Citations

Supplemental O 2 (hyperoxia) in premature infants detrimentally affects bronchial airways leading to increased senescence. Understanding the mechanisms by which hyperoxia initiates senescence in developing airways is critical for future therapeutic strategies. The current study showed that hyperoxia-induced senescence is mediated through increased mitochondrial reactive oxygen species and endoplasmic reticulum (ER) stress. ER stress inhibitors or mitochondria-targeted antioxidants may represent future therapies to blunt detrimental effects of supplemental oxygen in developing lungs.

Abstract The lung is an inherently mechanosensitive organ, where cells of the airway and parenchyma experience a range of mechanical forces throughout life including shear, stretch, and compression, in both health and disease. In this regard, pediatric and adult lung diseases such as wheezing and asthma, bronchopulmonary dysplasia (BPD), chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF) all involve macroscopic and cellular changes to the mechanical properties of the bronchial airways and/or parenchyma to varying extents. Accordingly, understanding how mechanical forces are sensed in the lung, and the responses of cells and tissues in the context of normal development and health versus disease conditions becomes highly relevant. There is increasing recognition that transduction of mechanical forces into cellular responses involves a number of channels, some of which are inherently mechanosensitive. Such channels trigger mechanotransduction pathways that may further mediate cellular remodeling, inflammation, and other pathophysiologic mechanisms in response to stretch, stiffness, and inflammatory cascades. Two particularly important channel families have emerged in pulmonary pathophysiology: the transient receptor potential vanilloid family with focus on member TRPV4 and the recently identified Piezo (PZ) channels. Here, we explore current understanding of the contributions of TRPV4 and PZ channels in lung health and disease states, focusing on the interactions between these mechanosensitive channels and their local environment including immune cells, the extracellular matrix, and cellular cytoskeletal elements. We further discuss potential areas for future research to better understand the impact of mechanical channels on pulmonary health and disease. © 2023 American Physiological Society. Compr Physiol 13:5157‐5178, 2023.

ABSTRACTBackgroundInsomnia and substance use disorders (SUD) are common comorbidities of bipolar disorder (BD). Genome‐wide association studies (GWAS) have uncovered shared genetic contributions to insomnia and BD as well as SUDs and BD. Electronic health record (EHR) derived phenotypes (phecodes) and questionnaire data were used to examine the relationship between insomnia genetic liability and SUDs in BD.Methods40,839 participants from the Mayo Clinic Bipolar Disorder Biobank (BD Biobank; n = 774) and Mayo Clinic Biobank (n = 485 BD cases, n = 39,580 controls) were included in the analyses of diagnosis (phecode) outcomes (insomnia, SUD, alcohol use disorder [AUD] and tobacco use disorder [TUD]). Analyses of specific SUD outcomes obtained through the BD Biobank questionnaire included 1789 cases and considered BD subtype. Logistic regression was used to test for associations between insomnia polygenic risk scores (PRS) and insomnia and SUD outcomes in BD cases and controls.ResultsInsomnia PRS was associated with having an insomnia diagnosis (phecode) in the EHR in controls (OR = 1.19, p = 9.64e‐33) but not in BD cases (OR = 1, p = 0.95). Associations between insomnia PRS and SUD diagnoses were significant in BD cases and controls, with the association being stronger in BD cases (interaction p = 0.024). In the BD Biobank data, the insomnia PRS was associated with increased odds of AUD (OR = 1.19, p = 4.26e‐04), TUD (OR = 1.21, p = 1.25e‐05) and cannabis use disorder (OR = 1.16, p = 4.19e‐03).ConclusionThe effect of genetic predisposition to insomnia on SUD risk may be stronger in BD cases than in controls, which could have clinical care implications for individuals with BD and comorbid SUD.

Abstract Human chromosomal anomalies, notably trisomies, disrupt gene expression, leading to diverse cellular and organ phenotypes. Increased cellular senescence (SEN) and oxidative stress in trisomies have gained recent attention. We assessed SEN, SEN-associated secretory phenotype (SASP), and oxidative stress on trisomy 13 (T13), T18, and T21 human fetal lung tissues and isolated primary human fetal lung fibroblasts. Telomerase-associated foci staining showed DNA damage primarily within T21 and T18 lungs. These results were confirmed by real-time quantitative PCR showing an increase of the SEN marker CDKN2B and SASP markers IL-6 and CXCL8. In contrast, lung tissues from T13 showed an upregulation of CDKN2A, whereas no significant changes in SASP marker genes were observed. γ-H2AX (H2A histone family member X) was upregulated in each genotype, particularly in T21. Isolated fibroblasts demonstrated a strong association between T21 and several SEN markers. An increase of γ-H2AX–positive cells were observed in fibroblasts from T21, T18, and T13, but only T21 exhibited an increase in P21 expression. Only T21 fibroblasts displayed a significant increase in reactive oxygen species levels, as indicated by MitoSOX and CellROX. This study provides the first evidence of a link between SEN and trisomy anomalies during prenatal human lung development, particularly in T21.

Background Bicuspid aortic valve (BAV) is the most common congenital heart defect in adults, often leading to complications such as thoracic aortic aneurysms and aortic stenosis. While BAV is frequently associated with 22q11.2 deletion syndrome (22q11.2DS), the contribution of rare copy number variants (CNVs) in this region to non-syndromic BAV is less clear. This study is aimed to assess the role of rare 22q11.2 CNVs in patients with early-onset BAV (EBAV) and to determine whether these variants are linked to an increased risk of complications. Methods Whole genome microarray genotyping was conducted on 272 patients with BAV with early onset valve or aortic disease (EBAV) and 272 biological relatives. CNVs were detected using three independent algorithms, focusing on the 22q11.2 region (18–24 Mb). CNV burden in the EBAV cohort was compared with unselected European ancestry controls. Results Rare duplications and deletions within the 22q11.2 region, particularly involving genes associated with cardiac development, were identified in 7.4% of EBAV probands. These CNVs were significantly enriched compared with the general population and segregated with BAV in families. Individuals carrying rare 22q11.2 CNVs had a higher prevalence of psychiatric diagnoses and learning difficulties, although they did not exhibit the typical features of 22q11.2DS. Importantly, these CNVs were associated with early onset or complex BAV cases, underscoring their potential clinical relevance. Conclusions Rare 22q11.2 CNVs play a role in non-syndromic BAV, particularly in cases with early onset or complex presentations. CNV screening could be considered as part of risk stratification for patients with BAV, helping to predict complications and guide management. Trial registration number NCT01823432 .

AbstractA 57-year-old male patient who underwent an open hemiarch repair with a femoral–femoral crossover bypass and right lower extremity fasciotomies for an acute Type A aortic dissection with limb ischemia presented 5 weeks' postrepair with a 20-pound weight loss due to intermittent hemodynamic collapse of the dissection flap over the origin of the superior mesenteric artery. This case highlights the challenges a dissection flap can cause after an urgent Type A aortic dissection repair.