HMGB1 as biomarker and drug target

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.

High mobility group box-1 protein promotes astrocytic CCL5 production through the MAPK/NF-κB pathway following spinal cord injury

Astrocytes act as immune cells that can produce a series of chemokines to attract large numbers of leucocytes to the lesion site, where they contribute to excessive inflammation following spinal cord injury (SCI). However, the relevant regulatory mechanism involved in chemokine production by astrocytes has not been fully elucidated. In the present study, we examined the correlation between C-C motif chemokine ligand 5 (CCL5) and high mobility group box-1 protein (HMGB1) in a T8-T10 spinal cord contusion model. Our results revealed that SCI-induced CCL5 protein levels increased synchronously with the increase in HMGB1. Administration of an HMGB1-neutralizing antibody significantly reduced the protein expression of CCL5 in the context of SCI. An in vitro study revealed that HMGB1 binding with TLR2/4 receptors potently facilitates the production of CCL5 by astrocytes by activating the intracellular ERK/JNK-mediated NF-κB pathway. Furthermore, the HMGB1-induced release of CCL5 from astrocytes is involved in promoting microglia/macrophage accumulation and M1 polarization. The inhibition of HMGB1 activity reduces microglia/macrophage infiltration by decreasing the expression of CCL5 and improves motor functional recovery following SCI. Our results provide insights into the new functions of HMGB1-mediated astrocytic CCL5 production, which elicits inflammatory cell recruitment to the site of injury; this recruitment is associated with excessive inflammation activation. These data may provide a new therapeutic strategy for central nervous system (CNS) inflammation.

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.

Determination of systemic inflammation response index (SIRI), systemic inflammatory index (SII), HMGB1, Mx1 and TNF levels in neonatal calf diarrhea with systemic inflammatory response syndrome

The objective of this study was to examine the values of MX dynamin-like GTPase 1 (Mx1), high mobility group box-1 (HMGB1), systemic inflammatory response index (SIRI), systemic inflammatory index (SII), tumor necrosis factor (TNF), and other hematological indices in calves with systemic inflammatory response syndrome (SIRS). The study material was divided into two groups: the SIRS group (comprising 13 calves) and the control group (comprising 10 calves). The independent samples t-test and Mann-Whitney U test were employed for normally distributed and non-normally distributed data, respectively. The relationship between the two groups was determined using Spearman correlation coefficient analysis. Significant differences were identified between the SIRS group and the control group with regard to white blood cell (WBC; P < 0.05), neutrophil (NEU; P < 0.01), and neutrophil-to-lymphocyte ratio (NLR; P < 0.001) values, in addition to SIRI (P < 0.05), SII (P < 0.01) values. Furthermore, HMGB1 (P < 0.001), Mx1 (P < 0.05), and TNF values (P < 0.001) demonstrated notable disparities between the two groups. As a result of this study, it was concluded that there were significant increases in inflammatory hematological indices, as well as in the levels of HMGB1, Mx1, and TNF, in calves with SIRS.

Emerging role of immunogenic cell death in cancer immunotherapy: Advancing next-generation CAR-T cell immunotherapy by combination

Immunogenic cell death (ICD) is a stress-driven form of regulated cell death (RCD) in which dying tumor cells' specific signaling pathways are activated to release damage-associated molecular patterns (DAMPs), leading to the robust anti-tumor immune response as well as a reversal of the tumor immune microenvironment from "cold" to "hot". Chimeric antigen receptor (CAR)-T cell therapy, as a landmark in anti-tumor immunotherapy, plays a formidable role in hematologic malignancies but falls short in solid tumors. The Gordian knot of CAR-T cells for solid tumors includes but is not limited to, tumor antigen heterogeneity or absence, physical and immune barriers of tumors. The combination of ICD induction therapy and CAR-T cell immunotherapy is expected to promote the intensive use of CAR-T cell in solid tumors. In this review, we summarize the characteristics of ICD, stress-responsive mechanism, and the synergistic effect of various ICD-based therapies with CAR-T cells to effectively improve anti-tumor capacity.

Pyroptosis and the fight against lung cancer

Pyroptosis, a newly characterized type of inflammatory programmed cell death (PCD), is usually triggered by multiple inflammasomes which can recognize different danger or damage-associated molecular patterns (DAMPs), leading to the activation of caspase-1 and the cleavage of gasdermin D (GSDMD). Gasdermin family pore-forming proteins are the executers of pyroptosis and are normally maintained in an inactive state through auto-inhibition. Upon caspases mediated cleavage of gasdermins, the pro-pyroptotic N-terminal fragment is released from the auto-inhibition of C-terminal fragment and oligomerizes, forming pores in the plasma membrane. This results in the secretion of interleukin (IL)-1β, IL-18, and high-mobility group box 1 (HMGB1), generating osmotic swelling and lysis. Current therapeutic approaches including chemotherapy, radiotherapy, molecularly targeted therapy and immunotherapy for lung cancer treatment efficiently force the cancer cells to undergo pyroptosis, which then generates local and systemic antitumor immunity. Thus, pyroptosis is recognized as a new therapeutic regimen for the treatment of lung cancer. In this review, we briefly describe the signaling pathways involved in pyroptosis, and endeavor to discuss the antitumor effects of pyroptosis and its potential application in lung cancer therapy, focusing on the contribution of pyroptosis to microenvironmental reprogramming and evocation of antitumor immune response.

Role of microRNA-505 during tumor progression and metastasis

Late diagnosis of cancer in advanced stages due to the lack of screening methods is considered as the main cause of poor prognosis and high mortality rate among these patients. Therefore, it is necessary to investigate the molecular tumor biology in order to introduce biomarkers that can be used in cancer screening programs and early diagnosis. MicroRNAs (miRNAs) have key roles in regulation of the cellular pathophysiological processes. Due to the high stability of miRNAs in body fluids, they are widely used as the non-invasive tumor markers. According to the numerous reports about miR-505 deregulation in a wide range of cancers, we investigated the role of miR-505 during tumor progression. It was shown that miR-505 mainly has the tumor suppressor functions through the regulation of signaling pathways, chromatin remodeling, and cellular metabolism. This review has an effective role in introducing miR-505 as a suitable marker for the early cancer diagnosis.

Molecular Insights into the Relationship Between Platelet Activation and Endothelial Dysfunction: Molecular Approaches and Clinical Practice

Platelets are one of the coagulation cells. When platelet activation occurs, many mediators are released and affect endothelial cells (ECs) and lead to endothelial dysfunction (ED). ED plays an important role in the pathogenesis of many diseases, including cardiovascular disease (CVD). Platelet are of important factors in ED. The release of mediators by platelets causes the stimulation of inflammatory pathways, oxidative stress, and apoptosis, which ultimately result in ED.On the other hand, platelet activation in CVD patients can be associated with a bad prognosis. Platelet activation can increase the level of markers such as p-selectin in the serum. Also, in this study, we have discussed the role of platelet as a diagnostic factor, as well as its use as a treatment option. In addition, we discussed some of the molecular pathways that are used to target platelet activation.

IGF2BP3 prevent HMGB1 mRNA decay in bladder cancer and development

BACKGROUND

IGF2BP3 functions as an RNA-binding protein (RBP) and plays a role in the posttranscriptional control of mRNA localization, stability, and translation. Its dysregulation is frequently associated with tumorigenesis across various cancer types. Nonetheless, our understanding of how the expression of the IGF2BP3 gene is regulated remains limited. The specific functions and underlying mechanisms of IGF2BP3, as well as the potential benefits of targeting it for therapeutic purposes in bladder cancer, are not yet well comprehended.

METHODS

The mRNA and protein expression were examined by RT-qPCR and western blotting, respectively. The methylation level of CpG sites was detected by Bisulfite sequencing PCR (BSP). The regulation of IGF2BP3 expression by miR-320a-3p was analyzed by luciferase reporter assay. The functional role of IGF2BP3 was determined through proliferation, colony formation, wound healing, invasion assays, and xenograft mouse model. The regulation of HMGB1 by IGF2BP3 was investigated by RNA immunoprecipitation (RIP) and mRNA stability assays.

