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RAR-related orphan receptor-γt (ROR-γt) directs differentiation of proinflammatory T helper 17 ([T.sub.H]17) cells and is a potential therapeutic target in chronic autoimmune and inflammatory diseases (1-3). However, ROR-γt-dependent group 3 innate lymphoid cells ILC3s provide essential immunity and tissue protection in the intestine (4-11), suggesting that targeting ROR-γt could also result in impaired host defense after infection or enhanced tissue damage. Here, we demonstrate that transient chemical inhibition of ROR-γt in mice selectively reduces cytokine production from [T.sub.H]17 but not ILCs in the context of intestinal infection with Oitrobaeter rodentium, resulting in preserved innate immunity. Temporal deletion of Rore (encoding ROR-γt) in mature ILCs also did not impair cytokine response in the steady state or during infection. Finally, pharmacologic inhibition of ROR-γt provided therapeutic benefit in mouse models of intestinal inflammation and reduced the frequency of [T.sub.H]17 cells but not ILCs isolated from primary intestinal samples of individuals with inflammatory bowel disease (IBD). Collectively, these results reveal differential requirements for ROR-γt in the maintenance of [T.sub.H]17 cell and ILC3 responses and suggest that transient inhibition of ROR-γt is a safe and effective therapeutic approach during intestinal inflammation., Although therapeutic targeting of the [T.sub.H]17 cell pathway is effective in several autoimmune diseases (12-14), in Crohn's disease blockade of interleukin 17A (IL-17A) is ineffective and, in some cases, associated [...]

The glucagon-like peptide-1 (GLP-1) receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor transduce nutrient-stimulated signals to control beta cell function (1). Although the GLP-1 receptor (GLP-1R) is a validated drug target for diabetes (1), the importance of the GIP receptor (GIPR) for the function of beta cells remains uncertain (2-4). We demonstrate that mice with selective ablation of GIPR in beta cells ([MIP-Cre:Gipr.sup.Flox/Flox]; [Gipr-/-.sup.βCell]) exhibit lower levels of meal-stimulated insulin secretion, decreased expansion of adipose tissue mass and preservation of insulin sensitivity when compared to M/P-Cre controls. Beta cells from [Gipr-/-.sup.βCell] mice display greater sensitivity to apoptosis and markedly lower islet expression of T cell-specific transcription factor-1 (TCF1, encoded by Tcf7), a protein not previously characterized in beta cells. GIP, but not GLP-1, promotes beta cell Tcf7 expression via a cyclic adenosine monophosphate (cAMP)-independent and extracellular signal-regulated kinase (ERK)-dependent pathway. Tcf7 (in mice) or TCF7 (in humans) levels are lower in islets taken from diabetic mice and in humans with type 2 diabetes; knockdown of TCF7 in human and mouse islets impairs the cytoprotective responsiveness to GIP and enhances the magnitude of apoptotic injury, whereas restoring TCF1 levels in beta cells from [Gipr-/-.sup.βCell] mice lowers the number of apoptotic cells compared to that seen in MIP-Cre controls. [Tcf7.sup.-/-] mice show impaired insulin secretion, deterioration of glucose tolerance with either aging and/or high-fat feeding and increased sensitivity to beta cell injury relative to wild-type (WT) controls. Hence the GIPR-TCF1 axis represents a potential therapeutic target for preserving both the function and survival of vulnerable, diabetic beta cells., The ingestion of nutrients triggers the secretion of multiple gut peptides, including GLP-1 and GIP, both of which are incretin hormones that amplify insulin secretion. GLP-1 and GIP also control [...]

Macrophage phagocytosis of tumor cells mediated by CD47-specific blocking antibodies has been proposed to be the major effector mechanism in xenograft models. Here, using syngeneic immunocompetent mouse tumor models, we reveal that the therapeutic effects of CD47 blockade depend on dendritic cell but not macrophage cross-priming of T cell responses. The therapeutic effects of anti-CD47 antibody therapy were abrogated in T cell-deficient mice. In addition, the antitumor effects of CD47 blockade required expression of the cytosolic DNA sensor STING, but neither MyD88 nor TRIF, in [CD11c.sup.+] cells, suggesting that cytosolic sensing of DNA from tumor cells is enhanced by anti-CD47 treatment, further bridging the innate and adaptive responses. Notably, the timing of administration of standard chemotherapy markedly impacted the induction of antitumor T cell responses by CD47 blockade. Together, our findings indicate that CD47 blockade drives T cell-mediated elimination of immunogenic tumors., Phagocytosis relies on a balance between prophagocytic ('eat me') and antiphagocytic ('don't eat me') signals on target cells (1-3). CD47, initially observed on stem cells, is a transmembrane protein that [...]

