m 6 A-mediated gluconeogenic enzyme PCK1 upregulation protects against hepatic ischemia-reperfusion injury.

BACKGROUND AND AIMS: Ischemia-reperfusion (I/R) injury frequently occurs during liver surgery, representing a major reason for liver failure and graft dysfunction after operation. The metabolic shift from oxidative phosphorylation to glycolysis during ischemia increased glucose consumption and accelerated lactate production. We speculate that donor livers will initiate gluconeogenesis, the reverse process of glycolysis in theory, to convert noncarbohydrate carbon substrates (including lactate) to glucose to reduce the loss of hepatocellular energy and foster glycogen storage for use in the early postoperative period, thus improving post-transplant graft function. APPROACH AND RESULTS: By analyzing human liver specimens before and after hepatic I/R injury, we found that the rate-limiting enzyme of gluconeogenesis, PCK1, was significantly induced during liver I/R injury. Mouse models with liver I/R operation and hepatocytes treated with hypoxia/reoxygenation confirmed upregulation of PCK1 during I/R stimulation. Notably, high PCK1 level in human post-I/R liver specimens was closely correlated with better outcomes of liver transplantation. However, blocking gluconeogenesis with PCK1 inhibitor aggravated hepatic I/R injury by decreasing glucose level and deepening lactate accumulation, while overexpressing PCK1 did the opposite. Further mechanistic study showed that methyltransferase 3-mediated RNA N6-methyladinosine modification contributes to PCK1 upregulation during hepatic I/R injury, and hepatic-specific knockout of methyltransferase 3 deteriorates liver I/R injury through reducing the N6-methyladinosine deposition on PCK1 transcript and decreasing PCK1 mRNA export and expression level. CONCLUSIONS: Our study found that activation of the methyltransferase 3/N6-methyladinosine-PCK1-gluconeogenesis axis is required to protect against hepatic I/R injury, providing potential intervention approaches for alleviating hepatic I/R injury during liver surgery.

The triglyceride-glucose index: a novel predictor of stroke and all-cause mortality in liver transplantation recipients.

BACKGROUND: The triglyceride-glucose (TyG) index, identified as a reliable indicator of insulin resistance (IR), was reported to be associated with stroke recurrence and morbidity in the general population and critically ill patients. However, the relationship in liver transplantation (LT) recipients remains unknown. This study aimed to investigate the correlation between the TyG index and post-LT stroke along with all-cause mortality and further assess the influence of IR on the LT recipients' prognosis. METHODS: The retrospective cohort study enrolled 959 patients who underwent LT at a university-based medical centre between January 2015 and January 2021. The participants were divided into three groups according to their TyG index tertiles. The primary outcome was post-LT stroke. Multivariate logistic regression, COX proportional hazards regression, and restricted cubic spline RCS were used to examine the association between the TyG index and outcomes in LT recipients. RESULTS: With a median TyG index of 8.23 (7.78-8.72), 780 (87.18% males) patients were eventually included. The incidence of post-LT stroke was 5.38%, and the in-hospital, 1-year, and 3-year mortality rates were 5.54%, 13.21%, and 15.77%, respectively. Multivariate regression analysis showed an independent association between the TyG index and an increased risk of post-LT stroke [adjusted odds ratio (aOR), 3.398 (95% confidence interval [CI]: 1.371-8.426) P = 0. 008], in-hospital mortality [adjusted hazard ratio (aHR), 2.326 (95% CI: 1.089-4.931) P = 0.025], 1-year mortality [aHR, 1.668 (95% CI: 1.024-2.717) P = 0.039], and 3-year mortality [aHR, 1.837 (95% CI: 1.445-2.950) P = 0.012]. Additional RCS analysis also suggested a linear increase in the risk of postoperative stroke with elevated TyG index (P for nonlinearity = 0.480). CONCLUSIONS: The TyG index may be a valuable and reliable indicator for assessing stroke risk and all-cause mortality in patients undergoing LT, suggesting its potential relevance in improving risk stratification during the peri-LT period.

Functional analysis of hepatic long non-coding ribonucleic acids during liver transplantation in humans.

