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Colorectal cancer (CRC) is a major cause of cancer mortality. Whereas some patients respond well to therapy, others do not, and thus more precise, individualized treatment strategies are needed. To [...]

Synchronizing rhythms of behaviour and metabolic processes is important for cardiovascular health and preventing metabolic diseases. The nuclear receptors REV-ERB-α and REV-ERB-β have an integral role in regulating the expression of core clock proteins driving rhythms in activity and metabolism. Here we describe the identification of potent synthetic REV-ERB agonists with in vivo activity. Administration of synthetic REV-ERB ligands alters circadian behaviour and the circadian pattern of core clock gene expression in the hypothalami of mice. The circadian pattern of expression of an array of metabolic genes in the liver, skeletal muscle and adipose tissue was also altered, resulting in increased energy expenditure. Treatment of diet-induced obese mice with a REV-ERB agonist decreased obesity by reducing fat mass and markedly improving dyslipidaemia and hyperglycaemia. These results indicate that synthetic REV-ERB ligands that pharmacologically target the circadian rhythm may be beneficial in the treatment of sleep disorders as well as metabolic diseases., In mammals, most if not all tissues display a self-sustaining circadian molecular pacemaker that is responsible for aligning rhythms in various physiological functions. The suprachiasmatic nucleus (SCN) of the hypothalamus [...]

BACKGROUND: Exposure of humans to air pollutants such as ozone and particulate matter (PM) may result in airway and systemic inflammation and altered immune function. One putative mechanism may be [...]

T-helper cells that produce interleukin-17 ([T.sub.H]17 cells) are a recently identified [CD4.sup.+] T-cell subset with characterized pathological roles in autoimmune diseases (1-3). The nuclear receptors retinoic-acid-receptor-related orphan receptors α and γt (RORα and RORγt, respectively) have indispensible roles in the development of this cell type (4-7). Here we present SR1001, a high-affinity synthetic ligand--the first in a new class of compound--that is specific to both RORα and RORγt and which inhibits [T.sub.H]17 cell differentiation and function. SR1001 binds specifically to the ligand-binding domains of RORα and RORγt, inducing a conformational change within the ligand-binding domain that encompasses the repositioning of helix 12 and leads to diminished affinity for co-activators and increased affinity for co-repressors, resulting in suppression of the receptors' transcriptional activity. SR1001 inhibited the development of murine [T.sub.H]17 cells, as demonstrated by inhibition of interleukin-17A gene expression and protein production. Furthermore, SR1001 inhibited the expression of cytokines when added to differentiated murine or human [T.sub.H]17 cells. Finally, SR1001 effectively suppressed the clinical severity of autoimmune disease in mice. Our data demonstrate the feasibility of targeting the orphan receptors RORα and RORγt to inhibit specifically [T.sub.H]17 cell differentiation and function, and indicate that this novel class of compound has potential utility in the treatment of autoimmune diseases., [T.sub.H]17 cells are crucial effector cells implicated in the pathology of numerous autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease and systemic lupus erythematosis. These cells produce a [...]

The HLA-Clocus is distinct relative to the other classical HLA class I loci in that it has relatively limited polymorphism (1), lower expression on the cell surface (2,3), and more [...]

ABSTRACT Oridonin is the main bioactive constituent of the Chinese medicinal herb Isodon albescens and has been shown to have anti-neoplastic effects against a number of cancers in vitro and [...]

Gene regulatory networks (GRNs) provide system level explanations of developmental and physiological functions in the terms of the genomic regulatory code. Depending on their developmental functions, GRNs differ in their degree of hierarchy, and also in the types of modular sub-circuit of which they are composed, although there is a commonly employed sub-circuit repertoire. Mathematical modelling of some types of GRN sub-circuit has deepened biological understanding of the functions they mediate. The structural organization of various kinds of GRN reflects their roles in the life process, and causally illuminates both developmental and evolutionary process., The body plan of an animal, and hence its exact mode of development, is a property of its species and is thus encoded in the genome. Embryonic development is an [...]

Chronic myelogenous leukaemia (CML) can progress from a slow growing chronic phase to an aggressive blast crisis phase (1), but the molecular basis of this transition remains poorly understood. Here we have used mouse models of CML (2,3) to show that disease progression is regulated by the Musashi-Numb signalling axis (4,5). Specifically, we find that the chronic phase is marked by high levels of Numb expression whereas the blast crisis phase has low levels of Numb expression, and that ectopic expression of Numb promotes differentiation and impairs advanced-phase disease in vivo. As a possible explanation for the decreased levels of Numb in the blast crisis phase, we show that NUP98-HOXA9, an oncogene associated with blast crisis CML (6,7), can trigger expression of the RNA-binding protein Musashi2 (Msi2), which in turn represses Numb. Notably, loss of Msi2 restores Numb expression and significantly impairs the development and propagation of blast crisis CML in vitro and in vivo. Finally we show that Msi2 expression is not only highly upregulated during human CML progression but is also an early indicator of poorer prognosis. These data show that the Musashi-Numb pathway can control the differentiation of CML cells, and raise the possibility that targeting this pathway may provide a new strategy for the therapy of aggressive leukaemias., Chronic myelogenous leukaemia (CML) is initiated by the BCR-ABL translocation, which leads to myeloid cell expansion while allowing differentiation (8-11). Secondary translocations such as NUP98-HOXA9 or AML1-EVI1, or mutations in [...]