Genetic evidence implicates the loss of bone morphogenetic protein type II receptor (BMPR-II) signaling in the endothelium as an initiating factor in pulmonary arterial hypertension (PAH). However, selective targeting of this signaling pathway using BMP ligands has not yet been explored as a therapeutic strategy. Here, we identify BMP9 as the preferred ligand for preventing apoptosis and enhancing monolayer integrity in both pulmonary arterial endothelial cells and blood outgrowth endothelial cells from subjects with PAH who bear mutations in the gene encoding BMPR-II, BMPR2. Mice bearing a heterozygous knock-in allele of a human BMPR2 mutation, R899X, which we generated as an animal model of PAH caused by BMPR-II deficiency, spontaneously developed PAH. Administration of BMP9 reversed established PAH in these mice, as well as in two other experimental PAH models, in which PAH develops in response to either monocrotaline or VEGF receptor inhibition combined with chronic hypoxia. These results demonstrate the promise of direct enhancement of endothelial BMP signaling as a new therapeutic strategy for PAH., Heritable and idiopathic PAH are characterized by narrowing and obliteration of precapillary pulmonary arteries secondary to proliferation and apoptosis resistance of endothelial cells, smooth muscle cells and fibroblasts (1). The [...]

Neurodegenerative diseases, such as frontotemporal dementia (FTD), are often associated with behavioral deficits, but the underlying anatomical and molecular causes remain poorly understood. Here we show that forebrain-specific expression of FTD-associated mutant CHMP2B in mice causes several age-dependent neurodegenerative phenotypes, including social behavioral impairments. The social deficits were accompanied by a change in AMPA receptor (AMPAR) composition, leading to an imbalance between [Ca.sup.2+]-permeable and [Ca.sup.2+]-impermeable AMPARs. Expression of most AMPAR subunits was regulated by the brain-enriched microRNA miR-124, whose abundance was markedly decreased in the superficial layers of the cerebral cortex of mice expressing the mutant CHMP2B. We found similar changes in miR-124 and AMPAR levels in the frontal cortex and induced pluripotent stem cell-derived neurons from subjects with behavioral variant FTD. Moreover, ectopic miR-124 expression in the medial prefrontal cortex of mutant mice decreased AMPAR levels and partially rescued behavioral deficits. Knockdown of the AMPAR subunit Gria2 also alleviated social impairments. Our results identify a previously undescribed mechanism involving miR-124 and AMPARs in regulating social behavior in FTD and suggest a potential therapeutic avenue., Different neurodegenerative diseases are characterized by progressive dysfunction and loss of specific neuronal populations, often resulting in various behavioral abnormalities (1-3). The molecular mechanisms of these impairments, and the neural [...]

Background The association between vitamin D receptor (VDR) polymorphisms and asthma risk has been inconsistently investigated, but published studies demonstrated conflicting results. The aim of the current study was to investigate the impact of TaqI, BsmI, ApaI, and FokI VDR polymorphisms on asthma disease by using a meta-analysis approach. Methods Following the preferred reporting items for systematic reviews and meta-analyses guidelines, a systematic search and meta-analysis of the literature were conducted. Subgroup analyses were performed to detect potential sources of heterogeneity from selected study characteristics. Results A total of 2,097 cases and 1,968 controls in eight case-control studies were included in meta-analyses. A significant association was found between TaqI polymorphisms and asthma risk [OR 1.488 (95% CI 1.019-2.174); P = 0.040] in a codominant model. In the same way, BsmI was significantly associated with asthma risk [OR 2.017 (95% CI 1.236-3.851); P = 0.017] in the codominant model. The homozygote BB BsmI genotype was found to confer significant asthma risk. FokI polymorphism was marginally associated with asthma risk [OR 1.187 (95% CI 0.975-1.446); P = 0.088] in the codominant model. In contrast, no significant association was found between ApaI polymorphism and asthma risk. Subgroup analyses revealed that gender and age modified significantly the association between FokI polymorphisms and asthma risk (P = 0.035 and 0.013, respectively). Publication year and serum 25(OH) D level tended, marginally, to moderate the association between FokI polymorphism and asthma risk. Conclusion TaqI, BsmI, and FokI VDR polymorphisms contribute to asthma susceptibility. The association between FokI polymorphism and asthma risk is influenced by study characteristics. Keywords BsmI * ApaI * TaqI * FokI * VDR polymorphism * Asthma * Meta-analysis, Introduction Asthma is a chronic respiratory disease characterized by airway inflammation, airway hyper-responsiveness, and airflow obstruction in response to specific triggers [1, 2]. It has also an immunological component [3]. [...]

