The role of CD14 and Toll-like receptor 4 of Kupffer cells in hepatic ischemia-reperfusion injury in rats. Transplant Proc. 2012;44:937-941. [PMID: 22564590 DOI: 10.1016/j.transproceed.2011.11.001]

Targeting NF-κB in Hepatic Ischemia-Reperfusion Alleviation: from Signaling Networks to Therapeutic Targeting

Hepatic ischemia-reperfusion injury (HIRI) is a major complication of liver trauma, resection, and transplantation that can lead to liver dysfunction and failure. Scholars have proposed a variety of liver protection methods aimed at reducing ischemia-reperfusion damage, but there is still a lack of effective treatment methods, which urgently needs to find new effective treatment methods for patients. Many studies have reported that signaling pathway plays a key role in HIRI pathological process and liver function recovery mechanism, among which nuclear transfer factor-κB (NF-κB) signaling pathway is one of the signal transduction closely related to disease. NF-κB pathway is closely related to HIRI pathologic process, and inhibition of this pathway can delay oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction. In addition, NF-κB can also interact with PI3K/Akt, MAPK, and Nrf2 signaling pathways to participate in HIRI regulation. Based on the role of NF-κB pathway in HIRI, it may be a potential target pathway for HIRI. This review emphasizes the role of inhibiting the NF-κB signaling pathway in oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction in HIRI, as well as the effects of related drugs or inhibitors targeting NF-κB on HIRI. The objective of this review is to elucidate the role and mechanism of NF-κB pathway in HIRI, emphasize the important role of NF-κB pathway in the prevention and treatment of HIRI, and provide a theoretical basis for the target NF-κB pathway as a therapy for HIRI.

Sulforaphane Is Protective against Warm Ischemia/Reperfusion Injury and Partial Hepatectomy in Rats

Sulforaphane (SFN) has various beneficial effects on organ metabolism. However, whether SFN affects inflammatory mediators induced by warm hepatic ischemia/reperfusion injury (HIRI) is unclear. To investigate the hepatoprotective effects of SFN using an in vivo model of HIRI and partial hepatectomy (HIRI + PH), rats were subjected to 15 min of hepatic ischemia with blood inflow occlusion, followed by 70% hepatectomy and release of the inflow occlusion. SFN (5 mg/kg) or saline was randomly injected intraperitoneally 1 and 24 h before ischemia. Alternatively, ischemia was prolonged for 30 min to evaluate the effect on mortality. The influence of SFN on the associated signaling pathways was analyzed using the interleukin 1β (IL-1β)-treated primary cultured rat hepatocytes. In the HIRI + PH-treated rats, SFN reduced serum liver enzyme activities and the frequency of pathological liver injury, such as apoptosis and neutrophil infiltration. SFN suppressed tumor necrosis factor-alpha (TNF-α) mRNA expression and inhibited nuclear factor-kappa B (NF-κB) activation by HIRI + PH. Mortality was significantly reduced by SFN. In IL-1β-treated hepatocytes, SFN suppressed the expression of inflammatory cytokines and NF-κB activation. Taken together, SFN may have hepatoprotective effects in HIRI + PH in part by inhibiting the induction of inflammatory mediators, such as TNF-α, via the suppression of NF-κB in hepatocytes.

Targeting Oxidative Stress with Polyphenols to Fight Liver Diseases

Reactive oxygen species (ROS) are important second messengers in many metabolic processes and signaling pathways. Disruption of the balance between ROS generation and antioxidant defenses results in the overproduction of ROS and subsequent oxidative damage to biomolecules and cellular components that disturb cellular function. Oxidative stress contributes to the initiation and progression of many liver pathologies such as ischemia-reperfusion injury (LIRI), non-alcoholic fatty liver disease (NAFLD), and hepatocellular carcinoma (HCC). Therefore, controlling ROS production is an attractive therapeutic strategy in relation to their treatment. In recent years, increasing evidence has supported the therapeutic effects of polyphenols on liver injury via the regulation of ROS levels. In the current review, we summarize the effects of polyphenols, such as quercetin, resveratrol, and curcumin, on oxidative damage during conditions that induce liver injury, such as LIRI, NAFLD, and HCC.

