Paul J Hertzog

Publications of Paul J Hertzog

• The Ets transcription factor ELF5 functions as a tumor suppressor in the kidney.

  Authors: Erika J Lapinskas, Suzanne Svobodova, Ian D Davis, Jonathan Cebon, Paul J Hertzog, Melanie A Pritchard

  Twin research and human genetics : the official journal of the International Society for Twin Studies. 08/2011; 14(4):316-22.

  Renal cell carcinoma is an important clinical disease with poorly understood etiology. ELF5 is an epithelial-specific member of the Ets family of transcription factors, characterized by the 80 aminoRenal cell carcinoma is an important clinical disease with poorly understood etiology. ELF5 is an epithelial-specific member of the Ets family of transcription factors, characterized by the 80 amino acid Ets domain that binds the purine-rich GGAA/T Ets motif found in the promoter regions of a variety of genes. Since ELF5 is highly expressed in kidney and has been postulated to function as a tumor suppressor, at least in the context of the breast, we investigated its role in kidney cancer. In renal cell carcinoma ELF5 expression was consistently decreased in tumor samples versus normal. ELF5 mRNA was decreased in 94% of lesions tested and ELF5 protein was undetectable in 40/40 kidney-derived carcinomas. Re-expression of the ELF5 gene in 786-O renal carcinoma cells suppressed their tumorigenic capacity in vitro and in vivo. This work is the first to suggest that ELF5 has tumor suppressor activity in the kidney.

• Suppressor of cytokine signaling (SOCS) 1 inhibits type I interferon (IFN) signaling via the interferon alpha receptor (IFNAR1)-associated tyrosine kinase Tyk2.

  Authors: Rebecca A R Piganis, Nicole A De Weerd, Jodee A Gould, Christian W Schindler, Ashley Mansell, Sandra E Nicholson, Paul J Hertzog

  The Journal of biological chemistry. 07/2011; 286(39):33811-8.

  Type I IFNs are critical players in host innate and adaptive immunity. IFN signaling is tightly controlled to ensure appropriate immune responses as imbalance could result in uncontrolledType I IFNs are critical players in host innate and adaptive immunity. IFN signaling is tightly controlled to ensure appropriate immune responses as imbalance could result in uncontrolled inflammation or inadequate responses to infection. It is therefore important to understand how type I IFN signaling is regulated. Here we have investigated the mechanism by which suppressor of cytokine signaling 1 (SOCS1) inhibits type I IFN signaling. We have found that SOCS1 inhibits type I IFN signaling not via a direct interaction with the IFN α receptor 1 (IFNAR1) receptor component but through an interaction with the IFNAR1-associated kinase Tyk2. We have characterized the residues/regions involved in the interaction between SOCS1 and Tyk2 and found that SOCS1 associates via its SH2 domain with conserved phosphotyrosines 1054 and 1055 of Tyk2. The kinase inhibitory region of SOCS1 is also essential for its interaction with Tyk2 and inhibition of IFN signaling. We also found that Tyk2 is preferentially Lys-63 polyubiquitinated and that this activation reaction is inhibited by SOCS1. The consequent effect of SOCS1 inhibition of Tyk2 not only results in a reduced IFN response because of inhibition of Tyk2 kinase-mediated STAT signaling but also negatively impacts IFNAR1 surface expression, which is stabilized by Tyk2.

• Type I-IFNs control GVHD and GVL responses after transplantation.

  Authors: Renee J Robb, Ellen Kreijveld, Rachel D Kuns, Yana A Wilson, Stuart D Olver, Alistair L J Don, Neil C Raffelt, Nicole A De Weerd, Katie E Lineburg, Antiopi Varelias, Kate A Markey, Motoko Koyama, Andrew D Clouston, Paul J Hertzog, Kelli P A Macdonald, Geoffrey R Hill

  Blood. 06/2011; 118(12):3399-409.