RESULTS

We observed a significant elevation in IGF2BP3 levels within bladder cancer samples, correlating with more advanced stages and grades, as well as an unfavorable prognosis. Subsequent investigations revealed that the upregulation of IGF2BP3 expression is triggered by copy number gain/amplification and promoter hypomethylation in various tumor types, including bladder cancer. Furthermore, miR-320a-3p was identified as another negative regulator in bladder cancer. Functionally, the upregulation of IGF2BP3 expression exacerbated bladder cancer progression, including the proliferation, migration, and invasion of bladder cancer. Conversely, IGF2BP3 silencing produced the opposite effects. Moreover, IGF2BP3 expression positively correlated with inflammation and immune infiltration in bladder cancer. Mechanistically, IGF2BP3 enhanced mRNA stability and promoted the expression of HMGB1 by binding to its mRNA, which is a factor that promotes inflammation and orchestrates tumorigenesis in many cancers. Importantly, pharmacological inhibition of HMGB1 with glycyrrhizin, a specific HMGB1 inhibitor, effectively reversed the cancer-promoting effects of IGF2BP3 overexpression in bladder cancer. Furthermore, the relationship between HMGB1 mRNA and IGF2PB3 is also observed in mammalian embryonic development, with the expression of both genes gradually decreasing as embryonic development progresses.

CONCLUSIONS

Our present study sheds light on the genetic and epigenetic mechanisms governing IGF2BP3 expression, underscoring the critical involvement of the IGF2BP3-HMGB1 axis in driving bladder cancer progression. Additionally, it advocates for the investigation of inhibiting IGF2BP3-HMGB1 as a viable therapeutic approach for treating bladder cancer.

The anti-inflammatory effect of metformin: The molecular targets

Metformin is an anti-diabetic drug. Metformin mainly inhibits gluconeogenesis in the liver and reduces blood sugar. In addition to the anti-diabetic effects, many studies have revealed that metformin has anti-inflammatory effects. Various molecules were suggested to be the target of the metformin's anti-inflammatory effects. However, the conclusion is not clear. Metformin is related to a number of molecules and the identification of the main target in anti-inflammatory effects leads to the understanding of inflammation and metformin. In this article, I discuss each suggested molecule, involved mechanisms, and their relationship with various diseases.

DAMPs and radiation injury

The heightened risk of ionizing radiation exposure, stemming from radiation accidents and potential acts of terrorism, has spurred growing interests in devising effective countermeasures against radiation injury. High-dose ionizing radiation exposure triggers acute radiation syndrome (ARS), manifesting as hematopoietic, gastrointestinal, and neurovascular ARS. Hematopoietic ARS typically presents with neutropenia and thrombocytopenia, while gastrointestinal ARS results in intestinal mucosal injury, often culminating in lethal sepsis and gastrointestinal bleeding. This deleterious impact can be attributed to radiation-induced DNA damage and oxidative stress, leading to various forms of cell death, such as apoptosis, necrosis and ferroptosis. Damage-associated molecular patterns (DAMPs) are intrinsic molecules released by cells undergoing injury or in the process of dying, either through passive or active pathways. These molecules then interact with pattern recognition receptors, triggering inflammatory responses. Such a cascade of events ultimately results in further tissue and organ damage, contributing to the elevated mortality rate. Notably, infection and sepsis often develop in ARS cases, further increasing the release of DAMPs. Given that lethal sepsis stands as a major contributor to the mortality in ARS, DAMPs hold the potential to function as mediators, exacerbating radiation-induced organ injury and consequently worsening overall survival. This review describes the intricate mechanisms underlying radiation-induced release of DAMPs. Furthermore, it discusses the detrimental effects of DAMPs on the immune system and explores potential DAMP-targeting therapeutic strategies to alleviate radiation-induced injury.

Circulating microRNAs from plasma as preclinical biomarkers of epileptogenesis and epilepsy

Epilepsy frequently develops as a result of brain insult; however, there are no tools allowing to predict which patients suffering from trauma will eventually develop epilepsy. microRNAs are interesting candidates for biomarkers, as several of them have been described to change their levels in the brains, and in the plasma of epileptic subjects. This study was conducted to evaluate the usefulness of plasma miRNAs as epileptogenesis/epilepsy biomarkers. In our studies, we used a rat model of temporal lobe epilepsy. An epileptogenic insult was status epilepticus evoked by stimulation of the left lateral nucleus of the amygdala. Next, animals were continuously video and EEG monitored for 3 months. Blood was collected at 14, 30, 60, and 90 days after stimulation. Blood plasma was separated and miRNA levels were analyzed. We compared miRNA levels between sham-operated and stimulated animals, and between animals with high and low numbers of seizures. We propose three miRNAs that could be biomarkers of epilepsy: miR-671, miR-9a-3p and miR-7a-5p. According to us, miR-206-5p is a potential biomarker of epileptogenesis, and miR-221-3p is a potential biomarker of epilepsy severity. We think that these five miRNAs can be considered in the future as potential treatment targets.

Ox-LDL promotes M1-like polarization of macrophages through the miR-21-5p/SKP2/EP300 pathway

Oxidized low-density lipoprotein (ox-LDL) mediated inflammatory damage, which possibly induces atherosclerosis (AS); however, the role of miRNA in this process has rarely been reported. In this paper, we study the ox-LDL-related endothelial cell damage and changes of macrophages. The bioinformatics method was used to analyze the expression changes of miRNA in AS patients, luciferase assay was used to study the interaction of protein and miRNA, and co-IP and ubiquitination experiments were used to analyze protein interaction. Flow cytometry was used to detect the polarization of macrophages. Database analysis showed that the expression of miR-21-5p was upregulated in AS patients. Luciferase assay showed that miR-21-5p can bind to SKP2 and subsequently influence ubiquitination of EP300. Overexpression of EP300 strengthens the HMGB1-induced acetylation and subsequently mediates the dissociation of HMGB1 from SIRT1, and thus HMGB1 could be secreted outside the cell. The HMGB1 released from endothelial cells can promote macrophage M1 polarization. This study shows that ox-LDL activates the SKP2/EP300 pathway through promoting upregulation of miR-21-5p, thereby acetylating and secreting HMGB1 outside the endothelium, subsequently enhancing macrophage polarization to further stabilize the inflammation situation.

HMGB1 and Toll-like receptors: potential therapeutic targets in autoimmune diseases

HMGB1, a nucleoprotein, is expressed in almost all eukaryotic cells. During cell activation and cell death, HMGB1 can function as an alarm protein (alarmin) or damage-associated molecular pattern (DAMP) and mediate early inflammatory and immune response when it is translocated to the extracellular space. The binding of extracellular HMGB1 to Toll-like receptors (TLRs), such as TLR2 and TLR4 transforms HMGB1 into a pro-inflammatory cytokine, contributing to the occurrence and development of autoimmune diseases. TLRs, which are members of a family of pattern recognition receptors, can bind to endogenous DAMPs and activate the innate immune response. Additionally, TLRs are key signaling molecules mediating the immune response and play a critical role in the host defense against pathogens and the maintenance of immune balance. HMGB1 and TLRs are reported to be upregulated in several autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, type 1 diabetes mellitus, and autoimmune thyroid disease. The expression levels of HMGB1 and some TLRs are upregulated in tissues of patients with autoimmune diseases and animal models of autoimmune diseases. The suppression of HMGB1 and TLRs inhibits the progression of inflammation in animal models. Thus, HMGB1 and TLRs are indispensable biomarkers and important therapeutic targets for autoimmune diseases. This review provides comprehensive strategies for treating or preventing autoimmune diseases discovered in recent years.

