Project description:Study objectives: Chronic obstructive pulmonary disease and obstructive sleep apnea overlap syndrome is associated with excess mortality, and outcomes are related to the degree of hypoxemia. People at high altitude are susceptible to periodic breathing, and hypoxia at altitude is associated with cardio-metabolic dysfunction. Hypoxemia in these scenarios may be described as superimposed sustained plus intermittent hypoxia, or overlap hypoxia (OH), the effects of which have not been investigated. We aimed to characterize the cardio-metabolic consequences of OH in mice. Methods: C57BL/6J mice were subjected to either sustained hypoxia (SH, FiO2=0.10), intermittent hypoxia (IH, FiO2=0.21 for 12 hours, and FiO2 oscillating between 0.21 and 0.06, 60 times/hour, for 12 hours), OH (FiO2=0.13 for 12 hours, and FiO2 oscillating between 0.13 and 0.06, 60 times/hour, for 12 hours), or room air (RA), n=8/group. Blood pressure and intraperitoneal glucose tolerance test were measured serially, and right ventricular systolic pressure (RVSP) was assessed. Results: Systolic blood pressure transiently increased in IH and OH relative to SH and RA. RVSP did not increase in IH, but increased in SH and OH by 52% (p<0.001) and 20% (p=0.001). Glucose disposal worsened in IH and improved in SH, with no change in OH. Serum LDL and VLDL increased in OH and SH, but not in IH. Hepatic oxidative stress increased in all hypoxic groups, with the highest increase in OH. Conclusions: Overlap hypoxia may represent a unique and deleterious cardio-metabolic stimulus, causing systemic and pulmonary hypertension, and without protective metabolic effects characteristic of sustained hypoxia.
Project description:Salivary proteins of mouth breathing children were compared with paired nose breathing children using label-free quantification (LFQ). The differentially expressed proteins were screened (fold-change 1.5, p value<0.05).
Project description:Expression data from mice exposed to intermittent hypoxia and mice reared for 12 months. We used microarrays to analyze the transcriptome of hippocampus from mice exposed to intermittent hypoxia or aged mice.
Project description:Obstructive sleep apnea (OSA) is a highly prevalent condition with major neurocognitive and cardiovascular health effects. Positive airway pressure (PAP) therapy prevents the collapse of the pharyngeal airway to improve hypoxemia, hypercapnia, and sleep fragmentation caused by OSA. While adherence to PAP therapy has been thought to be a barrier to use, consistent usage is likely much higher than commonly thought. In addition, many strategies have been developed to assist providers in improving their patients' PAP adherence.
Project description:Walking catfish (Clarias macrocephalus) and channel catfish (Ictalurus punctatus) are freshwater fish species of the Siluriformes order. C. macrocephalus has both gills and modified gill structures serving as an air breathing organ (ABO) which allows them aerial breathing (AB), while I. punctatus does not possess an air-breathing organ (ABO), and thus cannot breathe in air. These two species provide an excellent model for studying the molecular basis of accessory air-breathing organ development in teleost fish. In this study, seven development stages in C. macrocephalus were selected for RNA-seq analysis to compare with channel catfish as the time when air breathing organ developed and became functional. Through comparative genetic contents analysis, 1,458 genes were identified to be present in C. macrocephalus, but absent from I. punctatus. Gene expression analysis and protein-protein intersection (PPI) analysis were performed, 26 genes were selected in C. macrocephalus, including mb, ngb, hbae genes, which are mainly associated with oxygen carrier activity, oxygen binding and heme binding activities. Our work provides a large data resource for exploring the genomic basis of air breathing function in C. macrocephalus and offers an insight into the adaption of aquatic organisms to hypoxia and high ammonia environment.