Assessment of Beta-2 Microglobulin Gene Edited Airway Epithelial Stem Cells as a treatment for Sulfur Mustard Inhalation.

Respiratory system damage is the primary cause of mortality in individuals who are exposed to vesicating agents including sulfur mustard (SM). Despite these devastating health complications, there are no fielded therapeutics that are specific for such injuries. Previous studies reported that SM inhalation depleted the tracheobronchial airway epithelial stem cell (TSC) pool and supported the hypothesis, TSC replacement will restore airway epithelial integrity and improve health outcomes for SM-exposed individuals. TSC express Major Histocompatibility Complex (MHC-I) transplantation antigens which increases the chance that allogeneic TSC will be rejected by the patient's immune system. However, previous studies reported that Beta-2 microglobulin (B2M) knockout cells lacked cell surface MHC-I and suggested that B2M knockout TSC would be tolerated as an allogeneic graft. This study used a Cas9 ribonucleoprotein (RNP) to generate B2M-knockout TSC, which are termed Universal Donor Stem Cells (UDSC). Whole genome sequencing identified few off-target modifications and demonstrated the specificity of the RNP approach. Functional assays demonstrated that UDSC retained their ability to self-renew and undergo multilineage differentiation. A preclinical model of SM inhalation was used to test UDSC efficacy and identify any treatment-associated adverse events. Adult male Sprague-Dawley rats were administered an inhaled dose of 0.8 mg/kg SM vapor which is the inhaled LD50 on day 28 post-challenge. On recovery day 2, vehicle or allogeneic Fisher rat UDSC were delivered intravenously (n = 30/group). Clinical parameters were recorded daily, and planned euthanasia occurred on post-challenge days 7, 14, and 28. The vehicle and UDSC treatment groups exhibited similar outcomes including survival and a lack of adverse events. These studies establish a baseline which can be used to further develop UDSC as a treatment for SM-induced airway disease.

Factors Associated with Neurodevelopmental Impairment in Bronchopulmonary Dysplasia.

OBJECTIVE: To identify factors associated with neurodevelopmental impairment (NDI) in patients with bronchopulmonary dysplasia (BPD). STUDY DESIGN: We identified 151 patients with moderate to severe BPD from 2010 to 2014 with complete Bayley Scales of Infant Development (BSID) scores at 24 months corrected age. We defined NDI as any diagnosis of cerebral palsy or ≥1 BSID composite scores of <80. RESULTS: The mean corrected age at BSID was 23 ± 1 months; 18% had a cognitive score of <80, 37% had a communication score of <80, and 26% had a motor score of <80. Cerebral palsy was diagnosed in 22 patients (15%); 84 (56%) patients did not have NDI. Patients with NDI had lower birth weight, but there was no difference in gestational age at birth, severe intraventricular hemorrhage (IVH), necrotizing enterocolitis, or patent ductus arteriosus ligation compared with patients with no NDI. Ventilator days were greater in patients with NDI than in patients without NDI. More patients with NDI received furosemide and systemic corticosteroids and the hospital length of stay was longer than in patients with no NDI. Logistic regression modeling demonstrated that for every additional 100 g of birth weight the odds of NDI decreased by 35% and for every additional hospital day the odds of NDI increased by 1.3%. CONCLUSIONS: In our cohort of patients with moderate to severe BPD, the majority had no NDI, and low birth weight and length of hospital stay were associated with increased risk of developing NDI. This finding suggests that there are potentially modifiable factors associated with better neurodevelopmental outcomes in patients with BPD that deserve further study.

Regulation of Human Airway Epithelial Tissue Stem Cell Differentiation by ß-Catenin, P300, and CBP.

The wingless/integrase-1 (WNT)/ß-catenin signaling pathway is active in several chronic lung diseases including idiopathic pulmonary fibrosis, asthma, and chronic obstructive pulmonary disease. Although this WNT/ß-catenin pathway activity is associated with an increase in mucus cell frequency and a decrease in ciliated cell frequency, a cause and consequence relationship between signaling and cell frequency has not been established. We previously demonstrated that genetic stabilization of ß-catenin inhibited differentiation of mouse bronchiolar tissue stem cells (TSC). This study determined the effect of ß-catenin and its co-factors P300 (E1A-binding protein, 300 kDa) and cAMP response element binding (CREB)-binding protein (CBP) on human bronchial epithelial TSC differentiation to mucus and ciliated cells. We developed a modified air-liquid interface (ALI) culture system in which mucus and ciliated cell frequency is similar. These cultures were treated with the ß-catenin agonist CHIR99021 (CHIR) and antagonists to ß-catenin (XAV939), P300 (IQ1), and CBP (ICG001). We report that human TSC differentiation to mucus and ciliated cells can be divided into two stages, specification and commitment. CHIR treatment inhibited mucus and ciliated cell commitment while XAV939 treatment demonstrated that ß-catenin was necessary for mucus and ciliated cell specification. Additional studies demonstrate that a ß-catenin/P300 complex promotes mucus cell specification and that ß-catenin interacts with either P300 or CBP to inhibit ciliated cell commitment. These data indicate that activation of ß-catenin-dependent signaling in chronic lung disease leads to changes in mucus and ciliated cell frequency and that P300 and CBP tune the ß-catenin signal to favor mucus cell differentiation. Stem Cells 2018;36:1905-12.

