SEAM is a spatial single nuclear metabolomics method for dissecting tissue microenvironment.

Spatial metabolomics can reveal intercellular heterogeneity and tissue organization. Here we report on the spatial single nuclear metabolomics (SEAM) method, a flexible platform combining high-spatial-resolution imaging mass spectrometry and a set of computational algorithms that can display multiscale and multicolor tissue tomography together with identification and clustering of single nuclei by their in situ metabolic fingerprints. We first applied SEAM to a range of wild-type mouse tissues, then delineated a consistent pattern of metabolic zonation in mouse liver. We further studied the spatial metabolic profile in the human fibrotic liver. We discovered subpopulations of hepatocytes with special metabolic features associated with their proximity to the fibrotic niche, and validated this finding by spatial transcriptomics with Geo-seq. These demonstrations highlighted SEAM's ability to explore the spatial metabolic profile and tissue histology at the single-cell level, leading to a deeper understanding of tissue metabolic organization.

Abnormal heart rate responses to exercise in non-severe COPD: relationship with pulmonary vascular volume and ventilatory efficiency.

BACKGROUND: Despite being a prognostic predictor, cardiac autonomic dysfunction (AD) has not been well investigated in chronic obstructive pulmonary disease (COPD). We aimed to characterise computed tomography (CT), spirometry, and cardiopulmonary exercise test (CPET) features of COPD patients with cardiac AD and the association of AD with CT-derived vascular and CPET-derived ventilatory efficiency metrics. METHODS: This observational cohort study included stable, non-severe COPD patients. They underwent clinical evaluation, spirometry, CPET, and CT. Cardiac AD was determined based on abnormal heart rate responses to exercise, including chronotropic incompetence (CI) or delayed heart rate recovery (HRR) during CPET. RESULTS: We included 49 patients with FEV1 of 1.2-5.0 L (51.1-129.7%), 24 (49%) had CI, and 15 (31%) had delayed HRR. According to multivariate analyses, CI was independently related to reduced vascular volume (VV; VV ≤ median; OR [95% CI], 7.26 [1.56-33.91]) and low ventilatory efficiency (nadir VE/VCO2 ≥ median; OR [95% CI], 10.67 [2.23-51.05]). Similar results were observed for delayed HRR (VV ≤ median; OR [95% CI], 11.46 [2.03-64.89], nadir VE/VCO2 ≥ median; OR [95% CI], 6.36 [1.18-34.42]). CONCLUSIONS: Cardiac AD is associated with impaired pulmonary vascular volume and ventilatory efficiency. This suggests that lung blood perfusion abnormalities may occur in these patients. Further confirmation is required in a large population-based cohort.

Prediction of exercise-induced desaturation in COPD patients without resting hypoxemia: a retrospective study.

BACKGROUND: There is no universally accepted criterion for assessing exercise-induced desaturation (EID). The purpose of this study is to compare the two methods regularly used for determining EID in COPD patients, as well as to explore the risk factors and predictors related to EID. METHODS: The 6MWT was performed with continuous SpO2 monitoring on patients with stable COPD. Using two methods (method A: "SpO2rest-SpO2min ≥ 4% and/or SpO2min < 90%", method B: "SpO2rest-SpO2end ≥ 4% and/or SpO2end < 90%") as EID determination criteria to assess the incidence of EID. The differences and consistency of the two methods are compared. Moreover, we collected data through the pulmonary function test, mMRC dyspnea score, COPD assessment test, BODE index and CT-defined emphysema. Univariate and multivariate logistic regression analyses were used to identify factors affecting the EID. For the parameters that predict EID in 6MWT, a receiver operating characteristic (ROC) curve analysis was employed. RESULTS: The analysis included 124 patients. The overall incidence of EID was 62.1% by using method A as the criterion and 51.6% by method B. All of the EID patients found by method B were included in the EID patients identified by method A, as well as 13 new-EID patients. The difference in diagnostic outcomes between the two approaches was not statistically significant (P > 0.05), but they were in excellent agreement (Kappa = 0.807, P = 0.001). Logistic regression analyses found that DLCO SB% pred, DLCO/VA% pred, CAT score, mean density, PD15, emphysema volume and %LAA were significant determinants of the EID. For predicting EID, the ROC analysis produced AUC and cutoffs of 0.689 and 50.45% (DLCO SB% pred), 0.707 and 75.0% (DLCO/VA% pred), 0.727 and 15 points (CAT score), 0.691 and - 955.00HU (PD15), 0.671 and - 856.46HU (mean density), 0.668 and 338.14 ml (emphysema volume) and 0.656 and 7.63% (%LAA), respectively. CONCLUSIONS: Two methods evaluating EID in this research are in a good agreement, method A can find more EID patients by focusing on SpO2min. When conditions are constrained, it is also sufficient to assess EID in COPD patients by method B. In terms of the predictors of EID, DLCO SB% pred, DLCO/VA% pred, CAT score and CT-defined emphysema are all statistically significant test variables to determine EID.