Cisplatin Dependent Secretion of Immunomodulatory High Mobility Group Box 1 (HMGB1) Protein from Lung Cancer Cells

High mobility group box 1 (HMGB1) is secreted from activated immune cells, necrotic cells, and certain cancers. Previous studies have reported that different patterns of post-translational modification, particularly acetylation and oxidation, mediate HMGB1 release and confer distinct extracellular HMGB1 signaling activity. Here we report that cisplatin but not carboplatin induces secretion of HMGB1 from human A549 non-small cell lung cancer (NSCLC) cells. Cisplatin-mediated HMGB1 secretion was dose-dependent and was regulated by nuclear exportin 1 (XPO1) also known as chromosomal maintenance 1 (CRM1) rather than adenosine diphosphate (ADP)-ribosylation, acetylation, or oxidation. HMGB1, as well as lysine acetylation and cysteine disulfide oxidation of secreted HMGB1, were monitored by sensitive and specific assays using immunoprecipitation, stable isotope dilution, differential alkylation, and nano liquid chromatography parallel reaction monitoring/high-resolution mass spectrometry (nano-LC-PRM/HRMS). A major fraction of the HMGB1 secreted by low-dose cisplatin treatment of A549 NSCLC cells was found to be in the fully reduced form. In contrast, mainly oxidized forms of HMGB1 were secreted by dimethyl sulfoxide (DMSO)-mediated apoptosis. These findings suggest that inhibition of XPO1 could potentiate the anti-tumor activity of cisplatin by increasing the nuclear accumulation of HMGB1 protein, an inhibitor of cisplatin DNA-adduct repair. Furthermore, low-dose cisplatin therapy could modulate the immune response in NSCLC through the established chemokine activity of extracellular reduced HMGB1. This could potentially enhance the efficacy of subsequent immunotherapy treatment.

HMGB1 is related to disease activity in children with celiac disease

INTRODUCTION

We aim to evaluate of the relationship between high mobility gene box-1 (HMGB1) levels and clinical, laboratory and histopathological findings at diagnosis and in remission in children with Celiac Disease (CD).

MATERIAL AND METHODS

The study included 36 celiac patients at diagnosis, 36 celiac patients in remission, and 36 healthy controls. Patients with intestinal pathologies other than CD, and accompanying inflammatory and/or autoimmune diseases were excluded. Relationship between HMGB1 levels and clinical, laboratory and histopathological findings were evaluated.

RESULTS

A total of 72 celiac patients [36 (18 girls, 18 boys, mean age 9.41±3.9 years) in group 1 and 36 (18 girls, 18 boys, mean age 9.91±3.36 years) in group 2] and 36 healthy controls in group 3 (19 girls, 17 boys, mean age 9.56±4 years) were included. The HMGB1 level was significantly higher in group 1 compared to group 2 and group 3 [36.63 (17.98-54.72) ng/ml vs 20.31 (16.89-29.79) ng/ml, p = 0.028 and 36.63 (17.98-54.72) ng/ml vs 20.38 (17.54-24.53) ng/ml p = 0.012, respectively]. A serum HMGB-1 level of 26.553 ng/ml was found to be a cut-off value for the CD with 61% sensitivity, 83% specificity, 78% positive predictive value, and 68% negative predictive value. Higher HMGB1 values were seen in patients with intestinal findings, anemia, anti-tissue transglutaminase IgA levels that were greater than 10 times upper limit of normal, and patients with a higher degree of atrophy as classified by Marsh-Oberhuber.

CONCLUSIONS

In conclusion, it was thought that HMGB-1 might be a marker that reflects the severity of atrophy at the time of diagnosis and could be used to control dietary compliance in the follow-up. However, there is need for larger population studies in order to evaluate its value as a serological marker for the diagnosis and follow-up of CD and to find a more reliable cut-off value.

Research on the interaction of astragaloside IV and calycosin in Astragalus membranaceus with HMGB1

BACKGROUND

High mobility group box 1 protein (HMGB1), a lethal late inflammatory mediator, contributes to the pathogenesis of diverse inflammatory and infectious diseases. Astragaloside IV and calycosin as active ingredients in Astragalus membranaceus, possess potent regulatory ability on HMGB1-induced inflammation, however, the interaction between these two phytochemicals and HMGB1 has not been elucidated yet.

METHODS

To further investigate the interaction of astragaloside IV, calycosin with HMGB1 protein, surface plasma resonance (SPR) and a series of spectroscopic methods, including UV spectra, fluorescence spectroscopy, circular dichroism (CD), were used. Molecular docking was also carried out to predict the atomic level's binding modes between two components and HMGB1.

RESULTS

Astragaloside IV and calycosin were found to be able to bind HMGB1 directly and affect the secondary structure and environment of the chromogenic amino acids of HMGB1 to different extents. In silico, astragaloside IV and calycosin showed a synergistic effect by binding to the two independent domains B-box and A-box in HMGB1, respectively, where hydrogen and hydrophobicity bonds were regarded as the crucial forces.

CONCLUSION

These findings showed that the interaction of astragaloside IV and calycosin with HMGB1 impaired its proinflammatory cytokines function, providing a new perspective for understanding the mechanism of A. membranaceus in treating aseptic and infectious diseases.

HMGB-1 Levels in Painful Knee Arthroplasty: Is it Possible to Distingue Periprosthetic Joint Infection and Aseptic Loosening?

Introduction

We investigated the efficiency of high mobility group box-1 protein (HMGB-1) in differentiation of asymptomatic knee prosthesis, and periprosthetic joint infection and aseptic loosening causing painful knee prosthesis.

Materials and Methods

The data of patients who consulted our clinic for checking after total knee arthroplasty surgery were recorded prospectively. Blood levels of CRP, ESR, WBC, and HMGB-1 were recorded. Patients whose examination and routine tests were within normal limits comprised group I, asymptomatic total knee arthroplasty (ATKA). Painful patients with abnormal test results underwent three phase bone scintigraphy for further investigation Patients with periprosthetic joint infection (PJI) and aseptic loosening (AL) according to scintigraphy comprised group II and group III, respectively. The mean values of HMGB-1 and cut-off values according to the groups and their correlations with other inflammatory parameters were determined.

Results

Seventy-three patients were included in the study. Significant differences were observed in three groups, in terms of CRP, ESR, WBC, and HMGB-1. The cut-off value of HMGB-1 was determined as 15.16 ng/ml between ATKA and PJI, 16.92 ng/ml between ATKA and AL, and 27.87 ng/ml between PJI and AL, respectively. Accordingly, the sensitivity, and specificity of HMGB-1 in differentiation of ATKA and PJI were 91%, 88%, and in differentiation of ATKA and AL were 91%, 96%, and in differentiation of PJI and AL were 81%, 73%, respectively.

Conclusion

HMGB-1 may be utilized as an additional blood test in the differential diagnosis of problematic knee prosthesis patients.

Fiber Optic Localized Surface Plasmon Resonance Sensor Based on Carboxymethylated Dextran Modified Gold Nanoparticles Surface for High Mobility Group Box 1 (HMGB1) Analysis

Rapid, sensitive, and reliable detection of high mobility group box 1 (HMGB1) is essential for medical and diagnostic applications due to its important role as a biomarker of chronic inflammation. Here, we report a facile method for the detection of HMGB1 using carboxymethyl dextran (CM-dextran) as a bridge molecule modified on the surface of gold nanoparticles combined with a fiber optic localized surface plasmon resonance (FOLSPR) biosensor. Under optimal conditions, the results showed that the FOLSPR sensor detected HMGB1 with a wide linear range (10^-10 to 10^-6 g/mL), fast response (less than 10 min), and a low detection limit of 43.4 pg/mL (1.7 pM) and high correlation coefficient values (>0.9928). Furthermore, the accurate quantification and reliable validation of kinetic binding events measured by the currently working biosensors are comparable to surface plasmon resonance sensing systems, providing new insights into direct biomarker detection for clinical applications.

