Efficacy and safety of levosalbutamol in patients with mild to moderate asthma compared with racemic salbutamol: results of a crossover placebo-controlled study

Aim. Effectiveness and safety of levosalbutamol metered dose inhaler (MDI) in comparison with placebo and salbutamol. Materials and methods. In this multicenter, randomized, placebo-controlled, 3-period crossover study, all asthma patients (n=91) received levosalbutamol (90 mcg), salbutamol (180 mcg), and placebo using standard MDI. Pulmonary function testing – forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) – was performed 45 and 15 minutes before and 5, 10, 15, 30, 60, 90, 120, 180, 240, 300 and 360 minutes after dosing. The primary efficacy endpoint was the baseline-corrected area under FEV1 curve from 0 to 6 hours (AUC(0–6h)). Secondary endpoints were the baseline adjusted FEV1 and FVC peak values, as well as the onset of drug action. Results. The FEV1 AUC0–6 hours analysis confirmed similar bronchodilatory levosalbutamol and salbutamol effect (p=0.595), significantly improved compared with placebo (p0.001). The peak values of FEV1 and FVC after levosalbutamol or salbutamol dosing were similar (p=0.643) and significantly higher compared with placebo group (p0.001). The active therapy effect was observed 5 minutes after dosing and throughout the entire observation period up to 6 hours, however, there was some tendency towards a longer duration of action of levosalbutamol compared to salbutamol. Levosalbutamol was well tolerated by patients; after levosalbutamol dosing twiсе fewer adverse reactions were observed compared to salbutamol. Conclusion. Levosalbutamol at a 90-mcg dose showed efficacy similar to that of salbutamol at a dose of 180 mcg, assosiated with a good safety profile

Metabolically active neutrophils represent a permissive niche for Mycobacterium tuberculosis

International audienceMycobacterium tuberculosis (Mtb)-infected neutrophils are often found in the airways of patients with active tuberculosis (TB), and excessive recruitment of neutrophils to the lung is linked to increased bacterial burden and aggravated pathology in TB. The basis for the permissiveness of neutrophils for Mtb and the ability to be pathogenic in TB has been elusive. Here, we identified metabolic and functional features of neutrophils that contribute to their permissiveness in Mtb infection. Using single-cell metabolic and transcriptional analyses, we found that neutrophils in the Mtb-infected lung displayed elevated mitochondrial metabolism, which was largely attributed to the induction of activated neutrophils with enhanced metabolic activities. The activated neutrophil subpopulation was also identified in the lung granulomas from Mtb-infected nonhuman primates. Functionally, activated neutrophils harbored more viable bacteria and displayed enhanced lipid uptake and accumulation. Surprisingly, we found that interferon-γ promoted the activation of lung neutrophils during Mtb infection. Lastly, perturbation of lipid uptake pathways selectively compromised Mtb survival in activated neutrophils. These findings suggest that neutrophil heterogeneity and metabolic diversity are key to their permissiveness for Mtb and that metabolic pathways in neutrophils represent potential host-directed therapeutics in TB

Matrix metalloproteinase inhibitors enhance the efficacy of frontline drugs against <i>Mycobacterium tuberculosis</i>

<div><p><i>Mycobacterium tuberculosis</i> (Mtb) remains a grave threat to world health with emerging drug resistant strains. One prominent feature of Mtb infection is the extensive reprogramming of host tissue at the site of infection. Here we report that inhibition of matrix metalloproteinase (MMP) activity by a panel of small molecule inhibitors enhances the <i>in vivo</i> potency of the frontline TB drugs isoniazid (INH) and rifampicin (RIF). Inhibition of MMP activity leads to an increase in pericyte-covered blood vessel numbers and appears to stabilize the integrity of the infected lung tissue. In treated mice, we observe an increased delivery and/or retention of frontline TB drugs in the infected lungs, resulting in enhanced drug efficacy. These findings indicate that targeting Mtb-induced host tissue remodeling can increase therapeutic efficacy and could enhance the effectiveness of current drug regimens.</p></div

Inhibition of MMP results in an increase in both collagen and mannose binding lectin (MBL) within the infected tissue.

