A Protein Complex of Liver Origin Activates a Pro-inflammatory Program That Drives Hepatic and Intestinal Injury in Alcohol-Associated Liver Disease.

BACKGROUND & AIMS: There is limited information on how the liver-to-gut axis contributes to alcohol-associated liver disease (AALD). We previously identified that high-mobility group box-1 (HMGB1) undergoes oxidation in hepatocytes and demonstrated elevated serum levels of oxidized HMGB1 ([O] HMGB1) in alcoholic patients. Since interleukin-1 beta (IL-1B) increases in AALD, we hypothesized hepatocyte-derived [O] HMGB1 could interact with IL-1B to activate a pro-inflammatory program that, besides being detrimental to the liver, drives intestinal barrier dysfunction. RESULTS: Alcohol-fed RageΔMye mice exhibited decreased nuclear factor kappa B signaling, a pro-inflammatory signature, and reduced total intestinal permeability, resulting in protection from AALD. In addition, [O] HMGB1 bound and signaled through the receptor for advanced-glycation end-products (RAGE) in myeloid cells, driving hepatic inflammation, intestinal permeability, and increased portal blood lipopolysaccharide in AALD. We identified that [O] HMGB1 formed a complex with IL-1B, which was found in the livers of patients with acute alcoholic hepatitis and mice with AALD. This complex originated from the liver, because it was absent in the intestine when hepatocytes did not produce [O] HMGB1. Mechanistically, the complex bound RAGE in Kupffer cells and macrophages induced a pro-inflammatory program. Moreover, it bound RAGE in intestinal macrophages and epithelial cells, leading to intestinal inflammation, altered intestinal epithelial cell tight junction protein expression, increased intestinal permeability, and elevated portal blood lipopolysaccharide, enhancing AALD pathogenesis. CONCLUSIONS: We identified a protein complex of liver origin that amplifies the pro-inflammatory feedback loop in AALD; therefore, targeting this complex could have significant therapeutic potential.

Ablation of secreted phosphoprotein-1 in hepatocytes increases fatty acid oxidation and ameliorates alcohol-associated liver disease.

BACKGROUND: Previously, we demonstrated that Spp1-/- mice exhibit a greater susceptibility to alcohol-induced liver injury than wild-type (WT) mice. Notably, alcohol triggers the expression of osteopontin (encoded by SPP1) in hepatocytes. However, the specific role of hepatocyte-derived SPP1 in either mitigating or exacerbating alcohol-associated liver disease (AALD) has yet to be elucidated. We hypothesized that hepatocyte-derived SPP1 plays a role in AALD by modulating the regulation of steatosis. METHODS: We analyzed hepatic SPP1 expression using four publicly available datasets from patients with alcoholic hepatitis (AH). Additionally, we examined SPP1 expression in the livers of WT mice subjected to either a control or ethanol Lieber-DeCarli (LDC) diet for 6 weeks. We compared the relationship between SPP1 expression and significantly dysregulated genes in AH with controls using correlation and enrichment analyses. To investigate the specific impact of hepatocyte-derived SPP1, we generated hepatocyte-specific Spp1 knock-out (Spp1ΔHep) mice and subjected them to either a control or ethanol Lieber-DeCarli diet for 6 weeks. RESULTS: Alcohol induced hepatic SPP1 expression in both humans and mice. Our analysis, focusing on genes correlated with SPP1, revealed an enrichment of fatty acid oxidation (FAO) in three datasets, and peroxisome proliferator-activated receptor signaling in one dataset. Notably, FAO genes correlating with SPP1 were downregulated in patients with AH. Ethanol-fed WT mice exhibited higher serum-free fatty acids (FFAs), adipose tissue lipolysis, and hepatic fatty acid (FA) transporters. In contrast, ethanol-fed Spp1ΔHep mice displayed lower liver triglycerides, FFAs, and serum alanine transaminase and greater FAO gene expression than WT mice, indicating a protective effect against AALD. Primary hepatocytes from Spp1∆Hep mice exhibited heightened expression of genes encoding proteins involved in FAO. CONCLUSIONS: Alcohol induces the expression of SPP1 in hepatocytes, leading to impaired FAO and contributing to the development of AALD.

Basiliximab Induction and Postoperative Steroid-free Immunosuppression With Tacrolimus in Pediatric Liver Transplantation: A Randomized Clinical Trial.

