The macrophage STING-YAP axis controls hepatic steatosis by promoting the autophagic degradation of lipid droplets.

BACKGROUND AND AIMS: The hallmark of NAFLD or hepatic steatosis is characterized by lipid droplet (LD) accumulation in hepatocytes. Autophagy may have profound effects on lipid metabolism and innate immune response. However, how innate immune activation may regulate the autophagic degradation of intracellular LDs remains elusive. APPROACH AND RESULTS: A mouse model of a high-fat diet-induced NASH was used in the myeloid-specific stimulator of interferon genes (STING) knockout or STING/yes-associated protein (YAP) double knockout mice. Liver injury, lipid accumulation, lipid droplet proteins, autophagic genes, chromatin immunoprecipitation coupled with massively parallel sequencing, and RNA-Seq were assessed in vivo and in vitro . We found that high-fat diet-induced oxidative stress activates STING and YAP pathways in hepatic macrophages. The acrophage STING deficiency (myeloid-specific STING knockout) enhances nuclear YAP activity, reduces lipid accumulation, and increases autophagy-related proteins ATG5, ATG7, and light chain 3B but diminishes LD protein perilipin 2 expression. However, disruption of STING and YAP (myeloid STING and YAP double knockout) increases serum alanine aminotransferase and triglyceride levels and reduces ß-fatty acid oxidation gene expression but augments perilipin 2 levels, exacerbating high-fat diet-induced lipid deposition. Chromatin immunoprecipitation coupled with massively parallel sequencing reveals that macrophage YAP targets transmembrane protein 205 and activates AMP-activated protein kinase α, which interacts with hepatocyte mitofusin 2 and induces protein disulfide isomerase activation. Protein disulfide isomerase activates hypoxia-inducible factor-1α signaling, increases autophagosome colocalization with LDs, and promotes the degradation of perilipin 2 by interacting with chaperone-mediated autophagy chaperone HSC70. CONCLUSIONS: The macrophage STING-YAP axis controls hepatic steatosis by reprogramming lipid metabolism in a transmembrane protein 205/mitofusin 2/protein disulfide isomerase-dependent pathway. These findings highlight the regulatory mechanism of the macrophage STING-driven YAP activity on lipid control.

Macrophage PTEN controls STING-induced inflammation and necroptosis through NICD/NRF2 signaling in APAP-induced liver injury.

BACKGROUND: Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signaling has been known to play a critical role in maintaining cellular and tissue homeostasis, which also has an essential role in the inflammatory response. However, it remains unidentified whether and how the macrophage PTEN may govern the innate immune signaling stimulator of interferon genes (STING) mediated inflammation and hepatocyte necroptosis in APAP-induced liver injury (AILI). METHODS: Myeloid-specific PTEN knockout (PTENM-KO) and floxed PTEN (PTENFL/FL) mice were treated with APAP (400 mg/kg) or PBS. In a parallel in vitro study, bone marrow-derived macrophages (BMMs) were isolated from these conditional knockout mice and transfected with CRISPR/Cas9-mediated Notch1 knockout (KO) or CRISPR/Cas9-mediated STING activation vector followed by LPS (100 ng/ml) stimulation. RESULTS: Here, we report that myeloid-specific PTEN knockout (PTENM-KO) mice were resistant to oxidative stress-induced hepatocellular injury with reduced macrophage/neutrophil accumulation and proinflammatory mediators in AILI. PTENM-KO increased the interaction of nuclear Notch intracellular domain (NICD) and nuclear factor (erythroid-derived 2)-like 2 (NRF2) in the macrophage nucleus, reducing reactive oxygen species (ROS) generation. Mechanistically, it is worth noting that macrophage NICD and NRF2 co-localize within the nucleus under inflammatory conditions. Additionally, Notch1 promotes the interaction of immunoglobulin kappa J region (RBPjκ) with NRF2. Disruption of the Notch1 signal in PTEN deletion macrophages, reduced RBPjκ and NRF2 binding, and activated STING signaling. Moreover, PTENM-KO macrophages with STING activated led to ROS generation and TNF-α release, resulting in hepatocyte necroptosis upon co-culture with primary hepatocytes. CONCLUSIONS: Our findings demonstrate that the macrophage PTEN-NICD/NRF2-STING axis is critical to regulating oxidative stress-induced liver inflammation and necroptosis in AILI and implies the therapeutic potential for managing sterile liver inflammation. Video Abstract.