BACKGROUND: The potential function of long non-coding RNAs (lncRNAs) in human hepatic ischemia-reperfusion injury (HIRI) remains to be clarified. METHODS: Clinical samples of transplanted liver tissues from 26 patients undergoing liver transplantation (LT) and normal liver tissues from seven patients undergoing hepatic hemangiomactomy (Con) were collected. Typical samples were subjected to whole transcriptome sequencing (RNA-seq). Differentially expressed genes between groups were identified by DEGseq and were analyzed by enrichment analysis including Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis. Transcription of five lncRNAs including NONHSAG039942, NONHSAG071405, NONHSAG027516, LXLOC_058190, and LXLOC_024376 that presented significant difference in RNA-sequencing were validated by a quantitative real-time PCR (qRT-PCR), for which the subcellular localization and the binding ability to known human RNA-binding proteins (RBPs) were respectively predicted by LncLocator and catRAPID genomics v2.1. RESULTS: We identified 2917 lncRNAs and 2811 mRNAs that were differentially expressed (p < 0.05 and log2 fold change > 1 or < -1) between groups (LT vs. Con). NONHSAG039942, NONHSAG071405, LXLOC_058190, and LXLOC_024376 were validated by qRT-PCR to be significantly increased in the LT group, and were all predicted to be localized in cytoplasm or cytosol. NONHSAG039942, NONHSAG071405, and LXLOC_058190 held an RBP interaction propensity score of 98.07%, 76.95%, and 152.99%, respectively, with heterogeneous-nuclear ribonucleoprotein U (HNRNPU). Pathways significantly activated in transplant livers that involved HNRNPU as a core enrichment gene included hypoxia, ACE2 expression, apoptosis, spliceosome formation, etc. CONCLUSIONS: NONHSAG039942, NONHSAG071405, and LXLOC_058190 were significantly increased in transplant livers after reperfusion and their role in HIRI may be associated with HNRNPU, a core protein that participates in hypoxia and chromatin accessibility.

The m6A methyltransferase Mettl3 deficiency attenuates hepatic stellate cell activation and liver fibrosis.

Activation of hepatic stellate cells (HSCs) is a central driver of liver fibrosis. Previous investigations have identified various altered epigenetic landscapes during the cellular progression of HSC activation. N6-methyladenosine (m6A) is the most abundant internal RNA modification in eukaryotic cells and is dynamically regulated under various physiological and pathophysiological conditions. However, the functional role of Mettl3-mediated m6A in liver fibrosis remains elusive. Here, we found that the HSC-specific knockout of m6A methyltransferase Mettl3 suppressed HSC activation and significantly alleviated liver fibrosis. Multi-omics analysis of HSCs showed that Mettl3 depletion reduced m6A deposition on mRNA transcripts of Lats2 (a central player of the Hippo/YAP signaling pathway) and slowed down their degradation. Elevated Lats2 increased phosphorylation of the downstream transcription factor YAP, suppressed YAP nuclear translocation, and decreased pro-fibrotic gene expression. Overexpressing YAP mutant resistant to phosphorylation by Lats2 partially rescued the activation and pro-fibrotic gene expression of Mettl3-deficient HSCs. Our study revealed that disruption of Mettl3 in HSCs mitigated liver fibrosis by controlling the Hippo/YAP signaling pathway, providing potential therapeutic strategies to alleviate liver fibrosis by targeting epitranscriptomic machinery.

An explainable supervised machine learning predictor of acute kidney injury after adult deceased donor liver transplantation.

