Cluster analysis identifies a pathophysiologically distinct subpopulation with increased serum leptin levels and severe obstructive sleep apnea.

PURPOSE: To investigate the different pathophysiologies of obstructive sleep apnea (OSA) phenotypes using cluster analysis. Differences between leptin/adiponectin levels in the resulting OSA phenotypes were also examined. METHODS: In total, 1057 OSA patients were selected, and a retrospective survey of clinical records, polysomnography results, and blood gas data was conducted. Patients were grouped into four clusters by their OSA severity, PaCO2, body mass index (BMI), and sleepiness. A k-means cluster analysis was performed, resulting in a division into four subpopulations. The Tukey or Games-Howell tests were used for intergroup comparisons. RESULTS: Among the 20 clinical OSA items, four common factors (Epworth Sleepiness Scale [ESS], BMI, Apnea-Hypopnea Index [AHI], and PaCO2) were extracted by principal component analysis, and a cluster analysis was performed using the k-means method, resulting in four distinct phenotypes. The Clusters 1 (middle age, symptomatic severe OSA) and 4 (young, obese, symptomatic very severe OSA) exhibited high leptin levels. C-reactive protein levels were also elevated in Cluster 4, indicating a different pathophysiological background. No apparent differences between clusters were observed regarding adiponectin/leptin ratios and adiponectin levels. Classification into groups based on phenotype showed that Epworth Sleepiness Scale [ESS] score and disease severity were not correlated, suggesting that sleepiness is affected by multiple elements. CONCLUSIONS: The existence of multiple clinical phenotypes suggests that different pathophysiological backgrounds exist such as systemic inflammation and metabolic disorder. This classification may be used to determine the efficacy of continuous positive airway pressure treatment that cannot be determined by the AHI.

Validity study of the Japanese version of the Nijmegen Questionnaire for verifying dysfunctional breathing in Japanese asthma patients.

Background: Dysfunctional breathing (DB) is a clinical condition characterized by irregular breathing patterns presenting a sensation of dyspnea and a feeling of chest tightness. DB is a known comorbidity of asthma that is difficult to control, leading to poor quality of life, so early diagnosis and therapeutic intervention are essential to improve the clinical condition of asthma. The Nijmegen Questionnaire (NQ), developed to screen for DB and translated into various languages, is used worldwide. However, a Japanese NQ (JNQ) is unavailable, so DB has not been clinically verified in people with asthma in Japan. Objective: This study aimed to prepare a JNQ, verify its reliability and validity, and demonstrate its clinical benefits in asthma treatment. Methods: The JNQ was prepared by back-translating the NQ with the author's consent. The answers to self-administered questionnaires, including the JNQ, Asthma Control Test (ACT), Asthma Control Questionnaire (ACQ), Mini Asthma Quality of Life Questionnaire (Mini-AQLQ), and Patient Health Questionnaire 9 (PHQ-9), were obtained with the consent of 68 people with asthma (average age ± SD, 52.04 ± 12.43 years) who visited Nihon University Itabashi Hospital. The reliability of the JNQ was analyzed by the Cronbach alpha coefficient. A comparative test was conducted for each questionnaire (ACT, ACQ, Mini-AQLQ, PHQ-9), considering a JNQ score of 23 as the cutoff value. Patients with a score of 23 or more were assigned to the DB group, whereas patients with a score of less than 23 were assigned to the non-DB group. We analyzed the correlation between the JNQ and each questionnaire. Results: The JNQ showed sufficient reliability (Cronbach alpha = 0.875). Correlation analysis between the JNQ score and each questionnaire revealed negative correlations with the ACT score (r = 0.262) and Mini-AQLQ score (r = -0.453) and positive correlations with the ACQ score (r = 0.337) and PHQ-9 score (r = 0.539). All of these correlations were statistically significant. As a result of the comparative test, the DB and non-DB groups showed a significant difference in Mini-AQLQ (P = .023) and PHQ-9 (P = .003) scores. No significant difference was observed between ACT (P = .294) and ACQ (P = .177) scores. Conclusions: The JNQ validates DB in Japanese people with asthma and reflects the deterioration of asthma control, decreased quality of life, and depression. Using the JNQ, early diagnosis and therapeutic intervention (eg, breathing exercises and a psychosomatic approach) for DB in people with asthma may help suppress the severity of asthma in Japan.

