CB2R agonist GW405833 alleviates acute liver failure in mice via inhibiting HIF-1α-mediated reprogramming of glycometabolism and macrophage proliferation.

The inflammatory responses involving infiltration and activation of liver macrophages play a vital role in acute liver failure (ALF). In the liver of ALF mice, cannabinoid receptor 2 (CB2R) is significantly upregulated on macrophages, while CB2R agonist GW405833 (GW) could protect against cell death in acute liver damage. In this study, we investigated the molecular mechanisms underlying the protective effects of GW against ALF in vivo and in vitro from a perspective of macrophage glycometabolism. Mice were pretreated with GW (10 mg/kg, i.p.), then were injected with D-GalN (750 mg/kg, i.p.) and LPS (10 mg/kg, i.p.) to induce ALF. We verified the protective effects of GW pretreatment in ALF mice. Furthermore, GW pretreatment significantly reduced liver macrophage infiltration and M1 polarization, and inhibited the release of inflammatory factors TNF-α and IL-1ß in ALF mice. These protective effects were eliminated by CB2R antagonist SR144528 or in CB2R-/- ALF mice. We used LPS-stimulated RAW264.7 cells as an in vitro M1 macrophage-centered model of inflammatory response, and demonstrated that pretreatment with GW (10 µM) significantly reduced glucose metabolism by inhibiting glycolysis, which inhibited LPS-induced macrophage proliferation and inflammatory cytokines release. We verified these results in a stable CB2R-/- RAW264.7 cell line. Moreover, we found that GW significantly inhibited the expression of hypoxia inducible factor 1α (HIF-1α). Using a stable HIF-1α-/- RAW264.7 cell line, we confirmed that GW reduced the release of inflammatory cytokines from macrophages and inhibited glycolysis by downregulating HIF-1α expression. In conclusion, activation of CB2Rs inhibits the proliferation of hepatic macrophages and release of inflammatory factors in ALF mice through downregulating HIF-1α to inhibit glycolysis.

Comparison of methods of isolating extracellular vesicle microRNA from HepG2 cells for High-throughput sequencing.

Background: Extracellular vesicles (EVs) were reported to participate in various cellular processes based on the biomolecules, particularly microRNAs. Numerous commercial EVs isolation reagents are available. However, whether these reagents are suitable for separating EVs from the culture medium supernatant supernatant of model cell lines, such as HepG2, and whether the isolated products are suitable for High-throughput sequencing remains unclear. Methods: We examined three commonly used EVs isolation kits: the ExoQuick-TC exosome precipitation solution (EQ), Total Exosome Isolation from cell culture medium (EI), and exoEasy Maxi Kit (EM), to isolate EVs from HepG2 cell culture medium supernatants. EVs were identified based on marker proteins, particle size measurements, and electron microscopy analysis. The total amounts of microRNA and microRNA High-throughput sequencing data quality from EVs isolated by each kit were compared. Results: The total amount of EVs' microRNA isolated from the EI and EM groups were higher than that obtained from the EQ group (EQ/EI: p = 0.036, EI/EM: p = 0.024). High-throughput sequencing data quality evaluation showed that the EI group possessed higher quality than those in the EM group. Conclusion: For the cell culture medium from HepG2, EVs' microRNA isolated by EI reagents might be more suitable for High-throughput sequencing applications.

Caffeine alleviates acute liver injury by inducing the expression of NEDD4L and deceasing GRP78 level via ubiquitination.

BACKGROUND: Acute liver injury is liver cell injury that occurs rapidly in a short period of time. Caffeine has been shown to maintain hepatoprotective effect with an unclear mechanism. Endoplasmic reticulum stress (ERS) has significant effects in acute liver injury. Induction of GRP78 is a hallmark of ERS. Whether or not caffeine's function is related to GRP78 remains to be explored. METHODS: Acute liver injury model was established by LPS-treated L02 cells and in vivo administration of LPS/D-Gal in mice. Caffeine was pre-treated in L02 cells or mice. Gene levels was determined by real-time PCR and western blot. Cell viability was tested by CCK-8 assay and cell apoptosis was tested by flow cytometry. The interaction of GRP78 and NEDD4L was determined by Pull-down and co-immunoprecipitation (Co-IP) assay. The ubiquitination by NEDD4L on GRP78 was validated by in vitro ubiquitination assay. RESULTS: Caffeine protected liver cells against acute injury induced cell apoptosis and ERS both in vitro and in vivo. Suppression of GRP78 could block the LPS-induced cell apoptosis and ERS. NEDD4L was found to interact with GRP78 and ubiquitinate its lysine of 324 site directly. Caffeine treatment induced the expression of NEDD4L, resulting in the ubiquitination and inhibition of GRP78. CONCLUSION: Caffeine mitigated the acute liver injury by stimulating NEDD4L expression, which inhibited GRP78 expression via ubiquitination at its K324 site. Low dose of caffeine could be a promising therapeutic treatment for acute liver injury.