Exercise-Induced Oxygen Desaturation Increases Arterial Stiffness in Patients with COPD During the 6WMT.

Objective: Given the established impact of exercise in reducing arterial stiffness and the potential for intermittent hypoxia to induce its elevation, this study aims to understand how oxygen desaturation during exercise affects arterial stiffness in individuals with COPD. Methods: We enrolled patients with stable COPD from China-Japan Friendship Hospital from November 2022 to June 2023. The 6-minute walk test (6-MWT) was performed with continuous blood oxygen saturation (SpO2) monitoring in these patients. The patients were classified into three groups: non-exercise induced desaturation (EID), mild-EID and severe-EID, according to the changes in SpO2 during the 6-MWT. The Cardio-Ankle Vascular Index (CAVI) and the change in CAVI (ΔCAVI, calculated as CAVI before 6MWT minus CAVI after the 6MWT) were measured before and immediately after the 6MWT to assess the acute effects of exercise on arterial stiffness. GOLD Stage, pulmonary function, and other functional outcomes were also measured in this study. Results: A total of 37 patients with stable COPD underwent evaluation for changes in CAVI (ΔCAVI) before and after the 6-MWT. Stratification based on revealed three subgroups: non-EID (n=12), mild-EID (n=15), and severe-EID (n=10). The ΔCAVI values was -0.53 (-0.95 to -0.31) in non-EID group, -0.20 (-1.45 to 0.50) in mild-EID group, 0.6 (0.08 to 0.73) in severe-EID group. Parametric tests indicated significant differences in ΔCAVI among EID groups (p = 0.005). Pairwise comparisons demonstrated significant distinctions between mild-EID and severe-EID groups, as well as between non-EID and severe-EID groups (p = 0.048 and p = 0.003, respectively). Multivariable analysis, adjusting for age, sex, GOLD stage, diffusion capacity, and blood pressure, identified severe-EID as an independent factor associated with ΔCAVI (B = 1.118, p = 0.038). Conclusion: Patients with COPD and severe-EID may experience worsening arterial stiffness even during short periods of exercise.

Efficacy and safety of a music-therapy facilitated pulmonary telerehabilitation program in COPD patients: the COPDMELODY study protocol.

Despite considerable evidence for the benefit in chronic obstructive pulmonary disease (COPD), the implementation of pulmonary rehabilitation (PR) is insufficient. However, music therapy may help address this gap due to its unique benefits. Therefore, we aimed to develop a music-therapy facilitated pulmonary telerehabilitation program based on rhythm-guided walking, singing, and objective telemonitoring. A supervised, parallel-group, single-blinded, randomized controlled clinical trial will be conducted, including 75 patients with COPD anticipated to be randomized in a 1:1:1 ratio into three groups. The intervention groups will receive a 12-week remotely monitored rehabilitation program, while the usual care group will not receive any rehabilitation interventions. Of the two intervention groups, the multi-module music therapy group will contain rhythm-guided walking and singing training, while the rhythm-guided walking group will only include music tempo-guided walking. The primary outcome is the distance of the incremental shuttle walking test. Secondary outcomes include respiratory muscle function, spirometry, lower extremity function, symptoms, quality of life, anxiety and depression levels, physical activity level, training adherence, and safety measurements. The results of this study can contribute to develop and evaluate a home-based music-facilitated rehabilitation program, which has the potential to act as a supplement and/or substitute (according to the needs) for traditional center-based PR in patients with stable COPD. Clinical trial registration: https://classic.clinicaltrials.gov/, NCT05832814.