Macrophage Notch1 inhibits TAK1 function and RIPK3-mediated hepatocyte necroptosis through activation of ß-catenin signaling in liver ischemia and reperfusion injury.

BACKGROUND: Notch signaling is highly conserved and critically involved in cell differentiation, immunity, and survival. Activation of the Notch pathway modulates immune cell functions during the inflammatory response. However, it remains unknown whether and how the macrophage Notch1 may control the innate immune signaling TAK1, and RIPK3-mediated hepatocyte necroptosis in liver ischemia and reperfusion injury (IRI). This study investigated the molecular mechanisms of macrophage Notch1 in modulating TAK1-mediated innate immune responses and RIPK3 functions in liver IRI. METHODS: Myeloid-specific Notch1 knockout (Notch1M-KO) and floxed Notch1 (Notch1FL/FL) mice (n = 6/group) were subjected to 90 min partial liver warm ischemia followed by 6 h of reperfusion. In a parallel in vitro study, bone marrow-derived macrophages (BMMs) were isolated from these conditional knockout mice and transfected with CRISPR/Cas9-mediated ß-catenin knockout (KO) vector followed by LPS (100 ng/ml) stimulation. RESULTS: IR stress-induced Notch1 activation evidenced by increased nuclear Notch intracellular domain (NICD) expression in liver macrophages. Myeloid Notch1 deficiency exacerbated IR-induced liver damage, with increased serum ALT levels, macrophage/neutrophil accumulation, and proinflammatory cytokines/chemokines production compared to the Notch1FL/FL controls. Unlike in the Notch1FL/FL controls, Notch1M-KO enhanced TRAF6, TAK1, NF-κB, RIPK3, and MLKL but reduced ß-catenin activation in ischemic livers. However, adoptive transfer of lentivirus ß-catenin-modified macrophages markedly improved liver function with reduced TRAF6, p-TAK1, RIPK3 and p-MLKL in IR-challenged livers. Moreover, disruption of RIPK3 in Notch1M-KO mice with an in vivo mannose-mediated RIPK3 siRNA delivery system diminished IR-triggered hepatocyte death. In vitro studies showed that macrophage NICD and ß-catenin co-localized in the nucleus, whereby ß-catenin interacted with NICD in response to LPS stimulation. Disruption of ß-catenin with a CRISPR/Cas9-mediated ß-catenin KO in Notch1FL/FL macrophage augmented TRAF6 activation leading to enhanced TAK1 function. While CRISPR/Cas9-mediated TRAF6 KO in Notch1M-KO macrophage inhibited RIPK3-mediated hepatocyte necroptosis after co-culture with primary hepatocytes. CONCLUSIONS: Macrophage Notch1 controls TAK1-mediated innate immune responses and RIPK3-mediated hepatocyte necroptosis through activation of ß-catenin. ß-catenin is required for the macrophage Notch1-mediated immune regulation in liver IRI. Our findings demonstrate that the macrophage Notch1-ß-catenin axis is a crucial regulatory mechanism in IR-triggered liver inflammation and provide novel therapeutic potential in organ IRI and transplant recipients. Video abstract.

Pediatric living-donor liver transplantation using right posterior segment grafts.

BACKGROUND: The right posterior segment (RPS) graft was introduced to overcome graft size discrepancy in living donor liver transplantation (LDLT). However, it was very rarely used in pediatric patients. Here we presented 4 pediatric LDLT cases receiving RPS graft between January 2015 and April 2020 in our center. A total of 1868 LDLT procedures were performed in this period. METHODS: Recipients included 1 boy and 3 girls with a median age of 45 months (range from 40 to 93 months). They were diagnosed with progressive familial intrahepatic cholestasis, propionic academia, ornithine transcarbamylase and biliary atresia, respectively. Four donors were all mothers with a median age of 32.5 years (31-38 years). Computer tomography angiography indicated posterior right branches branched off separately from main portal veins (type III variation). Three of these donor livers had 1 orifice of right hepatic veins (RHV). In the remaining 1 donor liver, the RHV showed 3 orifices and an outflow patch plastic was performed. Inferior right hepatic veins weren't found in four donor grafts. The median graft weight was 397.5 g (352-461 g) and the median graft-to-recipient weight ratio was 2.38% (1.44-2.80%). RESULTS: Postoperative complications occurred in neither donors nor recipients. Within the median follow-up duration of 29 months (14-64 months), four children are all alive with normal liver function. CONCLUSION: In summary, for older children weighed more than 15 kg with donors' variation of type III portal veins, the use of RPS grafts could be a feasible and favorable option.