Purpose Zinc has been known to act as a signaling molecule that regulates a variety of neuronal functions. In this study, we aimed to study the effect of zinc on two populations of acid-sensitive ion channels, acid-sensing ion channels (ASICs), and transient receptor potential vanilloid receptor-1 (TRPV1), in vagal bronchopulmonary sensory neurons. Methods Rat vagal sensory neurons innervating lungs and airways were retrogradely labeled with a fluorescent tracer. Whole-cell perforated patch-clamp recordings were carried out in primarily cultured bronchopulmonary sensory neurons. The acid-evoked ASIC and TRPV1 currents were measured and compared between before and after the zinc pretreatment. Results ASIC currents were induced by a pH drop from 7.4 to 6.8 or 6.5 in the presence of capsazepine (10 µM), a specific TRPV1 antagonist. Pretreatment with zinc (50 or 300 µM, 2 min) displayed different effects on the two distinct phenotypes of ASIC currents: a marked potentiation on ASIC channels with fast kinetics of activation and inactivation or no significant effect on ASIC currents with slow activation and inactivation. On the other hand, pretreatment with zinc significantly inhibited the acid (pH 5.5 or 5.3)-induced TRPV1 currents. The inhibition was abolished by intracellular chelation of zinc by TPEN (25 µM), indicating that intracellular accumulation of zinc was likely required for its inhibitory effect on TRPV1 channels. Conclusions Our study showed that zinc differentially regulates the activities of ASICs and TRPV1 channels in rat vagal bronchopulmonary sensory neurons. Keywords Acid-sensing ion channel * Transient receptor potential vanilloid receptor-1 * Zinc * Airway acidification * Bronchopulmonary sensory neuron, Introduction Zinc is a divalent heavy metal ion and second only to iron in being the most abundant trace element in human body. The concentration of synaptically released zinc is [...]

Purpose Melanocortin 3 Receptor (MC3R) is one of the families of seven-transmembrane G-protein-coupled receptors, and a recent study showed that MCR3 promoter polymorphism was significantly associated with the susceptibility of tuberculosis (TB) in South African population. Methods We analyzed six MC3R polymorphisms to examine the genetic effects on the risk of pulmonary TB in Korean subjects by using TaqMan assays and case-control analyses. Results Using statistical analyses, one common promoter polymorphism (MC3R rs11575886 T > C) was found to be associated with an increased risk of pulmonary TB. The frequency of the C-bearing genotype of rs11575886 was higher in pulmonary TB patients than in normal controls (p = 0.03, OR = 1.46) although the significance was not retained after correction. In silico analysis for the difference of transcription binding factor (TF), motif between C and T allele demonstrated that the TF motif and its threshold scores of C allele were lower than those of T allele. Conclusions The C allele of rs11575886 could be a risk allele for the pulmonary TB by affecting the binding of TF. Our findings suggest that polymorphisms in MC3R might be one of genetic factors for the risk of pulmonary TB development in Korean subjects. Keywords MC3R * Polymorphism * Pulmonary tuberculosis Genetic factor, Introduction Tuberculosis (TB) is a major public health problem globally [1], and approximately one-third of the world's population has been infected with the bacterium, such as Mycobacterium tuberculosis, that causes [...]

Tumour metastasis is the primary cause of mortality in cancer patients and remains the key challenge for cancer therapy (1). New therapeutic approaches to block inhibitory pathways of the immune system have renewed hopes for the utility of such therapies (2). Here we show that genetic deletion of the E3 ubiquitin ligase Cbl-b (casitas B-lineage lymphoma-b) or targeted inactivation of its E3 ligase activity licenses natural killer (NK) cells to spontaneously reject metastatic tumours. The TAM tyrosine kinase receptors Tyro3, Axl and Mer (also known as Mertk) were identified as ubiquitylation substrates for Cbl-b. Treatment of wild-type NK cells with a newly developed small molecule TAM kinase inhibitor conferred therapeutic potential, efficiently enhancing anti-metastatic NK cell activity invivo. Oral or intraperitoneal administration using this TAM inhibitor markedly reduced murine mammary cancer and melanoma metastases dependent on NK cells. We further report that the anticoagulant warfarin exerts anti-metastatic activity in mice via Cbl-b/TAM receptors in NK cells, providing a molecular explanation for a 50-year-old puzzle in cancer biology (3). This novel TAM/Cbl-b inhibitory pathway shows that it might be possible to develop a 'pill' that awakens the innate immune system to kill cancer metastases., Genetic ablation of Cbl-b or functional inactivation of its E3 ligase activity in mice results in [CD8.sup.+] T-cell-mediated rejection of primary tumours in several different models (4-6). In a control [...]