BACKGROUND: Optimizing the immunosuppressive regimen is essential to improve the long-term outcomes of pediatric liver transplant recipients. METHODS: We conducted a prospective, randomized, open-label study to compare the safety and efficacy of 2 treatment approaches during pediatric liver transplantation: tacrolimus monotherapy following basiliximab induction (the study group) and a dual regimen of tacrolimus plus steroids (the control group). A total of 150 patients were enrolled, with 75 patients allocated to each group. RESULTS: In both groups, recipients achieved graft and recipient overall survival rates exceeding 93%, with no statistically significant differences between them. However, the study group exhibited a significantly lower incidence of acute cellular rejection (ACR), delayed occurrence of ACR, and an improved ACR-free survival rate at 2 y compared with the control group. Notably, the study group also showed a significant reduction in the incidence of de novo donor-specific antibodies at 3-mo and 2-y posttransplant. Furthermore, 6 mo after the transplant, the study group demonstrated significant improvements in weight-for-age Z score and height-for-age Z score. No notable differences were observed in postoperative complications or the incidence of liver fibrosis between the 2 groups. CONCLUSIONS: Basiliximab induction combine with tacrolimus (TAC) monotherapy is a safe and effective immunosuppressive regimen to reduce the episodes of ACR without influencing the development of liver fibrosis and graft and recipient survival rate after pediatric liver transplantation.

Redox-sensitive high-mobility group box-1 isoforms contribute to liver fibrosis progression and resolution in mice.

BACKGROUND & AIMS: High-mobility group box-1 (HMGB1) significantly increases and undergoes post-translational modifications (PTMs) in response to liver injury. Since oxidative stress plays a major role in liver fibrosis and induces PTMs in proteins, we hypothesized that redox-sensitive HMGB1 isoforms contribute to liver fibrosis progression and resolution. METHODS: We used ESI-LC-MS (electrospray ionization-liquid chromatography-mass spectrometry) to study PTMs of HMGB1 during fibrosis progression and resolution. Conditional knockout mice were used for functional analyses. RESULTS: We identified that disulfide ([O]) and sulfonated ([SO3]) HMGB1 increase during carbon tetrachloride-induced liver fibrosis progression, however, while [O] HMGB1 declines, [SO3] HMGB1 drops but remains, during fibrosis resolution. Conditional knockout of Hmgb1 revealed that production of [O] and [SO3] HMGB1 occurs mostly in hepatocytes. Co-injection of [O] HMGB1 worsens carbon tetrachloride-induced liver fibrosis more than co-injection of [H] HMGB1. Conversely, ablation of [O] Hmgb1 in hepatocytes reduces liver fibrosis. Moreover, ablation of the receptor for advanced-glycation end-products (Rage) reveals that the profibrogenic effect of [O] HMGB1 is mediated by RAGE signaling in hepatic stellate cells (HSCs). Notably, injection of [SO3] HMGB1 accelerates fibrosis resolution due to RAGE-dependent stimulation of HSC apoptosis. Importantly, gene signatures activated by redox-sensitive HMGB1 isoforms in mice, classify patients with fibrosis according to fibrosis and inflammation scores. CONCLUSION: Dynamic changes in hepatocyte-derived [O] and [SO3] HMGB1 signal through RAGE-dependent mechanisms on HSCs to drive their profibrogenic phenotype and fate, contributing to progression and resolution of liver fibrosis. IMPACT AND IMPLICATIONS: Since oxidative stress plays a major role in liver fibrosis and induces post-translational modifications of proteins, we hypothesized that redox-sensitive HMGB1 isoforms contribute to liver fibrosis progression and resolution. This study is significant because a rise in [H] HMGB1 could flag 'patient at risk', the presence of [O] HMGB1 could suggest 'disease in progress or active scarring', while the appearance of [SO3] HMGB1 could point at 'resolution under way'. The latter could be used as a readout for response to pharmacological intervention with anti-fibrotic agents.

Overexpression of HMGB1 in hepatocytes accelerates PTEN inactivation-induced liver cancer.