BACKGROUND: Early prediction of acute kidney injury (AKI) after liver transplantation (LT) facilitates timely recognition and intervention. We aimed to build a risk predictor of post-LT AKI via supervised machine learning and visualize the mechanism driving within to assist clinical decision-making. METHODS: Data of 894 cases that underwent liver transplantation from January 2015 to September 2019 were collected, covering demographics, donor characteristics, etiology, peri-operative laboratory results, co-morbidities and medications. The primary outcome was new-onset AKI after LT according to Kidney Disease Improving Global Outcomes guidelines. Predicting performance of five classifiers including logistic regression, support vector machine, random forest, gradient boosting machine (GBM) and adaptive boosting were respectively evaluated by the area under the receiver-operating characteristic curve (AUC), accuracy, F1-score, sensitivity and specificity. Model with the best performance was validated in an independent dataset involving 195 adult LT cases from October 2019 to March 2021. SHapley Additive exPlanations (SHAP) method was applied to evaluate feature importance and explain the predictions made by ML algorithms. RESULTS: 430 AKI cases (55.1%) were diagnosed out of 780 included cases. The GBM model achieved the highest AUC (0.76, CI 0.70 to 0.82), F1-score (0.73, CI 0.66 to 0.79) and sensitivity (0.74, CI 0.66 to 0.8) in the internal validation set, and a comparable AUC (0.75, CI 0.67 to 0.81) in the external validation set. High preoperative indirect bilirubin, low intraoperative urine output, long anesthesia time, low preoperative platelets, and graft steatosis graded NASH CRN 1 and above were revealed by SHAP method the top 5 important variables contributing to the diagnosis of post-LT AKI made by GBM model. CONCLUSIONS: Our GBM-based predictor of post-LT AKI provides a highly interoperable tool across institutions to assist decision-making after LT.

Ultrasound-guided transmuscular quadratus lumborum block reduced postoperative opioids consumptions in patients after laparoscopic hepatectomy: a three-arm randomized controlled trial.

BACKGROUND: To investigate whether transmuscular quadratus lumborum block (TQLB) combined with oxycodone-based patient-controlled intravenous analgesia (PCIA) compared with sufentanil-based patient-controlled intravenous analgesia could reduce postoperative pain and opioid consumption in patients undergoing laparoscopic hepatectomy. METHODS: Eighty patients undergoing laparoscopic hepatectomy surgery were randomly divided into Group S (Sufentanil for PCIA group), Group O (Oxycodone for PCIA group) and Group QO (transmuscular quadratus lumborum block + oxycodone for PCIA group). Primary outcome was Numerical Rating Scale (NRS) pain score when coughing at 6th hour after the operation. We summarized opioid consumption and recorded complications, opioid drug adverse reaction and analgesia satisfaction. RESULTS: NRS pain scores were significantly lower in Group QO while patients coughing at 6th hour after the operation compared with Group S and Group O (median (interquartile range [IQR]):Group S vs. Group O vs. Group QO 4.0 [3.0, 5.0] vs. 4.0[3.0,5.0]vs.3.0 [2.0, 3.0], p < 0.05). Within 24 h after surgery, the bolus times of PCIA (patient controlled intravenous analgesia) in the QO group was reduced which was compared with the Group S and Group O (median (interquartile range [IQR]):Group S vs. Group O vs. Group QO 13.0 [10.3, 19.5] vs. 11.5 [7.8, 18.3]vs.6.5[3.5,12.0], p < 0.05). The proportion of patients in the three groups who required additional analgesia was ranked as Group QO < Group O < Group S(p < 0.05). The analgesic satisfaction of patients in Group QO was higher than the Group S (p = 0.001) and Group O (p = 0.012). CONCLUSIONS: TQLB combined with oxycodone-based PCIA provided satisfactory postoperative analgesia and reduced oxycodone consumption in patients following laparoscopic hepatectomy. TRIAL REGISTRATION: ChiCTR1900028467 (22/12/2019).

Propofol post-conditioning alleviates hepatic ischaemia reperfusion injury via BRG1-mediated Nrf2/HO-1 transcriptional activation in human and mice.

