Hmo1:A versatile member of the high mobility group box family of chromosomal architecture proteins

Eukaryotic chromatin consisting of nucleosomes connected by linker DNA is organized into higher order structures,which is facilitated by linker histone H1.Formation of chromatin compacts and protects the genome,but also hinders DNA transactions.Cells have evolved mechanisms to modify/remodel chromatin resulting in chromatin states suitable for genome functions.The high mobility group box(HMGB)proteins are non-histone chromatin architectural factors characterized by one or more HMGB motifs that bind DNA in a sequence nonspecific fashion.They play a major role in chromatin dynamics.The Saccharomyces cerevisiae(yeast hereafter)HMGB protein Hmo1 contains two HMGB motifs.However,unlike a canonical HMGB protein that has an acidic C-terminus,Hmo1 ends with a lysine rich,basic,C-terminus,resembling linker histone H1.Hmo1 exhibits characteristics of both HMGB proteins and linker histones in its multiple functions.For instance,Hmo1 promotes transcription by RNA polymerases I and II like canonical HMGB proteins but makes chromatin more compact/stable like linker histones.Recent studies have demonstrated that Hmo1 destabilizes/disrupts nucleosome similarly as other HMGB proteins in vitro and acts to maintain a common topological architecture of genes in yeast genome.This minireview reviews the functions of Hmo1 and the underlying mechanisms,highlighting recent discoveries.

Suppressing high mobility group box-1 release alleviates morphine tolerance via the adenosine5'-monophosphate-activated protein kinase/heme oxygenase-1 pathway

Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.

The Expression and Functional Analysis of the Gene At2G34450 in High Mobility Group B Proteins from Arabidopsis thaliana

[Objective]To better understand the functions of High Mobility Group B （HMGB） proteins in the transcriptional regulation of plant stress responses.[Method]We cloned the At2G33450 gene encoding At2G34450 protein in Arabidopsis thaliana.Binary vectors carrying the above gene were transformed into Arabidopsis to detect the influences of environmental stimuli to transgenic Arabidopsis.[Result] Under salt or drought stress the transgenic Arabidopsis plants over-expressed At2G33450 displayed retarded germination and subsequent growth compared with wild-type plants.[Conclusion]Our results provide a novel basis for understanding the biological functions of HMGB protein family members that differently affect germination and seedling growth of Arabidopsis plants under various stress conditions.

Effect on proliferation and apoptosis of retinoblastoma cell by RNA inhibiting high mobility group protein box-1 expression

AIM： To investigate the effect of high mobility group protein box-1 （HMGB1） siRNA on proliferation and apoptosis of retinoblastoma （Rb） cells.METHODS： The expression of HMGB1 in Rb cells were detected by real-time polymerase chain reaction （RT-PCR） and Western blot. Chemically synthesized HMGB1 siRNA was transfected into Y79 cells. The inhibitory rate was also examined by RT-PCR and Western blot. After HMGB1 siRNA transfection, the cell proliferation was analyzed by MTT, and cell apoptosis was detected by Caspase-3 active detection kit. Cell cycle distribution and apoptosis were detected by flow cytometry. RESULTS： The expression of HMGB1 significantly elevated in Rb cells （P〈0.01）. After transfected by siRNA, the HMGB1 protein level of Y79 cells was significantly reduced （P〈0.01）. After siRNA interference HMGB1, the proportion of proliferating cells reduced, and the proportion of quiescent cells increased （P〈0.05）. In addition, apoptosis rate of Y79 cells increased from 2.03% to 9.10% after interfering with HMGB1 siRNA （P〈0.05）.CONCLUSION： Specific HMGB1 siRNA can inhibit the expression of HMGB1. The effect may be attributed to inhibit the proliferation and promote cell apoptosis.

Expression and Purification of Arabidopsis High Mobility Group B Protein Gene At2G34450 in Pichia pastoris

[Objective] The aim was to study the expression of Arabidopsis gene A/2G34450 in Pichia pastoris and to obtain recombinant Arabidopsis HMGB protein. [Method] The At2G34450 gene was cloned into yeast expression vector pPIC9K containing AOXl promoter and the sequences of secreting α-signal peptides. Recombinant plasmid was linearized by Sal l and transformed into P. pastoris GSl15 competent cells by electroporation. Positive integrated clones were screened out, and the At2G34450 protein was expressed under the induction of methanol. [Result] The At2G34450 protein was expressed in yeast medium through methanol induction. SDS-PAGE results showed that recombination product was At2G34450 protein. [Conclusion] At2G34450 protein was successfully expressed in the P. pastoris system for the first time, which paves a direct path to further research on the functions of HMGB family members.