BACKGROUND: Liver cancer is increasing due to the rise in metabolic dysfunction-associated steatohepatitis (MASH). High-mobility group box-1 (HMGB1) is involved in the pathogenesis of chronic liver disease, but its role in MASH-associated liver cancer is unknown. We hypothesized that an increase in hepatocyte-derived HMGB1 in a mouse model of inactivation of PTEN that causes MASH could promote MASH-induced tumorigenesis. METHODS: We analyzed publicly available transcriptomics datasets, and to explore the effect of overexpressing HMGB1 in cancer progression, we injected 1.5-month-old Pten∆Hep mice with adeno-associated virus serotype-8 (AAV8) vectors to overexpress HMGB1-EGFP or EGFP, and sacrificed them at 3, 9 and 11 months of age. RESULTS: We found that HMGB1 mRNA increases in human MASH and MASH-induced hepatocellular carcinoma (MASH-HCC) compared to healthy livers. Male and female Pten∆Hep mice overexpressing HMGB1 showed accelerated liver tumor development at 9 and 11 months, respectively, with increased tumor size and volume, compared to control Pten∆Hep mice. Moreover, Pten∆Hep mice overexpressing HMGB1, had increased incidence of mixed HCC-intrahepatic cholangiocarcinoma (iCCA). All iCCAs were positive for nuclear YAP and SOX9. Male Pten∆Hep mice overexpressing HMGB1 showed increased cell proliferation and F4/80+ cells at 3 and 9 months. CONCLUSION: Overexpression of HMGB1 in hepatocytes accelerates liver tumorigenesis in Pten∆Hep mice, enhancing cell proliferation and F4/80+ cells to drive MASH-induced liver cancer.

Serum CXCL8 Concentration Can Be Used as a Noninvasive Marker of Subclinical Rejection After Pediatric Liver Transplantation.

BACKGROUND: This study aimed to explore whether serum CXCL8 concentration can be used as a noninvasive marker of subclinical rejection (SCR) after pediatric liver transplantation (pLT). METHODS: Firstly, RNA sequencing (RNA-seq) was performed on 22 protocol liver biopsy samples. Secondly, several experimental methods were used to verify the RNA-seq results. Finally, the clinical data and serum samples of 520 LT patients in the Department of Pediatric Transplantation of Tianjin First Central Hospital from January 2018 to December 2019 were collected. RESULTS: RNA-seq results indicated that CXCL8 was significantly increased in the SCR group. The results of the 3 experimental methods were consistent with RNA-seq results. According to the 1:2 propensity score matching, 138 patients were divided into the SCR (n = 46) and non-SCR (n = 92) groups. Serological test results indicated that there was no difference in preoperative CXCL8 concentration between the SCR and non-SCR groups ( P > 0.05). However, during protocol biopsy, CXCL8 in the SCR group was significantly higher than in the non-SCR group ( P < 0.001). In diagnosing SCR, receiver operating characteristic curve analysis showed that the area under the curve of CXCL8 was 0.966 (95% confidence interval, 0.938-0.995), sensitivity was 95%, and specificity was 94.6%. In differentiating nonborderline from borderline rejection, the area under the curve of CXCL8 was 0.853 (95% confidence interval, 0.718-0.988), sensitivity was 86.7%, and specificity was 94.6%. CONCLUSIONS: This study demonstrates that serum CXCL8 concentration has high accuracy for the diagnosis and disease stratification of SCR after pLT.

Metronomic capecitabine inhibits liver transplant rejection in rats by triggering recipients' T cell ferroptosis.

BACKGROUND: Capecitabine (CAP) is a classic antimetabolic drug and has shown potential antirejection effects after liver transplantation (LT) in clinical studies. Our previous study showed that metronomic CAP can cause the programmed death of T cells by inducing oxidative stress in healthy mice. Ferroptosis, a newly defined non-apoptotic cell death that occurs in response to iron overload and lethal levels of lipid peroxidation, is an important mechanism by which CAP induces cell death. Therefore, ferroptosis may also play an important role in CAP-induced T cell death and play an immunosuppressive role in acute rejection after trans-plantation. AIM: To investigate the functions and underlying mechanisms of antirejection effects of metronomic CAP. METHODS: A rat LT model of acute rejection was established, and the effect of metronomic CAP on splenic hematopoietic function and acute graft rejection was evaluated 7 d after LT. In vitro, primary CD3+ T cells were sorted from rat spleens and human peripheral blood, and co-cultured with or without 5-fluorouracil (5-FU) (active agent of CAP). The levels of ferroptosis-related proteins, ferrous ion concentration, and oxidative stress-related indicators were observed. The changes in mito-chondrial structure were observed using electron microscopy. RESULTS: With no significant myelotoxicity, metronomic CAP alleviated graft injury (Banff score 9 vs 7.333, P < 0.001), prolonged the survival time of the recipient rats (11.5 d vs 16 d, P < 0.01), and reduced the infiltration rate of CD3+ T cells in peripheral blood (6.859 vs 3.735, P < 0.001), liver graft (7.459 vs 3.432, P < 0.001), and spleen (26.92 vs 12.9, P < 0.001), thereby inhibiting acute rejection after LT. In vitro, 5-FU, an end product of CAP metabolism, induced the degradation of the ferritin heavy chain by upregulating nuclear receptor coactivator 4, which caused the accumulation of ferrous ions. It also inhibited nuclear erythroid 2 p45-related factor 2, heme oxygenase-1, and glutathione peroxidase 4, eventually leading to oxidative damage and ferroptosis of T cells. CONCLUSION: Metronomic CAP can suppress acute allograft rejection in rats by triggering CD3+ T cell ferroptosis, which makes it an effective immunosuppressive agent after LT.