Eosinophils promote pulmonary matrix destruction and emphysema via Cathepsin L.

Patients with chronic obstructive pulmonary disease (COPD) who exhibit elevated blood eosinophil levels often experience worsened lung function and more severe emphysema. This implies the potential involvement of eosinophils in the development of emphysema. However, the precise mechanisms underlying the development of eosinophil-mediated emphysema remain unclear. In this study, we employed single-cell RNA sequencing to identify eosinophil subgroups in mouse models of asthma and emphysema, followed by functional analyses of these subgroups. Assessment of accumulated eosinophils unveiled distinct transcriptomes in the lungs of mice with elastase-induced emphysema and ovalbumin-induced asthma. Depletion of eosinophils through the use of anti-interleukin-5 antibodies ameliorated elastase-induced emphysema. A particularly noteworthy discovery is that eosinophil-derived cathepsin L contributed to the degradation of the extracellular matrix, thereby leading to emphysema in pulmonary tissue. Inhibition of cathepsin L resulted in a reduction of elastase-induced emphysema in a mouse model. Importantly, eosinophil levels correlated positively with serum cathepsin L levels, which were higher in emphysema patients than those without emphysema. Expression of cathepsin L in eosinophils demonstrated a direct association with lung emphysema in COPD patients. Collectively, these findings underscore the significant role of eosinophil-derived cathepsin L in extracellular matrix degradation and remodeling, and its relevance to emphysema in COPD patients. Consequently, targeting eosinophil-derived cathepsin L could potentially offer a therapeutic avenue for emphysema patients. Further investigations are warranted to explore therapeutic strategies targeting cathepsin L in emphysema patients.

Pulmonary rehabilitation restores limb muscle mitochondria and improves the intramuscular metabolic profile.

BACKGROUND: Exercise, as the cornerstone of pulmonary rehabilitation, is recommended to chronic obstructive pulmonary disease (COPD) patients. The underlying molecular basis and metabolic process were not fully elucidated. METHODS: Sprague-Dawley rats were classified into five groups: non-COPD/rest ( n  = 8), non-COPD/exercise ( n  = 7), COPD/rest ( n  = 7), COPD/medium exercise ( n  = 10), and COPD/intensive exercise ( n  = 10). COPD animals were exposed to cigarette smoke and lipopolysaccharide instillation for 90 days, while the non-COPD control animals were exposed to room air. Non-COPD/exercise and COPD/medium exercise animals were trained on a treadmill at a decline of 5° and a speed of 15 m/min while animals in the COPD/intensive exercise group were trained at a decline of 5° and a speed of 18 m/min. After eight weeks of exercise/rest, we used ultrasonography, immunohistochemistry, transmission electron microscopy, oxidative capacity of mitochondria, airflow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI), and transcriptomics analyses to assess rectal femoris (RF). RESULTS: At the end of 90 days, COPD rats' weight gain was smaller than control by 59.48 ±â€Š15.33 g ( P  = 0.0005). The oxidative muscle fibers proportion was lower ( P  < 0.0001). At the end of additional eight weeks of exercise/rest, compared to COPD/rest, COPD/medium exercise group showed advantages in weight gain, femoral artery peak flow velocity (Δ58.22 mm/s, 95% CI: 13.85-102.60 mm/s, P  = 0.0104), RF diameters (Δ0.16 mm, 95% CI: 0.04-0.28 mm, P  = 0.0093), myofibrils diameter (Δ0.06 µm, 95% CI: 0.02-0.10 µm, P  = 0.006), oxidative muscle fiber percentage (Δ4.84%, 95% CI: 0.15-9.53%, P  = 0.0434), mitochondria oxidative phosphorylate capacity ( P  < 0.0001). Biomolecules spatial distribution in situ and bioinformatic analyses of transcriptomics suggested COPD-related alteration in metabolites and gene expression, which can be impacted by exercise. CONCLUSION: COPD rat model had multi-level structure and function impairment, which can be mitigated by exercise.

