Hepatic Ischemia-reperfusion Research Articles

PDGFRα/Sca-1 Sorted Mesenchymal Stromal Cells Reduce Liver Injury in Murine Models of Hepatic Ischemia-Reperfusion Injury.

Liver transplantation is an effective therapy, but increasing demand for donor organs has led to the use of marginal donor organs with increased complication rates. Mesenchymal stromal cells (MSC) pleiotropically modulate aberrant immune-mediated responses and represent a potential therapy to target the inflammation seen post-transplant with marginal donor livers. To avoid the confounding effects of xenotransplantation seen in studies with human MSC, a PDGFRα/Sca-1 (PaS) sorted MSC population was used which was analogous to human MSC populations (LNGFR+Thy-1+VCAM-1Hi). PaS MSC are a well-described population that demonstrate MSC properties without evidence of clonal mutation during expansion. We demonstrate their anti-inflammatory properties herein through their suppression of T-lymphocyte proliferation in vitro and secretion of anti-inflammatory cytokines (IL-10 and OPG) after stimulation (P = .004 and P = .003). The MDR2-/- model of biliary injury and hepatic ischemia-reperfusion (HIR) injury models were used to replicate the non-anastomotic biliary complications seen following liver transplantation. Systemic MSC therapy in MDR2-/- mice led to reduced liver injury with an increase in restorative macrophages (5913 ± 333.9 vs 12 597 ± 665.8, P = .002, n = 7) and a change in lymphocyte ratios (3.55 ± 0.37 vs 2.59 ± 0.139, P = .023, n = 17), whereas subcutaneous administration of MSC showed no beneficial effect. MSC also reduced cell death in the HIR model assessed by Periodic acid-Schiff (PAS) staining (91.7% ± 2.8 vs 80.1% ± 4.6, P = .03). Systemically administered quantum dot-labeled MSC were tracked using single-cell resolution CryoViz imaging which demonstrated their sequestration in the lungs alongside retention/redistribution to injured liver tissue. MSC represent a potential novel therapy in marginal organ transplantation which warrants further study.

Protective effect of adipose-derived stromal cell-secretome attenuate autophagy induced by liver ischemia–reperfusion and partial hepatectomy

BackgroundThe therapeutic effects of adipose-derived mesenchymal stromal cells (ADSCs) may be mainly mediated by their paracrine effects. The ADSC-secretome can ameliorate hepatic ischemia–reperfusion injury (IRI). We explored the therapeutic effect of the ADSC-secretome from the perspective of excessive hepatocyte autophagy induced by hepatic IRI.MethodsWe established a miniature pig model of hepatic ischemia–reperfusion (I/R) and hepatectomy using a laparoscopic technique and transplanted ADSCs and the ADSC-secretome into the liver parenchyma immediately after surgery. Liver injury and hepatocyte autophagy were evaluated by histopathological examination and assessment of relevant cytokines and other factors.ResultsThe results showed that the ADSC-secretome alleviated the pathological changes of liver tissue and the microstructural damage of hepatocytes after IRI. Moreover, the expression levels of autophagy-related markers including Beclin-1, ATG5, ATG12, and LC3II/LC3I decreased, whereas those of p62 increased during phagophore expansion. Furthermore, the expression levels of markers related to the autophagy inhibition pathway phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR), including PI3K, Akt, and mTOR, increased.ConclusionThe ADSC-secretome attenuates hepatic I/R and hepatectomy-induced liver damage by inhibiting autophagy, which is possibly mediated by activation of the PI3K/Akt/mTOR signaling pathway. In addition, there was no significant difference between ADSCs and the ADSC-secretome in the regulation of hepatocyte autophagy. Therefore, ADSCs may improve the excessive autophagy-induced injury of hepatocytes in hepatic I/R and hepatectomy through paracrine effect. Our findings provide new insight into the therapeutic potential of cell-free products, which could replace cell therapy in liver diseases.

