Novel Targets and Therapeutic Strategies to Protect Against Hepatic Ischemia Reperfusion Injury

TXNIP knockdown ameliorates hepatic ischemia/reperfusion injury by inhibiting apoptosis and improving mitochondrial dysfunction via HIF-1α

This study aims to investigate whether thioredoxin-interacting protein (TXNIP) regulates cell viability, cell apoptosis and mitochondrial damage in OGD/R-induced hepatocytes and to explore its underlying mechanism. AML12 cells were cultured under oxygen-glucose deprivation/reperfusion (OGD/R) conditions. TXNIP mRNA was detected using qRT-PCR, and the TXNIP protein was analyzed using western blotting. TXNIP-targeted short hairpin RNA (sh-TXNIP) lentivirus was used to infect the AML12 cells. CCK8 and TUNEL assays were applied to detect cell viability and apoptosis, respectively. DCFH-DA probe was used to determine reactive oxygen species (ROS) release level, and JC-1 probe was used to evaluate mitochondrial membrane potential (MMP). The localization of TXNIP and HIF-1α was observed using immunofluorescence. Our results showed that TXNIP markedly increased in AML12 cells treated with OGD/R. TXNIP knockdown increased cell viability and reduced cell apoptosis under OGD/R treatment. Moreover, MMP significantly increased and ROS release decreased in cells after TXNIP knockdown under OGD/R treatment. Additionally, TXNIP knockdown markedly increased the expression of HIF-1α. HIF-1α exhibited nuclear translocation following OGD/R induction, and TXNIP knockdown further promoted it. Compared with the OGD/R + sh-TXNIP group, HIF-1α agonist ML228 inhibited cell apoptosis and ROS release, and increased MMP. However, HIF-1α inhibitor PX478 had the opposite effect. In summary, TXNIP deletion ameliorated AML12 cell injury caused by OGD/R via promoting HIF-1α expression and nuclear translocation, manifested by inhibiting cell apoptosis and alleviating mitochondrial dysfunction.

ERRFI1 exacerbates hepatic ischemia reperfusion injury by promoting hepatocyte apoptosis and ferroptosis in a GRB2-dependent manner

BACKGROUND

Programmed cell death is an important mechanism for the development of hepatic ischemia and reperfusion (IR) injury, and multiple novel forms of programmed cell death are involved in the pathological process of hepatic IR. ERRFI1 is involved in the regulation of cell apoptosis in myocardial IR. However, the function of ERRFI1 in hepatic IR injury and its modulation of programmed cell death remain largely unknown.

METHODS

Here, we performed functional and molecular mechanism studies in hepatocyte-specific knockout mice and ERRFI1-silenced hepatocytes to investigate the significance of ERRFI1 in hepatic IR injury. The histological severity of livers, enzyme activities, hepatocyte apoptosis and ferroptosis were determined.

RESULTS

ERRFI1 expression increased in liver tissues from mice with IR injury and hepatocytes under oxygen-glucose deprivation/reoxygenation (OGD/R) conditions. Hepatocyte-specific ERRFI1 knockout alleviated IR-induced liver injury in mice by reducing cell apoptosis and ferroptosis. ERRFI1 knockdown reduced apoptotic and ferroptotic hepatocytes induced by OGD/R. Mechanistically, ERRFI1 interacted with GRB2 to maintain its stability by hindering its proteasomal degradation. Overexpression of GRB2 abrogated the effects of ERRFI1 silencing on hepatocyte apoptosis and ferroptosis.

CONCLUSIONS

Our results revealed that the ERRFI1-GRB2 interaction and GRB2 stability are essential for ERRFI1-regulated hepatic IR injury, indicating that inhibition of ERRFI1 or blockade of the ERRFI1-GRB2 interaction may be potential therapeutic strategies in response to hepatic IR injury.