In both type 1 and type 2 diabetes, pancreatic islet dysfunction results in part from cytokine-mediated inflammation. The ubiquitous eukaryotic translation initiation factor 5A (eIF5A), which is the only protein to contain the amino acid hypusine, contributes to the production of proinflammatory cytokines. We therefore investigated whether eIF5A participates in the inflammatory cascade leading to islet dysfunction during the development of diabetes. As described herein, we found that eIF5A regulates iNOS levels and that eIF5A depletion as well as the inhibition of hypusination protects against glucose intolerance in inflammatory mouse models of diabetes. We observed that following knockdown of eIF5A expression, mice were resistant to β cell loss and the development of hyperglycemia in the low-dose streptozotocin model of diabetes. The depletion of eIF5A led to impaired translation of iNOS-encoding mRNA within the islet. A role for the hypusine residue of eIF5A in islet inflammatory responses was suggested by the observation that inhibition of hypusine synthesis reduced translation of iNOS-encoding mRNA in rodent β cells and human islets and protected mice against the development of glucose intolerance the low-dose streptozotocin model of diabetes. Further analysis revealed that hypusine is required in part for nuclear export of iNOS-encoding mRNA, a process that involved the export protein exportin1. These observations identify the hypusine modification of eIF5A as a potential therapeutic target for preserving islet function under inflammatory conditions., Introduction Diabetes is a disorder of glucose homeostasis that afflicts over 200 million people worldwide. Dysfunction or destruction of islet β cells appears to underlie all forms of diabetes. Whereas [...]

Mice engineered to express c-Myc in B cells (Eμ-myc mice) develop lethal lymphomas in which the gene encoding the p53 tumor suppressor is frequently mutated. Whether the p53 homolog p73 also functions as a tumor suppressor in vivo remains controversial. Here we have shown that p73 loss does not substantially affect disease onset and mortality in Eμ-myc mice. However, it does alter the phenotype of the disease. Specifically, p73 loss decreased nodal disease and increased widespread extranodal dissemination. We further found that p53 acted as the dominant tumor suppressor during the onset of Eμ-myc-driven B cell lymphomagenesis, while p73 modulated tumor dissemination and extranodal growth. Immunophenotyping and expression profiling suggested that p73 loss allowed increased maturation of malignant B cells and deregulated genes involved in lymphocyte homing and dissemination of human lymphomas. Consistent with this, p73 expression was frequently downregulated in a large cohort of human mature aggressive B cell lymphomas, and both the incidence and degree of p73 downregulation in these tumors correlated with their extranodal dissemination status. These data indicate that p73 is a modifier of Myc-driven lymphomas in mice, favoring tumor dissemination, and suggest that p73 could be a biomarker for human B cell lymphoma dissemination, a notion that can now be tested in clinicopathologic correlation studies., Introduction The p73 gene was identified through its structural homology with the p53 tumor suppressor (1), (2). Initial overexpression studies demonstrated that p73 can activate many p53-responsive genes and partly [...]

Kidney transplant recipients that develop signs of renal dysfunction or proteinuria one or more years after transplantation are at considerable risk for progression to renal failure. To assess the kidney at this time, a 'for-cause' biopsy is performed, but this provides little indication as to which recipients will go on to organ failure. In an attempt to identify molecules that could provide this information, we used micorarrays to analyze gene expression in 105 for-cause biopsies taken between 1 and 31 years after transplantation. Using supervised principal components analysis, we derived a molecular classifier to predict graft loss. The genes associated with graft failure were related to tissue injury, epithelial dedifferentiation, matrix remodeling, and TGF-β effects and showed little overlap with rejection-associated genes. We assigned a prognostic molecular risk score to each patient, identifying those at high or low risk for graft loss. The molecular risk score was correlated with interstitial fibrosis, tubular atrophy, tubulitis, interstitial inflammation, proteinuria, and glomerular filtration rate. In multivariate analysis, molecular risk score, peritubular capillary basement membrane mul-tilayering, arteriolar hyalinosis, and proteinuria were independent predictors of graft loss. In an independent validation set, the molecular risk score was the only predictor of graft loss. Thus, the molecular risk score reflects active injury and is superior to either scarring or function in predicting graft failure., Introduction Kidney transplants that develop dysfunction or proteinuria after one year following transplantation are at considerable risk for progression to renal failure (1). Certain histopathologic features, particularly interstitial fibrosis and [...]