Pulmonary telerehabilitation and efficacy among discharged COVID-19 patients: Rational and design of a prospective real-world study.

INTRODUCTION: The novel coronavirus disease 2019 (COVID-19) could cause physical and psychological dysfunction in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. Pulmonary telerehabilitation is strongly recommended due to the contagious nature of the disease, but its efficacy and benefit need to be comprehensively evaluated. METHODS: An 8-week pulmonary telerehabilitation programme is designed in a real-world and prospective manner, aiming to assess the efficacy of remote rehabilitation among discharged patients with COVID-19 from three designated hospitals in the epicenter of China (Wuhan City). The telerehabilitation programme includes physicians and physiotherapists remotely guided training (online) for 2 weeks, and patient self-managed rehabilitation (offline) for 6 weeks with assistance of information technology and digital device. The main rehabilitation intervention includes breathing exercise, respiratory muscle training, aerobic exercise, and resistance training. The primary outcome is 6-min walk distance, and secondly pulmonary function, respiratory muscle strength, physical activity, symptom, psychological status and quality of life, etc. will also be assessed. Patients will be followed up periodically at week two, four, eight after enrolment and at month one, three, six and 12 after the rehabilitation accomplished, respectively. Current study has been approved by the ethics committee of China-Japan Friendship Hospital and three participating centers in Wuhan City. DISCUSSION: We anticipate that the health status of discharged patients with COVID-19 could be improved through this systemic pulmonary telerehabilitation programme. The interdisciplinary remote mode of rehabilitation could be an optimal way in management of emerging respiratory tract infectious disease. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04368793.

The Heterogeneity of Inflammatory Response and Emphysema in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by chronic inflammation, emphysema, airway remodeling, and altered lung function. Despite the canonical classification of COPD as a neutrophilic disease, blood and airway eosinophilia are found in COPD patients. Identifying the tools to assess eosinophilic airway inflammation in COPD models during stable disease and exacerbations will enable the development of novel anti-eosinophilic treatments. We developed different animal models to mimic the pathological features of COPD. Our results show that eosinophils accumulated in the lungs of pancreatic porcine elastase-treated mice, with emphysema arising from the alveolar septa. A lipopolysaccharide challenge significantly increased IL-17 levels and induced a swift change from a type-2 response to an IL-17-driven inflammatory response. However, lipopolysaccharides can exacerbate cigarette smoking-induced airway inflammation dominated by neutrophil infiltration and airway remodeling in COPD models. Our results suggest that eosinophils may be associated with emphysema arising from the alveolar septa, which may be different from the small airway disease-associated emphysema that is dominated by neutrophilic inflammation in cigarette smoke-induced models. The characterization of heterogeneity seen in the COPD-associated inflammatory signature could pave the way for personalized medicine to identify new and effective therapeutic approaches for COPD.

Factors associated with inpatient length of stay among hospitalised patients with chronic obstructive pulmonary disease, China, 2016-2017: a retrospective study.

