High Expression Of High Mobility Group Box 1 Research Articles

HMGB1 enhances the migratory and invasive abilities of A2780/DDP cells by facilitating epithelial to mesenchymal transition via GSK‑3β.

The aim of the present study was to investigate the impact and mechanism of high mobility group box 1 (HMGB1) on the regulation of cell migration and invasion in A2780/DDP cisplatin-resistant ovarian cancer cells. After transfecting small interfering (si)RNA-HMGB1 into A2780/DDP cells, Transwell migration and invasion assays were conducted to assess alterations in the cell migratory and invasive abilities. Additionally, western blotting analyses were performed to examine changes in HMGB1, phosphorylated (p)-GSK-3β, GSK-3β, E-cadherin and vimentin expression levels. The results of the present study demonstrated that the migratory and invasive abilities of A2780/DDP cells were significantly higher compared with those of A2780 cells. Additionally, the expression levels of HMGB1, p-GSK-3β and the mesenchymal phenotype marker, vimentin, in A2780/DDP cells were significantly elevated relative to the levels in A2780 cells. Conversely, the expression level of the epithelial phenotype marker, E-cadherin, was markedly decreased compared with that in A2780 cells. Following transfection of A2780/DDP cells with siRNA-HMGB1, there was a significant reduction in the rate of cell migration and invasion. Simultaneously, the expression levels of HMGB1, p-GSK-3β and vimentin were downregulated while the level of E-cadherin was upregulated. It was therefore concluded that the high expression of HMGB1 in A2780/DDP cells enhanced the cell migration and invasion abilities by facilitating epithelial to mesenchymal transition via GSK-3β.

High-Mobility Group Box 1 Overexpression Predicts a Poor Prognosis and Promotes Epithelial-Mesenchymal Transition in Gastric Cancer by Activating TLR4/NF-κB Signaling

Introduction: The molecular mechanism of high-mobility group box 1 (HMGB1) promoting the epithelial-mesenchymal transition (EMT) of gastric cancer (GC) has not been known well. This study aimed to explore the clinical effects of HMGB1 expression levels on the clinicopathological characteristics of patients with GC and to uncover the potential molecular mechanism which promotes tumor progression. Methods: The expression levels of HMGB1 in 125 patients with GC were detected by immunohistochemistry and Western blotting. Univariate and multivariate analyses were performed to evaluate the relationship between HMGB1 expression and clinical characteristics of patients with GC. Stable overexpression (over-HMGB1) and knockdown (sh-HMGB1) GC cell lines (AGS and MKN-45) were used to determine the effects of HMGB1 on the activation of TLR4/NF-κB signaling. Differences were considered statistically significant at p < 0.05 in two sides. Results: HMGB1 is highly expressed in GC tissues and cell lines. High HMGB1 expression (HR = 1.89, 95% CI: 1.44–2.39, p = 0.001) was an independent risk factor for overall survival in patients with GC. Downregulation of HMGB1 resulted in downregulation of TLR4 and NF-κB subunit (p-p65 and p-IκBα) expression, whereas the upregulated expression of HMGB1 led to increased expression of TLR4 and NF-κB subunits. Overexpression of HMGB1 promotes the upregulation of EMT-TF expression, which enhances the proliferation and migration abilities of GC cell lines. Conclusion: HMGB1 is highly expressed in GC tissues and is associated with a poorer prognosis in patients with GC. HMGB1 activates the TLR4/NF-κB signaling pathway to promote EMT progression in GC cell lines. HMGB1 may be a critical molecule in prognosis prediction and a therapeutic target for patients with GC.

A pan-cancer analysis of high mobility group box 1 and its role in human tumorigenesis

