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Investigation of the metabolome of the ascomycete Annulohypoxylon truncatum led to the identification of novel oxygenated brasilane glycosides and the revision of the stereochemistry of the brasilane A octahydro-1H-indene core scaffold to trans. The bra biosynthetic gene cluster containing five genes (braA–braE) was identified and verified by heterologous expression experiments in Aspergillus oryzae demonstrating that BraC is a multifunctional P450 monooxygenase. In vitro studies of BraB revealed it to be a very rare fungal UDP-GlcNAc dependent N-acetylglucosamine transferase. UDP-glucose is also accepted as a donor, and a broad acceptor substrate tolerance for various primary and secondary alcohols was observed.

Background COPD patients have increased risk of pneumonia when treated with fluticasone propionate (FP), whereas this is generally not the case with budesonide (BUD) treatment. We hypothesized that BUD and FP differentially affect the expression of immune defense genes. Methods Human bronchial epithelial 16HBE cells and air-liquid interface (ALI)-cultured primary bronchial epithelial cells (PBECs) were pre-treated with clinically equipotent concentrations of BUD or FP (0.16–16 nM BUD and 0.1–10 nM FP), and the expression of immune defense genes was studied at baseline and after exposure to rhinovirus (RV16). Results Using microfluidic cards, we observed that both BUD and FP significantly suppressed CXCL8, IFNB1 and S100A8 mRNA expression in unstimulated 16HBE cells. Interestingly, BUD, but not FP, significantly increased lactotransferrin (LTF) expression. The difference between the effect of BUD and FP on LTF expression was statistically significant and confirmed by qPCR and at the protein level by western blotting. RV16 infection of ALI-cultured PBECs significantly increased the expression of CCL20, IFNB1 and S100A8, but not of LTF or CAMP/LL-37. In these RV16-exposed cells, LTF expression was again significantly higher upon pre-treatment with BUD than with FP. The same was observed for S100A8, but not for CCL20, IFNB1 or CAMP/LL-37 expression. Conclusions Treatment of human bronchial epithelial cells with BUD results in significantly higher expression of specific immune defense genes than treatment with FP. The differential regulation of these immune defense genes may help to explain the clinical observation that BUD and FP treatment differ with respect to the risk of developing pneumonia in COPD.

Background: Glucocorticoids act on the glucocorticoid receptor (GR; NR3C1) to resolve inflammation and, as inhaled corticosteroids (ICS), are the cornerstone of treatment for asthma. However, reduced efficacy in severe disease or exacerbations indicates a need to improve ICS actions. Methods: Glucocorticoid-driven transcriptomes were compared using PrimeView microarrays between primary human bronchial epithelial (HBE) cells and the model cell lines, pulmonary type II A549 and bronchial epithelial BEAS-2B cells. Results: In BEAS-2B cells, budesonide induced (≥2-fold, P ≤ 0.05) or, in a more delayed fashion, repressed (≤0.5-fold, P ≤ 0.05) the expression of 63, 133, 240, and 257 or 15, 56, 236, and 344 mRNAs at 1, 2, 6, and 18 h, respectively. Within the early-induced mRNAs were multiple transcriptional activators and repressors, thereby providing mechanisms for the subsequent modulation of gene expression. Using the above criteria, 17 (BCL6, BIRC3, CEBPD, ERRFI1, FBXL16, FKBP5, GADD45B, IRS2, KLF9, PDK4, PER1, RGCC, RGS2, SEC14L2, SLC16A12, TFCP2L1, TSC22D3) induced and 8 (ARL4C, FLRT2, IER3, IL11, PLAUR, SEMA3A, SLC4A7, SOX9) repressed mRNAs were common between A549, BEAS-2B and HBE cells at 6 h. As absolute gene expression change showed greater commonality, lowering the cut-off (≥1.25 or ≤ 0.8-fold) within these groups produced 93 induced and 82 repressed genes in common. Since large changes in few mRNAs and/or small changes in many mRNAs may drive function, gene ontology (GO)/pathway analyses were performed using both stringency criteria. Budesonide-induced genes showed GO term enrichment for positive and negative regulation of transcription, signaling, proliferation, apoptosis, and movement, as well as FOXO and PI3K-Akt signaling pathways. Repressed genes were enriched for inflammatory signaling pathways (TNF, NF-κB) and GO terms for cytokine activity, chemotaxis and cell signaling. Reduced growth factor expression and effects on proliferation and apoptosis were highlighted. Conclusions: While glucocorticoids repress mRNAs associated with inflammation, prior induction of transcriptional activators and repressors may explain longer-term responses to these agents. Furthermore, positive and negative effects on signaling, proliferation, migration and apoptosis were revealed. Since many such gene expression changes occurred in human airways post-ICS inhalation, the effects observed in cell lines and primary HBE cells in vitro may be relevant to ICS in vivo.

NK cells are innate immune lymphocytes that express a vast repertoire of germ-line encoded receptors for target recognition. These receptors include inhibitory and activating proteins, among the latter of which is CD16, a low affinity binding Fc receptor. Here, we show that human NK cells expand in response to stimulation with various tumor cell lines. We further demonstrate that the tumor-derived expansion of NK cells is accompanied by rapid, cell-dependent, changes in CD16 expression levels. We show that in NK cells expanded in response to the EBV-transformed cell line 721.221, CD16 is shed and therefore approximately half of the expanded 721.221-derived NK-cell population does not express CD16. We also show, in contrast, that in response to 1106mel cells, CD16 expression is maintained on the cell surface of the expanded NK cells due to an antibody-dependent mechanism. Our results may provide a basis for the selective expansion of NK cells that may be used for tumor immunotherapy.

