJNK expression of intestine. Increasing intestinal ROS production could reverse diabetes-induced systemic inflammation.

Abstract 698: Increases Reticulated Platelets due to Enhanced Proliferation and Expansion of Bone Marrow Megakaryocyte Progenitors Accelerates Atherosclerosis in Diabetes

Diabetes (type 1 &amp; 2) is a major risk factor for cardiovascular disease which represents the major cause of mortality in this group. Patients with diabetes present with reticulated thrombocytosis (increased immature platelets), which lower the efficacy of current anti-platelet therapies. We hypothesized that the reticulated thrombocytosis observed in people with diabetes plays an important role in atherogenesis. Thus, we investigated the mechanisms contributing to increased reticulated platelets in diabetes. Streptozotocin induced diabetic mice had significantly higher level (2-fold) of reticulated platelets. This was paralleled by an increase in the population of megakaryocyte progenitors (MkPs) and megakaryocytes in the bone marrow (BM). Diabetes caused an increase in circulating thrombopoietin (TPO) without altering the expression of the TPO receptor (c-MPL) on any of the BM progenitor cells or circulating platelets. TPO expression is generally upregulated by Kupffer cell derived interleukin-6 (IL-6). We found more Kupffer cells in the liver of diabetic mice which expressed higher levels of cell surface RAGE (Receptor for Advanced Glycated End-products) and produced more IL-6. Depletion of Kupffer cells using clodronate liposomes normalized the levels of total and reticulated platelets along with MkPs in the BM. Rage-/- BM transplantation (BMT) into mice that were then made diabetic were protected from diabetes-induced thrombocytosis and MkP expansion. Kupffer cells from diabetic Rage-/- BMT mice failed to express IL-6 and plasma TPO levels remained similar to the non-diabetic mice. IL-6-/- BMT mice were also protected from diabetes-induced thrombocytosis. Together, we identified a role for RAGE in the liver Kupffer cells of diabetic mice that triggers IL-6 expression, which in-turn promotes TPO production. TPO then enhances proliferation and expansion of MkPs in the BM, resulting in an increase in the abundance of reticulated platelets. Using BM from a genetic model (Bcl-xPlt20) of low platelets transplanted into Ldlr+/- mice we found that lower circulating platelets resulted in smaller atherosclerotic lesions. Our data suggests that increased platelet production contributes to accelerated atherogenesis in diabetes.

Su1803 Dietary Glycine Improves Impaired Glucose Tolerance by Modulating Polarization of Kupffer Cells in Diabetic KK-aY Mice

Su1803 Dietary Glycine Improves Impaired Glucose Tolerance by Modulating Polarization of Kupffer Cells in Diabetic KK-aY Mice

Acquiring Kupffer Cells in Mice Using a MACS-Based Method

ObjectiveThis study sought to establish a new method to isolate Kupffer cells (KCs) by magnetic activated cell sorting (MACS). MethodsNonparenchymal cells were acquired from C57BL/6 mice livers by a perfusion system in vivo and then stained with F4/80+ fluorescein isothiocyanate and CD11c− phycoerythrin antibodies. After incubating with immunomagnetic beads, F4/80+CD11c− KCs were obtained by MACS selection. The purity was evaluated by flow cytometry, and the morphological features and vitality were analyzed in in vitro cultures. ResultsCompared with traditional methods, acquiring KCs by MACS was characterized by economy, efficiency, and high purity. The F4/80+CD11c− KCs cultured in vitro also showed the typical adherent shape and excellent phagocytic ability. ConclusionsWith the 2-step method using immunomagnetic beads, we provide a new method by which KCs can be obtained from mouse liver with high purity and distinct phenotype of F4/80+ CD.

