High Mobility Group Box 1 mRNA Research Articles

Ketamine delays progression of oxidative and damaged cataract through regulating HMGB-1/NF-κB in lens epithelial cells

Objective: Lens epithelial cell (LEC) membrane damage is one of the pathogenesis of cataract. High mobility group box-1 (HMGB-1) and nuclear factor-κB (NF-κB) play vital roles in a variety of diseases, such as inflammation. Ketamine has numerous pharmacological effects that can inhibit inflammation. However, its role in cataract rats LECs has not yet been elucidated.Materials and methods: LECs were isolated from SD rats and cultured in vitro. The cells were randomly divided into three groups, including the control group, cataract model group induced by H2O2, and ketamine group treated by 10 mM ketamine under H2O2 environment. LECs proliferation was assessed by MTT assay. LECs apoptosis was evaluated by Caspase-3 activity detection. NF-κB mRNA and protein expressions were tested by real-time PCR and Western blot. HMGB-1 expressions in cells and supernatant were detected by real-time PCR and ELISA. TNF-α and IL-1β secretions were detected by ELISA.Results: In H2O2 model group, the LECs proliferation was significantly inhibited, the caspase-3 activity significantly increased, HMGB-1 mRNA and secretion significantly enhanced, NF-κB mRNA and protein levels significantly elevated, compared to the Control group (p < .05). While the TNF-α and IL-1β secretions significantly up-regulated in H2O2 model group compared to the Control group (p < .05). Ketamine significantly promoted the LECs proliferation, significantly reduced the caspase-3 activity, and significantly declined the HMGB expression compared to H2O2 model group (p < .05). The NF-κB mRNA and protein levels were significantly decreased, TNF-α and IL-1β secretions were significantly decreased in the Ketamine group compared with the model group (p < .05).Conclusions: Ketamine delays the progression of oxidative and damaged cataract by regulating HMGB-1/NF-κB expression, inhibiting TNF-α, IL-1β, and apoptosis, and promoting cell proliferation.

Clinical Implication of the Relationship Between High Mobility Group Box-1 and Tumor Differentiation in Hepatocellular Carcinoma.

High mobility group box-1 (HMGB1) induces the release of proinflammatory cytokines and chemokines as a late-acting mediator of inflammation. Hepatocellular carcinoma (HCC) is a typical inflammation-related cancer. However, little is known about the relationship between HCC and HMGB1 and its receptor RAGE (receptor for advanced glycation end products). This study analyzes the clinicopathological relevance of HMGB1 expression level and the effect of HMGB1 expression on the characteristics of HCC. Samples from 75 HCC patients including 13 with positive hepatitis B surface antigen and 36 with hepatitis C antibody were studied. The expression of HMGB1 in paired cancer and non-cancerous tissues from patients with HCC was assessed using reverse-transcription polymerase chain reaction (RT-PCR) and western blotting. Quantitative RT-PCR data were analyzed in association with the clinicopathological factors of patients with HCC. The expression of HMGB1 mRNA in HCC was high in well-differentiated tumors, but declined as tumors dedifferentiated to moderately and poorly differentiated HCC. The levels of HMGB1 mRNA showed a negative correlation with the presence of portal invasion (p=0.005) and the rise of serum PIVKA-II (p=0.034). There was no clear correlation between HMGB1 expression and proliferation activity of HCC using Ki-67 staining. In HCC, HMGB1 expression level correlated inversely with tumor differentiation. The RAGE-HMGB1 interaction may play a greater role in the early stages of HCC tumorigenesis than during cancer development.

Profile of HMGB1 mRNA Expression and TLR4 Protein in BALB/c Mice Model Sterile Injury after Systemic Lidocaine Administration