Modafinil lightens apoptosis and inflammatory response in hepatic ischemia-reperfusion injury through inactivation of TLR9/Myd88/p38 signaling

Hepatic ischemia/reperfusion injury (IRI) remains a severe threat during liver surgery and transplantation, accounting for unfavorable clinical outcomes. Modafinil (MOD), a wakefulness-inducing compound, is increasingly disclosed to protect against IRI. However, the specific literatures covering the association between MOD and hepatic IRI are few. Here, this paper is committed to unraveling the role and response mechanism of MOD in hepatic IRI. After the establishment of hepatic IRI mice model and cell model, relevant assay kits measured the concentrations of biochemical indicators of hepatotoxicity and hematoxylin and eosin staining estimated liver morphology. Enzyme-linked immunosorbent assay, reverse-transcription quantitative polymerase chain reaction, and western blot evaluated inflammatory levels. Terminal-deoxynucleoitidyl transferase-mediated nick end labeling assay and western blot appraised apoptosis. Western blot also analyzed the expression of Toll-like receptor 9 (TLR9)/myeloid differentiation primary response gene 88 (MyD88)/p38 signaling-associated proteins. Cell counting kit-8 method judged cell viability. MOD was discovered to mitigate liver dysfunction and morphological damage, inflammatory response, apoptosis in vivo and improve cell viability, suppress inflammatory response and apoptosis in vitro. In addition, MOD inactivated TLR9/Myd88/p38 signaling both in vitro and in vivo. Further, TLR9 elevation reversed the inhibitory role of MOD in inflammatory response and cell apoptosis in vitro. Anyway, MOD blocked TLR9/Myd88/p38 signaling to exhibit anti-inflammatory and anti-apoptotic properties in hepatic IRI.

GDF11: An emerging therapeutic target for liver diseases and fibrosis

Growth differentiation factor 11 (GDF11), also known as bone morphogenetic protein 11 (BMP11), has been identified as a key player in various biological processes, including embryonic development, aging, metabolic disorders and cancers. GDF11 has also emerged as a critical component in liver development, injury and fibrosis. However, the effects of GDF11 on liver physiology and pathology have been a subject of debate among researchers due to conflicting reported outcomes. While some studies suggest that GDF11 has anti-aging properties, others have documented its senescence-inducing effects. Similarly, while GDF11 has been implicated in exacerbating liver injury, it has also been shown to have the potential to reduce liver fibrosis. In this narrative review, we present a comprehensive report of recent evidence elucidating the diverse roles of GDF11 in liver development, hepatic injury, regeneration and associated diseases such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), liver fibrosis and hepatocellular carcinoma. We also explore the therapeutic potential of GDF11 in managing various liver pathologies.

Modification of Preservative Fluids with Antioxidants in Terms of Their Efficacy in Liver Protection before Transplantation

Transplantation is currently the only effective treatment for patients with end-stage liver failure. In recent years, many advanced studies have been conducted to improve the efficiency of organ preservation techniques. Modifying the composition of the preservation fluids currently used may improve graft function and increase the likelihood of transplantation success. The modified fluid is expected to extend the period of safe liver storage in the peri-transplantation period and to increase the pool of organs for transplantation with livers from marginal donors. This paper provides a literature review of the effects of antioxidants on the efficacy of liver preservation fluids. Medline (PubMed), Scopus, and Cochrane Library databases were searched using a combination of MeSH terms: "liver preservation", "transplantation", "preservation solution", "antioxidant", "cold storage", "mechanical perfusion", "oxidative stress", "ischemia-reperfusion injury". Studies published up to December 2023 were included in the analysis, with a focus on publications from the last 30 years. A total of 45 studies met the inclusion criteria. The chemical compounds analyzed showed mostly bioprotective effects on hepatocytes, including but not limited to multifactorial antioxidant and free radical protective effects. It should be noted that most of the information cited is from reports of studies conducted in animal models, most of them in rodents.

Novel gene-based therapeutic approaches for the management of hepatic complications in diabetes: Reviewing recent advances

