HMGB1 in health and disease

Investigating the multifaceted role of nucleolin in cellular function and Cancer: Structure, Regulation, and therapeutic implications

Nucleolin (NCL), a highly conserved and multifunctional phosphoprotein, is primarily localized in the nucleolus and participates in various cellular compartments, including the nucleoplasm, cytoplasm, and plasma membrane. Initially discovered in the 1970 s, NCL is integral to ribosome biogenesis through its roles in ribosomal RNA transcription, processing, and assembly. Beyond ribosome synthesis, NCL plays critical roles in cellular processes such as DNA and RNA metabolism, chromatin remodeling, and cell cycle regulation, underscoring its essentiality for cell viability. Structurally, NCL comprises multiple functional domains, which facilitates interaction with various kinases and other proteins. NCL's extensive post-translational modifications influence its localization and function. Importantly, NCL has emerged as a key player in multiple pathologies, particularly cancer, where it contributes to tumor growth, metastasis, and drug resistance. On the cell surface, NCL acts as a co-receptor for growth factors and other ligands, facilitating oncogenic signaling. Additionally, its regulation of non-coding RNAs, stabilization of oncogenic mRNAs, and involvement in immune evasion highlight its potential as a therapeutic target. This review provides an unexplored in-depth overview of NCL's structure, functions, and modifications, with a focus on its role in cancer biology and its therapeutic implications.

Potential Impact of Climate Change-Induced Alterations on Pyroptotic Cell Death in Animal Cells: A Review

Climate change-induced alterations in temperature variation, ozone exposure, water salinity and acidification, and hypoxia might influence immunity and thus survival in diverse groups of animals from fish to mammals. Pyroptosis is a type of lytic pro-inflammatory programmed cell death, which participates in the innate immune response, and is involved in multiple diseases characterized by inflammation and cell death, mostly studied in human cells. Diverse extrinsic factors can induce pyroptosis, leading to the extracellular release of pro-inflammatory molecules such as IL-18. Climate change-related factors, either directly or indirectly, can also promote animal cell death via different regulated mechanisms, impacting organismal fitness. However, pyroptosis has been relatively less studied in this context compared to another cell death process, apoptosis. This review covers previous research pointing to the potential impact of climate change, through various abiotic stressors, on pyroptotic cell death in different animal cells in various contexts. It was proposed that temperature, ozone exposure, water salinity, water acidification and hypoxia have the potential to induce pyroptotic cell death in animal cells and promote inflammation, and that these pyroptotic events should be better understood to be able to mitigate the adverse effects of climate change on animal physiology and health. This is of high importance considering the increasing frequency, intensity and duration of climate-based changes in these environmental parameters, and the critical function of pyroptosis in immune responses of animals and in their predisposition to multiple diseases including cancer. Furthermore, the need for further mechanistic studies showing the more direct impact of climate change-induced environmental alterations on pyroptotic cell death in animals at the organismal level was highlighted. A complete picture of the association between climate change and pyroptosis in animals will be also highly valuable in terms of ecological and clinical applications, and it requires an interdisciplinary approach. SIGNIFICANCE: Climate change-induced alterations might influence animal physiology. Pyroptosis is a form of cell death with pro-inflammatory characteristics. Previous research suggests that temperature variation, ozone exposure, water salinity and acidification, and hypoxia might have the potential to contribute to pyroptotic cell death in certain cell types and contexts. Climate change-induced pyroptotic cell death should be better understood to be able to mitigate the adverse effects of climate change on animal health.

Nicotinamide mononucleotide promotes female germline stem cell proliferation by activating the H4K16ac-Hmgb1-Fyn-PLD signaling pathway through epigenetic remodeling

BACKGROUND

Nicotinamide mononucleotide (NMN), an endogenous nucleotide essential for various physiological processes, has an unclear role and regulatory mechanisms in female germline stem cell (FGSC) development.

RESULTS

We demonstrate that NMN significantly enhances FGSC viability and proliferation. Quantitative acetylation proteomics revealed that NMN markedly increases the acetylation of histone H4 at lysine 16 (H4K16ac). Subsequent chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) identified high mobility group box 1 (Hmgb1) as a downstream target of H4K16ac, a finding further validated by ChIP-qPCR. Knockdown of Hmgb1 reduced FGSC proliferation by disrupting cell cycle progression, inducing apoptosis, and decreasing chromatin accessibility. High-throughput chromosome conformation capture (Hi-C) analysis showed that Hmgb1 knockdown induced A/B compartment switching, increased the number of topologically associating domains (TADs), and decreased chromatin loop formation in FGSCs. Notably, the chromatin loop at the promoter region of Fyn proto-oncogene (Fyn) disappeared following Hmgb1 knockdown. ChIP-qPCR and dual-luciferase reporter assays further confirmed the interaction between Hmgb1 and the Fyn promoter. Importantly, Fyn overexpression reversed the inhibitory effects of Hmgb1 knockdown on FGSC proliferation. Proteomic analysis suggested this rescue was mediated through the phospholipase D (PLD) signaling pathway, as Fyn overexpression selectively enhanced the phosphorylation of PLD1 at threonine 147 without affecting serine 561. Furthermore, treatment with 5-fluoro-2-indolyldechlorohaloamide, a PLD inhibitor, nullified the pro-proliferative effects of Fyn overexpression.

CONCLUSIONS

Our findings reveal that NMN promotes FGSC proliferation by activating the H4K16ac-Hmgb1-Fyn-PLD signaling pathway through epigenetic remodeling. These results deepen our understanding of FGSC proliferation and highlight potential therapeutic avenues for advancing FGSC applications in reproductive medicine.

Sepsis and post-sepsis syndrome: a multisystem challenge requiring comprehensive care and management-a review

Sepsis, a medical emergency with high mortality rates, demands comprehensive care spanning from early identification to patient rehabilitation. The sepsis survival chain encompasses early recognition, severity assessment, activation of emergency services, initial antimicrobial therapy, hemodynamic stabilization, and integrated rehabilitation. These interconnected steps are critical to reducing morbidity and mortality. Despite advancements in international guidelines, adherence remains limited, contributing to a significant disease burden. Beyond its acute phase, post-sepsis syndrome (PSS) is characterized by long-term immune dysregulation, chronic inflammation, and metabolic dysfunction, predisposing survivors to recurrent infections, cardiovascular disease, and neurocognitive decline. Mitochondrial dysfunction and epigenetic modifications play a central role in prolonged immunosuppression, impairing adaptive and innate immune responses. Sepsis-induced organ dysfunction impacts multiple systems, including the brain, heart, and kidneys. In the brain, it is associated with neuroinflammation, blood-brain barrier dysfunction, and the accumulation of neurotoxic proteins, leading to acute and chronic cognitive impairment. Myocardial dysfunction involves inflammatory mediators such as TNF-α and IL-6, while sepsis-associated acute kidney injury (SA-AKI) arises from hypoperfusion and inflammation, heightening the risk of progression to chronic kidney disease. Additionally, immune alterations such as neutrophil dysfunction, continuous platelet activation, and suppressed antitumoral responses contribute to increased infection risk and long-term complications. Timely and targeted interventions, including antimicrobial therapy, cytokine modulation, immune restoration, metabolic support, and structured rehabilitation strategies, are pivotal for improving outcomes. However, financial and infrastructural limitations in low-resource settings pose significant barriers to effective sepsis management. Precision medicine, AI-driven early warning systems, and optimized referral networks can enhance early detection and personalized treatments. Promoting public and professional awareness of sepsis, strengthening multidisciplinary post-sepsis care, and integrating long-term follow-up programs are imperative priorities for reducing mortality and improving the quality of life in sepsis survivors.

HMGB1: Different secretion pathways with pivotal role in epilepsy and major depressive disorder

High-mobility group box 1 (HMGB1) protein is a highly prevalent protein that, once it is translocated to an extracellular site, can contribute to the pathogenesis of autoimmune and inflammatory responses, including epilepsy and depression. The conditions needed for release are associated with the production of multiple isoforms, and this translocation may occur in response to both immune cell activation and cell death. HMGB1 has been shown to interact with different mediators, including exportin 1, notch receptors, mitogen-activated protein kinase, STAT, tumor protein 53, and inflammasomes. Furthermore, as a crucial inflammatory mediator, HMGB1 has demonstrated upregulated expression and a higher percentage of translocation from the nucleus to the cytoplasm, acting on downstream receptors such as toll-like receptor 4 and receptor for advanced glycation end products, thereby activating interleukin-1 beta and nuclear factor kappa-B, intensifying inflammatory responses. In this review, we aim to discuss the different molecular interactions for the secretion of HMGB1 along with its pivotal role in epilepsy and major depressive disorder.