High mobility group box 1 (HMGB1) is a cytokine proinflamation which contributes to inflammation. HMGB1 physically interacts with toll like receptor 4 (TLR4) to release macrophage cytokines. The aim of this study was to demonstrate the effectiveness of systemic lidocaine administration to inhibit the expression of HMGB1 mRNA and TLR4 protein in mice BALB/c mice with sterile injury. Material and Methods: Twenty adult male BALB/c mice were divided into lidocaine and control groups. A sterile injury is done by closed fracturing the left thigh bone of the mice. The lidocaine group was treated with 2 mg/kgBW lidocaine through tail vein injection after 4 h of sterile injury. The control group was given distilled water therapy as a substitute for lidocaine. Mice blood is extracted from the tail vein before trauma, 4 h after trauma, and 2 h after the administration of lidocaine and distilled water is complete.The HMGB1 mRNA expression was examined by quantitative real-time polymerase chain reaction (qPCR) while the TLR4 protein level was determined with enzyme-linked immunosorbent assay (ELISA) according to the manufacturer’s instructions. Result: The HMGB1 mRNA expression and TLR4 protein levels in BALB/c that sustained inflammation due to a sterile injury was significantly decreased in the lidocaine group (p < 0.00). Conclusion: Administration systemic 2 mg/kgBW of lidocaine is effectively inhibits HMGB1 mRNA and TLR4 protein in mice that sustain inflammation due to a sterile injury.

Dysregulation of tristetraprolin and human antigen R promotes gastric cancer progressions partly by upregulation of the high-mobility group box 1

Aberrant expression of ARE-binding proteins (ARE-BPs) plays an important role in several diseases, including cancer. Both tristetraprolin (TTP) and human antigen R (HuR) are important ARE-BPs and always play opposite roles in regulating target mRNAs. Our previous work has demonstrated that TTP expression is decreased in gastric cancer (GC). In this study, we reported that HuR was elevated in GC cell lines and gastric cancer patients and that decreased TTP expression partly contributed to the elevated HuR levels by regulating its mRNA turnover. We also observed that dysregulation of TTP and HuR elevated the high-mobility group box 1 (HMGB1) expression in different ways. HuR promoted HMGB1 expression at translational level, while TTP regulated HMGB1 mRNA turnover by destabilizing its mRNA. Increased HuR promoted cancer cell proliferation and the metastasis potential partly by HMGB1. Using immunohistochemistry, we observed that both positive cytoplasmic and high-expression of nuclear HuR were associated with poor pathologic features and survival of GC patients. In conclusion, this study demonstrated that dysregulation of the TTP and HuR plays an important role in GC. Moreover, high HuR nuclear expression or aberrant cytoplasmic distribution may serve as a predictor of poor survival.

Overexpression of high mobility group box 1 contributes to progressive clinicopathological features and poor prognosis of human bladder urothelial carcinoma.

BackgroundHigh mobility group box 1 (HMGB1), a versatile protein with intranuclear and extracellular functions, plays an important role in a variety of human cancers. However, the clinical/prognostic significance of HMGB1 expression in human bladder urothelial carcinoma (BUC) remains unclear. The aim of this study was to investigate the HMGB1 expression in human BUC with regard to its clinical and prognostic significance.Patients and methodsHMGB1 mRNA and protein expressions in tumor and paired normal bladder tissues were detected in 20 BUC cases by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. HMGB1 protein expression in 165 primary BUC tissues was evaluated by immunohistochemistry (IHC), and its correlations with clinicopathological characteristics and prognosis were also analyzed. Student’s t-test, χ2 test, Kaplan–Meier plots, and Cox proportional hazard regression model were performed to analyze the data.ResultsBy using qRT-PCR and Western blot, the upregulated expression of HMGB1 mRNA and protein was detected in BUC, compared with paired normal tissue (P<0.05). By using IHC, high HMGB1 expression was examined in 84 of 165 (51.0%) BUC cases. High HMGB1 expression was significantly correlated with poorer differentiation and higher T and N classification (all P<0.05). Univariate analysis showed that high HMGB1 expression was significantly associated with a shortened patients’ overall survival (OS) and disease-free survival (DFS; both P<0.001). In different subgroups of BUC patients, HMGB1 expression was a prognostic factor in patients with different histological grades or T classification (all P<0.05), pN− (both P<0.001) for OS and DFS, and pT1/pN− (P<0.05) for OS. HMGB1 expression, as well as pT and pN status, was an independent prognostic factor for both OS (P=0.001, hazard ratio [HR] =2.973, 95% confidence interval [CI] =1.550–5.704) and DFS (P<0.001, HR =3.019, 95% CI =1.902–4.792) in multivariate analysis.ConclusionOverexpression of HMGB1 may be a new independent molecular marker for the poor prognosis of patients with BUC.

MicroRNA-520a-3p suppresses non-small-cell lung carcinoma by inhibition of High Mobility Group Box 1 (HMGB1).