Polydatin ameliorates hepatic ischemia-reperfusion injury by modulating macrophage polarization

BackgroundPolydatin, a glucoside of resveratrol, has shown protective effects against various diseases. However, little is known about its effect on hepatic ischemia-reperfusion (I/R) injury. This study aimed to elucidate whether polydatin protects liver against I/R-induced injury and to explore the underlying mechanism. MethodsAfter gavage feeding polydatin once daily for a week, mice underwent a partial hepatic I/R procedure. Serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST), hematoxylin-eosin (H&E) and TdT-mediated dUTP nick-end labeling (TUNEL) staining were used to evaluate liver injury. The severity related to the inflammatory response and reactive oxygen species (ROS) production was also investigated. Furthermore, immunofluorescence and Western blotting were used to detect macrophage polarization and the NF-κB signaling pathway in macrophages. ResultsCompared with the I/R group, polydatin pretreatment significantly attenuated I/R-induced liver damage and apoptosis. The oxidative stress marker (dihydroethidium fluorescence, malondialdehyde, superoxide dismutase and glutathione peroxidase) and I/R related inflammatory cytokines (interleukin-1β, interleukin-10 and tumor necrosis factor-α) were significantly suppressed after polydatin treatment. In addition, the result of immunofluorescence indicated that polydatin reduced the polarization of macrophages toward M1 macrophages both in vivo and in vitro. Western blotting showed that polydatin inhibited the pro-inflammatory function of RAW264.7 via down-regulating the NF-κB signaling pathway. ConclusionsPolydatin protects the liver from I/R injury by remodeling macrophage polarization via NF-κB signaling.

Salidroside alleviates hepatic ischemia–reperfusion injury during liver transplant in rat through regulating TLR-4/NF-κB/NLRP3 inflammatory pathway

Salidroside has anti-inflammatory, antioxidant and hepatoprotective properties. However, its effect on hepatic ischemia–reperfusion injury (IRI), an unavoidable side effect associated with liver transplantation, remains undefined. Here, we aimed to determine whether salidroside alleviates hepatic IRI and elucidate its potential mechanisms. We used both in vivo and in vitro assays to assess the effect and mechanisms of salidroside on hepatic IRI. Hepatic IRI rat models were pretreated with salidroside (5, 10 or 20 mg/kg/day) for 7 days following liver transplantation while hypoxia/reoxygenation (H/R) model of RAW 264.7 macrophages were pretreated with salidroside (1, 10 or 50 μM). The effect of salidroside on hepatic IRI was assessed using hematoxylin–eosin staining, terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, qRT-PCR, immunosorbent assay and western blotting. Our in vivo assays showed that salidroside significantly reduced pathological liver damage, serum aminotransferase levels and serum levels of IL-1, IL-18 and TNF-α. Besides, salidroside reduced the expression of TLR-4/NF-κB/NLRP3 inflammatory pathway associated proteins (TLR-4, MyD88, p-IKKα, p-IKKβ, p-IKK, p-IκBα, p-P65, NLRP3, ASC, Cleaved caspase-1, IL-1β, IL-18, TNF-α and IL-6) in rats after liver transplantation. On the other hand, data from the in vitro analysis demonstrated that salidroside blocks expression of TLR-4/NF-κB/NLRP3 inflammatory pathway related proteins in the RAW264.7 cells treated with H/R. The salidroside-specific anti-inflammatory effects were partially inhibited by the TLR-4 agonist lipopolysaccharide. Taken together, our study showed that salidroside inhibits hepatic IRI following liver transplantation by modulating the TLR-4/NF-κB/NLRP3 inflammatory pathway.

Mild hypothermia ameliorates hepatic ischemia reperfusion injury by inducing RBM3 expression

Liver ischemia reperfusion injury (IRI) is a serious complication of certain liver surgeries, and it is difficult to prevent. As a potential drug-free treatment, mild hypothermia has been shown to promote positive outcomes in patients with IRI. However, the protective mechanism remains unclear. We established in vivo and in vitro models of hepatic ischemia reperfusion (IR) and mild hypothermia pretreatment. Hepatocytes were transfected with RNA-binding motif protein 3 (RBM3) overexpression plasmids, and IR was performed. Cell, culture medium, blood and tissue samples were collected to assess hepatic injury, oxidative stress, apoptosis and changes in RBM3 expression in the liver. Upregulation of RBM3 expression by mild hypothermia reduced the aminotransferase release, liver tissue injury and mitochondrial injury induced by liver IR. Hepatic IR-induced p38 and c-Jun N-terminal kinase (JNK) signaling pathway activation, oxidative stress injury and apoptosis could be greatly reversed by mild hypothermia. Overexpression of RBM3 mimicked the hepatoprotective effect of mild hypothermia. Mild hypothermia protects the liver from ischemia reperfusion-induced p38 and JNK signaling pathway activation, oxidative stress injury and apoptosis through the upregulation of RBM3 expression.