To explore the effects of propofol post-conditioning (PPC) on hepatic ischaemia/reperfusion injury (HIRI) and the potential mechanisms that might be involved in the interaction of Brahma-related gene1(BRG1) and Nuclear-related factor 2(Nrf2). Patients were randomized into PPC(n = 16) and non-PPC(NPC)( n = 21) groups. Propofol(2 mg/kg) was infused within 10 min. of the onset of liver reperfusion during liver transplantation in the PPC group. Liver function tests, as well as Brg1, Nrf2, Heme oxygenase-1(HO-1) and NADPH:quinone oxidoreductase1(NQO1) expression levels were evaluated. CMV-Brg1 mice were designed to investigate the role of Brg1 overexpression during HIRI. Brg1 and Nrf2 siRNA were used to examine the relationship between Brg1 and Nrf2/HO-1 pathways in propofol-mediated effects in a human hepatocyte(L02) hypoxia/reoxygenation(H/R) model. In patients, PPC attenuated both donor liver pathological and function injury, and reducing oxidative stress markers, compared to the NPC group, 24 hrs after surgery. PPC increased liver Brg1, Nrf2, HO-1 and NQO1 expression. In mice, PPC reduced HIRI by decreasing liver oxidative stress and activating Nrf2/HO-1 pathway, accompanied by up-regulation of BRG1 expression. BRG1 overexpression activated Nrf2/HO-1 transcription in CMV-BRG1 mice during HIRI. In vitro, PPC significantly elevated expression of Nrf2, HO-1 and NQO1, resulting in a reduction of cell DCFH-DA and 8-isoprostane levels and decreased lactate dehydrogenase levels, leading to an overall increase in cell viability. Moreover, the protective effects of propofol were partially abrogated in Nrf2-knock-down or BRG1-knock-down hepatocytes. Nrf2-knock-down drastically reduced protein expression of HO-1 and NQO1, while Brg1-knock-down decreased HO-1 expression. Propofol post-conditioning alleviates HIRI through BRG1-mediated Nrf2/HO-1 transcriptional activation.

Dexmedetomidine Protects Rat Liver against Ischemia-Reperfusion Injury Partly by the α2A-Adrenoceptor Subtype and the Mechanism Is Associated with the TLR4/NF-κB Pathway.

Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling plays a dominant role in the pathogenesis of liver ischemia-reperfusion (IR) injury. Dexmedetomidine (Dex) protects the liver against IR injury via α2-adrenoceptor activation, but the contribution of TLR4 signaling remains unknown. The authors aimed to examine whether pretreatment with Dex produces hepatic protection and investigate the influence of Dex on TLR4/NF-κB signaling. Dex was given via intraperitoneal injection 30 min prior to orthotopic autologous liver transplantation (OALT) in rats, and three α2-adrenoceptor antagonists including atipamezole (a nonselective α2 receptor blocker), ARC-239 (a specific α2B/C blocker) and BRL-44408 (a specific α2A blocker) were injected intraperitoneally 10 min before Dex administration. Histopathologic evaluation of the liver and the measurement of serum alanine aminotransferase activity, TLR4/NF-κB expression in the liver, and pro-inflammatory factors (serum tumor necrosis factor-α, interleukin-1ß and hepatic myeloperoxidase) concentrations were performed 8 h after OALT. Dex ameliorated liver injury after OALT probably by suppressing the TLR4/NF-κB pathway and decreasing inflammatory mediator levels. The protective effects of Dex were reversed by atipamezole and BRL-44408, but not by ARC-239, suggesting that these effects were mediated in part by the α2A subtype. In conclusion, Dex attenuates liver injury partly via the α2A-adrenoceptor subtype, and the mechanism is due to the suppression of the TLR4/NF-κB pathway.

Propofol alleviates liver oxidative stress via activating Nrf2 pathway.

BACKGROUND: Nuclear factor-E2-related factor 2 (Nrf2)-mediated antioxidant response is the main protective system of graft-liver against ischemia-reperfusion injury after liver transplantation. Propofol is considered to confer protective effects on different organs; thus, we explored the possibility that whether propofol could attenuate graft-liver injury in a rat autologous orthotopic liver transplantation (AOLT) model and mechanisms were associated with activation of Nrf2 pathway. METHODS: Sprague-Dawley rats were randomly divided into four groups: sham-operated group, saline-treated AOLT group, low-dose propofol intervention group, and high-dose propofol intervention group. Liver injury was determined, and concentration of hydroxyl free radical (•OH), superoxide anion (O2(•-)), and malondialdehyde in the liver tissue were detected. The expression of Keap1, Nrf2, HO-1, and NQO1 were explored by Western blotting, and also the change of Nrf2 and keap1 was assessed by immunofluorescence. RESULTS: Compared with sham group, pathologic damage of graft-livers was in a time-dependent manner, accompanied with the increased level of oxidative stress in the AOLT group, and nuclear Nrf2 expression and its downstream antioxidant enzyme, HO-1 and NQO1, were also increased in this group. However, in propofol pretreatment groups especially in the high-dose group, the pathologic score was significantly decreased, accompanied with a lower level of •OH, O2(•-), and malondialdehyde than that of the AOLT group. The change of oxidative stress might be related to the Nrf2 pathway, evidenced as the elevation of protein expression level of NQO1, HO-1, and nuclear Nrf2. CONCLUSIONS: Protective effects of propofol against liver transplantation-induced graft-liver injury may be related with Keap1-Nrf2 signal pathway activation.