Safety and Effectiveness of Rasagiline in Chinese Patients with Parkinson's Disease: A Prospective, Multicenter, Non-interventional Post-marketing Study.

INTRODUCTION: Rasagiline is indicated for treating idiopathic Parkinson's disease (PD) as monotherapy and adjunct therapy to levodopa in patients. OBJECTIVES: To assess the post-marketing safety and tolerability of rasagiline in Chinese PD patients, as well as its effectiveness in improving motor symptoms. METHODS: This prospective, non-interventional, multicenter, cohort study included PD patients administered rasagiline monotherapy or adjunct therapy to levodopa. The primary outcome was the incidence of adverse drug reactions (ADRs) according to MedDRA® (version 22.0), and the secondary outcomes were the Parkinson's Disease Unified Rating Scale (UPDRS) part III, Clinical Global Impression-Severity (CGI-S), and Clinical Global Impression-Global-Improvement (CGI-I), assessed at Weeks 4, 12, and 24. RESULTS: In total, 734 patients, 95 in the monotherapy subgroup and 639 in the adjunct therapy subgroup, were included in the safety population. The incidence rates of all ADRs were comparable between the monotherapy (15.8%) and adjunct therapy (13.6%) subgroups. The most common ADRs by system organ class were nervous system disorders (5.6%), gastrointestinal disorders (3.3%), psychiatric disorders (1.8%), vascular disorders (1.2%), and general disorders and administration site conditions (1.1%). Five (0.7%) participants experienced 5 serious ADRs. Improvements in UPDRS part III, CGI-S and CGI-I at Weeks 4, 12 and 24 from baseline were observed. CONCLUSIONS: Safety data in this study indicated no extra safety concerns. Rasagiline is generally safe and well tolerated in Chinese PD patients. The safety profile and tolerability were in line with the established safety profile. Moreover, rasagiline reduced the severity of PD motor symptoms, confirming findings by previous clinical trials.

Macrophage-derived Osteopontin (SPP1) Protects From Nonalcoholic Steatohepatitis.

BACKGROUND & AIMS: Nonalcoholic steatohepatitis (NASH) is characterized by steatosis, lobular inflammation, hepatocyte ballooning degeneration, and fibrosis, all of which increase the risk of progression to end-stage liver disease. Osteopontin (OPN, SPP1) plays an important role in macrophage (MF) biology, but whether MF-derived OPN affects NASH progression is unknown. METHODS: We analyzed publicly available transcriptomic datasets from patients with NASH, and used mice with conditional overexpression or ablation of Spp1 in myeloid cells and liver MFs, and fed them a high-fat, fructose, and cholesterol diet mimicking the Western diet, to induce NASH. RESULTS: This study demonstrated that MFs with high expression of SPP1 are enriched in patients and mice with nonalcoholic fatty liver disease (NAFLD), and show metabolic but not pro-inflammatory properties. Conditional knockin of Spp1 in myeloid cells (Spp1KI Mye) or in hepatic macrophages (Spp1KI LvMF) conferred protection, whereas conditional knockout of Spp1 in myeloid cells (Spp1ΔMye) worsened NASH. The protective effect was mediated by induction of arginase-2 (ARG2), which enhanced fatty acid oxidation (FAO) in hepatocytes. Induction of ARG2 stemmed from enhanced production of oncostatin-M (OSM) in MFs from Spp1KI Mye mice. OSM activated STAT3 signaling, which upregulated ARG2. In addition to hepatic effects, Spp1KI Mye also protected through sex-specific extrahepatic mechanisms. CONCLUSION: MF-derived OPN protects from NASH, by upregulating OSM, which increases ARG2 through STAT3 signaling. Further, the ARG2-mediated increase in FAO reduces steatosis. Therefore, enhancing the OPN-OSM-ARG2 crosstalk between MFs and hepatocytes may be beneficial for patients with NASH.

