The 24-h lung-function profile of once-daily tiotropium and olodaterol fixed-dose combination in chronic obstructive pulmonary disease.

BACKGROUND: This study investigated the effects on 24-h lung function and lung volume of a once-daily fixed-dose combination (FDC) of the long-acting muscarinic antagonist tiotropium and the long-acting ß2-agonist olodaterol in patients with chronic obstructive pulmonary disease. METHODS: This was a randomised, double-blind, placebo-controlled, Phase III trial with an incomplete crossover design. Patients received four of the following six treatment options for 6 weeks each: placebo, olodaterol 5 µg, tiotropium 2.5 µg, tiotropium 5 µg, tiotropium + olodaterol FDC 2.5/5 µg and tiotropium + olodaterol FDC 5/5 µg, all delivered via the Respimat(®) inhaler. The primary end point was forced expiratory volume in 1 s (FEV1) area under the curve from 0 to 24 h (AUC0-24) response after 6 weeks of treatment; key secondary end points were FEV1 AUC from 0 to 12 h and AUC from 12 to 24 h, and further end points included lung-volume parameters measured using body plethysmography (subset of patients), measures of peak and trough FEV1, and incidence of adverse events. RESULTS: A significant improvement in FEV1 AUC0-24 response was observed with tiotropium + olodaterol 5/5 µg and 2.5/5 µg versus placebo and monotherapies after 6 weeks of treatment; mean response with tiotropium + olodaterol 5/5 µg versus placebo was 0.280 L (p < 0.0001). Differences to monotherapies with tiotropium + olodaterol 5/5 µg were 0.115 L versus olodaterol 5 µg, 0.127 L versus tiotropium 2.5 µg and 0.110 L versus tiotropium 5 µg (p < 0.0001 for all comparisons). Secondary end points supported these data. No safety concerns were identified. CONCLUSIONS: Overall, this study demonstrated improvements in lung function over 24 h with an FDC of tiotropium + olodaterol over tiotropium or olodaterol alone, with no observed difference in tolerability. ClinicalTrials.gov number: NCT01559116.

Safety and efficacy of fluticasone propionate/salmeterol hydrofluoroalkane 134a metered-dose-inhaler compared with fluticasone propionate/salmeterol diskus in patients with chronic obstructive pulmonary disease.

PURPOSE: To provide information on the efficacy and safety of Fluticasone Propionate/Salmeterol Hydrofluoroalkane 134a Metered-Dose-Inhaler 230/42mcg (FSC MDI) and its comparable dose of Fluticasone Propionate/Salmeterol DISKUS 250/50mcg (FSC DISKUS) in patients with COPD. METHODS: This multicenter, randomized, double-blind, 12 week study was designed to evaluate FSC MDI treatment responses as compared with FSC DISKUS. The primary comparison of interest was non-inferiority between the FSC MDI treatment group and the FSC DISKUS treatment group assessed in terms of 2-hour post-dose FEV(1) change from baseline at endpoint. The non-inferiority criterion bound was 75mL (lower confidence limit of -75mL). INCLUSION CRITERIA: Male or female aged ≥ 40, post-bronchodilator FEV(1) ≤ 70% predicted normal, FEV(1)/FVC ≤ 70% and ≥ 10 pack years smoking history. Adverse events were recorded by patients throughout the study on daily diary cards. Adverse events were collected in eCRFs at all clinic visits and during a final follow-up phone call. RESULTS: Patients (N=247) were randomized to FSC MDI (FEV(1)% 49.3 ± 12.3, FEV(1)/FVC 50.5 ± 10.0) and FSC DISKUS (FEV(1)% 48.4 ± 11.0, FEV(1)/FVC 50.3 ± 10.3). From an ANCOVA model the least squares (LS) mean difference (FSC MDI- FSC DISKUS) for the 2-hour post dose FEV(1) at endpoint was -2.0mL (95% CI -64mL, 59mL). Pre-dose FEV(1), FVC, PEF, and albuterol use were also similar between the two formulations. The most common adverse events (AE) during treatment were headache (8% and 6% of patients), nasopharyngitis (4% and 6%), cough (3% and 4%), and sinusitis (2% and 5%) for FSC MDI and FSC DISKUS, respectively. Pneumonia was recorded as an AE for 2 (2%) patients in the FSC DISKUS arm. CONCLUSION: This is the first study to demonstrate that FSC MDI has a similar efficacy and safety profile to FSC DISKUS in COPD patients.

Effects of D-myo-inositol 1-phosphate on the transfer function of phosphatidylinositol transfer protein alpha.

The lipid metabolite D-myo-inositol-1-phosphate is shown to increase the phospholipid transfer activity of phosphatidylinositol transfer protein alpha from liposomal and liver microsomal membranes. Dose-response curves indicated substantial enhancements of transfer in the low mM range that upon normalization were independent of membrane composition or the identity of the transferred phospholipid. The unnormalized effect is potentiated by anionic membrane surface charge and substantial membrane phosphatidylethanolamine content consistent with alterations of the protein's membrane binding affinity and alterations of surface electrostatic interactions as contributing factors.