Natural compounds and programmed necrosis: pioneering a new frontier in cancer treatments

Programmed necrosis, a controlled cell death method that bypasses resistance mechanisms that render apoptosis ineffective, is a potential cancer treatment target. Due to their diverse biological activities and low side effects, natural products are being explored as modulators of programmed necrosis pathways. This review highlights the potential of natural compounds to target cancer cells while preserving healthy tissues and their interaction with essential programmed necrosis mechanisms like ferroptosis and necroptosis. Recent developments have identified various types of programmable necrosis, including necroptosis, ferroptosis, pyroptosis, proptosis, mitochondrial permeability transition-driven necrosis, and oncosis. Natural compounds are increasingly being utilized as a primary source of anti-cancer medications, providing new cancer treatments. This review demonstrates the molecular mechanisms behind lipid peroxidation, mixed lineage kinase domain-like protein, and receptor-interacting protein kinases (RIPK1 and RIPK3) inducing cell death. Recent research has identified natural compounds like polyphenols, alkaloids, and terpenoids that can modulate pathways and benefit preclinical cancer models. The review underscores the potential of natural compounds in developing innovative cancer treatments by integrating pharmacology and cellular signaling knowledge. Integrating natural compound studies and programmed necrosis research presents a promising avenue for oncologists to overcome treatment resistance. Natural compounds have shown potential in developing programmed necrosis as a novel cancer treatment approach, enhancing therapeutic effectiveness and minimizing side effects through preclinical research, pharmacology, and molecular biology.

4-Hydroxyderricin attenuates ischemic brain injury and neuroinflammation by upregulating haptoglobin expression in microglia

BACKGROUND

Angelica keiskei (Miq.) Koidz. is a traditional plant that is widely used in Asian countries because of its tonic, diuretic, and galactagogue properties. The chalcone compound 4-hydroxyderricin (4-HD), uniquely present in A. keiskei, has demonstrated inhibitory effects on inflammation in peripheral tissues. Nonetheless, its efficacy in central neuroinflammation and ischemic brain injury remains unclear.

PURPOSE

This study aims to assess the ability of 4-HD to alleviate acute ischemic brain injury and the associated inflammatory response, and to elucidate the underlying mechanisms.

METHODS

Mice underwent middle cerebral artery occlusion (MCAO) surgery to induce acute cerebral ischemic injury. The extent of brain injury was evaluated by TTC staining and neurological function scoring. Immunofluorescence was employed to observe glial cell activation, whereas ELISA and RT-PCR were used to quantify inflammatory cytokine expression in ischemic brain tissues. Oxygen-glucose deprivation (OGD) and lipopolysaccharide (LPS) stimulation of BV2 microglial cells were conducted in vitro to examine the direct impact of 4-HD on microglial inflammation. ELISA and RT-PCR were carried out to quantify inflammatory cytokine expression in BV2 cells. Western blotting and immunofluorescence techniques were used to detect protein expression and localization, respectively. Additionally, alterations in gene expression were measured using RNA-seq analysis profiling following 4-HD treatment of BV2 cells. A short hairpin RNA (shRNA) was used to silence the Haptoglobin (Hp) gene to elucidate the relationship between drug effects and Hp protein levels.

RESULTS

4-HD effectively reduced the infarct area and enhanced neurological function 24 h post-MCAO surgery by lowering inflammatory cytokine levels and inhibiting microglia activation in ischemic brain tissues. In OGD and LPS-stimulated BV2 microglia, 4-HD decreased the levels of inflammatory cytokines. Mechanistic research indicated that 4-HD enhanced Hp and reduced HMGB1 expression in BV2 cells. Moreover, the activation of the NF-κB and MAPK signaling pathways, two key pro-inflammatory pathways downstream of HMGB1, was inhibited by 4-HD treatment. In BV2 cells with Hp gene knockdown, the inhibitory effect of HMGB1 disappeared, and its anti-inflammatory effect was also significantly weakened.

CONCLUSION

4-HD has the potential to mitigate brain injury and neuroinflammation resulting from MCAO-induced acute ischemic damage. This neuroprotective effect is linked to the suppression of microglial activation and the inhibition of HMGB1 pro-inflammatory signaling, facilitated by the increased expression of the Hp protein. This study revealed, for the first time, the protective effects and mechanisms of 4-HD on ischemic brain injury. Additionally, we present the Hp protein as a new target for a small-molecule compound to protect against ischemic brain injury, offering a novel strategy for developing new neuroprotective drugs.

Beyond the Toll-Like Receptor 4. Structure-Dependent Lipopolysaccharide Recognition Systems: How far are we?

With an enormous potential in immunology and vaccinology, lipopolysaccharides (LPSs) are among the most extensively studied bacteria-derived molecules. LPS centered studies are countless, and their results reverberate in all areas of the life sciences, including chemistry, biology, genetics, biophysics, and medicine. Most of these research activities are focused on the LPS-induced immune response activation by means of Myeloid Differentiation protein-2/Toll Like Receptor 4 (MD-2/TLR4) complex, which currently is the most largely explored LPS sensing pathway. However, the enormous structural variability of LPS allows interactions with numerous other receptors involved in a wide range of equally important immunological scenarios. In this review, we explore these additional LPS recognition systems, which operate within interconnected signaling cascades, highlighting their role in maintaining physiological homeostasis and their involvement in the development of severe human diseases. Understanding these pathways, their interconnections, and the crosstalk between them and TLR4/MD-2 is essential for guiding the development of pharmacologically active molecules that could specifically modulate the inflammatory response, paving the way to new strategies for combating immune-mediated diseases and resistant infections.

The prospect and underlying mechanisms of Chinese medicine in treating periodontitis

Inflammation represents a critical immune response triggered by cellular activities and inflammatory mediators following tissue damage. It plays a central role in the pathological progression of diverse diseases, including psychiatric disorders, cancer, and immunological conditions, rendering it an essential target for therapeutic intervention. Periodontitis, a prevalent oral inflammatory disease, is a leading cause of tooth loss and poses significant health challenges globally. Traditionally, inflammatory diseases such as periodontitis have been treated with systemic administration of synthetic chemicals. However, recent years have witnessed challenges, including drug resistance and microbial dysbiosis associated with these treatments. In contrast, natural products derived from Chinese medicine offer numerous benefits, such as high safety profiles, minimal side effects, innovative pharmacological mechanisms, ease of extraction, and multiple targets, rendering them viable alternatives to conventional antibiotics for treating inflammatory conditions. Numerous effective anti-inflammatory natural products have been identified in traditional Chinese medicine (TCM), including alkaloids, flavonoids, terpenoids, lignans, and other natural products that exhibit inhibitory effects on inflammation and are potential therapeutic agents. Several studies have confirmed the substantial anti-inflammatory and immunomodulatory properties of these compounds. This comprehensive review examines the literature on the anti-inflammatory effects of TCM-derived natural products from databases such as PubMed, Web of Science, and CNKI, focusing on terms like "inflammation", "periodontitis", "pharmacology", and "traditional Chinese medicine". The analysis systematically summarizes the molecular pharmacology, chemical composition, and biological activities of these compounds in inflammatory responses, alongside their mechanisms of action. This research seeks to deepen understanding of the mechanisms and biological activities of herbal extracts in managing inflammatory diseases, potentially leading to the development of promising new anti-inflammatory drug candidates. Future applications could extend to the treatment of various inflammatory conditions, including periodontitis.

Identifying G-quadruplex-interacting proteins in cancer-related gene promoters

G-quadruplexes (G4s) are noncanonical DNA or RNA secondary structures involved in numerous biological processes. Their recognition by G4-related proteins (G4RPs) is essential for modulating biological pathways, particularly those associated with transcription and cancer progression. Identifying G4RPs is crucial for understanding their role in diseases like cancer, as these proteins may represent promising therapeutic targets. In this study, a proteomic-based fishing-for-partners approach was employed to identify putative interactors of G4-forming DNA sequences from the promoter regions of cancer-related genes DAP, HIF-1α, JAZF-1, and PDGF-A. A total of eighty-six G4RPs were identified, including nineteen known RNA and/or DNA G4 interactors. Notably, fourteen proteins were identified as potential interactors of all four investigated G4-forming DNA, seven of which were novel G4RPs. Direct interactions with G4s were validated for five of these proteins (AHNAK, GAPDH, HNRNP M, LMNA, and PPIA) using surface plasmon resonance experiments, which showed nanomolar binding affinities. This study not only validated known G4RPs but also led to the discovery of new G4/protein interactions, providing the basis for further investigation into their biological significance and potential implications in disease-associated pathways.

NINJ1-mediated plasma membrane rupture of pyroptotic endothelial cells exacerbates blood-brain barrier destruction caused by neutrophil extracellular traps in traumatic brain injury

Brain endothelial cell (bEC) dysfunction is the main factor of blood-brain barrier (BBB) breakdown, which triggers a vicious cycle of aggravating traumatic brain injury (TBI) pathogenesis. Previous studies have revealed that neutrophil extracellular traps (NETs) released by neutrophils can lead to BBB disruption, but there is a lack of research on the underlying mechanisms after TBI. Here, excessive NETs were found in both contused brain tissue and circulation following TBI. We found that NETs could activate the TLR4/NF-κB pathway to induce bEC pyroptosis, which led to BBB disruption after TBI. During this process, ninjurin-1 (NINJ1) was activated in pyroptotic bECs, and it mediated the release of high mobility group box 1 protein (HMGB1) via plasma membrane rupture (PMR) to promote NET formation. NINJ1-mediated release of HMGB1 aggravated NET accumulation by forming a vicious circle following TBI. Knockdown of NINJ1 rescued NET formation, attenuated BBB leakage, and improved neurological outcomes after TBI. NINJ1 may represent a promising target for alleviating NET-induced BBB destruction and other related injuries after TBI.

Efferocytosis and inflammation: a bibliometric and systematic analysis

Objective

To visualize and analyze the trends and hotspots of efferocytosis and inflammation via bibliometric methods.