Downregulation of Lung Toll-Like Receptor 4 Could Effectively Attenuate Liver Transplantation-Induced Pulmonary Damage at the Early Stage of Reperfusion.

Acute lung injury (ALI) is a severe complication of orthotopic liver transplantation (OLT) with unclear underline mechanism. Toll-like receptor 4 (TLR4) has been identified as a key receptor mediating inflammation. We hypothesized that TLR4-mediated pulmonary inflammation may contribute to development of ALI during OLT. Patients with or without ALI were observed for serum cytokines and expression of TLR4 on peripheral blood polymorphonuclear leukocytes (PMNs). Next, rats which underwent orthotopic autologous liver transplantation (OALT) were divided into sham and model groups. Pulmonary function and the level of TLR4 expression and cytokines were analyzed. Furthermore, the role of TLR4 in OALT-mediated ALI was assessed in rats treated with TLR4-siRNA before OALT. The PMNs TLR4 expression and the serum TNF-α and IL-ß level were higher in patients with ALI than those with non-ALI. Interestingly, lung TLR4 expression was significantly increased after 8 hours of OALT with increased levels of TNF-α and IL-ß, which lead to lung pathological damage and an increase of lung myeloperoxidase content. Moreover, knockdown of TLR4 reduced lung cytokines release and reversed the above pathologic changes after OALT and finally improved rats' survival rate. In conclusion, TLR4 overexpression, potentially by stimulating proinflammatory cytokine overproduction, contributes to the development of ALI after OLT.

Using inflammatory and oxidative biomarkers in urine to predict early acute kidney injury in patients undergoing liver transplantation.

OBJECTIVE: We examined the value of inflammatory and oxidative biomarkers in predicting acute kidney injury (AKI) following orthotopic liver transplantation (OLT). METHODS: Urinary excretion of tumour necrosis factor-α (TNF-α), interleukin-8 (IL-8), interleukin-10 (IL-10), superoxide dismutase (SOD), malondialdehyde (MDA), 6-keto prostaglandin F1α (6-keto-PGF1α), hydrogen peroxide (H2O2), and 8-keto prostaglandin F2α (8-iso-PGF2α), serum creatinine (SCr), blood urea nitrogen (BUN), urinary N-acetyl-beta-D-glucosaminidase (NAG), ß2-microglobulin (ß2-MG) and γ-glutamyl-transferase (γ-GT), were measured before surgery (baseline), at 2 h after graft reperfusion and 24 h after OLT in 28 liver transplantation patients. RESULTS: The levels of TNF-α, IL-8, IL-10, SOD, MDA, 6-keto-PGF1α, H2O2 and 8-iso-PGF2α in urine were all significantly higher in patients who had AKI than in those who did not at 2 h after graft reperfusion and 24 h after OLT (p < 0.01).

Postoperative SIRS after thermal ablation of HCC: Risk factors and short-term prognosis.