Luteolin Pretreatment Attenuates Hepatic Ischemia-Reperfusion Injury in Mice by Inhibiting Inflammation, Autophagy, and Apoptosis via the ERK/PPARα Pathway.

Hepatic ischemia-reperfusion (IR) injury is a clinically significant process that frequently occurs in liver transplantation, partial hepatectomy, and hemorrhagic shock. The aim of this study was to explore the effectiveness of luteolin in hepatic IR injury and the underlying mechanism. BALB/c mice were randomly divided into six groups, including normal controls (NC), luteolin (50 mg/kg), sham procedure, IR+25 mg/kg luteolin, and IR+50 mg/kg luteolin group. Serum and tissue samples were collected at 6 and 24 h after reperfusion to assay liver enzymes, inflammatory factors, expression of proteins associated with apoptosis and autophagy, and factors associated with the extracellular signal-regulated kinase/peroxisome proliferator-activated receptor alpha (ERK/PPARα) pathway. Luteolin preconditioning decreased hepatocyte injury caused by ischemia-reperfusion, downregulated inflammatory factors, and inhibited apoptosis and autophagy. Luteolin also inhibited ERK phosphorylation and activated PPARα.

Targeting p21-activated kinase 4 (PAK4) with pyrazolo[3,4-d]pyrimidine derivative SPA7012 attenuates hepatic ischaemia-reperfusion injury in mice

p21-Activated kinase 4 (PAK4), one of the serine/threonine kinases activated by Rho-family GTPases, has been widely studied as an oncogenic protein that is overexpressed in many types of cancers. In our recent study, PAK4 upregulation was observed in mice exhibiting hepatic ischaemia-reperfusion (I/R) and in liver transplantation patients. Liver I/R injury was also attenuated in Pak4 KO mice. Herein, we report a novel series of pyrazolo[3,4-d]pyrimidine derivatives of type I ½ PAK4 inhibitors. The most potent compound SPA7012 was evaluated to determine the pharmacological potential of PAK4 inhibitor in I/R injury in mice. Mice with I/R injury showed typical patterns of liver damage, as demonstrated by increases in serum levels of aminotransferases and proinflammatory cytokines, hepatocellular necrosis and apoptosis, and inflammatory cell infiltration, relative to sham mice. Conversely, intraperitoneal administration of SPA7012 dramatically attenuated biochemical and histopathologic changes. Mechanistically, stabilisation of nuclear factor-erythroid 2-related factor 2 (Nrf2), a master regulator of anti-oxidative response, was observed following SPA7012 treatment. SPA7012 treatment in primary hepatocytes also attenuated hypoxia-reoxygenation-induced apoptotic cell death and inflammation. Together, these results provide experimental evidence supporting the use of PAK4 inhibitors for alleviation of I/R-induced liver damage.

MCTR1 inhibits ferroptosis by promoting NRF2 expression to attenuate hepatic ischemia-reperfusion injury.

Hepatic ischemia-reperfusion injury (HIRI) can lead to poor prognosis in patients undergoing liver transplantation or extensive liver resection. Maresin conjugate in tissue regeneration 1 (MCTR1) exerts a protective effect in several inflammatory disease models, but its role in HIRI remains unknown. In this study, we examined the effect of MCTR1 on HIRI and its underlying mechanism. HIRI mice and oxygen-glucose deprivation/reperfusion (OGD/R) AML12 cell models were used to evaluate the effects of MCTR1 at different doses on HIRI. Histological changes, inflammatory mediators, and ferroptosis-associated markers including iron content, oxidative stress and antioxidant activity, cell death marker (LDH), and the expression of Nuclear factor erythroid-derived 2-like 2 (NRF2) were analyzed. The results showed that MCTR1 treatment significantly ameliorated liver tissue damage and AST/ALT levels in HIRI mice. It also ameliorated ferroptosis in both HIRI mice and OGD/R AML12 cells, including a decrease in iron content, serum LDH release levels, reactive oxygen species (ROS), MDA, IL-1β levels, and COX2 and transferrin receptor (TFRC) expression. In addition, it increased the levels of IL-10, the antioxidant stress markers SOD and GSH, and the expression of GPX4. With respect to the underlying mechanism, the expression of NRF2 in HIRI mice and OGD/R AML12 cells was significantly inhibited. MCTR1 treatment restored the inhibition of NRF2 expression caused by ischemia-reperfusion, and NRF2 inhibitors significantly inhibited nuclear aggregation of NRF2 promoted by MCTR1. In conclusion, the MCTR1 ameliorates ferroptosis-induced hepatic ischemia-reperfusion injury by promoting NRF2 expression and may represent a therapeutic strategy for treating HIRI.NEW & NOTEWORTHY MCTR1 exerts a protective effect in several inflammatory disease models, but its role in hepatic HIRI remains unknown. We confirm that the MCTR1 ameliorates ferroptosis-induced hepatic ischemia-reperfusion injury by promoting NRF2 expression. Our study illustrates the mechanism that MCTR1 protects from HIRI and identifies a therapeutic target for liver transplantation ischemia-reperfusion injury from the perspective of ferroptosis.

