Effects of Maternal Exposure to Cadmium Oxide Nanoparticles During Pregnancy on Maternal and Offspring Kidney Injury Markers Using a Murine Model

Abstract

Nanoparticles (NP) are pervasive in many areas of modern life, with little known about their potential toxicities. One commercially important NP is cadmium oxide (CdO), which is used to synthesize other Cd-containing NP, such as quantum dots. Cadmium (Cd) is a well-known nephrotoxicant, but the nephrotoxic potential of CdO NP remains unknown, particularly when exposure occurs during pregnancy. Therefore, pregnant CD-1 mice were used to examine the effects of inhaled CdO NP (230 μg CdO NP/m3) on maternal and neonatal renal function by examining urinary creatinine and urinary biomarkers of kidney injury, including kidney injury molecule-1 (Kim-1) and neutrophil gelatinase-associated lipocalin (NGAL). Inhalation of CdO NP by dams produced a fivefold increase in urinary Kim-1 with no marked effect on urinary creatinine levels. Kim-1 mRNA expression peaked by gestational day (GD) 10.5, and NGAL expression increased from GD 10.5 to 17.5. In addition, histological analyses revealed proximal tubular pathology at GD 10.5. Neonatal Kim-1 mRNA expression rose between postnatal days (PND) 7 and 14, with mammary glands/milk being the apparent source of Cd for offspring. These studies demonstrate that, similar to what is seen with other Cd forms, Cd associated with inhaled CdO NP results in renal injury to both directly exposed dam and offspring. As commercial uses for nanotechnology continue to expand throughout the world, risks for unintentional exposure in the workplace increase. Given the large number of women in the industrial workforce, care needs to be taken to protect these already vulnerable populations.