Understanding the specific and co-driving mechanisms of carcinogenesis in human tumors is indispensable for cancer research and can guide the development of effective treatment methods for tumors. High mobility group box 1 (HMGB1) participates in a variety of physiological processes of the body and has an inseparable relationship with tumors. In this study, The Cancer Genome Atlas, Gene Expression Omnibus database, Human Protein Atlas, and bioinformatic tools were used to conduct pan-cancer analysis of HMGB1 in various cancers so as to elucidate its role in human tumorigenesis. We analyzed and evaluated the expression of HMGB1 in tumors, and discovered that overexpression of HMGB1 usually indicated poor overall survival of adrenocortical carcinoma (P &lt; 0.01) and lung adenocarcinoma (LUAD) (P &lt; 0.05). High HMGB1 expression is also associated with unfavorable disease-free survival for patients with adrenocortical carcinoma (P &lt; 0.001), cervical squamous cell carcinoma and endocervical adenocarcinoma (P &lt; 0.01), head and neck squamous cell carcinoma (P &lt; 0.05), LUAD (P &lt; 0.05), and sarcoma (P &lt; 0.05). The potential mechanism of HMGB1-mediated tumorigenesis is also discussed. In conclusion, our pan-cancer analysis offers a comprehensive description of the carcinogenic roles of HMGB1 in a variety of human cancers.

Irradiation-induced exosomal HMGB1 to confer radioresistance via the PI3K/AKT/FOXO3A signaling pathway in ESCC

BackgroundRadioresistance is a major cause of treatment failure in esophageal squamous cell carcinoma (ESCC) radiotherapy, and the underlying mechanisms of radioresistance are still unclear. Irradiation (IR) stimulates changes in tumor-derived exosome contents, which can be taken up by recipient cells, playing an important role in the proliferation, cell cycle and apoptosis of recipient cells. This study investigated the effect of IR-induced exosomal high mobility group box 1 (HMGB1) on radioresistance in ESCC cells.MethodsPlasma exosomes were isolated from 21 ESCC patients and 24 healthy volunteers, and the expression of HMGB1 was examined. Then, the therapeutic effect of radiotherapy was analyzed according to the different expression levels of plasma exosomal HMGB1 in ESCC patients. The uptake of exosomes by recipient cells was verified by immunofluorescence staining, and the localization of exosomes and HMGB1 in cells before and after IR was evaluated. The effects of IR-induced exosomes on cell proliferation, invasion, apoptosis, cell cycle distribution and radioresistance after HMGB1 knockdown were verified. Moreover, western blotting was used to measure changes in the expression of cyclin B1, CDK1, Bax, Bcl2, phosphorylated histone H2AX and the PI3K/AKT/FOXO3A pathway in the HMGB1-knockdown exosome group and the negative control group.ResultsThe expression of HMGB1 in ESCC plasma exosomes was significantly increased compared with that in healthy volunteers, and high expression of HMGB1 in plasma exosomes was associated with radioresistance (P = 0.016). IR-induced the release of exosomal HMGB1 and promoted proliferation and radioresistance in recipient cells, with a sensitization enhancement ratio (SER) of 0.906 and 0.919, respectively. In addition, IR-induced exosomal HMGB1 promotes G2/M phase arrest by regulating the proteins cyclin B1 and CDK1, cooperating with the proteins Bax and Bcl2 to reduce the apoptosis rate through the PI3K/AKT/FOXO3A signaling pathway, and participated in IR-induced DNA damage repair through γH2AX.ConclusionThese findings indicate that high expression of plasma exosomal HMGB1 is associated with an adverse radiotherapy response. IR-induced exosomal HMGB1 enhances the radioresistance of ESCC cells.

Jieduan-Niwan Formula Ameliorates Oxidative Stress and Apoptosis in Acute-on-Chronic Liver Failure by Suppressing HMGB1/TLR-4/NF-κB Signaling Pathway: A Study In Vivo and In Vitro.

Jieduan-Niwan (JDNW) formula is a traditional Chinese medicine compound created by the famous Chinese medicine expert Professor Qian Ying, and has been used clinically for decades to treat acute-on-chronic liver failure (ACLF) and exhibits remarkable efficacy. However, the exact mechanism remains to be discovered. As an important hepatocyte damage-associated molecular patterns (DAMP) factor, high mobility group box 1 (HMGB1) is a potential therapeutic target as an accelerator of ACLF in the pathogenesis. Therefore, the present study investigated whether JDNW inhibits the overexpression and cytoplasmic translocation of HMGB1 in ACLF liver tissue and alleviates its mediated oxidative stress and apoptosis. In vivo, an immune-induced ACLF rat model was established, and then treated with JDNW for 5, 10, and 15 d. The results showed that a large number of cytoplasmic translocations of HMGB1 occurred in the ACLF group. And there was an increase in the expression of HMGB1 in the M-5 d group. After the intervention of JDNW, the overexpression and translocation of HMGB1 were inhibited. In vitro, D-GaLN caused an increase in the expression and translocation of HMGB1 in L02 cells. Similar to the inhibitor of HMGB1, JDNW serum alleviated this kind of increase. Further tests showed that JDNW attenuated ACLF-related oxidative stress and apoptosis, and the inhibition was associated with the regulation of TLR-4/NF-κB signaling pathway. In conclusion, our present findings suggest that the therapeutic effect of JDNW on ACLF was associated with the inhibition of high expression and cytoplasmic translocation of HMGB1 during the acute injury phase, thus, attenuating oxidative stress injury and apoptosis induced by HMGB1/TLR-4/NF-κB pathway.