  Although the effects of type II-IFN (IFN-γ) on GVHD and leukemia relapse are well studied, the effects of type I-interferon (type I-IFN, IFN-α/β) remain unclear. We investigated this using type I-IFNAlthough the effects of type II-IFN (IFN-γ) on GVHD and leukemia relapse are well studied, the effects of type I-interferon (type I-IFN, IFN-α/β) remain unclear. We investigated this using type I-IFN receptor-deficient mice and exogenous IFN-α administration in established models of GVHD and GVL. Type I-IFN signaling in host tissue prevented severe colon-targeted GVHD in CD4-dependent models of GVHD directed toward either major histocompatibility antigens or multiple minor histocompatibility antigens. This protection was the result of suppression of donor CD4(+) T-cell proliferation and differentiation. Studies in chimeric recipients demonstrated this was due to type I-IFN signaling in hematopoietic tissue. Consistent with this finding, administration of IFN-α during conditioning inhibited donor CD4(+) proliferation and differentiation. In contrast, CD8-dependent GVHD and GVL effects were enhanced when type I-IFN signaling was intact in the host or donor, respectively. This finding reflected the ability of type I-IFN to both sensitize host target tissue/leukemia to cell-mediated cytotoxicity and augment donor CTL function. These data confirm that type I-IFN plays an important role in defining the balance of GVHD and GVL responses and suggests that administration of the cytokine after BM transplantation could be studied prospectively in patients at high risk of relapse.

• LPS hypersensitivity of gp130 mutant mice is independent of elevated haemopoietic TLR4 signaling.

  Authors: Claire J Greenhill, Jodee Gould, Matthias Ernst, Paul J Hertzog, Ashley Mansell, Brendan J Jenkins

  Immunology and cell biology. 06/2011;

  Among the many inflammatory mediators induced by the prototypical inflammatory stimulus lipopolysaccharide (LPS), which signals via Toll-like receptor (TLR)-4, interleukin (IL)-6 has recently beenAmong the many inflammatory mediators induced by the prototypical inflammatory stimulus lipopolysaccharide (LPS), which signals via Toll-like receptor (TLR)-4, interleukin (IL)-6 has recently been shown to feedback and augment TLR4 signaling when overproduced in LPS hypersensitive gp130(F/F) mice. This regulation by IL-6 in gp130(F/F) mice requires hyperactivation of the latent transcription factor signal transducer and activator of transcription (STAT) 3 via the IL-6 signaling receptor subunit gp130. However, the identity of LPS/TLR4-responsive inflammatory signaling pathways and gene networks, which are modulated by IL-6 (via gp130/STAT3), and the extent to which the tissue and cellular context of this regulation contributes to LPS-induced endotoxic shock in gp130(F/F) mice, are unknown. We report here that in LPS-treated macrophages from gp130(F/F) mice, gp130 hyperactivation upregulated the LPS-induced expression of inflammatory mediators downstream of Janus kinase (JAK)/STAT, nuclear factor κ-light-chain-enhancer of activated B cells, interferon regulatory factor and c-Jun N-terminal kinase/p38 mitogen-activated protein kinase pathways. Notably, however, LPS administration to bone marrow chimeras indicated that heightened LPS/TLR4 signaling in haemopoietic-derived gp130(F/F) immune cells is dispensable for the hypersensitivity of gp130(F/F) mice to LPS-induced endotoxemia. To understand the molecular consequences of gp130 hyperactivity in non-haemopoietic tissue on LPS-induced systemic inflammation, global gene expression profiling of livers from LPS-treated gp130(F/F) mice was performed and identified 264 hepatic LPS-responsive genes, which are differentially regulated by hyperactive gp130 signaling. Collectively, the substantial transcriptional reprogramming of LPS-responsive genes in gp130(F/F) mice emphasizes non-haemopoietic gp130 signaling as a key regulator of systemic inflammatory responses during LPS-induced endotoxemia.Immunology and Cell Biology advance online publication, 14 June 2011; doi:10.1038/icb.2011.56.

• Analysis of microRNA turnover in mammalian cells following Dicer1 ablation.

  Authors: Michael P Gantier, Claire E McCoy, Irina Rusinova, Damien Saulep, Die Wang, Dakang Xu, Aaron T Irving, Mark A Behlke, Paul J Hertzog, Fabienne Mackay, Bryan R G Williams

  Nucleic acids research. 03/2011; 39(13):5692-703.

