Interferon regulatory factor-1 mediates the release of high mobility group box-1 in endotoxemia in mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The extracellular release of the danger signal high mobility group box-1 (HMGB1) has been implicated in the pathogenesis and outcomes of sepsis. Understanding the mechanisms responsible for HMGB1 release can lead to the identification of targets that may inhibit this process. The transcription factor interferon regulatory factor-1 (IRF-1) is an important mediator of innate immune responses and has been shown to participate in mortality associated with endotoxemia; however, its role in mediating the release of HMGB1 in these settings is unknown.</p><p><b>METHODS</b>Male IRF-1 knockout (KO) and age matched C57BL/6 wild type (WT) mice were given intraperitoneal (IP) injections of lipopolysaccharide (LPS). In some experiments, 96 hours survival rates were observed. In other experiments, mice were sacrificed 12 hours after LPS administration and sera were harvested for future analysis. In in vitro study, RAW 264.7 murine monocyte/macrophage-like cells or primary peritoneal macrophage obtained from IRF-1 KO and WT mice were cultured for LPS mediated HMGB1 release analysis. And the mechanism for HMGB1 release was analyzed by immune-precipitation.</p><p><b>RESULTS</b>IRF-1 KO mice experienced less mortality, and released less systemic HMGB1 compared to their WT counterparts. Exogenous administration of recombinant HMGB1 to IRF-1 KO mice returned the mortality rate to that seen originally in IRF-1 WT mice. Using cultures of peritoneal macrophages or RAW264.7 cells, in vitro LPS stimulation induced the release of HMGB1 in an IRF-1 dependent manner. And the janus associated kinase (JAK)-IRF-1 signal pathway appeared to participate in the signaling mechanisms of LPS-induced HMGB1 release by mediating acetylation of HMGB1.</p><p><b>CONCLUSION</b>IRF-1 plays a role in LPS induced release of HMGB1 and therefore may serve as a novel target in sepsis.</p>

Immediately transcripted genes in various hepatic ischemia models / 대한외과학회지

PURPOSE: To elucidate the characteristic gene transcription profiles among various hepatic ischemia conditions, immediately transcribed genes and the degree of ischemic injury were compared among total ischemia (TI), intermittent clamping (IC), and ischemic preconditioning (IPC). METHODS: Sprague-Dawley rats were equally divided into control (C, sham-operated), TI (ischemia for 90 minutes), IC (ischemia for 15 minutes and reperfusion for 5 minutes, repeated six times), and IPC (ischemia for 15 minutes, reperfusion for 5 minutes, and ischemia again for 90 minutes) groups. A cDNA microarray analysis was performed using hepatic tissues obtained by partial hepatectomy after occluding hepatic inflow. RESULTS: The cDNA microarray revealed the following: interleukin (IL)-1beta expression was 2-fold greater in the TI group than in the C group. In the IC group, IL-1alpha/beta expression increased by 2.5-fold, and Na+/K+ ATPase beta1 expression decreased by 2.4-fold. In the IPC group, interferon regulatory factor-1, osteoprotegerin, and retinoblastoma-1 expression increased by approximately 2-fold compared to that in the C group, but the expression of Na+/K+ ATPase beta1 decreased 3-fold. CONCLUSION: The current findings revealed characteristic gene expression profiles under various ischemic conditions. However, additional studies are needed to clarify the mechanism of protection against IPC.

Expression of interferon regulatory factor-1 in the mouse cumulus-oocyte complex is negatively related with oocyte maturation / 대한생식의학회지

OBJECTIVE: We found previously that interferon regulatory factor (Irf)-1 is a germinal vesicle (GV)-selective gene that highly expressed in GV as compared to metaphase II oocytes. To our knowledge, the function of Irf-1 in oocytes has yet to be examined. The present study was conducted to determine the relationship between retinoic acid (RA) and RA-mediated expression of Irf-1 and the mouse oocyte maturation. METHODS: Immature cumulus-oocyte-complexes (COCs) were collected from 17-day-old female mice and cultured in vitro for 16 hours in the presence of varying concentrations of RA (0-10 microM). Rate of oocyte maturation and activation was measured. Gene expression was measured by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) and cytokine secretion in the medium was measured by Bio-Plex analysis. Apoptosis was analyzed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. RESULTS: The rates of oocyte maturation to metaphase II and oocyte activation increased significantly with RA treatment (10 nM-1 microM). With 100 nM RA treatment, lowest level of Irf-1 mRNA and cumulus cell's apoptosis was found. Among 23 cytokines measured by Bio-Plex system, the substantial changes in secretion of tumor necrosis factor-alpha, macrophage inflammatory protein-1beta, eotaxin and interleukin-12 (p40) from COCs in response to RA were detected. CONCLUSION: We concluded that the maturation of oocytes and Irf-1 expression are negatively correlated, and RA enhances the developmental competence of mouse immature oocytes in vitro by suppressing apoptosis of cumulus cells. Using a mouse model, results of the present study provide insights into improved culture conditions for in vitro oocyte maturation and relevant cytokine production and secretion in assisted reproductive technology.