Background: We aimed to explore the potential risk factors and short-term prognosis for SIRS after thermal ablation of hepatocellular carcinoma (HCC). Methods: Data from patients with HCC who underwent thermal ablation in the Third Affiliated Hospital of Sun Yat-sen University between January 2015 and August 2021 were retrieved from the perioperative database. Pre-, intra- and postoperative data between SIRS group and non-SIRS group were compared and multivariate logistic regression analysis was performed to identify the risk factors for SIRS after thermal ablation. Results: A total of 1491 patients were enrolled and 234 (15.7 %) patients developed SIRS after thermal ablation. Compared with those without SIRS, patients with SIRS had a longer hospital stay, higher hospitalization costs and higher risk of more severe postoperative complications. In the multivariate logistic regression analysis, current smoking (OR 1.58, 95 %CI 1.09-2.29), decreased HCT (OR 1.51,95 %CI 1.11-2.04), NEUT < 1.5 × 109/L(OR 1.74, 95 %CI 1.14-2.65), NEUT% < 0.5 or > 0.7 (OR 1.36, 95 %CI 1.01-1.83) and PT > 16.3s (OR 2.42, 95 %CI 1.57-3.74) were significantly associated with postoperative SIRS. Conclusions: Current smoking, decreased HCT, neutropenia, abnormal percentage of neutrophils and prolonged PT are the independent risk factors for SIRS after thermal ablation of HCC, which worsens outcomes of patients. This study can help identify high-risk population and guide appropriate care so as to reduce the incidence of postoperative SIRS.

[Effects of cromolyn sodium on intestinal ischemia-reperfusion injury by inhibiting PAR-2 expression in rats].

OBJECTIVE: To explore the effects of cromolyn sodium (CS) on intestinal ischemia-reperfusion (IIR) and its relationship with mast cell activation and protease-activated receptor 2 (PAR-2) expression. METHODS: A total of 32 SD rats were randomly divided into 4 groups: sham-operated (S), intestinal ischemia reperfusion (IIR), CS (a mast cell stabilizer, CS, 25 mg/kg) and compound 48/80 (a mast cell degranulation, CP, 0.75 mg/kg) (n = 8 each). IIR was induced by clamping superior mesenteric artery for 75 min followed by reperfusion for 3 hours. The above agents were intravenously administrated at 5 min pre-reperfusion. Rats were then sacrificed and intestinal issues harvested for histological examinations. The tryptase expression and mast cell count were analyzed by immunohistochemistry. PAR-2 was analyzed by Western blot. RESULTS: The Chiu's score (0.75 ± 0.21), mast cell count (10 ± 3), tryptase expression (125 ± 15) and PAR-2 expression (109 ± 10) of group S were the least while those of group CP the most (all P < 0.05). The Chiu's score (2.14 ± 0.64), mast cell count (15 ± 4), tryptase expression (138 ± 17) and PAR-2 expression (124 ± 12) of group CS were less than those of groups IIR and CP (all P < 0.05). CONCLUSION: Cromolyn sodium may reduce IIR injury by stabilizing mast cell membrane and inhibiting the expressions of tryptase and PAR-2.

The frequency and risk factors of major complications after thermal ablation of liver tumours in 2,084 ablation sessions.

Background: To assess the frequency of major complications after thermal ablation of liver tumours and to determine risk factors for adverse events. Methods: A retrospective study was conducted between January 2015 and January 2021. A total of 2,084 thermal ablation sessions in 1,592 patients with primary and metastatic liver tumours were evaluated. The frequency of major complications was evaluated according to the Society of Interventional Radiology Standards, and putative predictors of adverse events were analysed using simple and multivariate logistic regression. Results: Thermal ablation-related mortality was 0.1% (2/2,084), with an overall major complication rate of 5.6% (117/2,084). The most frequent major complication was symptomatic pleural effusion (2.9%, 60/2,084). Multivariate logistic regression analysis revealed that a total maximum diameter of lesions >3 cm, microwave ablation (MWA) and MWA combined with radiofrequency ablation, intrahepatic cholangiocarcinoma and postoperative systemic inflammatory response syndrome were independent prognostic factors for major complications. Conclusions: Thermal ablation of liver tumours is a safe procedure with an acceptable incidence of major complications. The risk factors identified in this study will help to stratify high-risk patients.

Inhibition of the NADPH Oxidase Pathway Reduces Ferroptosis during Septic Renal Injury in Diabetic Mice.

