Autophagy is a catabolic process critical to maintaining cellular homeostasis and responding to cytotoxic insult. Autophagy is recognized as "programmed cell survival" in contrast to apoptosis or programmed cell death. Upregulation of autophagy has been observed in many types of cancers and has been demonstrated to both promote and inhibit antitumor drug resistance depending to a large extent on the nature and duration of the treatment-induced metabolic stress as well as the tumor type. Cisplatin, doxorubicin and methotrexate are commonly used anticancer drugs in osteosarcoma, the most common form of childhood and adolescent cancer. Our recent study demonstrated that high mobility group box 1 protein (HMGB1)-mediated autophagy is a significant contributor to drug resistance in osteosarcoma cells. Inhibition of both HMGB1 and autophagy increase the drug sensitivity of osteosarcoma cells in vivo and in vitro. Furthermore, we demonstrated that the ULK1-FIP200 complex is required for the interaction between HMGB1 and BECN1, which then promotes BECN1-PtdIns3KC3 complex formation during autophagy. Thus, these findings provide a novel mechanism of osteosarcoma resistance to therapy facilitated by HMGB1-mediated autophagy and provide a new target for the control of drug-resistant osteosarcoma patients.

High mobility group box 1 (HMGB1) is a NF released extracellularly as a late mediator of lethality in sepsis and as an early mediator of inflammation following injury. Here we demonstrate that in contrast to the proinflammatory role of HMGB1, preconditioning with HMGB1 results in protection following hepatic ischemia/reperfusion (I/R). Pretreatment of mice with HMGB1 significantly decreased liver damage after I/R. The protection observed in mice pretreated with HMGB1 was associated with a higher expression of IL-1R-associated kinase-M, a negative regulator of TLR4 signaling, compared with controls. We thus explored the possibility that HMGB1 preconditioning was mediated through TLR4 activation. HMGB1 preconditioning failed to provide protection in TLR4 mutant (C3H/HeJ) mice, but successfully reduced damage in TLR4 wild-type (C3H/HeOuj) mice. Our studies demonstrate that in contrast to the role of HMGB1 as an early mediator of inflammation and organ damage in hepatic I/R, HMGB1 preconditioning can be protective.

Sepsis is a systemic inflammatory response to infection that causes severe neurological complications. Previous studies have suggested that melatonin is protective during sepsis. Additionally, silent information regulator 1 (SIRT1) was reported to be beneficial in sepsis. However, the role of SIRT1 signaling in the protective effect of melatonin against septic encephalopathy remains unclear. This study aimed to investigate the role of SIRT1 in the protective effect of melatonin. EX527, a SIRT1 inhibitor, was used to reveal the role of SIRT1 in melatonin's action. Cecal ligation and puncture or sham operation was performed in male C57BL/6J mice. Melatonin was administrated intraperitoneally (30 mg/kg). The survival rate of mice was recorded for the 7-day period following the sham or CLP operation. The blood-brain barrier (BBB) integrity, brain water content, levels of inflammatory cytokines (TNF-α, IL-1β, and HMGB1), and the level of oxidative stress (superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA)) and apoptosis were assessed. The expression of SIRT1, Ac-FoxO1, Ac-p53, Ac-NF-κB, Bcl-2, and Bax was detected by Western blot. The results suggested that melatonin improved survival rate, attenuated brain edema and neuronal apoptosis, and preserved BBB integrity. Melatonin decreased the production of TNF-α, IL-1β, and HMGB1. Melatonin increased the activity of SOD and CAT and decreased the MDA production. Additionally, melatonin upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of Ac-FoxO1, Ac-p53, Ac-NF-κB, and Bax. However, the protective effects of melatonin were abolished by EX527. In conclusion, our results demonstrate that melatonin attenuates sepsis-induced brain injury via SIRT1 signaling activation.