  Although microRNAs (miRNAs) are key regulators of gene expression, little is known of their overall persistence in the cell following processing. Characterization of such persistence is key to theAlthough microRNAs (miRNAs) are key regulators of gene expression, little is known of their overall persistence in the cell following processing. Characterization of such persistence is key to the full appreciation of their regulatory roles. Accordingly, we measured miRNA decay rates in mouse embryonic fibroblasts following loss of Dicer1 enzymatic activity. The results confirm the inherent stability of miRNAs, the intracellular levels of which were mostly affected by cell division. Using the decay rates of a panel of six miRNAs representative of the global trend of miRNA decay, we establish a mathematical model of miRNA turnover and determine an average miRNA half-life of 119 h (i.e. ∼5 days). In addition, we demonstrate that select miRNAs turnover more rapidly than others. This study constitutes, to our knowledge, the first in-depth characterization of miRNA decay in mammalian cells. Our findings indicate that miRNAs are up to 10× more stable than messenger RNA and support the existence of novel mechanism(s) controlling selective miRNA cellular concentration and function.

• Sculpting the immune response to infection.

  Authors: Paul J Hertzog, Ashley Mansell, Ian R van Driel, Elizabeth L Hartland

  Nature immunology. 01/2011; 12(7):579-82.

• IL-6 trans-signaling modulates TLR4-dependent inflammatory responses via STAT3.

  Authors: Claire J Greenhill, Stefan Rose-John, Rami Lissilaa, Walter Ferlin, Matthias Ernst, Paul J Hertzog, Ashley Mansell, Brendan J Jenkins

  Journal of immunology (Baltimore, Md. : 1950). 01/2011; 186(2):1199-208.

  Innate immune responses triggered by the prototypical inflammatory stimulus LPS are mediated by TLR4 and involve the coordinated production of a multitude of inflammatory mediators, especially IL-6,Innate immune responses triggered by the prototypical inflammatory stimulus LPS are mediated by TLR4 and involve the coordinated production of a multitude of inflammatory mediators, especially IL-6, which signals via the shared IL-6 cytokine family receptor subunit gp130. However, the exact role of IL-6, which can elicit either proinflammatory or anti-inflammatory responses, in the pathogenesis of TLR4-driven inflammatory disorders, as well as the identity of signaling pathways activated by IL-6 in a proinflammatory state, remain unclear. To define the contribution of gp130 signaling events to TLR4-driven inflammatory responses, we combined genetic and therapeutic approaches based on a series of gp130(F/F) knock-in mutant mice displaying hyperactivated IL-6-dependent JAK/STAT signaling in an experimental model of LPS/TLR4-mediated septic shock. The gp130(F/F) mice were markedly hypersensitive to LPS, which was associated with the specific upregulated production of IL-6, but not TNF-α. In gp130(F/F) mice, either genetic ablation of IL-6, Ab-mediated inhibition of IL-6R signaling or therapeutic blockade of IL-6 trans-signaling completely protected mice from LPS hypersensitivity. Furthermore, genetic reduction of STAT3 activity in gp130(F/F):Stat3(+/-) mice alleviated LPS hypersensitivity and reduced LPS-induced IL-6 production. Additional genetic approaches demonstrated that the TLR4/Mal pathway contributed to LPS hypersensitivity and increased IL-6 production in gp130(F/F) mice. Collectively, these data demonstrate for the first time, to our knowledge, that IL-6 trans-signaling via STAT3 is a critical modulator of LPS-driven proinflammatory responses through cross-talk regulation of the TLR4/Mal signaling pathway, and potentially implicate cross-talk between JAK/STAT and TLR pathways as a broader mechanism that regulates the severity of the host inflammatory response.

• Macrophage activation and differentiation signals regulate schlafen-4 gene expression: evidence for Schlafen-4 as a modulator of myelopoiesis.

  Authors: Wendy J van Zuylen, Valerie Garceau, Adi Idris, Kate Schroder, Katharine M Irvine, Jane E Lattin, Dmitry A Ovchinnikov, Andrew C Perkins, Andrew D Cook, John A Hamilton, Paul J Hertzog, Katryn J Stacey, Stuart Kellie, David A Hume, Matthew J Sweet

  PloS one. 01/2011; 6(1):e15723.

