Heme oxygenase-1 protects donor livers from ischemia/reperfusion injury:The role of Kupffer cells

AIM:To examine whether heme oxygenase (HO)-1 overexpression would exert direct or indirect effects on Kupffer cells activation, which lead to aggravation of reperfusion injury.METHODS: Donors were pretreated with cobalt protoporphyrin (CoPP) or zinc protoporphyrin (ZnPP), HO-1 inducer and antagonist, respectively. Livers were stored at 4℃ for 24 h before transplantation. Kupffer cells were isolated and cultured for 6 h after liver reperfusion.RESULTS: Postoperatively, serum transaminases were significantly lower and associated with less liver injury when donors were pretreated with CoPP, as compared with the ZnPP group. Production of the cytokines tumor necrosis factor-α and interleukin-6 generated by Kupffer cells decreased in the CoPP group. The CD14 expression levels (RT-PCR/Western blots) of Kupffer cells from CoPP-pretreated liver grafts reduced.CONCLUSION: The study suggests that the potential utility of HO-1 overexpression in preventing ischemia/reperfusion injury results from inhibition of Kupffer cells activation.

Ron receptor-dependent gene regulation of Kupffer cells during endotoxemia

BACKGROUND: Ron receptor tyrosine kinase signaling in macrophages, including Kupffer cells and alveolar macrophages,suppresses endotoxin-induced proinflammatory cytokine/chemokine production. Further, we have also identified genes from Ron replete and Ron deplete livers that were differentially expressed during the progression of liver inflammation associated with acute liver failure in mice by microarray analyses.While important genes and signaling pathways have been identified downstream of Ron signaling during progression of inflammation by this approach, the precise role that Ron receptor plays in regulating the transcriptional landscape in macrophages, and particular in isolated Kupffer cells, has still not been investigated.METHODS: Kupffer cells were isolated from wild-type(TK+/+)and Ron tyrosine kinase deficient(TK-/-) mice. Ex vivo, the cells were treated with lipopolysaccharide(LPS) in the presence or absence of the Ron ligand, hepatocyte growth factor-like protein(HGFL). Microarray and qRT-PCR analyses were utilized to identify alterations in gene expression between genotypes.RESULTS: Microarray analyses identified genes expressed differentially in TK+/+ and TK-/- Kupffer cells basally as well as after HGFL and LPS treatment. Interestingly, our studies identified Mefv, a gene that codes for the anti-inflammatory protein pyrin, as an HGFL-stimulated Ron-dependent gene.Moreover, lipocalin 2, a proinflammatory gene, which is induced by LPS, was significantly suppressed by HGFL treatment.Microarray results were validated by qRT-PCR studies on Kupffer cells treated with LPS and HGFL.CONCLUSION: The studies herein suggest a novel mechanism whereby HGFL-induced Ron receptor activation promotes the expression of anti-inflammatory genes while inhibiting genes involved in inflammation with a net effect of diminished inflammation in macrophages.

Donor denervation and elimination of Kupffer cells affect expression of P-selectin and ICAM-1 in liver graft

BACKGROUND: The non-function and dysfunction of primary liver graft likely involves dependence on Kupffer cells and hepatic innervation. The present experiment was designed to study the expression of P-selectin and intercellular adhesion molecule-1 (ICAM-1) mRNA in liver graft and to elucidate the role of Kupffer cells and the sympathetic nerve of the liver in down-regulating this expression. METHODS: Donor rats were given hexamethonium, a sympathetic ganglionic blocking agent, and/or gadolinium chloride, an inhibitor of Kupffer cells. Then the changes of graft P-selectin and ICAM-1 mRNA expression were measured after liver transplantation. RESULTS: The expressions of P-selectin and ICAM-1 mRNA were increased after liver transplantation, and down-regulated by liver denervation and elimination of Kupffer cells. CONCLUSIONS: Live donor denervation and elimination of Kupffer cells down-regulated the expressions of P-selectin and ICAM-1 mRNA in grafts. This may decrease graft ischemia/reperfusion injury.