Exacerbations of asthma, a chronic inflammatory respiratory disease, are associated with viral upper respiratory tract infections involving human rhinovirus. Although glucocorticoids (corticosteroids) effectively control airways inflammation in many asthmatics, human rhinovirus-associated exacerbations show reduced glucocorticoid responsiveness. Using human bronchial epithelial BEAS-2B cells, we show that human rhinovirus reduced glucocorticoid-inducible activation of glucocorticoid response element (GRE) reporter systems in a time- and concentration-dependent manner. The synthetic double-stranded viral RNA mimetic, polyinosinic:polycytidylic acid (poly(I:C)), also reduced activation of GRE reporter systems in BEAS-2B and pulmonary A549 cells. In addition, poly(I:C) decreased transcription from cAMP response element (CRE)-, TATA-, simian virus 40- and nuclear factor-kappa B (NF-κB)-dependent reporter systems. The effects of poly(I:C) on GRE-reporter activation were countered by the long-acting β2-adrenoceptor agonists, formoterol and salmeterol. Likewise, increased expression of the gene cyclin-dependent kinase inhibitor 1C (CDKN1C; p57(KIP2)) by dexamethasone was reduced by poly(I:C), but was substantially enhanced by the addition of formoterol. Poly(I:C) induced the expression of interleukin-8 (IL8; CXCL8) and this was significantly decreased by dexamethasone, formoterol or their combination. This confirms that not all transcriptional responses were attenuated by poly(I:C) and that decreased glucocorticoid-dependent transcription can be counteracted by the addition of long-acting β2-adrenoceptor agonists. These data show how human rhinovirus may attenuate glucocorticoid-induced transcription to reduce anti-inflammatory activity. However, addition of long-acting β2-adrenoceptor agonist to the glucocorticoid functionally restored this response and shows how glucocorticoid plus long-acting β2-adrenoceptor agonist combinations may prove beneficial during virus-induced exacerbations of asthma.

Rationale: COPD patients have a high risk of community-acquired pneumonia (CAP). We studied Streptococcus pneumoniae (SP) and non-typeable Haemophilus influenzae (NTHI) effects on COPD macrophage responses and how budesonide (BUD) and fluticasone propionate (FP) alter host-pathogen interactions. Methods: Blood monocytes from 10 controls, 20 healthy smokers and moderate-severe COPD [19 current smokers (CS), 21 ex-smokers (ES)] were cultured with GM-CSF to generate monocyte-derived macrophages (MDM). MDM were pre-treated with 10nM BUD, FP or vehicle for 24h and exposed to live SP or NTHI. After 24h cell surface bacterial recognition receptor expression was analyzed by flow cytometry and supernatant cytokines by bead array. Data at p≤0.05 (2-sided paired t-test) are shown. Results: SP and NTHI reduced receptor expression on MDM from COPD (mainly in ES) and healthy smokers but not controls. SP and NTHI reduced SRA-1 in CS & ES and MARCO in ES. SP also reduced CD1d, TLR2 and TLR4 in CS & ES and CD93 in ES. NTHI also reduced CD11b in CS & ES and CD35 and CD206 in ES. BUD prevented reductions by SP on SRA-1 and by NTHI on CD206, both in ES. FP prevented SP reductions of TLR2 in CS & ES and TLR4 in ES but had no effect on reductions by NTHI. BUD and FP inhibited NTHI- and SP-induced cytokines. Conclusions: Reduction of bacterial recognition receptors on macrophages may be part of the enhanced risk of CAP in COPD. BUD prevented receptor reductions induced in ex-smokers by both SP and NTHI while FP affected only SP-induced reductions. These differential effects may contribute to the difference in pneumonia risk between inhaled BUD and FP treatments in COPD. Support: AstraZeneca.

Although inhaled glucocorticoids, or corticosteroids (ICS), are generally effective in asthma, understanding their anti‐inflammatory actions in vivo remains incomplete. To characterize glucocorticoid‐induced modulation of gene expression in the human airways, we performed a randomized placebo‐controlled crossover study in healthy male volunteers. Six hours after placebo or budesonide inhalation, whole blood, bronchial brushings, and endobronchial biopsies were collected. Microarray analysis of biopsy RNA, using stringent (≥2‐fold, 5% false discovery rate) or less stringent (≥1.25‐fold, P ≤ 0.05) criteria, identified 46 and 588 budesonide‐induced genes, respectively. Approximately two third of these genes are transcriptional regulators (KLF9, PER1, TSC22D3, ZBTB16), receptors (CD163, CNR1, CXCR4, LIFR, TLR2), or signaling genes (DUSP1, NFKBIA, RGS1, RGS2, ZFP36). Listed genes were qPCR verified. Expression of anti‐inflammatory and other potentially beneficial genes is therefore confirmed and consistent with gene ontology (GO) terms for negative regulation of transcription and gene expression. However, GO terms for transcription, signaling, metabolism, proliferation, inflammatory responses, and cell movement were also associated with the budesonide‐induced genes. The most enriched functional cluster indicates positive regulation of proliferation, locomotion, movement, and migration. Moreover, comparison with the budesonide‐induced expression profile in primary human airway epithelial cells shows considerable cell type specificity. In conclusion, increased expression of multiple genes, including the transcriptional repressor, ZBTB16, that reduce inflammatory signaling and gene expression, occurs in the airways and blood and may contribute to the therapeutic efficacy of ICS. This provides a previously lacking insight into the in vivo effects of ICS and should promote strategies to improve glucocorticoid efficacy in inflammatory diseases.