  The ten mouse and six human members of the Schlafen (Slfn) gene family all contain an AAA domain. Little is known of their function, but previous studies suggest roles in immune cell development. InThe ten mouse and six human members of the Schlafen (Slfn) gene family all contain an AAA domain. Little is known of their function, but previous studies suggest roles in immune cell development. In this report, we assessed Slfn regulation and function in macrophages, which are key cellular regulators of innate immunity. Multiple members of the Slfn family were up-regulated in mouse bone marrow-derived macrophages (BMM) by the Toll-like Receptor (TLR)4 agonist lipopolysaccharide (LPS), the TLR3 agonist Poly(I∶C), and in disease-affected joints in the collagen-induced model of rheumatoid arthritis. Of these, the most inducible was Slfn4. TLR agonists that signal exclusively through the MyD88 adaptor protein had more modest effects on Slfn4 mRNA levels, thus implicating MyD88-independent signalling and autocrine interferon (IFN)-β in inducible expression. This was supported by the substantial reduction in basal and LPS-induced Slfn4 mRNA expression in IFNAR-1⁻/⁻ BMM. LPS causes growth arrest in macrophages, and other Slfn family genes have been implicated in growth control. Slfn4 mRNA levels were repressed during macrophage colony-stimulating factor (CSF-1)-mediated differentiation of bone marrow progenitors into BMM. To determine the role of Slfn4 in vivo, we over-expressed the gene specifically in macrophages in mice using a csf1r promoter-driven binary expression system. Transgenic over-expression of Slfn4 in myeloid cells did not alter macrophage colony formation or proliferation in vitro. Monocyte numbers, as well as inflammatory macrophages recruited to the peritoneal cavity, were reduced in transgenic mice that specifically over-expressed Slfn4, while macrophage numbers and hematopoietic activity were increased in the livers and spleens. Slfn4 mRNA levels were up-regulated during macrophage activation but down-regulated during differentiation. Constitutive Slfn4 expression in the myeloid lineage in vivo perturbs myelopoiesis. We hypothesise that the down-regulation of Slfn4 gene expression during macrophage differentiation is a necessary step in development of this lineage.

• Cutting edge: pulmonary Legionella pneumophila is controlled by plasmacytoid dendritic cells but not type I IFN.

  Authors: Desmond K Y Ang, Clare V L Oates, Ralf Schuelein, Michelle Kelly, Fiona M Sansom, Dorothée Bourges, Louis Boon, Paul J Hertzog, Elizabeth L Hartland, Ian R van Driel

  Journal of immunology (Baltimore, Md. : 1950). 05/2010; 184(10):5429-33.

  Plasmacytoid dendritic cells (pDCs) are well known as the major cell type that secretes type I IFN in response to viral infections. Their role in combating other classes of infectious organisms,Plasmacytoid dendritic cells (pDCs) are well known as the major cell type that secretes type I IFN in response to viral infections. Their role in combating other classes of infectious organisms, including bacteria, and their mechanisms of action are poorly understood. We have found that pDCs play a significant role in the acute response to the intracellular bacterial pathogen Legionella pneumophila. pDCs were rapidly recruited to the lungs of L. pneumophila-infected mice, and depletion of pDCs resulted in increased bacterial load. The ability of pDCs to combat infection did not require type I IFN. This study points to an unappreciated role for pDCs in combating bacterial infections and indicates a novel mechanism of action for this cell type.

• Functional crosstalk between type I and II interferon through the regulated expression of STAT1.

  Authors: Daniel J Gough, Nicole L Messina, Linda Hii, Jodee A Gould, Kanaga Sabapathy, Ashley P S Robertson, Joseph A Trapani, David E Levy, Paul J Hertzog, Christopher J P Clarke, Ricky W Johnstone

  PLoS biology. 01/2010; 8(4):e1000361.

  Autocrine priming of cells by small quantities of constitutively produced type I interferon (IFN) is a well-known phenomenon. In the absence of type I IFN priming, cells display attenuated responsesAutocrine priming of cells by small quantities of constitutively produced type I interferon (IFN) is a well-known phenomenon. In the absence of type I IFN priming, cells display attenuated responses to other cytokines, such as anti-viral protection in response to IFNgamma. This phenomenon was proposed to be because IFNalpha/beta receptor1 (IFNAR1) is a component of the IFNgamma receptor (IFNGR), but our new data are more consistent with a previously proposed model indicating that regulated expression of STAT1 may also play a critical role in the priming process. Initially, we noticed that DNA binding activity of STAT1 was attenuated in c-Jun(-/-) fibroblasts because they expressed lower levels of STAT1 than wild-type cells. However, expression of STAT1 was rescued by culturing c-Jun(-/-) fibroblasts in media conditioned by wild-type fibroblasts suggesting they secreted a STAT1-inducing factor. The STAT1-inducing factor in fibroblast-conditioned media was IFNbeta, as it was inhibited by antibodies to IFNAR1, or when IFNbeta expression was knocked down in wild-type cells. IFNAR1(-/-) fibroblasts, which cannot respond to this priming, also expressed reduced levels of STAT1, which correlated with their poor responses to IFNgamma. The lack of priming in IFNAR1(-/-) fibroblasts was compensated by over-expression of STAT1, which rescued molecular responses to IFNgamma and restored the ability of IFNgamma to induce protective anti-viral immunity. This study provides a comprehensive description of the molecular events involved in priming by type I IFN. Adding to the previous working model that proposed an interaction between type I and II IFN receptors, our work and that of others demonstrates that type I IFN primes IFNgamma-mediated immune responses by regulating expression of STAT1. This may also explain how type I IFN can additionally prime cells to respond to a range of other cytokines that use STAT1 (e.g., IL-6, M-CSF, IL-10) and suggests a potential mechanism for the changing levels of STAT1 expression observed during viral infection.

