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Author(s): Chung-Ming Chen [sup.1] [sup.2] , Yi-Chun Liu [sup.2] , Yue-Jun Chen [sup.2] , Hsiu-Chu Chou [sup.3] Author Affiliations: (1) Department of Pediatrics, Taipei Medical University Hospital, 0000 0004 0639 [...], Purpose Oxygen therapy is often required to treat newborn infants with respiratory disorders. Prolonged exposure of neonatal rats to hyperoxia reduced alveolar septation, increased terminal air space size, and increased lung fibrosis; these conditions are very similar to those of human bronchopulmonary dysplasia. Epigenetic regulation of gene expression plays a crucial role in bronchopulmonary dysplasia development. Method We reared Sprague-Dawley rat pups in either room air (RA, n = 24) or an atmosphere containing 85% O.sub.2 (n = 26) from Postnatal Days 1 to 14. Methylated DNA immunoprecipitation (MeDIP) was used to analyze genome-wide DNA methylation in lung tissues of neonatal rats. Hyperoxia-exposed rats exhibited larger air spaces and thinner septa than RA-exposed rats did on Postnatal Day 14. The rats exposed to hyperoxia exhibited significantly higher mean linear intercepts than did the rats exposed to RA. We applied MeDIP next-generation sequencing for profiling changes in DNA methylation in the rat lungs exposed to hyperoxia and RA. We performed bioinformatics and pathway analyses on the raw sequencing data to identify differentially methylated candidate genes. Results Our in vivo model revealed that neonatal hyperoxia exposure arrested alveolarization on Postnatal Day 14. We found that the ErbB, actin cytoskeleton, and focal adhesion signaling pathways are epigenetically modulated by exposure to hyperoxia. We demonstrated that hyperoxia exposure contribute in delaying lung development through an epigenetic mechanism by disrupting the expression of genes in lungs that might be involved in alveolarization. Conclusions These data indicate that aberrant DNA methylation and deregulation of the actin cytoskeleton and focal adhesion pathways of lung tissues may be involved in the pathophysiology of hyperoxia-induced arrested alveolarization.

Among kidney cancers, clear cell renal cell carcinoma (ccRCC) has the highest incidence rate in adults. The survival rate of patients diagnosed as having metastatic ccRCC drastically declines even with intensive treatment. We examined the efficacy of simvastatin, a lipid-lowering drug with reduced mevalonate synthesis, in ccRCC treatment. Simvastatin was found to reduce cell viability and increase autophagy induction and apoptosis. In addition, it reduced cell metastasis and lipid accumulation, the target proteins of which can be reversed through mevalonate supplementation. Moreover, simvastatin suppressed cholesterol synthesis and protein prenylation that is essential for RhoA activation. Simvastatin might also reduce cancer metastasis by suppressing the RhoA pathway. A gene set enrichment analysis (GSEA) of the human ccRCC GSE53757 data set revealed that the RhoA and lipogenesis pathways are activated. In simvastatin-treated ccRCC cells, although RhoA was upregulated, it was mainly restrained in the cytosolic fraction and concomitantly reduced Rho-associated protein kinase activity. RhoA upregulation might be a negative feedback effect owing to the loss of RhoA activity caused by simvastatin, which can be restored by mevalonate. RhoA inactivation by simvastatin was correlated with decreased cell metastasis in the transwell assay, which was mimicked in dominantly negative RhoA-overexpressing cells. Thus, owing to the increased RhoA activation and cell metastasis in the human ccRCC dataset analysis, simvastatin-mediated Rho inactivation might serve as a therapeutic target for ccRCC patients. Altogether, simvastatin suppressed the cell viability and metastasis of ccRCC cells; thus, it is a potentially effective ccRCC adjunct therapy after clinical validation for ccRCC treatment. [ABSTRACT FROM AUTHOR]