Background: Obesity and type 2 diabetes mellitus (DM) contribute to a higher mortality rate in patients with septic acute kidney injury (AKI) during sepsis. Reactive oxygen species (ROS) is the major injury factor for sepsis. This study was aimed at exploring the potential therapeutic drug for septic AKI targeting on ROS. Methods: A murine septic AKI model was established in both wild-type and high-fat diet-fed (HFD) mice. NADPH oxidase inhibitor Vas2870 was used in vivo to explore the role of NADPH oxidase in ROS release in septic AKI in diabetic mice. Ferrostatin-1 was administered to investigate the role of ferroptosis in ROS accumulation during NADPH oxidase activating in septic AKI in diabetic mice. Results: Compared to chow diet-fed mice, HFD diabetic mice which were subjected to LPS exhibited aggravated renal function (blood urea nitrogen, creatinine clearance, and serum cystatin C) and oxidative stress (malondialdehyde, 4-HNE, ROS, 8-OHdG, and NADPH oxidase), thus resulting in a higher mortality rate. Septic renal injury was significantly attenuated by the ferroptosis inhibitor Fer-1 in HFD-challenged mice. Furthermore, ferroptosis accumulation and related protein expression (ASCL4, FTH1, and GPX4) were altered by LPS stimulation in HFD-challenged mice and suppressed by NADPH oxidase inhibition via Vas2870 in vivo. In summary, NADPH inhibition restored septic renal function from injury by suppressing ferroptosis accumulation in HFD-challenged mice. Conclusion: These results suggest that targeting NADPH-mediated ROS release and ferroptosis accumulation is a novel therapeutic strategy to protect the kidney from septic injury in patients with obesity and type 2 DM.

Deletion of Mettl3 at the Pro-B Stage Marginally Affects B Cell Development and Profibrogenic Activity of B Cells in Liver Fibrosis.

N6-methyladenosine (m6A) modification plays a pivotal role in cell fate determination. Previous studies show that eliminating m6A using Mb1-Cre dramatically impairs B cell development. However, whether disturbing m6A modification at later stages affects B cell development and function remains elusive. Here, we deleted m6A methyltransferase Mettl3 from the pro-B stage on using Cd19-Cre (Mettl3 cKO) and found that the frequency of total B cells in peripheral blood, peritoneal cavity, and liver is comparable between Mettl3 cKO mice and wild-type (WT) littermates, while the percentage of whole splenic B cells slightly increases in Mettl3 cKO individuals. The proportion of pre-pro-B, pro-B, pre-B, immature, and mature B cells in the bone marrow were minimally affected. Loss of Mettl3 resulted in increased apoptosis but barely affected B cells' proliferation and IgG production upon LPS, CD40L, anti-IgM, or TNF-α stimulation. Different stimuli had different effects on B cell activation. In addition, B cell-specific Mettl3 knockout had no influence on the pro-fibrogenic activity of B cells in liver fibrosis, evidenced by comparable fibrosis in carbon tetrachloride- (CCl4-) treated Mettl3 cKO mice and WT controls. In summary, our study demonstrated that deletion of Mettl3 from the pro-B stage on has minimal effects on B cell development and function, as well as profibrogenic activity of B cells in liver fibrosis, revealing a stage-specific dependence on Mettl3-mediated m6A of B cell development.

Sevoflurane preconditioning activates HGF/Met-mediated autophagy to attenuate hepatic ischemia-reperfusion injury in mice.

Sevoflurane (SEV) preconditioning plays a protective effect against liver ischemia reperfusion (IR) injury, while the role of autophagy in SEV-mediated hepatoprotection and the precise mechanism is unclear. In the current study, mice were pretreated with SEV or autophagy inhibitor before liver IR injury. In vitro, primary rat hepatocytes were pretreated with SEV and then exposed to hypoxia/reoxygenation (H/R). Liver function was measured by biochemical and histopathological examinations, and markers associated with inflammation, oxidation, apoptosis and autophagy were subsequently measured. We found that SEV preconditioning dramatically reduced hepatic damage, alleviated cell inflammatory response, oxidative stress and apoptosis in mice suffering hepatic IR injury, whereas these protective effects were abolished by the autophagy inhibitor 3-MA. In addition, pretreatment with SEV markedly activated HGF/Met signaling pathway regulation. Besides, pretreatment with an hepatocyte growth factor (HGF) inhibitor or knocking down HGF expression significantly downregulated phosphorylated met (p-met) and autophagy levels, and abolished the protective effects of SEV against hepatic IR or hepatocyte H/R injury. Conversely, HGF overexpression efficiently increased the p-met and autophagy levels and strengthened the protective effects of SEV. These results indicated that sevoflurane preconditioning ameliorates hepatic IR injury by activating HGF/Met-mediated autophagy.