Genetic alterations, RNA expression profiling and DNA methylation of HMGB1 in malignancies.

The high mobility group box 1 (HMGB1) is a potential biomarker and therapeutic target in various human diseases. However, a systematic, comprehensive pan‐cancer analysis of HMGB1 in human cancers remains to be reported. This study analysed the genetic alteration, RNA expression profiling and DNA methylation of HMGB1 in more than 30 types of tumours. It is worth noting that HMGB1 is overexpressed in malignant tissues, including lymphoid neoplasm diffuse large B‐cell lymphoma (DLBC), pancreatic adenocarcinoma (PAAD) and thymoma (THYM). Interestingly, there is a positive correlation between the high expression of HMGB1 and the high survival prognosis of THYM. Finally, this study comprehensively evaluates the genetic variation of HMGB1 in human malignant tumours. As a prospective biomarker of COVID‐19, the role that HMGB1 plays in THYM is highlighted.

Peritumoral B cells drive proangiogenic responses in HMGB1-enriched esophageal squamous cell carcinoma

Several B-cell subsets with distinct functions and polarized cytokine profiles that extend beyond antibody production have been reported in different cancers. Here we have demonstrated that proliferating B cells were predominantly found in the peritumoral region of esophageal squamous cell carcinoma (ESCC). These B cells were enriched in tumor nests with high expression of high-mobility group box 1 (HMGB1). High densities of peritumoral proliferating B cells and concomitantly high intratumoral HMGB1 expression showed improved prognostic significance, surpassing prognostic stratification of ESCC patients based on HMGB1 positivity alone. This striking association led us to set up models to test whether cancer-derived HMGB1 could shape tumor microenvironment via modulation on B cells. Overexpression of HMGB1 in ESCC cell lines (KYSE510 and EC18) enhanced proliferation and migration of B cells. Transcriptomic analysis showed that migratory B cells exhibited high enrichment of proangiogenic genes. VEGF expression in proliferating B cells was induced upon co-culture of HMGB1-overexpressing tumor cells and B cells. Secretome array profiling of conditioned media (CM) from the co-culture revealed rich expression of proangiogenic proteins. Consequently, incubation of human umbilical vein endothelial cells with CM promoted angiogenesis in tube formation and migration assays. HMGB1 inhibitor, glycyrrhizin, abolishes all the observed proangiogenic phenotypes. Finally, co-injection of B cells and CM with HMGB1-overexpressing tumor cells, but not with glycyrrhizin, significantly enhanced tumor growth associated with increased microvascular density in ESCC xenograft mice model. Our results indicate that cancer-derived HMGB1 elevates angiogenesis in ESCC by shifting the balance toward proangiogenic signals in proliferating B cells.

Identification of High-Mobility Group Box 1 (HMGB1) Expression as a Potential Predictor of Rejection and Poor Prognosis After Liver Transplantation.