Effect of Edaravone on MicroRNA Expression in Exosomes after Hepatic Ischemia-reperfusion Injury.

Hepatic ischemia-reperfusion injury (HIRI) results in serious complications after liver resection and transplantation. Edaravone (ED) has a protective effect on IRI. This study was designed to evaluate whether ED could protect the liver of rats from HIRI injury and explored its exosomal miRNA-related mechanism. The sham group, hepatic ischemia/reperfusion (IR group), and hepatic ischemia/reperfusion + edaravone (ED group) models were established. We determined the protective effect of ED by measuring alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), superoxide dismutase (SOD); enzyme-linked immunosorbent assay for tumor necrosis factor- α (TNF-α) and interleukin-1β (IL-1β); hematoxylin-eosin staining and immunohistochemistry for histopathological changes. Exosomal miRNAs were subjected to second-generation sequencing to identify their differential expression. The results were analyzed using bioinformatics methods and validated using real-time quantitative polymerase chain reaction (RT-qPCR). HIRI rats showed higher levels of ALT, AST, oxidative stress, and inflammatory markers; ED attenuated these effects. The sequencing results showed 6 upregulated and 13 downregulated miRNAs in the IR vs. sham groups, 10 upregulated and 10 downregulated miRNAs in the ED vs. IR groups. PC-3p-190-42101 was screened as an overlapping differentially expressed miRNA, and RT-qPCR validation showed that its expression in HIRI rats was significantly decreased; ED prevented this downregulation. Moreover, the expression of PC-3P-190-42101 was significantly correlated with the level of inflammatory factors. These findings indicate that ED can regulate the level of inflammatory factors by affecting the expression of miRNA PC-3p-190-42101 in plasma exosomes to protect the liver from IRI.

ILC2s expanded by exogenous IL-33 regulate CD45+CD11b+F4/80high macrophage polarization to alleviate hepatic ischemia-reperfusion injury.

Hepatic ischemia-reperfusion injury (IRI) is an adverse consequence of hepatectomy or liver transplantation. Recently, immune mechanisms involved in hepatic IRI have attracted increased attention of investigators working in this area. In specific, group 2 innate lymphoid cells (ILC2s), have been strongly implicated in mediating type 2 inflammation. However, their immune mechanisms as involved with hepatic IRI remain unclear. Here, we reported that the population of ILC2s is increased with the development of hepatic IRI as shown in a mouse model in initial stage. Moreover, M2 type CD45+CD11b+F4/80high macrophages increased and reached maximal levels at 24 h followed by a significant elevation in IL-4 levels. We injected exogenous IL-33 into the tail vein of mice as a mean to stimulate ILC2s production. This stimulation of ILC2s resulted in a protective effect upon hepatic IRI along with an increase in M2 type CD45+CD11b+F4/80high macrophages. In contrast, depletion of ILC2s as achieved with use of an anti-CD90.2 antibody substantially abolished this protective effect of exogenous IL-33 and M2 type CD45+CD11b+F4/80high macrophage polarization in hepatic IRI. Therefore, this exogenous IL-33 induced potentiation of ILC2s appears to regulate the polarization of CD45+CD11b+F4/80high macrophages to alleviate IRI. Such findings provide the foundation for the development of new targets and strategies in the treatment of hepatic IRI.

