Prenatal exposure to hypoxia induced beclin 1 signaling-mediated renal autophagy and altered renal development in rat fetuses

Abstract

Aims: Hypoxia has adverse effects on renal development. This study was the first to test hypoxia-induced renal autophagy in rat fetuses. Methods: Pregnant rats were exposed to hypoxia or normoxia during pregnancy and fetal kidneys were collected at gestation day 21. Results: Fetal kidney weight and ratio of kidney-body weight were reduced. Histological analysis showed enlargement in Bowman space and wider space between interstitia in the kidneys of fetus exposed to hypoxia. Fetal renal B-cell lymphoma 2 (BCL-2) was decreased accompanied with higher 2′-deoxyuridine 5′-triphosphate nick end-labeling staining and unchanged soluble FAS in the hypoxia group. Hypoxia increased autophagic structures, including autophagosomes and autolysosomes, in fetal kidneys and increased renal APG5L. There was an increase in renal LC3-II, Beclin 1, p-S6, hypoxia inducible factor 1a (HIF-1a), and ratio of LC3-II-LC3-I and a decrease in P62, protein kinase B (AKT), and phosphorylated AKT in the hypoxia group. Both renal mammalian target of rapamycin (mTOR) and Beclin 1 signaling were upregulated. Conclusion: Hypoxia-affected fetal renal development was associated with renal apoptosis and Beclin 1 signaling-mediated autophagy.