Abs facilitate humoral immunity via the classical mechanisms of opsonization, complement activation, Ab-dependent cellular cytotoxicity, and toxin/viral neutralization. There is also evidence that some Abs mediate direct antimicrobial effects. For example, Ab binding to the polysaccharide capsule of the human pathogenic fungus Cryptococcus neoformans promotes opsonization but also inhibits polysaccharide release and biofilm formation. To investigate whether Ab binding affects C. neoformans directly, we analyzed fungal gene expression after binding of protective and nonprotective mAbs. The 2 IgM Abs and 1 IgG1 Ab tested each induced different changes in gene expression. The protective IgG1 mAb upregulated genes encoding proteins involved in fatty acid synthesis, the protective IgM mAb downregulated genes encoding proteins required for protein translation, and the nonprotective IgM mAb had modest effects on gene expression. Differences in gene expression correlated with mAb binding to different locations of the capsule. Of the 3 Abs tested, the protective IgG1 mAb bound to C. neoformans closest to the cell wall, produced specific differences in the pattern of phosphorylated proteins, caused changes in lipid metabolism, and resulted in increased susceptibility to the antifungal drug amphotericin B. These results suggest what we believe to be a new mode of action for Ab-mediated immunity and raise the possibility that immunoglobulins mediate cross talk between microbes and hosts through their effects on microbial metabolism., Introduction Current views of Ab function posit that specific immunoglobulins mediate protection against microbes by promoting phagocytosis, activating complement, neutralizing toxins and viruses, and potentiating Ab-dependent cellular toxicity. Hence, humoral [...]

Micro RNAs (miRNAs) regulate gene expression. It has been suggested that obtaining miRNA expression profiles can improve classification, diagnostic, and prognostic information in oncology. Here, we sought to comprehensively identify the miRNAs that are overexpressed in lung cancer by conducting miRNA microar-ray expression profiling on normal lung versus adjacent lung cancers from transgenic mice. We found that miR-136, miR-376a, and miR-31 were each prominently overexpressed in murine lung cancers. Real-time RT-PCR and in situ hybridization (ISH) assays confirmed these miRNA expression profiles in paired normal-malignant lung tissues from mice and humans. Engineered knockdown of miR-31, but not other highlighted miRNAs, substantially repressed lung cancer cell growth and tumorigenicity in a dose-dependent manner. Using a bioinformatics approach, we identified miR-31 target mRNAs and independently confirmed them as direct targets in human and mouse lung cancer cell lines. These targets included the tumor-suppressive genes large tumor suppressor 2 (LATS2) and PP2A regulatory subunit B alpha isoform (PPP2R2A), and expression of each was augmented by miR-31 knockdown. Their engineered repression antagonized miR-31-mediated growth inhibition. Notably, miR-31 and these target mRNAs were inversely expressed in mouse and human lung cancers, underscoring their biologic relevance. The clinical relevance of miR-31 expression was further independently and comprehensively validated using an array containing normal and malignant human lung tissues. Together, these findings revealed that miR-31 acts as an oncogenic miRNA (oncomir) in lung cancer by targeting specific tumor suppressors for repression., Introduction MicroRNAs (miRNAs) are critical regulators of gene expression (1), (2). Mature miRNAs bind target mRNAs at complementary sites in 3'-untranslated regions (3'-UTRs) or coding sequences and thereby trigger downregulation, [...]

Antibody-mediated defense against pathogens typically requires complex interactions between antibodies and other constituents of the humoral and cellular immune systems. However, recent evidence indicates that some antibodies alone can inhibit pathogen function in the absence of complement, phagocytes, or NK cells. In this issue of the JCI, McClelland et al. have begun to elucidate the molecular bases by which antibodies alone can impact pathogen growth and metabolism. They show that mAbs specific for the polysaccharide capsule of the human pathogenic fungus Cryptococcus neoformans elicit diverse effects on fungal gene expression, lipid biosynthesis, susceptibility to amphotericin B, cellular metabolism, and protein phosphorylation. These data suggest that pathogens have the capacity to generate broad metabolic responses as a result of surface binding by pathogen-specific antibodies, effects that may hold therapeutic promise., Evolving concepts of antibody defense The word immunity derives from the Latin 'immunitas' meaning exemption and has come to mean protection from disease. Immunity has been observed over the centuries [...]