Currently, pathogenesis of non-small cell lung carcinoma (NSCLC) is still unknown and the treatment is far from ideal. Therefore, we investigated the effect of inhibiting microRNA-520a-3p in NSCLC cells. NCI-H157 cells were treated with microRNA-520a-3p analogs for 48 h, or microRNA-520a-3p analogs and its inhibitor, for a total of 48 h. Many tests were performed, including MTT, flow cytometry, wound healing assay and transwell assay. The tumor model was established, and HMGB1 mRNA was detected by RT-PCR. Protein levels of HMGB1, MMP-2, MMP-9, Bcl-2, Bax, and Caspase-3 were assessed by Western Blot. microRNA-520a-3p could significantly inhibit the proliferation, migration and invasion of NCI-H157 cells, inducing their apoptosis. microRNA-520a-3p inhibited tumor growth and decreased the mRNA and protein levels of HMGB1. Additionally, it decreased the Bcl-2/Bax ratio, MMP-2 and MMP-9 expression, and increased caspase-3 expression. microRNA-520a-3p exhibited an effective inhibition on NCI-H157 tumor growth likely by inhibiting HMGB1 expression.

Ketamine alleviates LPS induced lung injury by inhibiting HMGB1-RAGE level.

Inflammatory cytokines secretion is an important reason to promote lung tissue inflammation in acute lung injury (ALI). High mobility group box 1 (HMGB-1) and its receptor for advanced glycation end products (RAGEs) play a role in ALI. Ketamine can significantly alleviate ALI, whereas its specific mechanism has not been fully elucidated. A total of 60 male Wistar rats were equally randomly divided into three groups, including ALI group which was established by 10 mg/kg LPS femoral vein injection, ketamine group which was constructed by 50 mg/kg ketamine femoral vein injection based on ALI model, and control group. Blood gas analysis was applied to detect arterial blood oxygen partial pressure (PaO2) and pH. Lung tissue wet/dry weight ratio (W/D), myeloperoxidase (MPO) and superoxide dismutase (SOD) activity were detected. Real-time PCR and ELISA were used to test HMGB-1 expression in lung tissue and serum. RAGE and NF-κB changes were determined by Real-time PCR and Western blot. Compared with control, ALI group presented decreased PaO2 and PH, elevated W/D, enhanced MPO activity, declined SOD activity, upregulated HMGB-1 mRNA, increased HMGB-1 secretion, and increased RAGE and NF-κB mRNA and protein (p < 0.05). Ketamine treatment significantly elevated PaO2 and PH, reduced W/D, declined MPO activity, enhanced SOD activity, inhibited HMGB-1 mRNA and secretion, and downregulated RAGE and NF-κB mRNA and protein (p < 0.05). Ketamine can alleviate LPS induced lung injury through inhibiting HMGB1-RAGE level. It could be treated as a new choice for ALI treatment.

From Human Megakaryocytes to Platelets: Effects of Aspirin on High-Mobility Group Box 1/Receptor for Advanced Glycation End Products Axis.

Platelets (PLTs) are the major source of high-mobility group box 1 (HMGB1), a protein that is involved in sterile inflammation of blood vessels and thrombosis. Megakaryocytes (MKs) synthesize HMGB1 and transfer both protein and mRNA into PLTs and PLT-derived microvesicles (MV). Free HMGB1 found in supernatants of in vitro differentiated MKs and in a megakaryoblastic cell line (DAMI cells). Aspirin “in vivo” and “in vitro” not only reduces HMGB1 and receptor for advanced glycation end products expression on MKs and PLTs but also drives the movement of HMGB1 from MKs into PLTs and PLT-derived MV. These findings suggest that consumption of low doses of aspirin reduces the risk of atherosclerosis complications as well as reducing PLT aggregation by the inhibition of COX-1.

