SMAD Signaling in the Airways of Healthy Rhesus Macaques versus Rhesus Macaques with Asthma Highlights a Relationship Between Inflammation and Bone Morphogenetic Proteins

Bone morphogenetic protein (BMP) signaling is important for correct lung morphogenesis, and there is evidence of BMP signaling reactivation in lung diseases. However, little is known about BMP signaling patterns in healthy airway homeostasis and inflammatory airway disease and during epithelial repair. In this study, a rhesus macaque (Macaca mulatta) model of allergic airway disease was used to investigate BMP signaling throughout the airways in health, disease, and regeneration. Stereologic quantification of immunofluorescent images was used to determine the expression of BMP receptor (BMPR) Ia and phosphorylated SMAD (pSMAD) 1/5/8 in the airway epithelium. A pSMAD 1/5/8 expression gradient was found along the airways of healthy juvenile rhesus macaques (n = 3, P , 0.005). Membrane-localized BMPRIa expression was also present in the epithelium of the healthy animals. After exposure to house dust mite allergen and ozone, significant down-regulation of nuclear pSMAD 1/5/8 occurs in the epithelium. When the animals were provided with a recovery period in filtered air, proliferating cell nuclear antigen, pSMAD 1/5/8, and membrane-localized BMPRIa expression were significantly increased in the epithelium of conducting airways (P , 0.005). Furthermore, in the asthmatic airways, altered BMPRIa localization was evident. Because of the elevated eosinophil presence in these airways, we investigated the effect of eosinophil-derived proteins on BMPRIa trafficking in epithelial cells. Eosinophil-derived proteins (eosinophil-derived neurotoxin, eosinophil peroxidase, and major basic protein) induced transient nuclear translocation of membrane-bound BMPRIa. This work mapping SMAD signaling in the airways of nonhuman primates highlights a potential mechanistic relationship between inflammatory mediators and BMP signaling and provides evidence that basal expression of the BMP signaling pathway may be important for maintaining healthy airways

A Method to Assess Adherence in Inhaler Use through Analysis of Acoustic Recordings of Inhaler Events

<div><p>Rationale</p><p>Poor adherence to inhaler use can be due to poor temporal and/or technique adherence. Up until now there has been no way of reliably tracking both these factors in everyday inhaler use.</p><p>Objectives</p><p>This paper introduces a device developed to create time stamped acoustic recordings of an individual's inhaler use, in which empirical evidence of temporal and technique adherence in inhaler use can be monitored over time. The correlation between clinical outcomes and adherence, as determined by this device, was compared for temporal adherence alone and combined temporal and technique adherence.</p><p>Findings</p><p>The technology was validated by showing that the doses taken matched the number of audio recordings (r² = 0.94, p<0.01). To demonstrate that audio analysis of inhaler use gives objective information, in vitro studies were performed. These showed that acoustic profiles of inhalations correlated with the peak inspiratory flow rate (r² = 0.97, p<0.01), and that the acoustic energy of exhalations into the inhaler was related to the amount of drug removed. Despite training, 16% of participants exhaled into the mouthpiece after priming, in >20% of their inhaler events. Repeated training reduced this to 7% of participants (p = 0.03). When time of use was considered, there was no evidence of a relationship between adherence and changes in AQLQ (r² = 0.2) or PEFR (r² = 0.2). Combining time and technique the rate of adherence was related to changes in AQLQ (r² = 0.53, p = 0.01) and PEFR (r² = 0.29, p = 0.01).</p><p>Conclusions</p><p>This study presents a novel method to objectively assess how errors in both time and technique of inhaler use impact on clinical outcomes.</p><p>Trial Registration</p><p><a href="https://eudract.ema.europa.eu" target="_blank">EudraCT 2011-004149-42</a></p></div

Comparing Inhaler steps to INCA device Function.

<p>Comparing Inhaler steps to INCA device Function.</p

Baseline details of the original study cohort; BMI = Body Mass Index, AQLQ = Asthma Quality of Life Questionnaire, PEFR = Peak Expiratory Flow Rate.

<p>Baseline details of the original study cohort; BMI  =  Body Mass Index, AQLQ  =  Asthma Quality of Life Questionnaire, PEFR  =  Peak Expiratory Flow Rate.</p

A Bland Altman plot showing the relationship of the doses taken, recorded by the dose counter on the Diskus and the number of audio files logged on the metadata of the INCA device is shown in (A).

<p>In (B) the same data is displayed as a correlation of the doses taken to the number of audio recordings.</p

The audio recording device, attached to the Diskus inhaler is shown in (A).

<p>In (B) the amplitude of the audio associated with an inhaler being used is shown, in (C) the corresponding audio is shown in the frequency domain. From analysis of the audio the clear differences in the features of each of the steps is shown. After fully opening the device, which starts electronic recording, the first critical step is the lever movement to blister the drug. This step is characterized by a short burst of energy lasting approximately 20–30 ms with a high frequency content (∼2 kHz) preceded by a short burst of lower frequency noise (∼1 kHz). Prior studies have shown that there is a difference in spectral components in the frequency domain between inhalations and exhalations an exhalation has a sharp increase in amplitude that tapers off with time and the power of exhalation decreases exponentially from 2 kHz to 500 Hz while the spectral power for inhalations are higher and they have a low increase in amplitude compared to that of exhalations.¹⁸</p

Recorded average clinical measures over study period; AQLQ = Asthma Quality of Life Questionnaire, PEFR = Peak Expiratory Flow Rate.

<p>Recorded average clinical measures over study period; AQLQ  =  Asthma Quality of Life Questionnaire, PEFR  =  Peak Expiratory Flow Rate.</p

In (A) the rate of adherence by time of use for patients who improved by the minimum clinically important difference in AQLQ are shown in red and those who did not is shown, in black.

<p>Time of inhaler use did not relate to changes in clinical status. In (B) the adherence rate including the time and technique of use is shown. Those who had at least a minimum important clinically difference in AQLQ over the observation period are shown in blue, while those who did not are shown in green. There was a significant relationship between the rate of adherence and the outcomes in AQLQ when both time and technique were assessed. In (C) the rate of adherence by time of use for patients who changes in PEFR is shown, the red line is those who had a trend of improved PEFR and those who did not is shown, in blue. In (D) the adherence rate including the time and technique of use is shown, there was an association of the improvement in PEFR with increased inhaler use, blue and those who did not, green.</p

The amplitude and corresponding spectrogram of an individual with a weak inhalation is shown in (A).

<p>In (B) the amplitude and corresponding spectrogram of another individual with a strong inhalation is shown. In (C) the relationship of the amplitude of inhalation to peak inspiratory flow rate is shown, there is a strong relationship between these two variables, r² = 0.97. In (D) the relationship of amplitude of inhalation to drug removal is shown.</p