Extracellular ATP induces P2X7 receptor activation in mouse Kupffer cells, leading to release of IL-1β, HMGB1, and PGE2, decreased MHC class I expression and necrotic cell death

Kupffer cells, which are resident macrophages in liver, can produce various cytokines and chemokines that induce hepatitis and liver fibrosis. It is suggested that extracellular ATP-induced activation of macrophage P2X7 receptor plays an important role in inflammation via release of pro-inflammatory mediators, but the role of P2X7 receptor in Kupffer cells remains unclear. Here, we show that activation of P2X7 receptor in Kupffer cells causes multiple inflammatory responses, using the clonal mouse Kupffer cell line (KUP5) that we previously established. Treatment of LPS-primed Kupffer cells with 3 mM ATP induced Ca2+ influx, non-selective large pore formation, activation of MAPK, cell lysis, IL-1β release, prostaglandin E2 (PGE2) release, high mobility group box1 (HMGB1) release, and major histocompatibility complex (MHC) class I shedding. These events were significantly suppressed by pretreatment with P2X7 antagonist A438079, indicating involvement of P2X7 receptor activation in these inflammatory responses. Our results suggest that extracellular ATP-induced activation of P2X7 receptor of Kupffer cells plays multiple roles in the inflammatory response in liver. P2X7 receptor might be a new therapeutic target for treatment of liver diseases.

Effects of combined alcohol and anti-HIV drugs on cellular stress responses in primary hepatocytes and hepatic stellate and kupffer cells.

Certain anti-HIV drugs alone or in combination are often associated with liver damages, which are frequently worsened by alcohol consumption. We previously found an endoplasmic reticulum (ER) stress mechanism for the drug- and alcohol-induced hepatic injuries in animal models and in vitro hepatocytes. However, it is unknown whether anti-HIV drugs and alcohol induce similar cellular stress responses and injuries in liver nonparenchymal cells. Primary mouse hepatocytes (PMH), kupffer cells (KC), and hepatocellular stellate cells (HSC) were freshly isolated from mouse liver and treated with DMSO, stress-inducing pharmaceutical agents, alcohol alone, or in combination with antiviral ritonavir (RIT), lopinavir (LOP), or efavirenz (EFV). Expression of cellular stress markers, protein colocalization, and cell death were analyzed with immunoblotting, immunocytochemistry, and positive double staining with Sytox green and Hoechst blue, respectively. Expression of the ER stress markers of BiP, CHOP, and SERCA and the autophagy marker LC3 was significantly changed in PMH in response to combined alcohol, RIT, and LOP, which was companied by increased cell death compared with control. In contrast, although pharmaceutical agents induced ER stress and cell death, no significant ER stress or cell death was found in KC treated with alcohol, RIT, LOP, and EFV singly or in combination. In HSC, alcohol, RIT, LOP, or EFV induced BiP, but not CHOP, SERCA, or cell death compared with vehicle control. Further in PMH, RIT and LOP or in combination with alcohol-induced dose-dependent inhibition of β-actin. Inhibition of β-actin by RIT and LOP was companied with an inhibited nuclear expression of the antioxidant response regulator Nrf2 and reduced GST downstream of Nrf2. Ascorbic acid treatment reduced the alcohol-, RIT-, and LOP-induced cell death. The data suggest for the first time that sensitivities of hepatocytes and nonparenchymal cells to alcohol and anti-HIV drugs in vitro are different in terms of cellular stress response and cell death injury. Oxidative stress mediated by Nrf2 contributes to the alcohol- and drug-induced toxicity in the hepatocytes.

MiR-146a ameliorates liver ischemia/reperfusion injury by suppressing IRAK1 and TRAF6.

A critical role of the Toll-like receptor(TLR) and its downstream molecules, including IL-1 receptor-associated kinase 1(IRAK1) and tumor necrosis factor receptor– associated factor 6(TRAF6), in the pathogenesis of liver ischemia/reperfusion (I/R) injury has been documented. Recently a microRNA, miR-146a, was identified as a potent negative regulator of the TLR signaling pathway. In this study, we investigated the role of miR-146a to attenuate TLR signaling and liver I/R injury in vivo and in vitro. miR-146a was decreased in mice Kupffer cells following hepatic I/R, whereas IRAK1 and TRAF6 increased. Overexpression of miR-146a directly decreased IRAK1 and TRAF6 expression and attenuated the release of proinflammatory cytokines through the inactivation of NF-κB P65 in hypoxia/reoxygenation (H/R)-induced macrophages, RAW264.7 cells. Knockdown experiments demonstrated that IRAK1 and TRAF6 are two potential targets for reducing the release of proinflammatory cytokines. Moreover, co-culture assays indicated that miR-146a decreases the apoptosis of hepatocytes after H/R. In vivo administration of Ago-miR-146a, a stable version of miR-146a in vivo, protected against liver injury in mice after I/R via inactivation of the TLR signaling pathway. We conclude that miR-146a ameliorates liver ischemia/reperfusion injury in vivo and hypoxia/reoxygenation injury in vitro by directly suppressing IRAK1 and TRAF6.