Diabetes mellitus is a chronic metabolic disorder marked by hyperglycemia and systemic complications, including hepatic dysfunction, significantly contributing to disease progression and morbidity. This article reviews recent advances in gene-based therapeutic strategies targeting hepatic complications in diabetes, offering a promising approach for precision medicine by addressing underlying molecular mechanisms. Traditional treatments for hepatic complications in diabetes often manage symptoms rather than molecular causes, showing limited efficacy. Gene-based therapies are poised to correct dysfunctional pathways and restore hepatic function. Fundamental gene therapy approaches include gene silencing via small interfering RNAs (siRNAs) to target hepatic glucose production, lipid metabolism, and inflammation. Viral vectors can restore insulin sensitivity and reduce oxidative stress in diabetic livers. Genome editing, especially CRISPR-Cas9, allows the precise modification of disease-associated genes, offering immense potential for hepatic complication treatment. Strategies using CRISPR-Cas9 to enhance insulin receptor expression and modulate aberrant lipid regulatory genes are explored. Safety challenges in gene-based therapies, such as off-target effects and immune responses, are discussed. Advances in nanoparticle-based delivery systems and targeted gene editing techniques offer solutions to enhance specificity and minimize adverse effects. In conclusion, gene-based therapeutic approaches are a transformative direction in managing hepatic complications in diabetes. Further research is needed to optimize efficacy, safety, and long-term outcomes. Nevertheless, these innovative strategies promise to improve the lives of individuals with diabetes by addressing hepatic dysfunction's genetic root causes.

Carbon dot nanozymes as free radicals scavengers for the management of hepatic ischemia-reperfusion injury by regulating the liver inflammatory network and inhibiting apoptosis

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) is a pathophysiological process during liver transplantation, characterized by insufficient oxygen supply and subsequent restoration of blood flow leading to an overproduction of reactive oxygen species (ROS), which in turn activates the inflammatory response and leads to cellular damage. Therefore, reducing excess ROS production in the hepatic microenvironment would provide an effective way to mitigate oxidative stress injury and apoptosis during HIRI. Nanozymes with outstanding free radical scavenging activities have aroused great interest and enthusiasm in oxidative stress treatment.

RESULTS

We previously demonstrated that carbon-dots (C-dots) nanozymes with SOD-like activity could serve as free radicals scavengers. Herein, we proposed that C-dots could protect the liver from ROS-mediated inflammatory responses and apoptosis in HIRI, thereby improving the therapeutic effect. We demonstrated that C-dots with anti-oxidative stress and anti-inflammatory properties improved the survival of L-02 cells under H2O2 and LPS-treated conditions. In the animal model, Our results showed that the impregnation of C-dots could effectively scavenge ROS and reduce the expression of inflammatory cytokines, such as IL-1β, IL-6, IL-12, and TNF-α, resulting in a profound therapeutic effect in the HIRI. To reveal the potential therapeutic mechanism, transcriptome sequencing was performed and the relevant genes were validated, showing that the C-dots exert hepatoprotective effects by modulating the hepatic inflammatory network and inhibiting apoptosis.

CONCLUSIONS

With negligible systemic toxicity, our findings substantiate the potential of C-dots as a therapeutic approach for HIRI, thereby offering a promising intervention strategy for clinical implementation.

The role of ischaemia-reperfusion injury and liver regeneration in hepatic tumour recurrence

The risk of cancer recurrence after liver surgery mainly depends on tumour biology, but preclinical and clinical evidence suggests that the degree of perioperative liver injury plays a role in creating a favourable microenvironment for tumour cell engraftment or proliferation of dormant micro-metastases. Understanding the contribution of perioperative liver injury to tumour recurrence is imperative, as these pathways are potentially actionable. In this review, we examine the key mechanisms of perioperative liver injury, which comprise mechanical handling and surgical stress, ischaemia-reperfusion injury, and parenchymal loss leading to liver regeneration. We explore how these processes can trigger downstream cascades leading to the activation of the immune system and the pro-inflammatory response, cellular proliferation, angiogenesis, anti-apoptotic signals, and release of circulating tumour cells. Finally, we discuss the novel therapies under investigation to decrease ischaemia-reperfusion injury and increase regeneration after liver surgery, including pharmaceutical agents, inflow modulation, and machine perfusion.