Expression of high-mobility group box-Ⅰ and N-methyl-D-aspartate receptor in status epilepticus

Objective: To investigate the expression changes of high mobility group box-1 (HMGB1) and the 2B receptor of N- methyl -D- aspartate receptor (NR2B) in status epilepticus (SE). Methods: (1) Primary hippocampal neurons from SD rats with 16 to 18 days of fetal age were cultured in vitro for 7 days, and exposed to Mg(2+) free media for 3 hours. Those cultured neurons were randomly divided into control group and intermittent hypoxia group. (2) SD rats with similar weight were selected and randomly divided into control group and SE model group. The rat model with SE was established by an intraperitoneal injection of lithium chloride-piloearpine (LI-PILO). Real-time PCR technique was used to detect the expression of HMGB1 and NR2B mRNA. Results: In Sombati's cell model cultured in normal concentration of oxygen, the HMGB1 mRNA expression levels were 0.005 01±0.000 54, 0.026 76±0.003 75, 0.003 52±0.000 33, and the NR2B mRNA expression levels were 0.008 84±0.000 69, 0.012 23±0.000 90, 0.029 11±0.000 71, respectively, at 2, 4 and 6 h; compared with the expressions of HMGB1 and NR2B mRNA at the same time points of Sombatis cell model groups, the differences were also significant (all P<0.05). After the successful establishment of epilepsy model, the HMGB1 mRNA expression levels were 0.000 11±0.000 09, 0.000 18±0.000 01, 0.000 11±0.000 01, and the NR2B mRNA expression levels were 0.196 12±0.009 41, 0.232 11±0.006 27, 0.272 48±0.005 84, respectively, at 6, 8 and 10 h; compared with the expressions of HMGB1 and NR2B mRNA at the same time points of control groups, the differences were all significant (all P<0.05). Conclusion: HMGB1 mRNA expression levels increase at 2, 4 h, decrease at 6 h in the Sombati's cell model in normal oxygen culture, while increase at 6, 8 h, and decrease at 10 h in LI-PILO induced rat model with SE; the NR2B mRNA relative expression increases with time in both the Sombati's cell model in normal oxygen culture and rat model of SE.

Systemic lidocaine inhibits high-mobility group box 1 messenger ribonucleic acid expression and protein in BALB/c mice after closed fracture musculoskeletal injury.

Background:Severe musculoskeletal trauma can trigger an inflammatory response, and an excessive inflammatory response can lead to systemic inflammatory response syndrome and multiorgan failure. High-mobility group box 1 (HMGB1) is an early mediator pro-inflammatory cytokine in sterile injuries and a late cytokine mediator in infection and sepsis. Previous research has shown that administration of systemic lidocaine can inhibit HMGB1 expression in macrophages of septic rats. The aim of this study was to demonstrate the efficacy of systemic lidocaine to inhibit HMGB1 mRNA and protein in a BALB/c mouse model of sterile inflammation due to closed fracture musculoskeletal injury.Materials and Methods:Twenty adult male BALB/c mice were divided into lidocaine and control groups. The closed fracture musculoskeletal injury was performed by breaking the left thigh bone of the mice. Four hours after undergoing the closed fracture, the lidocaine group was treated with lidocaine intravenous (2 mg/kg). The same volume of distilled water was injected into the control group instead of lidocaine. HMGB1 mRNA expression was examined with real-time polymerase chain reaction, and HMGB1 protein level was determined with enzyme-linked immunosorbent assay.Results:The expression of HMGB1 mRNA and protein levels in mice that sustained inflammation due to a closed fracture musculoskeletal injury was significantly decreased in the lidocaine group (P < 0.00 and P < 0.00 for mRNA and protein, respectively).Conclusions:Intravenous administration of lidocaine effectively inhibited the inflammatory process in BALB/c mice that underwent closed fracture musculoskeletal injury by suppressing HMGB1 mRNA transcription and HMGB1 protein translation.

Interferon Regulatory Factor 1 Activates Autophagy to Aggravate Hepatic Ischemia-Reperfusion Injury by Increasing High Mobility Group Box 1 Release