• Transcript profiling of Elf5+/- mammary glands during pregnancy identifies novel targets of Elf5.

  Authors: Renee L Rogers, Isabelle Van Seuningen, Jodee Gould, Paul J Hertzog, Matthew J Naylor, Melanie A Pritchard

  PloS one. 01/2010; 5(10):e13150.

  Elf5, an epithelial specific Ets transcription factor, plays a crucial role in the pregnancy-associated development of the mouse mammary gland. Elf5(-/-) embryos do not survive, however the Elf5(+/-)Elf5, an epithelial specific Ets transcription factor, plays a crucial role in the pregnancy-associated development of the mouse mammary gland. Elf5(-/-) embryos do not survive, however the Elf5(+/-) mammary gland displays a severe pregnancy-associated developmental defect. While it is known that Elf5 is crucial for correct mammary development and lactation, the molecular mechanisms employed by Elf5 to exert its effects on the mammary gland are largely unknown. Transcript profiling was used to investigate the transcriptional changes that occur as a result of Elf5 haploinsufficiency in the Elf5(+/-) mouse model. We show that the development of the mouse Elf5(+/-) mammary gland is delayed at a transcriptional and morphological level, due to the delayed increase in Elf5 protein in these glands. We also identify a number of potential Elf5 target genes, including Mucin 4, whose expression, is directly regulated by the binding of Elf5 to an Ets binding site within its promoter. We identify novel transcriptional targets of Elf5 and show that Muc4 is a direct target of Elf5, further elucidating the mechanisms through which Elf5 regulates proliferation and differentiation in the mammary gland.

• Bacterial membrane vesicles deliver peptidoglycan to NOD1 in epithelial cells.

  Authors: Maria Kaparakis, Lynne Turnbull, Leticia Ccarneiro, Stephen Firth, Harold A Coleman, Helena C Parkington, Lionel Le Bourhis, Abdulgader Karrar, Jérôme Viala, Johnson Mak, Melanie L Hutton, John K Davies, Peter J Crack, Paul J Hertzog, Dana J Philpott, Stephen E Girardin, Cynthia B Whitchurch, Richard L Ferrero

  Cellular microbiology. 11/2009;

  Summary Gram negative bacterial peptidoglycan is specifically recognized by the host intracellular sensor NOD1, resulting in the generation of innate immune responses. Although epithelial cells areSummary Gram negative bacterial peptidoglycan is specifically recognized by the host intracellular sensor NOD1, resulting in the generation of innate immune responses. Although epithelial cells are normally refractory to external stimulation with peptidoglycan, these cells have been shown to respond in a NOD1 dependent manner to Gram negative pathogens that can either invade or secrete factors into host cells. In the present work, we report that Gram negative bacteria can deliver peptidoglycan to cytosolic NOD1 in host cells via a novel mechanism involving outer membrane vesicles (OMVs). We purified OMVs from the Gram negative mucosal pathogens: Helicobacter pylori, Pseudomonasaeruginosa and Neisseria gonorrhoea and demonstrated that these peptidoglycan containing OMVs upregulated NF-kappaB and NOD1 dependent responses in vitro. These OMVs entered epithelial cells through lipid rafts thereby inducing NOD1 dependent responses in vitro. Moreover, OMVs delivered intragastrically to mice induced innate and adaptive immune responses via a NOD1 dependent but TLR independent mechanism. Collectively, our findings identify OMVs as a generalized mechanism whereby Gram-negative bacteria deliver peptidoglycan to cytosolic NOD1. We propose that OMVs released by bacteria in vivo may promote inflammation and pathology in infected hosts.