The Relationship between Leptin Levels and Continuous Positive Airway Pressure Treatment: A Cluster Analysis.

Objective Leptin is an appetite-suppressing hormone released by adipose tissue that plays an important role in severe obstructive sleep apnea syndrome (OSAS). However, it is unclear whether leptin levels are a useful biomarker for this syndrome. The present study aimed to assess the effect of continuous positive airway pressure (CPAP) treatment on the syndrome according to leptin levels, using a cluster classification based on clinical features of the syndrome. Materials and Methods We performed a hierarchical cluster analysis of data from 97 OSAS patients diagnosed via polysomnography. We also evaluated the effect after 6 months of CPAP administration. Results Clusters 1 (49 patients; 50.5%) and 2 (6 patients; 6.2%) presented normal leptin levels, and clusters 3 (11 patients; 11.3%) and 4 (31 patients; 32%) presented high leptin levels. Clusters 3 and 4 presented different leptin levels, but the same degree of obesity. After treatment, the levels of excessive daytime sleepiness improved in all clusters. In Cluster 3, leptin levels were significantly reduced after treatment. Conclusion Using the conventional diagnostic method of the apnea-hypopnea index, it was not clear whether leptin is a useful biomarker for the CPAP treatment. However, it may be helpful for particular clusters, including obese women, and where particular populations require CPAP treatment.

Relation between postpartum calf-licking behavior and agonistic behavior against handlers by primiparous beef cows.

Maternal protective behavior in cattle husbandry settings is typically manifested as agonistic behavior against farm staff handling the calves. Investigating factors related to agonistic behavior of cows is important. Agonistic behaviors of 30 primiparous cows against farm staff handling their calves during the immediate postpartum period were observed using continuous recording. Relations between this agonistic behavior and calf-licking behavior were also analyzed for 2 h postpartum. Agonistic behavior was exhibited by 11 cows: 10 first displayed it during the first hour postpartum, whereas one displayed it during the second hour postpartum. Cows showing agonistic behavior spent a significantly longer time engaged in licking behavior during the first 2 h postpartum than the cows not showing agonistic behavior (p < 0.05). Although cows exhibiting agonistic behavior were likely to exhibit more calf-licking behavior, particularly during the first hour postpartum, than those not exhibiting agonistic behavior (p = 0.08), no difference was found in the proportion of time used for calf-licking during the second hour postpartum (p = 0.61). Results suggest an association between agonistic behavior against humans and greater calf-licking behavior in primiparous cows immediately postpartum.

Analysis of Aß-induced neurotoxicity and microglial responses in simple two- and three-dimensional human iPSC-derived cortical culture systems.

The extracellular accumulation of amyloid-ß (Aß) in plaques and associated neurodegeneration are the pathological hallmarks of Alzheimer's disease (AD). These plaques are surrounded by microglia-the resident tissue macrophages of the brain parenchyma that originate from primitive macrophages from the embryonic yolk sac. Microglia, including a unique subpopulation called "disease-associated microglia" (DAM), are strongly implicated in AD pathology; however, their exact function and physiology remain largely unknown. Notably, simple cell and tissue culture systems that adequately recreate the brain microenvironment and can simulate critical aspects of AD pathology could fundamentally contribute to elucidating microglial function in disease development and progression. Thus, we added human-induced pluripotent stem cell (hiPSC)-induced primitive macrophages (hiMacs) to hiPSC-induced cortical neurons (cell model) and cortical organoids (tissue model). The treatment of these culture systems with the O-acyl isopeptide of Aß1-42, which reverts to natural extracellular Aß1-42 at neutral pH and starts self-aggregation, caused the degeneration of hiPSC-induced cortical neurons in 2D culture and within cortical organoid cultures. Notably, the hiMacs phagocytosed extracellular Aß and exhibited a DAM-like phenotype. In both cell and tissue organoid culture systems, neurodegeneration was attenuated by the addition of hiMacs. Moreover, in cortical organoids, Aß plaques formed more circular and fewer hotspot-like morphological structures in the vicinity of hiMacs. These findings demonstrate the utility of simple hiPSC-induced cortical cell and tissue culture systems supplemented with hiMacs for elucidating critical aspects of AD pathology, such as microglial function and physiology. Adopting such systems in routine research practice may lead to the development of novel therapeutic strategies for AD.

