HMGB1 is involved in viral replication and the inflammatory response in coxsackievirus A16-infected 16HBE cells via proteomic analysis and identification.

Coxsackievirus A16 (CV-A16) is still an important pathogen that causes hand, foot and mouth disease (HFMD) in young children and infants worldwide. Previous studies indicated that CV-A16 infection is usually mild or self-limiting, but it was also found that CV-A16 infection can trigger severe neurological complications and even death. However, there are currently no vaccines or antiviral compounds available to either prevent or treat CV-A16 infection. Therefore, investigation of the virus‒host interaction and identification of host proteins that play a crucial regulatory role in the pathogenesis of CV-A16 infection may provide a novel strategy to develop antiviral drugs. Here, to increase our understanding of the interaction of CV-A16 with the host cell, we analyzed changes in the proteome of 16HBE cells in response to CV-A16 using tandem mass tag (TMT) in combination with LC‒MS/MS. There were 6615 proteins quantified, and 172 proteins showed a significant alteration during CV-A16 infection. These differentially regulated proteins were involved in fundamental biological processes and signaling pathways, including metabolic processes, cytokine‒cytokine receptor interactions, B-cell receptor signaling pathways, and neuroactive ligand‒receptor interactions. Further bioinformatics analysis revealed the characteristics of the protein domains and subcellular localization of these differentially expressed proteins. Then, to validate the proteomics data, 3 randomly selected proteins exhibited consistent changes in protein expression with the TMT results using Western blotting and immunofluorescence methods. Finally, among these differentially regulated proteins, we primarily focused on HMGB1 based on its potential effects on viral replication and virus infection-induced inflammatory responses. It was demonstrated that overexpression of HMGB1 could decrease viral replication and upregulate the release of inflammatory cytokines, but deletion of HMGB1 increased viral replication and downregulated the release of inflammatory cytokines. In conclusion, the results from this study have helped further elucidate the potential molecular pathogenesis of CV-A16 based on numerous protein changes and the functions of HMGB1 Found to be involved in the processes of viral replication and inflammatory response, which may facilitate the development of new antiviral therapies as well as innovative diagnostic methods.

Molecular Targets to Alleviate Enteric Neuropathy and Gastrointestinal Dysfunction.

Enteric neuropathy underlies long-term gastrointestinal (GI) dysfunction associated with several pathological conditions. Our previous studies have demonstrated that structural and functional changes in the enteric nervous system (ENS) result in persistent alterations of intestinal functions long after the acute insult. These changes lead to aberrant immune response and chronic dysregulation of the epithelial barrier. Damage to the ENS is prognostic of disease progression and plays an important role in the recurrence of clinical manifestations. This suggests that the ENS is a viable therapeutic target to alleviate chronic intestinal dysfunction. Our recent studies in preclinical animal models have progressed into the development of novel therapeutic strategies for the treatment of enteric neuropathy in various chronic GI disorders. We have tested the anti-inflammatory and neuroprotective efficacy of novel compounds targeting specific molecular pathways. Ex vivo studies in human tissues freshly collected after resection surgeries provide an understanding of the molecular mechanisms involved in enteric neuropathy. In vivo treatments in animal models provide data on the efficacy and the mechanisms of actions of the novel compounds and their combinations with clinically used therapies. These novel findings provide avenues for the development of safe, cost-effective, and highly efficacious treatments of GI disorders.

The long intergenic non-protein coding RNA 472 (LINC00472) aggravates neuropathic pain through the microRNA-300/high mobility group box protein 1 axis: a study using the chronic constrictive injury rat model.

BACKGROUND: This study investigated the role and molecular mechanisms of the long intergenic non-protein coding RNA 472 (LINC00472) in neuropathic pain using a chronic constrictive injury (CCI) rat model. METHODS: CCI rat model was established and PC12 cells were induced by LPS to simulate neuropathological injury in vivo and in vitro. The levels of LINC00472, miR-300, and high mobility group box protein 1 (HMGB1) in the spinal cord tissue of CCI rats and PC12 pheochromocytoma cells were assessed by qRT-PCR and western blot. The effects of LINC00472 on neuropathic pain in the CCI rats were observed by their pain behavior. ELISA was used to detect the levels of inflammatory cytokines in rat tissues and cells. The molecular mechanisms of LINC00472 were verified by luciferase experiments, RNA immunoprecipitation, and RNA pull down assays. RESULTS: The expression of LINC00472 and HMGB1 were upregulated, and the expression of miR-300 was downregulated in the spinal cord tissues of CCI rats and in PC12 cells. The upregulation of LINC00472 in CCI rats significantly induced the occurrence of neuropathic pain. In addition, downregulation of LINC00472 inhibited the inflammatory response of CCI rats and PC12 cells. This study identified miR-300 as a target gene of LINC00472, and HMGB1 as the target gene of miR-300. Further experiments confirmed that the expression of anti-miR-300 could partially reverse the anti-inflammatory effects and the reduction of neuropathic pain induced by low expression of LINC00472. CONCLUSIONS: LINC00472 promotes the progression of neuropathic pain by reducing miR-300 expression and increasing HMGB1 expression. The LINC00472/miR-300/HMGB1 axis may be a novel therapeutic target for neuropathic pain.