N6-methyladenosine (m6A) methylation in ischemia-reperfusion injury.

Ischemia-reperfusion (I/R) injury is common during surgery and often results in organ dysfunction. The mechanisms of I/R injury are complex, diverse, and not well understood. RNA methylation is a novel epigenetic modification that is involved in the regulation of various biological processes, such as immunity, response to DNA damage, tumorigenesis, metastasis, stem cell renewal, fat differentiation, circadian rhythms, cell development and differentiation, and cell division. Research on RNA modifications, specifically N6-methyladenosine (m6A), have confirmed that they are involved in the regulation of organ I/R injury. In this review, we summarized current understanding of the regulatory roles and significance of m6A RNA methylation in I/R injury in different organs.

High-fat diet increased NADPH-oxidase-related oxidative stress and aggravated LPS-induced intestine injury.

AIMS: Lipopolysaccharide (LPS)-induced intestinal injury is a common clinical feature of sepsis. Aggravated inflammation and higher sensitivity to infection are associated with high-fat diet (HFD) in patients with type 2 diabetes and/or obesity. However, the mechanism by which HFD exacerbates LPS-induced intestinal injury has not been elucidated. This study aims to examine the effects of HFD on intestinal injury induced by LPS and the underlying mechanism. MAIN METHODS: Mice were fed with HFD or regular chow for 12weeks and were then challenged with LPS. Vas2870 was administered to mice that received HFD before the initiation of the diet. The levels of tight junction protein expression, oxidative stress, organ injury, and nicotinamide adenine dinucleotide phosphate (NADPH)-associated proteins were assessed periodically. KEY FINDINGS: LPS treatment resulted in severe intestinal pathological injury and increased oxidative stress, evidenced by significantly increased serum diamine oxidase, reactive oxygen species, malondialdehyde, and intestinal fatty acid binding protein contents. Additionally, a decrease in tight junction protein expression was observed, indicating a loss of tight junction integrity. LPS treatment induced the expression of Nox2 and Nox4. All the effects were more severe in HFD mice. Treatment with vas2870 conferred protection against LPS-induced intestinal injury in HFD-fed mice, partially reduced oxidative stress, and rescued the expression of tight junction proteins. CONCLUSION: HFD aggravated LPS-induced intestine injury through exacerbating intestinal Nox-related oxidative stress, which led to a loss of the integrity of tight junctions and consequently increased intestinal permeability.

Determining whether dexmedetomidine provides a reno-protective effect in patients receiving laparoscopic radical prostatectomy: a pilot study.

PURPOSE: This study aims to determine whether perioperative treatment with dexmedetomidine (DEX) during laparoscopic radical prostatectomy (LRP) can provide a reno-protective effect. METHODS: This pilot study enrolled 89 patients between 60 and 79 years old, who underwent LRP. These patients were randomly allocated into two groups: group D (n = 44) and group C (n = 45). For patients in group D, 1 µg/kg of DEX was intravenously administered within 10 min, followed by 0.5 µg/kg/h of DEX infusion during the operation. This was stopped at 30 min before the end of surgery. For patients in group C, saline was administered at the same doses. The primary outcome was the incidence of acute kidney injury (AKI), and secondary outcomes included other postoperative variables. RESULTS: The incidence of AKI in group D and C was 4.5% and 13.3%, respectively (P > 0.05). Compared with group C, patients in group D had significantly lower urea nitrogen levels at 6 h after surgery, lower creatinine levels at 6 and 48 h after surgery, and significantly lower CysC levels at 48 h after surgery. A significant decrease in VAS scores for pain and postoperative nausea and vomiting (PONV) at the second and third day after surgery was observed in patients in group D when compared to patients in group C. CONCLUSION: Intraoperative DEX does not reduce the incidence of AKI, but provides a potential reno-protective effect, and alleviates postoperative pain and PONV in patients undergoing LRP.