Mitogen activated protein kinase phosphatase 5 alleviates liver ischemia-reperfusion injury by inhibiting TAK1/JNK/p38 pathway

Mitogen activated protein kinase phosphatase 5 (MKP5) is a member of the MKP family and has been implicated in diverse biological and pathological conditions. However, it is unknown what role MKP5 plays in liver ischemia/reperfusion (I/R) injury. In the present study, we used MKP5 global knockout (KO) and MKP5 overexpressing mice to establish a liver I/R injury model in vivo, and MKP5 knockdown or MKP5 overexpressing HepG2 cells to establish a hypoxia-reoxygenation (H/R) model in vitro. In this study we demonstrated that protein expression of MKP5 was significantly downregulated in liver tissue of mice after I/R injury, and HepG2 cells subjected to H/R injury. MKP5 KO or knockdown significantly increased liver injury, as demonstrated by elevated serum transaminases, hepatocyte necrosis, infiltrating inflammatory cells, secretion of pro-inflammatory cytokines, apoptosis, oxidative stress. Conversely, MKP5 overexpression significantly attenuated liver and cell injury. Furthermore, we showed that MKP5 exerted its protective effect by inhibiting c-Jun N-terminal kinase (JNK)/p38 activity, and its action was dependent on Transforming growth factor-β-activated kinase 1 (TAK1) activity. According to our results, MKP5 inhibited the TAK1/JNK/p38 pathway to protect liver from I/R injury. Our study identifies a novel target for the diagnosis and treatment of liver I/R injury.

The Protective Effect of Nutraceuticals on Hepatic Ischemia-Reperfusion Injury in Wistar Rats

Nutraceuticals are bioactive compounds present in foods, utilized to ameliorate health, prevent diseases, and support the proper functioning of the human body. They have gained attention due to their ability to hit multiple targets and act as antioxidants, anti-inflammatory agents, and modulators of immune response and cell death. Therefore, nutraceuticals are being studied to prevent and treat liver ischemia-reperfusion injury (IRI). This study evaluated the effect of a nutraceutical solution formed by resveratrol, quercetin, omega-3 fatty acid, selenium, ginger, avocado, leucine, and niacin on liver IRI. IRI was performed with 60 min of ischemia and 4 h of reperfusion in male Wistar rats. Afterward, the animals were euthanized to study hepatocellular injury, cytokines, oxidative stress, gene expression of apoptosis-related genes, TNF-α and caspase-3 proteins, and histology. Our results show that the nutraceutical solution was able to decrease apoptosis and histologic injury. The suggested mechanisms of action are a reduction in gene expression and the caspase-3 protein and a reduction in the TNF-α protein in liver tissue. The nutraceutical solution was unable to decrease transaminases and cytokines. These findings suggest that the nutraceuticals used favored the protection of hepatocytes, and their combination represents a promising therapeutic proposal against liver IRI.

Downregulation of Bmal1 Expression in Celiac Ganglia Protects against Hepatic Ischemia-Reperfusion Injury

Hepatic ischemia-reperfusion injury (HIRI) significantly contributes to liver dysfunction following liver transplantation and hepatectomy. However, the role of the celiac ganglion (CG) in HIRI remains unclear. Adeno-associated virus was used to silence Bmal1 expression in the CG of twelve beagles that were randomly assigned to the Bmal1 knockdown group (KO-Bmal1) and the control group. After four weeks, a canine HIRI model was established, and CG, liver tissue, and serum samples were collected for analysis. The virus significantly downregulated Bmal1 expression in the CG. Immunofluorescence staining confirmed a lower proportion of c-fos⁺ and NGF⁺ neurons in TH⁺ cells in the KO-Bmal1 group than in the control group. The KO-Bmal1 group exhibited lower Suzuki scores and serum ALT and AST levels than the control group. Bmal1 knockdown significantly reduced liver fat reserve, hepatocyte apoptosis, and liver fibrosis, and it increased liver glycogen accumulation. We also observed that Bmal1 downregulation inhibited the hepatic neurotransmitter norepinephrine, neuropeptide Y levels, and sympathetic nerve activity in HIRI. Finally, we confirmed that decreased Bmal1 expression in CG reduces TNF-α, IL-1β, and MDA levels and increases GSH levels in the liver. The downregulation of Bmal1 expression in CG suppresses neural activity and improves hepatocyte injury in the beagle model after HIRI.