• MyD88 adapter-like (mal)/TIRAP interaction with TRAF6 is critical for TLR2- and TLR4-mediated NF-{kappa}B proinflammatory responses.

  Authors: Brett Verstak, Kamalpreet Nagpal, Stephen P. Bottomley, Douglas T Golenbock, Paul J Hertzog, Ashley Mansell

  The Journal of biological chemistry. 08/2009;

  TIR-containing adapters are critical in orchestrating the different signal transduction pathways following Toll-like receptor (TLR) activation. MyD88 adapter-like (Mal), also termed TIRAP, isTIR-containing adapters are critical in orchestrating the different signal transduction pathways following Toll-like receptor (TLR) activation. MyD88 adapter-like (Mal), also termed TIRAP, is involved in bridging MyD88 to the receptor complex for TLR-2 and TLR4 signaling in response to bacterial infection. We have previously reported an interaction between Mal and TNF receptor associated factor (TRAF)-6 via a TRAF6-binding motif, the disruption of which inhibited TLR-mediated NF-kappaB-luciferase reporter activity. Given the recent report of intracellular TRIF-related adapter molecule (TRAM) localization promoting sequential signaling in TLR4 responses, we further characterized Mal interaction with TRAF6, the cellular localization and the outcomes of disrupting this association on TLR inflammatory responses. We found that Mal and TRAF6 directly interact in response to TLR2 and TLR4 stimulation, although membrane localization is not necessary to facilitate interaction. Critically, reconstitution of murine Mal-deficient macrophages with MalE190A, containing a mutation within the TRAF6-binding motif, fails to reconstitute the proinflammatory response to TLR2 and TLR4 ligands compared to wild type Mal. Furthermore, Mal interaction with TRAF6 mediates Ser phosphorylation of the p65 subunit of NF-kappaB and thus controls transcriptional activation, but not nuclear translocation of NF-kappaB. This study characterizes the novel role for Mal in facilitating the direct recruitment of TRAF6 to the plasma membrane, which is necessary for TLR2- and TLR4-induced transactivation of NF-kappaB and regulation of the subsequent pro-inflammatory response.

• GM-CSF- and M-CSF-dependent macrophage phenotypes display differential dependence on Type I interferon signaling.

  Authors: Andrew J Fleetwood, Hang Dinh, Andrew D Cook, Paul J Hertzog, John A Hamilton

  Journal of leukocyte biology. 05/2009;

  M-CSF and GM-CSF are mediators involved in regulating the numbers and function of macrophage lineage populations and have been shown to contribute to macrophage heterogeneity. Type I IFN is anM-CSF and GM-CSF are mediators involved in regulating the numbers and function of macrophage lineage populations and have been shown to contribute to macrophage heterogeneity. Type I IFN is an important mediator produced by macrophages and can have profound regulatory effects on their properties. In this study, we compared bone marrow-derived macrophages (BMM) and GM-CSF-induced BMM (GM-BMM) from wild-type and IFNAR1(-/-) mice to assess the contribution of endogenous type I IFN to the phenotypic differences between BMM and GM-BMM. BMM were capable of higher constitutive IFN-beta production, which contributed significantly to their basal transcriptome. Microarray analysis found that of the endogenous type I IFN-regulated genes specific to either BMM or GM-BMM, 488 of these gene alterations were unique to BMM, while only 50 were unique to GM-BMM. Moreover, BMM displayed enhanced basal mRNA levels, relative to GM-BMM, of a number of genes identified as being dependent on type I IFN signaling, including Stat1, Stat2, Irf7, Ccl5, Ccl12, and Cxcl10. As a result of prior type I IFN "priming," upon LPS stimulation BMM displayed increased activation of the MyD88-independent IRF-3/STAT1 pathways compared with GM-BMM, which correlated with the distinct cytokine/chemokine profiles of the two macrophage subsets. Furthermore, the autocrine type I IFN signaling loop regulated the production of the M1 and M2 signature cytokines, IL-12p70 and IL-10. Collectively, these findings demonstrate that constitutive and LPS-induced type I IFN play significant roles in regulating the differences in phenotype and function between BMM and GM-BMM.

• INTERFEROME: the database of interferon regulated genes.