Angioinvasion is a hallmark of mucormycosis. Previously, we identified endothelial cell glucose-regulated protein 78 (GRP78) as a receptor for Mucorales that mediates host cell invasion. Here we determined that spore coat protein homologs (CotH) of Mucorales act as fungal ligands for GRP78. CotH proteins were widely present in Mucorales and absent from noninvasive pathogens. Heterologous expression of CotH3 and CotH2 in Saccharomyces cerevisiae conferred the ability to invade host cells via binding to GRP78. Homology modeling and computational docking studies indicated structurally compatible interactions between GRP78 and both CotH3 and CotH2. A mutant of Rhizopus oryzae, the most common cause of mucormycosis, with reduced CotH expression was impaired for invading and damaging endothelial cells and CHO cells overexpressing GRP78. This strain also exhibited reduced virulence in a diabetic ketoacidotic (DKA) mouse model of mucormycosis. Treatment with anti-CotH Abs abolished the ability of R. oryzae to invade host cells and protected DKA mice from mucormycosis. The presence of CotH in Mucorales explained the specific susceptibility of DKA patients, who have increased GRP78 levels, to mucormycosis. Together, these data indicate that CotH3 and CotH2 func-tion as invasins that interact with host cell GRP78 to mediate pathogenic host-cell interactions and identify CotH as a promising therapeutic target for mucormycosis., Introduction Mucormycosis is a life-threatening infection with very poor out-come despite current treatment options, which include surgical debridement of infected foci and antifungal therapy (1-3). Mortality rates for mucormycosis often [...]

The B cell-specific transcription factor BACH2 is required for affinity maturation of B cells. Here we show that Bach2-mediated activation of p53 is required for stringent elimination of pre-B cells [...]

Successful pregnancy requires coordination of an array of signals and factors from multiple tissues. One such element, liver receptor homolog-1 (Lrh-1), is an orphan nuclear receptor that regulates metabolism and [...]

The nuclear receptor Rev-erb-α modulates hepatic lipid and glucose metabolism, adipogenesis and the inflammatory response in macrophages. We show here that Rev-erb-α is highly expressed in oxidative skeletal muscle and [...]

The mechanisms involved in the coordinate regulation of the metabolic and structural programs controlling muscle fitness and endurance are unknown. Recently, the nuclear receptor PPAR β/δ was shown to activate [...]

Peroxisome proliferator-activated receptors (PPARs) act as metabolic sensors and central regulators of fat and glucose homeostasis (1). Furthermore, PPARγ has been implicated as major catabolic regulator of bone mass in [...]

Glucagon-like peptide-1 receptor (GLP-1R) agonists exert antihypertensive actions through incompletely understood mechanisms. Here we demonstrate that cardiac Glp1r expression is localized to cardiac atria and that GLP-1R activation promotes the [...]

Thiazolidinediones (TZDs) are potent insulin sensitizers that act through the nuclear receptor peroxisome proliferator-activated receptor-γ (PPAR γ) and are highly effective oral medications for type 2 diabetes. However, their unique [...]