MiR-130a-3p regulates FUNDC1-mediated mitophagy by targeting GJA1 in myocardial ischemia/reperfusion injury

Understanding the complex pathogenesis in myocardial ischemia/reperfusion (I/R) injury (IRI) is an urgent problem in clinical trials. Increasing pieces of evidence have suggested that miRNAs are involved in the occurrence and development of heart diseases by regulating mitochondria-related gene expression. Mitochondria have been acknowledged as the key triggers of cardiac I/R injury. However, the potential impact of miR-130a on mitochondria remains unclear in myocardial IRI. Exploring the regulatory mechanism of miR-130a on mitochondria may provide a new target for IRI therapy. In the present study, we found that miR-130a significantly increased in acute myocardial infarction (AMI) patients and myocardial I/R rats. MiR-130a could downregulate the viability of cardiomyocytes and the knockdown of miR-130a could protect the viability of cardiomyocytes under hypoxia-reoxygenation (HR). Over-expression of miR-130a resulted in mitochondrial dysfunction. It was evidenced by decreases in mitochondrial ATP production, mitochondrial membrane potential (MMP), and an increase in reactive oxygen species (ROS) production. However, suppression of miR-130a could protect against mitochondrial damage, show elevation of mitochondrial ATP production rate and MMP, and reduce ROS production. We further explored the effect of miR-130a on the mitochondrial quality control (QMC) system by determining mitochondrial-protein-specific proteases and analyzed mitochondrial morphology by fluorescence imaging and electron microscopy, respectively. It was noted that miR-130a could suppress mitochondrial fusion and FUNDC1-mediated mitophagy to accelerate myocardial IRI. Moreover, we investigated the potential miR-130a targeted mitochondria-related genes to understand the regulatory mechanism of miR-130a in the setting of myocardial IRI. It was revealed that miR-130a targeted GJA1, and GJA1 rescued IRI by enhancing ATP production rate and oxidative phosphorylation, meanwhile protecting cell viability, MMP, and activating mitophagy. In addition, the knockdown of miR-130a significantly activated FUNDC1-mediated mitophagy, while the knockdown of GJA1 reversed the relevant response. Collectively, our findings suggest that miR-130a regulates FUNDC1-mediated mitophagy by targeting GJA1 in myocardial IRI.

DUSP9 alleviates hepatic ischemia/reperfusion injury by restraining both mitogen-activated protein kinase and IKK in an apoptosis signal-regulating kinase 1-dependent manner

Hepatic ischemia/reperfusion (I/R) injury occurs frequently in various liver operations and diseases, but its effective treatment remains inadequate because the key switch that leads to hepatic explosive inflammation has not been well disclosed. Dual specificity phosphatase 9 (DUSP9) is widely involved in the innate immune response of solid organs and is sometimes regulated by ubiquitin. In the present study, we find that DUSP9 is reduced in mouse hepatic I/R injury. DUSP9 enrichment attenuates hepatic inflammation both in vivo and in vitro as revealed by western blot analysis and qRT-PCR. In contrast, DUSP9 depletion leads to more severe I/R injury. Mechanistically, DUSP9 inhibits the phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) by directly binding to ASK1, thereby decreasing tumor necrosis factor receptor-associated factor 6 (TRAF6), K63 ubiquitin and the phosphorylation of p38/JNK1 instead of ERK1. The present study documents a novel role of DUSP9 in hepatic I/R injury and implies the potential of targeting the DUSP9/ASK1 axis towards mitogen-activated protein kinase and TRAF6/inhibitor of κB kinase pathways.

Bioinformatics analysis of genes related to ferroptosis in hepatic ischemia-reperfusion injury

Background: Primary liver cancer is the sixth most commonly diagnosed cancer and the third leading cause of cancer death worldwide in 2020, and it ranks fifth in global incidence. Liver resection or liver transplantation are the two most prominent surgical procedures for treating primary liver cancer. Both inevitably result in HIRI, causing severe complications for patients and affecting their prognosis and quality of survival. Ferroptosis, a newly discovered mode of cell death, is closely related to HIRI. We used bioinformatics analysis to explore the relationship between the two further. Methods: The GEO database dataset GSE112713 and the FerrDB database data were selected to use bioinformatic analysis methods (difference analysis, FRGs identification, GO analysis, KEGG analysis, PPI network construction and analysis, Hub gene screening with GO analysis and KEGG analysis, intergenic interaction prediction, drug-gene interaction prediction, miRNA prediction) for both for correlation analysis. The GEO database dataset GSE15480 was selected for preliminary validation of the screened Hub genes. Results: We analysed the dataset GSE112713 for differential gene expression before and after hepatic ischemia-reperfusion and identified by FRGs, yielding 11 genes. These 11 genes were subjected to GO, and KEGG analyses, and PPI networks were constructed and analysed. We also screened these 11 genes again to obtain 5 Hub genes and performed GO analysis, KEGG analysis, intergenic interaction prediction, drug-gene interaction prediction, and miRNA prediction on these 5 Hub genes. Finally, we obtained preliminary validation of all these 5 Hub genes by dataset GSE15480. Conclusion: There is a close relationship between HIRI and ferroptosis, and inhibition of ferroptosis can potentially be a new approach to mitigate HIRI treatment in the future.