Analysis of the influence of pyroptosis-related genes on molecular characteristics in patients with acute myocardial infarction

Pyroptosis is a newly identified mode of programmed cell death, but the potential role in patients with acute myocardial infarction (AMI) remains unclear. In this study, bioinformatics methods were used to identify differentially expressed genes from peripheral blood transcriptome data between normal subjects and patients with AMI which were downloaded by the Gene Expression Omnibus database. Comparing Random Forest (RF) and Support Vector Machine (SVM) training algorithms were used to identify pyroptosis-related genes, predicting patients with AMI by nomogram based on informative genes. Moreover, clustering was used to amplify the feature of pyroptosis, in order to facilitate analysis distinct biological differences. Diversity analysis indicated that a majority of pyroptosis-related genes are expressed at higher levels in patients with AMI. The receiver operating characteristic curves show that the RF model is more responsive than the SVM machine learning model to the pyroptosis characteristics of these patients in vivo. We obtained a column line graph diagnostic model which was developed based on 19 genes established by the RF model. After the consensus clustering algorithm of single sample Gene Set Enrichment Analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment Analysis, the results for them found that pyroptosis-related genes mediate the activation of multiple immune cells and many inflammatory pathways in the body. We used RF and SVM algorithms to determine 19 pyroptosis-related genes and evaluate their immunological effects in patients with AMI. We also constructed a series of by nomogram related to pyroptosis-related genes to predict the risk of developing AMI.

Nrf2: A Main Responsive Element of the Toxicity Effect Caused by Trichothecene (T-2) Mycotoxin

T-2 toxin, the most toxic type A trichothecene mycotoxin, is produced by Fusarium, and is widely found in contaminated feed and stored grains. T-2 toxin is physicochemically stable and is challenging to eradicate from contaminated feed and cereal, resulting in food contamination that is inescapable and poses a major hazard to both human and animal health, according to the World Health Organization. Oxidative stress is the upstream cause of all pathogenic variables, and is the primary mechanism through which T-2 toxin causes poisoning. Nuclear factor E2-related factor 2 (Nrf2) also plays a crucial part in oxidative stress, iron metabolism and mitochondrial homeostasis. The major ideas and emerging trends in future study are comprehensively discussed in this review, along with research progress and the molecular mechanism of Nrf2's involvement in the toxicity impact brought on by T-2 toxin. This paper could provide a theoretical foundation for elucidating how Nrf2 reduces oxidative damage caused by T-2 toxin, and a theoretical reference for exploring target drugs to alleviate T-2 toxin toxicity with Nrf2 molecules.

PARP1 Activation Induces HMGB1 Secretion Promoting Intestinal Inflammation in Mice and Human Intestinal Organoids

Extracellular High-mobility group box 1 (HMGB1) contributes to the pathogenesis of inflammatory disorders, including inflammatory bowel diseases (IBD). Poly (ADP-ribose) polymerase 1 (PARP1) has been recently reported to promote HMGB1 acetylation and its secretion outside cells. In this study, the relationship between HMGB1 and PARP1 in controlling intestinal inflammation was explored. C57BL6/J wild type (WT) and PARP1^-/- mice were treated with DSS to induce acute colitis, or with the DSS and PARP1 inhibitor, PJ34. Human intestinal organoids, which are originated from ulcerative colitis (UC) patients, were exposed to pro-inflammatory cytokines (INFγ + TNFα) to induce intestinal inflammation, or coexposed to cytokines and PJ34. Results show that PARP1^-/- mice develop less severe colitis than WT mice, evidenced by a significant decrease in fecal and serum HMGB1, and, similarly, treating WT mice with PJ34 reduces the secreted HMGB1. The exposure of intestinal organoids to pro-inflammatory cytokines results in PARP1 activation and HMGB1 secretion; nevertheless, the co-exposure to PJ34, significantly reduces the release of HMGB1, improving inflammation and oxidative stress. Finally, HMGB1 release during inflammation is associated with its PARP1-induced PARylation in RAW264.7 cells. These findings offer novel evidence that PARP1 favors HMGB1 secretion in intestinal inflammation and suggest that impairing PARP1 might be a novel approach to manage IBD.

Integrative applications of network pharmacology and molecular docking: An herbal formula ameliorates H9c2 cells injury through pyroptosis

Background

QiShen YiQi pills (QSYQ) is a Traditional Chinese Medicine (TCM) formula, which has a significant effect on the treatment of patients with myocardial infarction (MI) in clinical practice. However, the molecular mechanism of QSYQ regulation pyroptosis after MI is still not fully known. Hence, this study was designed to reveal the mechanism of the active ingredient in QSYQ.

Methods

Integrated approach of network pharmacology and molecular docking, were conducted to screen active components and corresponding common target genes of QSYQ in intervening pyroptosis after MI. Subsequently, STRING and Cytoscape were applied to construct a PPI network, and obtain candidate active compounds. Molecular docking was performed to verify the binding ability of candidate components to pyroptosis proteins and oxygen-glucose deprivation (OGD) induced cardiomyocytes injuries were applied to explore the protective effect and mechanism of the candidate drug.

Results

Two drug-likeness compounds were preliminarily selected, and the binding capacity between Ginsenoside Rh2 (Rh2) and key target High Mobility Group Box 1 (HMGB1)was validated in the form of hydrogen bonding. 2 μM Rh2 prevented OGD-induced H9c2 death and reduced IL-18 and IL-1β levels, possibly by decreasing the activation of the NLRP3 inflammasome, inhibiting the expression of p12-caspase1, and attenuating the level of pyroptosis executive protein GSDMD-N.

Conclusions

We propose that Rh2 of QSYQ can protect myocardial cells partially by ameliorating pyroptosis, which seems to have a new insight regarding the therapeutic potential for MI.

Review: The role of HMGB1 in spinal cord injury

High mobility group box 1 (HMGB1) has dual functions as a nonhistone nucleoprotein and an extracellular inflammatory cytokine. In the resting state, HMGB1 is mainly located in the nucleus and regulates key nuclear activities. After spinal cord injury, HMGB1 is rapidly expressed by neurons, microglia and ependymal cells, and it is either actively or passively released into the extracellular matrix and blood circulation; furthermore, it also participates in the pathophysiological process of spinal cord injury. HMGB1 can regulate the activation of M1 microglia, exacerbate the inflammatory response, and regulate the expression of inflammatory factors through Rage and TLR2/4, resulting in neuronal death. However, some studies have shown that HMGB1 is beneficial for the survival, regeneration and differentiation of neurons and that it promotes the recovery of motor function. This article reviews the specific timing of secretion and translocation, the release mechanism and the role of HMGB1 in spinal cord injury. Furthermore, the role and mechanism of HMGB1 in spinal cord injury and, the challenges that still need to be addressed are identified, and this work will provide a basis for future studies.

Dietary puerarin supplementation improves immune function in the small intestines of oxidized oil-challenged broilers

Puerarin has possessed a wide range of pharmacological activities. However, little is known about the protective effects of puerarin on the oxidized oil-induced injury. Here, we describe the anti-inflammatory effects of puerarin in chickens. A total of 360 broilers were arranged in four treatments. Diets included two types of soybean oil (fresh or oxidized) and two levels of puerarin (0 or 750 mg/kg). Results showed that puerarin alleviated oxidized soybean oil-induced intestinal immune injury by decreasing the expressions of HSP and pro-inflammatory factor (P < 0.05) and enhancing the mRNA levels of anti-inflammatory factor and CATH-1 (P < 0.05) in broilers. Moreover, puerarin supplementation decreased the mRNA abundances of TLR4 and MyD88 (P < 0.05) and upregulated the expressions of A20 and SOCS-1 (P < 0.05) in the small intestine of oxidized soybean oil-challenged broilers. Collectively, this study demonstrates puerarin may be a potential nutrient supplement in the treatment of oxidized oil-induced damage in poultry.

Reappraisal of oxidized HMGB1 as a mediator and biomarker

HMGB1 is a dual-function protein that acts as a chromatin-binding protein and as a danger-associated molecular pattern (DAMP) when released from activated immune cells or injured tissue. In much of the HMGB1 literature, immunomodulatory effects of extracellular HMGB1 are proposed to depend on its oxidation state. However, many of the foundational studies for this model have been retracted or flagged with expressions of concern. The literature on HMGB1 oxidation reveals a diversity of redox proteoforms of HMGB1 that are inconsistent with current models of redox modulation regulating HMGB1 secretion. A recent study of acetaminophen toxicity has identified previously unrecognized HMGB1 oxidized proteoforms. HMGB1 undergoes oxidative modifications that could serve as pathology-specific biomarkers and drug targets.