Nerve growth factor increases sodium current via interferon regulatory factor-1 pathway in rat pheochromocytoma cells / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of nerve growth factor(NGF) and interferon regulatory factor-1(IRF-1) on sodium current change of sensory neuron in rat pheochromocytoma cells.@*METHODS@#Sensory neuron rat pheochromocytoma cells were stimulated by different concentrations of NGF(0-200 ng/mL), the IRF-1 mRNA levels were examined by real-time PCR, and the activation of IRF-1 was examined by Western blot. The sodium current change was recorded by patch clamp.@*RESULTS@#Low concentration of NGF improved the sodium current, which was concentration dependent. When exposed to high concentration of NGF, the expression of IRF-1 mRNA in PC-12 was improved. Low concentration of NGF resulted in IRF-1 intronuclear transporting, and the expression was not affected. Sodium current did not occur in PC-12 cells when IRF-1 was blocked.@*CONCLUSION@#NGF can improve the sodium current in PC-12 cells concentration-dependently, and the improvement is regulated by IRF-1.

Regulation mechanism for rig-g gene expression induced by all-trans retinoic acid / 中国实验血液学杂志

To investigate the molecular mechanisms of all-trans retinoic acid (ATRA)-induced rig-g gene expression and to better understand the signal transduction of ATRA during acute promyelocytic leukemia (APL) cell differentiation, the luciferase reporter assay, co-immunoprecipitation and chromatin immunoprecipitation were used to clarify the basic transcriptional factors, which directly initiated the expression of rig-g gene. The results showed that the expression of STAT2, IRF-9 and IRF-1 could be upregulated by ATRA with different kinetics in NB4 cells. IRF-9 was able to interact with STAT2 to form a complex, which could bind the rig-g gene promoter and trigger the rig-g expression. IRF-1 alone could also activate the reporter gene containing rig-g gene promoter, but C/EBPalpha could strongly inhibit this transcription activity of IRF-1. It is concluded that during ATRA-induced APL cell differentiation, IRF-1 is first upregulated by ATRA, and then IRF-1 increases the protein levels of IRF-9 and STAT2 with the downregulation of C/EBPalpha. The complex of IRF-9 and STAT2 is the primary transcriptional factor for rig-g gene induction. This study will be helpful for better understanding the signal transduction networks of ATRA during the course of APL cell differentiation.

Role of the interferon-stimulated response elements I/II in expression regulation of the retinoic acid induced gene G / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the regulatory role of interferon-stimulated response elements (ISREs) located on the retinoic acid-induced gene G (RIG-G) promoter in RIG-G expression.</p><p><b>METHODS</b>By using point mutation technique, the authors constructed the wide type and site mutant reporter gene plasmids according to the ISRE sequence on RIG-G promoter, and detected the functional activities by luciferase reporter assay.</p><p><b>RESULTS</b>Mutation in ISRE II alone had no obvious effect on the expression of the reporter gene, whereas mutation in ISRE I dramatically inhibited the transactivity of RIG-G promoter. Mutation in both ISRE I and ISRE II resulted in complete loss of its response to the transcription factors for the reporter gene.</p><p><b>CONCLUSION</b>Both ISRE I and ISRE II on the RIG-G promoter are the binding sites for the complex of transcription factors. They are required for RIG-G expression, and ISRE I has a preferential role over ISRE II.</p>

Mice-lacking LMP2, immuno-proteasome subunit, as an animal model of spontaneous uterine leiomyosarcoma