Effect of intraoperative dexmedetomidine on hepatic ischemia-reperfusion injury in pediatric living-related liver transplantation: A propensity score matching analysis

BackgroundHepatic ischemia-reperfusion injury (HIRI) is largely unavoidable during liver transplantation (LT). Dexmedetomidine (DEX), an α2-adrenergic agonist, exerts a variety of organ-protective effects in pediatric populations. However, evidence remains relatively limited about its hepatoprotective effects in pediatric living-related LT.MethodsA total of 121 pediatric patients undergoing living-related LT from June 2015 to December 2018 in our hospital were enrolled. They were classified into DEX or non-DEX groups according to whether an infusion of DEX was initiated from incision to the end of surgery. Primary outcomes were postoperative liver graft function and the severity of HIRI. Multivariate logistic regression and propensity score matching (PSM) analyses were performed to identify any association.ResultsA 1:1 matching yielded 35 well-balanced pairs. Before matching, no significant difference was found in baseline characteristics between groups except for warm ischemia time, which was longer in the non-DEX group (44 [38–50] vs. 40 [37–44] min, p = 0.017). After matching, the postoperative peak lactic dehydrogenase levels decreased significantly in the DEX group than in the non-DEX group (622 [516–909] vs. 970 [648–1,490] IU/L, p = 0.002). Although there was no statistical significance, a tendency toward a decrease in moderate-to-extreme HIRI rate was noted in the DEX group compared to the non-DEX group (68.6% vs. 82.9%, p = 0.163). Patients in the DEX group also received a significantly larger dosage of epinephrine as postreperfusion syndrome (PRS) treatment (0.28 [0.17–0.32] vs. 0.17 [0.06–0.30] µg/kg, p = 0.010). However, there were no significant differences between groups in PRS and acute kidney injury incidences, mechanical ventilation duration, intensive care unit, and hospital lengths of stay. Multivariate analysis revealed a larger graft-to-recipient weight ratio (odds ratio [OR] 2.657, 95% confidence interval [CI], 1.132–6.239, p = 0.025) and intraoperative DEX administration (OR 0.333, 95% CI, 0.130–0.851, p = 0.022) to be independent predictors of moderate-to-extreme HIRI.ConclusionThis study demonstrated that intraoperative DEX could potentially decrease the risk of HIRI but was associated with a significant increase in epinephrine requirement for PRS in pediatric living-related LT. Further studies, including randomized controlled studies, are warranted to provide more robust evidence.

Activation of GPR81 Aggravates Remote Organ Injury During Hepatic Ischemia-Reperfusion Injury

Hepatic ischemia-reperfusion injury (HIRI) is a serious situation with high morbidity and mortality, which is usually accompanied with hyperlactatemia due to impaired lactate clearance in liver. G-protein-coupled receptor 81 (GPR81) has recently been identified as the bioactive receptor of lactate. GPR81 is profoundly involved in the modulation of metabolism and inflammation, but its significance in HIRI remains unclear. The present study investigated the potential roles of GPR81 in HIRI by using the GPR81 agonist 3-chloro-5-hydroxybenzoic acid (CHBA). The results indicated that treatment with CHBA had no obvious effects on HIRI-induced histologic abnormalities and elevation of serum aspartate aminotransferase, alanine aminotransferase. However, CHBA significantly upregulated the serum level of tumor necrosis factor alpha and interleukin-6 in mice with HIRI. Administration of CHBA also exacerbated HIRI-induced histologic lesions in lung, increased the level of myeloperoxidase in lung tissue and the protein concentration in bronchoalveolar lavage fluid. In addition, the serum levels of brain natriuretic peptide and creatinine also increased in CHBA-treated mice. The results indicate that activation of GPR81 might aggravate HIRI-induced remote organ injury and result in serious outcomes.

Precision Navigation of Hepatic Ischemia-Reperfusion Injury Guided by Lysosomal Viscosity-Activatable NIR-II Fluorescence.

