Fetal Concentrations of Budesonide and Fluticasone Propionate: a Study in Mice.

The study goal was to evaluate the transplacental transfer of two corticosteroids, budesonide (BUD) and fluticasone propionate (FP), in pregnant mice and investigate whether P-glycoprotein (P-gp) might be involved in reducing BUD transplacental transfer. Pregnant mice (N = 18) received intravenously either low (104.9 µg/kg) or high (1049 µg/kg) dose of [3H]-BUD or a high dose of [3H]-FP (1590 µg/kg). In a separate experiment, pregnant mice (N = 12) received subcutaneously either the P-gp inhibitor zosuquidar (20 mg/kg) or vehicle, followed by an intravenous infusion of [3H]-BUD (104.9 µg/kg). Total and free (protein unbound) corticosteroid concentrations were determined in plasma, brain, fetus, placenta, kidney, and liver. The ratios of free BUD concentrations in fetus versus plasma K(fetus, plasma, u, u) 0.42 ± 0.17 (mean ± SD) for low-dose and 0.38 ± 0.18 for high-dose BUD were significantly different from K = 1 (P < 0.05), contrary to 0.87 ± 0.25 for FP, which was moreover significantly higher than that for matching high-dose BUD (P < 0.01). The BUD brain/plasma ratio was also significantly smaller than K = 1, while these ratios for other tissues were close to 1. In the presence of the P-gp inhibitor, K(fetus, plasma, u, u) for BUD (0.59 ± 0.16) was significantly increased over vehicle treatment (0.31 ± 0.10; P < 0.01). This is the first in vivo study demonstrating that transplacental transfer of BUD is significantly lower than FP's transfer and that placental P-gp may be involved in reducing the fetal exposure to BUD. The study provides a mechanistic rationale for BUD's use in pregnancy.

Glucocorticoid-driven transcriptomes in human airway epithelial cells: commonalities, differences and functional insight from cell lines and primary cells.

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.

Bacterial regulation of macrophage bacterial recognition receptors in COPD are differentially modified by budesonide and fluticasone propionate.

RATIONALE: Patients with COPD have an increased risk for community-acquired pneumonia, which is further increased by inhaled corticosteroids. OBJECTIVE: To assess effects of the corticosteroids, budesonide and fluticasone propionate, on macrophage bacterial responses in COPD. METHODS: Monocyte-derived macrophages (MDMs) generated from blood monocytes from 10 non-smoker controls (NoS), 20 smokers without COPD (Sm), and 40 subjects with moderate to severe COPD (21 ex-smokers (COPD-ES) and 19 current smokers (COPD-S)) were pre-treated with budesonide or fluticasone (10 nM-1 µM) and challenged with live non-typeable Haemophilus influenzae (NTHI) or Streptococcus pneumoniae (SP). Cell surface bacterial recognition receptor expression (flow cytometry) and cytokine release (bead array) were analyzed. RESULTS: NTHI and SP reduced bacterial recognition receptor expression on MDMs from COPD and Sm, but not NoS (except TLR4). SR-AI and MARCO were reduced by both NTHI and SP, whereas other receptors by either NTHI or SP. Among COPD subjects, COPD-ES demonstrated a greater number of reductions as compared to COPD-S. NTHI reduced SR-AI, MARCO, CD11b, CD35 and CD206 in COPD-ES while only SR-AI and CD11b in COPD-S. SP reduced SRA-1, CD1d, TLR2 and TLR4 in both COPD-ES and COPD-S, and reduced MARCO and CD93 only in COPD-ES. All receptors reduced in COPD by NTHI and most by SP, were also reduced in Sm. Budesonide counteracted the receptor reductions induced by both NTHI (CD206 p = 0.03, MARCO p = 0.08) and SP (SR-AI p = 0.02) in COPD-ES. Fluticasone counteracted only SP-induced reductions in TLR2 (p = 0.008 COPD-ES and p = 0.04 COPD-S) and TLR4 (p = 0.02 COPD-ES). Cytokine release was equivalently reduced by both corticosteroids. CONCLUSIONS: Reduction in macrophage bacterial recognition receptors during bacterial exposure could provide a mechanism for the increased pneumonia risk in COPD. Differential effects of budesonide and fluticasone propionate on macrophage bacterial recognition receptor expression may contribute to the higher pneumonia incidence reported with fluticasone propionate.