Targeting the Hepatic Microenvironment to Improve Ischemia/Reperfusion Injury: New Insights into the Immune and Metabolic Compartments

Hepatic ischemia/reperfusion injury (IRI) is mainly characterized by high activation of immune inflammatory responses and metabolic responses. Understanding the molecular and metabolic mechanisms underlying development of hepatic IRI is critical for developing effective therapies for hepatic IRI. Recent advances in research have improved our understanding of the pathogenesis of IRI. During IRI, hepatocyte injury and inflammatory responses are mediated by crosstalk between the immune cells and metabolic components. This crosstalk can be targeted to treat or reverse hepatic IRI. Thus, a deep understanding of hepatic microenvironment, especially the immune and metabolic responses, can reveal new therapeutic opportunities for hepatic IRI. In this review, we describe important cells in the liver microenvironment (especially non-parenchymal cells) that regulate immune inflammatory responses. The role of metabolic components in the diagnosis and prevention of hepatic IRI are discussed. Furthermore, recent updated therapeutic strategies based on the hepatic microenvironment, including immune cells and metabolic components, are highlighted.

The impact on the bioenergetic status and oxidative-mediated tissue injury of a combined protocol of hypothermic and normothermic machine perfusion using an acellular haemoglobin-based oxygen carrier: The cold-to-warm machine perfusion of the liver

Introduction

The combination of hypothermic and normothermic machine perfusion (HMP+NMP) of the liver provides individual benefits of both techniques, improving the rescue of marginal organs. The aim of this study was to investigate the effect on the bioenergetic status and the oxidative-mediated tissue injury of an uninterrupted combined protocol of HMP+NMP using a single haemoglobin-based oxygen carrier (HBOC)-based perfusate.

Methods

Ten discarded human donor livers had either 2 hours of dual hypothermic oxygenated perfusion (D-HOPE) with sequential controlled rewarming (COR) and then NMP using the HBOC-based perfusate uninterruptedly (cold-to-warm group); or 2 hours of hypothermic oxygenated perfusion (HOPE) with an oxygen carrier-free perfusate, followed by perfusate exchange and then NMP with an HBOC-based perfusate. Markers of liver function, tissue adenosine triphosphate (ATP) levels and tissue injury were systematically assessed.

Results

The hypothermic phase downregulated mitochondrial respiration and increased ATP levels in both groups. The cold-to-warm group presented higher arterial vascular resistance during rewarming/NMP (p = 0.03) with a trend of lower arterial flow (p = 0.09). At the end of NMP tissue expression of markers of reactive oxygen species production, oxidative injury and inflammation were comparable between the groups.

Conclusion

The uninterrupted combined protocol of HMP+NMP using an HBOC-based perfusate—cold-to-warm MP—mitigated the oxidative-mediated tissue injury and enhanced hepatic energy stores, similarly to an interrupted combined protocol; however, it simplified the logistics of this combination and may favour its clinical applicability.

Telluric acid ameliorates hepatic ischemia reperfusion-induced injury in rats: Involvement of TLR4, Nrf2, and PI3K/Akt signaling pathways

In past tellurium-based compounds had limited use, however, their therapeutic potential have been target of interest recently due to antioxidant and anti-inflammatory capabilities in experimental endotoxemia. Nevertheless, their potential hepatoprotective effect against ischemia reperfusion (IR) injury is still obscure. This study examined the possible hepatoprotective effect of telluric acid (TELL), one of tellurium-based compound, against the deteriorating effect hepatic IR injury in rats through directing toll like receptor-4 (TLR4) cascade, phosphoinositide 3-kinase(PI3K)/Akt axis, and nuclear erythroid-related factor-2 (Nrf-2) pathway as possible mechanisms contributed to TELL's effect. Indeed, male Wistar rats were randomized into 3 groups: sham-operated, control IR and TELL (50 µg/kg). TELL was administrated once daily for seven consecutive days prior to the IR induction. Pretreatment with TELL attenuated hepatic IR injury as manifested by hampered plasma aminotransaminases and lactate dehydrogenase activities. Also, TELL opposed IR induced elevation in tissue expression/activity of high-mobility group box protein-1 (HMGB1), TLR4, myeloid differentiation primary-response protein 88 (MyD88), phospho-nuclear factor-kappa B p65 (p-NF-κB p65), phospho-mitogen activated protein kinasep38 (p-MAPKp38) and tumor necrosis factor-alpha (TNF-α). Moreover, TELL reduced the elevated thiobarbituric acid reactive substances along with increased both Nrf-2 and endothelial nitric oxide synthase (eNOS) protein expression, beside replenishment of hepatic reduced glutathione. In addition, TELL induced obvious upregulation of p-PI3K and p-Akt protein expressions together with restoration of histopathological changes in IR injury. In conclusion, TELL purveyed conceivable novel hepatoprotective mechanisms and attenuated events associated with acute hepatic injury via inhibition of TLR4 downstream axis and activation of Nrf-2 and PI3K/Akt signaling cascades. Thus, TELL may provide a novel therapeutic potential for complications of hepatic IR injury.