L-alpha-glycerylphosphorylcholine inhibits the transfer function of phosphatidylinositol transfer protein alpha.

Phosphatidylinositol transfer protein alpha (PITP-alpha) is a bifunctional phospholipid transfer protein that is highly selective for phosphatidylinositol (PtdIns) and phosphatidylcholine (PtdCho). Polar lipid metabolites, including L-alpha-glycerylphosphorylcholine (GroPCho), increasingly have been linked to changes in cellular function and to disease. In this study, polar lipid metabolites of PtdIns and PtdCho were tested for their ability to influence PITP-alpha activity. GroPCho inhibited the ability of PITP-alpha to transfer PtdIns or PtdCho between liposomes. The IC(50) of both processes was dependent on membrane composition. D-myo-inositol 1-phosphate and glycerylphosphorylinositol modestly enhanced PITP-alpha-mediated phospholipid transfer. Choline, phosphorylcholine (PCho), CDP-choline, glyceryl-3-phosphate, myo-inositol and D-myo-inositol 1,4,5-trisphosphate had little effect. Membrane surface charge was a strong determinant of the GroPCho inhibition with the inhibition being greatest for highly anionic membranes. GroPCho was shown to enhance the binding of PITP-alpha to anionic vesicles. In membranes of low surface charge, phosphatidylethanolamine (PtdEtn) was a determinant enabling the GroPCho inhibition. Anionic charge and PtdEtn content appeared to increase the strength of PITP-alpha-membrane interactions. The GroPCho-enhanced PITP-alpha-membrane binding was sufficient to cause inhibition, but not sufficient to account for the extent of inhibition observed. Processes associated with strengthened PITP-alpha-membrane binding in the presence of GroPCho appeared to impair the phospholipid insertion/extraction process.

Structure of apo-phosphatidylinositol transfer protein alpha provides insight into membrane association.

Phosphatidylinositol transfer protein alpha (PITP alpha) is a ubiquitous and highly conserved protein in multicellular eukaryotes that catalyzes the exchange of phospholipids between membranes in vitro and participates in cellular phospholipid metabolism, signal transduction and vesicular trafficking in vivo. Here we report the three-dimensional crystal structure of a phospholipid-free mouse PITP alpha at 2.0 A resolution. The structure reveals an open conformation characterized by a channel running through the protein. The channel is created by opening the phospholipid-binding cavity on one side by displacement of the C-terminal region and a hydrophobic lipid exchange loop, and on the other side by flattening of the central beta-sheet. The relaxed conformation is stabilized at the proposed membrane association site by hydrophobic interactions with a crystallographically related molecule, creating an intimate dimer. The observed open conformer is consistent with a membrane-bound state of PITP and suggests a mechanism for membrane anchoring and the presentation of phosphatidylinositol to kinases and phospholipases after its extraction from the membrane. Coordinates have been deposited in the Protein Data Bank (accession No. 1KCM).

The Golgi localization of phosphatidylinositol transfer protein beta requires the protein kinase C-dependent phosphorylation of serine 262 and is essential for maintaining plasma membrane sphingomyelin levels.

Recombinant mouse phosphatidylinositol transfer protein (PI-TP)beta is a substrate for protein kinase C (PKC)-dependent phosphorylation in vitro. Based on site-directed mutagenesis and two-dimensional tryptic peptide mapping, Ser(262) was identified as the major site of phosphorylation and Ser(165) as a minor phosphorylation site. The phospholipid transfer activities of wild-type PI-TP beta and PI-TP beta(S262A) were identical, whereas PI-TP beta(S165A) was completely inactive. PKC-dependent phosphorylation of Ser(262) also had no effect on the transfer activity of PI-TP beta. To investigate the role of Ser(262) in the functioning of PI-TP beta, wtPI-TP beta and PI-TP beta(S262A) were overexpressed in NIH3T3 fibroblast cells. Two-dimensional PAGE analysis of cell lysates was used to separate PI-TP beta from its phosphorylated form. After Western blotting, wtPI-TP beta was found to be 85% phosphorylated, whereas PI-TP beta(S262A) was not phosphorylated. In the presence of the PKC inhibitor GF 109203X, the phosphorylated form of wtPI-TP beta was strongly reduced. Immunolocalization showed that wtPI-TP beta was predominantly associated with the Golgi membranes. In the presence of the PKC inhibitor, wtPI-TP beta was distributed throughout the cell similar to what was observed for PI-TP beta(S262A). In contrast to wtPI-TP beta overexpressors, cells overexpressing PI-TP beta(S262A) were unable to rapidly replenish sphingomyelin in the plasma membrane upon degradation by sphingomyelinase. This implies that PKC-dependent association with the Golgi complex is a prerequisite for PI-TP beta to express its effect on sphingomyelin metabolism.