Background/Aims: Interferon regulatory factor 1(IRF-1) and high mobility group box 1(HMGB1) have been independently identified as being key players in hepatic ischemia-reperfusion injury (IRI). We attempted to determine whether IRF-1 activates autophagy to aggravate hepatic IRI by increasing HMGB1 release. Methods: The hepatic IRI model was generated in C57BL/6 mice, euthanized at 2, 6, 12 or 24 h after reperfusion. To examine the effects of HMGB1 release inhibition, Glycyrrhiza acid (GA) was administered to the mice and at six hours after injectiont. AML12 cells were immersed in mineral oil for 90 min and then cultured in complete Dulbecco’s Modified Eagle’s Medium (DMEM)/F12 to simulate IRI. AML12 cells were treated with IRF-1 siRNA, Ad-IRF-1 or GA. The serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), as well as histological changes were examined. Next, autophagic vacuoles were detected by transmission electron microscopy (TEM) or LC3 dots. The expression of IRF-1 and HMGB1 mRNA were measured by real-time polymerase chain reaction. The expression of IRF-1, microtubule-associated protein 1 light chain 3 (LC3), Bcl-2, Beclin 1, HMGB1 were detected by western blotting or immunohistochemistry. Results: The levels of hepatic IRF-1, mRNA and protein were significantly increased in livers after exposure to IRI, together with, IRI-induced increase of HMGB1 mRNA and release of HMGB1 in liver tissue. Knockout of IRF-1 decreased expression and release of HMGB1 in liver, and inhibiting the release of HMGB1 could alleviate hepatic IRI. In addition, knockout of IRF-1 downregulated LC3II and Beclin1, while number of autophagosomes or LC3 dots were increased. Up-regulating IRF-1 expression could increase the levels of LC3Ⅱ expression in AML12 cells after exposure to IRI. The levels of HMGB1 in Ad-IRF-1 transfected AML12 cell supernatants increased, together with number of LC3 dots increasing. However, GA could inhibit both Ad-IRF-1 induced HMGB1 release and the increase in the number of LC3 dots. Conclusions: IRF-1 activates autophagy to aggravate hepatic IRI by increasing HMGB1 release.

Macrophage migration inhibitory factor mediates protease-activated receptor 4-induced bladder pain through urothelial high mobility group box 1.

Macrophage migration inhibitory factor (MIF) mediates pain although the mechanisms are not well understood. Urothelial activation of protease activated receptor 4 (PAR4) results in urothelial MIF release, urothelial high mobility group box 1 (HMGB1) release and bladder pain in mice without bladder inflammation. All three effects are prevented by MIF inhibition while intravesical disulfide HMGB1 alone can induce bladder pain. This study utilizes genetic MIF deletion to determine whether MIF mediates PAR4‐induced bladder pain and is upstream of HMGB1‐induced bladder pain. Wild type (C57/BL6) and MIF knockout (KO) mice were treated with intravesical PAR4 activating peptide or disulfide HMGB1 and tested for abdominal mechanical hypersensitivity at baseline (before treatment) and 24 h after injection. Micturition parameters and bladder histology were examined after behavioral test. Real‐time PCR and western blotting measured HMGB1 mRNA and protein levels in the bladders of naïve wild type and MIF KO mice, while immunofluorescence measured HMGB1 protein levels in the urothelium of both strains. Intravesical PAR4 activation resulted in abdominal mechanical hypersensitivity in wild‐type mice but not MIF KO mice. Intravesical disulfide HMGB1 induced abdominal mechanical hypersensitivity in both strains. Neither treatment resulted in significant changes in micturition or bladder histology in either strain. HMGB1 mRNA and protein levels were higher in MIF KO mouse bladders and the urothelium of MIF KO bladder had greater immunostaining than the wild‐type strain. MIF is a pivotal molecule mediating PAR4‐induced bladder pain and regulating urothelial HMGB1 production and release to elicit bladder pain.

High mobility group box-1 (HMGB1) is increased in injured mouse spinal cord and can elicit neurotoxic inflammation

Inflammation is a ubiquitous but poorly understood consequence of spinal cord injury (SCI). The mechanisms controlling this response are unclear but culminate in the sequential activation of resident and recruited immune cells. Collectively, these cells can exert divergent effects on cell survival and tissue repair. HMGB1 is a ubiquitously expressed DNA binding protein and also a potent inflammatory stimulus. Necrotic cells release HGMB1, but HMGB1 also is actively secreted by inflammatory macrophages. A goal of this study was to quantify spatio-temporal patterns of cellular HMGB1 expression in a controlled mouse model of experimental SCI then determine the effects of HMGB1 on post-SCI neuroinflammation and recovery of function. We documented SCI-induced changes in nuclear and cytoplasmic distribution of HMGB1 in various cell types after SCI. The data reveal a time-dependent increase in HMGB1 mRNA and protein with protein reaching maximal levels 24–72 h post-injury then declining toward baseline 14–28 days post-SCI. Although most cells expressed nuclear HMGB1, reduced nuclear labeling with increased cytoplasmic expression was found in a subset of CNS macrophages suggesting that those cells begin to secrete HMGB1 at the injury site. In vitro data indicate that extracelluar HMGB1 helps promote the development of macrophages with a neurotoxic phenotype. The ability of HMGB1 to elicit neurotoxic macrophage functions was confirmed in vivo; 72 h after injecting 500 ng of recombinant HMGB1 into intact spinal cord ventral horn, inflammatory CNS macrophages co-localized with focal areas of neuronal killing. However, attempts to confer neuroprotection after SCI by blocking HMGB1 with a neutralizing antibody were unsuccessful. Collectively, these data implicate HMGB1 as a novel regulator of post-SCI inflammation and suggest that inhibition of HMGB1 could be a novel therapeutic target after SCI. Future studies will need to identify better methods to deliver optimal concentrations of HMGB1 antagonists to the injured spinal cord.