Kupffer cells contribute to concanavalin A-induced hepatic injury through a Th1 but not Th17 type response-dependent pathway in mice

BACKGROUND:Increasing evidence suggests that a close interaction of Kupffer cells with T cells plays a central role in concanavalin A-induced hepatic injury in mice,but the underlying mechanisms remain obscure.The present study aimed to determine the relative roles of Th1 and Th17 type responses in concanavalin A-induced hepatic injury in mice, and to investigate whether or not Kupffer cells contribute to hepatic injury via a Th1 or Th17 type response-dependent pathway. METHODS:Immune-mediated hepatic injury was induced in C57BL/6 mice by intravenous injection of concanavalin A. Kupffer cells were inactivated by pretreatment with gadolinium chloride 24 hours before the concanavalin A injection.The interferon-gamma(IFN-γ)and interleukin-17(IL-17)pathways were blocked by specific neutralizing antibodies.Hepatic injury was assessed using serum transferase activity and pathological analysis.Expression of inflammatory cytokines within the liver was detected by real-time polymerase chain reaction and immunohistochemistry. RESULTS:Neutralization of IFN-γsignificantly attenuated concanavalin A-induced hepatic injury.However,neutralization of IL-17 failed to suppress the injury.Inactivation of Kupffer cells by gadolinium chloride pretreatment protected against concanavalin A-induced injury and significantly reduced hepatic cytokine levels including TNF-α,IL-6 and IFN-γbut not IL-17.CONCLUSION:Our findings suggest that Kupffer cells contribute to concanavalin A-induced hepatic injury via a Th1 type response-dependent pathway and production of inflammatory cytokines including TNF-α,IL-6 and IFN-γ.

IN VITRO ANTI-HEPATOMA EFFECTS OF MONOCYTES AND KUPFFER CELLS ISOLATED FROM HEPATOMA PATIENTS AFTER TREATMENT WITH BIOLOGICAL IMMUNE STIMULANTS

Monocytes (MC), lymphocytes (LC) and Kupffer cells (KC) were isolated respectively from blood and surgical liver samples of patients suffering from he-patocellular carcinoma (HCC). 13 patients were given BCG, mixed bacterium vaccine (MBV) and human white blood cell interferon (IFN), the other 3 patients were not treated with any biological immune stimulants (BIS) and served as controls. The cytosta-tic and cytotoxic effects of MC and KC on human hepatoma SMMC-7721 (TC) were assayed in vitro and the numbers of T total (Tt), T helper (Th) and T suppressor (Ts) cells were counted using CD monoclonal antibody immunofluorescence. The results were as follows: (1) On the 7th day after the first administration of BIS, the cytostatic and cytotoxic effects of MC on TC showed obvious increase over pre-administration. The activity of BIS was 1 ?5 times as high as that in the controls. (2) After 3 administrations, the cytostatic effect of MC on TC increased to the normal level (84%), while the controls remained as before (45%). (3) On the 7th day after first administration, cytostatic and cytotoxic effects of KC on TC were 0.5 and 1 times higher respectively than those of the controls. (4) The numbers of Tt and Th of patients given BIS increased continuously; on the contrary Ts decreased in number. These results indicate that combined use of BCG, MBV and IFN can actively enhance the immune anti-hepatoma function of patients suffering from HCC.

A NEW METHOD OF ISOLATING KUPFFER CELLS FROM BIOPSY TISSUE OF RAT LIVER

The isolation of a high yield and purity of Kupffer cells has been reported in detail.1 This paper reports into the research about isolation Kupffer cells from biopsy tissue of liver. This method includes 5 important steps: (1) take fresh liver tissue, and mince with scissors. (2) spin at low speed to wash off red blood cells. (3) digest in collagenase for suitable time. (4) isolate Kupffer cells on a percoll density gradient. (5) cell charaterization was observed by N.S.E stain and peroxidatic activity with lumino-meter measurement and phagocytosis with latex beads.2.3

Inhibition of allogeneic T-cell response by Kupffer cells expressing indoleamine 2,3-dioxygenase

AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRNA and FasL mRNA in KC pretreated with IFN-γwere studied with real-time polymerase chain reaction(PCR).The catabolism of tryptophan by IDO from KC was analyzed by high performance liquid chromatography.Allogeneic T-cell response was used to confirm the inhibition of KC in vitro.The proliferation of lymphocytes was detected using[ 3 H]thymidine incorporation.Cell cycle and lymphocyte apoptosis were evaluated by flow cytometric assay. RESULTS:Real-time PCR revealed IDO mRNA and FasL mRNA expressions in KC pretreated with IFN-γ,and IDO catabolic effect was confirmed by a decrease in tryptophan and increase in kynurenine concentration. KC expressing IDO and FasL in BABL/c mice acquired the ability to suppress the proliferation of T-cells from C57BL/6,which could be blocked by addition of 1-methyl-tryptophan and anti-FasL antibody.KC expressing IDO could induce allogeneic T-cell apoptosisCONCLUSION:In addition to Fas/FasL pathway,IDO may be another mechanism for KC to induce immune tolerance.

The effect of lipopolysaccharides on the expression of CD14 and TLR4 in rat Kupffer cells

OBJECTIVE: To assess the effect of lipopolysaccharides (LPS) on the expression of CD14 and TLR4 in rat Kupffer cells (KCs). METHODS: In rat KCs induced by LPS, the changes of CD14 and TLR4 expression were measured by RT-PCR and immunohistochemistry, and the expressions of TNF-αmRNA, IL-6mRNA or the concentrations of TNF-α, IL-6 were estimated by in situ hybridization, radioimmunoassay, and others. RESULTS: The expressions of CD14 and TLR4 in KCs induced by LPS were markedly increased in a dose-dependent manner (10 mg/L-1μg/L) or in a time-dependent manner (0.5 h-24 h), with the peaked expression of CD14 at 3-6 hours. The expressions of CD14 and TLR4 in KCs stimulated by the active mediators from KCs which had been exposed to LPS for 1 hour were obviously increased. CONCLUSIONS: There is a close relationship between LPS or the active mediators from KCs induced by LPS and the expressions of CD14, TLR4. It is implied that the increase of TLR4, CD14 expression may be induced by LPS within 1--3 hours, and further increase of TLR4, CD14 expression may be correlated with the cytokines produced bv KCs.

Activation of NLRP3 Inflammasome via Drp1 Overexpression in Kupffer Cells Aggravates Ischemia-reperfusion Injury in Hepatic Steatosis

Background and Aims:Donors with fatty livers are considered to address the shortage of livers for transplantation,but those livers are particularly sensitive to ischemia-reperfusion injury(IRI),and an increased incidence of graft failure is observed.Kupffer cells account for 20–35%of liver nonparenchymal cells,and have been shown to participate in the process of IRI and inflammatory reactions of hepatic steatosis.NOD-like receptor thermal protein domain-associated protein 3(NLRP3)is an intracellular sensor activated by Kupffer cells to promote generation and participates in IRI.Dynamics-associated protein 1(Drp1)is one of the main proteins regulating mitochondrial division and exacerbates IRI by affecting mitochondrial dynamics.The mechanism of interaction of Kupffer cells with Drp1 and NLRP3 to aggravate IRI has not been clarified.Methods:A mouse model of hepatic steatosis was established by feeding the mice with a high-fat diet.In vitro experiments were performed using AML12 normal mouse liver cells and RAW264.7 mononuclear macrophage cells cultured in medium with palmitate and oleic acid.Western blotting and immunohistochemical(IHC)staining were used to detect the expression of NLRPP3 and Drp1 in IRI in the control and high-fat diet groups.The expression of F4/80+cells during IRI in hepatic steatosis was verified by IHC staining,and the role of NLRPP3 and Drp1 in Kupffer-cell mediated IRI was investigated by targeting Drp-1 inhibition.Results:Drp1 and NLRP3 expression was increased during IRI in hepatic steatosis,and the expression of Drp1 and NLRP3 were decreased after the elimination of Kupffer cells.That indicated Kupffer cells were involved in the process of IRI in hepatic steatosis through the action of Drp1 and NLRP3.After Drp1 inhibition,liver function was restored and NLRP3 expression level was reduced.Conclusions:Kupffer cells aggravated IRI in hepatic steatosis via NLRP3 and Drp1.Drp1 inhibitors might be useful as specific therapeutics to alleviate IRI in hepatic steatosis and may have promise in case of liver donor shortage.