Sepsis is a deadly inflammatory syndrome caused by an exaggerated immune response to infection. Much has been focused on host response to pathogens mediated through the interaction of pathogen-associated molecular patterns (PAMPs) and pattern recognition receptors (PRRs). PRRs are also activated by host nuclear, mitochondrial, and cytosolic proteins, known as damage-associated molecular patterns (DAMPs) that are released from cells during sepsis. Some well described members of the DAMP family are extracellular cold-inducible RNA-binding protein (eCIRP), high mobility group box 1 (HMGB1), histones, and adenosine triphosphate (ATP). DAMPs are released from the cell through inflammasome activation or passively following cell death. Similarly, neutrophil extracellular traps (NETs) are released from neutrophils during inflammation. NETs are webs of extracellular DNA decorated with histones, myeloperoxidase, and elastase. Although NETs contribute to pathogen clearance, excessive NET formation promotes inflammation and tissue damage in sepsis. Here, we review DAMPs and NETs and their crosstalk in sepsis with respect to their sources, activation, release, and function. A clear grasp of DAMPs, NETs and their interaction is crucial for the understanding of the pathophysiology of sepsis and for the development of novel sepsis therapeutics.

OBJECTIVE

Type 1 diabetes is a proinflammatory state characterised by increased levels of circulating biomarkers of inflammation and monocyte activity. We have shown increased Toll-like receptor 2 (TLR2) and TLR4 expression and signalling in monocytes from type 1 diabetic patients. Several endogenous ligands of TLR2 and TLR4 have been identified; however, there is a paucity of data on levels of these endogenous ligands in diabetes. Thus, the aim of this study was to examine circulating levels of exogenous/endogenous ligands of TLR2 and TLR4 in type 1 diabetic patients and to compare these with the levels in matched healthy controls.

METHODS

Healthy controls (n = 37) and type 1 diabetic patients (n = 34) were recruited, and a fasting blood sample was obtained. Circulating levels of endotoxin, heat-shock protein 60 (Hsp60), high-mobility group box 1 (HMGB1) and growth arrest-specific 6 (GAS6) proteins were assessed by ELISA, and TLR2 and TLR4 expression was determined by flow cytometry.

RESULTS

Levels of the classical TLR4 ligand, endotoxin, were significantly elevated in type 1 diabetic patients compared with those in matched controls. Hsp60 and HMGB1 concentrations were also significantly increased in the patients (p < 0.01 and p < 0.001, respectively). No significant differences were observed in GAS6.

CONCLUSIONS

We report the novel observation that levels of ligands of TLR2 and TLR4 are significantly elevated in type 1 diabetes, and this, in concert with hyperglycaemia, accounts for the increase in TLR2 and TLR4 activity, underscoring the proinflammatory state of type 1 diabetes.

Interaction of the pattern recognition receptor, RAGE with key ligands such as advanced glycation end products (AGE), S100 proteins, amyloid β, and HMGB1 has been linked to diabetic complications, inflammatory and neurodegenerative disorders, and cancer. To help answer the question of how a single receptor can recognize and respond to a diverse set of ligands we have investigated the structure and binding properties of the first two extracellular domains of human RAGE, which are implicated in various ligand binding and subsequent signaling events. The 1.5-Å crystal structure reveals an elongated molecule with a large basic patch and a large hydrophobic patch, both highly conserved. Isothermal titration calorimetry (ITC) and deletion experiments indicate S100B recognition by RAGE is an entropically driven process involving hydrophobic interaction that is dependent on Ca(2+) and on residues in the C'D loop (residues 54-67) of domain 1. In contrast, competition experiments using gel shift assays suggest that RAGE interaction with AGE is driven by the recognition of negative charges on AGE-proteins. We also demonstrate that RAGE can bind to dsDNA and dsRNA. These findings reveal versatile structural features of RAGE that help explain its ability to recognize of multiple ligands.