BackgroundAcute cellular rejection (ACR) frequently occurs after liver transplantation (LT) and can result in permanent damage of the liver allograft. Specific and sensitive biomarkers for predicting and monitoring ACR are vital for guiding post-transplantation care. In the present study, we aimed to investigate the function of high-mobility group box 1 (HMGB1) in predicting ACR and prognosis after LT.Material/MethodsA total of 113 LT recipients were enrolled in the study, including 62 patients in an ACR group and 51 patients in a non-rejection group. Using tissues from the 113 patients, HMGB1 expression was examined by immunohistochemistry, and the total score for HMGB1 expression was calculated by multiplying the percentage of immunoreactive cells score and the staining intensity score. We then analyzed the association between HMGB1 expression and clinical features. Finally, the function of HMGB1 in predicting the prognosis of LT was determined using Kaplan-Meier (K-M) survival and Cox multivariate analyses.ResultsImmunohistochemical staining results demonstrated that the expression of HMGB1 was significantly increased in the ACR group, compared with that in the non-rejection group (P<0.05). Clinical characteristic analysis revealed that high HMGB1 levels were related to ACR (P<0.05). Moreover, K-M survival analysis showed that patients with high HMGB1 expression displayed poorer prognosis (P<0.05). Cox multivariate analysis demonstrated that HMGB1 was an independent prognostic predictor for post-LT survival (odds ratio, 3.283; P=0.008).ConclusionsLT recipients’ HMGB1 levels may be a useful and noninvasive biomarker for the prediction of ACR and prognosis after LT.

Upregulated HMGB1 levels in maternal–fetal interface of patients with unexplained recurrent spontaneous abortion from different sources

Objective To investigate the expression and sources of high mobility group box 1 (HMGB1) protein in the maternal–fetal interface of patients with unexplained recurrent spontaneous abortion (URSA), and further to verify the role of HMGB1 in the etiology of URSA. Methods 55 women at early pregnancy with URSA and 55 women undergoing selective termination of normal early pregnancy as control were included. The abortion tissues including villi and decidua were collected. The expression of HMGB1, CD45, CK7, and vimentin in abortion tissues was detected, and the localization and sources of HMGB1 were analyzed. Results Infiltrating immune cells and expression of HMGB1 were significantly increased in villi and decidua in URSA group compared with those in the control group. In the URSA group, HMGB1 was colocalized with the CD45-labeled immune cells, and it was more obvious in decidua than in villi; in addition, HMGB1 was colocalized with the vimentin-labeled decidual stromal cells, but not with the CK7- labeled villous epithelial cells. Conclusion High expression of HMGB1 in the maternal–fetal interface in URSA patients was actively secreted by the infiltrating immune cells, and decidual stromal cells may passively release HMGB1 during necrosis.

HMGB1 is a key factor for tamoxifen resistance and has the potential to predict the efficacy of CDK4/6 inhibitors in breast cancer.

Breast cancer is the leading cause of cancer death in women. Hormone‐receptor‐positive breast cancer (HR + BC) is the most common pathological type of breast cancer, of which the main treatment method is endocrine therapy. Unfortunately, primary or acquired drug resistance greatly limits its efficacy. In recent years, the newly launched CDK4/6 inhibitors could effectively reverse endocrine resistance in breast cancer. However, considering their expensive price and side effects, it is particularly important to find out effective biomarkers and screen sensitive patients. Here, we found through bioinformatics analysis that high mobility group box 1 (HMGB1) expression increased in endocrine‐resistant HR + BC. In clinical specimens, the higher expression of HMGB1 was associated with shorter progression‐free survival (PFS) for HR + BC patients with endocrine therapy after surgery. For endocrine‐resistant breast cancer, compared with HMGB1‐negative patients, HMGB1‐positive patients who received CDK4/6 inhibitors treatment benefited more in PFS. Moreover, we demonstrated that HMGB1 promoted tamoxifen resistance by combining with the Toll‐like receptor 4 (TLR4) and activating nuclear factor kappa B (NF‐κB) pathway. CDK4/6 inhibitors could downregulate the expression of HMGB1 and suppress the TLR4‐NF‐κB pathway, and in turn reverse tamoxifen resistance. These results illuminated the critical role of HMGB1 in the process of tamoxifen resistance, explained the mechanism of CDK4/6 inhibitors reversing tamoxifen resistance, and suggested the feasibility of HMGB1 as a potential biomarker for screening sensitive patients receiving CDK4/6 inhibitors.

MiR-451 Promotes Cell Apoptosis and Inhibits Autophagy in Pediatric Acute Myeloid Leukemia by Targeting HMGB1.