The HMGB1/RAGE Pro-Inflammatory Axis in the Human Placenta: Modulating Effect of Low Molecular Weight Heparin.

We evaluated whether physiological and pre-eclamptic (PE) placentae, characterized by exacerbated inflammation, presented alterations in pro-inflammatory High Mobility Group Box 1 (HMGB1) and its Receptor of Advanced Glycation End products (RAGE) expression. Moreover, we investigated, in physiological placental tissue, the ability of Low Molecular Weight Heparin (LMWH) to modify HMGB1 structural conformation thus inhibiting RAGE binding and HMGB1/RAGE axis inflammatory activity. HMGB1, RAGE, IL-6 and TNFα (HMGB1/RAGE targets) mRNA expression were assessed by Real Time PCR. HMGB1, RAGE protein levels were assessed by western blot assay. Physiological term placental explants were treated by 0.5 U LMWH for 24 or 48 h. HMGB1 and RAGE expression and association were evaluated in LMWH explants by RAGE immunoprecipitation followed by HMGB1 immunoblot. HMGB1 spatial localization was evaluated by immuofluorescent staining (IF). HMGB1 expression was increased in PE relative to physiological placentae while RAGE was unvaried. 24 h LMWH treatment significantly up-regulated HMGB1 expression but inhibited HMGB1/RAGE complex formation in physiological explants. RAGE expression decreased in treated relative to untreated explants at 48 h. IF showed HMGB1 localization in both cytoplasm and nucleus of mesenchymal and endothelial cells but not in the trophoblast. IL-6 and TNFα gene expression were significantly increased at 24 h relative to controls, while they were significantly down-regulated in 48 h vs. 24 h LMWH explants. Our data depicted a new molecular mechanism through which LMWH exerts its anti-inflammatory effect on PE placentae, underlying the importance of HMGB1/RAGE axis in PE inflammatory response.

MicroRNA-142-3p relieves neuropathic pain by targeting high mobility group box 1.

MicroRNA (miRNA) are emerging as critical regulators of neuropathic pain development. Neuroinflammation contributes to the development of neuropathic pain. miR‑142‑3p has been characterized as an inflammation‑related miRNA in various pathological processes. However, little is known about the role of miR‑142‑3p in neuroinflammation and neuropathic pain. The present study aimed to investigate the function of miR‑142‑3p in neuropathic pain by creating a murine model using spinal nerve ligation(SNL). A significant reduction in miR‑142‑3p expression was observed in the dorsal root ganglion of mice with SNL (P<0.05) compared with control mice. Overexpression of miR‑142‑3p significantly inhibited neuropathic pain and neuroinflammation in mice with SNL (P<0.05). High mobility group box1 (HMGB1) was identified as a direct target gene of miR‑142‑3p by bioinformatic analysis and dual‑luciferase reporter assays. Overexpression of miR‑142‑3p significantly reduced the mRNA and protein expression levels of HMGB1 invitro and invivo (P<0.05). In addition, HMGB1 mRNA expression and miR‑142‑3p expression were inversely correlated in mice with SNL. Furthermore, overexpression of HMGB1 significantly reversed the inhibitory effect of miR‑142‑3p on neuroinflammation and neuropathic pain development (P<0.05). Overall, these results suggest that miR‑142‑3p functions as a negative regulator of neuropathic pain development through the downregulation of HMGB1, indicating that miR‑142‑3p may serve as a potential therapeutic target for neuropathic pain.