Hepatic ischemia–reperfusion injury (HIRI) is responsible for postoperative liver dysfunction and liver failure. Precise and rapid navigation of HIRI lesions is critical for early warning and timely development of pretreatment plans. Available methods for assaying liver injury fail to provide the exact location of lesions in real time intraoperatively. HIRI is intimately associated with oxidative stress which impairs lysosomal degradative function, leading to significant changes in lysosomal viscosity. Therefore, lysosomal viscosity is a potential biomarker for the precise targeting of HIRI. Hence, we developed a viscosity-activatable second near-infrared window fluorescent probe (NP-V) for the detection of lysosomal viscosity in hepatocytes and mice during HIRI. A reactive oxygen species–malondialdehyde–cathepsin B signaling pathway during HIRI was established. We further conducted high signal-to-background ratio NIR-II fluorescence imaging of HIRI mice. The contour and boundary of liver lesions were delineated, and as such the precise intraoperative resection of the lesion area was implemented. This research demonstrates the potential of NP-V as a dual-functional probe for the elucidation of HIRI pathogenesis and the direct navigation of HIRI lesions in clinical applications.

Hepatoprotective Role of Carvedilol against Ischemic Hepatitis Associated with Acute Heart Failure via Targeting miRNA-17 and Mitochondrial Dynamics-Related Proteins: An In Vivo and In Silico Study.

Acute heart failure (AHF) is one of the most common diseases in old age that can lead to mortality. Systemic hypoperfusion is associated with hepatic ischemia–reperfusion injury, which may be irreversible. Ischemic hepatitis due to AHF has been linked to the pathogenesis of liver damage. In the present study, we extensively investigated the role of mitochondrial dynamics-related proteins and their epigenetic regulation in ischemic liver injury following AHF and explored the possible hepatoprotective role of carvedilol. The biochemical analysis revealed that the ischemic liver injury following AHF significantly elevated the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes, the level of total and direct bilirubin, and the expression of hepatic mitogen-activated protein kinase (MAPK), dynamin-1-like protein (DNM1L), and hepatic miRNA-17. At the same time, it significantly reduced the serum albumin level, the activity of hepatic superoxide dismutase (SOD), and the expression of mitochondrial peroxisome proliferator-activated receptor-1α (PGC-1α), and mitofusin 2 (Mtf2). The histological examination of the liver tissue revealed degenerated hepatocytes. Interestingly, administration of carvedilol either prior to or after isoprenaline-induced AHF significantly improved the liver function and reversed the deterioration effect of AHF-induced ischemic hepatitis, as demonstrated by biochemical, immunohistochemical, and histological analysis. Our results indicated that the hepatoprotective effect of carvedilol in ameliorating hepatic ischemic damage could be attributed to its ability to target the mitochondrial dynamics-related proteins (Mtf2, DNM1L and PGC-1α), but also their epigenetic regulator miRNA-17. To further explore the mode of action of carvedilol, we have investigated, in silico, the ability of carvedilol to target dynamin-1-like protein and mitochondrial dynamics protein (MID51). Our results revealed that carvedilol has a high binding affinity (−14.83 kcal/mol) toward the binding pocket of DNM1L protein. In conclusion, our study highlights the hepatoprotective pharmacological application of carvedilol to attenuate ischemic hepatitis associated with AHF.

β-Patchoulene Preconditioning Protects Mice Against Hepatic Ischemia-Reperfusion Injury by Regulating Nrf2/HO-1 Signaling Pathway.