Relationship of plasma homocysteine, soluble intercellular adhesion molecule-1, high mobility group box 1 protein with carotid intima-media thickness in elderly patients with type 2 diabetes mellitus

Objective:To explore the relationship of plasma homocysteine(Hcy),soluble intercellular adhesion molecule-1(sICAM-1)and high mobility group box 1 protein(HMGB1)with carotid intima-media thickness(c-IMT)in elderly patients with type 2 diabetes mellitus.Methods:A total of 100 elderly patients who were diagnosed as type 2 diabetes mellitus in Baogang Hospital of Inner Mongolia from June 2017 to May 2020 were chosen as research objects.According to c-IMT,they were divided into the normal group(n=35),the mild to moderate group(n=41)and the severe group(n=24).The expression levels of plasma Hcy,sICAM-1 and HMGB1 were compared between groups respectively.Pearson’s correlation coefficient was used to analyze the relationship of plasma Hcy,sICAM-1,HMGB1 with c-IMT.Results:The comparison in plasma Hcy,sICAM-1,HMGB1 and c-IMT among the three groups of patients was of statistical significance(p<.05).The results of correlation analysis showed that the expression levels of plasma Hcy,sICAM-1 and HMGB1 were positively correlated with c-IMT in elderly patients with type 2 diabetes mellitus(r=.627,.598,.614;p<.05).Conclusions:The expression levels of plasma Hcy,sICAM-1 and HMGB1 are abnormally increased in elderly patients with type 2 diabetes mellitus,and related to c-IMT,which can provide a strong evidence for clinical diagnosis and treatment by detecting their levels in clinical practice.

High-mobility group box 1 protein and its role in severe acute pancreatitis

The high mobility group box 1(HMGB1),which belongs to the subfamily of HMG-1/-2,is a highly conserved single peptide chain consisting of 215 amino acid residues with a molecular weight of approximately 24894 Da.HMGB1 is a ubiquitous nuclear protein in mammals and plays a vital role in inflammatory diseases.Acute pancreatitis is one of the most common causes of acute abdominal pain with a poor prognosis.Acute pancreatitis is an acute inflammatory process of the pancreas(duration of less than six months),for which the severe form is called severe acute pancreatitis(SAP).More and more studies have shown that HMGB1 has a bidirectional effect in the pathogenesis of SAP.Extracellular HMGB1 can aggravate the pancreatic inflammatory process,whereas intracellular HMGB1 has a protective effect against pancreatitis.The mechanism of HMGB1 is multiple,mainly through the nuclear factor-κB pathway.Receptors for advanced glycation endproducts and toll-like receptors(TLR),especially TLR-2 and TLR-4,are two major types of receptors mediating the inflammatory process triggered by HMGB1 and may be also the main mediators in the pathogenesis of SAP.HMGB1 inhibitors,such as ethyl pyruvate,pyrrolidine dithiocarbamate and Scolopendra subspinipes mutilans,can decrease the level of extracellular HMGB1 and are the promising targets in the treatment of SAP.

High mobility group box-1 protein inhibits regulatory T cell immune activity in liver failure in patients with chronic hepatitis B