  Authors: Shamith A Samarajiwa, Sam Forster, Katie Auchettl, Paul J Hertzog

  Nucleic acids research. 12/2008;

  INTERFEROME is an open access database of types I, II and III Interferon regulated genes (http://www.interferome.org) collected from analysing expression data sets of cells treated with IFNs. ThisINTERFEROME is an open access database of types I, II and III Interferon regulated genes (http://www.interferome.org) collected from analysing expression data sets of cells treated with IFNs. This database of interferon regulated genes integrates information from high-throughput experiments with annotation, ontology, orthologue sequences from 37 species, tissue expression patterns and gene regulatory information to enable a detailed investigation of the molecular mechanisms underlying IFN biology. INTERFEROME fulfils a need in infection, immunity, development and cancer research by providing computational tools to assist in identifying interferon signatures in gene lists generated by high-throughput expression technologies, and their potential molecular and biological consequences.

• ABSENCE OF GLUTATHIONE PEROXIDASE-1 (GPX1) EXACERBATES CEREBRAL ISCHEMIA-REPERFUSION INJURY BY REDUCING POST-ISCHEMIC MICROVASCULAR PERFUSION.

  Authors: Connie H Y Wong, Steven Bozinovski, Paul J Hertzog, Michael J Hickey, Peter J Crack

  Journal of neurochemistry. 09/2008;

  Mice deficient in the antioxidant enzyme glutathione peroxidase-1 (Gpx1) have a greater susceptibility to cerebral injury following a localised ischemic event. Much of the response toMice deficient in the antioxidant enzyme glutathione peroxidase-1 (Gpx1) have a greater susceptibility to cerebral injury following a localised ischemic event. Much of the response to ischemia-reperfusion is caused by aberrant responses within the microvasculature, including inflammation, diminished endothelial barrier function (increased vascular permeability), endothelial activation and reduced microvascular perfusion. However, the role of Gpx1 in regulating these responses has not been investigated. Wild-type and Gpx1-/- mice underwent focal cerebral ischemia via mid-cerebral artery occlusion (MCAO) followed by measurement of cerebral perfusion via laser Doppler and intravital microscopy. Post-ischemic brains in wild-type mice displayed significant deficit in microvascular perfusion. However, in Gpx1-/- mice, the deficit in cerebral blood flow was significantly greater than that in wild-type mice, and this was associated with significant increase in infarct size and increased vascular permeability. Ischemia-reperfusion also resulted in expression of matrix metalloproteinase-9 (MMP-9) in endothelial cells. The absence of Gpx1 was associated with marked increase in pro-MMP-9 expression as well as potentiated MMP-9 activity. Pretreatment of Gpx1-/- mice with the antioxidant ebselen restored microvascular perfusion, limited the induction and activation of MMP-9, and attenuated the increases in infarct size and vascular permeability. These findings demonstrate that the antioxidant function of Gpx1 plays a critical role in protecting the cerebral microvasculature against ischemia-reperfusion injury by preserving microvascular perfusion and inhibiting MMP-9 expression.

• STAT3 and STAT1 mediate IL-11-dependent and inflammation-associated gastric tumorigenesis in gp130 receptor mutant mice.

  Authors: Matthias Ernst, Meri Najdovska, Dianne Grail, Therese Lundgren-May, Michael Buchert, Hazel Tye, Vance B Matthews, Jane Armes, Prithi S Bhathal, Norman R Hughes, Eric G Marcusson, James G Karras, Songqing Na, Jonathon D Sedgwick, Paul J Hertzog, Brendan J Jenkins

  The Journal of clinical investigation. 06/2008; 118(5):1727-38.