MiR-451 plays a tumor suppressive role in a variety of cancers. However, the function of miR-451 in acute myeloid leukemia (AML) has not been fully understood. Herein, we focused on the effect of miR-451 in pediatric AML and its regulatory mechanism. MiR-451 and high mobility group box 1 (HMGB1) levels were tested in bone marrow of pediatric AML patients and healthy controls, and in AML cells and HS-5 cells by qRT-PCR and Western blot analysis. HL-60 and THP-1 cells were treated with miR-451 mimics, pcDNA-HMGB1, and corresponding controls. The changes in apoptosis and autophagy were evaluated in miR-451 overexpressed AML cells with MTT and flow cytometry. The interaction between miR-451 and HMGB1 was determined by dual-luciferase reporter assay, qRT-PCR, and Western blot. After cells were co-transfected with pcDNA-HMGB1 and pc-DNA-ctrl, we investigated apoptosis and autophagy in miR-451 overexpressed cells perturbed by exogenous HMGB1 through MTT, flow cytometry, and Western blot. miR-451's role in drug sensitivity was further measured. Pediatric AML bone marrow and cell lines presented low expression of miR-451 coupled with high expression of HMGB1. HMGB1 was determined to be a functional target of miR-451. MiR-451 overexpression remarkably enhanced apoptosis and reduced autophagy in both AML cell lines, which was reversed by pcDNA-HMGB1 transfection. Additionally, exogenous miR-451 significantly enhanced the sensitivity of HL-60 cells to the chemotherapy drug As2O3. MiR-451 exerted a tumor suppressive effect in enhancing cell death and reducing autophagy of AML cells by targeting HMGB1. MiR-451 might be considered a candidate target for treating pediatric AML.

Expression profiles of HMGB1 on B-CLL related leukocytes contribute to prediction of relapse

BackgroundThe High Mobility Group Box 1 (HMGB1) is a nuclear protein that is frequently overexpressed in hematologic diseases and might be of relevance in immunogenic cancer control thus correlating with patients’ (pts.) prognosis in diseases such as acute myeloid, acute lymphatic and chronic lymphocytic leukemia. Materials and methodsExpression profiles of blasts from AML (n = 21), ALL (n = 16) and of B-lymphocytes of CLL (n = 9) pts. were analyzed for surface expression of HMGB1 using flow cytometry. Expression was quantified and correlated with clinically and prognostically relevant markers. ResultsExpression profiling of HMGB1 in blasts of AML and ALL subtypes did not show differences between primary vs. secondary disease development and gender related differences. In ALL pts. however, age groups at initial diagnosis between ≥20 vs. <20 years were compared and showed significant differences (≥20 vs. <20 years; 89% vs. 49%, p <0.05) with higher expression in higher age. In AML and CLL these differences were not visible. To evaluate the prognostic significance of HMGB1 expression, expression quantity was correlated with established and prognostic classification systems (in AML ELN, in ALL GMALL) and probability to relapse. No significant correlation was seen in these entities. However, when AML pts. were analyzed for remission rates after first anthracycline based induction therapy, in those who did not experience a complete remission significantly enhanced HMGB1 surface expression was seen (98 vs. 94%; p < 0.05; n = 20). Furthermore, for CLL it was shown that higher HMGB1 expression was found in pretreated patients with relapsed or/and refractory disease (1 vs. more relapses; 94 vs. 98%; p <0.05; n = 9). ConclusionHMGB1 is frequently expressed in hematologic malignancies. In this study it was shown that HMGB1 surface expression on AML blasts can be used as predictors for treatment response. In CLL it may be a marker for advanced disease. In order to implement this marker in FACS routine it could be a useful and practical tool for prognostic assessment and treatment planning.

MiR-103a-3p alleviates oxidative stress, apoptosis, and immune disorder in oxygen-glucose deprivation-treated BV2 microglial cells and rats with cerebral ischemia-reperfusion injury by targeting high mobility group box 1.