Iron-Dependent Mitochondrial Dysfunction Contributes to the Pathogenesis of Pulmonary Fibrosis.

Although the pathogenesis of pulmonary fibrosis remains unclear, it is known to involve epithelial injury and epithelial-mesenchymal transformation (EMT) as a consequence of cigarette smoke (CS) exposure. Moreover, smoking deposits iron in the mitochondria of alveolar epithelial cells. Iron overload in mitochondria causes the Fenton reaction, leading to reactive oxygen species (ROS) production, and ROS leakage from the mitochondria induces cell injury and inflammation in the lungs. Nevertheless, the mechanisms underlying iron metabolism and pulmonary fibrosis are yet to be elucidated. In this study, we aimed to determine whether iron metabolism and mitochondrial dysfunction are involved in the pathogenesis of pulmonary fibrosis. We demonstrated that administration of the iron chelator deferoxamine (DFO) reduced CS-induced pulmonary epithelial cell death, mitochondrial ROS production, and mitochondrial DNA release. Notably, CS-induced cell death was reduced by the administration of an inhibitor targeting ferroptosis, a unique iron-dependent form of non-apoptotic cell death. Transforming growth factor-ß-induced EMT of pulmonary epithelial cells was also reduced by DFO. The preservation of mitochondrial function reduced Transforming growth factor-ß-induced EMT. Furthermore, transbronchial iron chelation ameliorated bleomycin-induced pulmonary fibrosis and leukocyte migration in a murine model. Our findings indicate that iron metabolism and mitochondrial dysfunction are involved in the pathogenesis of pulmonary fibrosis. Thus, they may be leveraged as new therapeutic targets for pulmonary fibrosis.

DsRNA induction of microRNA-155 disrupt tight junction barrier by modulating claudins.

BACKGROUND: The impaired barrier function of the airway epithelium due to RNA virus infection is closely related to the development and exacerbation of allergic airway inflammation. OBJECTIVE: In this study, we investigated the roles of microRNAs on the mechanisms of double-stranded RNA (dsRNA)-induced epithelial barrier dysfunction. METHODS: 16HBE14o- human bronchial epithelial cells were grown to confluence on Transwell inserts and exposed to poly-I:C. We studied epithelial barrier function by measuring transepithelial electrical resistance and paracellular flux of fluorescent markers and structure of tight junctions by immunofluorescence microscopy. RESULTS: Poly-I:C treated 16HBE14o- cells increased paracellular permeability. Knockdown of Toll-like receptor 3 and TRIF abrogated these effects. The expression of microRNA-155 (miR-155) was increased by poly-I:C in dose-dependent manner. Transfection of mir155 mimics into 16HBE14o- cells increased permeability and inhibited tight junction formation. Transfection of miR-155 inhibitor suppressed poly-I:C-induced barrier disruption. Poly-I:C treatment significantly decreased the expression of claudin members-claudin-1, -3, -4, -5, -9, -11, -16, -18 and -19. Transfection of miR-155 mimics showed similar changing expression pattern of claudin members with those of poly-I:C treatment. CONCLUSION: These results suggest that RNA virus infection can impair the epithelial barrier disruption mechanism by down-regulation of claudin members through the induction of miR-155.

Hijacking the Heme Acquisition System of Pseudomonas aeruginosa for the Delivery of Phthalocyanine as an Antimicrobial.

To survive in the iron-devoid environment of their host, pathogenic bacteria have devised multifarious cunning tactics such as evolving intricate heme transport systems to pirate extracellular heme. Yet, the potential of heme transport systems as antimicrobial targets has not been explored. Herein we developed a strategy to deliver antimicrobials by exploiting the extracellular heme acquisition system protein A (HasA) of Pseudomonas aeruginosa. We demonstrated that, analogous to heme uptake, HasA can specifically traffic an antimicrobial, gallium phthalocyanine (GaPc), into the intracellular space of P. aeruginosa via the interaction of HasA with its outer membrane receptor HasR. HasA enables water-insoluble GaPc to be mistakenly acquired by P. aeruginosa, permitting its sterilization (>99.99%) by irradiation with near-infrared (NIR) light, irrespective of antibiotic resistance. Our findings substantiate that bacterial heme uptake via protein-protein recognition is an attractive target for antimicrobials, enabling specific and effective sterilization.