The Foxo1-YAP-Notch1 axis reprograms STING-mediated innate immunity in NASH progression.

Innate immune activation is critical for initiating hepatic inflammation during nonalcoholic steatohepatitis (NASH) progression. However, the mechanisms by which immunoregulatory molecules recognize lipogenic, fibrotic, and inflammatory signals remain unclear. Here, we show that high-fat diet (HFD)-induced oxidative stress activates Foxo1, YAP, and Notch1 signaling in hepatic macrophages. Macrophage Foxo1 deficiency (Foxo1M-KO) ameliorated hepatic inflammation, steatosis, and fibrosis, with reduced STING, TBK1, and NF-κB activation in HFD-challenged livers. However, Foxo1 and YAP double knockout (Foxo1/YAPM-DKO) or Foxo1 and Notch1 double knockout (Foxo1/Notch1M-DKO) promoted STING function and exacerbated HFD-induced liver injury. Interestingly, Foxo1M-KO strongly reduced TGF-ß1 release from palmitic acid (PA)- and oleic acid (OA)-stimulated Kupffer cells and decreased Col1α1, CCL2, and Timp1 expression but increased MMP1 expression in primary hepatic stellate cells (HSCs) after coculture with Kupffer cells. Notably, PA and OA challenge in Kupffer cells augmented LIMD1 and LATS1 colocalization and interaction, which induced YAP nuclear translocation. Foxo1M-KO activated PGC-1α and increased nuclear YAP activity, modulating mitochondrial biogenesis. Using chromatin immunoprecipitation (ChIP) coupled with massively parallel sequencing (ChIP-Seq) and in situ RNA hybridization, we found that NICD colocalizes with YAP and targets Mb21d1 (cGAS), while YAP functions as a novel coactivator of the NICD, which is crucial for reprogramming STING function in NASH progression. These findings highlight the importance of the macrophage Foxo1-YAP-Notch1 axis as a key molecular regulator that controls lipid metabolism, inflammation, and innate immunity in NASH.

Criteria and prognostic models for patients with hepatocellular carcinoma undergoing liver transplantation.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated death globally. Liver transplantation (LT) has emerged as a key treatment for patients with HCC, and the Milan criteria have been adopted as the cornerstone of the selection policy. To allow more patients to benefit from LT, a number of expanded criteria have been proposed, many of which use radiologic morphological characteristics with larger and more tumors as surrogates to predict outcomes. Other groups developed indices incorporating biological variables and dynamic markers of response to locoregional treatment. These expanded selection criteria achieved satisfactory results with limited liver supplies. In addition, a number of prognostic models have been developed using clinicopathological characteristics, imaging radiomics features, genetic data, and advanced techniques such as artificial intelligence. These models could improve prognostic estimation, establish surveillance strategies, and bolster long-term outcomes in patients with HCC. In this study, we reviewed the latest findings and achievements regarding the selection criteria and post-transplant prognostic models for LT in patients with HCC.

Macrophage RIPK3 triggers inflammation and cell death via the XBP1-Foxo1 axis in liver ischaemia-reperfusion injury.