Progress in Research on TLR4-Mediated Inflammatory Response Mechanisms in Brain Injury after Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is one of the common clinical neurological emergencies. Its incidence accounts for about 5-9% of cerebral stroke patients. Even surviving patients often suffer from severe adverse prognoses such as hemiplegia, aphasia, cognitive dysfunction and even death. Inflammatory response plays an important role during early nerve injury in SAH. Toll-like receptors (TLRs), pattern recognition receptors, are important components of the body's innate immune system, and they are usually activated by damage-associated molecular pattern molecules. Studies have shown that with TLR 4 as an essential member of the TLRs family, the inflammatory transduction pathway mediated by it plays a vital role in brain injury after SAH. After SAH occurrence, large amounts of blood enter the subarachnoid space. This can produce massive damage-associated molecular pattern molecules that bind to TLR4, which activates inflammatory response and causes early brain injury, thus resulting in serious adverse prognoses. In this paper, the process in research on TLR4-mediated inflammatory response mechanism in brain injury after SAH was reviewed to provide a new thought for clinical treatment.

Guggulsterone Induces Apoptosis in Multiple Myeloma Cells by Targeting High Mobility Group Box 1 via Janus Activated Kinase/Signal Transducer and Activator of Transcription Pathway

Multiple myeloma (MM) is a hematological disorder characterized by the abnormal expansion of plasma cells in the bone marrow. Despite great advances over the past three decades in discovering the efficacious therapies for MM, the disease remains incurable for most patients owing to emergence of drug-resistant cancerous cells. Guggulsterone (GS), a phytosteroid, extracted from the gum resin of guggul plant, has displayed various anticancer activities in vitro and in vivo; however, the molecular mechanisms of its anticancer activity have not been evaluated in MM cells. Therefore, in this study, we investigated the anticancer activity of GS in various MM cell lines (U266, MM.1S, and RPMI 8226) and the mechanisms involved. GS treatment of MM cells caused inhibition of cell proliferation and induction of apoptotic cell death as indicated by increased Bax protein expression, activation of caspases, and cleavage of poly (ADP-ribose) polymerase. This was associated with the downregulation of various proliferative and antiapoptotic gene products, including cyclin D, Bcl-2, Bcl-xL, and X-linked inhibitor of apoptosis protein. GS also suppressed the constitutive and interleukin 6-induced activation of STAT3. Interestingly, the inhibition of Janus activated kinase or STAT3 activity by the specific inhibitors or by siRNA knockdown of STAT3 resulted in the downregulation of HMGB1, suggesting an association between GS, STAT3, and HMGB1. Finally, GS potentiated the anticancer effects of bortezomib (BTZ) in MM cells. Herein, we demonstrated that GS could be a potential therapeutic agent for the treatment of MM, possibly alone or in combination with BTZ.

Translocation of High Mobility Group Box 1 From the Nucleus to the Cytoplasm in Depressed Patients With Epilepsy

Depression is a common psychiatric comorbidity in patients with epilepsy, especially those with temporal lobe epilepsy (TLE). The aim of this study was to assess changes in high mobility group box protein 1 (HMGB1) expression in epileptic patients with and without comorbid depression. Sixty patients with drug-resistant TLE who underwent anterior temporal lobectomy were enrolled. Anterior hippocampal samples were collected after surgery and analyzed by immunofluorescence (n  = 7/group). We also evaluated the expression of HMGB1 in TLE patients with hippocampal sclerosis and measured the level of plasma HMGB1 by enzyme-linked immunosorbent assay. The results showed that 28.3% of the patients (17/60) had comorbid depression. HMGB1 was ubiquitously expressed in all subregions of the anterior hippocampus. The ratio of HMGB1-immunoreactive neurons and astrocytes was significantly increased in both TLE patients with hippocampal sclerosis and TLE patients with comorbid depression compared to patients with TLE only. The ratio of cytoplasmic to nuclear HMGB1-positive neurons in the hippocampus was higher in depressed patients with TLE than in nondepressed patients, which suggested that more HMGB1 translocated from the nucleus to the cytoplasm in the depressed group. There was no significant difference in the plasma level of HMGB1 among patients with TLE alone, TLE with hippocampal sclerosis, and TLE with comorbid depression. The results of the study revealed that the translocation of HMGB1 from the nucleus to the cytoplasm in hippocampal neurons may play a previously unrecognized role in the initiation and amplification of epilepsy and comorbid depression. The direct targeting of neural HMGB1 is a promising approach for anti-inflammatory therapy.

Ultrasonically Enhanced ZD2767P–Carboxypeptidase G2 Deactivates Cisplatin-Resistant Human Lung Cancer Cells

The prodrug–enzyme regimen ZD2767P+CPG2 is limited by low efficacy. Here, ultrasound was used to modulate ZD2767P+CPG2 (i.e., ZD2767P+CPG2+US) against cisplatin-resistant human lung cancer cells. A549 and A549/DDP (resistant subline) cells received ZD2767P+CPG2 or ZD2767P+CPG2+US. Either ZD2767P+CPG2 or ZD2767P+CPG2+US led to cell death and apoptosis, and ZD2767P+CPG2+US produced stronger effects; comet assays revealed that these two means directly caused DNA double-strand break. Z-VAD-fmk and/or ferrostatin-1 increased the cell survival percentage, and Z-VAD-fmk decreased the apoptosis percentage. The level of transferrin was increased in treated cells, but those of ferroportin and glutathione peroxidase 4 (GPX4) were reduced, with higher intracellular levels of reactive oxygen species and of iron. Intracellular pharmacokinetics of ZD2767D (activated drug) indicated that the peak level, area under the drug level vs. time curve, and mean residence time in ZD2767P+CPG2+US were higher than those in ZD2767P+CPG2. Both ZD2767P+CPG2 and ZD2767P+CPG2+US were effective on xenograft tumors in nude mice; inhibitory rates were 39.7% and 63.5% in A549 tumors and 50.0% and 70.1% in A549/DDP tumors, respectively. A higher apoptosis level and a lower GPX4 level were noted in tumors receiving treatments. No severe adverse events were observed. These data demonstrated that ZD2767P+CPG2+US deactivated cancer cells via apoptosis and ferroptosis pathways, being a candidate therapy for cisplatin-resistant lung cancer.

Characterization and Quantification of Oxidized High Mobility Group Box 1 Proteoforms Secreted from Hepatocytes by Toxic Levels of Acetaminophen

The high mobility group box 1 (HMGB1), which is released during acute acetaminophen (APAP) overdose, is thought to mediate a subsequent immune response, particularly hepatic infiltration of macrophages. The redox behavior of HMGB1 and the proteoforms of HMGB1 present in oxidative environments has been the subject of a number of confusing and contradictory studies. Therefore, a stable isotope dilution two-dimensional nanoultrahigh-performance liquid chromatography parallel reaction monitoring/high-resolution mass spectrometry method was developed in order to characterize and quantify oxidative modifications to the cysteine (Cys) residues (Cys-23, Cys-45, and Cys-106) that are present in HMGB1. Disulfide linkages were determined using carbamidoethyl derivatization before and after reduction as well as by direct analysis of disulfide cross-linked peptides. A stable isotope labeled form of HMGB1 was used as an internal standard to correct for sample to sample differences in immunoaffinity precipitation, derivatization, and electrospray ionization. Four discrete HMGB1 proteoforms were found to be released from a hepatocarcinoma cell model of APAP overdose after 24 h. Fully reduced HMGB1 with all three Cys-residues in their free thiol state accounted for 18% of the secreted HMGB1. The proteoform with disulfide between Cys-23 and Cys-45 accounted for 24% of the HMGB1. No evidence was obtained for a disulfide cross-link between Cys-106 and the other two Cys-residues. However, 45% of the HMGB1 formed a cross-link with unidentified intracellular proteins via an intermolecular disulfide bond, and 12% was present as the terminally oxidized cysteic acid. Surprisingly, there was no evidence for the formation of HMGB1 disulfides with GSH or other low molecular weight thiols. Secreted plasma HMGB1 Cys-23/Cys45 disulfide proteoform together with the Cys-106/protein disulfide proteoforms could potentially serve as early biomarkers of hepatoxicity after APAP overdose as well as biomarkers of drug-induced liver injury.