Purpose The plasminogen system plays many roles in normal epithelial cell function, and components are elevated in diseases, such as cancer and asthma. The relative contribution of each component to epithelial function is unclear. We characterized normal cell function in airway epithelial cells with increased expression of selected pathway components. Methods BEAS-2B R1 bronchial epithelial cells stably overexpressing membrane urokinase plasminogen activator receptor (muPAR), soluble spliced uPAR (ssuPAR), the ligand (uPA) or inhibitors (PAI1 or PAI2), were characterized for pathway expression. Cell function was examined using proliferation, apoptosis, and scratch wound assays. A549 alveolar epithelial cells overexpressing muPAR were similarly characterized and downstream plasmin activity, MMP-1, and MMP-9 measured. Results Elevated expression of individual components led to changes in the plasminogen system expression profile, indicating coordinated regulation of the pathway. Increased muPAR expression augmented wound healing rate in BEAS-2B R1 and attenuated repair in A549 cells. Elevated expression of other system components had no effect on cell function in BEAS-2B R1 cells. This is the first study to investigate activity of the splice variant ssuPAR, with results suggesting that this variant plays a limited role in epithelial cell function in this model. Conclusions Our data highlight muPAR as the critical molecule orchestrating effects of the plasminogen system on airway epithelial cell function. These data have implications for diseases, such as cancer and asthma, and suggest uPAR as the key therapeutic target for the pathway in approaches to alter epithelial cell function. Keywords Urokinase plasminogen activator receptor * Wound repair * Apoptosis * Proliferation * Bronchial epithelial cell lines * Asthma, Introduction The plasminogen system is an enzymatic cascade involved in the control of many normal cell functions, including proliferation, apoptosis, matrix remodelling, and migration (Fig. 1). Central to the system [...]

Coagulation is a host defense system that limits the spread of pathogens. Coagulation proteases, such as thrombin, also activate cells by cleaving PARs. In this study, we analyzed the role [...]

Hepatic insulin resistance is a driving force in the pathogenesis of type 2 diabetes mellitus (T2DM) and is tightly coupled with excessive storage of fat and the ensuing inflammation within the liver (1-3). There is compelling evidence that activation of the transcription factor nuclear factor-κB (NF-κB) and downstream inflammatory signaling pathways systemically and in the liver are key events in the etiology of hepatic insulin resistance and b-cell dysfunction, although the molecular mechanisms involved are incompletely understood (3-6). We here test the hypothesis that receptor activator of NF-κB ligand (RANKL), a prototypic activator of NF-κB, contributes to this process using both an epidemiological and experimental approach. In the prospective population-based Bruneck Study, a high serum concentration of soluble RANKL emerged as a significant (P < 0.001) and independent risk predictor of T2DM manifestation. In close agreement, systemic or hepatic blockage of RANKL signaling in genetic and nutritional mouse models of T2DM resulted in a marked improvement of hepatic insulin sensitivity and amelioration or even normalization of plasma glucose concentrations and glucose tolerance. Overall, this study provides evidence for a role of RANKL signaling in the pathogenesis of T2DM. If so, translation to the clinic may be feasible given current pharmacological strategies to lower RANKL activity to treat osteoporosis., RANKL (also known as TNFSF11) is a member of the tumor necrosis factor superfamily and, after ligation with its cognate receptor RANK (also known as TNFRSF11a), is a potent stimulator [...]

Age-related macular degeneration (AMD) is the leading cause of central vision loss worldwide. Drusen accumulation is the major pathological hallmark common to both dry and wet AMD. Although activation of the immune system has been implicated in disease progression, the pathways involved are unclear. Here we show that drusen isolated from donor AMD eyes activates the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome, causing secretion of interleukin-1β (IL-1β) and IL-18. Drusen component C1Q also activates the NLRP3 inflammasome. Moreover, the oxidative-stress-related protein-modification carboxyethylpyrrole (CEP), a biomarker of AMD, primes the inflammasome. We found cleaved caspase-1 and NLRP3 in activated macrophages in the retinas of mice immunized with CEP-adducted mouse serum albumin, modeling a dry-AMD-like pathology. We show that laser-induced choroidal neovascularization (CNV), a mouse model of wet AMD, is exacerbated in [Nlrp3.sup.-/-] but not [Il1r1.sup.-/-] mice, directly implicating IL-18 in the regulation of CNV development. These findings indicate a protective role for NLRP3 and IL-18 in the progression of AMD., In the developed world, AMD is the most prevalent cause of legal blindness in older individuals (1), (2). AMD is a progressive disease characterized by the accumulation of focal extracellular [...]

During fasting, induction of hepatic gluconeogenesis is crucial to ensure proper energy homeostasis (1). Such induction is dysregulated in type 2 diabetes, resulting in the development of fasting hyperglycemia (2). [...]

Chronic pain is highly variable between individuals, as is the response to analgesics. Although much of the variability in chronic pain and analgesic response is heritable, an understanding of the [...]