Methods

Relevant articles and reviews from 2006 to 2023 were retrieved from the Web of Science Core Collection. The data were processed with CiteSpace, and some graphs were generated with Microsoft Excel (version 2016), VOSviewer, Scimago Graphica, Bibliometrix and R Studio.

Results

A total of 1,003 papers were included, revealing a significant upward trend in efferocytosis and inflammation research. The United States (456, 45.46%), China (164, 16.35%) and the United Kingdom (99, 9.87%) were the three countries with the highest numbers of publications. Harvard University (84, 6.74%) contributes the most out of the top 5 institutions. Among the researchers in this field, Serhan CN was the author with the highest number of articles in the field (35, 3.49%), and deCathelineau AM first named "efferocytosis" in 2003. Keyword analysis identified "activation," "tam receptors," "docosahexaenoic acid" "systemic lupus erythematosus," "myocardial infarction" and "alveolar macrophages" as core topics, indicating a concentrated trend in the mechanism of physiological state and inflammatory diseases such as autoimmune, cardiovascular, and pulmonary diseases. The latest surge words "inflammation resolution" and "cancer" in the keyword heatmap indicate future research directions.

Conclusion

Research on the association between efferocytosis and inflammation has been a promising field. Key areas of focus include the crucial role of efferocytosis on tissue homeostasis and the pathogenesis of nontumorous inflammatory diseases. Future research will likely continue to explore these frontiers, with an emphasis on understanding efferocytosis in the context of chronic diseases and cancer, as well as developing novel therapeutic strategies.

HMGB1 induces unexplained recurrent spontaneous abortion by mediating decidual macrophage autophagy

BACKGROUND

The overexpression of HMGB1 at the maternal-fetal interface (MFI) is recognized as a significant factor in Unexplained Recurrent Spontaneous Abortion (URSA). This study aimed to investigate autophagy in the decidual tissues of URSA patients and to explore the relationship between HMGB1 and macrophage autophagy at the MFI in URSA.

METHODS

Human decidual tissues were collected from 40 patients diagnosed with URSA and from 60 women undergoing active termination of pregnancy. Mouse models of pregnancy loss URSA and in vitro cellular models were created and then subjected to treatment with an HMGB1 inhibitor (aspirin) and an anti-HMGB1 antibody, respectively. Autophagy at the MFI was evaluated using western blot analysis, immunofluorescence assays, and transmission electron microscopy (TEM).

RESULTS

This study revealed a high expression of LC3B and a low expression of P62 in the decidual tissue of the URSA group. These findings were further corroborated through TEM. The localization of autophagy within macrophages indicated a significant enhancement of autophagy in the decidual macrophages of the URSA group. However, treatment with low-dose aspirin resulted in a reversal of protein expression and a reduction in autophagy. In in vitro experiments, recombinant HMGB1 was found to mediate autophagy of immortalized bone marrow-derived macrophages, which could be inhibited by an anti-HMGB1 antibody.

CONCLUSION

This study first indicates that elevated levels of HMGB1 at the MFI trigger autophagy in macrophages, thereby promoting aseptic inflammation and contributing to the onset and progression of URSA. Furthermore, low-dose aspirin has been demonstrated to protect against URSA by inhibiting HMGB1, which in turn suppresses autophagy production.

HMGB1: key mediator in digestive system diseases

High Mobility Group Box 1 (HMGB1), a multifunctional non-histone protein, and its involvement in various physiological and pathological contexts has garnered significant attention. Given HMGB1's central function in modulating key biological activities, such as inflammatory responses and cellular death, its contribution to the pathogenesis of digestive system diseases has become a focus of growing interest. This review aims to comprehensively explore the mechanisms by which HMGB1 contributes to the progression of inflammatory bowel disease (IBD), liver disorders, and pancreatitis. Furthermore, we explore the prospective clinical applications and outline future research directions for HMGB1 in digestive diseases, providing fresh perspectives that highlight the necessity of ongoing studies to understand its role in these conditions.

Pathophysiological role of high mobility group box-1 signaling in neurodegenerative diseases

Nucleocytoplasmic translocation of HMGB1 (high mobility group box-1) plays a significant role in disease progression. Several methods contribute to the translocation of HMGB1 from the nucleus to the cytoplasm, including inflammasome activation, TNF-α signaling, CRM1-mediated transport, reactive oxygen species (ROS), JAK/STAT pathway, RIP3-mediated p53 involvement, XPO-1-mediated transport, and calcium-dependent mechanisms. Due to its diverse functions at various subcellular locations, HMGB1 has been identified as a crucial factor in several Central Nervous System (CNS) disorders, including Huntington's disease (HD), Parkinson's disease (PD), and Alzheimer's disease (AD). HMGB1 displays a wide array of roles in the extracellular environment as it interacts with several receptors, including CXCR4, TLR2, TLR4, TLR8, and RAGE, by engaging in these connections, HMGB1 can effectively regulate subsequent signaling pathways, hence exerting an impact on the progression of brain disorders through neuroinflammation. Therefore, focusing on treating neuroinflammation could offer a common therapeutic strategy for several disorders. The objective of the current literature is to demonstrate the pathological role of HMGB1 in various neurological disorders. This review also offers insights into numerous therapeutic targets that promise to advance multiple treatments intended to alleviate brain illnesses.

Targeting high-mobility-group-box-1-mediated inflammation: a promising therapeutic approach for myocardial infarction

Myocardial ischemia, resulting from coronary artery blockage, precipitates cardiac arrhythmias, myocardial structural changes, and heart failure. The pathophysiology of MI is mainly based on inflammation and cell death, which are essential in aggravating myocardial ischemia and reperfusion injury. Emerging research highlights the functionality of high mobility group box-1, a non-histone nucleoprotein functioning as a chromosomal stabilizer and inflammatory mediator. HMGB1's release into the extracellular compartment during ischemia acts as damage-associated molecular pattern, triggering immune reaction by pattern recognition receptors and exacerbating tissue inflammation. Its involvement in signaling pathways like PI3K/Akt, TLR4/NF-κB, and RAGE/HMGB1 underscores its significance in promoting angiogenesis, apoptosis, and reducing inflammation, which is crucial for MI treatment strategies. This review highlights the complex function of HMGB1 in the pathogenesis of myocardial infarction by summarizing novel findings on the protein in ischemic situations. Understanding the mechanisms underlying HMGB1 could widen the way to specific treatments that minimize the severity of MI and enhance patient outcomes.

Tumor Vaccine Exploiting Membranes with Influenza Virus-Induced Immunogenic Cell Death to Decorate Polylactic Coglycolic Acid Nanoparticles

Immunogenic cell death (ICD) of tumor cells, which is characterized by releasing immunostimulatory "find me" and "eat me" signals, expressing proinflammatory cytokines and providing personalized and broad-spectrum tumor antigens draws increasing attention in developing a tumor vaccine. In this study, we aimed to investigate whether the influenza virus (IAV) is efficient enough to induce ICD in tumor cells and an extra modification of IAV components such as hemeagglutinin (HA) will be helpful for the ICD-induced cells to elicit robust antitumor effects; in addition, to evaluate whether the membrane-engineering polylactic coglycolic acid nanoparticles (PLGA NPs) simulating ICD immune stimulation mechanisms hold the potential to be a promising vaccine candidate, a mouse melanoma cell line (B16-F10 cell) was infected with IAV rescued by the reverse genetic system, and the prepared cells and membrane-modified PLGA NPs were used separately to immunize the melanoma-bearing mice. IAV-infected tumor cells exhibit dying status, releasing high mobility group box-1 (HMGB1) and adenosine triphosphate (ATP), and exposing calreticulin (CRT), IAV hemeagglutinin (HA), and tumor antigens like tyrosinase-related protein 2 (TRP2). IAV-induced ICD cells enhance biomass-derived carbon (BMDCs) migration, antigen uptake, cross-presentation, and maturation in vitro. Furthermore, immunization with IAV-induced ICD cells effectively suppressed tumor growth in melanoma-bearing mice. The isolated cell membrane inherited the immunological characteristics from the ICD cells and elicited robust antitumor immune responses through decorating PLGA NPs loading with a tumor-specific helper T-cell peptide and supplemented with ATP in a hydrogel system. This study indicated a promising strategy for developing cell-based and personalized tumor vaccines through fully taking advantage of the immune stimulation mechanisms of ICD occurrence in tumor cells, IAV modification, and nanoscale delivery.

Long Noncoding RNA GAS5 Contributes to Mycoplasma pneumoniae Pneumonia by Regulating NF-κB via miR-29c/HMGB1 Axis

Mycoplasma pneumoniae pneumonia (MPP) poses a major threat to pediatric health. Our previous study suggested that GAS5 level was elevated in the peripheral blood of MPP children. However, the mechanism by which GAS5 regulates lung inflammation Mycoplasma pneumoniae (MP) infection-induced remains unknown. An MPP mouse model was constructed by MP intranasal injection to enrich for alveolar macrophage (AM). Mouse AM was stimulated using lipid-associated membrane proteins (LAMPs) to mimic an in vitro pneumonia model, and transfection was used to achieve specific knockdown or overexpression of target genes. GAS5 level was significantly increased in AM of the MPP mouse model, and significantly and positively related with the mRNA level of HMGB1, but no physical binding between GAS5 and HMGB1 proteins. miR-29c level was significantly decreased in AM of the MPP mouse model and negatively related with the HMGB1. We found the specific binding of GAS5 to miR-29c, and the specific binding of miR-29c to the HMGB1 mRNA 3'UTR. miR-29c mimic and knockdown of HMGB1 both significantly impeded LAMPs-induced apoptosis, IL-6 and TNF-α secretion, and the NF-κB activation. Ectopic expression of GAS5 counteracted the effect of miR-29c mimic, and miR-29c inhibitor counteracted the effect of HMGB1 knockdown. Furthermore, silencing of GAS5 significantly alleviated MPP-induced inflammation and pathological lung injury in the MPP mouse model. GAS5/miR-29c/HMGB1 is highly involved in inflammation and lung histopathological injury in MPP disease progression by regulating the NF-κB signaling pathway.