Effects of Different Therapeutic Methods and Typical Recipes of Chinese Medicine on Activation of c-Jun N-terminal Kinase in Kupffer Cells of Rats with Fatty Liver Disease

Objective： To observe the effects of different therapeutic methods and the recipes of Chinese medicine （CM） on the activation of c-Jun N-terminal kinase （JNK） in Kupffer cells of rats with fatty liver disease and to explore the mechanisms of these therapeutic methods. Methods： By using a random number table, 98 rats were randomly divided into 7 groups： control group, model group, and 5 treatment groups, including soothing Liver （Gan） recipe group, invigorating Spleen （Pi） recipe group, dispelling dampness recipe group, promoting blood recipe group, and complex recipe group. Rats in the control group were fed with normal food and distilled water by gastric perfusion, while rats in the model group were fed with high-fat food and distilled spirits by gastric perfusion. Rats in the 5 treatment groups were fed with high-fat food and corresponding recipes by gastric perfusion. Twelve weeks later, all rats were sacrificed and liver tissues were stained for pathohistological observation. Kupffer cells were isolated from livers of rats to evaluate JNK and phospho-JNK expressions by Western blotting. Results： The grade of hepatic steatosis was higher in the model group than the control group （P〈0.05）. Compared with the model group, the grade of fatty degeneration in soothing Liver recipe group and invigorating Spleen recipe group were significantly ameliorated （P〈0.05）. Expressions of JNK and phospho-JNK in Kupffer cells were significantly higher in the model group than those in the control group （P〈0.05, P〈0.01）. Compared with the model group, expressions of JNK in all treatment groups decreased, especially in invigorating Spleen recipe group and promoting blood recipe group （P〈0.05）. Compared with the model group, expressions of phospho-JNK in all treatment groups declined significantly （P〈0.01）, especially in soothing Live recipe group and invigorating Spleen recipe group. Conclusions： The high expressions of JNK and phospho-JNK in Kupffer cells might play an important role in the pathogenesis of fatty liver disease in rats. The recipes of CM, especially invigorating Spleen recipe and soothing Liver recipe, might protect liver against injury by reducing the total JNK protein content and inhibiting the activation of JNK protein in Kupffer cells of fatty liver model rats, which showed beneficial effects on fatty liver disease.

Effects of Soothing Liver and Invigorating Spleen Recipe on Lipid Metabolism Disorders in Kupffer Cells of NAFLD Rats by LXRα/SREBP-1c Signal Pathway

Objective To investigate the mechanism of lipid metabolism disorders in Kupffer cells （KCs） of non-alcoholic fatty liver disease （NAFLD） rats mediated by LXRα-SREBP-lc pathway and the interference of soothing liver and invigorating spleen recipe （SLISR） on it. Methods SD male rats were randomly divided into five groups： normal, model, soothing liver recipe （SLR）, invigorating spleen recipe （ISR）, and soothing liver and invigorating spleen recipe （SLISR） groups. The rats in treatment groups were administered for 8 weeks. The liver tissue was stained with H＆E and oil red O. The levels of hepatic lipid and blood lipid were measured by biochemical analyzer. KCs were isolated from the livers of rats to evaluate the expression of LXRα, SREBP-1 C, and FAS mRNA by real-time fluorescence quantitative PCR tests; LXRα, SREBP-1C, and FAS proteins were measured by Western blotting. Results The H＆E and oil red O staining results showed that the model rats successfully reproduced typical pathogenetic and histopathological features of NAFLD. The levels of hepatic lipid and blood lipid in the model rats were dramatically increased. Compared with the model group, the values of hepatic lipid and blood lipid in the treatment groups were significantly ameliorated （P〈 0.05, 0.01 ）. The yields of purified KCs from each rat were 2×10^7-3×10^7. The viability of KCs was higher than 95%, with the purity over 90.18%. Compared with the model group, the expression of LXRα, SREBP-1C, and FAS mRNA and proteins was decreased in all treatment groups, especially in the SLR group （P〈 0.05）. Conclusion SLISR may protect liver against injury included by lipid metabolism disorders in KCs through LXRα/ SREBP-1 c signaling pathway, which may be an important mechanism for the prevention and treatment of NAFLD.