G-protein-coupled receptors are the largest class of cell-surface receptors, and these membrane proteins exist in equilibrium between inactive and active states (1-13). Conformational changes induced by extracellular ligands binding to G-protein-coupled receptors result in a cellular response through the activation of G proteins. The [A.sub.2A] adenosine receptor ([A.sub.2A]AR) is responsible for regulating blood flow to the cardiac muscle and is important in the regulation of glutamate and dopamine release in the brain (14). Here we report the raising of a mouse monoclonal antibody against human [A.sub.2A]AR that prevents agonist but not antagonist binding to the extracellular ligand-binding pocket, and describe the structure of [A.sub.2A]AR in complex with the antibody Fab fragment (Fab2838). This structure reveals that Fab2838 recognizes the intracellular surface of [A.sub.2A]AR and that its complementarity-determining region, CDR-H3, penetrates into the receptor. CDR-H3 is located in a similar position to the G-protein carboxy-terminal fragment in the active opsin structure (1) and to CDR-3 of the nanobody in the active [β.sub.2]-adrenergic receptor structure (2), but locks [A.sub.2A]AR in an inactive conformation. These results suggest a new strategy to modulate the activity of G-protein-coupled receptors., The structures of G-protein-coupled receptors (GPCRs) in an inactive conformation solved recently (3,12) greatly advance our understanding of the molecular signalling mechanisms of the receptors. The first details of GPCR [...]

Many common disorders of pregnancy are attributed to insufficient invasion of the uterine lining by trophoblast, fetal cells that are the major cell type of the placenta. Interactions between fetal trophoblast and maternal uterine NK (uNK) cells--specifically interactions between HLA-C molecules expressed by the fetal trophoblast cells and killer Ig-like receptors (KIRs) on the maternalu NK cells--influence placentation in human pregnancy. Consistent with this, pregnancies are at increased risk of preeclampsia in mothers homozygous for KIR haplotype A (KIR AA). In this study, we have demonstrated that trophoblast expresses both paternally and maternally inherited HLA-C surface proteins and that maternal KIR AA frequencies are increased in affected pregnancies only when the fetus has more group 2 HLA-C genes (C2) than the mother. These data raise the possibility that there is a deleterious allogeneic effect stemming from paternal C2.We found that this effect also occurred in other pregnancy disorders (fetal growth restriction and recurrent miscarriage), indicating a role early in gestation for these receptor/ligand pairs in the pathogenesis of reproductive failure. Notably, pregnancy disorders were less frequent in mothers that possessed the telomeric end of the KIR B haplotype, which contains activating KIR2DS1. In addition, uNK cells expressed KIR2DS1, which bound specifically to [C2.sup.+] trophoblast cells. These findings highlight the complexity and central importance of specific combinations of activating KIR and HLA-C in maternal-fetal immune interactions that determine reproductive success., Introduction The main tissue location where maternal allo-recognition of the fetus occurs is in the uterus at the site of placentation, where fetal extravillous trophoblast cells (EVTs) invade and intermingle [...]

Reciprocity of inflammation, oxidative stress and neovascularization is emerging as an important mechanism underlying numerous processes from tissue healing and remodelling to cancer progression (1,2). Whereas the mechanism of hypoxia-driven angiogenesis is well understood (3,4), the link between inflammation-induced oxidation and de novo blood vessel growth remains obscure. Here we show that the end products of lipid oxidation, ω-(2-carboxyethyl) pyrrole (CEP) and other related pyrroles (5), are generated during inflammation and wound healing and accumulate at high levels in ageing tissues in mice and in highly vascularized tumours in both murine and human melanoma. The molecular patterns of carboxyalkylpyrroles are recognized by Toll-like receptor 2 (TLR2), but not TLR4 or scavenger receptors on endothelial cells, leading to an angiogenic response that is independent of vascular endothelial growth factor. CEP promoted angiogenesis in hindlimb ischaemia and wound healing models through MyD88-dependent TLR2 signalling. Neutralization of endogenous carboxyalkyl-pyrroles impaired wound healing and tissue revascularization and diminished tumour angiogenesis. Both TLR2 and MyD88 are required for CEP-induced stimulation of Rac1 and endothelial migration. Taken together, these findings establish a new function of TLR2 as a sensor of oxidation-associated molecular patterns, providing a key link connecting inflammation, oxidative stress, innate immunity and angiogenesis., Angiogenesis can either promote host defence and tissue repair or exacerbate organ dysfunction resulting in disease. In many pathologies, angiogenesis and inflammation (6) are intimately related. Inflammatory cells release proangiogenic [...]