Deciphering the mechanisms of long non-coding RNAs in ferroptosis: insights into its clinical significance in cancer progression and immunology

A new type of nonapoptotic, iron-dependent cell death induced by lipid peroxidation is known as ferroptosis. Numerous pathological processes, including inflammation and cancer, have been demonstrated to be influenced by changes in the ferroptosis-regulating network. Long non-coding RNAs (LncRNAs) are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that lncRNAs can interfere with the progression of ferroptosis by modulating ferroptosis-related genes directly or indirectly. Despite evidence implicating lncRNAs in cancer and inflammation, studies on their mechanisms and therapeutic potential remain scarce. We investigate the mechanisms of lncRNA-mediated regulation of inflammation and cancer immunity, assessing the feasibility and challenges of lncRNAs as therapeutic targets in these conditions.

Roles of the Receptor for Advanced Glycation End Products and Its Ligands in the Pathogenesis of Alzheimer's Disease

The Receptor for Advanced Glycation End Products (RAGE), part of the immunoglobulin superfamily, plays a significant role in various essential functions under both normal and pathological conditions, especially in the progression of Alzheimer's disease (AD). RAGE engages with several damage-associated molecular patterns (DAMPs), including advanced glycation end products (AGEs), beta-amyloid peptide (Aβ), high mobility group box 1 (HMGB1), and S100 calcium-binding proteins. This interaction impairs the brain's ability to clear Aβ, resulting in increased Aβ accumulation, neuronal injury, and mitochondrial dysfunction. This further promotes inflammatory responses and oxidative stress, ultimately leading to a range of age-related diseases. Given RAGE's significant role in AD, inhibitors that target RAGE and its ligands hold promise as new strategies for treating AD, offering new possibilities for alleviating and treating this serious neurodegenerative disease. This article reviews the various pathogenic mechanisms of AD and summarizes the literature on the interaction between RAGE and its ligands in various AD-related pathological processes, with a particular focus on the evidence and mechanisms by which RAGE interactions with AGEs, HMGB1, Aβ, and S100 proteins induce cognitive impairment in AD. Furthermore, the article discusses the principles of action of RAGE inhibitors and inhibitors targeting RAGE-ligand interactions, along with relevant clinical trials.

Attenuation of Nerve Agent Induced Neurodegenerative and Neuroinflammatory Changes in Rats with New Combination Treatment of Galantamine, Atropine and Midazolam

Acute nerve agent exposure can kill a person within minutes or produce multiple neurotoxic effects and subsequent brain damage with potential long-term adverse outcomes. Recent abuse of nerve-agents on Syrian civilians, during Japan terrorist attacks, and personal assassinations in the UK, and Malaysia indicate their potential threat to world population. Existing nerve agent antidotes offer only incomplete protection especially, if the treatment is delayed. To develop the effective drugs, it is advantageous to elucidate the underlying mechanisms of nerve agent-induced multiple neurological impairments. This study aimed to investigate the molecular basis of neuroinflammation during nerve agent toxicity with focus on inflammasome-associated proteins and neurodegeneration. In rats, NOD-like receptor family pyrin domain containing 3 (NLRP3), and glial fibrillary acidic protein (GFAP) immunoreactivity levels were considerably increased in the hippocampus, piriform cortex, and amygdala areas after single subcutaneous soman exposure (90 µg/kg-1). Western analysis indicated a notable increase in the neuroinflammatory indicator proteins, high mobility group box 1 (HMGB1) and inducible nitric oxide synthase (iNOS) levels. The presence of fluorojade-C-stained degenerating neurons in distinct rat brain areas is indicating the neurodegeneration during nerve agent toxicity. Pre-treatment with galantamine (3 mg/kg, - 30 min) followed by post-treatment of atropine (10 mg/kg, i.m.) and midazolam (5 mg/kg, i.m.), has completely protected animals from death induced by supra-lethal dose of soman (2XLD50) and reduced the neuroinflammatory and neurodegenerative changes. Results highlight that this new prophylactic and therapeutic drug combination might be an effective treatment option for soldiers deployed in conflict areas and first responders dealing with accidental/deliberate release of nerve agents.

Role of the Receptor for Advanced Glycation End Products (RAGE) and Its Ligands in Inflammatory Responses

Since its discovery in 1992, the receptor for advanced glycation end products (RAGE) has emerged as a key receptor in many pathological conditions, especially in inflammatory conditions. RAGE is expressed by most, if not all, immune cells and can be activated by many ligands. One characteristic of RAGE is that its ligands are structurally very diverse and belong to different classes of molecules, making RAGE a promiscuous receptor. Many of RAGE ligands are damaged associated molecular patterns (DAMPs) that are released by cells under inflammatory conditions. Although RAGE has been at the center of a lot of research in the past three decades, a clear understanding of the mechanisms of RAGE activation by its ligands is still missing. In this review, we summarize the current knowledge of the role of RAGE and its ligands in inflammation.

Macrophage activation syndrome in Sepsis: from pathogenesis to clinical management

BACKGROUND

Sepsis represents a significant global health and hygiene challenge. Excessive activation of macrophages in sepsis can result in certain patients displaying characteristics akin to those observed in Macrophage Activation Syndrome (MAS). MAS represents a grave immune system disorder characterized by persistent and severe inflammation within the body. In the context of sepsis, MAS presents atypically, leading some researchers to refer to it as Macrophage Activation-Like Syndrome (MALS). However, there are currently no effective treatment measures for this situation. The purpose of this article is to explore potential treatment methods for sepsis-associated MALS.

OBJECTIVE

The objective of this review is to synthesize the specific pathophysiological mechanisms and treatment strategies of MAS to investigate potential therapeutic approaches for sepsis-associated MALS.

METHOD

We searched major databases (including PubMed, Web of Science, and Google Scholar etc.) for literature encompassing macrophage activation syndrome and sepsis up to Mar 2024 and combined with studies found in the reference lists of the included studies.

CONCLUSION

We have synthesized the underlying pathophysiological mechanism of MALS in sepsis, and then summarized the diagnostic criteria and the effects of various treatment modalities utilized in patients with MAS or MALS. In both scenarios, heterogeneous treatment responses resulting from identical treatment approaches were observed. The determination of whether the patient is genuinely experiencing MALS significantly impacts the ultimate outcomes of therapeutic efficacy. In order to tackle this concern, additional clinical trials and research endeavors are imperative.

Analyzing the role of ferroptosis in ribosome-related bone marrow failure disorders: From pathophysiology to potential pharmacological exploitation

Within the last decade, the scientific community has witnessed the importance of ferroptosis as a novel cascade of molecular events leading to cellular decisions of death distinct from apoptosis and other known forms of cell death. Notably, such non- apoptotic and iron-dependent regulated cell death has been found to be intricately linked to several physiological processes as well as to the pathogenesis of various diseases. To this end, recent data support the notion that a potential molecular connection between ferroptosis and inherited bone marrow failure (IBMF) in individuals with ribosomopathies may exist. In this review, we suggest that in ribosome-related IBMFs the identified mutations in ribosomal proteins lead to changes in the ribosome composition of the hematopoietic progenitors, changes that seem to affect ribosomal function, thus enhancing the expression of some mRNAs subgroups while reducing the expression of others. These events lead to an imbalance inside the cell as some molecular pathways are promoted while others are inhibited. This disturbance is accompanied by ROS production and lipid peroxidation, while an additional finding in most of them is iron accumulation. Once lipid peroxidation and iron accumulation are the two main characteristics of ferroptosis, it is possible that this mechanism plays a key role in the manifestation of IBMF in this type of disease. If this molecular mechanism is further confirmed, new pharmacological targets such as ferroptosis inhibitors that are already exploited for the treatment of other diseases, could be utilized to improve the treatment of ribosomopathies.

A pan-cancer analysis of the oncogenic function of HMGB1 in human tumors

Background

Although high mobility group box protein 1 (HMGB1) has been researched in relation to cancer in many investigations, a thorough investigation of its role in pan-cancer has yet to be conducted. With the objective of bridging this gap, we delved into the functions of HMGB1 in various tumors.

Methods

This investigation employed The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases to examine HMGB1 gene expression differences and correlation with survival across various human tumors. Then, genetic alterations of HMGB1 were analyzed by tool cBioPortal, and immune cell infiltration was assessed. Finally, we gathered clinial samples from 95 patients with various types of solid tumor and performed somatic mutation analysis using panel sequencing. This further highlighted the role of HMGB1 in different solid tumors.