The inflammatory processes associated with pulmonary disorders remains incompletely understood. CCAAT/enhancer-binding protein (C/EBP)β is implicated in inflammatory lung disorders as well as in β(2)-adrenoceptor signaling. We hypothesized that C/EBPβ in the lung epithelium contributes to lipopolysaccharide (LPS)-induced airway neutrophilia and expression of neutrophil chemoattractant chemokine (C-X-C) motif ligand (CXCL)1, as well as the suppressive effects of long-acting β(2)-agonists (LABAs) and glucocorticoids (GCs). To investigate this, mice with a lung epithelial-specific deletion of C/EBPβ (Cebpb(ΔLE)) and control littermates (Cebpb(fl/fl)) were pre-treated with a LABA, formoterol and/or a GC, budesonide, and challenged with LPS. Inflammatory cell recruitment in bronchoalveolar lavage (BAL) fluid and pulmonary expression of inflammatory mediators were investigated. In addition, the ability of formoterol to increase C/EBP transactivation was assessed in vitro. LPS-challenged Cebpb(ΔLE) mice exhibited fewer BAL neutrophils and lower pulmonary expression of CXCL1 versus Cebpb(fl/fl) mice. Suppression of LPS-induced neutrophilia by formoterol was impaired in Cebpb(ΔLE) mice and Cxcl1 expression was increased. However, suppression of the neutrophilia by budesonide with/without formoterol was preserved. Further studies indicated that C/EBP transactivation was increased by the cAMP elevating agent forskolin and formoterol in a β(2)-adrenoceptor dependent manner. Thus, C/EBPβ in the lung epithelium contributes to LPS-induced CXCL1 expression and airway neutrophilia as well as to the suppressive effects of formoterol. Reduced C/EBPβ activity, observed in smokers with chronic obstructive pulmonary disease, may impair the responsiveness to LABAs when used without GCs.

The reasons for enhanced deposition of extracellular matrix in the airways of asthmatic patients and the subsequent consequences on lung function are uncertain. Here, we investigated the synthesis of procollagen I and proteoglycans, the activity of various metalloproteinases (MMPs) and the production of their inhibitor TIMP-1 in biopsy-derived bronchial fibroblasts from eight patients with stable mild-to-moderate asthma, and how they are related to patients' lung function and airway hyperreactivity (AHR). Following 24-h fibroblast incubation in 0.4% serum, procollagen I carboxyterminal propeptide (PICP), TIMP-1 and MMP-1 in cell media were analysed by ELISA, MMP-2, MMP-3, MMP-9 by zymography and total proteoglycan production by [(35)S]-sulphate-incorporation/ion chromatography. Patients' FEV(1)% predicted and methacholine log PD(20) negatively correlated with PICP synthesized by patients' bronchial fibroblasts (r = -0.74 and r = -0.71, respectively). PICP and proteoglycan amounts positively correlated (0.8

Allergic asthma is characterized by airway inflammation in response to chronic allergen exposure, resulting in remodeling of the airway wall accompanied by dysfunctional airway physiology. However, a link between the immune-inflammatory response to allergen and changes to airway structure and physiology has not yet been fully elucidated. Moreover, the impact of inhaled corticosteroids and β2-agonists, the primary pharmacotherapy for asthma, on this process has not been completely evaluated. In this study, we employed a murine model of chronic exposure to a common environmental aeroallergen, house dust mite, to recapitulate the phenotype of clinical asthma. By examining the therapeutic effects of corticosteroid/β2-agonist combination therapy with budesonide/formoterol (BUD/FORM) in this model of airway disease, we endeavored to determine the impact of BUD/FORM on lung inflammation, structure, and physiology. BUD/FORM was delivered either while allergen exposure was ongoing (concurrent therapy) or following the cessation of allergen exposure (postexposure therapy). Our results show that airway inflammation was substantially reduced in BUD/FORM-treated mice in the concurrent therapy group, whereas in the postexposure therapy group airway inflammation spontaneously resolved. In contrast, BUD/FORM was most effective in resolving several aspects of airway remodeling and bronchial hyperreactivity when delivered in conjunction with allergen withdrawal. This study demonstrates that although both BUD/FORM therapy and allergen avoidance independently reduce airway inflammation, only BUD/FORM therapy in conjunction with allergen avoidance can effectively reverse airway remodeling and bronchial hyperreactivity induced by chronic allergen exposure.