The MIR155 host gene/microRNA-627/HMGB1/NF-κB loop modulates fibroblast proliferation and extracellular matrix deposition.

Pulmonary fibrosis (PF), which is characterized by excessive matrix formation, may ultimately lead to irreversible lung damage and thus death. Fibroblast activation has been regarded as a central event during PF pathogenesis. In our previous study, we confirmed that the miR-627/high-mobility group box protein 1 (HMGB1)/Nuclear factor kappa beta (NF-κB) axis modulates transforming growth factor beta 1 (TGFß1)-induced pulmonary fibrosis. In the present study, we investigated the upstream factors leading to miR-627 dysregulation in the process of pulmonary fibroblast activation and PF. The lncRNA MIR155 host gene (MIR155HG) was found to be abnormally upregulated in pulmonary fibrosis tissues and TGFß1-stimulated normal human primary lung fibroblasts (NHLFs). By directly binding to miR-627, MIR155HG inhibited miR-627 expression. MIR155HG overexpression enhanced TGFß1-induced increases in HMGB1 protein expression and p65 phosphorylation, NHLF proliferation, and extracellular matrix (ECM) deposition. In contrast, miR-627 overexpression attenuated the TGFß1-induced changes in NHLFs and significantly reversed the effects of MIR155HG overexpression. Under TGFß1 stimulation, miR-627 inhibition promoted, whereas JSH-23 treatment inhibited NF-κB activation; in NHLFs, NF-κB overexpression upregulated, whereas JSH-23 treatment downregulated MIR155HG expression. In tissue samples, HMGB1 protein levels and p65 phosphorylation were increased; MIR155HG was negatively correlated with miR-627 and positively correlated with HMGB1. In conclusion, we validated that the MIR155HG/miR-627/HMGB1/NF-κB axis formed a regulatory loop that modulates TGFß1-induced NHLF activation. Considering the critical role of NHLF activation in PF pathogenesis, the NF-κB/MIR155HG/miR-627/HMGB1 regulatory loop could exert a vital effect on PF pathogenesis. Further in vivo and clinical investigations are required to confirm this model.

Glycyrrhizin Prevents Hemorrhagic Transformation and Improves Neurological Outcome in Ischemic Stroke with Delayed Thrombolysis Through Targeting Peroxynitrite-Mediated HMGB1 Signaling.

Peroxynitrite (ONOO-) and high mobility group box 1 protein (HMGB1) are important cytotoxic factors contributing to cerebral ischemia-reperfusion injury. However, the roles of ONOO- in mediating HMGB1 expression and its impacts on hemorrhagic transformation (HT) in ischemic brain injury with delayed t-PA treatment remain unclear. In the present study, we tested the hypothesis that ONOO- could directly mediate the activation and release of HMGB1 in ischemic brains with delayed t-PA treatment. With clinical studies, we found that plasma nitrotyrosine (NT, a surrogate marker of ONOO-) was positively correlated with HMGB1 level in acute ischemic stroke patients. Hemorrhagic transformation and t-PA-treated ischemic stroke patients had increased levels of nitrotyrosine and HMGB1 in plasma. In animal experiments, we found that FeTmPyP, a representative ONOO- decomposition catalyst (PDC), significantly reduced the expression of HMGB1 and its receptor TLR2, and inhibited MMP-9 activation, preserved collagen IV and tight junction claudin-5 in ischemic rat brains with delayed t-PA treatment. ONOO- donor SIN-1 directly induced expression of HMGB1 and its receptor TLR2 in naive rat brains in vivo and induced HMGB1 in brain microvascular endothelial b.End3 cells in vitro. Those results suggest that ONOO- could activate HMGB1/TLR2/MMP-9 signaling. We then addressed whether glycyrrhizin, a natural HMGB1 inhibitor, could inhibit ONOO- production and the antioxidant properties of glycyrrhizin contribute to the inhibition of HMGB1 and the neuroprotective effects on attenuating hemorrhagic transformation in ischemic stroke with delayed t-PA treatment. Glycyrrhizin treatment downregulated the expressions of NADPH oxidase p47 phox and p67 phox and iNOS, inhibited superoxide and ONOO- production, reduced the expression of HMGB1, TLR2, MMP-9, preserved type IV collagen and claudin-5 in ischemic brains. Furthermore, glycyrrhizin significantly decreased the mortality rate, attenuated hemorrhagic transformation, brain swelling, blood-brain barrier damage, neuronal apoptosis, and improved neurological outcomes in the ischemic stroke rat model with delayed t-PA treatment. In conclusion, peroxynitrite-mediated HMGB1/TLR2 signaling contributes to hemorrhagic transformation, and glycyrrhizin could be a potential adjuvant therapy to attenuate hemorrhagic transformation, possibly through inhibiting the ONOO-/HMGB1/TLR2 signaling cascades.