Background & Aims: Receptor-interacting serine/threonine-protein kinase 3 (RIPK3) is a central player in triggering necroptotic cell death. However, whether macrophage RIPK3 may regulate NOD1-dependent inflammation and calcineurin/transient receptor potential cation channel subfamily M member 7 (TRPM7)-induced hepatocyte death in oxidative stress-induced liver inflammatory injury remains elusive. Methods: A mouse model of hepatic ischaemia-reperfusion (IR) injury, the primary hepatocytes, and bone marrow-derived macrophages were used in the myeloid-specific RIPK3 knockout (RIPK3M-KO) and RIPK3-proficient (RIPK3FL/FL) mice. Results: RIPK3M-KO diminished IR stress-induced liver damage with reduced serum alanine aminotransferase/aspartate aminotransferase levels, macrophage/neutrophil infiltration, and pro-inflammatory mediators compared with the RIPK3FL/FL controls. IR stress activated RIPK3, inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α), x-box binding protein 1 (XBP1), nucleotide-binding oligomerisation domain-containing protein 1 (NOD1), NF-κB, forkhead box O1 (Foxo1), calcineurin A, and TRPM7 in ischaemic livers. Conversely, RIPK3M-KO depressed IRE1α, XBP1, NOD1, calcineurin A, and TRPM7 activation with reduced serum tumour necrosis factor α (TNF-α) levels. Moreover, Foxo1M-KO alleviated IR-induced liver injury with reduced NOD1 and TRPM7 expression. Interestingly, chromatin immunoprecipitation coupled with massively parallel sequencing revealed that macrophage Foxo1 colocalised with XBP1 and activated its target gene Zc3h15 (zinc finger CCCH domain-containing protein 15). Activating macrophage XBP1 enhanced Zc3h15, NOD1, and NF-κB activity. However, disruption of macrophage Zc3h15 inhibited NOD1 and hepatocyte calcineurin/TRPM7 activation, with reduced reactive oxygen species production and lactate dehydrogenase release after macrophage/hepatocyte coculture. Furthermore, adoptive transfer of Zc3h15-expressing macrophages in RIPK3M-KO mice augmented IR-triggered liver inflammation and cell death. Conclusions: Macrophage RIPK3 activates the IRE1α-XBP1 pathway and Foxo1 signalling in IR-stress livers. The XBP1-Foxo1 interaction is essential for modulating target gene Zc3h15 function, which is crucial for the control of NOD1 and calcineurin-mediated TRPM7 activation. XBP1 functions as a transcriptional coactivator of Foxo1 in regulating NOD1-driven liver inflammation and calcineurin/TRPM7-induced cell death. Our findings underscore a novel role of macrophage RIPK3 in stress-induced liver inflammation and cell death, implying the potential therapeutic targets in liver inflammatory diseases. Impact and implications: Macrophage RIPK3 promotes NOD1-dependent inflammation and calcineurin/TRPM7-induced cell death cascade by triggering the XBP1-Foxo1 axis and its target gene Zc3h15, which is crucial for activating NOD1 and calcineurin/TRPM7 function, implying the potential therapeutic targets in stress-induced liver inflammatory injury.

PARK7 deficiency inhibits fatty acid ß-oxidation via PTEN to delay liver regeneration after hepatectomy.

BACKGROUND & AIMS: Transient regeneration-associated steatosis (TRAS) is a process of temporary hepatic lipid accumulation and is essential for liver regeneration by providing energy generated from fatty acid ß-oxidation, but the regulatory mechanism underlying TRAS remains unknown. Parkinsonism-associated deglycase (Park7)/Dj1 is an important regulator involved in various liver diseases. In nonalcoholic fatty liver diseased mice, induced by a high-fat diet, Park7 deficiency improves hepatic steatosis, but its role in liver regeneration remains unknown METHODS: Park7 knockout (Park7-/- ), hepatocyte-specific Park7 knockout (Park7△hep ) and hepatocyte-specific Park7-Pten double knockout mice were subjected to 2/3 partial hepatectomy (PHx) RESULTS: Increased PARK7 expression was observed in the regenerating liver of mice at 36 and 48 h after PHx. Park7-/- and Park7△hep mice showed delayed liver regeneration and enhanced TRAS after PHx. PPARa, a key regulator of ß-oxidation, and carnitine palmitoyltransferase 1a (CPT1a), a rate-limiting enzyme of ß-oxidation, had substantially decreased expression in the regenerating liver of Park7△hep mice. Increased phosphatase and tensin homolog (PTEN) expression was observed in the liver of Park7△hep mice, which might contribute to delayed liver regeneration in these mice because genomic depletion or pharmacological inhibition of PTEN restored the delayed liver regeneration by reversing the downregulation of PPARa and CPT1a and in turn accelerating the utilization of TRAS in the regenerating liver of Park7△hep mice CONCLUSION: Park7/Dj1 is a novel regulator of PTEN-dependent fatty acid ß-oxidation, and increasing Park7 expression might be a promising strategy to promote liver regeneration.

