Project description:Akap1 KO and Wt mice were exposed to normoxia or hyperoxia for 48h. Total RNA was extracted from lungs of Wt Normoxia (n=3), Wt hyperoxia (n=3), Akap1 KO (n=3) and Akap1 hyperoxia (n=3) mice. RNA-sequencing was carried out followed by differential expression of genes in the following groups. Wt Normoxia vs Wt Hyperoxia, Akap1 KO Normoxia versus Akap1 KO Hyperoxia, Wt Normoxia versus Akap1 KO Normoxia and Wt Hperoxia versus Akap1 Hyperoxia.
Project description:Background: Bronchopulmonary dysplasia (BPD), the most common complication of extreme preterm birth, can be caused by oxygen-related lung injury and is characterized by impaired alveolar and vascular development. Mesenchymal stromal cells (MSCs) have lung protective effects. Conversely, BPD is associated with increased MSCs in tracheal aspirates. Objective: To determine whether endogenous lung (L-)MSCs are perturbed in a well-established oxygen-induced rat model mimicking BPD features. Methods: Rat pups were exposed to room air or 95% oxygen from birth to postnatal day 10. On day 12, CD146+ L-MSCs were isolated and characterized according to the International Society for Cellular Therapy criteria. Epithelial and vascular repair potential were tested by scratch assay and endothelial network formation respectively, immune function by mixed lymphocyte reaction assay. Microarray analysis was performed using the Affymetrix GeneChip and gene set enrichment analysis (GSEA) software. Results: CD146+ L-MSCs isolated from rat pups exposed to hyperoxia had decreased CD73 expression and inhibited lung endothelial network formation. CD146+ L-MSCs indiscriminately promoted epithelial wound healing and limited T-cell proliferation. Expression of potent anti-angiogenic genes of the axonal guidance cue and CDC42 pathways was increased after in vivo hyperoxia, whereas genes of the anti-inflammatory JAK/STAT and lung/vascular growth promoting Fibroblast Growth Factor (FGF) pathways were decreased. Conclusions: In vivo hyperoxia exposure alters the pro-angiogenic effects and FGF expression of L-MSCs. Additionally, decreased CD73 and JAK/STAT expression suggest decreased immune function. L-MSC function may be perturbed and contribute to BPD pathogenesis. These findings may lead to improvements in manufacturing exogenous MSCs with superior repair capabilities.
Project description:We performed miRNA array analysis from 4 groups (neonatal lung control, neonatal lung after hyperoxia, adult lung control, adult lung after hyperoxia). We used pools of every 100ng of total RNA of three samples for each groups.
Project description:We evaluated the transcriptional changes in the aorta and kidney of 1 year old rats that were exposed to hyperoxia or normoxia in the neonatal period.
Project description:Background: Metabolic dysregulation has been implicated in bronchopulmonary dysplasia development. Taurine is an essential amino acid for neonates and is critically involved in glucose and fatty acid metabolism. Neonatal tissue obtains taurine mainly through the taurine transporter. The biological role of taurine in neonatal lung development has never been explored. As glucose metabolism mechanistically modulates angiogenesis and angiogenesis is the central player for neonatal lung development, we hypothesize that taurine depletion contributes to bronchopulmonary dysplasia development. Results: Although most genes and proteins for oxidative phosphorylation were enriched in hyperoxia pup lungs, the complex-1 activity decreased. The decrease in taurine-dependent complex-1 core subunits, ND5 and ND6, in hyperoxia lungs reasonably explained the discrepancy. Metabolomics analysis demonstrated decreased lung taurine with increased blood taurine of hyperoxia pups, compatible with the decreased taurine transporter expression. Decreased glycosylation and increased degradation explained the decreased taurine transporter expression. The results of the complementary study using tunicamycin and tauroursodeoxycholic acid studies supported that endoplasmic reticulum stress contributes to decreased taurine transporter expression in hyperoxia lungs. The effect of taurine treatment on reducing endoplasmic reticulum stress, increasing ND5 and ND6 expression, angiogenesis, and, most importantly, the alveolar formation is beneficial to hyperoxia rat pups. Conclusion: Hyperoxia exposure causes endoplasmic reticulum stress, increases taurine transporter degradation, and leads to taurine depletion in the neonatal lungs with subsequent metabolic dysregulation, resulting in poor alveolar formation of the neonatal lungs. We provide evidence of the never-being-reported protective role of taurine in neonatal lung development. The fact that taurine attenuates the severity of bronchopulmonary dysplasia by reducing hyperoxia-induced endoplasmic reticulum stress and mitochondrial dysfunction indicates its therapeutic potential for treating bronchopulmonary dysplasia.
Project description:In this study the microRNA expression of primary murine (C57BL/6) lung alveolar type II cells belonging to four different conditions was analyzed. Effects of hyperoxia 24 hours group were compared to the normoxia 24 hours and effects of the hyperoxia 6 hours group were compared to the normoxia 6 hours.