Safe and efficient drugs to combat the current COVID-19 pandemic are urgently needed. In this context, we have analyzed the anti-coronavirus potential of the natural product glycyrrhizic acid (GLR), a drug used to treat liver diseases (including viral hepatitis) and specific cutaneous inflammation (such as atopic dermatitis) in some countries. The properties of GLR and its primary active metabolite glycyrrhetinic acid are presented and discussed. GLR has shown activities against different viruses, including SARS-associated Human and animal coronaviruses. GLR is a non-hemolytic saponin and a potent immuno-active anti-inflammatory agent which displays both cytoplasmic and membrane effects. At the membrane level, GLR induces cholesterol-dependent disorganization of lipid rafts which are important for the entry of coronavirus into cells. At the intracellular and circulating levels, GLR can trap the high mobility group box 1 protein and thus blocks the alarmin functions of HMGB1. We used molecular docking to characterize further and discuss both the cholesterol- and HMG box-binding functions of GLR. The membrane and cytoplasmic effects of GLR, coupled with its long-established medical use as a relatively safe drug, make GLR a good candidate to be tested against the SARS-CoV-2 coronavirus, alone and in combination with other drugs. The rational supporting combinations with (hydroxy)chloroquine and tenofovir (two drugs active against SARS-CoV-2) is also discussed. Based on this analysis, we conclude that GLR should be further considered and rapidly evaluated for the treatment of patients with COVID-19.

Keywords: COVID-19; Cholesterol; Coronavirus; Glycyrrhizin; HMGB1; Natural product.

BACKGROUND

High-mobility group box chromosomal protein 1 (HMGB1) has recently been shown to be an important late mediator of endotoxin shock, intraabdominal sepsis, and acute lung injury, and a promising therapeutic target of severe sepsis. We sought to investigate the effect of antibodies to HMGB1 on severe sepsis in a rat cecal ligation and puncture (CLP) model.

METHODS

Adult male Sprague-Dawley rats underwent CLP and then were randomly divided into two groups: treatment with anti-HMGB1 polyclonal antibodies, and non-immune IgG-treated controls. The serum HMGB1 concentrations were measured at ten time points (preoperatively, and postoperatively at 4, 8, 20, 32, and 48 h and at 3, 4, 5, and 6 days). Hematoxylin-eosin staining, elastica-Masson staining, and immunohistochemical staining for HMGB1 were performed on the cecum and the lung to assess pathological changes 24 h after the CLP procedure.

RESULTS

Treatment with anti-HMGB1 antibodies significantly increased survival [55% (anti-HMGB1) vs. 9% (controls); P< 0.01]. The serum HMGB1 concentrations at postoperative hours 20 and 32 of the anti-HMGB1 antibody-treated animals were significantly lower than those of the controls (P < 0.05). Treatment with anti-HMGB1 antibodies markedly diminished the pathological changes and the number of HMGB1-positive cells in the cecum and the lung.

CONCLUSIONS

The present study demonstrates that anti-HMGB1 antibodies are effective in the treatment of severe sepsis in a rat model, thereby supporting the relevance of HMGB1 eradication therapy for severe sepsis.

Recent evidence suggests that inflammatory molecules play critical roles in the development and progression of numerous tumors. However, one specific group of inflammatory molecules whose importance has been established in host immune responses, termed alarmins, has been largely overlooked in cancer biology. The function of several alarmins-including the defensins, LL-37, and HMGB1-in tumor development, progression, or suppression is discussed here. Taken together, these studies indicate that alarmins represent potential new targets for manipulation in a variety of tumors.

HMGB1 finely tunes the function of DCs, thus influencing their maturation program and eventually the establishment of adaptive, T cell-dependent immune responses. Moreover, it promotes the up-regulation of receptors for lymph node chemokines, regulates the remodeling of the cytoskeleton of migrating cells, and sustains their journey to secondary lymphoid organs via a RAGE-dependent pathway. The inflammatory properties of HMGB1 depend at least partially on the ability to complex with soluble moieties, including nucleic acids, microbial products, and cytokines. Here, we show that bone marrow-derived mouse DCs release HMGB1 during CXCL12-dependent migration in vitro. Macrophages share this property, suggesting that it may be a general feature of CXCL12-responsive leukocytes. The chemotactic response to rCXCL12 of DCs and macrophages abates in the presence of the HMGB1 antagonist BoxA. HMGB1 secreted from DCs and macrophages binds to CXCL12 in the fluid phase and protects the chemokine conformation and function in a reducing environment. Altogether, our data indicate that HMGB1 release is required for CXCL12 ability to attract myeloid-derived cells and reveal a functional interaction between the two molecules that possibly contributes to the regulation of leukocyte recruitment and motility.