We have defined some of the mechanisms by which the kinase inhibitor lapatinib kills HCT116 cells. Lapatinib inhibited radiation-induced activation of ERBB1/2, extracellular signal-regulated kinases 1/2, and AKT, and radiosensitized HCT116 cells. Prolonged incubation of HCT116 cells with lapatinib caused cell killing followed by outgrowth of lapatinib-adapted cells. Adapted cells were resistant to serum starvation-induced cell killing and were cross-resistant to multiple therapeutic drugs. Lapatinib was competent to inhibit basal and epidermal growth factor (EGF)-stimulated ERBB1 phosphorylation in adapted cells. Coexpression of dominant-negative ERBB1 and dominant-negative ERBB2 inhibited basal and EGF-stimulated ERBB1 and ERBB2 phosphorylation in parental and adapted cells. However, in neither parental nor adapted cells did expression of dominant-negative ERBB1 and dominant-negative ERBB2 recapitulate the cell death-promoting effects of lapatinib. Adapted cells had increased expression of MCL-1, decreased expression of BAX, and decreased activation of BAX and BAK. Overexpression of BCL-XL protected parental cells from lapatinib toxicity. Knockdown of MCL-1 expression enhanced lapatinib toxicity in adapted cells that was reverted by knockdown of BAK expression. Inhibition of caspase function modestly reduced lapatinib toxicity in parental cells, whereas knockdown of apoptosis-inducing factor expression suppressed lapatinib toxicity. Thus, in HCT116 cells, lapatinib adaptation can be mediated by altered expression of pro- and antiapoptotic proteins that maintain mitochondrial function.

Transforming growth factor beta (TGFbeta) plays a dual role in oncogenesis, acting as both a tumor suppressor and a tumor promoter. These disparate processes of suppression and promotion are mediated primarily by Smad and non-Smad signaling, respectively. A central issue in understanding the role of TGFbeta in the progression of epithelial cancers is the elucidation of the mechanisms underlying activation of non-Smad signaling cascades. Because the potent lipid mediator sphingosine-1-phosphate (S1P) has been shown to transactivate the TGFbeta receptor and activate Smad3, we examined its role in TGFbeta activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and promotion of migration and invasion of esophageal cancer cells. Both S1P and TGFbeta activate ERK1/2, but only TGFbeta activates Smad3. Both ligands promoted ERK1/2-dependent migration and invasion. Furthermore, TGFbeta rapidly increased S1P, which was required for TGFbeta-induced ERK1/2 activation, as well as migration and invasion, since downregulation of sphingosine kinases, the enzymes that produce S1P, inhibited these responses. Finally, our data demonstrate that TGFbeta activation of ERK1/2, as well as induction of migration and invasion, is mediated at least in part by ligation of the S1P receptor, S1PR2. Thus, these studies provide the first evidence that TGFbeta activation of sphingosine kinases and formation of S1P contribute to non-Smad signaling and could be important for progression of esophageal cancer.

The majority of children infected with human immunodeficiency virus live in resource-constrained settings and die without an established diagnosis. Definitive laboratory diagnosis in children younger than 12-18 months requires virologic testing; however, antibody testing is often the only option available. Antibody testing provides a definitive diagnosis in older children but is frequently not used. Children meeting clinical criteria should be treated regardless of availability of laboratory diagnoses.

Human polymorphonuclear leukocytes (PMN) have been reported to completely lack of DNA-dependent protein kinase (DNA-PK) which is composed of Ku protein and the catalytic subunit DNA-PKcs, needed for nonhomologous end-joining (NHEJ) of DNA double-strand breaks. Promyelocytic HL-60 cells express a variant form of Ku resulting in enhanced radiation sensitivity. This raises the question if low efficiency of NHEJ, instrumental for the cellular repair of oxidative damage, is a normal characteristic of myeloid differentiation. Here we confirmed the complete lack of DNA-PK in PMN protein extracts, and the expression of the truncated Ku86 variant form in HL-60. However, this degradation of DNA-PK was shown to be due to a DNA-PK-degrading protease in PMN and HL-60. In addition, by using a protease-resistant whole cell assay, both Ku86 and DNA-PKcs could be demonstrated in PMN, suggesting the previously reported absence in PMN of DNA-PK to be an artefact. The levels of Ku86 and DNA-PKcs were much reduced in PMN, as compared with that of the lymphocytes, whereas HL-60 displayed a markedly elevated DNA-PK concentration. In conclusion, our findings provide evidence of reduced, not depleted expression of DNA-PK during the mature stages of myeloid differentiation.

Paclitaxel (Taxol)-induced cell death requires the intrinsic cell death pathway, but the specific participants and the precise mechanisms are poorly understood. Previous studies indicate that a BH3-only protein BIM (BCL-2 Interacting Mediator of cell death) plays a role in paclitaxel-induced apoptosis. We show here that BIM is dispensable in apoptosis with paclitaxel treatment using bim(-/-) MEFs (mouse embryonic fibroblasts), the bim(-/-) mouse breast tumor model, and shRNA-mediated down-regulation of BIM in human breast cancer cells. In contrast, both bak (-/-) MEFs and human breast cancer cells in which BAK was down-regulated by shRNA were more resistant to paclitaxel. However, paclitaxel sensitivity was not affected in bax(-/-) MEFs or in human breast cancer cells in which BAX was down-regulated, suggesting that paclitaxel-induced apoptosis is BAK-dependent, but BAX-independent. In human breast cancer cells, paclitaxel treatment resulted in MCL-1 degradation which was prevented by a proteasome inhibitor, MG132. A Cdk inhibitor, roscovitine, blocked paclitaxel-induced MCL-1 degradation and apoptosis, suggesting that Cdk activation at mitotic arrest could induce subsequent MCL-1 degradation in a proteasome-dependent manner. BAK was associated with MCL-1 in untreated cells and became activated in concert with loss of MCL-1 expression and its release from the complex. Our data suggest that BAK is the mediator of paclitaxel-induced apoptosis and could be an alternative target for overcoming paclitaxel resistance.