Targeting high-mobility group box protein 1 (HMGB1) in pediatric traumatic brain injury: Chronic neuroinflammatory, behavioral, and epileptogenic consequences.

High mobility group box protein-1 (HMGB1) has been implicated as a key mediator of neuroinflammation and neurodegeneration in a range of neurological conditions including traumatic brain injury (TBI) and epilepsy. To date, however, most studies have examined only acute outcomes, and the adult brain. We have recently demonstrated HMGB1 release after experimental TBI in the pediatric mouse. This study therefore examined the chronic consequences of acute HMGB1 inhibition in the same model, to test the hypothesis that HMGB1 is a pivotal mediator of neuropathological, neurobehavioral, and epilepsy outcomes in pediatric TBI. HMGB1 was inhibited by treatment with 50 mg/kg i.p. Glycyrrhizin (Gly), compared to vehicle controls, commencing 1 h prior to moderate TBI or sham surgery in post-natal day 21 mice. We first demonstrated that Gly reduced brain HMGB1 levels and brain edema at an acute time point of 3 days post-injury. Subsequent analysis over a chronic time course found that pediatric TBI resulted in short-term spatial memory and motor learning deficits alongside an apparent increase in hippocampal microglial reactivity, which was prevented in Gly-treated TBI mice. In contrast, Gly treatment did not reduce the severity of evoked seizures, the proportion of animals exhibiting chronic spontaneous seizure activity, or cortical tissue loss. Together, our findings contribute to a growing appreciation for HMGB1's role in neuropathology and associated behavioral outcomes after TBI. However, further work is needed to fully elucidate the contribution of HMGB1 to epileptogenesis in this context.

miR-627/HMGB1/NF-κB regulatory loop modulates TGF-ß1-induced pulmonary fibrosis.

Pulmonary fibrosis (PF) is a fibroproliferative disease that can eventually lead to fatal lung failure. It is characterized by abnormal proliferation of fibroblasts, dysregulated fibroblast differentiation to myofibroblast, and disorganized collagen and extracellular matrix production, deposition and degradation. There is still a lack of effective treatment strategies for PF. Extracellular high-mobility group box protein 1 (HMGB1) induces PF through NF-κB-mediated TGF-ß1 release. Herein, we first validate the suppressive effect of HMGB1 knockdown on TGF-ß1-induced α-smooth muscle actin (α-SMA) and collagen I protein expression. In PF, miRNAs exert different effects through targeting various downstream target messenger RNAs. We searched an online database for dysregulated miRNAs in PF tissues; among them, miR-627 was predicted by online tools to target HMGB1 to inhibit its expression. miR-627 overexpression could partially reverse TGF-ß1-induced normal human lung fibroblast proliferation, as well as α-SMA and collagen I protein expression. miR-627 inhibition could partially reverse the suppressive effect of HMGB1 knockdown on TGF-ß1-induced α-SMA and collagen I protein expression through direct binding to the 3'-untranslated region of HMGB1. Moreover, miR-627/HMGB1 affected TGF-ß1 release through RAGE/NF-κB signaling; miR-627/HMGB1 and RAGE/NF-κB signaling formed a regulatory loop to modulate TGF-ß1-induced PF in vitro. In conclusion, miR-627 may be a potential agent that targets HMGB1 to inhibit its expression, thereby improving TGF-ß1-induced PF in vitro.

Mesothelioma: recent highlights.

Recent discoveries have elucidated some of the mechanisms responsible for the development of mesothelioma. These discoveries are: (I) the critical role of chronic inflammation in promoting mesothelioma growth, driven by the release of high mobility group box protein-1 (HMGB1) following asbestos deposition in tissues and its potential role as a biomarker to identify asbestos exposed individuals and mesothelioma patients; (II) the discovery that inherited heterozygous germline mutations of the deubiquitylase BRCA-associated protein 1 (BAP1) cause a high incidence of mesothelioma in some families; and that (III) germline BAP1 mutations lower the threshold of asbestos required to cause mesothelioma in mice, evidence of gene X environment interaction. These findings together with the identification of novel serum biomarkers, including HMGB1, Fibulin-3, etc., promise to revolutionize screening and treatment of this malignancy in the coming years.