Uterine tumors are the most common type of gynecologic neoplasm. Uterine leiomyosarcoma (LMS) is rare, accounting for 2% to 5% of tumors of the uterine body. Uterine LMS develops more often in the muscle tissue layer of the uterine body than in the uterine cervix. The development of gynecologic tumors is often correlated with female hormone secretion; however, the development of uterine LMS is not substantially correlated with hormonal conditions, and the risk factors are not yet known. Radiographic evaluation combined with PET/CT can be useless in the diagnosis and surveillance of uterine LMS. Importantly, a diagnostic biomarker, which distinguishes malignant LMS and benign tumor leiomyoma (LMA) is yet to be established. Accordingly, it is necessary to analyze risk factors associated with uterine LMS in order to establish a method of treatment. LMP2-deficient mice spontaneously develop uterine LMS, with a disease prevalence of ∼40% by 14 months of age. It is therefore of interest whether human uterine LMS shows a loss of LMP2 expression. We found LMP2 expression is absent in human LMS, but present in human LMA. Therefore, defective LMP2 expression may be one of the risk factors for LMS. LMP2 is potentially a diagnostic biomarker for uterine LMS, and gene therapy with LMP2-encording DNA may be a new therapeutic approach.

Interferon regulatory factor-1 exerts inhibitory effect on neointimal formation after vascular injury / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effect of interferon regulatory factors (IRFs) on neointimal formation after vascular injury in the mouse, and its possible mechanism.</p><p><b>METHODS</b>Vascular injury was induced by polyethylene cuff placement around the left femoral artery of IRF-1-deficient mice and C57BL/6J mice. The mRNA expressions of IRF-1, IRF-2, angiotensin II type 2 (AT2) receptor, interleukin-1 beta converting enzyme (ICE), inducible nitric oxide synthase (iNOS) were detected by RT-PCR and immunohistochemical staining.</p><p><b>RESULTS</b>Neointimal formation after vascular injury was significantly greater in IRF-1-deficient mice than that in C57BL/6J mice (P<0.05). In contrast, TUNEL-positive nuclei to total nuclei in the neointima and media in vascular smooth muscle cell (VSMC) in the injured artery significantly attenuated in IRF-1-deficient mice compared to C57BL/6J mice (P<0.05). The expressions of AT2 receptor as well as pro-apoptotic genes such as ICE and iNOS in C57BL/6J mice were up-regulated in response to vascular injury, but this upregulation was attenuated in IRF-1-deficient mice.</p><p><b>CONCLUSIONS</b>Our results suggest that IRF-1 induces VSMC apoptosis and inhibits neointimal formation after vascular injury at least partly due to the upregulation of AT2 receptor, ICE and iNOS expressions. These results indicate that IRF-1 exerts an inhibitory effect on neointimal formation through the induction of apoptosis in VSMCs.</p>

Inmunopatogenia del lupus eritematoso sistémico, parte II: rol de los componentes del sistema inmune y de los autoanticuerpos / Pathogenesis of systemic lupus erythematosus, part II: role of immune system components and autoantibodies

El lupus eritematoso sistémico es una enfermedad autoinmune caracterizada por la producción de autoanticuerpos y una diversidad de manifestaciones clínicas. Pese a que su etiología es desconocida, factores genéticos y factores ambientales contribuyen a la pérdida de la tolerancia. Todos los componentes clave del sistema inmune participan en los mecanismos inmunopatogénicos que subyacen a la enfermedad. Esta revisión describe el rol de estos componentes.

Systemic lupus erythematosus is a systemic autoimmune disease characterized by the production of autoantibodies and a diversity of clinical manifestations. Although the etiology of systemic lupus erythematosus is unknown, both genetic and environmental factors contribute to the loss of self-tolerance. All key components of the immune systems are involved in the underlying mechanisms of the disease. This review describes the role of these components.

Association of loss of heterozygosity with cytogenetic abnormalities in acute myeloid leukemia and myelodysplastic syndrome

Deletions on chromosomes 5 and 7 are frequently seen in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). It is assumed that these deletions indicate loss of tumor suppressor genes on these chromosomes and until these tumor suppressor genes are identified, the functional consequences of these deletions and the molecular basis of these myeloid disorders cannot be completely understood. We evaluated loss of heterozygosity (LOH) in 44 patients (18 MDS and 26 AML, diagnosed according to WHO classification criteria) at diagnosis, using a four-microsatellite marker panel: an intragenic marker on the 7th intron of gene IRF-1 of the 5q31.1 region and three markers located inside the 7q31.1 region and correlated the LOH with karyotype abnormalities. The microsatellites chosen corresponded to chromosome regions frequently deleted in MDS/AML. The samples with Q (peak area) less than or equal to 0.50 were indicative of LOH. The percent of informative samples (i.e., heterozygous) for the intragenic microsatellite in gene IRF-1 and in loci D7S486, D7S515 and D7S522 were 66.6, 73.7, 75.5, and 48.8 percent, respectively. Cytogenetic abnormalities by G-banding were found in 36 percent (16/44) of the patients (2 of 18 MDS and 14 of 26 AML patients). We found a significantly positive association of the occurrence of LOH with abnormal karyotype (P < 0.05; chi-square test) and there were cases with LOH but the karyotype was normal (by G-banding). These data indicate that LOH in different microsatellite markers is possibly an event previous to chromosomal abnormalities in these myeloid neoplasias.