High mobility group box 1 (HMGB1) is a versatile protein with intranuclear and extracellular functions that is involved in numerous biological and pathological processes, such as transcription, DNA repair, and response to infection and inflammation. The expression of HMGB1 has been described in many types of cancers, but the role of HMGB1 in nasopharyngeal carcinoma (NPC) is unknown. The aim of this study was to analyse the roles of HMGB1 in NPC progression and clinical outcome using NPC clinical samples. In an immunohistochemical study, HMGB1 had high expression in 89 of 166 cases of NPC (53.6%). HMGB1 overexpression was significantly associated with T classification (p = 0.01), N classification (p = 0.003), distant metastasis (p = 0.046), and clinical stage (p < 0.001). Patients with higher levels of HMGB1 expression had poorer overall survival and disease-free survival, whereas patients with lower levels of HMGB1 expression had better survival. Multivariate analysis showed that HMGB1 expression was an independent prognostic indicator for patient survival. Disruption of endogenous HMGB1 using small interfering RNAs suppressed NPC cell invasive ability. These data support the notion that HMGB1 overexpression has a role in the progression of NPC and hence its poor clinical outcome.

Adolescence is characterized behaviorally by increased impulsivity and risk-taking that declines in parallel with maturation of the prefrontal cortex and executive function. In the brain, the receptor for advanced glycation end products (RAGE) is critically involved in neurodevelopment and neuropathology. In humans, the risk of alcoholism is greatly increased in those who begin drinking between 13 and 15years of age, and adolescents binge drink more than any other age group. We have previously found that alcoholism is associated with increased expression of neuroimmune genes. This manuscript tested the hypothesis that adolescent binge drinking upregulates RAGE and Toll-like receptor (TLR) 4 as well as their endogenous agonist, high-mobility group box 1 (HMGB1). Immunohistochemistry, Western blot, and mRNA analyses found that RAGE expression was increased in the human post-mortem alcoholic orbitofrontal cortex (OFC). Further, an earlier age of drinking onset correlated with increased expression of RAGE, TLR4, and HMGB1. To determine if alcohol contributed to these changes, we used an adolescent binge ethanol model in rats (5.0g/kg, i.g., 2-day on/2-day off from postnatal day [P] 25 to P55) and assessed neuroimmune gene expression. We found an age-associated decline of RAGE expression from late adolescence (P56) to young adulthood (P80). Adolescent intermittent ethanol exposure did not alter RAGE expression at P56, but increased RAGE in the young adult PFC (P80). Adolescent intermittent ethanol exposure also increased TLR4 and HMGB1 expression at P56 that persisted into young adulthood (P80). Assessment of young adult frontal cortex mRNA (RT-PCR) found increased expression of proinflammatory cytokines, oxidases, and neuroimmune agonists at P80, 25days after ethanol treatment. Together, these human and animal data support the hypothesis that an early age of drinking onset upregulates RAGE/TLR4-HMGB1 and other neuroimmune genes that persist into young adulthood and could contribute to risk of alcoholism or other brain diseases associated with neuroinflammation.

HMGB1 is an architectural factor that enhances the DNA binding affinity of several proteins. We have investigated the influence of HMGB1 on DNA binding by members of the Rel family. HMGB1 enhances DNA binding by p65/p50 and p50/p50, but reduces binding by p65/p65, c-Rel/c-Rel, p65/c-Rel, and p50/c-Rel. In pull-down assays, HMGB1 interacts directly with the p50 subunit via its HMG boxes and this interaction is weakened by the presence of the acidic tail. Functionally, HMGB1 is required for the NF-kappaB-dependent expression of the adhesion molecule VCAM-1.

Sepsis is a devastating condition characterized by a systemic inflammatory response. Recently, high mobility group box 1 (HMGB1) was identified as a necessary and sufficient mediator of the lethal systemic inflammation caused by sepsis. However, despite its clinical importance, the mechanism of HMGB1 release has remained to be elusive. In this study, we demonstrate that the IFN-beta-mediated JAK/STAT pathway is essential for LPS or Escherichia coli-induced HMGB1 release, which is dependent on Toll/IL-1R domain-containing adapter-inducing IFN-beta adaptor. Additionally, we show that NO acts as a downstream molecule of the IFN-beta signaling. Furthermore, the JAK inhibitor treatment as well as the STAT-1 or IFN-beta receptor deficiency reduced HMGB1 release in a murine model of endotoxemia. Our results suggest that HMGB1 release in sepsis is dependent on the IFN-beta signaling axis; thus, therapeutic agents that selectively inhibit IFN-beta signaling could be beneficial in the treatment of sepsis.

