Inhibition of inflammatory liver injury by the HMGB1-A box through HMGB1/TLR-4/NF-κB signaling in an acute liver failure mouse model

Piezo1 deficiency alleviates acute liver failure by inhibiting CpG-ODN induced inflammatory responses

Macrophages play a critical role in the progression of acute liver failure (ALF), a life-threatening clinical syndrome characterized by the rapid onset of liver injury. Recent research suggests that mechanosensation signaling may be pivotal in modulating acute inflammation. However, its involvement in ALF pathogenesis remains poorly understood. In this study, we found that Piezo1 was highly expressed in liver macrophages during liver injury in both humans and mice. Mice with macrophage-specific Piezo1 depletion were resistant to CpG-ODN/D-GalN-induced ALF, whereas mice pretreated with Yoda1 showed increased susceptibility. Furthermore, Piezo1-deficient macrophages exhibited reduced secretion of inflammatory cytokines upon CpG-ODN stimulation in vitro, while Yoda1 treatment enhanced cytokine secretion. Mechanistically, Piezo1 activation promotes the phosphorylation of CaMKII, which further enhances CpG-ODN-induced NF-κB activation. Additionally, Piezo1 activation promotes the endosomal translocation of TLR9 through the cytoskeleton remodeling. These findings suggest that Piezo1-mediated mechanosensation contributes to the development of CpG-ODN/D-GalN-induced ALF and may serve as a potential therapeutic target.

HPLC-HRMS/MS and anti-inflammatory effects of bunya pine resin through multifaceted pathway modulation: NUMB/NOTCH1/HES1/mTOR/ PI3K/HMGB1 signaling cascades

The oleoresins of the Araucaria bidwillii Hook. (A.B.) are commonly used for the treatment of several conditions. However, the full phytochemical profile of its active compounds and its mechanism of action to protect the liver from toxicity remain unclear. The purpose of this research was to investigate the complete set of data relating to the A.B. active metabolites and explore the hepatoprotective properties of AB ethanolic extract on MTX-induced liver injury mainly due to its anti-inflammatory role. Hepatic markers, oxidative stress, inflammatory mediators, the NOTCH/NICD signaling cascade, HES1 expression, HMGB1/TLR4, and the PI3K/mTOR axis were assessed. HPLC-HRMS/MS analysis of A.B. led to the annotation of fifteen compounds from different classes, where diterpenes are the dominant class. Additionally, A.B. (100 and 200 mg/kg) significantly decreased hepatic markers, oxidative stress, and inflammatory mediators. Moreover, the extract significantly increased NOTCH pathway stimulation and HES1 expression, accompanied by a significant decline in the NUMB and HMGB1/TLR4 axes. In addition, it significantly inhibited the PI3K/mTOR pathway, with a prominent effect at the higher dose. This study presents A.B. as a promising hepatoprotective agent through stimulation of the NOTCH pathway and inhibition of the HMGB1/TLR4 pathway, as well as the PI3K/mTOR/NF-κB axis, besides its antioxidant and anti-inflammatory effects.

Induction of ferroptosis by SIRT1 knockdown alleviates cytarabine resistance in acute myeloid leukemia by activating the HMGB1/ACSL4 pathway

Resistance to cytarabine is a major obstacle to the successful treatment of acute myeloid leukemia (AML). The present study aimed to explore the mechanism by which sirtuin 1 (SIRT1) reverses the cytarabine resistance of leukemia cells. Cell viability was investigated using the EdU proliferation assay. The expression levels of molecules were determined by reverse transcription‑quantitative PCR, western blotting, and immunofluorescence staining. Flow cytometry was used to detect reactive oxygen species and apoptosis levels, The levels of superoxide dismutase, glutathione and malondialdehyde were examined by ELISA. Mitochondrial damage was investigated by transmission electron microscopy. Furthermore, tumor growth was evaluated in a xenograft model. The results revealed that SIRT1 expression was significantly upregulated in drug‑resistant leukemia cells. By contrast, knockdown of SIRT1 reversed cytarabine resistance in HL60 cells by promoting ferroptosis. Mechanistically, SIRT1 could regulate the translocation of HMGB1 from the nucleus to the cytoplasm in cytarabine‑resistant HL60 (HL60/C) cells. Furthermore, knockdown of HMGB1 inhibited the expression of ACSL4. In addition, knockdown of SIRT1 expression could inhibit the growth of HL60/C cells in vivo and reverse cytarabine resistance. In conclusion, the present results demonstrated that SIRT1 inhibition could be a promising strategy to overcome cytarabine resistance in AML.