Bradykinin (BK) induces differentiation of lung fibroblasts into myofibroblasts, which play an important role in extracellular matrix remodeling in the airways of asthmatic patients. It is unclear whether this process is affected by antiasthma therapies. Here, we evaluated whether a glucocorticoid, budesonide (BUD), and a long-acting β2-agonist, formoterol (FM), either alone or in combination, modified BK-induced lung fibroblast differentiation, and affected the BK-activated intracellular signaling pathways.Human fetal lung fibroblasts were incubated with BUD (0.001-0.1 μM) and/or FM (0.0001-0.1 μM) before exposure to BK (0.1 or 1 μM). Fibroblast differentiation into α-smooth-muscle-actin-positive (α-SMA⁺) myofibroblasts, BK2 receptor (B2R) expression, extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation (p-ERK1/2), intracellular Ca²⁺ concentration ([Ca²⁺]i), and p65 nuclear factor kappa B translocation were evaluated.BUD (0.1 μM) and FM (0.1 μM), either alone or in combination, completely inhibited BK-induced α-SMA protein expression and decreased the numbers of α-SMA⁺ fibroblasts, with a clear reduction in α-SMA stress fibers organization. BUD also completely inhibited the increase of B2R, whereas FM with or without BUD had no effect. BK-induced increases of [Ca²⁺]i and p-ERK1/2 were significantly reduced to similar levels by BUD and FM, either alone or in combination, whereas p65 translocation was completely inhibited by all treatments.Both BUD and FM, either alone or in combination, effectively inhibited the BK-induced differentiation of fibroblasts into α-SMA⁺ myofibroblasts and the intracellular signaling pathways involved in fibroblast activation. These results suggest that BUD and FM combination therapy has potential to inhibit fibroblast-dependent matrix remodeling in the airways of asthmatic patients.

Background Recent evidence suggests that several human cancers are capable of uncoupling of mitochondrial ATP generation in the presence of intact tricarboxylic acid (TCA) enzymes. The goal of the current study was to test the hypothesis that ketone bodies can inhibit cell growth in aggressive cancers and that expression of uncoupling protein 2 is a contributing factor. The proposed mechanism involves inhibition of glycolytic ATP production via a Randle-like cycle while increased uncoupling renders cancers unable to produce compensatory ATP from respiration. Methods Seven aggressive human cancer cell lines, and three control fibroblast lines were grown in vitro in either 10 mM glucose medium (GM), or in glucose plus 10 mM acetoacetate [G+AcA]. The cells were assayed for cell growth, ATP production and expression of UCP2. Results There was a high correlation of cell growth with ATP concentration (r = 0.948) in a continuum across all cell lines. Controls demonstrated normal cell growth and ATP with the lowest density of mitochondrial UCP2 staining while all cancer lines demonstrated proportionally inhibited growth and ATP, and over-expression of UCP2 (p < 0.05). Conclusion Seven human cancer cell lines grown in glucose plus acetoacetate medium showed tightly coupled reduction of growth and ATP concentration. The findings were not observed in control fibroblasts. The observed over-expression of UCP2 in cancer lines, but not in controls, provides a plausible molecular mechanism by which acetoacetate spares normal cells but suppresses growth in cancer lines. The results bear on the hypothesized potential for ketogenic diets as therapeutic strategies.

Liver X receptors (LXRs) alpha and beta are nuclear receptors, which form obligate heterodimers with the retinoid X receptor (RXR). The LXRs regulate both redundantly and non-redundantly the transcription of genes controlling cholesterol metabolism and transport as well as lipogenesis. Previously, we showed that mutations in putative N-terminal nuclear localization sequences (NLSs) within both LXRs inhibit nuclear import. Through in vitro studies, we show here that these NLSs bind importin alpha and are both necessary and sufficient for the nuclear import of LXRs. Imaging, transactivation, and electro-mobility shift experiments show that RXR rescues the nuclear import of the LXRalpha NLS mutant yet does not restore its transcriptional activity despite intact DNA binding. In contrast, RXR partially rescues the import of the LXRbeta NLS mutant, but has no effect on its transcriptional activity due to the loss of DNA binding. Experiments with NLS mutant RXR confirmed that RXR may dominate the nuclear import of the RXR/LXRalpha heterodimer, whereas LXRbeta dominates the nuclear import of the RXR/LXRbeta heterodimer. Intriguingly, our data indicate differences between LXRalpha and LXRbeta in their interaction with RXR and in the role their NLSs play in transactivating functions independent of nuclear import.