Establishment of a nude mouse model of nasopharyngeal carcinoma lymph node metastasis and screening of the metastasis-related signature genes / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a nude mouse model of nasopharyngeal carcinoma (NPC) lymph node metastasis and screen the signature genes associated with the metastasis.</p><p><b>METHODS</b>The NPC 5-8F-EGFP cells were inoculated into nude mice, from which a 5-8F-LN cell line with lymph node metastasis potential was obtained. The lymphatic metastasis-related signature genes of breast cancer and head and neck squamous cell carcinoma were screened by data mining method.</p><p><b>RESULTS</b>The NPC cell lines 5-8F and 6-10B showed 307 differentially expressed genes by microarray analysis, from which 20 overlapping genes were identified, and 3 overexpressed genes were found with probable metastasis potential, namely the ADM, IRF1, and CAV1 genes. Quantitative RT-PCR validated the data mining results in the 5-8F-EGFP, 6-10B-EGFP, NP69, and 5-8F-LN cell lines. The 3 NPC cell lines 5-8F-EGFP, 6-10B-EGFP and 5-8F-LN showed significantly higher expressions of IRF1 than NP69 cells (P=0.008, 0.022, and 0.006, respectively. The expression level of CAV1 in 5-8F-EGFP cells was significantly higher than that in 6-10B-EGFP cells (P=0.014), but ADM expression showed no significant difference between the 4 cell lines.</p><p><b>CONCLUSIONS</b>IRF1 may play an important role in the progression of NPC. The overexpression of CAV1 in 5-8F-EGFP cells can be associated with the high metastatic potential of the cells.</p>

Study on mechanisms of the expression regulation of interferon-induced gene RIG-G / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the molecular mechanisms of the expression regulation of retinoic acidinduced gene G (RIG-G) by interferon alpha (IFNalpha).</p><p><b>METHODS</b>RIG-G promoter region was analyzed by bioinformatics. The functional activities of RIG-G promoter with or without IFNalpha were detected by luciferase reporter assay and electrophoretic mobility shift assay (EMSA).</p><p><b>RESULTS</b>RIG-G promoter region contained two well-conserved IFN-stimulated response elements (ISREs). Both ISRE I and ISRE II showed their effective binding abilities with signal transducer and activator of transcription 1 (STAT1). In HT1080 cells, in contrast with the empty plasmid pXP2, pXP2-A reporter construct containing intact ISRE I and ISRE II showed a significant higher baseline expression (1741.2 +/- 517.5) which could be further enhanced up to three-four folds by IFNalpha (5338.7 +/- 1226.9, P < 0.05). However, the luciferase activity of pXP2-A as well as its IFNalpha inducibility could be abrogated in STAT1-deficient U3A cells (from 1741.2 +/- 517.5 to 406.1 +/- 103.2, P < 0.05), indicating that the STAT1 protein was a prerequisite for the activities of ISRE I and ISRE II.</p><p><b>CONCLUSION</b>ISREs present in RIG-G promoter region are molecular basis of IFNalpha induced RIG-G expression. RIG-G is a target gene directly regulated by STAT1 protein and should play a key role in IFNalpha signaling pathways.</p>

Growth Suppression of Ovarian Cancer Cells by Interferon-gama / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Growth regulation of cancer cells very frequently involves tumor suppressor gene p53, Rb and cell cycle regulator, however the molecular biologic mechanisms of growth regulation in ovarian carcinoma cells are not fully defined. To assess the mechanism of growth suppression, we treated IFN-gama in ovarian carcinoma cells. MATERIALS AND METHODS: Growth suppression by treatment of IFN-gama was determined by cell proliferation assay in ovarian carcinoma cell lines. Apoptosis was determined by DNA fragmentation assay and electron microscopy. Molecular mechanism of the apoptosis in ovarian carcinoma cell by IFN-gama was further analyzed by the western blot. RESULTS: We found that IFN-gama had remarkable growth- suppressive effects in PA-1 and A2774 ovarian carcinoma cells in a time-dependent manner. Apoptosis was observed in PA-1 and A2774 cell following treatment of IFN- gama by DNA fragmentation assay and EM. The expression of IRF-1 protein from A2774 and PA-1 cell extracts was elevated by increasing the concentration of IFN-gama. IFN-gama caused an increased expression of the important apoptosis-related gene, ICE (interleukin-1beta-converting enzyme) protein in A2774 and PA-1. CONCLUSION: The coordinate induction of IRF-1 and ICE by IFN-gama in ovarian carcinoma cells suggests a functional relationship between these proteins in programmed cell death. The significance of this study is the molecular biologic background of IFN-gama considered as an alternative treatment trial of ovarian cancers.

