Intergenerational response of steroidogenesis-related genes to maternal malnutrition

Involvement of Autophagy and Oxidative Stress-Mediated DNA Hypomethylation in Transgenerational Nephrotoxicity Induced in Rats by the Mycotoxin Fumonisin B1

Fumonisin B1 (FB1), a mycotoxin produced by Fusarium verticillioides, is one of the most common pollutants in natural foods and agricultural crops. It can cause chronic and severe health issues in humans and animals. The aim of this study was to evaluate the transgenerational effects of FB1 exposure on the structure and function of the kidneys in offspring. Virgin female Wistar rats were randomly divided into three groups: group one (control) received sterile water, and groups two and three were intragastrically administered low (20 mg/kg) and high (50 mg/kg) doses of FB1, respectively, from day 6 of pregnancy until delivery. Our results showed that exposure to either dose of FB1 caused histopathological changes, such as atrophy, hypercellularity, hemorrhage, calcification, and a decrease in the glomerular diameter, in both the first and second generations. The levels of the antioxidant markers glutathione, glutathione S-transferase, and catalase significantly decreased, while malondialdehyde levels increased. Moreover, autophagy was induced, as immunofluorescence analysis revealed that LC-3 protein expression was significantly increased in both generations after exposure to either dose of FB1. However, a significant decrease in methyltransferase (DNMT3) protein expression was observed in the first generation in both treatment groups (20 mg/kg and 50 mg/kg), indicating a decrease in DNA methylation as a result of early-life exposure to FB1. Interestingly, global hypomethylation was also observed in the second generation in both treatment groups despite the fact that the mothers of these rats were not exposed to FB1. Thus, early-life exposure to FB1 induced nephrotoxicity in offspring of the first and second generations. The mechanisms of action underlying this transgenerational effect may include oxidative stress, autophagy, and DNA hypomethylation.

Long-Term but Not Short-Term Maternal Fasting Reduces Nephron Number and Alters the Glomerular Filtration Barrier in Rat Offspring

The present study examined the effects of maternal Ramadan-type fasting during selected days in the first, second, or third trimester, or during the entire pregnancy, on the kidney structure of male rat offspring. Pregnant rats were provided with food ad libitum during pregnancy (control group, C), or they were exposed to 16 h of fasting/day for three consecutive days in the middle of the first (FT1), second (FT2), or third trimester (FT3), or during whole pregnancy (FWP). Our results showed that dams in the FWP group demonstrated lower food intake and body weight during gestation. Litter size was unaltered by fasting in all groups; however, litter weight was significantly reduced only in the FWP group. Nephron number was decreased in the FWP group, but it remained unchanged in the other fasting groups. The ultrastructure of the glomerular filtration barrier indicated that the kidneys of offspring of the FWP group demonstrated wider diameters of fenestrations and filtration slits and smaller diameters of basement membranes. This was reflected by a significant increase in proteinuria in FWP only. These results suggest that, unlike with short-term fasting, which seems to be safe, maternal long-term fasting induces structural changes that were non-reversible, and that may contribute to impaired renal function, leading to chronic diseases in later life.