Many neurodegenerative disorders are accompanied by chronic glial activation, which is characterized by the abundant production of proinflammatory cytokines, such as IL-1β. IL-1β disrupts Ca2+homeostasis and stimulates astrocyte reactivity. The mechanisms by which IL-1β induces Ca2+dysregulation are not completely defined. Here, we examined how acute and chronic (24–48 h) treatment with IL-1β affect Ca2+homeostasis in freshly dissociated and primary cultured mouse cortical astrocytes. Cytosolic free Ca2+concentration ([Ca2+]cyt) was measured with fura-2 using digital imaging. An acute application of 10 ng/ml IL-1β induced Ca2+mobilization from intracellular stores and activated store-operated Ca2+entry (SOCE) and receptor-operated Ca2+entry (ROCE) in both freshly dissociated and cultured actrocytes. Treatment of cultured astrocytes with IL-1β for 24 and 48 h elevated resting [Ca2+]cyt, decreased Ca2+store content [associated with sarco(endo)plasmic reticulum Ca2+-ATPase 2b downregulation], and augmented ROCE. Based on evidence that receptor-operated, but not store-operated Ca2+channels are Ba2+permeable, Ba2+entry was used to distinguish receptor-operated Ca2+channels from store-operated Ca2+channels. ROCE was activated by the diacylglycerol analog, 1-oleoyl-2-acetyl- sn-glycerol (OAG). In the presence of extracellular Ba2+, OAG-induced elevations of cytosolic Ba2+(fura-2 340-to-380-nm ratio) were significantly larger in astrocytes treated with IL-1β. These changes in IL-1β-treated astrocytes correlate with augmented expression of transient receptor potential cation channel (TRPC)6 protein, which likely mediates ROCE. Knockdown of the TRPC6 gene markedly reduced ROCE. The data suggest that IL-1β-induced dysregulation of Ca2+homeostasis is the result of enhanced ROCE and TRPC6 expression. The disruption of Ca2+homeostasis appears to be an upstream component in the cascade of IL-1β-activated pathways leading to neurodegeneration.

Proteoglycans contribute to extracellular matrix remodeling in asthmatic airways. We investigated the effects of budesonide, a glucocorticoid, and formoterol, a long-acting beta2-adrenergic agonist, on serum-induced proteoglycan production by human lung fibroblasts. In 10% serum, total proteoglycan production was increased 1.5-fold (P0.01) compared with basal production in 0.4% serum. Budesonide (10(-8) M) reduced this increase by 44% (P0.01) and, whereas formoterol (10(-10)-10(-8) M) had no inhibitory effects, the drug combination abolished the increase (P0.01) without affecting fibroblast proliferation. This synergistic effect required functional glucocorticoid and beta-adrenergic receptors. The production of the proteoglycans decorin, biglycan, perlecan, and versican was increased 2.5- to 5-fold (P0.01) in 10% serum. Combination treatment with budesonide (10(-8) M) and formoterol (10(-10) M) abolished this increase to a significantly greater extent than either drug alone. In 10% serum, only versican mRNA was increased 1.4-fold (P0.05), whereas decorin mRNA was reduced to 39% (P0.01) of basal expression. These serum effects were counteracted by the drug combination, but there were no significant differences between the combination and either drug alone. Thus, the budesonide and formoterol combination seems to synergistically control serum-induced proteoglycan production, primarily at the post-transcriptional level. In conclusion, the proteoglycan upregulation characteristic of asthmatic airways may be limited by combination therapy with budesonide and formoterol.

Acting on the glucocorticoid receptor (NR3C1), glucocorticoids are widely used to treat inflammatory diseases. However, glucocorticoid resistance often leads to suboptimal asthma control. Since glucocorticoid-induced gene expression contributes to glucocorticoid activity, the aim of this study was to use a 2 × glucocorticoid response element (GRE) reporter and glucocorticoid-induced gene expression to investigate approaches to combat cytokine-induced glucocorticoid resistance. Pre-treatment with tumor necrosis factor-α (TNF) or interleukin-1β inhibited dexamethasone-induced mRNA expression of the putative anti-inflammatory genes RGS2 and TSC22D3, or just TSC22D3, in primary human airway epithelial and smooth muscle cells, respectively. Dexamethasone-induced DUSP1 mRNA was unaffected. In human bronchial epithelial BEAS-2B cells, dexamethasone-induced TSC22D3 and CDKN1C expression (at 6 h) was reduced by TNF pre-treatment, whereas DUSP1 and RGS2 mRNAs were unaffected. TNF pre-treatment also reduced dexamethasone-dependent 2×GRE reporter activation. This was partially reversed by PS-1145 and c-jun N-terminal kinase (JNK) inhibitor VIII, inhibitors of IKK2 and JNK, respectively. However, neither inhibitor affected TNF-dependent loss of dexamethasone-induced CDKN1C or TSC22D3 mRNA. Similarly, inhibitors of the extracellular signal-regulated kinase, p38, phosphoinositide 3-kinase or protein kinase C pathways failed to attenuate TNF-dependent repression of the 2×GRE reporter. Fluticasone furoate, fluticasone propionate and budesonide were full agonists relative to dexamethasone, while GSK9027, RU24858, des-ciclesonide and GW870086X were partial agonists on the 2×GRE reporter. TNF reduced reporter activity in proportion with agonist efficacy. Full and partial agonists showed various degrees of agonism on RGS2 and TSC22D3 expression, but were equally effective at inducing CDKN1C and DUSP1, and did not affect the repression of CDKN1C or TSC22D3 expression by TNF. Finally, formoterol-enhanced 2×GRE reporter activity was also proportional to agonist efficacy and functionally reversed repression by TNF. As similar effects were apparent on glucocorticoid-induced gene expression, the most effective strategy to overcome glucocorticoid resistance in this model was addition of formoterol to high efficacy NR3C1 agonists.