Emerging Roles of High-mobility Group Box-1 in Liver Disease

High-mobility group box-1 (HMGB1) is an architectural chromosomal protein with various roles depending on its cellular localization. Extracellular HMGB1 functions as a prototypical damage-associated molecular pattern that triggers inflammation and adaptive immune responses, mediated by specific cell surface receptors, including receptors for advanced glycation end products and toll-like receptors. Post-translational modifications of HMGB1 significantly impact various cellular processes that contribute to the pathogenesis of liver diseases. Recent studies have highlighted the close relationship between HMGB1 and the pathogenesis of acute liver injuries, including acetaminophen-induced liver injury, hepatic ischemia-reperfusion injury, and acute liver failure. In chronic liver diseases, HMGB1 plays a role in nonalcoholic fatty liver disease, alcohol-associated liver disease, liver fibrosis, and hepatocellular carcinoma. Targeting HMGB1 as a therapeutic approach, either by inhibiting its release or blocking its extracellular function, is a promising strategy for treating liver diseases. This review aimed to summarize the available evidence on HMGB1's role in liver disease, focusing on its multifaceted signaling pathways, impact on disease progression, and the translation of these findings into clinical interventions.

Berberine attenuates ECM accumulation and the progression of acute liver failure through inhibition of NLRP3 inflammasome signalling

Acute liver failure (ALF) is a life-threatening disease, characterized by upregulated extracellular matrix deposition and inflammatory signalling, with no effective treatment options and targets. The present study was designed to investigate the preventive and therapeutic effects of berberine (BBR) and its underlying mechanism in thioacetamide (TAA)-induced ALF. Male SD rats were administered with TAA 300 mg/kg, i.p., thrice to induce ALF and pre- or post-treated with BBR. To decipher the effects of BBR LFT markers, histopathological analysis of key fibrotic and inflammatory proteins was performed. In addition, the levels of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α were assessed by ELISA. Our work showed TAA-induced ALF animals were associated with increased ALT, AST, bilirubin (LFT markers) and histopathological alterations with profuse infiltration of inflammatory cells in the liver tissue. Treatment with BBR has significantly inhibited LFT markers and histological alterations triggered by TAA. In addition, TAA animals demonstrated increased collagen accumulation and upregulated expression of TGF-β1, vimentin, and α-SMA compared to control. The excessive accumulation of collagen, TGF-β1, vimentin, and α-SMA were significantly modulated with BBR treatment. Further, the fluorescence intensity of ROS an activator of NLRP3 including the NLRP3 inflammasome, and its downstream signalling ASC, cleaved IL-1β, and other pro-inflammatory cytokines like TNF-α and IL-6 stimulated by TAA were attenuated by BBR treatment. The current work indicated that BBR significantly ameliorated TAA-induced ALF by inhibiting the extracellular matrix accumulation associated with the NLRP3/IL-1β signalling pathway and could be a viable therapeutic option to treat ALF and other fibroinflammatory diseases.

Research progress on rodent models and its mechanisms of liver injury

The liver is the most important organ for biological transformation in the body and is crucial for maintaining the body's vital activities. Liver injury is a serious pathological condition that is commonly found in many liver diseases. It has a high incidence rate, is difficult to cure, and is prone to recurrence. Liver injury can cause serious harm to the body, ranging from mild to severe fatty liver disease. If the condition continues to worsen, it can lead to liver fibrosis and cirrhosis, ultimately resulting in liver failure or liver cancer, which can seriously endanger human life and health. Therefore, establishing an rodent model that mimics the pathogenesis and severity of clinical liver injury is of great significance for better understanding the pathogenesis of liver injury patients and developing more effective clinical treatment methods. The author of this article summarizes common chemical liver injury models, immune liver injury models, alcoholic liver injury models, drug-induced liver injury models, and systematically elaborates on the modeling methods, mechanisms of action, pathways of action, and advantages or disadvantages of each type of model. The aim of this study is to establish reliable rodent models for researchers to use in exploring anti-liver injury and hepatoprotective drugs. By creating more accurate theoretical frameworks, we hope to provide new insights into the treatment of clinical liver injury diseases.

Advances in the study of acetaminophen-induced liver injury

Acetaminophen (APAP) overdose is a significant cause of drug-induced liver injury and acute liver failure. The diagnosis, screening, and management of APAP-induced liver injury (AILI) is challenging because of the complex mechanisms involved. Starting from the current studies on the mechanisms of AILI, this review focuses on novel findings in the field of diagnosis, screening, and management of AILI. It highlights the current issues that need to be addressed. This review is supposed to summarize the recent research progress and make recommendations for future research.

Progress of research on the role of active ingredients of Citri Reticulatae Pericarpium in liver injury

BACKGROUND

Liver is a vital organ responsible for metabolizing and detoxifying both endogenous and exogenous substances in the body. However, it is susceptible to damage from chemical and natural toxins. The high incidence and mortality rates of liver disease and its associated complications impose a significant economic burden and survival pressure on patients and their families. Various liver diseases exist, including cholestasis, viral and non-viral hepatitis, fatty liver disease, drug-induced liver injury, alcoholic liver injury, and severe end-stage liver diseases such as cirrhosis, hepatocellular carcinoma (HCC), and cholangiocellular carcinoma (CCA). Recent research has shown that flavonoids found in Citri Reticulatae Pericarpium (CRP) have the potential to normalize blood glucose, cholesterol levels, and liver lipid levels. Additionally, these flavonoids exhibit anti-inflammatory properties, prevent oxidation and lipid peroxidation, and reduce liver toxicity, thereby preventing liver injury. Given these promising findings, it is essential to explore the potential of active components in CRP for developing new drugs to treat liver diseases.