Deficiency of neutrophil high-mobility group box-1 in liver transplant recipients exacerbates early allograft injury in mice.

BACKGROUND AND AIMS: Early allograft dysfunction (EAD) is a severe event leading to graft failure after liver transplant (LT). Extracellular high-mobility group box-1 (HMGB1) is a damage-associated molecular pattern that contributes to hepatic ischemia-reperfusion injury (IRI). However, the contribution of intracellular HMGB1 to LT graft injury remains elusive. We hypothesized that intracellular neutrophil-derived HMGB1 from recipients protects from post-LT EAD. APPROACH AND RESULTS: We generated mice with conditional ablation or overexpression of Hmgb1 in hepatocytes, myeloid cells, or both. We performed LTs and injected lipopolysaccharide (LPS) to evaluate the effect of intracellular HMGB1 in EAD. Ablation of Hmgb1 in hepatocytes and myeloid cells of donors and recipients exacerbated early allograft injury after LT. Ablation of Hmgb1 from liver grafts did not affect graft injury; however, lack of Hmgb1 from recipient myeloid cells increased reactive oxygen species (ROS) and inflammation in liver grafts and exacerbated injury. Neutrophils lacking HMGB1 were more activated, showed enhanced pro-oxidant and pro-inflammatory signatures, and reduced biosynthesis and metabolism of inositol polyphosphates (InsPs). On LT reperfusion or LPS treatment, there was significant neutrophil mobilization and infiltration into the liver and enhanced production of ROS and pro-inflammatory cytokines when intracellular Hmgb1 was absent. Depletion of neutrophils using anti-Ly6G antibody attenuated graft injury in recipients with myeloid cell Hmgb1 ablation. CONCLUSIONS: Neutrophil HMGB1 derived from recipients is central to regulate their activation, limits the production of ROS and pro-inflammatory cytokines, and protects from early liver allograft injury.

Matrisome gene-based subclassification of patients with liver fibrosis identifies clinical and molecular heterogeneities.

BACKGROUND AIMS: Excessive deposition and crosslinking of extracellular matrix increases liver density and stiffness, promotes fibrogenesis, and increases resistance to fibrinolysis. An emerging therapeutic opportunity in liver fibrosis is to target the composition of the extracellular matrix or block pathogenic communication with surrounding cells. However, the type and extent of extracellular changes triggering liver fibrosis depend on the underlying etiology. Our aim was to unveil matrisome genes not dependent on etiology, which are clinically relevant to liver fibrosis. APPROACH RESULTS: We used transcriptomic profiles from liver fibrosis cases of different etiologies to identify and validate liver fibrosis-specific matrisome genes (LFMGs) and their clinical and biological relevance. Dysregulation patterns and cellular landscapes of LFMGs were further explored in mouse models of liver fibrosis progression and regression by bulk and single-cell RNA sequencing. We identified 35 LFMGs, independent of etiology, representing an LFMG signature defining liver fibrosis. Expression of the LFMG signature depended on histological severity and was reduced in regressive livers. Patients with liver fibrosis, even with identical pathological scores, could be subclassified into LFMG Low and LFMG High , with distinguishable clinical, cellular, and molecular features. Single-cell RNA sequencing revealed that microfibrillar-associated protein 4 + activated HSC increased in LFMG High patients and were primarily responsible for the LFMG signature expression and dysregulation. CONCLUSIONS: The microfibrillar-associated protein 4 + -activated HSC-derived LFMG signature classifies patients with liver fibrosis with distinct clinical and biological characteristics. Our findings unveil hidden information from liver biopsies undetectable using traditional histologic assessments.

Hepatocellular carcinomas, exhibiting intratumor fibrosis, express cancer-specific extracellular matrix remodeling and WNT/TGFB signatures, associated with poor outcome.