Retroviral cDNA expression libraries allow the efficient introduction of complex cDNA libraries into virtually any mitotic cell type for screening based on gene function. The cDNA copy number per cell can be easily controlled by adjusting the multiplicity of infection, thus cell populations may be generated in which >90% of infected cells contain one to three cDNAs. We describe the isolation of two known oncogenes and one cell-surface receptor from a human Burkitt’s lymphoma (Daudi) cDNA library inserted into the hightiter retroviral vector pFB.

In this study, purified preparations of platelet protein disulfide isomerase (PDI), vitronectin, alpha-thrombin, and antithrombin (AT) were used to demonstrate that PDI catalyzes formation of vitronectin-thrombin-AT complexes. Complex formation requires reduced glutathione (GSH) and can be prevented by N-ethymaleimide, and the formed complex is dissociated by reducing agents such as mercaptoethanol. No vitronectin-thrombin complex formed in the absence of AT, indicating that the thrombin-AT complex is an obligate intermediate in the reaction. Under optimal conditions, the majority of the thrombin-AT is incorporated into the complex in 60 min. Thrombospondin-1, known to form disulfide-linked complexes with thrombin-AT [Milev, Y., and Essex, D. W. (1999) Arch. Biochem. Biophys. 361, 120-126], competes with vitronectin for thrombin-AT in the low-Ca(2+) environment that favors the active form of thrombospondin. The results presented here may also explain previous studies showing that vitronectin-thrombin-AT complexes form better in plasma (which contains PDI) than with purified proteins (where PDI was not used). We were able to purify a PDI from plasma that was immunologically identical to the platelet enzyme. We used the scrambled RNase assay to show that added purified PDI can function in a plasma environment. Complex formation in plasma was inhibited by inhibitors of PDI. PDI was released from the platelet surface in a soluble form at high pH (around the physiologic range), suggesting a source of the plasma PDI. In summary, these studies indicate that PDI functions to form disulfide-linked complexes of vitronectin with thrombin-AT.

Breast cancer is a leading cause of death among women. Understanding breast cancer at the molecular level is imperative for finding more effective approaches to successfully treat these patients. Microtubule inhibitors are among the most frequently used agents for breast cancer treatment, with proven efficacy in both localized and metastatic disease. Paclitaxel (Taxol) is a member of the taxane class of anti-neoplastic microtubule damaging agents and exhibits activity against a wide range of human malignancies including breast cancer. Paclitaxel stabilizes microtubules, resulting in G2/M cell cycle arrest, and continuous treatment with paclitaxel ultimately leads to cell death. However, the precise mechanisms of how this mitotic arrest triggers cell death are still unclear. When cells undergo paclitaxel-induced cell death, the BCL-2 family-dependent mitochondrial apoptotic pathway is activated. Previous studies indicate that a BH3-only protein BIM (BCL-2 Interacting Mediator of cell death) plays a role in paclitaxel-induced apoptosis. We show here that BIM is dispensable in apoptosis with paclitaxel treatment using bim−/− MEFs (mouse embryonic fibroblasts), the bim−/− mouse breast tumor model, and shRNA-mediated down-regulation of BIM in human breast cancer cells. In contrast, both bak−/− MEFs and human breast cancer cells in which BAK was down-regulated by shRNA were more resistant to paclitaxel. In human breast cancer cells, paclitaxel treatment resulted in MCL-1 degradation which was prevented by a proteasome inhibitor, MG132. A cdk inhibitor, roscovitine, blocked paclitaxel-induced MCL-1 degradation and apoptosis, suggesting that cdk activation at mitotic arrest could induce MCL-1 phosphorylation and subsequent degradation in a proteasome-dependent manner. BAK was associated with MCL-1 in untreated cells and became activated in concert with loss of MCL-1 expression and its release from the complex. Our data suggest that BAK is the mediator of paclitaxel-induced apoptosis and could be an alternative target for overcoming paclitaxel resistance. Citation Format: Anna V. Miller, Mark A. Hicks, Amanda C. Richardson, Jolene J. Windle, Hisashi Harada. Paclitaxel-induced apoptosis is BAK-dependent, but BAX and BIM-independent in breast tumor. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5579. doi:10.1158/1538-7445.AM2013-5579