Fetal growth restriction (FGR) is associated with reduced cardiac function in neonates. Uteroplacental insufficiency (UPI) is the most common cause of FGR. The mechanisms underlying these alterations remain unknown. We hypothesized that UPI would influence cardiac development in offspring rats. Through this study, we evaluated the effects of UPI during pregnancy on heart histology and pulmonary hypertension in growth-restricted newborn rats. On gestation Day 18, either UPI was induced through bilateral uterine vessel ligation (FGR group) or sham surgery (control group) was performed. The right middle lobe of the lung and the heart were harvested for histological and immunohistochemical evaluation on postnatal days 0 and 7. The FGR group exhibited significantly lower body weight, hypertrophy and degeneration of cardiomyocytes, increased intercellular spaces between the cardiomyocytes and collagen deposition, and decreased glycogen deposition and HNK-1 expression compared with the control group on postnatal days 0 and 7. These results suggest that neonates with FGR may have inadequate myocardial reserves, which may cause subsequent cardiovascular compromise in future life. Further studies are required to evaluate the hemodynamic changes in these growth-restricted neonates. [ABSTRACT FROM AUTHOR]

High oxygen concentrations are often required to treat newborn infants with respiratory distress but have adverse effects, such as increased oxidative stress and ferroptosis and impaired alveolarization. Cathelicidins are a family of antimicrobial peptides that exhibit antioxidant activity, and they can reduce hyperoxia-induced oxidative stress. This study evaluated the effects of cathelicidin treatment on lung ferroptosis and alveolarization in hyperoxia-exposed newborn rats. Sprague Dawley rat pups were either reared in room air (RA) or hyperoxia (85% O2) and then randomly given cathelicidin (8 mg/kg) in 0.05 mL of normal saline (NS), or NS was administered intraperitoneally on postnatal days from 1–6. The four groups obtained were as follows: RA + NS, RA + cathelicidin, O2 + NS, and O2 + cathelicidin. On postnatal day 7, lungs were harvested for histological, biochemical, and Western blot analyses. The rats nurtured in hyperoxia and treated with NS exhibited significantly lower body weight and cathelicidin expression, higher Fe2+, malondialdehyde, iron deposition, mitochondrial damage (TOMM20), and interleukin-1β (IL-1β), and significantly lower glutathione, glutathione peroxidase 4, and radial alveolar count (RAC) compared to the rats kept in RA and treated with NS or cathelicidin. Cathelicidin treatment mitigated hyperoxia-induced lung injury, as demonstrated by higher RAC and lower TOMM20 and IL-1β levels. The attenuation of lung injury was accompanied by decreased ferroptosis. These findings indicated that cathelicidin mitigated hyperoxia-induced lung injury in the rats, most likely by inhibiting ferroptosis. [ABSTRACT FROM AUTHOR]

Preclinical studies have demonstrated that intrauterine growth retardation (IUGR) is associated with reduced lung development during the neonatal period and infancy. Uteroplacental insufficiency (UPI), affecting approximately 10% of human pregnancies, is the most common cause of IUGR. This study investigated the effects of UPI on lung development and the intestinal microbiota and correlations in newborn rats with IUGR, using bilateral uterine artery ligation to induce UPI. Maternal fecal samples were collected on postnatal day 0. On postnatal days 0 and 7, lung and intestinal microbiota samples were collected from the left lung and the lower gastrointestinal tract. The right lung was harvested for histological assessment and Western blot analysis. Results showed that UPI through bilateral uterine artery ligation did not alter the maternal gut microbiota. IUGR impaired lung development and angiogenesis in newborn rats. Moreover, on postnatal day 0, the presence of Acinetobacter and Delftia in the lungs and Acinetobacter and Nevskia in the gastrointestinal tract was negatively correlated with lung development. Bacteroides in the lungs and Rodentibacter and Romboutsia in the gastrointestinal tract were negatively correlated with lung development on day 7. UPI may have regulated lung development and angiogenesis through the modulation of the newborn rats' intestinal and lung microbiota. [ABSTRACT FROM AUTHOR]