Protein phosphatase-1 (PP1) nuclear targeting subunit (PNUTS), also called PP1R10, p99, or CAT 53 was originally isolated as a mammalian nuclear PP1-binding protein. In this study, we performed yeast two-hybrid screens to identify PNUTS-interacting proteins. Here, we report that LCP1 (epidermal Langerhans cell protein 1), a novel member of the HMG-box protein family, binds tightly to PNUTS. Co-immunoprecipitation of deletion constructs revealed that the C-terminus of LCP1 is sufficient for the interaction with an N-terminal region of PNUTS that is distinct from its PP1-binding domain. Furthermore, immunofluorescence studies showed that a subpopulation of LCP1 co-localizes with PNUTS in nuclear speckles. Importantly, we found that the N-terminus of LCP1 has a strong trans-activation activity in a GAL4-based heterologous transcription assay. The transcriptional activity of LCP1 is markedly suppressed by its interaction with PNUTS, in a PP1-independent manner. These findings suggest that the coordinated spatial and temporal regulation of LCP1 and PNUTS may be a novel mechanism to control the expression of genes that are critical for certain physiological and pathological processes.
Amino Acid Sequence ; Cell Line ; Cell Nucleus/*metabolism ; DNA-Binding Proteins/*metabolism ; HMGB Proteins/*metabolism ; Humans ; Molecular Sequence Data ; Nuclear Proteins/*metabolism ; Protein Binding ; Protein Interaction Mapping ; RNA-Binding Proteins/*metabolism ; Transcriptional Activation ; Two-Hybrid System Techniques

OBJECTIVETo investigate the association between high mobility group box1 (HMGB1) and cervical squamous cell carcinoma (CSCC), and explore the role of HMGB1/RAGE pathway in the metastasis of CSCC.

METHODSLevels of HMGB1 mRNA and RAGE mRNA in CSCC and normal cervical tissues were detected by real time quantitative polymerase chain reaction (qRT-PCR), and the level of HMGB1 protein was determined by immunohistochemistry and Western blotting.

RESULTSThe mRNA and protein expression of HMGB1 was significantly higher in CSCC than that in normal cervical tissue (P < 0.05), correlated with stage, invasion and metastasis (P < 0.05), but not with tumor size and differentiation (P > 0.05). The levels of RAGE mRNA and HMGB1 mRNA were both significantly higher (r = 0.663, P < 0.05) in metastatic CSCC in comparison with those in the non-metastatic cases.

CONCLUSIONHMGB1 is involved in the invasion and metastasis of CSCC, and HMGB1/RAGE pathway plays an important role in the metastasis of CSCC.

Blotting, Western ; Carcinoma in Situ ; metabolism ; pathology ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Cervix Uteri ; metabolism ; pathology ; Female ; Gene Expression Regulation, Neoplastic ; HMGB Proteins ; metabolism ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasm Staging ; RNA, Messenger ; metabolism ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Uterine Cervical Neoplasms ; metabolism ; pathology

No abstract available.
HMGB1 Protein* ; Pemphigus*

Humans ; Asthma/diagnosis* ; HMGB1 Protein

HMGB1 is a widely existing DNA-binding nuclear protein, participating in gene transcription, damage repair, recombination and stabilizing nucleosome construction. Under injury, infection and chemotherapy, HMGB1 can be released by nature immunocyte and necrosis cells as a DAMP, exerting pleiotropic biological effects by binding to RAGE, TLR and CXCL12, which lead to activation of CDC42, mitogen-activated protein kinases (MAPKs), c-IAP and NF-κB, thereby promoting angiogenesis, unlimited replicative potential, tissue invasion and metastasis. And it also involves in immune response by regulating immunocyte function as a immunocyte warning signal. Scholars have detected that HMGB1 is over expressed and released following chemotherapy and radiation therapy in cells of hematological malignancies, promoting malignant cell replication, decreasing therapeutic effect. Recently, endogenous HMGB1 has been implied to be an intrinsic modulator of autophagy and referenced to resistant to apoptosis in malignant hematosis cells. In contrast, through suppression of HMGB1 expression, tumor cell apoptosis and chemotherapeutic drug sensitivity were increased, which will be a new strategy for the treatment of hematological malignancies. In this article, the basic characteristics of HMGB1, including structure and biological features, and HMGB1 and tumors such as lymphoma, myeloproliferative neoplasms and acute myeloid leukemia are reviewed.
Animals ; HMGB1 Protein ; Hematologic Neoplasms ; therapy ; Humans

Endotoxemia ; metabolism ; pathology ; HMGB1 Protein ; Humans ; Liver ; metabolism ; pathology

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.
Cytokines ; immunology ; HMGB1 Protein ; immunology ; Humans ; Immunity, Cellular ; Inflammation ; immunology