Glucocorticoids (GCs) are common components of many chemotherapeutic regimens for lymphoid malignancies. GC-induced apoptosis involves an intrinsic mitochondria-dependent pathway. BIM (BCL-2-interacting mediator of cell death), a BCL-2 homology 3-only pro-apoptotic protein, is upregulated by dexamethasone (Dex) treatment in acute lymphoblastic leukemia cells and has an essential role in Dex-induced apoptosis. It has been indicated that Dex-induced BIM is regulated mainly by transcription, however, the molecular mechanisms including responsible transcription factors are unclear. In this study, we found that Dex treatment induced transcription factor Runx2 and c-Jun in parallel with BIM induction. Dex-induced BIM and apoptosis were decreased in cells harboring dominant-negative c-Jun and were increased in cells with c-Jun overexpression. Cells harboring short hairpin RNA for Runx2 also decreased BIM induction and apoptosis. On the Bim promoter, c-Jun bound to and activated the AP-1-binding site at about -2.7 kb from the transcription start site. Treatment with RU486, a GC receptor antagonist, blocked Dex-induced Runx2, c-Jun and BIM induction, as well as apoptosis. Furthermore, pretreatment with SB203580, a p38-mitogen-activated protein kinase (MAPK) inhibitor, decreased Dex-induced Runx2, c-Jun and BIM, suggesting that p38-MAPK activation is upstream of the induction of these molecules. In conclusion, we identified the critical signaling pathway for GC-induced apoptosis, and targeting these molecules may be an alternative approach to overcome GC-resistance in leukemia treatment.

β 1 integrin signaling has been implicated in the progression and metastasis of various cancers and has been shown to facilitate resistance to radiation therapy. Our laboratory showed that extracellular matrix (ECM) signaling via β1 integrin downregulates homologous recombination (HR), as well as ionizing radiation (IR) induced foci formation of γ-H2AX, RAD51, and MRE11 in single non-dividing cells of a non-tumorigenic human breast epithelial cell line. When the cells were allowed to form junctions, ECM had the opposite effect on repair. Mouse mammary epithelial cells in primary culture behaved as junctioned human breast epithelial cells, upregulating HR and IR induced γ-H2AX foci formation. These results suggested the importance of the tissue microenvironment including cell-cell junctions. Here we hypothesized that β1 integrin-mediated repair depends on the context including homotypic and heterotypic cellular interactions. To test this hypothesis, we studied the effect of β1 integrin in the mouse mammary gland in vivo on DNA repair relevant outcomes. For determining the β1 integrin effect on foci kinetics, mice were intraperitonially injected with the function-blocking antibody Ha2/5 or control IgG. 24 hrs later, the mice were subjected to 6 Gy IR and the level of γ-H2AX foci formation determined by counting Z-stacks of confocal microscopy images. We found that blocking the β1 integrin receptor significantly decreased γ-H2AX foci formation at 15 min, 1 hr, and 2 hrs post IR. These time points correlated with both the formation and disappearance kinetics of the foci. Both the β1 blocked and control mammary glands resolved all foci successfully by 4 hrs, suggesting that overall repair was not attenuated by systemic β1 integrin blocking. We have also ablated the ITGB1 gene using the Cre/loxP recombination system. Cre endonuclease was delivered by up-the-teat injections into 8-12 week old pre-pubertal mice, epithelial organoids were isolated, β1 integrin and Cre endonuclease expression are determined by immunocytochemistry. Cre recombinase was successfully delivered to the ductal epithelial cells by up-the-teat viral injection, and resulted in reduced β1 integrin expression in ∼80% of the organoids isolated from injected mice. In addition MMTV/Cre and ITGB1 floxed mice were crossed to successfully excise the β1 integrin gene and reduce protein expression in the mammary glands of mice aged 10-13 weeks. Experiments are in progress to determine the effects of local and complete β1 integrin gene ablation on IR induced repair foci kinetics. These observations provide the proof-of-principle that ECM has a normal function in maintaining DNA repair processes via β1 integrin signaling in the complex in vivo microenvironment of the mouse mammary gland as well as in cultured cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2472. doi:10.1158/1538-7445.AM2011-2472

In the airways of asthmatic patients, activated fibroblasts account for an excessive matrix production including proteoglycans (PGs). Transforming growth factor-beta (TGFbeta), metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play key roles in matrix turnover. It is unclear whether asthma therapy with combination of inhaled glucocorticoids and long-acting beta(2)-agonists affects metalloproteolytic equilibrium and by that counteracts airway fibrosis. The effects of the glucocorticoid, budesonide, and the long-acting beta(2)-agonist, formoterol, on the PG production and the activity of PGs' main regulators: MMP-3, MMP-9, MMP-2 and TIMP-1 were investigated in human lung fibroblasts (HFL-1) treated for 24h with TGFbeta1 (10 ng/ml) without/with budesonide (10(-9) to 10(-6)M) and/or formoterol (10(-11) to 10(-6)M). TGFbeta1 significantly increased production of PGs and TIMP-1, and the activity of MMP-3, MMP-9 and MMP-2. Concurrent budesonide/formoterol combination counteracted the enhanced: PG and TIMP-1 production, MMP-9 activity and MMP-9/TIMP-1 ratio, whereas MMP-2 and MMP-3 were not affected and so their ratios to TIMP-1 were significantly increased. Budesonide or formoterol alone achieved equal effects as budesonide/formoterol on MMP-9 and MMP-9/TIMP-1 ratio but had no effects on TIMP-1, MMP-2 or MMP-3. In the formoterol absence, higher budesonide concentrations were required to reduce the PG production, whereas formoterol alone had no effects. These results suggest that the budesonide/formoterol combination enhanced metalloproteolytic activity of human lung fibroblasts via a synergistic decrease of TIMP-1, and that this mechanism may be involved in the synergistic inhibition of the TGFbeta1-induced PG production. This implies that budesonide/formoterol combination therapy can counteract excessive matrix production and thus pathological airway fibrotic remodeling in asthma.