OBJECTIVE

To study the predictive value of high mobility group box-1 protein (HMGB1) and hospital mortality in adult patients with severe sepsis.

METHODS

Prospective observational cohort study in 24 ICUs in Finland.

METHODS

Two hundred and forty-seven adult patients with severe sepsis.

RESULTS

Blood samples for HMGB1 analyses were drawn from 247 patients at baseline and from 210 patients 72 h later. The mean APACHE II and SAPS II scores were 24 (SD 9) and 44 (SD 17), respectively. The hospital mortality was 26%. The serum HMGB1 concentrations were measured first by semi-quantitative Western immunoblotting (WB) analysis. The median HMGB1 concentration on day 0 was 108% (IQR 98.5-119) and after 72 h 107% (IQR 98.8-120), which differed from healthy controls (97.5%, IQR 91.3-106.5; p=0.028 and 0.019, respectively). The samples were re-analysed by ELISA (in a subgroup of 170 patients) to confirm the results by WB. The median concentration in healthy controls was 0.65 ng/ml (IQR 0.51-1.0). This was lower than in patients with severe sepsis (3.6 ng/ml, IQR 1.9-6.5, p< 0.001). HMGB1 concentrations (WB and ELISA) did not differ between hospital survivors and non-survivors. In ROC analyses for HMGB1 levels (WB) on day 0 and 72 h with respect to hospital mortality, the areas under the curve were 0.51 and 0.56 (95% CI 0.40-0.61 and 0.47-0.65).

CONCLUSIONS

Serum HMGB1 concentrations were elevated in patients with severe sepsis, but did not differ between survivors and non-survivors and did not predict hospital mortality.

CONCLUSIONS

In the cells' nuclei, high-mobility group box protein 1 (HMGB1) is a nonhistone chromatin-binding protein involved in the regulation of transcription. Extracellularly, HMGB1 acts as a danger molecule with properties of a proinflammatory cytokine. It can be actively secreted from myeloid cells or passively leak from any type of injured, necrotic cell. Increased serum levels of active HMGB1 are often found in pathogenic inflammatory conditions and correlate with worse prognoses in cancer, sepsis, and autoimmunity. By damaging cells, superoxide and peroxynitrite promote leakage of HMGB1.

BACKGROUND

The activity of HMGB1 strongly depends on its redox state: Inflammatory-active HMGB1 requires an intramolecular disulfide bond (Cys23 and Cys45) and a reduced Cys106. Oxidation of the latter blocks its stimulatory activity and promotes immune tolerance.

RESULTS

Reactive oxygen and nitrogen species create an oxidative environment and can be detoxified by superoxide dismutase (SOD), catalase, and peroxidases. Modifications of the oxidative environment influence HMGB1 activity.

CONCLUSIONS

In this review, we hypothesize that manipulations of an oxidative environment by SOD mimics or by hydrogen sulfide are prone to decrease tissue damage. Both the concomitant decreased HMGB1 release and its redox chemical modifications ameliorate inflammation and tissue damage.

The receptor for advanced glycation end products (RAGE), a multiligand receptor of the immunoglobulin superfamily, has been implicated in the inflammatory response, diabetic angiopathy and neuropathy, neurodegeneration, cell migration, tumor growth, neuroprotection, and neuronal differentiation. We show here that (i) RAGE is expressed in skeletal muscle tissue and its expression is developmentally regulated and (ii) RAGE engagement by amphoterin (HMGB1), a RAGE ligand, in rat L6 myoblasts results in stimulation of myogenic differentiation via activation of p38 mitogen-activated protein kinase (MAPK), up-regulation of myogenin and myosin heavy chain expression, and induction of muscle creatine kinase. No such effects were detected in myoblasts transfected with a RAGE mutant lacking the transducing domain or myoblasts transfected with a constitutively inactive form of the p38 MAPK upstream kinase, MAPK kinase 6, Cdc42, or Rac-1. Moreover, amphoterin counteracted the antimyogenic activity of the Ca(2+)-modulated protein S100B, which was reported to inhibit myogenic differentiation via inactivation of p38 MAPK, and basic fibroblast growth factor (bFGF), a known inhibitor of myogenic differentiation, in a manner that was inversely related to the S100B or bFGF concentration and directly related to the extent of RAGE expression. These data suggest that RAGE and amphoterin might play an important role in myogenesis, accelerating myogenic differentiation via Cdc42-Rac-1-MAPK kinase 6-p38 MAPK.