BACKGROUND AND AIMS: HCC, the third leading cause of cancer-related death, arises in the context of liver fibrosis. Although HCC is generally poorly fibrogenic, some tumors harbor focal intratumor extracellular matrix (ECM) deposits called "fibrous nests." To date, the molecular composition and clinical relevance of these ECM deposits have not been fully defined. APPROACH AND RESULTS: We performed quantitative matrisome analysis by tandem mass tags mass spectrometry in 20 human cancer specific matrisome (HCCs) with high or low-grade intratumor fibrosis and matched nontumor tissues, as well as in 12 livers from mice treated with vehicle, carbon tetrachloride, or diethylnitrosamine. We found 94 ECM proteins differentially abundant between high and low-grade fibrous nests, including interstitial and basement membrane components, such as several collagens, glycoproteins, proteoglycans, enzymes involved in ECM stabilization and degradation, and growth factors. Pathway analysis revealed a metabolic switch in high-grade fibrosis, with enhanced glycolysis and decreased oxidative phosphorylation. Integrating the quantitative proteomics with transcriptomics from HCCs and nontumor livers (n = 2,285 samples), we identified a subgroup of fibrous nest HCCs, characterized by cancer-specific ECM remodeling, expression of the WNT/TGFB (S1) subclass signature, and poor patient outcome. Fibrous nest HCCs abundantly expressed an 11-fibrous-nest - protein signature, associated with poor patient outcome, by multivariate Cox analysis, and validated by multiplex immunohistochemistry. CONCLUSIONS: Matrisome analysis highlighted cancer-specific ECM deposits, typical of the WNT/TGFB HCC subclass, associated with poor patient outcomes. Hence, histologic reporting of intratumor fibrosis in HCC is of clinical relevance.

Incidence and risk factors of subclinical rejection after pediatric liver transplantation, and impact on allograft fibrosis.

INTRODUCTION: Subclinical rejection (SCR) is a common injury in protocol biopsy after pediatric liver transplantation (pLT), but its effect on the recipient is not clearly understood. We herein investigated the incidence and risk factors involved in SCR and analyzed the relationship between SCR and allograft fibrosis (AF). METHODS: We retrospectively reviewed the biopsy results from 507 children between May 2013 and May 2019, and 352 patients underwent protocol biopsy 2 years after pLT, 203 underwent protocol biopsy 5 years after pLT, and 48 underwent protocol biopsy both 2 and 5 years after pLT. RESULTS: The incidence of SCR in the 5-year group was higher than that in the 2-year group (20.2% vs.13.4%, respectively, p = .033). The number of patients with mild and moderate SCR in the 5-year group was also higher than that in the 2-year group (p = .039). Logistic regression analysis showed that acute rejection before liver biopsy and deceased donor liver transplantation (DDLT) were independent risk factors for SCR in the two groups, and that the incidence and severity of AF in protocol biopsies at both periods in the SCR group were higher than those in the non-SCR group (p < .05). CONCLUSIONS: The incidence and severity of SCR increased with the prolongation of protocol biopsy time. We postulate that acute rejection and DDLT are independent risk factors for SCR after transplantation. As the occurrence of SCR also augmented the incidence and severity of AF.

Outcome of split-liver transplantation from pediatric donors weighing 25 kg or less.

The lower limit of body weight for "splitable" liver grafts remains unknown. To examine the outcome of split-liver transplantation (SLT) from pediatric donors ≤25 kg relative to conventional graft-type liver transplantation from deceased donors under corresponding conditions, a total of 158 patients who received primary liver transplantation, including 22 SLTs from donors ≤25 kg, 46 SLTs from donors >25 kg, 76 whole-liver transplantations, and 14 reduced-liver transplantations in donors ≤25 kg between January 2018 and December 2019, were included in the study. There was no significant difference in the complications, patient survival, and graft survival between each of the latter three groups and the SLT ≤25 kg group. Pediatric End-Stage Liver Disease (PELD) score was the independent predictor of graft loss (death or retransplantation). Graft weight was the independent predictor of hepatic artery thrombosis. SLT using well-selected pediatric donors ≤25 kg is an effective strategy to increase organ availability, especially for low-body-weight recipients, compared with conventional graft type from deceased donors under the condition of corresponding donor weight without increasing morbidity and mortality.

Intrabiliary infusion of naked DNA vectors targets periportal hepatocytes in mice.

Hydrodynamic tail vein injection (HTV) is the "gold standard" for delivering naked DNA vectors to mouse liver, thereby transfecting predominately perivenous hepatocytes. While HTV corrects metabolic liver defects such as phenylketonuria or cystathionine ß-synthase deficiency, correction of spf ash mice with ornithine transcarbamylase (OTC) deficiency was not possible despite overexpression in the liver, as the OTC enzyme is primarily expressed in periportal hepatocytes. To target periportal hepatocytes, we established hydrodynamic retrograde intrabiliary injection (HRII) in mice and optimized minicircle (MC) vector delivery using luciferase as a marker gene. HRII resulted in a transfection efficiency below 1%, 100-fold lower than HTV. While HRII induced minimal liver toxicity compared with HTV, overexpression of luciferase by both methods, but not of a natural liver-specific enzyme, elicited an immune response that led to the elimination of luciferase expression. Further testing of MC vectors delivered via HRII in spf ash mice did not result in sufficient therapeutic efficacy and needs further optimization and/or selection of the corrected cells. This study reveals that luciferase expression is toxic for the liver. Furthermore, physical delivery of MC vectors via the bile duct has the potential to treat defects restricted to periportal hepatocytes, which opens new doors for non-viral liver-directed gene therapy.