The polarizable and reprogrammable identity of Kupffer cells in Nonalcoholic Steatohepatitis

Kupffer cells(KCs)are the resident macrophages of the liver with similar origins to myeloid-derived macrophages.Once differentiated,KCs exhibit distinct cellular machinery capable of longevity and self-renewal,making them a crucial player in promoting effective intrahepatic communication.However,this gets compromised in disease states like Nonalcoholic Steatohepatitis(NASH),where the loss of embryo-derived KCs(EmKCs)is observed.Despite this,other KC-like and KC-derived populations start to form and contribute to a variety of roles in NASH pathogenesis,often adopting a NASH-associated molecular signature.Here we offer a brief overview of recent reports describing KC polarization and reprogramming in the liver.We describe the complexities of KC cellular identity,their proposed ability to reprogram to fibroblast-like and endothelial-like cells,and the potential implications in NASH.

CD205-TLR9-IL-12 axis contributes to CpG-induced oversensitive liver injury in HBsAg transgenic mice by promoting the interaction of NKT cells with Kupffer cells

Gut-derived bacterial products contribute to liver inflammation and injury during chronic hepatitis B virus infection;however,the underlying mechanisms remain obscure.In this study,hepatitis B surface antigen transgenic(HBs-Tg)mice and their wild-type(WT)control C57BL/6 mice were injected with CpG-oligodeoxynucleotides(ODNs)to mimic the translocation of gut microbial products into the systemic circulation.We found that,compared with the WT mice,the HBs-Tg mice were oversensitive to CpG-ODN-induced liver injury,which was dependent on natural killer T(NKT)cells.CpG-ODN injection enhanced the expression of Fas ligand(FasL)on NKT cells.In addition,hepatocytes from the HBs-Tg mice expressed higher levels of Fas than did those from the WT mice,which was further augmented by CpG-ODN.Interaction of Fas and FasL was involved in the cytotoxicity of NKT cells against hepatocytes in the HBs-Tg mice.Moreover,Kupffer cells in the HBs-Tg mice expressed higher levels of CD205 and produced greater amounts of interleukin(IL)-12 than did those in the WT mice.Finally,the depletion of Kupffer cells,neutralization of IL-12 or specific silencing of CD205 on Kupffer cells significantly inhibited CpG-ODN-induced liver injury and NKT activation in the HBs-Tg mice.Our data suggest that CD205-expressing Kupffer cells respond to CpG-ODNs and subsequently release IL-12 to promote NKT cell activation.Activated NKT cells induce liver damage through the Fas signaling pathway in HBs-Tg mice.

Synthesis of Toll-like receptor 4 in Kupffer cells and its role in a lcohol-induced liver disease

s To observe the synthesis of Toll like receptor (TLR) 4 protein and its mRNA exp ression in Kupffer cells (KCs) and evaluate the role of TLR 4 in liver injury to rats through alcohol induced liver disease Methods Twenty eight Wistar rats were divided into two groups: ethanol fed (group E) a nd control (group C) Group E rats were given ethanol at a dose of 5-12 g·kg 1 ·d 1 , while group C received dextrose Animals from bot h groups were killed at 4 and 8 weeks The KCs were isolated and synthesis of T LR 4 protein was determined by laser scanning confocal microscopy TLR 4 mRNA e xpression in KCs was determined by reverse transcription polymerase chain reacti on (RT PCR) analysis The levels of endotoxin, tumor necrosis factor α (TN F α) and interleukin 6 (IL 6) in plasma were determined Changes in liver pathology were observed Results Laser scanning confocal microscopy showed that the intensity of fluorescence of TLR 4 protein in group E was stronger than group C Ethanol administration led to a significant increase in TLR 4 mRNA expression in group E compared with grou p C ( P <0 05) The concentrations of plasma endotoxin, TNF α and IL 6 were higher in group E than in group C ( P <0 05) Liver sections from rat s in group E demonstrated marked pathological changes Conclusion Ethanol administration can lead to the synthesis of TLR 4 protein and its gene e xpression in KCs, indicating that TLR 4 may play a major role in the development of alcohol induced liver injury

Altered Endothelin-1 Signaling in Production of Thromboxane A_(2) in Kupffer Cells from Bile Duct Ligated Rats