Results

There was a notable elevation of HMGB1 gene expression in tumor tissues as opposed to non-cancerous tissues across the bulk of tumor types. Elevated HMGB1 gene expression had a connection with shorter overall survival, progression-free survival, and disease-free survival in specific tumor types. Genetic alterations of HMGB1 suggested that the amplifications and mutations of HMGB1 may impact the prognosis of breast cancer (BRCA) and liver hepatocellular carcinoma (LIHC). Both BRCA and mesothelioma (MESO) displayed a connection between the infiltration of cancer-associated fibroblasts (CAFs) and HMGB1 gene expression. Moreover, HMGB1 co-expression analysis revealed its association with genes involved in RNA splicing, mRNA processing, and modulation of mRNA metabolic processes. Additionally, a pathway analysis by use of the Kyoto Encyclopedia of Genes and Genomes (KEGG) unveiled that HMGB1 was implicated in the pathogenic mechanisms of "Hepatitis B," "Viral Carcinogenesis," and "Hepatocellular Carcinoma." Based on somatic mutation analysis of 95 patients with different solid tumors, we found that the frequency of HMGB1 mutations was higher in Liver cancer patients compared to other solid tumors. This finding is consistent with our in-silico study results. Additionally, we discovered that the frequency of HMGB1 mutations ranked among the top 20 mutated genes in the 95 patients' data, indicating that HMGB1 plays an important role in the development and prognosis of various solid tumors.

Conclusion

This pan-cancer study of HMGB1 underscores its potential as a signature marker and target for the management of various tumor types.

High Mobility Group Box 1 (HMGB1): Molecular Signaling and Potential Therapeutic Strategies

High Mobility Group Box 1 (HMGB1) is a highly conserved non-histone chromatin-associated protein across species, primarily recognized for its regulatory impact on vital cellular processes, like autophagy, cell survival, and apoptosis. HMGB1 exhibits dual functionality based on its localization: both as a non-histone protein in the nucleus and as an inducer of inflammatory cytokines upon extracellular release. Pathophysiological insights reveal that HMGB1 plays a significant role in the onset and progression of a vast array of diseases, viz., atherosclerosis, kidney damage, cancer, and neurodegeneration. However, a clear mechanistic understanding of HMGB1 release, translocation, and associated signaling cascades in mediating such physiological dysfunctions remains obscure. This review presents a detailed outline of HMGB1 structure-function relationship and its regulatory role in disease onset and progression from a signaling perspective. This review also presents an insight into the status of HMGB1 druggability, potential limitations in understanding HMGB1 pathophysiology, and future perspective of studies that can be undertaken to address the existing scientific gap. Based on existing paradigm of various studies, HMGB1 is a critical regulator of inflammatory cascades and drives the onset and progression of a broad spectrum of dysfunctions. Studies focusing on HMGB1 druggability have enabled the development of biologics with potential clinical benefits. However, deeper understanding of post-translational modifications, redox states, translocation mechanisms, and mitochondrial interactions can potentially enable the development of better courses of therapy against HMGB1-mediated physiological dysfunctions.

May high mobility group box protein-1 be a biomarker for major depressive disorder?

High Mobility Group Box Protein-1 (HMGB1), which has proinflammatory properties, is known to be involved in psychiatric disorders as far as we know, there are only one clinical studies investigating the role of HMGB1 in major depressive disorder (MDD). In this study, we aimed to investigate the role of HMGB1 in the etiopathogenesis of MDD and whether HMGB1 can be used as a biomarker in MDD by measuring the serum HMGB1 levels of depressed patients in the episode and remission periods. This study included 30 patients diagnosed with MDD in episode, 30 patients in remission and 30 healthy controls. Each group comprised 20 female and 10 male participants. In this study, serum HMGB1 levels were found to be lower in the patient group in the episode compared to the patient group in the remission period and the healthy control group. There was no significant difference between the patient group in remission and the healthy control group in terms of serum HMGB1 levels. The fact that serum HMGB1 levels were lower in the patient group in the episode compared to the patient group in the remission period and the control group may be related to the neuroprotective effects of HMGB1. HMGB1 may be used as a biomarker for MDD.

PCSK9 and its relationship with HMGB1, TLR4, and TNFα in non-statin and statin-treated coronary artery disease patients

Despite statin use in coronary artery disease (CAD), significant risk remains, potentially due to increased proprotein convertase subtilisin/kexin-type 9 (PCSK9) production, which raises LDL-C levels and induces inflammation. The exact relationship between PCSK9, inflammatory markers like TNFα, TLR4, CRP, and HMGB1, and monocyte subsets is poorly understood. This study aimed to explore these relationships in non-statin and statin-taking CAD patients. This case-control study included 91 controls and 91 stable CAD patients, divided into no-statin (NS, n = 25), low-dose statin (LDS, n = 25), and high-dose statin (HDS, n = 41) groups. Serum levels of LDL-C, CRP, PCSK9, TLR4, HMGB1, and TNFα were measured. Monocyte subsets were classified using flow cytometry into classical monocytes (CM), intermediate monocytes (IM), and non-classical monocytes (NCM). CAD patients showed elevated PCSK9, LDL-C, and inflammatory markers compared to controls. Statin groups (LDS, HDS) had lower LDL-C and inflammatory markers but higher PCSK9 than the NS group, with the HDS group showing the lowest LDL-C and inflammatory markers but the highest PCSK9. In the NS group, PCSK9 positively correlated with inflammatory markers (HMGB1, TNFα, TLR4, CRP) and monocyte subsets (IM%, NCM%). In the total statin group (LDS + HDS), PCSK9 negatively correlated with HMGB1, TLR4, and NCM%, for each, respectively, and positively with CM%. Multivariable linear regression showed significant associations between PCSK9 and HMGB1, NCM%, and IM% in the NS group, and HMGB1, NCM%, and TLR4 in the total statin group. In conclusion, we recommend combining PCSK9 inhibitors with statins in high-risk CAD patients. This may enhance statin efficacy, reduce LDL-C, and inhibit the TLR4/NF-кB inflammatory pathway, decreasing atherosclerotic inflammation.

Glucocorticoids induce HMGB1 release in primary cultured rat cortical microglia

Stress, a risk factor for major depressive disorder and Alzheimer disease, leads to the release of high-mobility group box-1 (HMGB1) protein, which in turn causes neuroinflammation. The mechanism underlying stress-induced HMGB1 release is unknown, but stress-associated glucocorticoids could be involved. Primary cultured rat cortical microglia and neurons were treated with corticosterone, a stress-associated glucocorticoid, and HMGB1 release was measured by ELISA and western blotting to test this hypothesis. With corticosterone treatment, significant HMGB1 was released in microglia but not in neuronal cell cultures. HMGB1 mRNA expression and HMGB1 protein expression in microglia were not affected by corticosterone treatment. Thus, the source of extracellular HMGB1 released into the medium is likely to be existing nuclear HMGB1 rather than newly synthesized HMGB1. Corticosterone-induced HMGB1 release in microglia culture was significantly attenuated by blocking glucocorticoid receptors but not mineralocorticoid receptors. Dexamethasone, a selective glucocorticoid receptor agonist, and dexamethasone-bovine serum albumin (BSA), a membrane-impermeable glucocorticoid receptor agonist used to confirm the membrane receptor-mediated effects of glucocorticoids, increased the release of HMGB1. Immunocytochemistry showed that HMGB1 translocated from the nucleus to the cytoplasm following dexamethasone or dexamethasone-BSA treatment through glucocorticoid receptors. The present findings suggest that glucocorticoids stimulate microglial membrane glucocorticoid receptors and trigger cytoplasmic translocation and extracellular release of nuclear HMGB1. Thus, under stress conditions, glucocorticoids induce microglial HMGB1 release, leading to a neuroinflammatory state that could mediate neurological disorders.

A personalized vaccine combining immunogenic cell death-induced cells and nanosized antigens for enhanced antitumor immunity

The tumor vaccine aims to activate the immune system, promote antitumor cellular responses, and restore immune recognition and clearance of tumor cells. However, the low immunogenicity and heterogeneity of tumor antigens, along with immunosuppressive mechanisms, severely hinder tumor vaccines from achieving an efficient and sustained antitumor effect. Herein, we developed a combined vaccine strategy that utilizes immunogenic cell death (ICD) to elicit a broad spectrum of antigen-specific responses in a whole-cell-based manner. Additionally, we introduced nanosized antigens to intensify immune responses targeting a key tumor antigen. The combination of mitoxantrone (MTX) and curcumin (Cur) optimized ICD properties in TC-1 tumor cells, as evidenced by increased release of "find me" signals, such as HMGB1 and ATP, and enhanced exposure of the "eat me" signal, CALR, compared to either MTX or Cur alone. Correspondingly, the ICD cells induced by the combination produced more significant antitumor effects in vivo. Furthermore, the ICD cells in combination with E7-HBcAg VLPs or E7-Q11 nanofibers induced more intense effector cell responses to the antigen included in the nanovaccines, as well as a broad spectrum of antigens provided by tumor cells, and significantly suppressed the growth of established tumors compared with either ICD cells, VLPs, or nanofibers alone. In conclusion, the combination of ICD cells and nanosized antigens produced synergistic antitumor effects and elicited robust and comprehensive antitumor immunity, presenting an attractive strategy for developing personalized tumor vaccines.

