Nadph oxidase and epithelial sodium channels regulate neonatal mouse lung development
AIMS MOLECULAR SCIENCE
Authors: Trac, David; Helms, My N.
Abstract
Background: Epithelial sodium channels (ENaC) play critically important roles in lung fluid clearance at birth. We have previously shown that Nadph oxidase (NOX)-derived reactive oxygen species signaling activates ENaC and promotes alveolar fluid clearance. In this study, we examined a new physiological role for NOX-mediated ENaC activity in mouse lung development. Methods: NOX isoform and ENaC subunit mRNA levels were evaluated in preterm and neonatal C57Bl6 mouse lung using real-time PCR analysis. Newborn mice were intra-nasally treated with 1 mM amiloride, 100. M NSC 23766, or 300 mu M apocynin during postnatal days 1-15 to study development. Lung development was assessed using hematoxylin and eosin (H&E) staining, coupled with radial alveolar counts (RAC) and mean linear intercept (MLI) measurements. Results: ENaC subunits and NOX1-4 mRNA were detected in mouse lung during late gestation, birth, and postnatally. Inhibition of Rac-1-mediated-NOX signaling indicates functional (Rac-dependent) NOX1-3 isoforms in newborn lung, determined by dihydroethidium (DHE) detection of reactive oxygen species production in postnatal (PN) day 7 mouse lung. Amiloride inhibition of ENaC activity, NSC 23766 inhibition of Rac1, and apocynin inhibition of pan NOX activity attenuated normal alveolar development in mouse lung. Conclusion: NOX and ENaC play important roles in mouse lung development.
Effect of a heme oxygenase-1 inducer on NADPH oxidase expression in alcohol-induced liver injury in male Wistar rats
TROPICAL JOURNAL OF PHARMACEUTICAL RESEARCH
Authors: Koomhin, Phanit; Punsawad, Chuchard; Suwannalert, Prasit; Palipoch, Sarawoot
Abstract
Purpose: To investigated the effect of hemin, a heme oxygenase-1 (HO-1) inducer, on nicotinamide adenine dinucleotide phosphate oxidase (NOX) expression in rats with alcohol-induced liver injury. Methods: Male Wistar rats were randomly divided into four groups consisting of the control group, the ethanol (EtOH) group, the EtOH + zinc protoporphyrin IX (ZnPP-IX) group and EtOH + hemin group. Hepatic NOX gene expression and immunohistochemistry of hepatic NOX1 and NOX4 were investigated in week 4. Results: EtOH significantly increased levels of NOX. An immunohistochemical study demonstrated a high number of immunopositive hepatocytes for NOX1 in the EtOH group and EtOH + ZnPP-IX group compared with the control group. Hemin administration downregulated NOX gene expression and lowered the number of immunopositive hepatocytes for NOX1. In contrast, ZnPP-IX (HO-1 inhibitor) administration caused upregulation of NOX gene expression and increased the number of immunopositive hepatocytes for NOX1. Conclusion: HO-1 inducer, hemin, alleviates oxidative stress-induced alcoholic liver injury by reducing NOX, especially NOX1.