Long-Acting ß2-Adrenoceptor Agonists Enhance Glucocorticoid Receptor (GR)-Mediated Transcription by Gene-Specific Mechanisms Rather Than Generic Effects via GR.

In asthma, the clinical efficacy of inhaled corticosteroids (ICSs) is enhanced by long-acting ß2-adrenoceptor agonists (LABAs). ICSs, or more accurately, glucocorticoids, promote therapeutically relevant changes in gene expression, and, in primary human bronchial epithelial cells (pHBECs) and airway smooth muscle cells, this genomic effect can be enhanced by a LABA. Modeling this interaction in human bronchial airway epithelial BEAS-2B cells transfected with a 2× glucocorticoid response element (2×GRE)-driven luciferase reporter showed glucocorticoid-induced transcription to be enhanced 2- to 3-fold by LABA. This glucocorticoid receptor (GR; NR3C1)-dependent effect occurred rapidly, was insensitive to protein synthesis inhibition, and was maximal when glucocorticoid and LABA were added concurrently. The ability of LABA to enhance GR-mediated transcription was not associated with changes in GR expression, serine (Ser203, Ser211, Ser226) phosphorylation, ligand affinity, or nuclear translocation. Chromatin immunoprecipitation demonstrated that glucocorticoid-induced recruitment of GR to the integrated 2×GRE reporter and multiple gene loci, whose mRNAs were unaffected or enhanced by LABA, was also unchanged by LABA. Transcriptomic analysis revealed glucocorticoid-induced mRNAs were variably enhanced, unaffected, or repressed by LABA. Thus, events leading to GR binding at target genes are not the primary explanation for how LABAs modulate GR-mediated transcription. As many glucocorticoid-induced genes are independently induced by LABA, gene-specific control by GR- and LABA-activated transcription factors may explain these observations. Because LABAs promote similar effects in pHBECs, therapeutic relevance is likely. These data illustrate the need to understand gene function(s), and the mechanisms leading to gene-specific induction, if existing ICS/LABA combination therapies are to be improved.

Scientific rationale for the possible inhaled corticosteroid intraclass difference in the risk of pneumonia in COPD.

Inhaled corticosteroids (ICSs) treatment combined with long-acting ß2-adrenoceptor agonists (LABAs) reduces the risk of exacerbations in COPD, but the use of ICSs is associated with increased incidence of pneumonia. There are indications that this association is stronger for fluticasone propionate than for budesonide. We have examined systematic reviews assessing the risk of pneumonia associated with fluticasone propionate and budesonide COPD therapy. Compared with placebo or LABAs, we found that fluticasone propionate was associated with 43%-78% increased risk of pneumonia, while only slightly increased risk or no risk was found for budesonide. We have evaluated conceivable mechanisms which may explain this difference and suggest that the higher pneumonia risk with fluticasone propionate treatment is caused by greater and more protracted immunosuppressive effects locally in the airways/lungs. These effects are due to the much slower dissolution of fluticasone propionate particles in airway luminal fluid, resulting in a slower uptake into the airway tissue and a much longer presence of fluticasone propionate in airway epithelial lining fluid.

Protein tyrosine phosphatase PTP-RR regulates corticosteroid sensitivity.