Glycyrrhizin suppresses the expressions of HMGB1 and ameliorates inflammative effect after acute subarachnoid hemorrhage in rat model

High-mobility group box 1 (HMGB1), a nuclear protein that has endogenous cytokine-like activity, is involved in early brain injury after subarachnoid hemorrhage (SAH) by mediating inflammatory response. This study was conducted to investigate the effect of glycyrrhizin as an inhibitor of HMGB1 in a rat SAH model. Experimental SAH was induced by using autologous blood injection to prechiasmatic cistern. 15 mg/kg glycyrrhizin was administered immediately after SAH induction, and then administered once at 6, 12 and 18 h. All the rats were sacrificed at 24 h after neurological assessment and frontal brain tissue was taken for assay. Blood–brain barrier (BBB) permeability was determined by Evans blue (EB) extravasation. The expression of HMGB1 were detected by immunofluorescence, western blot and quantitative real-time PCR. Inflammatory mediators (TNF-α, IL-1β) were measured using specific ELISA. Fluoro-Jade C staining and TUNEL staining was performed for the quantitative assessment of neuronal injury. We found the use of glycyrrhizin significantly improved neurological scores, reduced HMGB1-positive cells, down-regulated mRNA and protein levels of HMGB1, inhibited BBB permeability, and attenuated neuronal cell death and apoptosis after SAH. The up-regulations of inflammation-related molecules (TNF-α, IL-1β) in SAH rats were suppressed by glycyrrhizin treatment. These findings suggest that glycyrrhizin is a potential candidate for the treatment of inflammatory brain injury after SAH.

High Mobility Group Box 1 Protein Level as a Novel Biomarker for the Development of Peri-Implant Disease

Peri-implant disease is a chronic inflammation of the soft and hard tissues around a dental implant, resulting from bacterial infection. Recent evidence indicates that some pro-inflammatory cytokines and chemokines released by immunocytes are substantially responsible for the progress and consequence of inflammation. High mobility group box 1 (HMGB1) is released into the extracellular matrix and acts as a key pro-inflammatory factor during injury, necrosis and inflammation. A higher concentration of HMGB1 has been found in gingival crevicular fluid from inflammatory gingival tissue than from healthy sites. HMGB1 mRNA and protein are overexpressed in murine periodontal ligament fibroblasts stimulated with lipopolysaccharide (LPS) and IL-1β. Thus, this study sought to assess HMGB1 expression in peri-implant crevicular fluid (PICF) at each stage of peri-implant disease and to investigate the correlation between HMGB1 and peri-implant disease progress. The results demonstrated that the HMGB1 expression level in PICF is indicative of the progress of peri-implant disease and hence may be a useful diagnostic and prognostic biomarker for peri-implant tissue.

Potential mechanisms of microRNA-141-3p to alleviate chronic inflammatory pain by downregulation of downstream target gene HMGB1: in vitro and in vivo studies

The present study aimed to investigate the potential role of microRNA-141-3p (miR-141-3p) in chronic inflammatory pain (CIP) by targeting the high-mobility group box1 (HMGB1) gene. In the in vitro study, BV2 microglial cells were selected and assigned into blank, lipopolysaccharide (LPS), miR-141-3p mimics, mimics control, miR-141-3p inhibitor, inhibitor control, miR-141-3p mimics+LPS, mimics control+ LPS, miR-141-3p inhibitor+LPS and inhibitor control+LPS groups. Ninety-six rats were randomly divided into 8 groups (12 rats in each group): blank control, model control, negative control (NC), miR-141-3p mimics+ complete Freund's adjuvant (CFA), mimics control+CFA, HMGB1 short hairpin RNA (shRNA)+CFA, HMGB1 NC+CFA and miR-141-3p mimics+HMGB1 shRNA+CFA groups. The quantitative real-time PCR, western blotting, enzyme-linked immunosorbent assay and pain behavioral test were used to measure the miR-141-3p and HMGB1 mRNA expressions, HMGB1 protein expression, inflammatory cytokines levels, and thermal and mechanical pain thresholds, respectively. Compared with the blank, mimics control, inhibitor control and miR-141-3p mimics+LPS groups, the miR-141-3p mimics group had increased miR-141-3p expression and interleukin (IL)-10 levels, and had decreased mRNA and protein expressions of HMGB1 and the levels of IL-1β, tumor necrosis factor-α (TNF-α) and IL-6, whereas the opposite trend were found in the LPS, miR-141-3p inhibitor, mimics control+LPS and inhibitor control+LPS groups. Compared with the LPS, miR-141-3p inhibitor, mimics control+LPS and inhibitor control+LPS groups, the miR141-3p+LPS group had an obviously decreased expression of miR-141-3p and IL-10, increased mRNA and protein expressions of HMGB1 and the levels of IL-1β, TNF-α and IL-6. Compared with the rats in the blank control group, the miR-141-3p expression, IL-10 level, and thermal and mechanical pain thresholds decreased significantly, whereas the mRNA and protein expressions of HMGB1, IL-1β, TNF-α and IL-6 increased significantly in rats in the NC, mimics control+CFA and HMGB1 NC+ CFA groups. The miR-141-3p expression was increased in rats in the miR-141-3p mimics+HMGB1 shRNA+CFA group. Our study demonstrated that miR-141-3p can alleviate the CIP by downregulating the downstream target gene HMGB1.