BackgroundCerebral ischemia-reperfusion injury (CI/R) is among the most common diseases affecting the central nervous system. Due to the poor efficacy and adverse side effects of the drugs used to treat CI/R in clinical trials, a new treatment strategy is urgently needed. In this study, we aimed to investigate whether miR-103a-3p alleviates CI/R in vivo and vitro and to explore the relevant mechanisms.MethodsBV2 microglial cells underwent oxygen-glucose deprivation (OGD) treatment to imitate the pathophysiology of CI/R in vitro. A middle cerebral artery occlusion (MCAO) rat model was established to imitate the pathophysiology of CI/R in vivo. The expression levels of miR-103a-3p and HMGB1 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, enzyme-linked immunosorbent assay (ELISA), and hematoxylin and eosin (H&E) and Nissl staining were used to evaluated apoptosis, oxidative stress, inflammatory response, and histopathology, respectively.ResultsOGD-stimulated BV2 microglial cells and brain tissues with CI/R had low expression of miR-103a-3p but high expression of high mobility group box 1 (HMGB1). As expected, miR-103a-3p and HMGB1 had a targeting relationship. Overexpression of HMGB1 enhanced the the levels of interleukin (IL)-1 beta, tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA), but reduced the content of superoxide dismutase (SOD), IL-4, and IL-10, in vitro. Moreover, high expression of HMGB1 aggravated the brain injury of the model rats, and increased the secretion of inflammatory factors, exacerbated oxidative stress, and further induced tissue apoptosis in the brain tissue. Importantly, these effects of HMGB1 overexpression were partly reversed by miR-103a-3p overexpression on HMGB1 interference.ConclusionsHMGB1 is targeted by miR-103a-3p, which may be a new strategy in the treatment of CI/R.

Involvement of HMGB1 in vemurafenib resistance in thyroid cancer cells harboring BRAF (V600E) mutation by regulating excessive autophagy.

Thyroid carcinoma is the most frequent endocrine malignancy with high occurrence of BRAFV600E mutations. Though targeted therapy by vemurafenib, a specific inhibitor for BRAFV600E, has achieved great advance in therapeutic landscape, resistance occurrence is still a clinical challenge. Here, we sought to elucidate the function of high mobility group box 1 (HMGB1) in vemurafenib resistance in thyroid cancer harboring BRAF mutation. The expression of HMGB1 in BRAF-mutant BCPAP and BRAF-wild CAL-62 cells were determined by qRT-PCR and western. Then, BCPAP cells were transfected with recombinant HMGB1 plasmids, and vemurafenib-resistant BCPAP-R cells were treated with si-HMGB1. The efficacy of HMGB1 on vemurafenib resistance was evaluated by detecting cell viability, apoptosis, and caspase-3 activity. In addition, the involvement of autophagy pathway was investigated. Lower expression of HMGB1 was observed in BRAF-mutant BCPAP cells that had high sensitivity to vemurafenib. Overexpression of HMGB1 attenuated BCPAP cell sensitivity to vemurafenib by increasing cell viability and decreasing cell apoptosis and caspase-3 activity. Intriguingly, higher expression of HMGB1 was confirmed in vemurafenib-resistant BCPAP-R cells. Moreover, knockdown of HMGB1 sensitized BCPAP-R cells to vemurafenib resistance. Mechanistically, vemurafenib exposure induced autophagy by enhancing LC3II, Beclin-1 expression, and reducing autophagy substrate p62 expression. Importantly, targeting HMGB1 suppressed vemurafenib-induced autophagy. Blocking autophagy pathway with its inhibitor 3-MA offset BCPAP-R cell resistance to vemurafenib. These findings highlight that HMGB1-mediated autophagy may account for vemurafenib resistance in thyroid cancer harboring BRAF mutation, implying a promising approach to overcome vemurafenib resistance in vemurafenib-mutant thyroid carcinomas.

HMGB1 upregulates NF-kB by inhibiting IKB-α and associates with diabetic retinopathy

AimsDiabetic retinopathy (DR) is the main cause of blindness in adults and investigating new therapeutic targets for DR is necessary. This study aimed to investigate the effect of high-mobility group box 1 (HMGB1) protein and its mechanism in diabetic retinopathy (DR) were investigated. Main methodsHuman retinal endothelial cells (HREC) were uesd for chip-seq. Sprague Dawley (SD) rats were randomly divided into control group, HMGB1 group, diabetes mellitus (DM) combined with HMGB1 siRNA group, and DM group. Next, eyeballs were removed and retinas were detached for western blot. The DM model of cell was built by increasing the glucose concentration in cell culture medium. The regulation of HMGB1 was achieved by short hairpin (sh)-HMGB1 transfection, then, the transfected cells were harvested for luciferase assay, western blot and qRT-PCR analyses as well as proliferation and apoptosis detection. Key findingsChip-seq and luciferase assay showed the possible transcription factor functions of HMGB1 and IKB-α was one of the HMGB1 binding sites. In vivo and in vitro results indicated high expression of HMGB1 and NF-kB and low expression of IKB-α in DR and the expression of IKB-α and NF-kB was regulated by HMGB1. Moreover, cell assays showed that HMGB1 inhibited cell proliferation and promoted apoptosis. SignificanceThe results from the present study showed that HMGB1 may be involved in the pathogenesis of DR as a transcription factor through NF-kB pathway. Therefore, blockade of HMGB1 may be a new method for the treatment of DR.