BACKGROUND: We have recently reported that protein phosphate 2A (PP2A) inactivation resulted in increased phosphorylation of the mitogen-activated protein kinase (MAPK) c-Jun N-terminal kinase 1 (JNK1) and glucocorticoid receptors (GR) at Ser(226), thereby reducing GR nuclear translocation and causing corticosteroid insensitivity in severe asthmatics. Protein tyrosine phosphatases (PTPs) are also known to be critically involved in the regulation of MAPKs, such as JNK and therefore potentially associated with GR function. The aim of study was to elucidate the involvement of MAPK-PTPs (PTP-RR, PTP-N5 and PTP-N7), which can dephosphorylate MAPKs, in the regulation of corticosteroid sensitivity. METHODS: Corticosteroid sensitivity, GR nuclear translocation, phosphorylation levels of GR-Ser(226), JNK1 and PP2A catalytic subunit (PP2AC)-Tyr(307) and protein expression levels and activities of PTP-RR and PP2AC were evaluated in U937 cells and/or peripheral blood mononuclear cells (PBMCs). Knock-down effects of MAPK-PTPs using siRNA were also evaluated. RESULTS: Knock-down of PTP-RR, but not of PTP-N5 or PTP-N7 impaired corticosteroid sensitivity, induced GR-Ser(226) phosphorylation and reduced GR nuclear translocation. Under IL-2/IL-4-induced corticosteroid insensitivity, PTP-RR expression, activity and associations with JNK1 and GR were reduced but PTP-RR activity was restored by formoterol. Also in PBMCs from severe asthmatic patients, PTP-RR and JNK1 expression were reduced and GR-Ser(226) phosphorylation increased. Furthermore, PTP-RR was associated with PP2A. PTP-RR reduction enhanced PP2AC-Tyr(307) phosphorylation leading to impairment of PP2A expression and activity. CONCLUSIONS: We demonstrated that with corticosteroid insensitivity PTP-RR fails to reduce phosphorylation of JNK1 and GR-Ser(226), resulting in down-regulation of GR nuclear translocation. Reduced PTP-RR may represent a novel cause of corticosteroid insensitivity in severe asthmatics.

An inhaled dose of budesonide induces genes involved in transcription and signaling in the human airways: enhancement of anti- and proinflammatory effector genes.

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.

Cytokine-induced loss of glucocorticoid function: effect of kinase inhibitors, long-acting ß(2)-adrenoceptor [corrected] agonist and glucocorticoid receptor ligands.

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-1ß 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.

Budesonide and formoterol effects on rhinovirus replication and epithelial cell cytokine responses.

BACKGROUND: Combination therapy with budesonide and formoterol reduces exacerbations of asthma, which are closely associated with human rhinovirus (RV) infections in both children and adults. These data suggest that budesonide and formoterol inhibit virus-induced inflammatory responses of airway epithelial cells. METHODS: To test this hypothesis, bronchial epithelial (BE) cells were obtained from airway brushings of 8 subjects with moderate-to-severe allergic asthma and 9 with neither asthma nor respiratory allergies. Cultured BE cells were incubated for 24 hours with budesonide (1.77 µM), formoterol (0.1 µM), both, or neither, and then inoculated with RV-16 (5×10(6) plaque forming units [PFU]/mL). After 24 hours, viral replication (RV RNA), cytokine secretion (CXCL8, CXCL10, TNFa, IFN-ß, IL-28) and mRNA expression (CXCL8, CXCL10, TNF, IFNB1, IL-28) were analyzed. RESULTS: RV infection induced CXCL10 protein secretion and IFNB1 and IL28 mRNA expression. Drug treatments significantly inhibited secretion of CXCL10 in mock-infected, but not RV-infected, BE cells, and inhibited secretion of TNFa under both conditions. Neither budesonide nor formoterol, alone or in combination, significantly affected viral replication, nor did they inhibit RV-induced upregulation of IFNB1 and IL28 mRNA. Overall, RV replication was positively related to CXCL10 secretion and induction of IFNB1 and IL28 mRNA, but the positive relationship between RV RNA and CXCL10 secretion was stronger in normal subjects than in subjects with asthma. CONCLUSIONS: Budesonide and formoterol can inhibit BE cell inflammatory responses in vitro without interfering with viral replication or production of interferons. These effects could potentially contribute to beneficial effects of budesonide/formoterol combination therapy in preventing RV-induced asthma exacerbations.

Anti-inflammatory effects of budesonide in human lung fibroblast are independent of histone deacetylase 2.