Novel Molecular Biologic Mechanism of Growth Suppressive Regulation by Retinoid / Interferon in Cervical Cancer Cells / 대한산부인과학회잡지

OBJECTIVE: Retinoic acids (RAs) and interferons (IFNs) have been implicated in the growth regulation of cervical cancer cells, which was suggested by clinical trials and in vitro experiments. However, the molecular mechanisms of growth regulation are not fully defined, The purpose of this study is to assess the effect of RA and/or IFN on human cervical carcinoma cells in vitro and to analyze their action mechanisms in HPV-positive cervical carcinoma cells by molecular biologic studies. METHODS: HPV-positive (CaSki, HeLa), HPV-negative (C33A, HT-3), and non-cervical cancer Cos-1 cell lines were treated with RA and/ar IFN. Their effects on cell growth were evaluated by the cell pmliferation assay and the following BrdU DNA incorporation assay. The molecular mechanism was further investigated by a series of immunoblottings and transient cotransfection assays, which were conducted in HeLa cells and C33A cells using the CAT reporter gene assay. To observe the down regulation of HPV E6/E7 gene expression by RA/IFN, reverse transcription-polymerase chain reaction (RT-PCR) was perforned. RESULTS: The powth of RA-treated cells was less suppressed than that of IFN-treated cells. Combined treatment of RA and IFN leads to additive effect on the growth suppression of HeLa and CaSki cells. The proliferation activity was most severely reduced in Hela cells by treatment of both all-trans-RA (AtRA) and IFN-r. Combined treatment of AtRA/IFN-r causes a great increase in the level of interferon regulatory factor-1 (IRF-1) protein in HeLa cells, whereas no induction of IRF-1 was observed in C33A cells. The CAT gene expression for IRF-1 was greatly induced by IFN-r in HeLa cells. Immunoblotting assays shows the concurrent induction of p21 CDK inhibitor and dephosphorylation of Rb protein in HeLa cells. In RT-PCR, an individual treatment of either RA or IFN reduced HPV E6/E7 mRNA levels and significantly cooperative when both RA and IFN were treated. By deaeasing E6 levels, the p53 level was increased in HeLs cells treated with RA and/or IFN. Transient cotransfection of IRF-1 and p53 as the transcription factors leads to the cooperative activation of a common p21 promoter to regulate the cell cycle. CONCLUSION: RA/IFN suppressed the growth of HPV-positive cervical cancer cells. When they were both treated, additive suppressive effects were observed in cellular proliferation as well as DNA synthesis. The growth suppressive effect is likely to be related to the increased expression of IRF-1 and p21 (antitumoral effect; p53-independent). The down regulation of HPV E6 gene suppression may account for the resultant increase of p53 levels (antiviral effect; p53-dependent). Both induced IRF-1 and p53 cooperatively augument tbe suppession of p21 CDK inhibitor, which results in dephosphorylation of pRb. Although clinical effects are likely complex and may include interactions of in vitro growth inhibitory effects with immunomodulatory and antiangiogeaetic effect, tbese results suggest the optimal clinical role for the combination of RA/IFN in the treatment of cervical canccers.

IRF-1 and IRF-2 as regulators of the interferon system and cell growth.

Interferons (IFNs) are families of cytokines which have been discovered and extensively characterized in the context of host defense against viral infections. We have discovered two structurally related transcription factors, Interferon regulatory factor-1 (IRF-1) and IRF-2. These two factors, however, function not only as regulators of the IFN system, but are also key transcription factors in the regulation of cell cycle and apoptosis. These studies uncover a complex gene transcription network, by which the fate of cellular responses are determined depending on how the IRF transcription factors function in conjunction with other factors, and on the promoters of distinct genes under different conditions of the cells.