Neutrophil extracellular traps are a source of extracellular HMGB1 in lupus nephritis: associations with clinical and histopathological features.

This study aimed to analyze the expression of the high mobility group box-1 (HMGB1) protein in neutrophil extracellular traps (NETs) of patients with lupus nephritis (LN) and its association with clinical and histopathological features of the disease. Twenty-three patients with biopsy-confirmed LN and 14 systemic lupus erythematosus (SLE) patients with active disease (SLE Disease Activity Index (SLEDAI) score ≥ 6) and no evidence of LN were included. Clinical and laboratory features were recorded. NETs and the expression of HMGB1 were assessed by confocal microscopy, and serum HMGB1 levels were measured by ELISA. In comparison to patients without kidney disease, patients with LN had a higher expression of HMGB1 in spontaneous (57 vs. 30.4; p = 0.027) and lipopolysaccharide (LPS)-induced (55.8 vs. 24.9; p = 0.005) NETs. We found a positive correlation between serum HMGB1 and the expression of HMGB1 in LPS-induced NETs (r = 0.447, p = 0.017). The expression of HMGB1 in spontaneous NETs correlated with SLEDAI score (r = 0.514, p = 0.001), anti-dsDNA antibodies (r = 0.467, p = 0.004), the rate of glomerular filtration descent (r = 0.543, p = 0.001), and diverse histopathological components of active nephritis in the kidney biopsy, such as the activity index (r = 0.581, p = 0.004), fibrinoid necrosis (r = 0.603, p = 0.002), and cellular crescents (r = 0.486, p = 0.019). In patients with SLE, NETs are a source of extracellular HMGB1. The expression of HMGB1 in NETs is higher among patients with LN, which correlates with clinical and histopathological features of active nephritis and suggest a possible role of this alarmin in the pathophysiology of kidney damage in SLE.

Antifibrotic Effects of High-Mobility Group Box 1 Protein Inhibitor (Glycyrrhizin) on Keloid Fibroblasts and Keloid Spheroids through Reduction of Autophagy and Induction of Apoptosis

Overabundance of extracellular matrix resulting from hyperproliferation of keloid fibroblasts (KFs) and dysregulation of apoptosis represents the main pathophysiology underlying keloids. High-mobility group box 1 (HMGB1) plays important roles in the regulation of cellular death. Suppression of HMGB1 inhibits autophagy while increasing apoptosis. Suppression of HMGB1 with glycyrrhizin has therapeutic benefits in fibrotic diseases. In this study, we explored the possible involvement of autophagy and HMGB1 as a cell death regulator in keloid pathogenesis. We have highlighted the potential utility of glycyrrhizin as an antifibrotic agent via regulation of the aberrant balance between autophagy and apoptosis in keloids. Higher HMGB1 expression and enhanced autophagy were observed in keloids. The proliferation of KFs was decreased following glycyrrhizin treatment. While apoptosis was enhanced in keloids after glycyrrhizin treatment, autophagy was significantly reduced. The expressions of ERK1/2, Akt, and NF-κB, were enhanced in HMGB1-teated fibroblasts, but decreased following glycyrrhizin treatment. The expression of extracellular matrix (ECM) components was reduced in glycyrrhizin-treated keloids. TGF-β, Smad2/3, ERK1/2, and HMGB1 were decreased in glycyrrhizin-treated keloids. Treatment with the autophagy inhibitor 3-MA resulted in a decrease of autophagy markers and collagen in the TGF-β-treated fibroblasts. The results indicated that autophagy plays an important role in the pathogenesis of keloids. Because glycyrrhizin appears to reduce ECM and downregulate autophagy in keloids, its potential use for treatment of keloids is indicated.