Ginsenoside Rk3 Treats Corneal Injury Through the HMGB1/TLR4/NF-κB Pathway

The cornea serves as a vital protective shield for the eye, safeguarding its intricate internal structures from external threats. Damage to the cornea compromises this protective function, triggering inflammation and potentially causing long-term harm. While ginsenoside Rk3 has demonstrated potential for repairing the corneal barrier and reducing inflammation, its effectiveness in treating corneal damage remains relatively unexplored. This comprehensive study uses both in vivo and in vitro models to investigate the therapeutic capabilities of ginsenoside Rk3. Using two models of corneal damage, a benzalkonium chloride-induced mouse model and a high osmolarity-induced human corneal epithelial cell model, we scrutinized the effects of ginsenoside Rk3 treatment. Our results showed that ginsenoside Rk3-treated mice manifested reduced corneal damage and inflammation compared with their untreated counterparts. Furthermore, mice treated with ginsenoside Rk3 exhibited an organized arrangement of corneal cells and diminished stromal layer thickness, indicating reparative properties of ginsenoside Rk3. Additionally, ginsenoside Rk3 increased the expression of tight junction proteins, suppressed inflammatory factors, and decreased HMGB1 protein expression, thereby modulating downstream signaling pathways. Collectively, our findings present compelling evidence that ginsenoside Rk3 is a promising therapeutic option for corneal injury. By repairing the corneal barrier, mitigating inflammation, and modulating specific protein levels, ginsenoside Rk3 opens new avenues for managing corneal damage.

Causal effect of immune cells on idiopathic pulmonary fibrosis: A mendelian randomization study

BACKGROUND

A key component of idiopathic pulmonary fibrosis (IPF) is the involvement of immune cells. However, the causal interaction between different immune cell signatures and IPF remain inconclusive.

OBJECTIVES

Based on publicly accessible data, our study utilized the Mendelian randomization (MR) approach to determine the causative relevance of complex immune cell phenotypes in IPF.

METHODS

We deployed a two-sample Mendelian randomization approach to evaluate the causal interaction between immune cell markers and IPF. All data regarding 731 immune signatures and IPF were acquired from two genome-wide association studies (GWAS) that are accessible to the public. The original study adopted the inverse variance weighted (IVW) method, followed by sensitivity analyses aimed at eliminating heterogeneity and pleiotropy. Additionally, Multivariate Mendelian randomization (MVMR) was utilized to identify the independent risk factors in our study.

RESULTS

The summary dataset for IPF was accessed from the Finnish Genetic Consortium R9, comprising 2018 patients and 373,064 controls. And the dataset for immune signatures was conducted in 3,757 Sardinian individuals. By conducting IVW and extensive sensitivity analyses, univariate Mendelian randomization (UVMR) identified one immunophenotype that remained causally associated with IPF after false discovery rate (FDR) correction: CD39 on CD39+ CD8+T cells (odd ratio [OR] = 0.850, 95 % confidence interval [CI] = 0.787-0.918, P = 3.68 × 10-5). The causal association with IPF was further validated using MVMR.

CONCLUSIONS

Based on rigorous MR analysis methods and FDR correction, our study demonstrated that CD39 on CD39+ CD8+T cells showed a protective effect against IPF, providing effective insights for preventing and diagnosing pulmonary fibrosis.

High Mobility Group Box 1 and Cardiovascular Diseases: Study of Act and Connect

Cardiovascular disease is the deadly disease that can result in sudden death, and inflammation plays an important role in its onset and progression. High mobility group box 1 (HMGB1) is a nuclear protein that regulates transcription, DNA replication, repair, and nucleosome assembly. HMGB1 is released passively by necrotic tissues and actively secreted by stressed cells. Extracellular HMGB1 functions as a damage associated molecular patterns molecule, producing numerous redox forms that induce a range of cellular responses by binding to distinct receptors and interactors, including tissue inflammation and regeneration. Extracellular HMGB1 inhibition reduces inflammation and is protective in experimental models of myocardial ischemia/reperfusion damage, myocarditis, cardiomyopathies caused by mechanical stress, diabetes, bacterial infection, or chemotherapeutic drugs. HMGB1 administration following a myocardial infarction followed by permanent coronary artery ligation improves cardiac function by stimulating tissue regeneration. HMGB1 inhibits contractility and produces hypertrophy and death in cardiomyocytes, while also stimulating cardiac fibroblast activity and promoting cardiac stem cell proliferation and differentiation. Maintaining normal nuclear HMGB1 levels, interestingly, protects cardiomyocytes from apoptosis by limiting DNA oxidative stress, and mice with HMGB1cardiomyocyte-specific overexpression are partially protected from cardiac injury. Finally, elevated levels of circulating HMGB1 have been linked to human heart disease. As a result, following cardiac damage, HMGB1 elicits both detrimental and helpful responses, which may be due to the formation and stability of the various redox forms, the particular activities of which in this context are mostly unknown. This review covers recent findings in HMGB1 biology and cardiac dysfunction.

Constitutive DAMPs in CNS injury: From preclinical insights to clinical perspectives

Damage-associated molecular patterns (DAMPs) are endogenous molecules released in tissues upon cellular damage and necrosis, acting to initiate sterile inflammation. Constitutive DAMPs (cDAMPs) have the particularity to be present within the intracellular compartments of healthy cells, where they exert diverse functions such as regulation of gene expression and cellular homeostasis. However, after injury to the central nervous system (CNS), cDAMPs are rapidly released by stressed, damaged or dying neuronal, glial and endothelial cells, and can trigger inflammation without undergoing structural modifications. Several cDAMPs have been described in the injured CNS, such as interleukin (IL)-1α, IL-33, nucleotides (e.g. ATP), and high-mobility group box protein 1. Once in the extracellular milieu, these molecules are recognized by the remaining surviving cells through specific DAMP-sensing receptors, thereby inducing a cascade of molecular events leading to the production and release of proinflammatory cytokines and chemokines, as well as cell adhesion molecules. The ensuing immune response is necessary to eliminate cellular debris caused by the injury, allowing for damage containment. However, seeing as some molecules associated with the inflammatory response are toxic to surviving resident CNS cells, secondary damage occurs, aggravating injury and exacerbating neurological and behavioral deficits. Thus, a better understanding of these cDAMPs, as well as their receptors and downstream signaling pathways, could lead to identification of novel therapeutic targets for treating CNS injuries such as SCI, TBI, and stroke. In this review, we summarize the recent literature on cDAMPs, their specific functions, and the therapeutic potential of interfering with cDAMPs or their signaling pathways.

The dysfunction of complement and coagulation in diseases: the implications for the therapeutic interventions

The complement system, comprising over 30 proteins, is integral to the immune system, and the coagulation system is critical for vascular homeostasis. The activation of the complement and coagulation systems involves an organized proteolytic cascade, and the overactivation of these systems is a central pathogenic mechanism in several diseases. This review describes the role of complement and coagulation system activation in critical illness, particularly sepsis. The complexities of sepsis reveal significant knowledge gaps that can be compared to a profound abyss, highlighting the urgent need for further investigation and exploration. It is well recognized that the inflammatory network, coagulation, and complement systems are integral mechanisms through which multiple factors contribute to increased susceptibility to infection and may result in a disordered immune response during septic events in patients. Given the overlapping pathogenic mechanisms in sepsis, immunomodulatory therapies currently under development may be particularly beneficial for patients with sepsis who have concurrent infections. Herein, we present recent findings regarding the molecular relationships between the coagulation and complement pathways in the advancement of sepsis, and propose potential intervention targets related to the crosstalk between coagulation and complement, aiming to provide more valuable treatment of sepsis.

Oxidative Stress and Inflammation in Myocardial Ischemia-Reperfusion Injury: Protective Effects of Plant-Derived Natural Active Compounds

Acute myocardial infarction (AMI) remains a leading cause of death among patients with cardiovascular diseases. Percutaneous coronary intervention (PCI) has been the preferred clinical treatment for AMI due to its safety and efficiency. However, research indicates that the rapid restoration of myocardial oxygen supply following PCI can lead to secondary myocardial injury, termed myocardial ischemia-reperfusion injury (MIRI), posing a grave threat to patient survival. Despite ongoing efforts, the mechanisms underlying MIRI are not yet fully elucidated. Among them, oxidative stress and inflammation stand out as critical pathophysiological mechanisms, playing significant roles in MIRI. Natural compounds have shown strong clinical therapeutic potential due to their high efficacy, availability, and low side effects. Many current studies indicate that natural compounds can mitigate MIRI by reducing oxidative stress and inflammatory responses. Therefore, this paper reviews the mechanisms of oxidative stress and inflammation during MIRI and the role of natural compounds in intervening in these processes, aiming to provide a basis and reference for future research and development of drugs for treating MIRI.