Relationships of BRAF mutation and HMGB1 to papillary thyroid carcinoma

A poor papillary thyroid cancer (PTC) prognosis is strongly associated with the BRAF V600E mutation. During tumor progression, levels of the high mobility group box 1 (HMGB1) protein are often dysregulated. Results herein demonstrate that HMGB1 protein levels differ between tumor and adjacent non-tumor tissue and that HMGB1 mRNA levels were higher in wild-type BRAF PTC tissues than in BRAF V600E PTC tissues (2-△Ct 0.31 ± 0.25 vs. 0.16 ± 0.12; P < 0.05). HMGB1 protein levels also differed in the same manner (wild-type BRAF PTC tissues 0.11 ± 0.04 vs. BRAF V600E PTC tissues 0.03 ± 0.03; P < 0.001). Although not detected in peripheral blood, low levels of HMGB1 were significantly related to PTC cell lymph node metastasis and extra-glandular infiltration (P = 0.045 and P = 0.002). Experimental results at the cellular level were consistent with tissues and further verified the relationship of BRAF V600E and HMGB1. These findings demonstrate that the BRAF V600E mutation down-regulates levels of HMGB1, likely through activation of the mitogen-activated protein kinase (MAPK) signaling pathways.

HMGB1 attenuates TGF-β-induced epithelial-mesenchymal transition of FaDu hypopharyngeal carcinoma cells through regulation of RAGE expression.

Abnormal expression of high-mobility group box-1 (HMGB1) protein occurs in many tumors and is closely associated with tumor invasion and metastasis. However, a role for HMGB1 in epithelial-mesenchymal transition (EMT) in hypopharyngeal carcinoma has not been previously reported. We cultured cells of the hypopharyngeal carcinoma cell line FaDu in vitro and then treated them with 5ng/ml TGF-β1 for 48h to induce EMT. Vimentin, Snail, and HMGB1 expression patterns were then detected using immunofluorescence staining; HMGB1 mRNA and protein expression were verified by RT-PCR and western blot analyses. HMGB1 was then silenced in FaDu cells using RNAi, followed by detection of Vimentin, Snail, and HMGB1 expressions by immunofluorescence staining. The mRNA expression levels of Vimentin, Snail, HMGB1, and E-cadherin were verified by RT-PCR, while protein expression of HMGB1 and receptor for advanced glycation end products (RAGE) were detected by western blot analysis. The biological behavior of FaDu cells was observed before and after HMGB1 silencing using wound healing and cell invasion assays. Following culture with 5ng/ml TGF-β1 for 48h, the morphology of FaDu cells changed from a regular cobblestone-like appearance into a spindle-like shape. Expression levels of Vimentin, Snail, and HMGB1 were upregulated at both mRNA and protein levels as determined by RT-PCR, immunofluorescence, and western blotting. After HMGB1 silencing, mRNA expression levels of the epithelial cell marker E-cadherin were upregulated. Meanwhile, expression levels of the mesenchymal markers Vimentin and Snail were decreased. Western blotting revealed that HMGB1 and RAGE were downregulated. RNAi-mediated inhibition of HMGB1 expression decreased the capacities of FaDu cells for invasion and metastasis as determined by wound healing and cell invasion assays. HMGB1 is essential for maintaining the interstitial cell phenotype in TGF-β1-induced EMT of FaDu cells, and silencing HMGB1 greatly inhibits the invasive and metastatic ability of these cells.