BACKGROUND: Liver failure in chronic hepatitis B (CHB) patients is a severe, life-threatening condition. Intestinal endotoxemia plays a significant role in the progress to liver failure. High mobility group box-1 (HMGB1) protein is involved in the process of endotoxemia. Regulatory T (Treg) cells maintain immune tolerance and contribute to the immunological hyporesponsiveness against HBV infection. However, the roles of HMGB1 and Treg cells in the pathogenesis of liver failure in CHB patients, and whether HMGB1 affects the immune activity of Treg cells are poorly known at present, and so were explored in this study. METHODS: The levels of HMGB1 expression were detected by ELISA, real-time RT-PCR, and Western blotting, and the percentage of CD4(+)CD25(+)CD127(low) Treg cells among CD4(+) cells was detected by flow cytometry in liver failure patients with chronic HBV infection, CHB patients, and healthy controls. Then, CD4(+)CD25(+)CD127(low) Treg cells isolated from the peripheral blood mononuclear cells from CHB patients were stimulated with HMGB1 at different concentrations or at various intervals. The effect of HMGB1 on the immune activity of Treg cells was assessed by a suppression assay of the allogeneic mixed lymphocyte response. The levels of forkhead box P3 (Foxp3) expression in Treg cells treated with HMGB1 were detected by RT-PCR and Western blotting. RESULTS: A higher level of HMGB1 expression and a lower percentage of Treg cells within the population of CIA(+) cells were found in liver failure patients than in CHB patients (82.6+/-20.1 mu g/L vs. 34.2+/-13.7 mu g/L; 4.55+/-1.34% vs. 9.52+/-3.89%, respectively). The immune activity of Treg cells was significantly weakened and the levels of Foxp3 expression were reduced in a dose- or time-dependent manner when Treg cells were stimulated with HMGB1 in vitro. CONCLUSIONS: The high level of HMGB1 and the low percentage of Treg cells play an important role in the pathogenesis of liver failure in patients with chronic HBV infection. Moreover, HMGB1 can weaken the immune activity of Treg cells. It is suggested that effectively inhibiting HMGB1 expression could be a feasible way to treat liver failure by suppressing endotoxemia and enhancing Treg cell activity.

Novel insights for high mobility group box 1 proteinmediated cellular immune response in sepsis:A systemic review

High mobility group box 1 protein （HMGB1） is a highly conserved, ubiquitous protein in the nuclei and cytoplasm of nearly all cell types. HMGB1 is secreted into the extracellular milieu and acts as a proinflammatory cytokine. In this article we reviewed briefly the cellular immune response mediated by HMGB1 in inflammation and sepsis. This systemic review is mainly based on our own work and other related reports HMGB1 can actively affect the immune functions of many types of cells including T lymphocytes, regulatory T cells （Tregs）, dendritic cells （DCs）, macrophages, and natural killer cells （NK cells）. Various cellular responses can be mediated by HMGB1 which binds to cell-surface receptors [e.g., the receptor for advanced glycation end products （RAGE）, Toll-like receptor （TLR）2, and TLR4]. Anti-HMGB1 treatment, such as anti-HMGB1 polyclonal or monoclonal antibodies, inhibitors （e.g., ethyl pyruvate） and antagonists （e.g., A box）, can protect against sepsis lethality and give a wider window for the treatment opportunity. HMGB1 is an attractive target for the development of new therapeutic strategies in the treatment of patients with septic complications.

Expression of high mobility group protein B1 in the lungs of rats with sepsis

BACKGROUND： Vibrio vulnifi cus inside the body could activate the NF-!B signaling pathwayand initiate the inflammatory cascade. The lung is one of the earliest organs affected by sepsisassociated with acute lung injury. High mobility group protein B1 （HMGB1） is an important late-actingpro-infl ammatory cytokine involving in the pathophysiology of sepsis. It is also involved in the injuryprocess in the lung, liver and intestine. There has been no report on the involvement of HMGB1 inVibrio vulnifi cus sepsis-induced lung injury.METHODS： Sixty rats were randomly divided into a normal control group （group A, n=10） anda Vibrio vulnificus sepsis group （group B, n=50）. Sepsis was induced in the rats by subcutaneousinjection of Vibrio vulnificus （concentration 6×108 cfu/mL, volume 0.1 mL/100g）） into the left lowerlimbs. The rats in group B were sacrifi ced separately 1, 6, 12, 24, and 48 hours after the infection.Their lungs were stored as specimens, lung water content was measured, and lung pathology wasobserved under a light microscope. The expressions of the HMGB1 gene and protein in the lungswere detected by RT-PCR and Western blot. Data were analyzed with one-way analysis of variance（ANOVA） and the LSD method for pair-wise comparison between the two groups. P〈0.05 wasconsidered statistically signifi cant.RESULTS： Compared to group A （0.652±0.177）, HMGB1 mRNA expression in the lungs ofgroup B was signifi cantly higher at 0 hour （1.161±0.358, P=0.013）, 24 hours （1.679±0.235, P=0.000）,and 48 hours （1.258±0.274, P=0.004） （P〈0.05）, and peaked at 24 hours. Compared to group A（0.594±0.190）, HMGB1 protein expression at 6 hours （1.408±0.567, P=0.026） after infection wassignificantly increased （P〈0. 05）, and peaked at 24 hours （2.415±1.064, P=0.000） after infection.Compared to group A （0.699±0.054）, lung water content was significantly increased at 6 hours（0.759±0.030, P=0.001）,12 hours （0.767±0.023, P=0.000）, 24 hours （0.771±0.043, P=0.000） and 48hours （0.789±0.137, P=0.000） after infection （P〈0.05）. Compared to group A, pathological changesat 12 hours in group B indicate marked pulmonary vascular congestion, interstitial edema andinfl ammatory infi ltration. Alveolar cavity collapse and boundaries of the alveolar septum could not beclearly identifi ed.CONCLUSION： Vibrio vulnifi cus sepsis can lead to injury in rat lungs, and increased HMGB1expression in lung tissue may be one of the mechanisms for injury from Vibrio vulnifi cus sepsis.