OBJECTIVE

Recent studies have revealed that flavonoids, including hesperidin (HD), hesperetin (HT), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangerine (TN), and erodcyol (ED), are the primary bioactive components in CRP. These flavonoids exhibit various therapeutic effects on liver injury, including anti-oxidative stress, anti-cytotoxicity, anti-inflammatory, anti-fibrosis, and anti-tumor mechanisms. In this review, we have summarized the research progress on the hepatoprotective effects of HD, HT, NIN, NOB, NRG, TN, ED and limonene (LIM), highlighting their underlying molecular mechanisms. Despite their promising effects, the current clinical application of these active ingredients in CRP has some limitations. Therefore, further studies are needed to explore the full potential of these flavonoids and develop new therapeutic strategies for liver diseases.

METHODS

For this review, we conducted a systematic search of three databases (ScienceNet, PubMed, and Science Direct) up to July 2022, using the search terms "CRP active ingredient," "liver injury," and "flavonoids." The search data followed the PRISMA standard.

RESULTS

Our findings indicate that flavonoids found in CRP can effectively reduce drug-induced liver injury, alcoholic liver injury, and non-alcoholic liver injury. These therapeutic effects are mainly attributed to the ability of flavonoids to improve liver resistance to oxidative stress and inflammation while normalizing cholesterol and liver lipid levels by exhibiting anti-free radical and anti-lipid peroxidation properties.

CONCLUSION

Our review provides new insights into the potential of active components in CRP for preventing and treating liver injury by regulating various molecular targets within different cell signaling pathways. This information can aid in the development of novel therapeutic strategies for liver disease.

Orchestrated regulation of immune inflammation with cell therapy in pediatric acute liver injury

Acute liver injury (ALI) in children, which commonly leads to acute liver failure (ALF) with the need for liver transplantation, is a devastating life-threatening condition. As the orchestrated regulation of immune hemostasis in the liver is essential for resolving excess inflammation and promoting liver repair in a timely manner, in this study we focused on the immune inflammation and regulation with the functional involvement of both innate and adaptive immune cells in acute liver injury progression. In the context of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, it was also important to incorporate insights from the immunological perspective for the hepatic involvement with SARS-CoV-2 infection, as well as the acute severe hepatitis of unknown origin in children since it was first reported in March 2022. Furthermore, molecular crosstalk between immune cells concerning the roles of damage-associated molecular patterns (DAMPs) in triggering immune responses through different signaling pathways plays an essential role in the process of liver injury. In addition, we also focused on DAMPs such as high mobility group box 1 (HMGB1) and cold-inducible RNA-binding protein (CIRP), as well as on macrophage mitochondrial DNA-cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway in liver injury. Our review also highlighted novel therapeutic approaches targeting molecular and cellular crosstalk and cell-based therapy, providing a future outlook for the treatment of acute liver injury.

HMGB1 cleavage by complement C1s and its potent anti-inflammatory product

Complement C1s association with the pathogenesis of several diseases cannot be simply explained only by considering its main role in activating the classical complement pathway. This suggests that non-canonical functions are to be deciphered for this protease. Here the focus is on C1s cleavage of HMGB1 as an auxiliary target. HMGB1 is a chromatin non-histone nuclear protein, which exerts in fact multiple functions depending on its location and its post-translational modifications. In the extracellular compartment, HMGB1 can amplify immune and inflammatory responses to danger associated molecular patterns, in health and disease. Among possible regulatory mechanisms, proteolytic processing could be highly relevant for HMGB1 functional modulation. The unique properties of HMGB1 cleavage by C1s are analyzed in details. For example, C1s cannot cleave the HMGB1 A-box fragment, which has been described in the literature as an inhibitor/antagonist of HMGB1. By mass spectrometry, C1s cleavage was experimentally identified to occur after lysine on position 65, 128 and 172 in HMGB1. Compared to previously identified C1s cleavage sites, the ones identified here are uncommon, and their analysis suggests that local conformational changes are required before cleavage at certain positions. This is in line with the observation that HMGB1 cleavage by C1s is far slower when compared to human neutrophil elastase. Recombinant expression of cleavage fragments and site-directed mutagenesis were used to confirm these results and to explore how the output of C1s cleavage on HMGB1 is finely modulated by the molecular environment. Furthermore, knowing the antagonist effect of the isolated recombinant A-box subdomain in several pathophysiological contexts, we wondered if C1s cleavage could generate natural antagonist fragments. As a functional readout, IL-6 secretion following moderate LPS activation of RAW264.7 macrophage was investigated, using LPS alone or in complex with HMGB1 or some recombinant fragments. This study revealed that a N-terminal fragment released by C1s cleavage bears stronger antagonist properties as compared to the A-box, which was not expected. We discuss how this fragment could provide a potent brake for the inflammatory process, opening the way to dampen inflammation.