MicroRNA-125b protects liver from ischemia/reperfusion injury via inhibiting TRAF6 and NF-κB pathway

MicroRNA-125b (miR-125b), which was previously proved to be a potential immunomodulator in various disease, attenuated mouse hepatic ischemia/reperfusion (I/R) injury in this study. miR-125b was decreased in RAW 264.7 cells exposed to hypoxia/reoxygenation (H/R). The expression of IL-1β, IL-6 and TNF-α in both serum and supernate were reduced in miR-125b over-expression groups. The hepatic histopathological changes were reduced in miR-125b agomir groups. In the miR-125b antagomir groups, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly elevated compared with negative control (NC) groups. The protein expression of TNF receptor-associated factor 6 (TRAF6), IL-1β and the phosphorylation of p65 (p-p65) were suppressed by the up-regulation of miR-125b. Furthermore, the nuclear translocation of p-p65, measured by immunofluorescence, was enhanced by the miR-125b inhibitors. In conclusion, our study indicates that miR-125b protects liver from hepatic I/R injury via inhibiting TRAF6 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signal pathway.

MicroRNA-155 Deficiency in Kupffer Cells Ameliorates Liver Ischemia-Reperfusion Injury in Mice

BACKGROUND

MicroRNA-155 (miR-155) is known to be involved in autoimmune diseases, inflammation, and transplantation. However, its role in a warm hepatic ischemia-reperfusion (IR) model has not been fully elucidated.

METHODS

Partial hepatic IR was performed in wild-type and miR-155-deficient mice treated with or without GdCl3, and then the serum transaminase concentration and histology were analyzed. Kupffer cells (KCs) were isolated from the liver after IR, and immunohistochemistry was used to evaluate activation and polarization. In addition, the mRNA concentrations of various inflammatory cytokines were measured. Macrophages were obtained from the abdominal cavity and challenged with or without lipopolysaccharide to determine the influence of miR-155 deficiency on macrophage polarization in vitro. Furthermore, we used in vitro coculture assays to determine the effect of miR-155 deficiency on hepatocyte apoptosis induced directly by KCs.

RESULTS

miR-155 deficiency ameliorated liver IR injury, and inhibition of KCs by GdCl3 abolished this protective effect. miR-155 deficiency decreased CD80, CD86, and major histocompatibility complex class II expression in KCs after IR and tipped the M1/M2 balance toward an anti-inflammatory profile, where proinflammatory cytokine secretion was suppressed and IL-10 was enhanced. In addition, hepatocyte apoptosis was reduced in coculture with miR-155-deficient KCs in vitro.

CONCLUSIONS

miR-155 deficiency plays an effective role in attenuating liver IR injury likely by regulating the activation and inflammatory response, as well as modifying the polarization of KCs.

IRAK-4-shRNA Prevents Ischemia/Reperfusion Injury Via Different Perfusion Periods Through the Portal Vein After Liver Transplantation in Rat

BACKGROUND

This study analyzed the effects of short hairpin RNA targeting interleukin-1 receptor-associated kinase-4 (IRAK-4-shRNA) via portal vein perfusion during different periods on ischemia/reperfusion injury after liver transplantation.