Prussian Blue Scavenger Ameliorates Hepatic Ischemia-Reperfusion Injury by Inhibiting Inflammation and Reducing Oxidative Stress

Oxidative stress and excessive inflammatory responses are the two critical mechanisms of hepatic ischemia-reperfusion injury (HIRI) encountered in many clinical settings, including following hepatectomy and liver transplantation. Effective anti-inflammatory and anti-oxidative pharmacological interventions are urgently needed to counter HIRI. The present study showed that a biocompatible Prussian blue (PB) scavenger with reactive oxygen species (ROS) scavenging and anti-inflammatory properties might be used a promising treatment for HIRI. Following intravenous administration, PB scavenger was mainly distributed in the liver, where it showed excellent ability to alleviate apoptosis, tissue injury and organ dysfunction after HIRI. PB scavenger was found to protect liver tissue by scavenging ROS, reducing neutrophil infiltration and promoting macrophage M2 polarization. In addition, PB scavenger significantly reduced oxidative stress in primary hepatocytes, restoring cell viability under oxidative stress condition. PB scavenger effectively reduced lipopolysaccharide-stimulated inflammation in RAW 264.7 cells. These findings indicate that PB scavenger may be a potential therapeutic agent for the treatment of HIRI, providing an alternative treatment for ROS-associated and inflammatory liver diseases.

Natural Killer Cells in Hepatic Ischemia-Reperfusion Injury

Ischemia-reperfusion injury can be divided into two phases, including insufficient supply of oxygen and nutrients in the first stage and then organ injury caused by immune inflammation after blood flow recovery. Hepatic ischemia-reperfusion is an important cause of liver injury post-surgery, consisting of partial hepatectomy and liver transplantation, and a central driver of graft dysfunction, which greatly leads to complications and mortality after liver transplantation. Natural killer (NK) cells are the lymphocyte population mainly involved in innate immune response in the human liver. In addition to their well-known role in anti-virus and anti-tumor defense, NK cells are also considered to regulate the pathogenesis of liver ischemia-reperfusion injury under the support of more and more evidence recently. The infiltration of NK cells into the liver exacerbates the hepatic ischemia-reperfusion injury, which could be significantly alleviated after depletion of NK cells. Interestingly, NK cells may contribute to both liver graft rejection and tolerance according to their origins. In this article, we discussed the development of liver NK cells, their role in ischemia-reperfusion injury, and strategies of inhibiting NK cell activation in order to provide potential possibilities for translation application in future clinical practice.

MicroRNAs: Novel Targets in Hepatic Ischemia–Reperfusion Injury

Hepatic ischemia–reperfusion injury (IRI) is one of the main factors for early allograft dysfunction (EAD), which may lead to graft rejection, graft loss, or shortened graft life in liver transplantation. Hepatic IRI appears to be inevitable during the majority of liver procurement and transportation of donor organs, resulting in a cascade of biological changes. The activation of signaling pathways during IRI results in the up- and downregulation of genes and microRNAs (miRNAs). miRNAs are ~21 nucleotides in length and well-characterized for their role in gene regulations; they have recently been used for therapeutic approaches in addition to their role as biomarkers for many diseases. miRNAs that are associated with hepatic IRI in in vitro and in vivo animal models are comprehensively summarized in this review. In those studies, the manipulation of miRNAs has been shown for the inhibition of aggravated immune response, reduction of apoptosis, stimulation of tissue repair, and enhancement of cell recovery to attenuate liver damage. Therefore, the utilization of liver-specific miRNA holds great potential as a therapeutic agent to improve early allograft dysfunction, hepatic injury, and patient outcome.