The selective phosphodiesterase 4 inhibitor roflumilast and phosphodiesterase 3/4 inhibitor pumafentrine reduce clinical score and TNF expression in experimental colitis in mice.

The specific inhibition of phosphodiesterase (PDE)4 and dual inhibition of PDE3 and PDE4 has been shown to decrease inflammation by suppression of pro-inflammatory cytokine synthesis. We examined the effect of roflumilast, a selective PDE4 inhibitor marketed for severe COPD, and the investigational compound pumafentrine, a dual PDE3/PDE4 inhibitor, in the preventive dextran sodium sulfate (DSS)-induced colitis model. The clinical score, colon length, histologic score and colon cytokine production from mice with DSS-induced colitis (3.5% DSS in drinking water for 11 days) receiving either roflumilast (1 or 5 mg/kg body weight/d p.o.) or pumafentrine (1.5 or 5 mg/kg/d p.o.) were determined and compared to vehicle treated control mice. In the pumafentrine-treated animals, splenocytes were analyzed for interferon-γ (IFNγ) production and CD69 expression. Roflumilast treatment resulted in dose-dependent improvements of clinical score (weight loss, stool consistency and bleeding), colon length, and local tumor necrosis factor-α (TNFα) production in the colonic tissue. These findings, however, were not associated with an improvement of the histologic score. Administration of pumafentrine at 5 mg/kg/d alleviated the clinical score, the colon length shortening, and local TNFα production. In vitro stimulated splenocytes after in vivo treatment with pumafentrine showed a significantly lower state of activation and production of IFNγ compared to no treatment in vivo. These series of experiments document the ameliorating effect of roflumilast and pumafentrine on the clinical score and TNF expression of experimental colitis in mice

Phosphodiesterase type 4 expression and anti-proliferative effects in human pulmonary artery smooth muscle cells

BACKGROUND: Pulmonary arterial hypertension is a proliferative vascular disease, characterized by aberrant regulation of smooth muscle cell proliferation and apoptosis in distal pulmonary arteries. Prostacyclin (PGI(2)) analogues have anti-proliferative effects on distal human pulmonary artery smooth muscle cells (PASMCs), which are dependent on intracellular cAMP stimulation. We therefore sought to investigate the involvement of the main cAMP-specific enzymes, phosphodiesterase type 4 (PDE4), responsible for cAMP hydrolysis. METHODS: Distal human PASMCs were derived from pulmonary arteries by explant culture (n = 14, passage 3–12). Responses to platelet-derived growth factor-BB (5–10 ng/ml), serum, PGI(2 )analogues (cicaprost, iloprost) and PDE4 inhibitors (roflumilast, rolipram, cilomilast) were determined by measuring cAMP phosphodiesterase activity, intracellular cAMP levels, DNA synthesis, apoptosis (as measured by DNA fragmentation and nuclear condensation) and matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) production. RESULTS: Expression of all four PDE4A-D genes was detected in PASMC isolates. PDE4 contributed to the main proportion (35.9 ± 2.3%, n = 5) of cAMP-specific hydrolytic activity demonstrated in PASMCs, compared to PDE3 (21.5 ± 2.5%), PDE2 (15.8 ± 3.4%) or PDE1 activity (14.5 ± 4.2%). Intracellular cAMP levels were increased by PGI(2 )analogues and further elevated in cells co-treated with roflumilast, rolipram and cilomilast. DNA synthesis was attenuated by 1 μM roflumilast (49 ± 6% inhibition), rolipram (37 ± 6%) and cilomilast (30 ± 4%) and, in the presence of 5 nM cicaprost, these compounds exhibited EC(50 )values of 4.4 (2.6–6.1) nM (Mean and 95% confidence interval), 59 (36–83) nM and 97 (66–130) nM respectively. Roflumilast attenuated cell proliferation and gelatinase (MMP-2 and MMP-9) production and promoted the anti-proliferative effects of PGI(2 )analogues. The cAMP activators iloprost and forskolin also induced apoptosis, whereas roflumilast had no significant effect. CONCLUSION: PDE4 enzymes are expressed in distal human PASMCs and the effects of cAMP-stimulating agents on DNA synthesis, proliferation and MMP production is dependent, at least in part, on PDE4 activity. PDE4 inhibition may provide greater control of cAMP-mediated anti-proliferative effects in human PASMCs and therefore could prove useful as an additional therapy for pulmonary arterial hypertension

Source patterns of potentially toxic elements (PTEs) and mining activity contamination level in soils of Taltal city (northern Chile)