Multifaceted role of HMGB1: From nuclear functions to cytoplasmic and extracellular signaling in inflammation and cancer-Review

High-mobility group box 1 (HMGB1) is a highly conserved nuclear protein involved in key nuclear processes such as DNA repair, replication, and gene regulation. Beyond its established nuclear roles, HMGB1 has crucial functions in the cytoplasm and extracellular environment. When translocated to the cytoplasm, HMGB1 plays a role in autophagy, cell survival, and immune response modulation. In its extracellular form, HMGB1 acts as a damage-associated molecular pattern molecule, initiating inflammatory responses by interacting with receptors such as Receptor for advanced glycation endproducts and Toll-like receptors. Recent studies have shown its role in promoting tissue regeneration, wound healing, and angiogenesis, highlighting its dual role in both inflammation and tissue repair. Notably, the redox status of HMGB1 influences its function, with the reduced form promoting autophagy and the disulfide form driving inflammation. Dysregulation of HMGB1 contributes to the progression of various diseases, including cancer, where it influences tumor growth, metastasis, and resistance to therapy. This review provides an overview of the nuclear, cytoplasmic, and extracellular roles of HMGB1, discussing its involvement in nuclear homeostasis, rare genetic diseases, autophagy, inflammation, cancer progression, and tissue regeneration.

The role of high mobility group proteins in cellular senescence mechanisms

Aging is a universal physiological phenomenon, and chronic age-related diseases have become one of the leading causes of human mortality, accounting for nearly half of all deaths. Studies have shown that reducing the incidence of these diseases can not only extend lifespan but also promote healthy aging. In recent years, the potential role of non-histone high-mobility group proteins (HMGs) in the regulation of aging and lifespan has attracted widespread attention. HMGs play critical roles in cellular senescence and associated diseases through various pathways, encompassing multi-layered mechanisms involving protein interactions, molecular regulation, and chromatin dynamics. This review provides a comprehensive analysis of the interactions between HMG family proteins and senescence-associated secretory phenotype (SASP), chromatin structure, and histone modifications, offering a deeper exploration of the pivotal functions and impacts of HMGs in the aging process. Furthermore, we summarize recent findings on the contributions of HMG proteins to aging and age-related diseases. HMG proteins not only regulate senescence-associated inflammation through modulating the SASP but also influence genomic stability and cell fate decisions via interactions with chromatin and histones. Targeting HMG proteins holds great potential in delaying the progression of aging and its associated diseases. This review aims to provide a systematic overview of HMG proteins' roles in aging and to lay a solid foundation for future anti-aging drug development and therapeutic strategies. With the advancing understanding of the mechanisms by which HMGs regulate aging, developing therapeutic interventions targeting HMGs may emerge as a promising approach to extending lifespan and enhancing healthspan.

Short Link N Modulates Inflammasome Activity in Intervertebral Discs Through Interaction with CD14

Intervertebral disc degeneration and pain are associated with the nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3) inflammasome activation and the processing of interleukin-1 beta (IL-1β). Activation of thehm inflammasome is triggered by Toll-like receptor stimulation and requires the cofactor receptor cluster of differentiation 14 (CD14). Short Link N (sLN), a peptide derived from link protein, has been shown to modulate inflammation and pain in discs in vitro and in vivo; however, the underlying mechanisms remain elusive. This study aims to assess whether sLN modulates IL-1β and inflammasome activity through interaction with CD14. Disc cells treated with lipopolysaccharides (LPS) with or without sLN were used to assess changes in Caspase-1, IL-1β, and phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). Peptide docking of sLN to CD14 and immunoprecipitation were performed to determine their interaction. The results indicated that sLN inhibited LPS-induced NFκB and Caspase-1 activation, reducing IL-1β maturation and secretion in disc cells. A significant decrease in inflammasome markers was observed with sLN treatment. Immunoprecipitation studies revealed a direct interaction between sLN and the LPS-binding pocket of CD14. Our results suggest that sLN could be a potential therapeutic agent for discogenic pain by mitigating IL-1β and inflammasome activity within discs.

Remimazolam ameliorates postoperative cognitive dysfunction after deep hypothermic circulatory arrest through HMGB1-TLR4-NF-κB pathway

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a complication of deep hypothermic circulatory arrest (DHCA). Various amounts of neurologic dysfunctions have been shown after DHCA, which has often been attributed to systemic inflammatory response syndrome and cerebral ischemia/reperfusion injury. Remimazolam is one of the commonly used anesthetic drugs with protective actions against inflammatory diseases, such as sepsis and cerebral ischemia/reperfusion injury. Here, we determined the protective effect and potential mechanism of action of remimazolam against neuronal damage after DHCA.

METHODS

A rat model of DHCA was established, and a gradient dosage of remimazolam was administered during cardiopulmonary bypass (CPB). The cognitive function of rats was evaluated by Morris water maze. Hematoxylin and eosin and TUNEL staining were performed to assess hippocampus tissue injury and neuronal apoptosis. Inflammatory cytokines concentration were analyzed by enzyme-linked immunosorbent assay. The protein expression was analyzed using automated electrophoresis western analysis and immunohistochemical analysis.

RESULTS

The appropriate dosage of remimazolam reduced histologic injury, neuronal apoptosis, microglia activation, and secondary inflammatory cascades, as well as the downregulation of the expression of the HMGB1-TLR4-NF-κB pathway after DHCA, improved the memory and learning abilities in DHCA rats. Further, administration of a TLR4 antagonist TAK-242 had a similar effect to remimazolam, while the TLR4 agonist LPS attenuated the effect of remimazolam.

CONCLUSIONS

Remimazolam could ameliorate POCD after DHCA through the HMGB1-TLR4-NF-κB signaling pathway.

Upregulations of high mobility group box 1 and TLR4/NF-κB signaling pathway in hippocampus and serum of rats with febrile seizure

PURPOSE

The aim of this study was to explore the alternations regarding the HMGB1 and TLR4/NF-κB signaling pathway in juvenile rats with febrile seizure (FS).

MATERIALS AND METHODS

During the animal modeling of the FS, seizures were triggered every four days by hot water (45 °C), and repeated ten times. After forty days' modeling, rats were divided into different groups according to the degree of seizure (FS (0) - FS (V)). Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expressions of the HMGB1, TLR4 and NF-κB in the hippocampus, while Western-blot (WB) and immunofluorescence (IF) were employed to assess protein expressions. The enzyme-linked immunosorbent assay (ELISA) was used for analyzing the protein expressions in peripheral blood.

RESULTS

The mRNA levels of the HMGB1, TLR4 and NF-κB in the hippocampus of both FS (V) and FS (IV) groups were significantly higher than WT, while there was no difference between FS (III) and WT. Concerning protein expressions, increased levels of the HMGB1, TLR4, and NF-κB in FS (V) were observed with a good consistency between the WB and IF, while no significant upregulation was shown in FS (IV). The ELISA results showed that the significance of the augmented proteins between the FS (V) and WT were smaller in the serum than the hippocampus.

CONCLUSIONS

Our study shows seizure degree-related upregulations of HMGB1 and TLR4/NF-κB signaling pathway both in hippocampus and serum of juvenile rats with FS, suggesting the involvement of TLR/NF-κB pathway in inflammation promoted by HMGB1 during FS.

Crosstalk between ferroptosis and macrophages: potential value for targeted treatment in diseases

Ferroptosis is a newly identified form of programmed cell death that is connected to iron-dependent lipid peroxidization. It involves a variety of physiological processes involving iron metabolism, lipid metabolism, oxidative stress, and biosynthesis of nicotinamide adenine dinucleotide phosphate, glutathione, and coenzyme Q10. So far, it has been discovered to contribute to the pathological process of many diseases, such as myocardial infarction, acute kidney injury, atherosclerosis, and so on. Macrophages are innate immune system cells that regulate metabolism, phagocytize pathogens and dead cells, mediate inflammatory reactions, promote tissue repair, etc. Emerging evidence shows strong associations between macrophages and ferroptosis, which can provide us with a deeper comprehension of the pathological process of diseases and new targets for the treatments. In this review, we summarized the crosstalk between macrophages and ferroptosis and anatomized the application of this association in disease treatments, both non-neoplastic and neoplastic diseases. In addition, we have also addressed problems that remain to be investigated, in the hope of inspiring novel therapeutic strategies for diseases.

High Mobility Group Box Protein (HMGB1): A Potential Therapeutic Target for Diabetic Encephalopathy

HMGB (high mobility group B) is one of the ubiquitous non-histone nuclear protein superfamilies that make up the HMG (high mobility group) protein group. HMGB1 is involved in a variety of physiological and pathological processes in the human body, including a structural role in the cell nucleus as well as replication, repair, DNA transcription, and assembly of nuclear proteins. It functions as a signaling regulator in the cytoplasm and a pro-inflammatory cytokine in the extracellular environment. Among several studies, HMGB1 protein is also emerging as a crucial factor involved in the development and progression of diabetic encephalopathy (DE) along with other factors such as hyperglycaemia-induced oxidative and nitrosative stress. Diabetes' chronic side effect is DE, which manifests as cognitive and psychoneurological dysfunction. The HMGB1 is released outside to the extracellular medium in diabetes condition through active or passive routes, where it functions as a damage-associated molecular pattern (DAMP) molecule to activate several signaling pathways by interacting with receptors for advanced glycosylation end-products (RAGE)/toll like receptors (TLR). HMGB1 reportedly activates inflammatory pathways, disrupts the blood-brain barrier, causes glutamate toxicity and oxidative stress, and promotes neuroinflammation, contributing to the development of cognitive impairment and neuronal damage which is suggestive of the involvement of HMGB1 in the enhancement of the diabetes-induced encephalopathic condition. Additionally, HMGB1 is reported to induce insulin resistance, further exacerbating the metabolic dysfunction associated with diabetes mellitus (DM). Thus, the present review explores the possible pathways associated with DM-induced hyperactivation of HMGB1 ultimately leading to DE.