Efficacy of Peginterferon alfa-2b in Nucleoside Analogue Experienced Patients with Negative HBeAg and Low HBsAg: A Non-Randomized Clinical Trial.

INTRODUCTION: Hepatitis B surface antigen (HBsAg) clearance is the treatment goal for hepatitis B e antigen (HBeAg)-negative patients with chronic hepatitis B (CHB). However, its rate is extremely low with nucleoside (acid) analogues (NAs) monotherapy. Peginterferon could enhance HBsAg clearance. This study aimed to evaluate the efficacy of peginterferon alfa-2b (PegIFNα-2b) in NAs-experienced patients with CHB with negative HBeAg and low HBsAg level. METHODS: HBeAg-negative patients with CHB who had received NAs therapy over 24 weeks with HBsAg < 1500 IU/mL and HBV DNA < 100 IU/mL were enrolled. Patients received either PegIFNα-2b add-on therapy (n = 108) or continuous NAs monotherapy (n = 75). The primary endpoint was HBsAg clearance rate at week 48. RESULTS: At week 48, serum HBV DNA was undetectable among all PegIFNα-2b add-on therapy patients. Almost all patients maintained HBV DNA suppression in the PegIFNα-2b add-on group (100%, 108/108) and NAs monotherapy group (97.33%, 73/75). Only patients with PegIFNα-2b add-on therapy achieved HBsAg clearance (50.93%, 55/108) and HBsAg seroconversion (48.15%, 52/108) at week 48. Patients with baseline HBsAg < 100 IU/mL achieved the highest HBsAg clearance rate and HBsAg seroconversion rate at week 48 (60.87%, 28/46 and 58.70%, 27/46 respectively). HBsAg clearance and HBsAg seroconversion at week 72 had no significant difference with continuing or discontinuing PegIFNα-2b therapy after 48 weeks of treatment. PegIFNα-2b add-on therapy was well tolerated. CONCLUSIONS: PegIFNα-2b add-on therapy increases HBsAg clearance rate and seroconversion rate for HBeAg-negative patients with CHB, particularly for those with lower HBsAg level. It would be unnecessary to prolong PegIFNα-2b duration after 48 weeks of PegIFNα-2b treatment.

Cargo-laden erythrocyte ghosts target liver mediated by macrophages.

Liver-targeted cargo delivery possesses great potential for the treatment of liver disease. It is urgent to find an efficient and biocompatible liver targeted delivery system. This study focused on the liver targeting properties of erythrocyte ghosts and its possible mechanism. Herein, we optimized conditions to fabricate human and mouse erythrocyte ghosts with sufficient room capable of incorporating various model substances. Erythrocyte ghosts are biocompatible cargo carriers because it is derived from autologous red blood cells (RBCs), and the cell size, zeta potential, and biconcave-disk shape of the ghosts were consistent with those of RBCs. An in vivo imaging system and positron emission tomography/computed tomography imaging showed that the ghosts were captured mainly in the liver by intravenous injection of fluorescence or 18F-fluorodeoxyglucose (FDG)-labelled ghosts into mice. In contrast, the main concentration of naked octreotide was trapped in the lungs while naked 18F-FDG was trapped in the heart. However, the concentration of cargo-loaded ghosts decreased significantly in the liver in macrophage-depleted mice. Accordingly, in vitro experiments showed that higher phosphatidylserine exposure was observed in the ghosts (38.9 %) compared to normal erythrocytes (0.69 %), and the phagocytic activity of the macrophage RAW 264.7. on the ghosts was significantly higher than that of normal erythrocytes (p < 0.001). Together they indicate that erythrocyte ghosts show liver targeting properties, and possibly owing to macrophage phagocytosis. This promising and effective therapeutic delivery system may provide therapeutic benefits for liver disease.

Melittin ameliorates inflammation in mouse acute liver failure via inhibition of PKM2-mediated Warburg effect.