Mining activities are among the main sources of potentially toxic elements (PTEs) in the environment which constitute a real concern worldwide, especially in developing countries. These activities have been carried out for more than a century in Chile, South America, where, as evidence of incorrect waste disposal practices, several abandoned mining waste deposits were left behind. This study aimed to understand multi-elements geochemistry, source patterns and mobility of PTEs in soils of the Taltal urban area (northern Chile). Topsoil samples (n = 125) were collected in the urban area of Taltal city (6 km2) where physicochemical properties (redox potential, electric conductivity and pH) as well as chemical concentrations for 35 elements were determined by inductively coupled plasma optical emission spectrometer. Data were treated following a robust workflow, which included factor analysis (based on ilr-transformed data), a new robust compositional contamination index (RCCI), and fractal/multi-fractal interpolation in GIS environment. This approach allowed to generate significant elemental associations, identifying pool of elements related either to the geological background, pedogenic processes accompanying soil formation or to anthropogenic activities. In particular, the study eventually focused on a pool of 6 PTEs (As, Cd, Cr, Cu, Pb, and Zn), their spatial distribution in the Taltal city, and the potential sources and mechanisms controlling their concentrations. Results showed generally low baseline values of PTEs in most sites of the surveyed area. On a smaller number of sites, however, higher values concentrations of As, Cd, Cu, Zn and Pb were found. These corresponded to very high RCCI contamination level and were correlated to potential anthropogenic sources, such as the abandoned mining waste deposits in the north-eastern part of the Taltal city. This study highlighted new and significant insight on the contamination levels of Taltal city, and its links with anthropogenic activities. Further research is considered to be crucial to extend this assessment to the entire region. This would provide a comprehensive overview and vital information for the development of intervention limits and guide environmental legislation for these pollutants in Chilean soils

ROFLOMILAST IN MODERATE-TO-SEVERE CHRONIC OBSTRUCTIVE PULMONARY DISEASE TREATED WITH LONGACTING BRONCHODILATORS: TWO RANDOMISED CLINICAL TRIALS

Background Patients with chronic obstructive pulmonary disease (COPD) have few options for treatment. The effi cacy and safety of the phosphodiesterase-4 inhibitor rofl umilast have been investigated in studies of patients with moderate-to-severe COPD, but not in those concomitantly treated with longacting inhaled bronchodilators. The eff ect of rofl umilast on lung function in patients with COPD that is moderate to severe who are already being treated with salmeterol or tiotropium was investigated. Methods In two double-blind, multicentre studies done in an outpatient setting, after a 4-week run-in, patients older than 40 years with moderate-to-severe COPD were randomly assigned to oral rofl umilast 500 μg or placebo once a day for 24 weeks, in addition to salmeterol (M2-127 study) or tiotropium (M2-128 study). The primary endpoint was change in prebronchodilator forced expiratory volume in 1 s (FEV1). Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, number NCT00313209 for M2-127, and NCT00424268 for M2-128. Findings In the salmeterol plus rofl umilast trial, 466 patients were assigned to and treated with rofl umilast and 467 with placebo; in the tiotropium plus rofl umilast trial, 371 patients were assigned to and treated with rofl umilast and 372 with placebo. Compared with placebo, rofl umilast consistently improved mean prebronchodilator FEV1 by 49 mL (p<0·0001) in patients treated with salmeterol, and 80 mL (p<0·0001) in those treated with tiotropium. Similar improvement in postbronchodilator FEV1 was noted in both groups. Furthermore, rofl umilast had benefi cial eff ects on other lung function measurements and on selected patient-reported outcomes in both groups. Nausea, diarrhoea, weight loss, and, to a lesser extent, headache were more frequent in patients in the rofl umilast groups. These adverse events were associated with increased patient withdrawal. Interpretation Rofl umilast improves lung function in patients with COPD treated with salmeterol or tiotropium, and could become an important treatment for these patients

Roflumilast in moderate-to-severe chronic obstructive pulmonary disease treated with longacting bronchodilators: two randomised clinical trials.

Background Patients with chronic obstructive pulmonary disease (COPD) have few options for treatment. The effi cacy and safety of the phosphodiesterase-4 inhibitor rofl umilast have been investigated in studies of patients with moderate-to-severe COPD, but not in those concomitantly treated with longacting inhaled bronchodilators. The eff ect of rofl umilast on lung function in patients with COPD that is moderate to severe who are already being treated with salmeterol or tiotropium was investigated. Methods In two double-blind, multicentre studies done in an outpatient setting, after a 4-week run-in, patients older than 40 years with moderate-to-severe COPD were randomly assigned to oral rofl umilast 500 μg or placebo once a day for 24 weeks, in addition to salmeterol (M2-127 study) or tiotropium (M2-128 study). The primary endpoint was change in prebronchodilator forced expiratory volume in 1 s (FEV1). Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, number NCT00313209 for M2-127, and NCT00424268 for M2-128. Findings In the salmeterol plus rofl umilast trial, 466 patients were assigned to and treated with rofl umilast and 467 with placebo; in the tiotropium plus rofl umilast trial, 371 patients were assigned to and treated with rofl umilast and 372 with placebo. Compared with placebo, rofl umilast consistently improved mean prebronchodilator FEV1 by 49 mL (p<0·0001) in patients treated with salmeterol, and 80 mL (p<0·0001) in those treated with tiotropium. Similar improvement in postbronchodilator FEV1 was noted in both groups. Furthermore, rofl umilast had benefi cial eff ects on other lung function measurements and on selected patient-reported outcomes in both groups. Nausea, diarrhoea, weight loss, and, to a lesser extent, headache were more frequent in patients in the rofl umilast groups. These adverse events were associated with increased patient withdrawal. Interpretation Rofl umilast improves lung function in patients with COPD treated with salmeterol or tiotropium, and could become an important treatment for these patients