Obesity induced in mice by high-fat feeding activates the protein kinase Cdk5 (cyclin-dependent kinase 5) in adipose tissues. This results in phosphorylation of the nuclear receptor PPARγ (peroxisome proliferator-activated receptor γ), a dominant regulator of adipogenesis and fat cell gene expression, at serine 273. This modification of PPARγ does not alter its adipogenic capacity, but leads to dysregulation of a large number of genes whose expression is altered in obesity, including a reduction in the expression of the insulin-sensitizing adipokine, adiponectin. The phosphorylation of PPARγ by Cdk5 is blocked by anti-diabetic PPARγ ligands, such as rosiglitazone and MRL24. This inhibition works both in vivo and in vitro, and is completely independent of classical receptor transcriptional agonism. Similarly, inhibition of PPARγ phosphorylation in obese patients by rosiglitazone is very tightly associated with the anti-diabetic effects of this drug. All these findings strongly suggest that Cdk5-mediated phosphorylation of PPARγ may be involved in the pathogenesis of insulin-resistance, and present an opportunity for development of an improved generation of anti-diabetic drugs through PPARγ., Adipose tissue is at the centre of metabolic syndrome. Excessive body fat defines obesity and leads to insulin resistance, dyslipidaemia, type 2 diabetes, certain cancers and cardiovascular disease. Understanding the [...]

Glucocorticoids are widely used to treat patients with autoimmune diseases such as systemic lupus erythematosus (SLE) (1,2). However, regimens used to treat many such conditions cannot maintain disease control in the majority of SLE patients and more aggressive approaches such as high-dose methylprednisolone pulse therapy are used to provide transient reductions in disease activity (3,4). The primary anti-inflammatory mechanism of glucocorticoids is thought to be NF-κB inhibition (5). Recognition of self nucleic acids by toll-like receptors TLR7 and TLR9 on B cells and plasmacytoid dendritic cells (PDCs) is an important step in the pathogenesis of SLE (6), promoting anti-nuclear antibodies and the production of type I interferon (IFN), both correlated with the severity of disease (1,7). Following their activation by self-nucleic acid-associated immune complexes, PDCs migrate to the tissues (8,9). We demonstrate, in vitro and in vivo, that stimulation of PDCs through TLR7 and 9 can account for the reduced activity of glucocorticoids to inhibit the IFN pathway in SLE patients and in two lupus-prone mouse strains. The triggering of PDCs through TLR7 and 9 by nucleic acid-containing immune complexes or by synthetic ligands activates the NF-κB pathway essential for PDC survival. Glucocorticoids do not affect NF-κB activation in PDCs, preventing glucocorticoid induction of PDC death and the consequent reduction of systemic IFN-α levels. These findings unveil a new role for self nucleic acid recognition by TLRs and indicate that inhibitors of TLR7 and 9 signalling could prove to be effective corticosteroid-sparing drugs., SLE is an autoimmune disease characterized by chronic stimulation of the innate immune system by endogenous nucleic acids (1,6). SLE patients are often treated with strong immunosuppressive regimens' including cytotoxic [...]

Interleukin (IL)-17-producing helper T ([T.sub.H]17) cells are a distinct T-cell subset characterized by its pathological role in autoimmune diseases (1-3). IL-6 and transforming growth factor-β (TGF-β) induce [T.sub.H]17 development, in which the orphan nuclear receptors, RORγt and RORα, have an indispensable role (4-6). However, in the absence of IL-6 and TGF-β, the ectopic expression of RORγt or RORα leads to only a modest IL-17 production (5,7,8). Here we identify a nuclear IκB family member, IκBθ (encoded by the Nfkbiz gene), as a transcription factor required for [T.sub.H]17 development in mice. The ectopic expression of IκBθ in naive [CD4.sup.+] T cells together with RORγt or RORα potently induces [T.sub.H]17 development, even in the absence of IL-6 and TGF-β. Notably, [Nfkbiz.sup.-/-] mice have a defect in TH17 development and a resistance to experimental autoimmune encephalomyelitis (EAE). The T-cell-intrinsic function of IκBθ was clearly demonstrated by the resistance to EAE of the [Rag2.sup.-/-] mice into which [Nfkbiz.sup.-/-] [CD4.sup.+] T cells were transferred. In cooperation with RORγt and RORα, IκBθ enhances Il17a expression by binding directly to the regulatory region of the Il17a gene. This study provides evidence for the transcriptional mechanisms underlying [T.sub.H]17 development and points to a molecular basis for a novel therapeutic strategy against autoimmune disease., IκBθ is a nuclear protein homologous to Bcl3, which interacts with the NF-κB subunit via the ankyrin repeat domain (ARD) (9,10). In macrophages, IκBθ induced by Toll-like receptor (TLR) stimulation [...]