High mobility group protein 1: A collaborator in nucleosome dynamics and estrogen-responsive gene expression

High mobility group protein 1(HMGB1) is a multifunctional protein that interacts with DNA and chromatin to influence the regulation of transcription, DNA replication and repair and recombination. We show that HMGB1 alters the structure and stability of the canonical nucleosome(N) in a nonenzymatic,adenosine triphosphate-independent manner. As a result, the canonical nucleosome is converted to two stable, physically distinct nucleosome conformers. Although estrogen receptor(ER) does not bind to its consensus estrogen response element within a nucleosome, HMGB1 restructures the nucleosome to facilitate strong ER binding. The isolated HMGB1-restructured nucleosomes(N' and N'') remain stable and exhibit a number of characteristics that are distinctly different from the canonical nucleosome. These findings complement previous studies that showed(1) HMGB1 stimulates in vivo transcriptional activation at estrogen response elements and(2) knock down of HMGB1 expression by siR NA precipitously reduced transcriptional activation. The findings indicate that a major facet of the mechanism of HMGB1 action involves a restructuring of aspects of the nucleosome that appear to relax structural constraints within the nucleosome. The findings are extended to reveal the differences between ER and the other steroid hormone receptors. A working proposal outlines mechanisms that highlight the multiple facets that HMGB1 may utilize in restructuring the nucleosome.

Inflammatory response and immune regulation of high mobility group box-1 protein in treatment of sepsis

Sepsis is an infection induced systemic inflammatory response syndrome and is a major cause of morbidity as well as mortality in intensive care units. A growing body of evidence suggests that the activation of a proinflammatory cascade is responsible for the development of immune dysfunction, susceptibility to severe sepsis and septic shock. The present theories of sepsis as a dysregulated inflammatory response and immune function, as manifested by excessive release of inflammatory mediators such as high mobility group box 1 protein （HMGB1）, are supported by increasing studies employing animal models and clinical observations of sepsis. HMGB1, originally described as a DNA-binding protein and released passively by necrotic cells and actively by macrophages/monocytes, has been discovered to be one of essential cytokines that mediates the response to infection, injury and inflammation. A growing number of studies still focus on the inflammation-regulatory function and its contribution to infectious and inflammatory disorders, recent data suggest that HMGB1 formation can also markedly influence the host cell-mediated immunity, including T lymphocytes and macrophages. Here we review emerging evidence that support extracellular HMGB1 as a late mediator of septic complications, and discuss the therapeutic potential of several HMGBl-targeting agents in experimental sepsis. In addition, with the development of traditional Chinese medicine in recent years, it has been proven that traditional Chinese herbal materials and their extracts have remarkable effective in treating severe sepsis. In this review, we therefore provide some new concepts of HMGBl-targeted Chinese herbal therapies in sepsis.

High mobility group box 1 protein(HMGB1)as an immune-modulating factor for polarization of human T lymphocytes