Purinergic signaling via P2X7 receptor mediates IL-1β production in Kupffer cells exposed to silica nanoparticle

There is extensive evidence that nanoparticles (NPs) cause adverse effects in multiple organs, including liver, though the mechanisms involved remain to be fully established. Kupffer cells are macrophages resident in the liver, and play important roles in liver inflammation induced by various toxic agents, including lipopolysaccharide (LPS). Interleukin-1 (IL-1) family members IL-1α,β are released from LPS-primed macrophages exposed to NPs, including silica NPs (SNPs), via activation of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 inflammasomes. Here, we investigated the mechanism of production of IL-1β via activation of inflammasomes in mouse Kupffer cell line KUP5, focusing on the role of purinergic signaling via P2X7 receptor.IL-1β production by LPS-primed KUP5 cells exposed to SNPs was increased dose-dependently, and was greatest in response to SNPs with a diameter of 30nm (SNP30), as compared with 70-nm and 300-nm SNPs (SNP70 and SNP300). ATP release was also highest in cells exposed to SNP30. Treatment of LPS-primed KUP5 cells with ATP also induced a high level of IL-1β production, similar to that induced by SNP30. IL-1β production was significantly inhibited by apyrase (an ecto-nucleotidase) and A438079 (a P2X7 antagonist/ATP-release inhibitor). Production of reactive oxygen species (ROS) was confirmed in cells exposed to SNP30.In conclusion, ATP released from P2X7 receptor in response to stimulation of KUP5 cells with SNP30 induces ROS production via cell-membrane NADPH oxidase. The ROS causes activation of inflammasomes, leading to caspase-1-dependent processing of IL-1β.

Knockdown of MicroRNA-155 in Kupffer Cells Results in Immunosuppressive Effects and Prolongs Survival of Mouse Liver Allografts

Our previous studies have shown that Kupffer cells (KCs) play a crucial role in postoperative pathologic changes. Recent reports have demonstrated that microRNA-155 (miR-155) is associated with inflammation and upregulation of proinflammatory mediators in the peripheral blood and allografts of transplant patients. However, the precise mechanism for this remains unknown. KCs isolated from BALB/c mice were transfected with miR-155 mimic or inhibitor. Levels of suppressor of cytokine signaling 1/Janus kinase/signal transducer and activator of transcription (SOCS1/JAK/STAT) proteins and surface molecules (MHC-II, CD40, and CD86) were then measured. T-cell proliferation and apoptosis were evaluated in mixed lymphocyte reactions. Orthotopic liver transplantation was performed in mice after miR-155 short hairpin RNA lentivirus treatment, and postoperative survival, liver function and histology, and mRNA and protein expression were analyzed. miR-155 knockdown in KCs decreased MHC-II, CD40, and CD86 expression, suppressed antigen-presenting function, and affected SOCS1/JAK/STAT inflammatory pathways. In addition, KCs transfected with miR-155 inhibitor and cocultured with T lymphocytes showed reduced T-cell responses but a greater number of apoptotic T cells. Finally, miR-155 suppression in graft liver prolonged liver allograft survival and improved liver function. The changes were closely associated with the levels of T helper 1 and 2 (Th1/Th2) cytokines and T-cell apoptosis, but a direct mechanistic link in vivo was not established. These data suggest miR-155 regulates the balance of Th1/Th2 cytokines and the maturation and function of KCs in mice. miR-155 repression in KCs positively regulates KC function toward immunosuppression and prolongs liver allograft survival.