Acute liver failure (ALF) is a fatal clinical syndrome with no special drug. Recent evidence shows that modulation of macrophage to inhibit inflammation may be a promising strategy for ALF treatment. In this study we investigated the potential therapeutic effects of melittin, a major peptide component of bee venom both in mice model of ALF and in LPS-stimulated macrophages in vitro, and elucidated the underlying mechanisms. ALF was induced in mice by intraperitoneal injection of D-galactosamine/LPS. Then the mice were treated with melittin (2, 4, and 8 mg/kg, ip). We showed that melittin treatment markedly improved mortality, attenuated severe symptoms and signs, and alleviated hepatic inflammation in D-galactosamine/LPS-induced ALF mice with the optimal dose being 4 mg/kg. In addition, melittin within the effective doses did not cause significant in vivo toxicity. In LPS-stimulated RAW264.7 macrophages, melittin (0.7 µM) exerted anti-oxidation and anti-inflammation effects. We showed that LPS stimulation promoted aerobic glycolysis of macrophages through increasing glycolytic rate, upregulated the levels of Warburg effect-related enzymes and metabolites including lactate, LDHA, LDH, and GLUT-1, and activated Akt/mTOR/PKM2/HIF-1α signaling. Melittin treatment suppressed M2 isoform of pyruvate kinase (PKM2), thus disrupted the Warburg effect to alleviate inflammation. Molecular docking analysis confirmed that melittin targeted PKM2. In LPS-stimulated RAW264.7 macrophages, knockdown of PKM2 caused similar anti-inflammation effects as melittin did. In D-galactosamine/LPS-induced ALF mice, melittin treatment markedly decreased the expression levels of PKM2 and HIF-1α in liver. This work demonstrates that melittin inhibits macrophage activation-mediated inflammation via inhibition of aerobic glycolysis by targeting PKM2, which highlights a novel strategy of using melittin for ALF treatment.

Early Diagnostic Biomarkers of Sepsis for Patients with Acute-on-Chronic Liver Failure: A Multicenter Study.

INTRODUCTION: Sepsis is a complication in acute-on-chronic liver failure (ACLF) patients associated with high rates of mortality and morbidity. Early diagnosis of sepsis in ACLF patients can improve prognosis. This study aimed to explore potential effective biomarkers for the early diagnosis of sepsis in ACLF patients. METHODS: Ninety-four ACLF patients with sepsis were enrolled from 10 hospitals across China from January 2015 to June 2016 as well as 49 ACLF patients without infection from Xiangya Hospital. The first-day admission data and SOFA score and CLIF-SOFA score were collected. The differences of indicators between groups were compared with Kruskal-Wallis test. The receiver-operating characteristic (ROC) curve was analyzed to evaluate the diagnostic efficiency of the selected factors. RESULTS: Soluble triggering receptor expressed on myeloid cell-1 (sTREM-1) and presepsin were significantly higher in ACLF-sepsis patients compared with ACLF patients with no infection (P < 0.001). sTREM-1 and presepsin presented higher diagnostic value in sepsis for ACLF patients compared with other biomarkers [white blood cells (WBC), procalcitonin (PCT) and C-reactive protein (CRP)]. Combining sTREM-1 or presepsin with the CLIF-SOFA score increased the diagnostic efficiency (AUC = 0.876 or AUC = 0.913, respectively). CONCLUSIONS: sTREM-1 and presepsin are potential biomarkers for the early diagnosis of sepsis in ACLF patients. The combination of presepsin and the CLIF-SOFA score is a promising method for diagnosing sepsis in ACLF patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02457637.

Potential predictors for prognosis and postpartum recovery time of acute fatty liver of pregnancy.

BACKGROUND: Acute fatty liver of pregnancy (AFLP) is a potentially lethal condition of pregnant women with a high mortality rate. Potential predictors related to postpartum recovery time and prognostic factors of AFLP are still unclear. This study aimed to evaluate potential predictors for prognosis and postpartum recovery time of AFLP. METHODS: We retrospectively analyzed the clinical data of 76 AFLP patients in our hospital from 2002 to 2017 and investigated potential predictors using univariate analysis and multivariate logistic regression analysis. RESULTS: Hepatic encephalopathy (HE) was found to be associated with prognosis in AFLP patients (P = 0.005, OR = 26.844). The postpartum recovery time analysis showed that AFLP patients with a age < 25 had the shortest recovery time, but no significant difference (P = 0.134, OR = 5.952). The postpartum recovery time of patients with liver failure (LF) was significantly prolonged compared to those without LF (P = 0.036, OR = 10.052). Cryoprecipitate, and plasma infusion showed no significant effect on prognosis or recovery time. Artificial liver support therapy (ALST) had no effect on prognosis, but it might affect postpartum recovery time with no statistical significance (P = 0.128, OR = 5.470). CONCLUSION: HE is a potential predictor for prognosis of AFLP. LF is a potential predictor for postpartum recovery time.

LncRNA TP73-AS1/miR-539/MMP-8 axis modulates M2 macrophage polarization in hepatocellular carcinoma via TGF-ß1 signaling.