METHODS

Rats were randomly divided into 3 groups: the cold ischemia transfection group (CIT group, n = 18), in which graft livers were perfused with the plasmid of pSIIRAK-4 expressing IRAK-4-shRNA for 4 minutes (0.5 mL/min) via the portal vein during the cold ischemia period; the in vivo transfection group (IVT group, n = 18), in which equivalent volumes (2 mL) of IRAK-4-ShRNA plasmid (pSIIRAK-4) were injected during the operation; and the control group (n = 18), in which the rats received equivalent volumes of blank plasmid. At 0, 60, and 180 minutes after portal vein reperfusion, blood and liver tissues were collected for examination. IRAK-4 expression, nuclear factor kB (NF-kB) activity, tumor necrosis factor α, interleukin (IL)-1β, and IL-6 serum levels, as well as histologic changes, were detected.

RESULTS

At 0 minutes after reperfusion, IRAK-4 expression, NF-κB activity, and serum levels of tumor necrosis factor α, IL-1β, and IL-6 showed no significant differences among the 3 groups (P > .05). At 60 and 180 minutes after reperfusion, all indices of the IVT and control groups were significantly higher than those of the CIT group (P < .01). Meanwhile, all indices of the CIT group showed no significant differences at various time points (P > .05). Liver function and histologic changes exhibited less liver injury in the CIT group than in the other groups.

CONCLUSIONS

IRAK-4 activity was suppressed by IRAK-4-shRNA through portal vein perfusion during the cold ischemia period, and IRAK-4-shRNA effectively prevented ischemia/reperfusion injury after liver transplantation.

Resveratrol preconditioning protects hepatocytes against hepatic ischemia reperfusion injury via Toll-like receptor 4/nuclear factor-κB signaling pathway in vitro and in vivo

The purpose of this study was to investigate the protective effect of resveratrol against hepatic ischemia reperfusion injury (HIRI) and explore the potential underlying mechanism. Resveratrol-pretreated BRL-3A (rat liver) cells and rats underwent hypoxia/reoxygenation and hepatic ischemia/reperfusion, respectively. BRL-3A cell damage was evaluated, and the mRNA and protein expression of related signal molecules was assessed in cell model. The protein expression of related signal molecules was also assessed in rat model. Inflammatory cytokines levels were determined in the cell supernatant and rat serum while rat liver function and hepatocyte apoptosis were assessed. The results revealed that resveratrol significantly enhanced cell viability, inhibited cell apoptosis, and decreased levels of lactate dehydrogenase (LDH) and production of tumor necrosis factor-α (TNF-α) and interleukin-(IL)-1β in the cell supernatant. In addition, resveratrol ameliorated elevated Toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB, and the depressed inhibitor of NF-κB (IκB)-α caused by hypoxia/reoxygenation stimulation in BRL-3A cells. Moreover, resveratrol inhibited the translocation of NF-κB p65 after the stimulation of hypoxia/reoxygenation in BRL-3A cells. In vivo assays revealed that resveratrol reduced levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and liver pathological changes, while it alleviated hepatocyte apoptosis, negatively mediated the production of TNF-α and IL-1β in serum, and reversed TLR4/NF-κB signaling pathway caused by hepatic ischemia/reperfusion stimulation in liver tissues. The results indicate that resveratrol protected hepatocytes against HIRI, which may be mediated in part via the TLR4/NF-κB signaling pathway.

Role of Kupffer cells in hepatitis B/C viral hepatitis

Kupffer cells (KCs) are the largest group of tissue macrophages. KCs in the hepatic sinusoid contact with pathogens from circulation earliest. The quantity of KCs increases significantly in patients with viral hepatitis, suggesting that KCs play an important role in viral hepatitis related immunity. KCs can not only engulf virus particles, but also present antigens, secrete cytokines, and participate in a variety of inflammatory responses, immune tolerance and liver injury. In hepatitis B virus (HBV)/hepatitis C virus (HCV) infections, the diversity of KCs-related cytokines, the complexity of interactions of receptor signaling pathways as well as the duality of cytotoxic effect, indicate that KCs play a dual role in the immune response; the activation of KCs regulates the balance of inflammatory and anti-inflammatory mechanisms in viral hepatitis.