Kupffer cells(KCs),the liver resident macrophages accounting for 80-90%of the total population of fixed tissue macrophages in the body,not only play a key role in host defense via removing particulate materials from the portal circulation,but may also contribute to the pathogenesis of various liver diseases.We have previously demonstrated that KCs play an important role in controlling portal hypertension and hepatocellular injury via releasing thromboxane A_(2)(TXA_(2))in early fibrosis induced by one-week bile duct ligation(BDL).Production of TXA_(2) is controlled by cytosolic phospholipase A_(2)(cPLA_(2))that is activated by the interaction of entothelin-1(ET-1)with its G-protein coupled ET receptor B(ETBR).However,the signaling pathways that contribute to the ET-1-induced activation of cPLA_(2) and production of TXA_(2) in KCs in the normal healthy or injured livers are not yet clear,which are investigated in the present study using isolated KCs from one-week BDL or sham rats.The pharmacological inhibition of cPLA_(2) or chelation of intracellular calcium abrogated the ET-1 induction of TXA_(2) from KCs.Compared to those from sham rats,KCs from BDL animals displayed a significantly enhanced responsiveness of p38 MAPK to ET-1,increased ETBR and Gai subunit but decreased Gaq and Ga11 expression.Inhibition of ERK1/2 or Gq signaling abrogated significantly the ET-1 induction of TXA_(2) in sham KCs but only slightly in BDL KCs.In contrast,inhibition of p38 MAPK and Gi signaling markedly attenuated the ET-1 induction of TXA_(2) in BDL KCs but had no effect in sham KCs.Lastly,inhibition of PLC or PKC abrogated ET-1 induction of TXA_(2) in KCs from both sham and BDL groups.The hepatic stress(such as BDL)induces significant modifications in the receptor and intermediates of ET-1 signaling in KC and subsequently alters ET-1 signaling mechanisms,particularly a shift from Gq induced signaling to Gi induced signaling,in the activation of cPLA_(2) and production of TXA_(2) in response to ET-1.

Effects of Kupffer cells stimulated by triglyceride and very low-density lipoprotein on proliferation of rat hepatic stellate cells

Objective To study the effects of triglyceride, very low density lipoprotein (VLDL), and Kupffer cell conditioned medium (KCCM) derived from triglyceride and VLDL treatment on proliferation of rat hepatic stellate cells (HSC). Methods HSC and Kupffer cells were isolated and cultured from liver of Wistar rats by in situ perfusion with proteinase and collagenase, and density gradient centrifugation with Nycodenz; HSC and Kupffer cells were identified by immunohistochemistry, endocytosis, and ultrastructure, etc. Kupffer cells were incubated with triglyceride (25 μg/ml) and VLDL (25 μg/ml) for 24 hours, KCCM were prepared, and MTT colorimetric assay was detected for HSC proliferation. Results HSC proliferation was 0.1894±0.0316 (12.5 μg/ml), 0.1637±0.0243 (25 μg/ml), 0.1450± 0.0264 (50 μg/ml), 0.1212±0.0275 (100 μg/ml), 0.1226 ±0.0138 (200 μg/ml) and 0.0990±0.0163 (400 μg/ml) in the presence of triglyceride and was 0.1583±0.0314 (6.25 μg/ml), 0.1642±0.0269 (12.5 μg/ml), 0.1834±0.0498 (25 μg/ml), 0.1964± 0.0287 (50 μg/ml) and 0.2202±0.0284 (100 μg/ml) in presence of VLDL, respectively. Compared with the control, HSC proliferation at 400 μg/ml of triglyceride was lower (P<0.01), but at 12.5 μg/ml of triglyceride and 25, 50, 100 μg/ml of VLDL higher (P<0.05 or 0.01); HSC proliferation was 0.1569± 0.0144, 0.1924±0.0113 and 0.1871±0.0116 in the presence of KCCM, KCCM+triglyceride and KCCM+VLDL, respectively. Compared with the control and KCCM, KCCM+triglyceride and KCCM+VLDL might promote HSC proliferation (P<0.01); there was no statistical significance between KCCM+ triglyceride and KCCM+VLDL (P>0.05); KCCM was greater in HSC proliferation than the control, but there was no significant change (P>0.05). Conclusions Triglyceride, VLDL, and KCCM stimulated by triglyceride and VLDL might promote HSC proliferation and be associated with fatty liver and hepatic fibrogenesis.