Hepatic ischemia-reperfusion (I/R) injury is one of the main causes of liver dysfunction after the liver resection and transplantation. Hepatic I/R was characterized by the tissue hypoxia during ischemia phase and oxidative stress and immune response during hypoxia-reoxygenation. The objectives of the present study were to determine the protective effects of β-patchoulene (β-PAE), a novel bioactive agent, in a mice model of hepatic I/R injury and to explore its potential mechanisms. A segmental liver warm I/R injury model was performed by occluding the portal vessels for 1h followed by 6-h reperfusion. Twenty-four mice were randomly divided into three groups: Sham, I/R, and I/R+β-PAE, with eight mice in each group. Mice were intravenously injected with β-PAE (10mg/kg) or saline 2h before surgery, and parameters were measured 6h after designated treatment. Serum aminotransferase, histologic changes, cytokines expression, and apoptosis were determined. The potential effects of β-PAE on macrophage activation and apoptosis were further evaluated in a hypoxia and reperfusion (H/R) model invitro. Oxidative stress markers (reactive oxygen species production and malondialdehyde) and cytokines expression were measured by commercial kits. Nrf2/HO-1 and NF-ƘB signaling pathways were determined by Western blotting. Finally, blockade of nuclear factor erythroid 2-related factor 2 (Nrf2) with ML385 was used to confirm the involvement of Nrf2/HO-1 pathway in H/R injury. Hepatic I/R induced apparent tissue injury as evidenced by the increased expression of serum aminotransferase, pro-inflammatory mediators production, hepatocellular apoptosis, and necrosis. β-PAE pretreatment protected mice against I/R-induced injury, which was proved by decreased serum aminotransferase and cytokines production, reduced TUNEL-positive cells, and alleviated histopathological lesion. Immunofluorescence staining showed that β-PAE suppressed the M1 polarization of Kupffer cell induced by I/R injury. Moreover, pretreatment with β-PAE suppressed H/R-induced cytokines expression and apoptosis in cultured macrophage. The mechanistic study demonstrated that β-PAE significantly promoted the nuclear Nrf2 translocation and upregulation of HO-1 while downregulating the NF-ƘB signaling pathway in both invivo and invitro experiments. Furthermore, blockade of Nrf2 abolished the protective effects of β-PAE on the inhibition of H/R-mediated oxidative stress, inflammatory response, and apoptosis invitro. β-PAE preconditioning protects mice against hepatic I/R, which was at least in part through the reversing disequilibrium between Nrf2/HO-1 and NF-ƘB pathways. β-PAE might serve as a promising therapeutic agent in the treatment of hepatic I/R injury.

Protective effect of the combined use of L-carnitine and L-arginine against hepatic ischemia-reperfusion injury in rats

Protective effect of the combined use of L-carnitine and L-arginine against hepatic ischemia-reperfusion injury in rats

The Role of Neutrophils as a Driver in Hepatic Ischemia-Reperfusion Injury and Cancer Growth.

The innate immune system plays an essential role in the response to sterile inflammation and its association with liver ischemia and reperfusion injury (IRI). Liver IRI often manifests during times of surgical stress such as cancer surgery or liver transplantation. Following the initiation of liver IRI, stressed hepatocytes release damage-associated molecular patterns (DAMPs) which promote the infiltration of innate immune cells which then initiate an inflammatory cascade and cytokine storm. Upon reperfusion, neutrophils are among the first cells that infiltrate the liver. Within the liver, neutrophils play an important role in fueling tissue damage and tumor progression by promoting the metastatic cascade through the formation of Neutrophil Extracellular Traps (NETs). NETs are composed of web-like DNA structures containing proteins that are released in response to inflammatory stimuli in the environment. Additionally, NETs can aid in mediating liver IRI, promoting tumor progression, and most recently, in mediating early graft rejection in liver transplantation. In this review we aim to summarize the current knowledge of innate immune cells, with a focus on neutrophils, and their role in mediating IRI in mouse and human diseases, including cancer and transplantation. Moreover, we will investigate the interaction of Neutrophils with varying subtypes of other cells. Furthermore, we will discuss the role and different treatment modalities in targeting Neutrophils and NETs to prevent IRI.

Ellagic acid Alleviates hepatic ischemia–reperfusion injury in C57 mice via the Caspase-1-GSDMD pathway

BackgroundEllagic acid (EA) has improving function against oxidative damage and inflammatory reaction in many disorders. Hepatic ischemia–reperfusion injury (IRI) is a common pathophysiological phenomenon in the veterinary clinic. In the present study, the protective effects of EA pretreatment against hepatic IRI-induced injury and the underlying mechanisms were investigated.ResultsWe found that pyroptosis is involved in hepatic IRI, which is manifested in increasing the expression of pyroptosis-related genes and promoting the expression of active caspase-1, thereby cleaving GSDMD-N to cause pyroptosis, and caspase-1−/− mice were used to verify this conclusion. In addition, we found that EA protects against hepatic IRI by inhibiting pyroptosis, including reducing the activity of caspase-1 and its expression in the liver, inhibiting the lysis of GSDMD-N, and reducing the levels of IL-18 and IL-1β.ConclusionsThe present results have demonstrated that prophylactic administration of EA ameliorated hepatic IRI by inhibiting pyroptosis induced in hepatic ischemia–reperfusion in vivo through the caspase-1-GSDMD axis, providing a potential therapeutic option prevent hepatic IRI in pets.