Toll-like receptor-4 knockout mice are more resistant to optic nerve crush damage than wild-type mice

BACKGROUND

This study aims to investigate the role of the inflammatory response following optic nerve crush (ONC) in knockout mice for the toll-like receptor-4 gene (TLR4-/-) compared to wild-type (WT) mice.

METHODS

ONC was induced in TLR4-/- and C57BL6 WT mice. Histological sections of the retina and optic nerve were analysed on days 1, 3 or 21 after injury. Molecular analysis with real-time quantitative polymerase chain reaction was used to study the expression of CD45, tumour necrosis-alpha (TNF-α) and glial fibrillary acidic protein, as well as retinal ganglion cell (RGC) markers THY-1 and Brn3b.

RESULTS

There was a 25.5% and 38% loss in the RGC layer of the ONC-injured eyes of the TLR4-/- and the WT mice, respectively (with 27% and 9% of the remaining cells positive for Brn3a, respectively). Mean levels of Thy-1 and Brn3b were higher in the TLR4-/- mice. CD45 and Iba1 staining revealed infiltration of inflammatory cells into the injured nerve and retina in both groups. Molecular analysis of the optic nerve on day 1 showed increased TNF-α expression and reduced CD45 and GFAP expression; on day 3, CD45 reverted to baseline but GFAP remained low; on day 21, all 3 markers were at baseline in the TLR4-/- group and decreased in the WT group.

CONCLUSION

Inflammation plays a major role in the response to ONC injury. Reduced levels of inflammation are associated with improved RGC preservation. The increase in TNF-α and reduction in CD45 in both TLR4-/- and WT mice may indicate the presence of an alternative pathway for induction of RGC death.

Kupffer cells and liver transplantation

Nowadays, liver transplantation is globally considered the most effective treatment for end-stage liver diseases. Ischemia-reperfusion (I/R) injury and immune rejection response (IRR) are the two major imperfections which severely affect the recipients' prognosis and survival rate without satisfactory clinical management strategies. Therefore, exploring effective methods to improve I/R injury and IRR have important clinical significance under circumstances of shortage of donor livers. Kupffer cells (KCs) are the largest population of antigen representing cells (APCs) which settle in the liver. As the first defensive line of the live, KCs exhibit various biological effects. However, the exact mechanisms responsible for the role of KCs in I/R injury and IRR remain elusive. We hereby review the current finding about the role of KCs in I/R injury and IRR.

Role of Kupffer cells in bacterial infectious diseases

Kupffer cells (KCs) are also known as liver inherent macrophages, which account for the largest part of human tissue macrophages and participate in the pathogenesis of various liver diseases. In vitro study using primary culture is a valuable tool for the exploration of specific immunological functions of KCs. Obtaining KCs with high purity and activity is the basis for research. A large number of phagocytosable particles and soluble substances can activate KCs by binding to specific receptors on the membrane. The most important molecule that activates KCs is lipopolysaccharide (LPS). A tiny quantity of LPS will drive a Toll-like receptor 4 (TLR4) -dependent proinflammatory response that alerts the host to the presence of infection. Higher quantities of LPS, which reach the cytoplasm, will trigger inflammasome activation, interleukin-1 beta (IL-1β) production and, ultimately, cell death. KCs play an important role in sepsis, endotoxin tolerance and acute pancreatitis. In this review, we describe the role of KCs in these diseases and the underlying molecular mechanisms.

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.

Ghrelin contributes to protection of hepatocellular injury induced by ischaemia/reperfusion

BACKGROUND & AIMS

Ghrelin, a gut hormone with pleiotropic effects, may act as a protective signal in parenchymal cells. We investigated the protective effects of ghrelin on hepatocytes after ischaemia/reperfusion (I/R).

METHODS

Hepatic injury was assessed by measurement of plasma alanine aminotransferase (ALT) and lactate dehydrogenase (LDH), histological analysis, and TUNEL assay. Effects of exogenous ghrelin and ghrelin receptor gene deletion on I/R induced injury of liver were evaluated.

RESULTS

Ischaemia/reperfusion induced a profound injury to hepatocytes. This was accompanied by elevations in plasma ALT and LDH. Pretreatment with ghrelin significantly reduced elevations in plasma ALT and LDH, and attenuated tissue damage induced by hepatic I/R in mice. Hepatic injury induced by I/R was more pronounced in ghrelin receptor gene null mice. Ghrelin administration blocked the up-regulation of AMP-activated protein kinase (AMPK) activity induced by hepatic I/R.