Novel role of macrophage TXNIP-mediated CYLD-NRF2-OASL1 axis in stress-induced liver inflammation and cell death.

Background & Aims: The stimulator of interferon genes (STING)/TANK-binding kinase 1 (TBK1) pathway is vital in mediating innate immune and inflammatory responses during oxidative/endoplasmic reticulum (ER) stress. However, it remains unknown whether macrophage thioredoxin-interacting protein (TXNIP) may regulate TBK1 function and cell death pathways during oxidative/ER stress. Methods: A mouse model of hepatic ischaemia/reperfusion injury (IRI), the primary hepatocytes, and bone marrow-derived macrophages were used in the myeloid-specific TXNIP knockout (TXNIPM-KO) and TXNIP-proficient (TXNIPFL/FL) mice. Results: The TXNIPM-KO mice were resistant to ischaemia/reperfusion (IR) stress-induced liver damage with reduced serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels, macrophage/neutrophil infiltration, and pro-inflammatory mediators compared with the TXNIPFL/FL controls. IR stress increased TXNIP, p-STING, and p-TBK1 expression in ischaemic livers. However, TXNIPM-KO inhibited STING, TBK1, interferon regulatory factor 3 (IRF3), and NF-κB activation with interferon-ß (IFN-ß) expression. Interestingly, TXNIPM-KO augmented nuclear factor (erythroid-derived 2)-like 2 (NRF2) activity, increased antioxidant gene expression, and reduced macrophage reactive oxygen species (ROS) production and hepatic apoptosis/necroptosis in IR-stressed livers. Mechanistically, macrophage TXNIP deficiency promoted cylindromatosis (CYLD), which colocalised and interacted with NADPH oxidase 4 (NOX4) to enhance NRF2 activity by deubiquitinating NOX4. Disruption of macrophage NRF2 or its target gene 2',5' oligoadenylate synthetase-like 1 (OASL1) enhanced Ras GTPase-activating protein-binding protein 1 (G3BP1) and TBK1-mediated inflammatory response. Notably, macrophage OASL1 deficiency induced hepatocyte apoptotic peptidase activating factor 1 (APAF1), cytochrome c, and caspase-9 activation, leading to increased caspase-3-initiated apoptosis and receptor-interacting serine/threonine-protein kinase 3 (RIPK3)-mediated necroptosis. Conclusions: Macrophage TXNIP deficiency enhances CYLD activity and activates the NRF2-OASL1 signalling, controlling IR stress-induced liver injury. The target gene OASL1 regulated by NRF2 is crucial for modulating STING-mediated TBK1 activation and Apaf1/cytochrome c/caspase-9-triggered apoptotic/necroptotic cell death pathway. Our findings underscore a novel role of macrophage TXNIP-mediated CYLD-NRF2-OASL1 axis in stress-induced liver inflammation and cell death, implying the potential therapeutic targets in liver inflammatory diseases. Lay summary: Liver inflammation and injury induced by ischaemia and reperfusion (the absence of blood flow to the liver tissue followed by the resupply of blood) is a significant cause of hepatic dysfunction and failure following liver transplantation, resection, and haemorrhagic shock. Herein, we uncover an underlying mechanism that contributes to liver inflammation and cell death in this setting and could be a therapeutic target in stress-induced liver inflammatory injury.

Comprehensive analysis of circular RNAs from steatotic livers after ischemia and reperfusion injury by next-generation RNA sequencing.

Global organ shortage has led to the acceptance of steatotic livers for transplantation, taking the risk of graft dysfunction associated with the higher sensitivity of steatotic livers to ischemia and reperfusion injury (IRI). Data about circular RNAs (circRNAs) in steatotic livers following IRI are practically nonexistent. In our study, a high-fat diet-fed mouse model of hepatic steatosis was generated, and RNA sequencing was performed both on IRI and on sham liver tissues of these mice to screen for circRNAs with significant differential expression. To further validate our bioinformatics data, one upregulated circRNA and four downregulated circRNAs were examined. The circularity of these circRNAs was demonstrated using RNaseR digestion and Sanger sequencing. The expression of four stable circRNAs undigested by RNaseR was further validated by quantitative PCR. In summary, this study unearths several circRNAs as novel and potentially effective targets involved in the more severe damage of steatotic livers following IRI.