The aryl hydrocarbon receptor (AhR) signaling pathway regulates the production of CYP1B1 and CYP1A1, which catalyze the bioactivation of various procarcinogens. In the present study, we investigated the effect of Ginkgo biloba extract and some of its chemical constituents on CYP1B1 and CYP1A1 gene expression and AhR activity in cultured MCF-10A human mammary epithelial cells. Treatment of MCF-10A cells with noncytotoxic concentrations of G. biloba extract (25-300 µg/mL for 24 or 48 h) increased CYP1B1 and CYP1A1 mRNA expression, which was accompanied by an increase in CYPl-mediated ethoxyresorufin O-dealkylation activity. The inductive effects of G. biloba extract were attenuated by an AhR antagonist (3',4'-dimethoxyflavone). G. biloba extract (25-300 mg/mL) increased AhR-dependent reporter activity, as determined in MCF-10A cells transfected with an AhR-regulated luciferase reporter plasmid (pGudluc6.1). Bilobalide and ginkgolides A, B, C, and J were not responsible for the modulation of CYP1B1 and CYP1A1 gene expression or AhR activation by G. biloba extract. In contrast, quercetin increased CYP1B1 and CYP1A1 gene expression and activated AhR, whereas kaempferol and isorhamnetin suppressed constitutive CYP1B1 expression and antagonized AhR activation by benzo[a]pyrene. Overall, our findings provide an impetus for future investigations on the effect of G. biloba extract in CYPl-mediated chemical carcinogenesis. Key words: aryl hydrocarbon receptor, CYP1A1, CYP1B1, bilobalide, Ginkgo biloba, ginkgolide, isorhamnetin, kaempferol, quercetin. La voie de signalisation du recepteur d'hydrocarbure d'aryle (AhR) controle l'expression des cytochromes CYP1B1 et CYP1A1 qui catalysent la bioactivation de divers facteurs procarcinogenes. Dans cette etude, nous analysons les effets d'un extrait de Ginkgo biloba et de quelques-uns de ses constituants chimiques sur l'expression des genes de CYP1B1 et de CYP1A1 et sur l'activite de l'AhR dans une culture de cellules epitheeliales mammaires humaines MCF10A. Le traitement des cellules MCF-10A au moyen de concentrations non cytotoxiques d'extrait de G. biloba (25-300 µg/mL durant 24 ou 48 h) augmente l'expression de l'ARNm de CYP1B1 et de CYP1A1, accompagnee de l'augmentation de l'activite; de l'ethoxyresorufine O-dealkylation veehiculeee par le CYP1A. Les effets induits par l'extrait de G. biloba sont atteenuees par un antagoniste de l'AhR, la 3',4'-dimethoxyflavone. L'extrait de G. biloba (25-300 µg/mL) augmente l'activite; du rapporteur dependant de l'AhR, comme on le demontre dans les cellules MCF-10A transfectees par un plasmide rapporteur de la lucifeerase (pGudluc6,1) sous le controle de l'AhR. Le bilobalide et les ginkgolides A, B, C et J ne sont pas responsables de la modulation de l'expression des genes de CYP1B1 et de CYP1A1 ou de l'activation de l'AhR par l'extrait de G. biloba. En contrepartie, la querceetine augmente l'expression des genes de CYP1B1 et de CYP1A1 et active l'AhR alors que le kaempferol et l'isorhamnetine suppriment l'expression ge;nique du CYP1B1 constitutif et s'oppose a l'activation de l'AhR par le benzo[a]pyrene. Globalement, nos observations jettent les bases pour des recherches futures sur les effets de l'extrait de G. biloba sur la carcinogene;se chimique meedieee par CYP1. Mots-cles: recepteur d'hydrocarbure d'aryle, CYP1A1, CYP1B1, bilobalide, Ginkgo biloba, ginkgolide, isorhamneetine, kaempferol, quercetine. [Traduit par la Redaction], Introduction Gingko biloba, which is a member of the Ginkgoaceae family, is the oldest living tree species (Nakanishi 2005). The roots and leaves of the G. biloba tree contain bioactive [...]

Pharmacologic modulation of iron metabolism may be a potential strategy to control infection caused by the intracellular bacteria Salmonella enterica var. Typhimurium (S. typhimurium) (pages 419-424). The molecular mechanism involves [...]