Spotlight on liver macrophages for halting liver disease progression and injury

INTRODUCTION

Over the past two decades, understanding of hepatic macrophage biology has provided astounding details of their role in the progression and regression of liver diseases. The hepatic macrophages constitute resident macrophages, Kupffer cells, and circulating bone marrow monocyte-derived macrophages, which play a diverse role in liver injury and repair. Imbalance in the macrophage population leads to pathological consequences and is responsible for the initiation and progression of acute and chronic liver injuries. Further, distinct populations of hepatic macrophages and their high heterogeneity make their complex role enigmatic. The unique features of distinct phenotypes of macrophages have provided novel biomarkers for defining the stages of liver diseases. The distinct mechanisms of hepatic macrophages polarization and recruitment have been at the fore front of research. In addition, the secretome of hepatic macrophages and their immune regulation has provided clinically relevant therapeutic targets.

AREAS COVERED

Herein we have highlighted the current understanding in the area of hepatic macrophages, and their role in the progression of liver injury.

EXPERT OPINION

It is essential to ascertain the physiological and pathological role of evolutionarily conserved distinct macrophage phenotypes in different liver diseases before viable approaches may see a clinical translation.

AllergoOncology: Danger signals in allergology and oncology: A European Academy of Allergy and Clinical Immunology (EAACI) Position Paper

The immune system interacts with many nominal 'danger' signals, endogenous danger-associated (DAMP), exogenous pathogen (PAMP) and allergen (AAMP)-associated molecular patterns. The immune context under which these are received can promote or prevent immune activating or inflammatory mechanisms and may orchestrate diverse immune responses in allergy and cancer. Each can act either by favouring a respective pathology or by supporting the immune response to confer protective effects, depending on acuity or chronicity. In this Position Paper under the collective term danger signals or DAMPs, PAMPs and AAMPs, we consider their diverse roles in allergy and cancer and the connection between these in AllergoOncology. We focus on their interactions with different immune cells of the innate and adaptive immune system and how these promote immune responses with juxtaposing clinical outcomes in allergy and cancer. While danger signals present potential targets to overcome inflammatory responses in allergy, these may be reconsidered in relation to a history of allergy, chronic inflammation and autoimmunity linked to the risk of developing cancer, and with regard to clinical responses to anti-cancer immune and targeted therapies. Cross-disciplinary insights in AllergoOncology derived from dissecting clinical phenotypes of common danger signal pathways may improve allergy and cancer clinical outcomes.

Application of Biomarkers in the Diagnostic Distinction of Bacterial and Viral Infections

Infectious diseases, which pose a great threat worldwide, have a significant impact on public health and the world economy. It contributes to increased healthcare costs, unnecessary drug-related side effects, and increased antimicrobial resistance. It is not always easy to distinguish the etiological differentiation of diseases that can develop with bacteria and viruses. Therefore, one of the biggest challenges in medicine is how to correctly distinguish between the different causes of these infections and how to manage the patient. Because bacterial and viral infections often present similar symptoms. The real decision is whether the infection is caused by bacteria or viruses and whether to treat the patient with antibiotics. There are many different methodological approaches to diagnosing infections. Biomarkers have been used in the diagnosis of diseases and other conditions for many years. Biomarkers are molecules found in blood and body fluids in measurable amounts, which can evaluate biological and pathological processes. These key indicators can provide vital information in determining disease prognosis, predicting response to treatments, adverse events and drug interactions, and identifying key risks. An effective biomarker is extremely important for the early diagnosis of various diseases. The explosion of interest in biomarker research is driving the development of new predictive, diagnostic, and prognostic products in modern medical practice. The purpose of this review is to demonstrate the use and diagnostic potential of current and investigational biomarkers in the distinction between bacterial and viral infections.

Astrocytic CD24 Protects Neuron from Recombinant High-Mobility Group Box 1 Protein(rHMGB1)-Elicited Neuronal Injury

Endogenous host-derived molecules named damage-associated molecular patterns (DAMPs) can induce excessive non-sterile inflammatory responses on recognition of specific membrane-tethered receptors. Here in this study, we aimed to explore the role of DAMP molecule HMGB1 in astrocyte-mediated sterile neuroinflammation and the resultant influences on neurons. In vitro cultured astrocytes were challenged with rHMGB1 and then harvested at 6 h, 12 h, 24 h, 36 h, and 48 h, respectively. The astrocytic CD24 expression was determined by quantitative real-time polymerase chain reaction (qPCR), Western blot analysis and immunofluorescence, nuclear factor kappa B (NF-κB) binding activity was detected by electrophoretic mobility shift assay (EMSA), and the proinflammatory factors, tumor necrosis factor-α (TNF-α), and interleukin 1β (IL-1β), were measured by qPCR. The neuronal morphology was assessed with phase-contrast microscopy. The results showed that astrocytic mRNA and protein CD24 expression began to rise at 24 h, peaked at 36 h, and remained elevated at 48 h after rHMGB1 stimulation, accompanied with enhanced NF-κB binding activity and augmented expression of TNF-α and IL-1β. Furthermore, rHMGB1 caused cocultured neuron damage and was aggregated upon CD24 knockdown. Taken together, these novel findings suggested that rHMGB1 could promote astrocytic CD24 expression, the inhibition of which could aggregate neuronal damage.

Ginsenoside Rh2 Inhibits NLRP3 Inflammasome Activation and Improves Exosomes to Alleviate Hypoxia-Induced Myocardial Injury

The inflammatory microenvironment after acute myocardial infarction (MI) is a key limiting factor in the clinical application of stem cell transplantation and paracrine exosome therapy. Qishen Yiqi Pills contain a saponin ingredient called Ginsenoside Rh2 (Rh2) which exhibits a certain therapeutic effect on MI. However, the mechanism by which Rh2 alleviates the inflammatory microenvironment and improves the therapeutic efficiency of exosomes remains enigmatic. Here, we found that Rh2 attenuated the adverse effect of oxygen-glucose deprivation (OGD)-induced cellular injury, an in vitro pathological model of MI. Confocal microscopy revealed that DiI-labeled BMSCs-derived exosomes exhibited an increased homing ability of cardiomyocytes, which, in turn, inhibited the nuclear translocation of NF-κB p65 and NLRP3 inflammasome activation, thereby alleviating the inflammatory microenvironment and further facilitating the homing of exosomes to cardiomyocytes by forming a feed-forward enhancement loop. Additionally, we found that Rh2 could regulate the HMGB1/NF-κB signaling pathway to improve the OGD environment of cardiomyocytes, increasing the efficiency of the feed-forward loop. In conclusion, we found that Rh2 can improve the inflammatory microenvironment by enhancing the protection of exosomes against myocardial injury, providing new insights into the indirect modification of exosomes by Rh2 in MI treatment.

High Mobility Group Proteins in Sepsis

Sepsis, a systemic inflammatory response disease, is the most severe complication of infection and a deadly disease. High mobility group proteins (HMGs) are non-histone nuclear proteins binding nucleosomes and regulate chromosome architecture and gene transcription, which act as a potent pro-inflammatory cytokine involved in the delayed endotoxin lethality and systemic inflammatory response. HMGs increase in serum and tissues during infection, especially in sepsis. A growing number of studies have demonstrated HMGs are not only cytokines which can mediate inflammation, but also potential therapeutic targets in sepsis. To reduce sepsis-related mortality, a better understanding of HMGs is essential. In this review, we described the structure and function of HMGs, summarized the definition, epidemiology and pathophysiology of sepsis, and discussed the HMGs-related mechanisms in sepsis from the perspectives of non-coding RNAs (microRNA, long non-coding RNA, circular RNA), programmed cell death (apoptosis, necroptosis and pyroptosis), drugs and other pathophysiological aspects to provide new targets and ideas for the diagnosis and treatment of sepsis.