High mobility group box 1 (HMGB1) is an endogenous danger signal molecule. In the postischemic brain, HMGB1 is massively released during NMDA-induced acute damage and triggers inflammatory processes. In a previous study, we demonstrated that intranasally delivered HMGB1 binding heptamer peptide (HBHP; HMSKPVQ) affords robust neuroprotective effects in the ischemic brain after middle cerebral artery occlusion (MCAO, 60 minutes). In the present study, we investigated HBHP-induced anti-inflammatory effects on microglia activation. In LPS-treated primary microglia culture, HMGB1 was rapidly released and accumulated in culture media. Furthermore, LPS-conditioned media collected from primary microglia cultures (LCM) activated naive microglia and markedly induced NO and proinflammatory cytokines. However, the suppression of HMGB1 by siRNA-HMGB1, HMGB1 A box, or anti-HMGB1 antibody significantly attenuated LCM-induced microglial activation, suggesting that HMGB1 plays a critical role in this process. A pull-down assay using biotin-labeled HBHP showed that HBHP binds directly to HMGB1 (more specifically to HMGB1 A box) in LCM. In addition, HBHP consistently inhibited LCM-induced microglial activation and suppressed the inductions of iNOS and proinflammatory cytokines. Together these results suggest that HBHP confers anti-inflammatory effects in activated microglia cultures by forming a complex with HMGB1.
Brain ; Culture Media ; Cytokines ; HMGB1 Protein ; Infarction, Middle Cerebral Artery ; Inflammation ; Microglia* ; Neuroprotective Agents

Eosinophils have been reported to modulate T cell responses. Previously, we reported that high-mobility group box 1 protein (HMGB1) played a key role in the pathogenesis of asthma. This study was conducted to test our hypothesis that eosinophils could modulate T cell responses via HMGB1 in the pathogenesis of asthma characterized by eosinophilic airway inflammation. We performed in vitro experiments using eosinophils, dendritic cells (DCs), and CD4+ T cells obtained from a murine model of asthma. The supernatant of the eosinophil culture was found to significantly increase the levels of interleukin (IL)-4 and IL-5 in the supernatant of CD4+ T cells co-cultured with DCs. HMGB1 levels increased in the supernatant of the eosinophil culture stimulated with IL-5. Anti-HMGB1 antibodies significantly attenuated increases of IL-4 and IL-5 levels in the supernatant of CD4+ T cells co-cultured with DCs that were induced by the supernatant of the eosinophil culture. In addition, anti-HMGB1 antibodies significantly attenuated the expressions of activation markers (CD44 and CD69) on CD4+ T cells. Our data suggest that eosinophils modulate CD4+ T cell responses via HMGB1 in the pathogenesis of asthma.
Antibodies ; Asthma* ; Dendritic Cells ; Eosinophils* ; HMGB1 Protein ; Inflammation ; Interleukin-4 ; Interleukin-5 ; Interleukins ; T-Lymphocytes

OBJECTIVETo investigate the expression level of high mobility group box-1 (HMGB1) in human colorectal cancer and its relation with different clinicopathological characteristics and prognosis of colorectal cancer patients.

METHODSImmunohistochemical method was used to detect the HMGB1 expression in tissue samples of 86 colorectal cancer patients and 32 normal colorectal tissue samples. Positive rates of HMGB1 expression were compared among different clinicopathological characteristics. Relation of HMGB1 expression with survival was analyzed.

RESULTSHMGB1 expression was mainly in colorectal cancer cell nucleus, with a few appearance of co-expression in nucleus and cytoplasm. Positive rate of HMGB1 expression in normal tissues was significantly lower than that in colorectal cancers [9.4% (3/32) vs. 66.3% (57/86), P=0.000], and it was much higher in large cancers, lower differentiation, invasion to outside serosa, advanced clinical stage and lymph node metastasis (all P<0.05), but was similar in terms of age and gender (P>0.05). Survival analysis showed that 3-year survival rate of patients with positive HMGB1 expression was significantly lower as compared to those with negative HMGB1 expression (56.1% vs. 85.7%, P=0.021), meanwhile it was significantly lower in patients with co-expression in nucleus and cytoplasm as compared to those with simple nuclear expression (41.4% vs. 75.0%, P=0.013).

CONCLUSIONSHMGB1 expression in colorectal cancer is high, and its positive rate increases with the low differentiation, invasion and metastasis. HMGB1 co-expression in nucleus and cytoplasm indicates poor prognosis of colorectal cancer patients.

Cell Nucleus ; Colorectal Neoplasms ; HMGB1 Protein ; Humans ; Lymphatic Metastasis ; Prognosis ; Survival Analysis ; Survival Rate