Acyl-CoA:cholesterol acyltransferase 1 mediates liver fibrosis by regulating free cholesterol accumulation in hepatic stellate cells

Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes the conversion of free cholesterol (FC) to cholesterol ester, which prevents excess accumulation of FC. We recently found that FC accumulation in hepatic stellate cells (HSCs) plays a role in progression of liver fibrosis, but the effect of ACAT1 on liver fibrosis has not been clarified. In this study, we aimed to define the role of ACAT1 in the pathogenesis of liver fibrosis. ACAT1-deficient and wild-type mice, or Toll-like receptor 4 (TLR4)(-/-)ACAT1(+/+) and TLR4(-/-)ACAT1(-/-) mice were subjected to bile duct ligation (BDL) for 3 weeks or were given carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis. ACAT1 was the major isozyme in mice and human primary HSCs, and ACAT2 was the major isozyme in mouse primary hepatocytes and Kupffer cells. ACAT1 deficiency significantly exaggerated liver fibrosis in the mouse models of liver fibrosis, without affecting the degree of hepatocellular injury or liver inflammation, including hepatocyte apoptosis or Kupffer cell activation. ACAT1 deficiency significantly increased FC levels in HSCs, augmenting TLR4 protein and downregulating expression of transforming growth factor-β (TGFβ) pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor), leading to sensitization of HSCs to TGFβ activation. Exacerbation of liver fibrosis by ACAT1 deficiency was dependent on FC accumulation-induced enhancement of TLR4 signaling. ACAT1 deficiency exaggerates liver fibrosis mainly through enhanced FC accumulation in HSCs. Regulation of ACAT1 activities in HSCs could be a target for treatment of liver fibrosis.

An efficient method to isolate and culture mouse Kupffer cells

Kupffer cells (KCs) play an essential role in the physiological and pathological functions of the liver. Although the isolation methods of KCs have been well-described, most of them are sophisticated and time-consuming. In addition, these methods are mainly used for isolating the KCs of the human and rat. In this study, a three-step procedure was applied to isolate KCs in sufficient number and purity from mouse liver, including the techniques of enzymatic tissue treatment, gradient centrifugation, and selective adherence. F4/80 immunofluorescence and flow cytometry were used for cell identification. The combination method resulted in a satisfactorily high yield of 5–6×106 KCs per liver, over 92.0% positive for F4/80 and 98.5% viable cells. After 24h of culturing, the KCs showed typical macrophage morphologic features such as irregular shape, transparent cytoplasm and kidney-like nucleus. The phagocytic assay showed that the isolated cells exhibited strong phagocytosis activity. The KCs we isolated were functionally intact and exhibited a concentration dependent TNF-α production induced by LPS. The method we described is an effective method to isolate mouse KCs in high purity and yield, which consuming fewer collagenase and time without altering the functional capacity of the KCs.

The surface carbohydrates of the Echinococcus granulosus larva interact selectively with the rodent Kupffer cell receptor

The larvae of the cestodes belonging to the genus Echinococcus dwell primarily in mammalian liver. They are protected by the laminated layer (LL), an acellular mucin-based structure. The glycans decorating these mucins constitute the overwhelming majority of molecules exposed by these larvae to their hosts. However, their decoding by host innate immunity has not been studied. Out of 36 mammalian innate receptors with carbohydrate-binding domains, expressed as Fc fusions, only the mouse Kupffer cell receptor (KCR; CLEC4F) bound significantly to the Echinococcus granulosus LL mucins. The receptor also bound the Echinococcus multilocularis LL. Out of several synthetic glycans representing Echinococcus LL structures, the KCR bound strongly in particular to those ending in Galα1-4Galβ1-3 or Galα1-4Galβ1-4GlcNAc, both characteristic LL carbohydrate motifs. LL carbohydrates may be optimized to interact with the KCR, expressed only in liver macrophages, cells known to contribute to the tolerogenic antigen presentation that is characteristic of this organ.

A Transcriptomic Network Identified in Uninfected Macrophages Responding to Inflammation Controls Intracellular Pathogen Survival

SummaryIntracellular pathogens modulate host cell function to promote their survival. However, in vitro infection studies do not account for the impact of host-derived inflammatory signals. Examining the response of liver-resident macrophages (Kupffer cells) in mice infected with the parasite Leishmania donovani, we identified a transcriptomic network operating in uninfected Kupffer cells exposed to inflammation but absent from Kupffer cells from the same animal that contained intracellular Leishmania. To test the hypothesis that regulated expression of genes within this transcriptomic network might impact parasite survival, we pharmacologically perturbed the activity of retinoid X receptor alpha (RXRα), a key hub within this network, and showed that this intervention enhanced the innate resistance of Kupffer cells to Leishmania infection. Our results illustrate a broadly applicable strategy for understanding the host response to infection in vivo and identify Rxra as the hub of a gene network controlling antileishmanial resistance.