High-Mobility Group Box 1 expression predicts survival of patients after resection of adenocarcinoma of the ampulla of Vater

BackgroundExpression of High-Mobility Group Box 1 (HMGB1), a multifunctional protein involved in DNA function as well as cell proliferation, inflammation, and the immune response, has been reported to be prognostic in several types of malignancies. However, the prognostic value of HMGB1 in ampullary cancer has not been studied.MethodsPatients with adenocarcinoma of the ampulla of Vater who underwent R0 resection with pancreaticoduodenectomy between 2001 and 2011 were included in the present multi-institutional study. The degree of HMGB1 expression was examined in each resected specimen by immunohistochemical staining.ResultsA total of 101 patients were enrolled of which, 79 patients were eligible. High expression of HMGB1 was observed in 31 (39%) patients. Blood loss, transfusion, tumor stage, nodal status, and HMGB1 expression were identified as predictors with univariate analysis. Multivariate analysis showed that transfusion, lymph-node metastasis, and high HMGB1 expression were independent predictors of poor overall survival. Subgroup analysis showed that high HMGB1 expression was predictive, especially in patients who did not receive adjuvant chemotherapy.ConclusionsHigh HMGB1 expression is an independent predictor of poor prognosis in patients with adenocarcinoma of the ampulla of Vater not treated with adjuvant chemotherapy.

Unexpected inflammation in the sympathetic ganglia in thromboangiitis obliterans: more likely sterile or infectious induced inflammation?

IntroductionThe aim of this study was to determine if the inflammation of the sympathetic ganglia (SG) in thromboangiitis obliterans (TAO) is induced by an infectious pathogen inside or if it is a reactive sterile inflammation.MethodsFor the purpose of this study, the gene expression of high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), toll-like receptor 9 (TLR9), and the receptor for advanced glycation end-products (RAGE) were evaluated on the complementary DNA (cDNA) of the SG tissues of 24 TAO patients and two controls with hyperhidrosis by real-time polymerase chain reaction (PCR) and analysed by the Pfaffl method.ResultsThe gene expression of HMGB1 and TLR9 increased by about 25- and 2-fold changes in the SG of the TAO patients, respectively. However, there was no change in the gene expression of TLR4 or RAGE.ConclusionIt appears that the inflammation in the SG of TAO patients is more likely a sterile inflammation, and its trigger may be mitochondrial DNA (mtDNA). Cadmium in cigarettes could be responsible for the induction of mtDNA release to the cell cytoplasm. In addition, the high expression of HMGB1 may play a role in the pathogenesis of TAO and may be responsible for both clinical manifestation of the disease and the imaging findings. Moreover, HMGB1 may be a target for treatment protocols for TAO. Further studies are highly recommended.

Increased dermal expression of chromatin-associated protein HMGB1 and concomitant T-cell expression of the DNA RAGE in patients with psoriasis vulgaris.

PurposePsoriasis vulgaris (PV) is an autoimmune-related chronic inflammatory disease of the skin, with both vascular and metabolic effects. Aggravating factors have been identified that initiate and maintain inflammation, including expression of Th1-, Th17-, and Th22-cell derived cytokines. Recently, we showed that the evolutionarily ancient and highly conserved damage-associated molecular pattern molecule “high mobility group box 1 (HMGB1)” is significantly increased in the serum of PV patients with disease progression and is decreased under standard therapies.Materials and methodsTo better understand the role of HMGB1 in the pathogenesis of PV, we recruited 22 untreated psoriatic patients with either mild or severe disease, defined by the Psoriasis Area Severity Index. We assessed HMGB1 and receptor for advanced glycation end products (RAGE) expression in the skin by immunohistochemistry and analyzed the immune-phenotype of Treg and Th17 cells by flow cytometry.ResultsWe found increased staining for HMGB1 in the dermis of psoriatic plaques in comparison to uninvolved skin of patients with PV. In addition, the major histocompatibility complex class III-encoded DNA and HMGB1 RAGE, induced by HMGB1, were highly expressed on psoriatic CD8+ T cells and CD4+ Treg. High expression of HMGB1 in the lesional skin was associated with even higher expression of its receptor, RAGE, on the cell surface of keratino-cytes in patients with severe PV.ConclusionThe presence of HMGB1 and RAGE signaling may impact orchestration of chronic inflammation in PV which might have implications for Treg and Th17 cells.