Hypothyroidism and its Association with Systemic Lupus Erythematosus: A Cross Sectional Study in Chinese Patients.

BACKGROUND: Specific factors correlated with hypothyroidism in systemic lupus erythematosus (SLE) patients remain unclear. Therefore, we aim to evaluate the prevalence of thyroid dysfunction in Chinese patients with SLE and the relationship between clinical hypothyroidism and SLE. METHODS: We conducted a cross sectional study of the prevalence of thyroid dysfunction in 672 patients with SLE and 605 age- and sex-matched healthy controls. Demographic, clinical, and biochemical data were compared between 58 patients with SLE with hypothyroidism and 197 patients with SLE with euthyroidism. Multivariate analysis was performed using binomial logistic regression analysis. Spearman's rank correlation was used to identify an association between thyroid function and disease activity. RESULTS: The prevalence of thyroid dysfunction was significantly higher in patients with SLE than in controls (70.7% vs 19.7%). SLE was associated with higher rates of hypothyroidism (9.6%, P ≤ 0.001) and euthyroid sick syndrome (49.6%, P ≤ 0.001) compared with control subjects. Further analyses showed that hypothyroidism in patients with SLE was associated with high blood pressure, renal disorder, high serum creatinine, high uric acid, hyperlipidaemia, low C3 and C4, positive anti-dsDNA antibodies, and high SLE disease activity index (SLEDAI) score. In multiple logistic regression models, albumin, platelet count, serum creatinine, and anti-dsDNA antibodies were associated with hypothyroidism. Finally, free tri-iodothyronine was significantly negatively correlated with SLEDAI score. CONCLUSIONS: Hypothyroidism was more prevalent in patients with SLE. There was a relationship between hypothyroidism with renal disorder and lupus activity. Albumin, platelet count, serum creatinine, and anti-dsDNA antibodies were correlated with hypothyroidism.

Bioinformatic Analysis to Identify a Multi-mRNA Signature for the Prediction of Metastasis in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) with metastasis indicates worse prognosis for patients. However, the current methods are insufficient to accurately predict HCC metastasis at early stage. Based on the expression profiles of three Gene Expression Omnibus datasets, the differentially expressed genes associated with HCC metastasis were screened by online analytical tool GEO2R and weighted gene co-expression network analysis. Second, a risk score model including 27-mRNA was established by univariate Cox regression analyses, time-dependent ROC curves and least absolute shrinkage and selection operator Cox regression analysis. Then, we validated the model in cohort The Cancer Genome Atlas-liver hepatocellular carcinoma and analyzed the functions and key signaling pathways of the genes associated with the risk score model. According to the risk score model, patients were divided into two subgroups (high risk and low risk groups). The metastasis rate between two subgroups was significantly different in training cohort (p < 0.0001, hazard ratio [HR]: 10.3, confidence interval [95% CI]: 6.827-15.55) and external validation cohort (p = 0.0008, HR: 1.768, 95% CI: 1.267-2.467). Multivariable analysis showed that the risk score model was superior to and independent of other clinical factors (such as tumor stage, tumor size, and other parameters) in predicting early HCC metastasis. Moreover, the risk score model could predict the overall survival of patients with HCC. Finally, most of 27-mRNA were enriched in exosome and membrane bounded organelle, and these were involved in transportation and metabolic biological process. Protein-protein interaction network analysis showed most of these genes might be key genes affecting the progression of HCC. In addition, 3 genes of 27-mRNA were also differentially expressed in peripheral blood mononuclear cell. In conclusion, by using two combined methods and a broader of HCC datasets, our study provided reliable and superior predictive model for HCC metastases, which will facilitate individual medical management for these high metastatic risk HCC patients.

Non-metabolic role of UCK2 links EGFR-AKT pathway activation to metastasis enhancement in hepatocellular carcinoma.