Objective This study was performed to investigate the effect of high mobility group box-1 protein(HMGB1)on immune function of human T lymphocytes in vitro and explore its potential role in cell-mediated immune dysfunction.Methods Fresh blood was obtained from healthy adult volunteers and peripheral blood mononuclear cells(PBMCs)were isolated,then rhHMGB1 was added to PBMCs.Four-color flow cytometric(FCM)analysis was used for the measurement of intracellular cytokine including interleukin IL-4 and interferon IFN-?ELISA kits were employed for the determination of IL-2 and sIL-2R protein levels in cell culture supernatants.Results(1)Different stimulating time and dosage of rhHMGB1 did not alter the number of IFN-αpositive cells(Th1).rhHMGB1 stimulation provoked a dose-dependent and time-dependent increase in Th2 subset and decrease in ratio of Th1 to Th2.(2)Compared with the untreated cells,when the cells were coincubated with rhHMGB1(10-100ng/ml)for 12 hrs,protein release of IL-2 and sIL-2R were significantly up-regulated.At 48 hrs,in contrast,protein production was relatively lower in cells after exposure to 100-1000 ng/ml rhHMGB1.Conclusions These findings demonstrated that HMGB1 has a dual influence on immune functions of human T lymphocytes.

Scolopendra subspinipes mutilans protected the ceruleininduced acute pancreatitis by inhibiting high-mobility group box protein-1

AIM:To evaluate the inhibitory effects of Scolopendra subspinipes mutilans(SSM) on cerulein-induced acute pancreatitis(AP) in a mouse model.METHODS:SSM water extract(0.1,0.5,or 1 g/kg) was administrated intraperitoneally 1 h prior to the first injection of cerulein.Once AP developed,the stable cholecystokinin analogue,cerulein was injected hourly,over a 6 h period.Blood samples were taken 6 h later to determine serum amylase,lipase,and cytokine levels.The pancreas and lungs were rapidly removed for morphological examination,myeloperoxidase assay,and real-time reverse transcription polymerase chain reaction.To specify the role of SSM in pancreatitis,the pancreatic acinar cells were isolated using collagenase method.Then the cells were pre-treated with SSM,then stimulated with cerulein.The cell viability,cytokine productions and high-mobility group box protein-1(HMGB-1) were measured.Furthermore,the regulating mechanisms of SSM action were evaluated.RESULTS:The administration of SSM significantly attenuated the severity of pancreatitis and pancreatitis associated lung injury,as was shown by the reduction in pancreatic edema,neutrophil infiltration,vacuolization and necrosis.SSM treatment also reduced pancreatic weight/body weight ratio,serum amylase,lipase and cytokine levels,and mRNA expression of multiple inflammatory mediators such as tumor necrosis factor-α and interleukin-1β.In addition,treatment with SSM inhibited HMGB-1 expression in the pancreas during AP.In accordance with in vivo data,SSM inhibited the cerulein-induced acinar cell death,cytokine,and HMGB-1 release.SSM also inhibited the activation of c-Jun NH2-terminal kinase,p38 and nuclear factor(NF)-κB.CONCLUSION:These results suggest that SSM plays a protective role during the development of AP and pancreatitis associated lung injury via deactivating c-Jun NH2-terminal kinase,p38 and NF-κB.

Effect of high mobility group box-1 protein on immune cells and its regulatory mechanism

High mobility group box-1 protein(HMGB1),which is a nuclear protein,participates in chromatin architecture and transcriptional regulation.When released from cells,HMGB1 also plays a well-established role as a pro-inflammatory mediator during innate immune responses to injury.In the initial stage of injury,there is a release of large quantities of early pro-inflammatory mediators to initiate or perpetuate immune responses against pathogens,but this pro-inflammatory period is transient,and it is followed by a prolonged period of immune suppression.At present,several lines of evidences have suggested that HMGB1 is a late cytokine provoking delayed endotoxin morbidity,which may enhance the production of early proinflammatory mediators,and it can contribute potently to the activation of different immune cells and play a role in the development of host cell-mediated immunity.The biology of HMGB1 has been extensively studied as a pro-inflammatory cytokine of systemic inflammation,however,this review will attempt to provide a summary of the effects of HMGB1 on different immune cells and its regulatory mechanism in acute insults.

Renal Expression and Clinical Significance of High Mobility Group Box 1 in Lupus Nephritis