OBJECTIVE AND DESIGN: Reduced expression of histone deacetylase 2 (HDAC2) in alveolar macrophages and epithelial cells may account for reduced response of chronic obstructive pulmonary disease (COPD) patients to glucocorticoids. HDAC2 expression and its role in mediating glucocorticoid effects on fibroblast functions, however, has not been fully studied. This study was designed to investigate whether HDAC2 mediates glucocorticoid effects on release of inflammatory cytokines and matrix metalloproteinases (MMPs) from human lung fibroblasts. METHODS: Human lung fibroblasts (HFL-1 cells) were stimulated with interleukin (IL)-1 ß plus tumor necrosis factor (TNF)-α in the presence or absence of the glucocorticoid budesonide. Cytokines (IL-6 and IL-8) were quantified by enzyme linked immunosorbent assay (ELISA) and MMPs (MMP-1 and MMP-3) by immunoblotting in culture medium. The role of HDAC2 was investigated using a pharmacologic inhibitor as well as a small interfering ribonucleic acid (siRNA) targeting HDAC2. RESULTS: We have demonstrated that budesonide concentration-dependently (10(-10)-10(-7) M) inhibited IL-6, IL-8, MMP-1, and MMP-3 release by HFL-1 cells in response to IL-1ß plus TNF-α. While an HDAC inhibitor significantly blocked the inhibitory effect of budesonide on human bronchial epithelial cells (HBECs) and monocytes (THP-1 cells), it did not block the inhibitory effect of budesonide on release of cytokines and MMPs from HFL-1 cells. Similarly, an HDAC2-siRNA blocked budesonide inhibition of cytokine release in HBECs, but it did not block the inhibitory effect of budesonide on HFL-1 cytokine and MMP release. Furthermore, budesonide significantly blocked release of cytokines and MMPs to a similar degree in normal and COPD lung fibroblasts as well as in HFL-1 cells exposed or not exposed to cigarette smoke extract. CONCLUSION: These findings suggest that, in contrast to airway epithelial cells and monocytes/macrophages, HDAC2 is not required for budesonide to inhibit MMP and cytokine release by lung fibroblasts and this inhibitory pathway appears to be intact in cultured fibroblasts from COPD patients. These results also suggest that budesonide has the potential to modulate fibroblast-mediated tissue remodeling following airway inflammation in COPD, which is mediated via an HDAC2 independent pathway.

Effect of budesonide on fibroblast-mediated collagen gel contraction and degradation.

BACKGROUND: The balance between production and degradation of extracellular matrix is crucial in maintaining normal tissue structure. This study was designed to investigate the effect of budesonide on fibroblast-mediated tissue repair and remodeling. METHODS: Using human fetal lung fibroblasts in a three-dimensional collagen gel culture system, we investigated the effect of budesonide (1-1000 nM) on collagen gel contraction and degradation in the presence or absence of Inflammatory cytokines (interleukin-1ß and tumor necrosis factor α; 5 ng/mL each) and, in order to activate latent proteases, serine protease trypsin 0.25 µg/mL. The effects of budesonide on metalloproteinase production and activation were also investigated. RESULTS: Inflammatory cytokines significantly inhibited collagen gel contraction mediated by lung fibroblasts. Budesonide counteracted the effect of cytokines in a concentration-dependent manner (to 50%, P < 0.01). Budesonide 100 nM almost completely inhibited the release and mRNA expression of metalloproteinase-1, metalloproteinase-3, and metalloproteinase-9 induced by the cytokines (P< 0.05). Exposure to the cytokines plus trypsin increased collagen degradation and conversion of the metalloproteinases to lower molecular weight forms corresponding to their active forms. Budesonide blocked both enhanced collagen degradation (P< 0.01) and suppressed trypsin-mediated conversion of cytokine-induced metalloproteinase-9 and metalloproteinase-3 to lower molecular weight forms. Similar effects were observed with dexamethasone 1 µM, suggesting a class effect. CONCLUSION: These findings demonstrate that budesonide directly modulates contraction of collagen gels and can decrease collagen degradation under Inflammatory conditions. The mechanism of this effect is through suppressing gene expression, release, and activation of metalloproteinases. By modulating the release and activity of metalloproteinases, inhaled budesonide may be able to modify airway tissue repair and remodeling.

Modulation of transcriptional responses by poly(I:C) and human rhinovirus: effect of long-acting ß2-adrenoceptor agonists.

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 ß2-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 ß2-adrenoceptor agonists. These data show how human rhinovirus may attenuate glucocorticoid-induced transcription to reduce anti-inflammatory activity. However, addition of long-acting ß2-adrenoceptor agonist to the glucocorticoid functionally restored this response and shows how glucocorticoid plus long-acting ß2-adrenoceptor agonist combinations may prove beneficial during virus-induced exacerbations of asthma.

Tissue accumulation kinetics of ciclesonide-active metabolite and budesonide in mice.