  Deregulated activation of STAT3 is frequently associated with many human hematological and epithelial malignancies, including gastric cancer. While exaggerated STAT3 signaling facilitates anDeregulated activation of STAT3 is frequently associated with many human hematological and epithelial malignancies, including gastric cancer. While exaggerated STAT3 signaling facilitates an antiapoptotic, proangiogenic, and proproliferative environment for neoplastic cells, the molecular mechanisms leading to STAT3 hyperactivation remain poorly understood. Using the gp130(Y757F/Y757F) mouse model of gastric cancer, which carries a mutated gp130 cytokine receptor signaling subunit that cannot bind the negative regulator of cytokine signaling SOCS3 and is characterized by hyperactivation of the signaling molecules STAT1 and STAT3, we have provided genetic evidence that IL-11 promotes chronic gastric inflammation and associated tumorigenesis. Expression of IL-11 was increased in gastric tumors in gp130(Y757F/Y757F) mice, when compared with unaffected gastric tissue in wild-type mice, while gp130(Y757F/Y757F) mice lacking the IL-11 ligand-binding receptor subunit (IL-11Ralpha) showed normal gastric STAT3 activation and IL-11 expression and failed to develop gastric tumors. Furthermore, reducing STAT3 activity in gp130(Y757F/Y757F) mice, either genetically or by therapeutic administration of STAT3 antisense oligonucleotides, normalized gastric IL-11 expression and alleviated gastric tumor burden. Surprisingly, the genetic reduction of STAT1 expression also reduced gastric tumorigenesis in gp130(Y757F/Y757F) mice and coincided with reduced gastric inflammation and IL-11 expression. Collectively, our data have identified IL-11 as a crucial cytokine promoting chronic gastric inflammation and associated tumorigenesis mediated by excessive activation of STAT3 and STAT1.

• Type I interferon receptors: biochemistry and biological functions.

  Authors: Nicole A de Weerd, Shamith A Samarajiwa, Paul J Hertzog

  The Journal of biological chemistry. 08/2007; 282(28):20053-7.

• Targeting of the ETS factor GABPalpha disrupts neuromuscular junction synaptic function.

  Authors: Debra A O'Leary, Peter G Noakes, Nick A Lavidis, Ismail Kola, Paul J Hertzog, Sika Ristevski

  Molecular and cellular biology. 06/2007; 27(9):3470-80.

  The GA-binding protein (GABP) transcription factor has been shown in vitro to regulate the expression of the neuromuscular proteins utrophin, acetylcholine esterase, and acetylcholine receptorThe GA-binding protein (GABP) transcription factor has been shown in vitro to regulate the expression of the neuromuscular proteins utrophin, acetylcholine esterase, and acetylcholine receptor subunits delta and epsilon through the N-box promoter motif (5'-CCGGAA-3'), but its in vivo function remains unknown. A single point mutation within the N-box of the gene encoding the acetylcholine receptor epsilon subunit has been identified in several patients suffering from postsynaptic congenital myasthenic syndrome, implicating the GA-binding protein in neuromuscular function and disease. Since conventional gene targeting results in an embryonic-lethal phenotype, we used conditional targeting to investigate the role of GABPalpha in neuromuscular junction and skeletal muscle development. The diaphragm and soleus muscles from mutant mice display alterations in morphology and distribution of acetylcholine receptor clusters at the neuromuscular junction and neurotransmission properties consistent with reduced receptor function. Furthermore, we confirmed decreased expression of the acetylcholine receptor epsilon subunit and increased expression of the gamma subunit in skeletal muscle tissues. Therefore, the GABP transcription factor aids in the structural formation and function of neuromuscular junctions by regulating the expression of postsynaptic genes.

• Comparison of mice born after intracytoplasmic sperm injection with in vitro fertilization and natural mating.

  Authors: Trevor J Wilson, Orly Lacham-Kaplan, Jodee Gould, Andrew Holloway, Ivan Bertoncello, Paul J Hertzog, Alan Trounson

  Molecular reproduction and development. 05/2007; 74(4):512-9.

  The procedures of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are routinely used in modern medicine to overcome infertility and, in animal husbandry, to propagate linesThe procedures of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are routinely used in modern medicine to overcome infertility and, in animal husbandry, to propagate lines with compromised fertility. However, there remains concern that manual selection and injection of whole sperm into oocytes could contribute to pre- and postnatal developmental defects. To address this, we have used gene expression profiling and immunophenotyping to characterize offspring generated by these procedures. We used gametes from glutathione peroxidase 1 knockout (Gpx1-/-) mice as a sensitized screen responsive to oxidative stress from artificial reproduction technologies (ART). There were no differences between IVF and ICSI derived offspring in gene expression patterns, and minor differences in hematopoietic parameters. Furthermore there were only minor differences between these IVF and ICSI pups and those derived from natural mating. These data demonstrate for the first time in that there is no significant phenotypic affects of ICSI when compared to IVF and we identified a relatively minor influence of the artificial fertilization methods on phenotype of offspring compared with natural mating. These observations would support the use of ICSI for derivation of mutant mouse lines and may be of some importance for the use of this technique in human ART.