HBsAg seroconversion in de novo hepatitis B virus-infected paediatric liver transplant recipients with anti-viral therapy.

We investigated the clinical characteristics and therapeutic strategies for paediatric liver transplant (PLT) recipients who experienced de novo hepatitis B virus infection and the features of HBsAg seroconversion. A total of 821 PLT were performed in HBV-free recipients between January 2013 and January 2019 in Paediatric Organ Transplant Center, Tianjin First Central Hospital. Twenty-one recipients developed de novo HBV infection, the clinical data were analysed. The overall incidence of de novo HBV infection was 2.5%. Only one recipient received an HBcAb-negative graft, 20 recipients received HBcAb-positive grafts. The incidence of de novo HBV infection in HBcAb-negative and HBcAb-positive graft recipients were 0.2% and 6.3%, respectively. Fifteen de novo HBV-infected recipients showed HBsAg seroconversion, the incidence of HBsAg seroconversion was 71.4%. The median time from the diagnosis of de novo HBV infection to HBsAg seroconversion was 15 (1, 73) months. Recipients with hepatitis B surface antigen (HBsAg) titre <1000 IU/L and negative hepatitis B e antigen (HBeAg) at the time of de novo HBV infection diagnosis were more likely to achieve HBsAg seroconversion. Nucleotide analogues were effective in treating recipients with de novo HBV infection. De novo HBV infection does not impact liver graft function as well as recipient and graft survival rate. De novo HBV infection does not impact PLT recipient outcomes under close monitoring and appropriate treatment. High incidence of HBsAg seroconversion can be achieved after anti-viral therapy.

Intestinal Osteopontin Protects From Alcohol-induced Liver Injury by Preserving the Gut Microbiome and the Intestinal Barrier Function.

BACKGROUND & AIMS: The gut-liver axis plays a key role in the pathogenesis of alcohol-associated liver disease (ALD). We demonstrated that Opn-/- develop worse ALD than wild-type (WT) mice; however, the role of intestinal osteopontin (OPN) in ALD remains unknown. We hypothesized that overexpression of OPN in intestinal epithelial cells (IECs) could ameliorate ALD by preserving the gut microbiome and the intestinal barrier function. METHODS: OpnKI IEC, OpnΔIEC, and WT mice were fed control or ethanol Lieber-DeCarli diet for 6 weeks. RESULTS: OpnKI IEC but not OpnΔIEC mice showed improved intestinal barrier function and protection from ALD. There were less pathogenic and more beneficial bacteria in ethanol-fed OpnKI IEC than in WT mice. Fecal microbiome transplant (FMT) from OpnKI IEC to WT mice protected from ALD. FMT from ethanol-fed WT to OpnKI IEC mice failed to induce ALD. Antimicrobial peptides, Il33, pSTAT3, aryl hydrocarbon receptor (Ahr), and tight-junction protein expression were higher in IECs from jejunum of ethanol-fed OpnKI IEC than of WT mice. Ethanol-fed OpnKI IEC showed more tryptophan metabolites and short-chain fatty acids in portal serum than WT mice. FMT from OpnKI IEC to WT mice enhanced IECs Ahr and tight-junction protein expression. Oral administration of milk OPN replicated the protective effect of OpnKI IEC mice in ALD. CONCLUSION: Overexpression of OPN in IECs or administration of milk OPN maintain the intestinal microbiome by intestinal antimicrobial peptides. The increase in tryptophan metabolites and short-chain fatty acids signaling through the Ahr in IECs, preserve the intestinal barrier function and protect from ALD.

Ablation of high-mobility group box-1 in the liver reduces hepatocellular carcinoma but causes hyperbilirubinemia in Hippo signaling-deficient mice.