Inhaled corticosteroids (ICS) are mainstay treatment of asthma and chronic obstructive pulmonary disease. However, highly lipophilic ICS accumulate in systemic tissues, which may lead to adverse systemic effects. The accumulation of a new, highly lipophilic ICS, ciclesonide and its active metabolite (des-CIC) has not yet been reported. Here, we have compared tissue accumulation of des-CIC and an ICS of a moderate lipophilicity, budesonide (BUD), after 14 days of once-daily treatment in mice. Single, three or 14 daily doses of [(3) H]-des-CIC or [(3) H]-BUD were administered subcutaneously to male CD1 albino mice, which were killed at 4 hr, 24 hr or 5 days after the last dose. Distribution of tissue concentration of radioactivity was studied by quantitative whole-body autoradiography. Pattern of radioactivity distribution across most tissues was similar for both corticosteroids after a single as well as after repeated dosing. However, tissue concentration of radioactivity differed between des-CIC and BUD. After a single dose, concentrations of radioactivity for both corticosteroids were low for most tissues but increased over 14 days of daily dosing. The tissue radioactivity of des-CIC at 24 hr and 5 days after the 14th dose was 2-3 times higher than that of BUD in majority of tissues. Tissue accumulation, assessed as concentration of tissue radioactivity 5 days after the 14th versus 3rd dose, showed an average ratio of 5.2 for des-CIC and 2.7 for BUD (p < 0.0001). In conclusion, des-CIC accumulated significantly more than BUD. Systemic accumulation may lead to increased risk of adverse systemic side effects during long-term therapy.

Pharmacological modulation of the bradykinin-induced differentiation of human lung fibroblasts: effects of budesonide and formoterol.

OBJECTIVE: 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 ß2-agonist, formoterol (FM), either alone or in combination, modified BK-induced lung fibroblast differentiation, and affected the BK-activated intracellular signaling pathways. METHODS: 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 Ca²âº concentration ([Ca²âº]i), and p65 nuclear factor kappa B translocation were evaluated. RESULTS: 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 [Ca²âº]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. CONCLUSION: 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.

Altered lung function relates to inflammation in an acute LPS mouse model.

Preclinical in vivo models of lipopolysaccharide (LPS) -induced acute lung injury are commonly used to recapitulate pathophysiological features of chronic obstructive pulmonary disease and acute exacerbations. The LPS-induced lung inflammation is well described; however, whether the inflammatory response relates temporally to specific alterations in lung function has not been elucidated. We have investigated the effects of acute LPS inhalation in mice up to 96 h post LPS. Quantitation of inflammatory cells and inflammatory mediators in bronchoalveolar lavage fluid and non-invasive and invasive lung function measurements were performed at corresponding time points. The inhibitory effect of the glucocorticoid, budesonide, on LPS-induced lung inflammation and lung function was determined. LPS inhalation induced distinct histopathological changes, and infiltration of inflammatory cells to the lungs peaked at 48 h. At this time point, significantly increased inflammatory mediators and significantly altered lung capacity and mechanics parameters were observed. Budesonide given per os prevented the LPS-induced lung inflammation and lung dysfunction. These results demonstrate a temporal relationship between the peak of inflammatory cell influx and significant impairment of lung function, suggestive of a causative role of inflammation. These results allow better understanding of the functional consequences of lung inflammation in respiratory diseases.

Lung epithelial-C/EBPß contributes to LPS-induced inflammation and its suppression by formoterol.

The inflammatory processes associated with pulmonary disorders remains incompletely understood. CCAAT/enhancer-binding protein (C/EBP)ß is implicated in inflammatory lung disorders as well as in ß(2)-adrenoceptor signaling. We hypothesized that C/EBPß 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 ß(2)-agonists (LABAs) and glucocorticoids (GCs). To investigate this, mice with a lung epithelial-specific deletion of C/EBPß (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 ß(2)-adrenoceptor dependent manner. Thus, C/EBPß in the lung epithelium contributes to LPS-induced CXCL1 expression and airway neutrophilia as well as to the suppressive effects of formoterol. Reduced C/EBPß activity, observed in smokers with chronic obstructive pulmonary disease, may impair the responsiveness to LABAs when used without GCs.

Increased corticosteroid sensitivity by a long acting ß2 agonist formoterol via ß2 adrenoceptor independent protein phosphatase 2A activation.