Damage-associated molecular pattern molecules (DAMPs) are endogenous danger signals that alert the innate immune system and shape the inflammation response to cell death. However, the release and activity of DAMPs in ferroptosis, a recently identified form of regulated necrosis characterized by iron overload and lipid peroxidation, still remain poorly understood. Here, we demonstrate that HMGB1 is a DAMP released by ferroptotic cells in an autophagy-dependent manner. Both type I and II ferroptosis activators, including erastin, sorafenib, RSL3, and FIN56, induce HMGB1 release in cancer and noncancer cells. In contrast, genetic ablation (using ATG5^-/- or ATG7^-/- cells) or pharmacologic inhibition (the administration of bafilomycin A1 or chloroquine) of autophagy was found to block ferroptosis activator-induced HMGB1 release. Mechanically, autophagy-mediated HDAC inhibition promotes HMGB1 acetylation, resulting in HMGB1 release in ferroptosis. Moreover, AGER, but not TLR4, is required for HMGB1-mediated inflammation in macrophages in response to ferroptotic cells. These studies suggest that HMGB1 inhibition might have some potential therapeutic effects in ferroptosis-associated human disease.

OBJECTIVE

High-mobility group box 1 (HMGB1) is a versatile protein with intranuclear and extracellular functions that is involved in numerous biological and pathological processes, such as transcription, DNA repair, and response to infection and inflammation. HMGB1 overexpression has been reported in a variety of human cancers. However, the clinical significance of HMGB1 expression in bladder cancer (BC) remains unclear. This study is aimed to investigate the correlations between HMGB1 expression and prognosis in patients with BC.

METHODS

HMGB1 protein expression in 164 primary BC tissue specimens was analyzed by immunohistochemistry, and its association with clinicopathologic factors and prognosis was also analyzed.

RESULTS

HMGB1 protein had high expression in 87 of 164 cases of BC (53%). HMGB1 overexpression was significantly associated with tumor grade (P < 0.001), and stage (P = 0.001). The Kaplan-Meier survival analysis demonstrated that HMGB1 expression was significantly associated with shorter disease-free survival and overall survival (both P < 0.001). Multivariate analysis further demonstrated that HMGB1 was an independent prognostic factor for patients with BC.

CONCLUSIONS

HMGB1 might be a new molecular marker to predict the prognosis of patients with BC.

Chronic lymphocytic leukemia (CLL) is a disease of an accumulation of mature B cells that are highly dependent on the microenvironment for maintenance and expansion. However, little is known regarding the mechanisms whereby CLL cells create their favorable microenvironment for survival. High-mobility group protein B-1 (HMGB1) is a highly conserved nuclear protein that can be actively secreted by innate immune cells and passively released by injured or dying cells. We found significantly increased HMGB1 levels in the plasma of CLL patients compared with healthy controls, and HMGB1 concentration is associated with absolute lymphocyte count. We therefore sought to determine potential roles of HMGB1 in modulating the CLL microenvironment. CLL cells passively released HMGB1, and the timing and concentrations of HMGB1 in the medium were associated with differentiation of nurse-like cells (NLCs). Higher CD68 expression in CLL lymph nodes, one of the markers for NLCs, was associated with shorter overall survival of CLL patients. HMGB1-mediated NLC differentiation involved internalization of both receptor for advanced glycation end products (RAGE) and Toll-like receptor-9 (TLR9). Differentiation of NLCs can be prevented by blocking the HMGB1-RAGE-TLR9 pathway. In conclusion, this study demonstrates for the first time that CLL cells might modulate their microenvironment by releasing HMGB1.