Resolution of chronic inflammation and cancer

Chronic inflammation poses challenges to effective cancer treatment. Although anti-inflammatory therapies have shown short-term benefits, their long-term implications may be unfavorable because they fail to initiate the necessary inflammatory responses. Recent research underscores the promise of specialized pro-resolving mediators, which play a role in modulating the cancer microenvironment by promoting the resolution of initiated inflammatory processes and restoring tissue hemostasis. This review addresses current insights into how inflammation contributes to cancer pathogenesis and explores recent strategies to resolve inflammation associated with cancer.

Glycyrrhizin Protects Submandibular Gland Against Radiation Damage by Enhancing Antioxidant Defense and Preserving Mitochondrial Homeostasis

Aims: Radiotherapy inevitably causes radiation damage to the salivary glands (SGs) in patients with head and neck cancers (HNCs). Excessive reactive oxygen species (ROS) levels and imbalanced mitochondrial homeostasis are serious consequences of ionizing radiation in SGs; however, there are few mitochondria-targeting therapeutic approaches. Glycyrrhizin is the main extract of licorice root and exhibits antioxidant activity to relieve mitochondrial damage in certain oxidative stress conditions. Herein, the effects of glycyrrhizin on irradiated submandibular glands (SMGs) and the related mechanisms were investigated. Results: Glycyrrhizin reduced radiation damage in rat SMGs at both the cell and tissue levels, and promoted saliva secretion in irradiated SMGs. Glycyrrhizin significantly downregulated high-mobility group box-1 protein (HMGB1) and toll-like receptor 5 (TLR5). Moreover, glycyrrhizin significantly suppressed the increases in malondialdehyde and glutathione disulfide (GSSG) levels; elevated the activity of some critical antioxidants, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione (GSH); and increased the GSH/GSSG ratio in irradiated cells. Importantly, glycyrrhizin effectively enhanced thioredoxin-2 levels and scavenged mitochondrial ROS, inhibited the decline in mitochondrial membrane potential, improved adenosine triphosphate synthesis, preserved the mitochondrial ultrastructure, activated the proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α)/nuclear respiratory factor 1/2 (NRF1/2)/mitochondrial transcription factor A (TFAM) signaling pathway, and inhibited mitochondria-related apoptosis in irradiated SMG cells and tissues. Innovation: Radiotherapy causes radiation sialadenitis in HNC patients. Our data suggest that glycyrrhizin could be a mitochondria-targeted antioxidant for the prevention of radiation damage in SGs. Conclusion: These findings demonstrate that glycyrrhizin protects SMGs from radiation damage by downregulating HMGB1/TLR5 signaling, maintaining intracellular redox balance, eliminating mitochondrial ROS, preserving mitochondrial homeostasis, and inhibiting apoptosis.

Hesperidin alleviates terbuthylazine-induced ferroptosis via maintenance of mitochondria-associated endoplasmic reticulum membrane integrity in chicken hepatocytes

Terbuthylazine (TBA) is a common triazine herbicide used in agricultural production, which causes toxic damage in multiple tissues. Hesperidin (HSP) is a flavonoid derivative that has anti-inflammatory, antioxidant and cytoprotective effects, but its role in reducing toxic damage caused by pesticides is still unclear. In this study, we aimed to investigate the toxic effect of TBA exposure on chicken hepatocytes and the therapeutic effect of HSP on the TBA-induced hepatotoxicity. Our results demonstrated that HSP could alleviate TBA exposure-induced endoplasmic reticulum (ER) stress. Interestingly, TBA significantly disrupted the integrity of mitochondria-associated endoplasmic reticulum membrane (MAM), while HSP treatment showed the opposite tendency. In addition, TBA could significantly trigger ferroptosis in liver, and HSP treatment reversed ferroptosis under TBA exposure. These results suggested that HSP could inhibit ER stress and alleviate ferroptosis under TBA exposure via maintaining MAM integrity, which provided a novel strategy to take precautions against TBA toxicity.

Tumor-derived mitochondrial formyl peptides suppress tumor immunity through modification of the tumor microenvironment

Mitochondrial N-formylpeptides are released from damaged or dead cells to the extracellular spaces and cause inflammatory responses. The role of mitochondrial N-formylpeptides in aseptic systemic inflammatory response syndromes induced by trauma or cardiac surgery has been well investigated. However, there are no reports regarding the role of mitochondrial N-formylpeptides in cancer. In this study, we investigated the role of tumor cell-derived mitochondrial N-formylpeptides in anti-tumor immunity using knockout murine tumor cells of mitochondrial methionyl-tRNA formyltransferase (MTFMT), which catalyze N-formylation of mitochondrial DNA-encoded proteins. There was no apparent difference among the wild-type and MTFMT-knockout clones of E.G7-OVA cells with respect to morphology, mitochondrial dynamics, glycolysis and oxidative phosphorylation, oxygen consumption rate, or in vitro cell growth. In contrast, in vivo tumor growth of MTFMT-knockout cells was slower than that of wild-type cells. A reduced number of myeloid-derived suppressor cells and an increase of cytotoxic T-lymphocytes in the tumor tissues were observed in the MTFMT-knockout tumors. These results suggested that tumor cell-derived mitochondrial N-formylpeptides had a negative role in the host anti-tumor immunity through modification of the tumor microenvironment.

High Mobility Group Box-1 (HMGB1), a Key Mediator of Cognitive Decline in Neurotrauma with a Potential for Targeted Therapy: A Comprehensive Review

Neurotrauma plays a significant role in secondary injuries by intensifying the neuroinflammatory response in the brain. High Mobility Group Box-1 (HMGB1) protein is a crucial neuroinflammatory mediator involved in this process. Numerous studies have hypothesized about the underlying pathophysiology of HMGB1 and its role in cognition, but a definitive link has yet to be established. Elevated levels of HMGB1 in the hippocampus and serum have been associated with declines in cognitive performance, particularly in spatial memory and learning. This review also found that inhibiting HMGB1 can improve cognitive deficits following neurotrauma. Interestingly, HMGB1 levels are linked to the modulation of neuroplasticity and may offer neuroprotective effects in the later stages of neurotraumatic events. Consequently, administering HMGB1 during the acute phase may help reduce neuroinflammatory effects that lead to cognitive deficits in the later stages of neurotrauma. However, further research is needed to understand the time-dependent regulation of HMGB1 and the clinical implications of treatments targeting HMGB1 after neurotrauma.

High mobility group box 1 (HMGB1) is a potential disease biomarker in cell and mouse models of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disorder affecting 1:3500 male births and is associated with myofiber degeneration, regeneration, and inflammation. Glucocorticoid treatments have been the standard of care due to immunomodulatory/immunosuppressive properties but novel genetic approaches, including exon skipping and gene replacement therapy, are currently being developed. The identification of additional biomarkers to assess DMD-related inflammatory responses and the potential efficacy of these therapeutic approaches are thus of critical importance. The current study uses RNA sequencing of skeletal muscle from two mdx mouse models to identify high mobility group box 1 (HMGB1) as a candidate biomarker potentially contributing to DMD-related inflammation. HMGB1 protein content was increased in a human iPSC-derived skeletal myocyte model of DMD and microdystrophin treatment decreased HMGB1 back to control levels. In vivo, HMGB1 protein levels were increased in vehicle treated B10-mdx skeletal muscle compared to B10-WT and significantly decreased in B10-mdx animals treated with adeno-associated virus (AAV)-microdystrophin. However, HMGB1 protein levels were not increased in D2-mdx skeletal muscle compared to D2-WT, demonstrating a strain-specific difference in DMD-related immunopathology.

Noninflammatory 97-amino acid High Mobility Group Box 1 derived polypeptide disrupts and prevents diverse biofilms

BACKGROUND

Bacterial biofilm communities are embedded in a protective extracellular matrix comprised of various components, with its' integrity largely owed to a 3-dimensional lattice of extracellular DNA (eDNA) interconnected by Holliday Junction (HJ)-like structures and stabilised by the ubiquitous eubacterial DNABII family of DNA-binding architectural proteins. We recently showed that the host innate immune effector High Mobility Group Box 1 (HMGB1) protein possesses extracellular anti-biofilm activity by destabilising these HJ-like structures, resulting in release of biofilm-resident bacteria into a vulnerable state. Herein, we showed that HMGB1's anti-biofilm activity was completely contained within a contiguous 97 amino acid region that retained DNA-binding activity, called 'mB Box-97'.

METHODS

We engineered a synthetic version of this 97-mer and introduced a single amino acid change which lacked any post-translational modifications, and tested its activity independently and in combination with a humanised monoclonal antibody that disrupts biofilms by the distinct mechanism of DNABII protein sequestration.

FINDINGS

mB Box-97 disrupted and prevented biofilms, including those formed by the ESKAPEE pathogens, and importantly reduced measurable proinflammatory activity normally associated with HMGB1 in a murine lung infection model.

INTERPRETATION

Herein, we discuss the value of targeting the ubiquitous eDNA-dependent matrix of biofilms via mB Box-97 used singly or in a dual host-augmenting/pathogen-targeted cocktail to resolve bacterial biofilm infections.

FUNDING

This work was supported by NIH/NIDCD R01DC011818 to L.O.B. and S.D.G. and NIH/NIAID R01AI155501 to S.D.G.