Long-acting ß2-adrenoceptor agonists (LABAs) are reported to enhance anti-inflammatory effects of corticosteroids in vitro and in vivo, although the molecular mechanisms have not yet been elucidated. We investigated the role of serine/threonine protein phosphatase 2A (PP2A) on regulation of corticosteroid sensitivity via inhibition of glucocorticoid receptor (GR) phosphorylation as the target of formoterol, an LABA. Corticosteroid sensitivity was determined as IC50 to dexamethasone (Dex) on TNFα-induced IL-8 release in a U937 monocytic cell line (Dex-IC50). Phosphorylation levels of GR-Ser226 and c-Jun N-terminal kinase (JNK) were determined by western-blotting. Phosphatase activity of immunopurified PP2A was measured by fluorescence-based assay. Exposure to IL-2/IL-4 for 48 h decreased Dex sensitivity with a concomitant increase of GR phosphorylation at Ser226 with JNK1 activation. Formoterol restored Dex sensitivity by inhibiting phosphorylation of GR-Ser226 and JNK1. PP2A inhibition by okadaic acid, a phosphatase inhibitor, abrogated formoterol-mediated effects. In addition, formoterol enhanced PP2A activity in intact or IL-2/IL-4 treated U937 cells and human peripheral blood mononuclear cells. In addition, PP2A activation by formoterol was not antagonized by ICI-118551, and formoterol could activate PP2A directly in cell free system. Taken together, formoterol increases corticosteroid sensitivity via activation of PP2A in receptor independent manner, explaining its benefits as add-on therapy for the treatment of corticosteroid-insensitive diseases, such as severe asthma.

TGFß-induced matrix production by bronchial fibroblasts in asthma: budesonide and formoterol effects.

To investigate the mechanisms of enhanced airway deposition of subepithelial collagen in asthma and its sensitivity to drug therapy with combination of an inhaled glucocorticosteroid (GC) and a long-acting ß(2)-agonist (LABA), a cell model system involving bronchial fibroblasts derived from biopsies from patients with stable mild-to-moderate asthma has been used. To mimic unstable conditions and severe asthma, fibroblasts were stimulated ex vivo with TGFß1. Primary fibroblasts established from central bronchial biopsies from 8 asthmatic patients were incubated for 24 h with 0.4% serum or TGFß1 (10 ng/ml) with/without the GC budesonide (BUD; 10 nM) and/or the LABA formoterol (FORM; 0.1 nM). Procollagen peptide I (PICP), metalloproteinase (MMP)-1 and tissue inhibitor of MMPs (TIMP-1) were determined in culture media using ELISA while the activity of MMP-2, -3, -9 by zymography. Metabolically labeled proteoglycans, biglycan and decorin, associated with collagen fibrillation/deposition, were separated using chromatography and SDS-PAGE. The levels of PICP and biglycan were increased 2-fold by TGFß1 (p < 0.05). The BUD and FORM combination reduced the PICP increase by 58% (p < 0.01) and the biglycan by 36% (p < 0.05) while each drug alone had no effect. Decorin levels were reduced by TGFß1 in fibroblasts of most patients; BUD alone and BUD and FORM completely counteracted this decrease. MMPs and TIMP-1 were not affected by TGFß1 or the drugs. These results suggest that BUD and FORM combination therapy, without affecting metalloproteolytic balance, has a potential to counteract enhanced collagen production by bronchial fibroblasts in asthma and to normalize the production of small proteoglycans which may affect collagen fibrillation and deposition.

Relationship between matrix production by bronchial fibroblasts and lung function and AHR in asthma.

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 ≤ r ≤ 0.9) with MMP-2 and MMP-3 activity. A positive correlation (r = 0.75) was also found between proteoglycan production and TIMP-1. There was no correlation between MMP-9 activity and PICP or proteoglycan production. MMP-9 activity positively correlated with patients' FEV(1)% predicted (r = 0.97) and methacholine log PD(20) (r = 0.86), whereas negative associations (-0.6 ≤ r ≤ -0.7) were observed for MMP-2 and MMP-3. In stable mild-to-moderate asthma, increased procollagen I synthesis and activity of MMP-2 and MMP-3 in bronchial fibroblasts may negatively affect patients' lung function and AHR. In contrast, MMP-9 activity was not associated with procollagen or proteoglycan production, or worsening of patients' lung function and AHR. An enhanced production of procollagen I and proteoglycans might be a result of a negative feedback from their degradation by MMP-2 and MMP-3.