Loss of lysosomal membrane integrity results in leakage of lysosomal hydrolases to the cytosol which might harm cell function and induce cell death. Destabilization of lysosomes often precede apoptotic or necrotic cell death and occur during both physiological and pathological conditions. The weak base acridine orange readily enters cells and accumulates in the acidic environment of lysosomes. Vital staining with acridine orange is a well-proven technique to observe lysosomal destabilization using fluorescence microscopy and flow cytometry. These analyses are, however, time consuming and only adapted for discrete time points, which make them unsuitable for large-scale approaches. Therefore, we have developed a time-saving, high-throughput microplate reader-based method to follow destabilization of the lysosomal membrane in real-time using acridine orange. This protocol can easily be adopted for patient samples since the number of cells per sample is low and the time for analysis is short.

Purpose: Transforming growth factor (TGF)-β1 triggers epithelial–mesenchymal transition (EMT) through autophagy, which is partly driven by reactive oxygen species (ROS). The aim of this study was to determine whether leaking lysosomes and enhanced degradation of H-ferritin could be involved in EMT and whether it could be possible to prevent EMT by iron chelation targeting of the lysosome. Materials and methods: EMT, H-ferritin, and autophagy were evaluated in TGF-β1-stimulated A549 human lung epithelial cells cultured in vitro using Western blotting, with the additional morphological assessment of EMT. By using immunofluorescence and flow cytometry, lysosomes and ROS were assessed by acridine orange and 6-carboxy-2’,7’-dichlorodihydrofluorescein acetate assays, respectively. Results: TGF-β1-stimulated cells demonstrated a loss of H-ferritin, which was prevented by the antioxidant N-acetyl-L-cysteine (NAC) and inhibitors of lysosomal degradation. TGF-β1 stimulation generated ROS and autophagosome formation and led to EMT, which was further promoted by the additional ROS-generating cytokine, tumor necrosis factor-α. Lysosomes of TGF-β1-stimulated cells were sensitized to oxidants but also completely protected by lysosomal loading with dextran-bound deferoxamine (DFO). Autophagy and EMT were prevented by NAC, DFO, and inhibitors of autophagy and lysosomal degradation.
Conclusion: The findings of this study support the role of enhanced autophagic degradation of H-ferritin as a mechanism for increasing the vulnerability of lysosomes to iron-driven oxidant injury that triggers further autophagy during EMT. This study proposes that lysosomal leakage is a novel pathway of TGF-β1-induced EMT that may be prevented by iron-chelating drugs that target the lysosome.

Background: Common features among patients with more advanced chronic obstructive pulmonary disease (COPD) are systemic inflammation and a loss of both muscle mass and normal muscle composition. In the present study, we investigated COPD subjects to better understand how thigh muscle fat infiltration (MFI) and energy metabolism relate to each other and to clinical features of COPD with emphasis on systemic inflammation. Methods: Thirty-two Caucasians with stable COPD were investigated using questionnaires, lung function tests, blood analysis and magnetic resonance imaging (MRI) for analysis of body- and thigh muscle composition. Bioenergetics in the resting thigh muscle, expressed as the PCr/Pi ratio, were analysed using ³¹phosphorus magnetic resonance spectroscopy (³¹P-MRS). Results: Based on the combination of the MFI adjusted for sex (MFI_a) and the thigh fat-tissue free muscle volume, expressed as the deviation from the expected muscle volume of a matched virtual control group (FFMV_vcg), all COPD subjects displayed abnormally composed thigh muscles. Clinical features of increased COPD severity, including a decrease of blood oxygenation (r = − 0.44, p < 0.05) and FEV₁/FVC ratio, reflecting airway obstruction (r = − 0.53, p < 0.01) and an increase of COPD symptoms (r = 0.37, p < 0.05) and breathing frequency at rest (r = 0.41, p < 0.05), were all associated with a raise of the PCr/Pi ratio in the thigh muscle. Increased MFI_a of the thigh muscle correlated positively with markers of systemic inflammation (white blood cell count, r = 0.41, p < 0.05; fibrinogen, r = 0.44, p < 0.05), and negatively with weekly physical activity (r = − 0.40, p < 0.05) and the PCr/Pi ratio in the resting thigh muscle (r = − 0.41, p < 0.05). Conclusion: The present study implies a link between systemic inflammation, excessive MFI and a loss of bioenergetics in subjects with stable COPD.