Up-regulation of Uridine-cytidine kinase 2 (UCK2), a rate-limiting enzyme of the pyrimidine salvage pathway, has been suggested in HCC, but the detailed molecular mechanisms and therapic role of UCK2 remain elusive. Bioinformatic analyses revealed that UCK2 might be a key up-regulated metabolic gene in HCCs. The expressional pattern and prognostic value of UCK2 were further examined in a large number of clinical samples. Functional assays based on site-directed mutagenesis showed that UCK2 promoted cell proliferation in a metabolic manner, but non-catalytically facilitates HCC metastasis. Mechanistically, in response to EGF, UCK2 interacted with EGFR to block EGF-induced EGFR ubiquitination and degradation, which resulted in elevated EGFR-AKT pathway activation and metastasis enhancement in HCCs. Concurrent pharmacological targeting on UCK2 and EGFR showed synergistic effects on HCC treatment. This study disclosed the non-metabolic role of UCK2 and suggested the therapeutic potential of concurrent blocking the metabolic and non-metabolic roles of UCK2 in HCC treatment.

Blocking GSDMD processing in innate immune cells but not in hepatocytes protects hepatic ischemia-reperfusion injury.

Pyroptosis, a proinflammatory form of programmed cell death, plays important roles in the pathogenesis of many diseases. Inflammasome activation, which has been shown in hepatic ischemia-reperfusion injury (IRI), is demonstrated to be closely associated with pyroptosis, indicating that pyroptosis may occur and perform functions in hepatic IRI. However, there is no direct evidence showing the function of pyroptosis in hepatic IRI. In this study, by detecting the pyroptosis markers, we showed that pyroptosis may be induced during hepatic IRI. Furthermore, by adopting caspase-1 inhibitors, we showed that inhibition of pyroptosis could significantly ameliorate liver injury and suppress inflammatory response during hepatic IRI. Interestingly, caspase-1 inhibitors have no protective effects on in vitro hepatocytes under hypoxic reoxygenation condition. To investigate pyroptosis induced in which specific cell types may affect hepatic IRI, we generated hepatocyte-specific Gsdmd-knockout (Hep-Gsdmd-/-) and myeloid-specific Gsdmd-knockout (LysmCre+Gsdmdf/f) mice. Functional experiments showed that compared to control mice (Gsdmdf/f), there were alleviated liver injury and inflammation in LysmCre+Gsdmdf/f mice, but not in AlbCre+Gsdmdf/f mice. In parallel in vitro studies, cytokine expression and production decreased in bone-marrow-derived macrophages and Kupffer cells from LysmCre+Gsdmdf/f mice compared to their controls. Our findings demonstrated that pyroptosis in innate immune cells aggravates hepatic IRI and implied that hepatic IRI could be protected by blocking pyroptosis, which may become a potential therapeutic target in the clinic.

Prognostic values of a novel multi-mRNA signature for predicting relapse of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an epithelial cancer and has high death and recurrence rates, current methods cannot satisfy the need for predicting cancer relapse effectively. So, we aimed at conducting a multi-mRNA signature to improve the relapse prediction of CCA. We analyzed mRNA expression profiling in large CCA cohorts from the Gene Expression Omnibus (GEO) database (GSE76297, GSE32879, GSE26566, GSE31370, and GSE45001) and The Cancer Genome Atlas (TCGA) database. The Least absolute shrinkage and selection operator (LASSO) regression model was used to establish a 7-mRNA-based signature that was significantly related to the recurrence-free survival (RFS) in two test series. Based on the 7-mRNA signature, the cohort TCGA patients could be divided into high-risk or low-risk subgroups with significantly different RFS [p < 0.001, hazard ratio (HR): 48.886, 95% confidence interval (CI): 6.226-3.837E+02]. Simultaneously, the prognostic value of the 7-mRNA signature was confirmed in clinical samples of Ren Ji hospital (p < 0.001, HR: 4.558, 95% CI: 1.829-11.357). Further analysis including multivariable and sub-group analyses revealed that the 7-mRNA signature was an independent prognostic value for recurrence of patients with CCA. In conclusion, our results might provide an efficient tool for relapse prediction and were beneficial to individualized management for CCA patients.