Substance P participates in immune-mediated hepatic injury induced by concanavalin A in mice and stimulates cytokine synthesis in Kupffer cells

Studies have indicated that the immune system plays a pivotal role in hepatitis. Substance P (SP) has been shown to modulate the immune response. In order to investigate the role of SP in liver injury and to determine whether it leads to pro-inflammatory signaling, we established a mouse model of hepatic injury induced by concanavalin A (ConA). We also exposed mouse Kupffer cells (KCs) to SP in vitro. Cytokine and SP levels in liver homogenates were detected using enzyme-linked immunosorbent assay (ELISA) and the protective effects of L-703,606 were evaluated through serological and histological assessments. Neurokinin-1 receptor (NK-1R) expression was evaluated by immunofluorescence and quantitative polymerase chain reaction (PCR). The levels of SP, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in the ConA-treated mice and the levels of ALT and AST were markedly reduced by L-703,606-pretreatment. Liver injury was significantly reduced by treatment with L-703,606. The mouse KCs expressed NK-1R and SP increased NK-1R mRNA expression. Furthermore, NK-1R blockade eliminated the effect of SP on NK-1R mRNA expression. The cytokine levels exhibited a substantial increase in the SP-pretreated KCs compared with the KCs that were cultured in control medium. The inter-leukin (IL)-6 and tumor necrosis factor (TNF)-α levels in the L-703,606-pretreated KCs were significantly lower compared with those in the SP-pretreated KCs. Our study suggests that neurogenic inflammation induced by SP plays an important role in hepatitis. Mouse KCs express NK-1R and SP increases NK-1R mRNA expression. SP enhances IL-6 and TNF-α secretion and an NK-1R antagonist inhibits this secretion.

Platelets and Kupffer cells: partners in liver regeneration: Commentary on “Human platelets promote liver regeneration with Kupffer cells in SCID mice”

Platelets and Kupffer cells: partners in liver regeneration: Commentary on “Human platelets promote liver regeneration with Kupffer cells in SCID mice”

Nuclear receptor atlas of female mouse liver parenchymal, endothelial, and Kupffer cells

The liver consists of different cell types that together synchronize crucial roles in liver homeostasis. Since nuclear receptors constitute an important class of drug targets that are involved in a wide variety of physiological processes, we have composed the hepatic cell type-specific expression profile of nuclear receptors to uncover the pharmacological potential of liver-enriched nuclear receptors. Parenchymal liver cells (hepatocytes) and liver endothelial and Kupffer cells were isolated from virgin female C57BL/6 wild-type mice using collagenase perfusion and counterflow centrifugal elutriation. The hepatic expression pattern of 49 nuclear receptors was generated by real-time quantitative PCR using the NUclear Receptor Signaling Atlas (NURSA) program resources. Thirty-six nuclear receptors were expressed in total liver. FXR-α, EAR2, LXR-α, HNF4-α, and CAR were the most abundantly expressed nuclear receptors in liver parenchymal cells. In contrast, NUR77, COUP-TFII, LXR-α/β, FXR-α, and EAR2 were the most highly expressed nuclear receptors in endothelial and Kupffer cells. Interestingly, members of orphan receptor COUP-TF family showed a distinct expression pattern. EAR2 was highly and exclusively expressed in parenchymal cells, while COUP-TFII was moderately and exclusively expressed in endothelial and Kupffer cells. Of interest, the orphan receptor TR4 showed a similar expression pattern as the established lipid sensor PPAR-γ. In conclusion, our study provides the most complete quantitative assessment of the nuclear receptor distribution in liver reported to date. Our gene expression catalog suggests that orphan nuclear receptors such as COUP-TFII, EAR2, and TR4 may be of significant importance as novel targets for pharmaceutical interventions in liver.