High mobility group box protein 1-A prognostic marker for structural joint damage in 10-year follow-up of patients with juvenile idiopathic arthritis.

OBJECTIVE: High mobility group box protein 1 (HMGB1) is an important pro-inflammatory mediator in adult rheumatoid arthritis. The diagnostic utility of HMGB1 in Juvenile Idiopathic Arthritis (JIA) is still unclear. The aim was to examine whether serum HMGB1 levels are associated with inflammation, radiological disease progression, and long-term prognosis in JIA. METHODS: We included 131 children with JIA from a population-based prevalence study; 38 of them were prospectively followed up for 10 years. Clinical and laboratory disease characteristics at study entry and after 10 years as well as radiological progression over 10 years were recorded. HMGB1 levels were analyzed by an ELISA. RESULTS: The HMGB1 levels were similar in children with different JIA subgroups and in children with established (53%) or newly diagnosed (47%) disease. HMGB1 levels did not differ between groups at entry into the study or at 10 years, by sex, or by the presence or absence of RF or ANA antibodies. HMGB1 levels at the study entry correlated with HMGB1 levels at 10 years and with blood neutrophil count. Most importantly, children with destructive arthritis at 10 years had a tendency toward higher HMGB1 levels at study entry (median 1.2 vs 0.6ng/ml, ns) and displayed 4-fold higher circulating HMGB1 levels (median 3.4 vs 0.8ng/ml, p = 0.0014) than children without radiological destructions. CONCLUSIONS: Our results suggest that HMGB1 is a marker of inflammatory activity in children with JIA. Higher serum HMGB1 levels are related to more destructive JIA and could be used as a negative prognostic marker at the disease start. TRIAL REGISTRATION: Clinicaltrials.gov NCT01905319. Registered July 16, 2013.

Transplantation of umbilical cord mesenchymal stem cells alleviates pneumonitis of MRL/lpr mice.

OBJECTIVE: To investigate whether the umbilical cord mesenchymal stem cells (UC-MSCs) transplantation in the MRL/lpr mice has effect or not on their pneumonitis and the possible mechanisms underlying this treatment. METHODS: Twenty four 18-week-old MRL/lpr female mice were divided into three groups as following: the group 2 (UC-MSCT group) have been transplanted with 1×10(6) UC-MSCs through caudal vein, the group 3 (multi-UC-MSCT Group) have been transplanted with 1×10(6) UC-MSCs three times and the group 1 (control group) have been treated with 0.5 mL phosphate buffer saline (PBS) as control. The histopathology of the lung was observed. The pulmonary expression of high mobility group box protein-1 (HMGB-1) was measured by western blot and detected by quantitation real time polymerase chain reaction (PCR). Immunohistochemistry method was used to detect HMGB-1 expressions in pulmo. RESULTS: In comparision to control ground mice, UC-MSCs significantly reduced interstitial pneumonitis in the MRL/lpr mice. The lung peribronchiolar lesion index of UC-MSCT group (1.40±0.24) and multi-UC-MSCT group (1.02±0.29) were significantly decreased as compared to control group (1.95±0.35) (P<0.01). The perivascular lesion index of UC-MSCT group (1.20±0.18) and multi-UC-MSCT group (1.08±0.16) were also significantly reduced as compared to control group (1.56±0.32) (P=0.018, 0.002) and the lung alveolar areas lesion index of control group (1.72±0.34) was significantly increased as compared to UC-MSCT group (1.30±0.21) and multi-UC-MSCT group (1.05±0.15) (P=0.011, 0.000). The lung HMGB-1 protein in UC-MSCT group (0.32±0.04) and in multi-UC-MSCT group (0.28±0.06) were both significantly decreased as compared to that in control group (0.80±0.21) (P<0.05). The level of HMGB-1 mRNA in UC-MSCT group (4.68±0.37) and in multi-UC-MSCT group (4.35±0.10) lung were both significantly decreased as compared to those in control group (16.29±3.84) (P<0.05). In immunohistochemical staining lung sections, high expression of HMGB-1 was found mainly located in the cytoplasm and extracellular matrix of MRL/lpr mice pulmonary epithelial cells, the expression of HMGB-1 in UC-MSCT group and multi-UC-MSCT group was significantly decreased as compared to that in the control group. CONCLUSIONS: These findings indicate that UC-MSCs have a therapeutic effect on systemic lupus erythematosus (SLE) pneumonitis, possibly by inhibiting HMGB-1 expression, which suggests a potential application of UC-MSCs in the treatment of human lupus.