Objective: To evaluate the clinical significance of high mobility group box 1 (HMGB1) expression in nephridial tissues of lupus nephritis (LN). Methods: Sixty-three patients with active LN and 15 systemic lupus erythematosus (SLE) (combined without LN) were included. Renal biopsies were performed in the two groups. The biopsies were evaluated according to the World Health Organization (WHO) classification and renal disease activity was estimated using the British Isles lupus assessment group (BILAG) index. Serum levels of HMGB1 were analyzed by western blot. HMGB1 expression in renal tissue was assessed by immunohistochemistry in the two groups. The correlation between HMGB1 and renal active index (AI), chronicity index (CI), pathological type of LN was analyzed. Results: LN biopsies showed WHO class III, IV or V and all patients had high renal disease activity (BILAG A/B). The HMGB1 expression was higher in the LN groups than the control groups (t = 9.263, P < 0.05). It showed positive correlation between HMGB1 expression and SLE DAI classification (r = 0.579, P P < 0.05) and renal tubule interstitial (TIL) classification (r = 0.815, P < 0.05), and negative correlation between HMGB1 expression and CI classification (r = 0.582, P < 0.05). In all patients, serum levels of HMGB1 increased only slightly in the patients only with SLE;however, in patients with LN WHO class IV a significant decrease was observed (P = 0.02). Immunostaining revealed a pronounced extranuclear HMGB1 expression predominantly outlining the glomerular endothelium and in the mesangium. There were significant differences in HMGB1 expression between LN and control biopsies and it existed with apparent association to histopathological classification and clinical outcome. Conclusions: Renal tissue expression and serum levels of HMGB1 were elevated in LN. The unusual elevation of HMGB1 in serum and tissue in LN may reflect persistent inflammatory activity, which clearly indicates a role for HMGB1 in pathogenesis of LN.

High mobility group box 1 protein： possible pathogenic link to atrial fibrillation

Atrial fibrillation （AF） is the most common sustained dysrhythmia in clinical practice. The bulk of evidence suggests that inflammatory processes, oxidative stress and matrix metalloproteinase are associated with development of AF. However, these agents may be involved in high mobility group box 1 protein （HMGB1）. We hypothesized that HMGB1 may be a possible pathogenic link to AF. A growing body of evidence supports these hypotheses. First, the level of serum HMGB1 is significantly increased in patients with AF including paroxysmal and persistent AF. Second, HMGB1 has been identified as a new pro-inflammatory cytokine in cardiovascular diseases, along with tumor necrosis factor （TNF）-a, interleukin （IL）-6, and C-reactive protein, and there is cross-talk between HMGB1 and inflammatory cytokines. Third, oxidative stress is involved in the release of the pro-inflammatory cytokine, HMGB1, indicating there is cross-talk between oxidative stress and inflammation, and oxidative stress may reinforce the effect of inflammation on the pathogenesis of AF and inflammation may play a more important role in the pathogenesis of AF. Fourth, HMGB1 can promote matrix metalloproteinase-9 upregulation and activation. Fifth, HMGB1 receptors （receptor for advanced glycation end products, Toll-like receptor-2,4） may mediate the atrial structural remodeling or be up-regulated in patients with non-valvular AF. These results suggest that HMGB1 may participate in the pathogenesis of AF and provide a potential target for pharmacoloclical interruption of AF.

下调HMGB2表达对肝癌LM3细胞上皮-间质转化的抑制作用及其AKT/mTOR信号通路机制

目的:探讨下调肝癌细胞中高迁移率族框蛋白2 (HMGB2)表达对肝癌细胞生物学行为及上皮-间质转化(EMT)进程的影响,并阐明其作用机制。方法:对数生长期的人肝癌LM3细胞分为阴性对照组和HMGB2 RNA干扰组(HMGB2 siRNA组),分别以Lipofectamin 2000为载体转染无关序列的RNA寡核苷酸(RNA oligo)和敲除HMGB2序列的RNA oligo。采用实时荧光定量PCR(RT-qPCR)法和Western blotting法检测2组细胞中HMGB2 mRNA和蛋白表达水平,分别采用细胞划痕实验和Transwell小室实验检测2组细胞的迁移和侵袭能力,采用Western blotting法检测2组细胞中E-钙黏蛋白(E-cadherin)、 N-钙黏蛋白(N-cadherin)、波形蛋白(Vimentin)和蛋白激酶B(AKT)/哺乳动物雷帕霉素靶蛋白(mTOR)通路相关蛋白表达水平。结果:与阴性对照组比较,HMGB2 siRNA组细胞中HMGB2 mRNA和蛋白表达水平均明显降低(P<0.05),HMGB2 siRNA组细胞划痕愈合率明显降低(P<0.01),侵袭细胞数明显减少(P<0.01),细胞中E-cadherin蛋白表达水平明显升高(P<0.01),N-cadherin、Vimentin、mTOR、AKT和磷酸化AKT (p-AKT)蛋白表达水平明显降低(P<0.05或P<0.01)。结论:下调HMGB2的表达可降低肝癌LM3细胞迁移和侵袭能力并抑制EMT,其作用机制可能与参与调节AKT/mTOR通路相关蛋白表达有关。