Oxidized high mobility group B-1 enhances metastability of colorectal cancer via modification of mesenchymal stem/stromal cells

High mobility group box-1 (HMGB1) is known to be a chemotactic factor for mesenchymal stem/stromal cells (MSCs), but the effect of post-translational modification on its function is not clear. In this study, we hypothesized that differences in the oxidation state of HMGB1 would lead to differences in the function of MSCs in cancer. In human colorectal cancer, MSCs infiltrating into the stroma were correlated with liver metastasis and serum HMGB1. In animal models, oxidized HMGB1 mobilized 3-fold fewer MSCs to subcutaneous tumors compared to reduced HMGB1. Reduced HMGB1 inhibited proliferation of mouse bone marrow MSCs (BM-MSCs) and induced differentiation into osteoblasts and vascular pericytes, whereas oxidized HMGB1 promoted proliferation and increased stemness, and no differentiation was observed. When BM-MSCs pretreated with oxidized HMGB1 were co-cultured with syngeneic cancer cells, cell proliferation and stemness of cancer cells were increased, and tumorigenesis and drug resistance were promoted. In contrast, co-culture with reduced HMGB1-pretreated BM-MSCs did not enhance stemness. In an animal orthotopic transplantation colorectal cancer model, oxidized HMGB1, but not reduced HMGB1, promoted liver metastasis with intratumoral MSC chemotaxis. Thus, oxidized HMGB1 reprograms MSCs and promotes cancer malignancy. The oxidized HMGB1-MSC axis may be an important target for cancer therapy.

Immunogenic Cell Death, DAMPs and Prothymosin α as a Putative Anticancer Immune Response Biomarker

The new and increasingly studied concept of immunogenic cell death (ICD) revealed a previously unknown perspective of the various regulated cell death (RCD) modalities, elucidating their immunogenic properties and rendering obsolete the notion that immune stimulation is solely the outcome of necrosis. A distinct characteristic of ICD is the release of danger-associated molecular patterns (DAMPs) by dying and/or dead cells. Thus, several members of the DAMP family, such as the well-characterized heat shock proteins (HSPs) HSP70 and HSP90, the high-mobility group box 1 protein and calreticulin, and the thymic polypeptide prothymosin α (proTα) and its immunoreactive fragment proTα(100–109), are being studied as potential diagnostic tools and/or possible therapeutic agents. Here, we present the basic aspects and mechanisms of both ICD and other immunogenic RCD forms; denote the role of DAMPs in ICD; and further exploit the relevance of human proTα and proTα(100–109) in ICD, highlighting their possible clinical applications. Furthermore, we present the preliminary results of our in vitro studies, which show a direct correlation between the concentration of proTα/proTα(100–109) and the levels of cancer cell apoptosis, induced by anticancer agents and γ-radiation.

Physiological roles of hydrogen sulfide in mammalian cells, tissues and organs

H2S belongs to the class of molecules known as gasotransmitters, which also includes nitric oxide (NO) and carbon monoxide (CO). Three enzymes are recognized as endogenous sources of H2S in various cells and tissues: cystathionine g-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current article reviews the regulation of these enzymes as well as the pathways of their enzymatic and non-enzymatic degradation and elimination. The multiple interactions of H2S with other labile endogenous molecules (e.g. NO) and reactive oxygen species are also outlined. The various biological targets and signaling pathways are discussed, with special reference to H2S and oxidative posttranscriptional modification of proteins, the effect of H2S on channels and intracellular second messenger pathways, the regulation of gene transcription and translation and the regulation of cellular bioenergetics and metabolism. The pharmacological and molecular tools currently available to study H2S physiology are also reviewed, including their utility and limitations. In subsequent sections, the role of H2S in the regulation of various physiological and cellular functions is reviewed. The physiological role of H2S in various cell types and organ systems are overviewed. Finally, the role of H2S in the regulation of various organ functions is discussed as well as the characteristic bell-shaped biphasic effects of H2S. In addition, key pathophysiological aspects, debated areas, and future research and translational areas are identified A wide array of significant roles of H2S in the physiological regulation of all organ functions emerges from this review.

Progress in Assays of HMGB1 Levels in Human Plasma-The Potential Prognostic Value in COVID-19

Extracellular HMGB1 protein is known to induce inflammatory responses leading to an inflammatory storm. The outbreak of the Severe Acute Respiratory Syndrome COVID-19 due to the SARS-CoV-2 virus has resulted in a huge health concern worldwide. Recent data revealed that plasma/serum HMGB1 levels of patients suffering from inflammation-mediated disorders-such as COVID-19, cancer, and autoimmune disorders-correlate positively with disease severity and vice versa. A late release of HMGB1 in sepsis suggests the existence of a wide therapeutic window for treating sepsis. Rapid and accurate methods for the detection of HMGB1 levels in plasma/serum are, therefore, of great importance for monitoring the occurrence, treatment success, and survival prediction of patients with inflammation-mediated diseases. In this review, we briefly explain the role of HMGB1 in the cell, and particularly the involvement of extracellular HMGB1 (released from the cells) in inflammation-mediated diseases, with an emphasis on COVID-19. The current assays to measure HMGB1 levels in human plasma-Western blotting, ELISA, EMSA, and a new approach based on electrochemical immunosensors, including some of our preliminary results-are presented and thoroughly discussed.

HMGB1-mediated autophagy promotes gefitinib resistance in human non-small cell lung cancer

Non-small cell lung cancer (NSCLC) ranks the first in incidence and mortality among malignant tumors in China. Molecular targeted therapies such as gefitinib, an oral inhibitor of the epidermal growth factor receptor tyrosine kinase, have shown significant benefits in patients with advanced NSCLC. However, most patients have unsatisfactory outcomes due to the development of drug resistance, and there is an urgent need to better understand the pathways involved in the resistance mechanisms. In this study, we found that HMGB1 is highly expressed in drug-resistant cells and confers to gefitinib resistance in NSCLC cells via activating autophagy process. Gefitinib upregulates HMGB1 expression in time-dependent and dose-dependent manners in human NSCLC cells. RNA interference-mediated knockdown of HMGB1 reduces PC9GR cell viability, induces apoptosis, and partially restores gefitinib sensitivity. Mechanistic analyses indicate that elevated HMGB1 expression contributes to gefitinib resistance by inducing autophagy. Thus, our results suggest that HMGB1 is an autophagy regulator and plays a key role in gefitinib resistance of NSCLC.

Irradiation immunity interactions

The immune system can influence cancer development by both impeding and/or facilitating tumour growth and spread. A better understanding of this complex relationship is fundamental to optimise current and future cancer therapeutic strategies. Although typically regarded as a localised and immunosuppressive anti‐cancer treatment modality, radiation therapy has been associated with generating profound systemic effects beyond the intended target volume. These systemic effects are immune‐driven suggesting radiation therapy can enhance anti‐tumour immunosurveillance in some instances. In this review, we summarise how radiation therapy can positively and negatively affect local and systemic anti‐tumour immune responses, how co‐administration of immunotherapy with radiation therapy may help promote anti‐tumour immunity, and how the use of immune biomarkers may help steer radiation therapy‐immunotherapy personalisation to optimise clinical outcomes.

Insights into the Impact of Gold Nanoclusters Au10SG10 on Human Microglia

The purpose of the current study is to uncover the impact of small liganded gold nanoclusters with 10 gold atoms and 10 glutathione ligands (Au₁₀SG₁₀) on several biomarkers in human microglia. We established the links connecting the atomically precise structure of Au₁₀SG₁₀ with their properties and changes in several biomolecules under oxidative stress. Au₁₀SG₁₀ caused the loss of mitochondrial metabolic activity, increased lipid peroxidation and translocation of an alarmin molecule, high mobility group box 1 (HMGB1), from the nucleus to the cytosol. Molecular modeling provided an insight into the location of amino acid interaction sites with Au₁₀SG₁₀ and the nature of bonds participating in these interactions. We show that Au₁₀SG₁₀ can bind directly to the defined sites of reduced, oxidized, and acetylated HMGB1. Further studies with similar complementary approaches merging live-cell analyses, determination of biomarkers, and cell functions could lead to optimized gold nanoclusters best suited for diagnostic and bioimaging purposes in neuroscience.