Effects of Kupffer cell inactivation on graft survival and liver regeneration after partial liver transplantation in rats

BACKGROUND： Gadolinium chloride（Gd Cl3） selectively inactivates Kupffer cells and protects against ischemia/reperfusion and endotoxin injury. However, the effect of Kupffer cell inactivation on liver regeneration after partial liver transplantation（PLTx） is not clear. This study was to investigate the role of Gd Cl3 pretreatment in graft function after PLTx, and to explore the potential mechanism involved in this process.METHODS： PLTx（30% partial liver transplantation） was performed using Kamada’s cuff technique, without hepatic artery reconstruction. Rats were randomly divided into the control low-dose（5 mg/kg） and high-dose（10 mg/kg） Gd Cl3 groups. Liver injury was determined by the plasma levels of alanine aminotransferase and aspartate aminotransferase, liver regeneration by PCNA staining and Brd U uptake, apoptosis by TUNEL assay. IL-6 and p-STAT3 levels were measured by ELISA and Western blotting.RESULTS： Gd Cl3 depleted Kupffer cells and decreased animal survival rates, but did not significantly affect alanine aminotransferase and aspartate aminotransferase（P〉0.05）. Gd Cl3 pretreatment induced apoptosis and inhibited IL-6 overexpression and STAT3 phosphorylation after PLTx in graft tissues.CONCLUSION： Kupffer cells may contribute to the liver regeneration after PLTx through inhibition of apoptosis and activation of the IL-6/p-STAT3 signal pathway.

Roles of liver innate immune cells in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease in the United States and other developed countries and is expected to increase in the next few years. Emerging data suggest that some patients with NAFLD may progress to nonalcoholic steatohepatitis (NASH), cirrhosis and even hepatocellular carcinoma. NAFLD can also promote the development and progression of disease in other organ systems, such as the cardiovascular and endocrine (i.e. diabetes) systems. Thus, understanding the pathogenesis of NAFLD is of great clinical importance and is critical for the prevention and treatment of the disease. Although the "two-hit hypothesis" is generally accepted, the exact pathogenesis of NAFLD has not been clearly established. The liver is an important innate immune organ with large numbers of innate immune cells, including Kupffer cells (KCs), natural killer T (NKT) cells and natural killer (NK) cells. Recent data show that an imbalance in liver cytokines may be implicated in the development of fatty liver disease. For example, Th1 cytokine excess may be a common pathogenic mechanism for hepatic insulin resistance and NASH. Innate immune cells in the liver play important roles in the excessive production of hepatic Th1 cytokines in NAFLD. In addition, liver innate immune cells participate in the pathogenesis of NAFLD in other ways. For example, activated KCs can generate reactive oxygen species, which induce liver injury. This review will focus primarily on the possible effect and mechanism of KCs, NKT cells and NK cells in the development of NAFLD.

Effect of aging on cytoskeleton system of Kupffer cell and its phagocytic capacity

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DYNAMIC CHANGES OF ITO CELLS IN EXPERIMENTAL LIVER CIRRHOSIS OF RAT

That Ho cells in rat liver express desmin was confirmed by immunohistochemical technique. Consequently, changes of desmin-positive cells, lysozyme-positive cells and fibronectin were further studied in experimental cirrhosis of rat. It was found that desmln- positive cells, with the transitional feature between Ito cells and myofibroblasts or fibrobiasts under electron microscope, increased in number and expression of desmin in the necrotic areas as well as in the cellular fibrous septa, but decreased in number in the fibrous septa except those areas closed to the edges of the septa. These results suggested that Ito cells, myofibroblasts and fibroblasts might belong to the same cellular system and play an important role in the pathogenesis of cirrhosis. Meanwhile, it was also noted that changes of both fibronectin and lysozymepositive cells were correlated with those of desmin-positive cells. These provide evidence in vivo that flbronectin and Kupffer cells might exert certain effects on the migration and proliferation of Ito cells in liver cirrhosis.