HMGB1中和抗体抑制细胞焦亡改善系统性红斑狼疮小鼠肺损伤的机制研究

目的探究高迁移率族蛋白1(high-mobility group box 1,HMGB1)中和抗体对系统性红斑狼疮(systemic lupus erythematosus,SLE)小鼠肺损伤的影响及机制。方法30只MRL/lpr小鼠随机分为MRL/lpr组、MRL/lpr+HMGB1中和抗体(anti-HMGB1)组、MRL/lpr+MCC950组,每组10只,另取10只野生型C57BL/6小鼠作为对照组,给药4周。苏木精-伊红(HE)染色和马松三色(Masson)染色观察各组小鼠肺组织病理学变化及胶原纤维沉积情况,酶联免疫吸附法(ELISA)检测各组小鼠肺泡灌洗液中白细胞介素-1β(IL-1β)、IL-6、IL-18及肿瘤坏死因子-α(TNF-α)含量,免疫荧光染色观察各组小鼠肺组织内核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)荧光表达,蛋白质免疫印记(Western blotting)检测各组小鼠肺组织中HMGB1及NLRP3、凋亡相关斑点样蛋白(ASC)、含半胱氨酸的天冬氨酸蛋白水解酶-1(Caspase-1)、gasdermin D(GSDMD)的蛋白表达水平。结果与对照组比较,MRL/lpr组小鼠肺组织呈现严重病理损伤症状,胶原纤维沉积面积显著增加(P<0.05),肺泡灌洗液中IL-1β、IL-6、IL-18、TNF-α含量显著升高(P<0.05),肺组织内NLRP3平均荧光强度显著增加(P<0.05),HMGB1蛋白相对表达量及NLRP3、ASC、Caspase-1、GSDMD蛋白相对表达量均显著上调(P<0.05);与MRL/lpr组比较,MRL/lpr+anti-HMGB1组和MRL/lpr+MCC950组小鼠肺组织损伤得到明显改善,胶原纤维沉积面积显著减少(P<0.05),肺泡灌洗液中IL-1β、IL-6、IL-18、TNF-α含量显著降低(P<0.05),肺组织内NLRP3平均荧光强度显著减小(P<0.05),同时,肺组织中HMGB1蛋白相对表达量及NLRP3、ASC、Caspase-1、GSDMD蛋白相对表达量均显著下调(P<0.05)。结论HMGB1中和抗体能够改善SLE模型小鼠肺损伤,该作用可能是通过抑制细胞焦亡实现的。

血清HMGB1、CCL20、HSP27水平与慢性牙周炎患者牙周病变程度的相关性分析

目的探讨血清高迁移率族蛋白1(HMGB1)、CC趋化因子配体20(CCL20)、热休克蛋白27(HSP27)水平与慢性牙周炎(CP)患者牙周病变程度的相关性。方法选取2021年9月至2023年8月在新乡医学院第一附属医院诊治的60例CP患者纳入观察组,根据1∶1原则,另选取同期牙周健康者60例纳入对照组。比较两组及不同牙周病变程度CP患者血清HMGB1、CCL20、HSP27水平,分析各指标水平与CP牙周病变程度的相关性及联合诊断价值,并分析不同血清水平患者发生CP的危险度。结果观察组血清HMGB1、CCL20、HSP27水平高于对照组(P<0.05);不同牙周病变程度CP患者血清HMGB1、CCL20、HSP27水平比较:轻度<中度<重度,且各指标水平与牙周病变程度均呈正相关(P<0.05);入院时HMGB1、CCL20、HSP27水平联合诊断CP的曲线下面积(AUC)为0.905,最佳诊断敏感度为91.67%,特异度为88.33%,约登指数0.800,且各指标高水平患者发生CP的危险度是低水平的1.105倍、1.034倍、1.105倍(P<0.05)。结论HMGB1、CCL20、HSP27在CP患者血清中呈异常高表达,各指标水平与牙周病变程度均呈正相关,且联合检测对CP具有较高诊断价值,可作为临床诊断CP、评估牙周病变程度的有效指标。