Osteoblasts have recently been found to play a role in regulating glucose metabolism through secretion of osteocalcin. It is unknown, however, how this osteoblast function is regulated transcriptionally. As FoxO1 is a forkhead family transcription factor known to regulate several key aspects of glucose homeostasis, we investigated whether its expression in osteoblasts may contribute to its metabolic functions. Here we show that mice lacking Foxo1 only in osteoblasts had increased pancreatic β cell proliferation, insulin secretion, and insulin sensitivity. The ability of osteoblast-specific FoxO1 deficiency to affect metabolic homeostasis was due to increased osteocalcin expression and decreased expression of Esp, a gene that encodes a protein responsible for decreasing the bioactivity of osteocalcin. These results indicate that FoxO1 expression in osteoblasts contributes to FoxO1 control of glucose homeostasis and identify FoxO1 as a key modulator of the ability of the skeleton to function as an endocrine organ regulating glucose metabolism., Introduction Insulin, a hormone whose main function is to regulate blood glucose level, is a major endocrine regulator of energy metabolism. Insulin resistance plays a fundamental role in the pathogenesis [...]

The B cell lymphoma 2 (Bcl-2) family member Bcl-xL has a well-characterized antiapoptotic function in lymphoid cells. However, its functions in other cells--including osteoclasts, which are of hematopoietic origin--and other cellular processes remain unknown. Here we report an unexpected function of Bcl-xL in attenuating the bone-resorbing activity of osteoclasts in mice. To investigate the role of Bcl-xL in osteoclasts, we generated mice with osteoclast-specific conditional deletion of Bcl-x (referred to herein as Bcl-x cKO mice) by mating [Bcl-x.sup.[fl/fl]] mice with mice in which the gene encoding the Cre recombinase has been knocked into the cathepsin K locus and specifically expressed in mature osteoclasts. Although the Bcl-x cKO mice grew normally with no apparent morphological abnormalities, they developed substantial osteopenia at 1 year of age, which was caused by increased bone resorption. Bcl-x deficiency increased the bone-resorbing activity of osteoclasts despite their high susceptibility to apoptosis, whereas Bcl-xL overexpression produced the opposite effect. In addition, Bcl-x cKO osteoclasts displayed increased c-Src activity, which was linked to increased levels of vitronectin and fibro-nectin expression. These results suggest that Bcl-xL attenuates osteoclastic bone-resorbing activity through the decreased production of ECM proteins, such as vitronectin and fibronectin, and thus provide evidence for what we believe to be a novel cellular function of Bcl-xL., Introduction Osteoclasts are highly differentiated bone-resorbing cells of hematopoietic origin. Bone resorption is a multistep process: the initial attachment of osteoclasts to bone matrix leads to cytoskeletal reorganization, cellular polarization, [...]

New World monkeys of the genus Aotus synthesize a fusion protein (AoT5Cyp) containing tripartite motif-containing 5 (TRIM5) and cyclophilin A (CypA) that potently blocks HIV-1 infection. We attempted to generate a human HIV-1 inhibitor modeled after AoT5Cyp, by fusing human CypA to human TRIM5 (hT5Cyp). Of 13 constructs, 3 showed substantial HIV-1-inhibitory activity when expressed in human cell lines. This activity required capsid binding by CypA and correlated with CypA linkage to the TRIM5a capsid-specificity determinant and the ability to form cytoplasmic bodies. CXCR4-and CCR5-tropic HIV-1 clones and primary isolates were inhibited from infecting multiple human macrophage and T cell lines and primary cells by hT5Cyp, as were [HIV-2.sub.ROD], [SIV.sub.AGM]tan, [FIV.sub.PET], and a circulating HIV-1 isolate previously reported to be AoT5Cyp resistant. The anti-HIV-1 activity of hT5Cyp was surprisingly more effective than that of the well-characterized rhesus TRIM5α, especially in T cells. hT5Cyp also blocked HIV-1 infection of primary [CD4.sup.+] T cells and macrophages and conferred a survival advantage to these cells without disrupting their function. Extensive attempts to elicit HIV-1 resistance to hT5Cyp were unsuccessful. Finally, [Rag2.sup.[-/-]]γ[c.sup.[-/-]] mice were engrafted with human [CD4.sup.+] T cells that had been transduced by optimized lentiviral vectors bearing hT5Cyp. Upon challenge with HIV-1, these mice showed decreased viremia and productive infection in lymphoid organs and preserved numbers of human [CD4.sup.+] T cells. We conclude that hT5Cyp is an extraordinarily robust inhibitor of HIV-1 replication and a promising anti-HIV-1 gene therapy candidate., Introduction Over 60 million people have been infected with HIV-1, and nearly half of these people have died as a consequence of this infection (1). Despite the discovery 25 years [...]

Endogenous expression of tailored nanoparticles in cells followed by application of low-frequency radio waves or a magnetic field can be used to noninvasively modulate gene expression. This approach successfully induces [...]