PURPOSE: Our study aimed to study the role of lncRNA TP73-AS1/miR-539/MMP-8 axis in modulating M2 macrophage polarization in hepatocellular carcinoma (HCC). METHODS: The gene expression levels of TP73-AS1, miR-539 and MMP-8 were modified by transfection with the overexpression or knockdown vectors. The patient survival rate was analyzed using Kaplan-Meier method. The levels of TP73-AS1, miR-539, MMP-8 and M1/2 macrophage polarization markers were analyzed by qRT-PCR, western blot, and flow cytometry. The release of TGF-ß1 in the supernatant was determined by ELISA assay. The interaction between TP73-AS1, miR-539 and MMP-8 was analyzed by bioinformatics analysis and dual-luciferase reporter assays. Mouse xenograft model was further established to examine the therapeutic effects of the TP73-AS1 knockdown and miR-539 overexpression in vivo. RESULTS: We found TP73-AS1 and MMP-8 upregulation, and miR-539 downregulation in HCC tissues and cell lines. Lower TP73-AS1 and MMP-8 expressions and higher miR-539 expression were associated with higher survival rate of patients. M2-macrophage markers CD206, Arg-1 and CD163 were significantly upregulated in the tumor tissues. TP73-AS1 negatively and directly regulated miR-539 and knockdown of TP73-AS1 inhibited MMP-8 expression and M2 macrophage polarization. Also, overexpression of miR-539 suppressed M2 macrophage polarization by negatively regulating MMP-8. Furthermore, knockdown of MMP-8 also restrained M2 macrophage polarization via inhibiting TGF-ß1 signaling. We also found knockdown of TP73-AS1 or overexpression of miR-539 inhibited HCC tumor growth and M2 macrophage infiltration in vivo. CONCLUSION: Our study demonstrated lncRNA TP73-AS1 negatively regulated miR-539 to promote MMP-8 expression, which activated TGF-ß1 signaling to induce M2 macrophage polarization in HCC.

HBx regulates transcription factor PAX8 stabilization to promote the progression of hepatocellular carcinoma.

Transcription factor PAX8 expression is upregulated in several types of cancers. However, little is known about the function of PAX8 in the progression of hepatoma and its regulatory mechanisms. Here, we show that PAX8 silencing inhibits the proliferation and clonogenicity of hepatoma cells and its growth in vivo. The HBV X protein (HBx) does not directly interacts, but stabilizes PAX8 by inhibiting proteasome-dependent ubiquitination and degradation. Furthermore, the E3 ubiquitin ligase complex component Skp2 through its LRR domain directly interacts with the Prd domain of PAX8 and targets PAX8 by recognizing its lysine 275 for ubiquitination and degradation in hepatoma cells. In addition, HBx directly interacts and is colocalized with Skp2 to inhibit its recognition and subsequent ubiquitination and degradation of PAX8 in hepatoma cells. Moreover, HBx upregulates the expression and phosphorylation of Aurora A, a serine-threonine kinase, which interacts with and phosphorylates PAX8 at S209 and T277, compromising the Skp2-recognized PAX8 ubiquitination and destabilization. Thus, HBx stabilizes PAX8 protein by inhibiting the Skp2 targeted PAX8 ubiquitination and enhancing the Aurora A-mediated its phosphorylation, contributing to the progression of hepatoma. Our findings suggest that PAX8 may a new target for design of therapies and uncover new insights into the pathogenesis of hepatoma.

Protective effects of specific cannabinoid receptor 2 agonist GW405833 on concanavalin A-induced acute liver injury in mice.

Cannabinoid receptor 2 (CB2R) is highly expressed in immune cells and plays an important role in regulating immune responses. In the current study, we investigated the effects of GW405833 (GW), a specific CB2R agonist, on acute liver injury induced by concanavalin A (Con A). In animal experiments, acute liver injury was induced in mice by injection of Con A (20 mg/kg, i.v.). The mice were treated with GW (20 mg/kg, i.p., 30 min after Con A injection) or GW plus the selective CB2R antagonist AM630 (2 mg/kg, i.p., 15 min after Con A injection). We found that Con A caused severe acute liver injury evidenced by significantly increased serum aminotransferase levels, massive hepatocyte apoptosis, and necrosis, as well as lymphocyte infiltration in liver tissues. Treatment with GW significantly ameliorated Con A-induced pathological injury in liver tissue, decreased serum aminotransferase levels, and decreased hepatocyte apoptosis. The therapeutic effects of GW were prevented by AM630. In cell experiments, we showed that CB2Rs were highly expressed in Jurkat T cells, but little expression in L02 liver cells. Treatment with GW (10-40 µg/mL) dose-dependently decreased the viability of Jurkat T cells and induced cell apoptosis, which was reversed by AM630. In the coculture of Jurkat T cells with L02 liver cells, GW dose-dependently protected L02 cells from apoptosis induced by Con A (5 µg/mL). The protective effect of GW was reversed by AM630 (1 µg/mL). Our results suggest that GW protects against Con A-induced acute liver injury in mice by inhibiting Jurkat T-cell proliferation through the CB2Rs.