Fluorescein clearance kinetics in blood and bile indicates hepatic ischemia-reperfusion injury in rats

Quantitative measurement of the degree of hepatic ischemia-reperfusion injury (IRI) is crucial for developing therapeutic strategies for its treatment. We hypothesized that clearance of fluorescent dye through bile metabolism may reflect the degree of hepatic IRI. In this study, we investigated sodium fluorescein clearance kinetics in blood and bile for quantifying the degree of hepatic IRI. Warm ischemia times (WITs) of 0, 30, or 60 min followed by 1 h or 4 h of reperfusion, were applied to the median and lateral lobes of the liver in Sprague-Dawley rats. Subsequently, 2 mg/kg of sodium fluorescein was injected intravenously, and blood and bile samples were collected over 60 min to measure fluorescence intensities. The bile-to-plasma fluorescence ratios demonstrated an inverse correlation with WIT and were distinctly lower in the 60-min WIT group than in the control or 30-min WIT groups. Bile-to-plasma fluorescence ratios displayed superior discriminability for short versus long WITs when measured 1 h after reperfusion versus 4 h. We conclude that the bile-to-blood ratio of fluorescence after sodium fluorescein injection has the potential to enable the quantification of hepatic IRI severity.NEW & NOTEWORTHY Previous attempts to use fluorophore clearance to test liver function have relied on a single source of data. However, the kinetics of substrate processing via bile metabolism include decreasing levels in blood and increasing levels in bile. Thus, we analyzed data from blood and bile to better reflect fluorescein clearance kinetics.

MiR-29a-3p in Exosomes from Heme Oxygenase-1 Modified Bone Marrow Mesenchymal Stem Cells Alleviates Steatotic Liver Ischemia-Reperfusion Injury in Rats by Suppressing Ferroptosis via Iron Responsive Element Binding Protein 2

Hepatic ischemia-reperfusion injury (IRI) is an inevitable result of liver surgery. Steatotic livers are extremely sensitive to IRI and have worse tolerance. Ferroptosis is considered to be one of the main factors of organ IRI. This study is aimed at exploring the role of ferroptosis in the effect of heme oxygenase-1-modified bone marrow mesenchymal stem cells (HO-1/BMMSCs) on steatotic liver IRI and its mechanism. An IRI model of a steatotic liver and a hypoxia reoxygenation (HR) model of steatotic hepatocytes (SHPs) were established. Rat BMMSCs were extracted and transfected with the Ho1 gene to establish HO-1/BMMSCs, and their exosomes were extracted by ultracentrifugation. Ireb2 was knocked down to verify its role in ferroptosis and cell injury in SHP-HR. Public database screening combined with quantitative real-time reverse transcription PCR identified microRNAs (miRNAs) targeting Ireb2 in HO-1/BMMSCs exosomes. miR-29a-3p mimic and inhibitor were used for functional verification experiments. Liver function, histopathology, terminal deoxynulceotidyl transferase nick-end-labeling staining, cell viability, mitochondrial membrane potential, and cell death were measured to evaluate liver tissue and hepatocyte injury. Ferroptosis was assessed by detecting the levels of IREB2, Fe2+, malondialdehyde, glutathione, lipid reactive oxygen species, glutathione peroxidase 4, prostaglandin-endoperoxide synthase 2 mRNA, and mitochondrial morphology. The results revealed that HO-1/BMMSCs improved liver tissue and hepatocyte injury and suppressed ferroptosis in vivo and in vitro. The expression of IREB2 was increased in steatotic liver IRI and SHP-HR. Knocking down Ireb2 reduced the level of Fe2+ and inhibited ferroptosis. HO-1/BMMSC exosomes reduced the expression of IREB2 and inhibited ferroptosis and cell damage. Furthermore, we confirmed high levels of miR-29a-3p in HO-1/BMMSCs exosomes. Overexpression of miR-29a-3p downregulated the expression of Ireb2 and inhibited ferroptosis. Downregulation of miR-29a-3p blocked the protective effect of HO-1/BMMSC exosomes on SHP-HR cell injury. In conclusion, ferroptosis plays an important role in HO-1/BMMSC-mediated alleviation of steatotic liver IRI. HO-1/BMMSCs could suppress ferroptosis by targeting Ireb2 via the exosomal transfer of miR-29a-3p.