Background: Elderly, multimorbid patients with advanced chronic obstructive pulmonary disease (COPD) and/or chronic heart failure (CHF) exhibit poor health-related quality of life (HRQoL). Telemonitoring, based on digital pen technology, supported by hospital-based home care (HBHC) significantly reduces the number of hospitalizations. We hypothesized that the same intervention would prevent the deterioration of HRQoL that follows upon disease progression. Methods: Elderly computer-illiterate subjects with ≥ 2 hospitalizations the previous year were included. HRQoL was assessed at inclusion (baseline) and at 1, 6 and 12 months employing EuroQol-5 Dimensions (EQ-5D) and RAND-36 for general HRQoL, and Minnesota Living with Heart Failure Questionnaire (MLHFQ) and St. Georges Respiratory Questionnaire (SGRQ) for disease-specific HRQoL. Healthcare contacts, hospitalizations, as-needed medications, prescription changes and healthcare costs were registered. Results: Ninety-four patients were enrolled of which 53 subjects completed the 12-month study period. Compared to baseline, most domains of RAND-36 were improved significantly at 1 time-point or more. Only among COPD subjects, the disease-specific HRQoL was worsened at the 12 month evaluation. Measures of healthcare dependency were associated with poor HRQoL. Conclusion: The Health Diary system and HBHC together improve general HRQoL, and measures of healthcare dependency are associated with HRQoL variables.

The Global Lung Function Initiative (GLI) has recently published international reference values for diffusing capacity of the lung for carbon monoxide (D_LCO). Lower limit of normal (LLN),i.e.the 5th percentile, usually defines impairedD_LCO. We examined if the GLI LLN forD_LCOdiffers from the LLN in a Swedish population of healthy, never-smoking individuals and how any such differences affect identification of subjects with respiratory burden.Spirometry,D_LCO, chest high-resolution computed tomography (HRCT) and questionnaires were obtained from the first 15 040 participants, aged 50–64 years, of the Swedish CArdioPulmonary bioImage Study (SCAPIS). Both GLI reference values and the lambda-mu-sigma (LMS) method were used to define the LLN in asymptomatic never-smokers without respiratory disease (n=4903, of which 2329 were women).Both the median and LLN forD_LCOfrom SCAPIS were above the median and LLN from the GLI (p<0.05). The prevalence ofD_LCO<GLI LLN (and also GLI LLN but GLI LLN but <SCAPIS LLN (n=860) had more emphysema (14.3%versus4.5%, p<0.001), chronic airflow limitation (8.5%versus3.9%, p<0.001) and chronic bronchitis (8.3%versus4.4%, pGLI LLN and >SCAPIS LLN). No differences were found with regard to physician-diagnosed asthma.The GLI LLN forD_LCOis lower than the estimated LLN in healthy, never-smoking, middle-aged Swedish adults. Individuals withD_LCOabove the GLI LLN but below the SCAPIS LLN had, to a larger extent, an increased respiratory burden. This suggests clinical implications for choosing an adequate LLN for studied populations.

Background: Elderly patients with advanced stages of COPD or chronic heart failure (CHF) often require hospitalization due to exacerbations. We hypothesized that telemonitoring supported by hospital-based home care (HBHC) would detect exacerbations early, thus, reducing the number of hospitalization. We also speculated that patients with advanced COPD or CHF would present differences regarding exacerbation frequency and the need of HBHC. Methods: The Health Diary system, based on digital pen technology, was employed. Patients aged ≥65 years with ≥2 hospitalizations the previous year were included. Exacerbations were categorized and treated as either COPD or CHF exacerbation by an experienced physician. All HBHC contacts (home visits or telephone consultations) were registered. Results: Ninety-four patients with advanced diseases were enrolled (36 COPD and 58 CHF subjects) of which 53 subjects (19 COPD and 34 CHF subjects) completed the 1-year study period. Death was the major reason for not finalizing the study. Compared to the 1-year prior inclusion, the intervention significantly reduced hospitalization. Although COPD subjects were younger with less comorbidity, exacerbations and HBHC contacts were significantly greater in this group. Conclusions: COPD subjects exhibit exacerbations more frequently, mainly due to disease characteristics, thus, demanding much more HBHC.