Inhibition of HMGB1 Ameliorates the Maternal-Fetal Interface Destruction in Unexplained Recurrent Spontaneous Abortion by Suppressing Pyroptosis Activation

Recurrent spontaneous abortion (RSA) is a common complication of pregnancy that affects the physical and mental health of pregnant women, and approximately 50% of the mechanisms are unclear. Our previous studies have found that high mobility group box 1 (HMGB1) molecules are highly expressed at the maternal-fetal interface of unexplained recurrent spontaneous abortion (URSA) patients. The purpose of this study was to further detect the expression of HMGB1 and pyroptosis in decidual tissue of URSA patients, and explore the potential mechanism of the protective role of HMGB1 in URSA patients and mouse model. The decidua tissues of 75 URSA patients and 75 women who actively terminated pregnancy were collected, and URSA mouse models were established and treated with HMGB1 inhibitor-aspirin. The expression of HMGB1, and their receptors (RAGE, TLR2, TLR4), pyroptosis-associated proteins (NLRP-3, caspase-1, GSDMD) and NF-κB was examined at the maternal-fetal interface of human and mouse. Our study found that HMGB1, NLRP-3, Caspase-1, GSDMD, RAGE, TLR2 and TLR4 were highly expressed and NF-κB signaling pathway were activated in the decidua tissue of URSA group. Moreover, immune cell disorder and co-localization of HMGB1 and macrophages were found at the maternal-fetal interface of URSA mice. However, HMGB1, TLR2, TLR4, NF-κB, and pyroptosis-associated proteins can be down-regulated by administering low-dose aspirin. These data may indicate that highly expressed HMGB1 was actively secreted by macrophages and then activated pyroptosis through the TLR2/TLR4-NF-κB pathway to cause aseptic inflammation, leading to the occurrence and development of URSA. Moreover, low-dose aspirin can reduce HMGB1 protein levels of serum and decidual in URSA.

Low-dose aspirin protects unexplained recurrent spontaneous abortion via downregulation of HMGB1 inflammation activation

BACKGROUND

High mobility group box protein 1 (HMGB1) is considered as a kind of sterile inflammatory mediators, which is an overexpression in patients with unexplained recurrent spontaneous abortion (URSA). Specific targeting effect of aspirin on HMGB1 has been revealed. Our previous studies have explored the application of HMGB1 as a therapeutic target of aspirin in URSA disease of mice model and human, but the dynamic process of aspirin downregulating HMGB1 concentration has not been demonstrated.

METHODS

From December 2018 to November 2020, women with URSA (n = 91) and control women (n = 90) with no history of recurrent abortion or adverse pregnancy were included in the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University. ELISA was applied to detect the concentrations of HMGB1 and IFN-γ in the peripheral blood. Thirty-one URSA patients were monitored for low-dose aspirin treatment (2 and 4 weeks), the changes of HMGB1 and IFN-γ concentrations in peripheral blood of URSA patients before and after using aspirin were compared, and pregnancy outcomes after aspirin treatment were followed up.

RESULTS

The levels of HMGB1 in peripheral blood were significantly higher in URSA patients compared with controls, decreasing trends of HMGB1 and IFN-γ concentrations in plasma of URSA patients were observed after treatment with low-dose aspirin continuously, and the expression of HMGB1 was positively correlated with IFN-γ. There were no birth abnormalities in the babies of the URSA patients treated with aspirin.

CONCLUSIONS

High levels of HMGB1 may be one of the pathogenesis of URSA. Low-dose aspirin may provide protective effect on the HMGB1-triggered URSA.

Heme Oxygenase-1/High Mobility Group Box 1 Pathway May Have a Possible Role in COVID-19 ARDS (Acute Respiratory Distress Syndrome): A Pilot Histological Study

COVID-19 is a pandemic disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The persistent and excessive inflammatory response can build up a clinical picture that is difficult to manage and potentially fatal. Potent activators of inflammatory phenomena are damage-associated molecular patterns (DAMPs) and, in particular, the high-mobility group box 1 (HMGB1). HMGB1 is an intranuclear protein that is either passively released during hypoxia-related necrosis or actively released by macrophages. Heme oxygenase (HO-1) has an anti-inflammatory effect by inhibiting HMGB1, which could be a therapeutic target to reduce COVID-19 inflammation. In our study, we evaluated CD3, CD4, CD8, HMGB1 and HO-1 in the COVID-19 lung and correlated it to clinical data.

Increased circulating levels of High Mobility Group Box 1 (HMGB1) in acute-phase Chikungunya virus infection: Potential disease biomarker

BACKGROUND

Chikungunya virus (CHIKV) causes a febrile syndrome with intense and debilitating arthralgia that can persist for several months or years after complete virus clearance. As there is no specific antiviral treatment or vaccine against CHIKV, identification of serological markers that help clinical management of CHIKV patients is urgent. The High Mobility Group Box 1 (HMGB1) protein is secreted to extracellular milieu and triggers an intense inflammatory process by inducing the overexpression of pro-inflammatory cytokines. HMGB1 plays an important role in several virus diseases as well as in rheumatoid arthritis.

OBJECTIVES

This study focus on the investigation of HMGB1 serum levels in a sera panel from CHIKV-infected patients in an attempt to assess its potential as a biomarker for chikungunya clinical management.

STUDY DESIGN

Eighty CHIKV-positive samples and 32 samples from healthy donors were subjected to a quantitative HMGB1 ELISA assay to assess the HMGB1 circulating levels.

RESULTS

HMGB1 levels were significantly higher in CHIKV-positive samples (516.12 ng/mL, SEM ± 48.83 ng/mL) compared to negative control (31.20 ng/mL, SEM ± 3.24 ng/mL, p < 0.0001). Circulating levels of HMGB1 persisted elevated during the whole acute-phase of disease and correlated with virus titer (p < 0.05).

CONCLUSIONS

The present study is the first to describe increased serum levels of HMGB1 in CHIKV infection and its positive correlation with virus titer, suggesting its potential use as a biomarker for diagnosis and treatment of chikungunya fever.

[Aloin inhibits lactate-induced proliferation and migration of gastric cancer cells by downregulating HMGB1 expression]

OBJECTIVE

To assess the inhibitory effects of aloin on lactate-induced gastric proliferation and migration of cancer cells and explore the underlying molecular mechanism.

METHODS

Gastric cancer BGC-823 cells were treated with aloin, lactate or the combination of lactate and different doses of aloin. EdU assay was used to detect the proliferation of BGC-823 cells, and colony formation ability of the cells was evaluated with colony forming assay; wound healing and Transwell assays were used to detect the changes in migration ability of the treated cells. The expression levels of cyclin D1, cyclin E1, PCNA, N-cadherin, E-cadherin, MMP-2, MMP-9 and HMGB1 were determined using Western blotting, and ELISA was performed to detect HMGB1 release. HMGB1 expression was knocked down in BGC-823 cells using RNA interference technique, and the effects of HMGB1 knockdown on proliferation and migration of the cells stimulated with lactate for 24 h were examined using EdU and wound healing assays.

RESULTS

Aloin treatment significantly inhibited lactate-induced proliferation of gastric cancer cells, lowered the colony forming ability of lactate-treated cells, and suppressed lactate-induced migration of the cells. Treatment with lactate obviously up-regulated the expressions of cyclin D1, cyclin E1, PCNA, N-cadherin, MMP-2, MMP-9 and HMGB1, which were significantly inhibited by aloin; aloin significantly reversed inhibition of E-cadherin and blocked the release of HMGB1 in lactate-treated cells. BGC-823 cells with HMGB1 knockdown, as compared with the cells transfected with the negative control plasmid, showed significantly lowered proliferation and migration abilities following lactate treatment.

CONCLUSION

Aloin inhibits lactate-induced proliferation and migration of gastric cancer cells by down-regulating the expression and release of HMGB1 and the expressions of proliferation- and migration-related proteins.