Silencing the Hippo kinases mammalian sterile 20-like 1 and 2 (MST1/2) activates the transcriptional coactivator yes-associated protein (YAP) in human hepatocellular carcinoma (HCC). Hepatocyte-derived high-mobility group box-1 (HMGB1) regulates YAP expression; however, its contribution to HCC in the context of deregulated Hippo signaling is unknown. Here, we hypothesized that HMGB1 is required for hepatocarcinogenesis by activating YAP in Hippo signaling-deficient (Mst1/2ΔHep ) mice. Mst1/2ΔHep mice developed HCC within 3.5 months of age and had increased hepatic expression of HMGB1 and elevated YAP activity compared to controls. To understand the contribution of HMGB1, we generated Mst1/2&Hmgb1ΔHep mice. They exhibited decreased YAP activity, cell proliferation, inflammation, fibrosis, atypical ductal cell expansion, and HCC burden at 3.5 months compared to Mst1/2∆Hep mice. However, Mst1/2&Hmgb1ΔHep mice were smaller, developed hyperbilirubinemia, had more liver injury with intrahepatic biliary defects, and had reduced hemoglobin compared to Mst1/2ΔHep mice. Conclusion: Hepatic HMGB1 promotes hepatocarcinogenesis by regulation of YAP activity; nevertheless, it maintains intrahepatic bile duct physiology under Hippo signaling deficiency.

Outflow reconstruction of left lateral graft with two widely spaced hepatic veins in pediatric living donor liver transplantation.

BACKGROUND: Living donor liver transplantation using the left lateral segment of the liver is the most common type of pediatric liver transplantation. An appropriate surgical approach is crucial for decreasing the risk of vascular complications using these grafts with anatomical variations. METHODS: Between January 2017 and December 2020, 631 living donor liver transplantations using left lateral segment grafts were performed at Tianjin First Central Hospital. The grafts from 162 (25.7%) donors have 2 hepatic vein openings. A total number of 21 transplantations using left lateral segment grafts with 2 widely spaced hepatic vein openings were performed. In group 1, the unification venoplasty technique with interposition vein graft was used at the back table for the reconstruction of hepatic vein from grafts. In group 2, dual hepatic vein reconstructions were performed, in which venoplasty of recipients' left hepatic vein, middle hepatic vein, and inferior vena cava was performed to create a large orifice for anastomosis with segment Ⅱ hepatic vein from the graft. Segment III hepatic vein from the graft was anastomosed with the recipient's right hepatic vein. The incidence, treatment, and outcomes of hepatic venous outflow obstruction were compared between the 2 groups. RESULTS: The median follow-up time was 12.8 months. There was no significant difference in the incidence of hepatic venous outflow obstruction between the 2 groups. CONCLUSION: Dual hepatic vein reconstruction is an alternate surgical option for grafts with 2 widely spaced hepatic veins, and it is associated with ideal graft recovery and vascular condition. However, long-term follow-up is still needed to verify the efficacy and safety of this approach.

The Integrated "Multiomics" Landscape at Peak Injury and Resolution From Alcohol-Associated Liver Disease.

Alcohol-associated liver disease (ALD) is a significant clinical problem for which the most effective therapy is alcohol abstinence. The two aims of this study were, first, to identify the liver transcriptome, fecal microbiome, and portal serum metabolome at peak injury and during early and late resolution from ALD; and second, to integrate their interactions and understand better the pathogenesis of ALD. To provoke alcohol-induced liver injury, female and male wild-type mice were fed the control or ethanol Lieber-DeCarli diets for 6 weeks. To study early and late resolution, alcohol was withdrawn from the diet and mice were sacrificed after 3 and 14 days, respectively. At peak injury, there was increased signal transducer and activator of transcription (Stat3), Rho-GTPases, Tec kinase and glycoprotein VI (Gp6), and decreased peroxisome proliferator-activated receptor signaling. During resolution from ALD, there was up-regulation of vitamin D receptor/retinoid X receptor, toll-like receptor, p38 and Stat3, and down-regulation of liver X receptor signaling. Females showed significant changes in catabolic pathways, whereas males increased cellular stress, injury, and immune-response pathways that decreased during resolution. The bacterial genus Alistipes and the metabolite dipeptide glycyl-L-leucine increased at peak but decreased during resolution from ALD in both genders. Hepatic induction of mitogen-activated protein kinase (Map3k1) correlated with changes in the microbiome and metabolome at peak but was restored during ALD resolution. Inhibition of MAP3K1 protected from ALD in mice. Conclusion: Alcohol abstinence restores the liver transcriptome, fecal microbiome, and portal serum metabolome in a gender-specific manner. Integration of multiomics data identified Map3k1 as a key gene driving pathogenesis and resolution from ALD.