Developmental dyslexia is a common specific childhood learning disorder with a strong heritable component. Previous studies using different genetic approaches have identified several genetic loci and candidate genes for dyslexia. In this article, we have integrated the current knowledge on 14 dyslexia candidate genes suggested by cytogenetic findings, linkage and association studies. We found that 10 of the 14 dyslexia candidate genes (ROBO1, KIAA0319, KIAA0319L, S100B, DOCK4, FMR1, DIP2A, GTF2I, DYX1C1 and DCDC2) fit into a theoretical molecular network involved in neuronal migration and neurite outgrowth. Based on this, we also propose three novel dyslexia candidate genes (SLIT2, HMGB1 and VAPA) from known linkage regions, and we discuss the possible involvement of genes emerging from the two reported genome-wide association studies for reading impairment-related phenotypes in the identified network.

Toll-like receptor (TLR) proteins play key roles in immune responses against infection. Using TLR proteins, host can recognize the conserved molecular structures found in pathogens called pathogen-associated molecular patterns (PAMPs). At the same time, some TLRs are able to detect specific host molecules, such as high-mobility group box protein 1 (HMGB1) and heat shock proteins (hsp), and lead to inflammatory responses. Thus, it has been suggested that TLRs are involved in the development of many pathogenic conditions. Recent advances in TLR-related research not only provide us with scientific information, but also show the therapeutic potential against diseases, such as autoimmune disease and cancer. In this mini review, we demonstrate how TLRs pathways could be involved in cancer development and their therapeutic application, and discuss recent patentable subjects, in particular, that are targeting this unique pathway.

High mobility group box 1 (HMGB1), the prototypic damage-associated molecular pattern molecule, is released at sites of inflammation and/or tissue damage. There, it promotes cytokine production and chemokine production/cell migration. New work shows that the redox status of HMGB1 distinguishes its cytokine-inducing and chemokine activity. Reduced all-thiol-HMGB1 has sole chemokine activity, whereas disulfide-HMGB1 has only cytokine activity, and oxidized, denatured HMGB1 has neither. Autophagy (programmed cell survival) and apoptosis (programmed cell death) have been implicated in controlling both innate and adaptive immune functions. Reduced HMGB1 protein promotes autophagy, whereas oxidized HMGB1 promotes apoptosis. Thus, the differential activity of HMGB1 in immunity, inflammation and cell death depends on the cellular redox status within tissues.

High mobility group box 1 (HMGB1) is a chromatin protein that acts as an immunomodulatory cytokine upon active release from myeloid cells. HMGB1 is also an alarmin, an endogenous molecule released by dying cells that acts to initiate tissue repair. We have previously reported that osteoclasts and osteoblasts release HMGB1 and release by the latter is regulated by parathyroid hormone (PTH), an agent of bone remodeling. A recent study suggests that HMGB1 acts as a chemotactic agent to osteoclasts and osteoblasts during endochondral ossification. To explore the potential impact of HMGB1 in the bone microenvironment and its mechanism of release by osseous cells, we characterized the effects of recombinant protein (rHMGB1) on multiple murine bone cell preparations that together exhibit the various cell phenotypes present in bone. We also inquired whether apoptotic bone cells release HMGB1. rHMGB1 enhanced the RANKL/OPG steady state mRNA ratio and dramatically augmented the release of tumor necrosis factor-alpha (TNFalpha) and interleukin-6 (IL6) in osteoblastogenic bone marrow stromal cell (BMSC) cultures but not in the calvarial-derived MC3T3-E1 cells. Interestingly, rHMGB1 promoted GSK-3beta phosphorylation in MC3T3-E1 cells but not in BMSCs. Apoptotic bone cells released HMGB1, including MLO-Y4 osteocyte-like cells. MLO-Y4 release of HMGB1 was coincident with caspase-3 cleavage. Furthermore, the anti-apoptotic action of PTH on MC3T3-E1 cells correlated with the observed decrease in HMGB1 release. Our data suggest that apoptotic bone cells release HMGB1, that within the marrow HMGB1 is a bone resorption signal, and that intramembraneous and endochondral osteoblasts exhibit differential responses to this cytokine.