<p><b>(A):</b> Hydroxyproline concentration in lung tissue from infected mice under different treatments (n = 5). Data represented mean ± SD. **: p < 0.01, ***: p < 0.001, One-way ANOVA with Šidák multiple comparison test. (<b>B):</b> MBL protein level from lung lysate of infected mice with different treatments (n = 5).</p

Other frontline TB drug (RIF) and other MMP inhibitors can induce synergistic effect to reduce Mtb burden.

<p><b>(A):</b> CFU count of lung tissue from Mtb-infected mice treated with Marimastat and RIF. Each dot represented one mouse (n = 4). Data represented mean. ***: p < 0.001, Two-tailed Unpaired Student <i>t</i> test with Welch-correction. <b>(B):</b> CFU count of lung tissue from Mtb-infected mice treated with other MMP inhibitors and INH. Each dot represented one mouse (n = 5). Data represented mean. ***: p < 0.001, One-way ANOVA with Šidák multiple comparison test.</p

MMP inhibitors facilitate INH killing of Mtb.

<p><b>(A):</b> Experimental setting of Marimastat’s effect in lung infection model (n = 5). (<b>B):</b> CFU count of 2 groups (PBS and Marimastat) at Day 14, and 4 groups (PBS, Marimastat, INH and Mariamstat+INH) at Day 28 post infection. Each dot represented one mouse (n = 5). Experiment was repeated 3 times with similar observation. Data showed results from one representative experiment. <b>(C):</b> H&E stain of the 4 groups (PBS, Marimastat, INH and Mariamstat+INH) at Day 28 infection (n = 5). Scale bar: 1mm. Arrow indicated consolidated region circled by black line. <b>(D):</b> Quantification of inflammatory region percentage within tissue of in all mice from different treatment groups (n = 5). Data represented mean ± SD. **: p < 0.01, One-way ANOVA with Šidák multiple comparison test.</p

Primer sequence of <i>Mmp-2</i> and <i>Mmp-9</i>.

<p>Primer sequence of <i>Mmp-2</i> and <i>Mmp-9</i>.</p

Delivery and/or retention of Evans blue dye or frontline TB drugs in infected animals treated with Marimastat.

<p>(<b>A</b>): Mtb infected mice treated with or without Marimastat were injected intravenously with Evans blue dye before euthanization. Retention of Evans blue dye within the lung of infected mice treated with or without Marimastat. Data represented mean ± SD. **: p < 0.01, Two-tailed Unpaired Student <i>t</i> test with Welch-correction. Experiment was repeated twice. (<b>B</b> and <b>C</b>): Mtb infected mice treated with or without Marimastat were injected intravenously with RIF and INH before euthanization. At indicated time points, lung and blood samples were collected for drug measurement. The concentration of RIF (<b>B</b>) and INH (<b>C</b>) in the lung were normalized by drug concentration in the plasma. Data represented mean ± SD. *: p < 0.05, ****: p < 0.0001, One-way ANOVA with Šidák multiple comparison test.</p

CD31 and α-SMA staining in the lung of infected mice treated with Marimastat.

<p><b>(A):</b> Mice infected with Mtb were treated with PBS (n = 5) or Marimastat (n = 5). Lung tissue from infected mice was stained for CD31 (upper panel) and α-SMA (lower panel). Both PBS and Marimastat groups had positive staining of CD31 and α-SMA. Scale bar: 80μm. (<b>B, C, D):</b> Quantification of CD31 positive blood vessel number (B), percentage of α-SMA positive staining (C), and α-SMA positive blood vessel number (D) in PBS or Marimastat treated mice (n = 5) 4-week post infection. Data represent mean ± SD. *: p < 0.05, **: p < 0.01, Two-tailed Unpaired Student <i>t</i> test with Welch-correction. <b>(E, F):</b> Quantification of percentage of α-SMA positive staining (E), and α-SMA positive blood vessel number (F) in consolidated area (granuloma like area) and surrounding normal tissue from PBS or Marimastat treated mice (n = 5) 4-week post infection. Data represented mean ± SD. *: p < 0.05, **: p < 0.01, One-way ANOVA with Šidák multiple comparison test.</p