OBJECTIVES: To identify factors associated with length of stay (LOS) in chronic obstructive pulmonary disease (COPD) hospitalised patients, which may help shorten LOS and reduce economic burden accrued over hospital stay. DESIGN: A retrospective cohort study. SETTING: This study was performed in a tertiary hospital in China. PARTICIPANTS: Patients with COPD who were aged ≥40 years and newly admitted between 2016 and 2017. PRIMARY AND SECONDARY OUTCOME MEASURES: LOS at initial admission was the primary outcome and health expenditures were the secondary outcome. To identify factors associated with LOS, we collected information at index hospitalisation and constructed a conceptual model using directed acyclic graph. Potential factors were classified into five groups: demographic information, disease severity, comorbidities, hospital admission and environmental factors. Negative binomial regression model was fitted for each block of factors and a parsimonious analysis was performed. RESULTS: In total, we analysed 565 patients with COPD. The mean age was 69±11 years old and 69.4% were men. The median LOS was 10 (interquartile range 8-14) days. LOS was significantly longer in patients with venous thromboembolism (VTE) (16 vs 10 days, p=0.0002) or with osteoporosis (15 vs 10 days, p=0.0228). VTE ((rate ratio) RR 1.38, 95% CI 1.07 to 1.76), hypoxic-hypercarbic encephalopathy (RR 1.53, 95% CI 1.06 to 2.20), respiratory infection (RR 1.12, 95% CI 1.01 to 1.24), osteoporosis (RR 1.45, 95% CI 1.07 to 1.96) and emergence admission (RR 1.08, 95% CI 1.01 to 1.16) were associated with longer LOS. In parsimonious analysis, all these factors remained significant except emergency admission, highlighting the important role of concomitant morbidities in patients' hospital stay. Total hospitalisation cost and patients' out-of-pocket cost increased monotonically with LOS (both ptrend <0.0001). CONCLUSION: Patients' concomitant morbidities predicted excessive LOS in patients with COPD. Healthcare cost increased over the LOS. Quality improvement initiatives may need to identify patients at high risk for lengthy stay and implement early interventions to reduce COPD economic burden.

Association of RAGE gene multiple variants with the risk for COPD and asthma in northern Han Chinese.

Clinical and experimental data have shown that the receptor for advanced glycation end products (RAGE) is implicated in the pathogenesis of respiratory disorders. In this study, we genotyped five widely-evaluated variants in RAGE gene, aiming to assess their association with the risk for chronic obstructive pulmonary disease (COPD) and asthma in northern Han Chinese. Genotypes were determined in 105 COPD patients, 242 asthma patients and 527 controls. In single-locus analysis, there was significant difference in the genotype distributions of rs1800624 between COPD patients and controls (p=0.022), and the genotype and allele distributions of rs1800625 differed significantly (p=0.040 and 0.016) between asthma patients and controls. Haplotype analysis revealed that haplotype T-A-G-T (allele order: rs1800625, rs1800624, rs2070600, rs184003) was significantly associated with a reduced COPD risk (OR=0.32, 95% CI: 0.06-0.60), and haplotype T-A-A-G was significantly associated with a reduced asthma risk (OR=0.19, 95% CI: 0.04-0.96). Further haplotype-phenotype analysis showed that high- and low-density lipoprotein cholesterol and blood urea nitrogen were significant mediators for COPD (psim=0.041, 0.043 and 0.030, respectively), and total cholesterol was a significant mediator for asthma (psim=0.009). Taken together, our findings indicate that RAGE gene is a promising candidate for COPD and asthma, and importantly both disorders are genetically heterogeneous.

Human brain arteriovenous malformations are associated with interruptions in elastic fibers and changes in collagen content.

AIM: We hypothesized that the loss of structural integrity in vessels of brain arteriovenous malformations (bAVM) is associated with abnormal expression of collagen subtypes. MATERIAL AND METHODS: We retrospectively obtained the nidus tissue specimens from 24 bAVM patients and structurally normal cerebral cortex from six surgical epilepsy patients. The samples were paraffin-embedded and stained with Victoria blue and picrosirius red and examined by light microscopy. RESULTS: Light microscopy showed that collagen fibers became disorganized, and the internal elastic lamina was duplicated or interrupted in the arteries from the nidus tissue of bAVM. In some vessels in the nidus, Col I was the only collagen component and the interstitial tissue was mainly comprised of Col I. bAVM patients showed significantly higher Col I levels (86.25% ±13.92) and lower Col III levels (13.75% ±13.92) in the vasculature in the nidus tissue than those of otherwise normal surgical epilepsy patients (Col I, 80.78% ±18.03; Col III, 19.22% ±18.03) (p < 0.001). Additionally, bAVM patients showed a higher Col I / Col III ratio (24.71±40.47) than that of normal controls (16.04 ±31.28) (p < 0.001). CONCLUSION: bAVM patients exhibit changes in the Col I/Col III ratio and elastic fibers in the vasculature, which may compromise the structural integrity of cerebral vessels.