Infant Pulmonary Function Testing and Phenotypes in Severe Bronchopulmonary Dysplasia.

BACKGROUND: The definition of severe bronchopulmonary dysplasia (sBPD) is based on respiratory support needs. The management of a patient with sBPD remains empirical and is highly variable among providers. Our objective in this study was to test the hypothesis that infant pulmonary function testing (iPFT) would reveal distinct phenotypes in patients with established sBPD during the initial NICU stay. METHODS: A prospective cohort study with data prospectively collected on infants with sBPD from May 1, 2003, to June 30, 2016. iPFT data were used to classify the patients as obstructive, restrictive, or mixed. RESULTS: The median gestational age at birth was 25 weeks (interquartile range [IQR], 24-27 weeks) and the median birth weight was 707 g (IQR, 581-925 g). At the time of iPFT, the median postmenstrual age was 52 weeks (IQR, 45-63 weeks), and the median weight was 4.4 kg (IQR, 3.7-6.0 kg). There were 56 (51%) patients with obstructive, 44 (40%) with mixed, and 10 (9%) with restrictive phenotypes. Moderate or severe obstruction was seen in 86% of the obstructive group and 78% of the mixed group. Of the restrictive patients, 70% had moderate and 30% had mild restriction. Bronchodilator response was seen in 74% of obstructive, 63% of mixed, and 25% of restrictive patients. CONCLUSIONS: Our findings reveal that sBPD as it is currently defined includes distinct phenotypes. Future researchers of diagnostic approaches to this population should consider the development of bedside tests to define phenotypes, and researchers in future therapeutic trials should consider the use of pulmonary function phenotyping in patient recruitment.

Pulmonary sequelae and functional limitations in children and adults with bronchopulmonary dysplasia.

Preterm infants with bronchopulmonary dysplasia (BPD) often suffer from life-long pulmonary impairments in pulmonary physical function. This review summarizes our current understanding of the chronic pulmonary impairments and physical functional limitations associated with BPD from preterm birth to adulthood. It also identifies opportunities for intervention in children and adults living with chronic lung disease (CLD) after preterm birth.

Hyperoxia increases hepatic arginase expression and ornithine production in mice.

Hyperoxic exposure affects the levels and activities of some hepatic proteins. We tested the hypothesis that hyperoxic exposure would result in greater hepatic .NO concentrations. C3H/HeN mice were exposed to >95% O(2) for 72 or 96 h and compared to room air-breathing controls. In contrast to our working hypothesis, exposure to >95% O(2) for 96 h decreased hepatic nitrite/nitrate NO(X) concentrations (10.9 +/- 2.2 nmol/g liver versus 19.3 +/- 2.4 nmol/g liver in room air, P < 0.05). The hepatic levels of endothelial NO synthase (eNOS) and inducible NOS (iNOS) proteins were not different among the groups. The arginases, which convert L-arginine to urea and L-ornithine, may affect hepatic NOS activities by decreasing L-arginine bioavailability. Hepatic ornithine concentrations were greater in hyperoxic animals than in controls (318 +/- 18 nmol/g liver in room air, and 539 +/- 64, and 475 +/- 40 at 72 and 96 h of hyperoxia, respectively, P < 0.01). Hepatic arginase I protein levels were greater in hyperoxic animals than in controls. Hepatic carbamoyl phosphate synthetase (CPS) protein levels and activities were not different among groups. These results indicate that increases in hepatic levels of arginase I in mice exposed to hyperoxia may diminish .NO production, as reflected by lower liver levels of NO(X). The resultant greater hepatic ornithine concentrations may represent a mechanism to facilitate tissue repair, by favoring the production of polyamines and/or proline.