CONCLUSIONS

This study demonstrates that ghrelin contributes to the cytoprotection during hepatic I/R.

CD14 contributes to warm hepatic ischemia-reperfusion injury in mice

INTRODUCTION

Ischemia/reperfusion (I/R) of the liver contributes to the pathobiology of liver injury in transplantation, liver surgery, and hemorrhagic shock. Ischemia/reperfusion induces an inflammatory response that is driven, in part, by Toll-like receptor 4 (TLR) signaling. CD14 is known to participate in the function of TLR4. We hypothesized that CD14 would be involved in the pathobiology of warm hepatic I/R.

METHODS

Using a 70% liver inflow inclusion model, CD14 knockout and wild-type (WT) mice were subjected to 1-h warm ischemia followed by reperfusion. CD14 mRNA, circulating transaminase, interleukin 6, soluble CD14, and high-mobility group box 1 (HMGB1) levels were measured. CD14 neutralizing antibody or isotype control antibody was given before ischemia or reperfusion for CD14 blockade in WT mice. Recombinant HMGB1 was given before reperfusion in some experiments to test if liver injury worsens.

RESULTS

There was an upregulation of CD14 mRNA in reperfused livers together with increased soluble CD14 levels in the circulation. Compared with WT control mice, CD14 knockout mice had much lower alanine aminotransferase and interleukin 6 levels at 6 and 24 h following I/R, and much less liver necrosis by histology. TUNEL (terminal deoxynucleotidyl-transferase dUTP nick end labeling) staining displayed less apoptosis at 24 h in the absence of CD14. CD14 blockage by neutralizing antibody also attenuated liver injury and the inflammatory response in C57BL/6 mice following I/R, but did not provide additional protection to TLR4 mutant C3H/Hej mice. CD14 deficiency did not change circulating HMGB1 levels following I/R (6 h). A dose of recombinant HMGB1, which worsened hepatic injury when given before reperfusion in WT mice, did not increase liver damage in CD14-deficient mice.

CONCLUSIONS

CD14 is actively involved in hepatic I/R injury. Its deficiency or blockade ischemia attenuates liver injury and inflammatory response. CD14 mediates liver damage and inflammatory responses in the setting of warm hepatic I/R in mice.

Soluble CD14 levels reflect liver inflammation in patients with nonalcoholic steatohepatitis

BACKGROUND AIMS

Liver inflammation is a risk factor for the progression of nonalcoholic fatty liver disease (NAFLD). However, the diagnosis of liver inflammation is very difficult and invasive liver biopsy is still the only method to reliably detect liver inflammation. We previously reported that overexpression of CD14 in Kupffer cells may trigger the progression to nonalcoholic steatohepatitis (NASH) via liver inflammation following hyper-reactivity to low-dose lipopolysaccharide. Therefore, the aim of this study was to investigate the relationship between soluble type of CD14 (sCD14) and histological features in patients with NAFLD.

METHODS

Our cohort consisted of 113 patients with liver biopsy-confirmed NAFLD and 21 age-matched healthy controls. Serum sCD14 levels were measured by an enzyme-linked immunosorbent assay.

RESULTS

Serum sCD14 levels were significantly associated with diagnosis of NASH and the area under the receiver operator characteristic curve (AUROC) to distinguish between not NASH and NASH was 0.802. Moreover, serum sCD14 levels were significantly associated with the disease activity based on NAFLD activity score and hepatic CD14 mRNA expression, which is correlated with membrane CD14 (mCD14) expression, in patients with NAFLD. In multiple regression analysis, the serum sCD14 levels were independently associated with liver inflammation. The AUROC to distinguish between mild and severe liver inflammation in patients with NAFLD was 0.752.

CONCLUSIONS

We found that serum sCD14 levels increased significantly with increasing liver inflammation grade in patients with NAFLD, reflecting increased hepatic CD14 expression. Serum sCD14 is a promising tool to predict the worsening of liver inflammation, and may offer a potential biomarker for evaluation of therapeutic effects in NAFLD.