Impact of maternal overweight on the sexual maturity of male offspring in rats

Maternal cafeteria diet influences kisspeptin (Kiss1), kisspeptin receptor(Gpr54), and sirtuin (Sirt1) genes, hormonal and metabolic profiles, and reproductive functions in rat offspring in a sex-specific manner†

Kisspeptin (KP, encoded by Kiss1, binding to the Gpr54 receptor) is a neuropeptide conveying information on the metabolic status to the hypothalamic-pituitary-gonadal axis. KP acts together with dynorphin A (encoded by Pdyn) and neurokinin B (encoded by Tac2) to regulate reproduction. KP is crucial for the onset of puberty and is under the control of sirtuin (encoded by Sirt1). We hypothesize that the maternal cafeteria (CAF) diet has adverse effects on the offspring's hormonal, metabolic, and reproductive functions due to sex-specific alterations in the expression of Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 in the hypothalamus, and Kiss1, Gpr54, and Sirt1 in the liver. Rats were fed a CAF diet before pregnancy, during pregnancy, and during lactation. The vaginal opening was monitored. Offspring were sacrificed in three age points: PND 30, PND 35, and PND 60 (females) and PND 40, PND 45, and PND 60 (males). Their metabolic and hormonal status was assessed. mRNA for Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 were measured by real-time PCR in the hypothalamus and/or livers. We found that CAF offspring had lower weight and altered body composition; increased cholesterol and triglyceride levels, sex-specific changes in glucose and insulin levels; sex-dependent changes in Sirt1/Kiss1 mRNA ratio in the hypothalamus; sex-specific alterations in Kiss1 and Sirt1 mRNA in the liver with more diversity in males; and a delayed puberty onset in females. We concluded that the mother's CAF diet leads to sex-specific alterations in metabolic and reproductive outcomes via Kiss1/Gpr54 and Sirt1 systems in offspring.

Different prenatal supplementation strategies and its impacts on reproductive and nutrigenetics assessments of bulls in finishing phase

This study investigated the effect of different prenatal nutrition approaches in 126 pregnant Nellore cows on reproductive and nutrigenetic traits of the male offspring during the finishing phase. For that purpose, three nutritional treatments were used in these cows during pregnancy: PP - protein-energy supplementation in the final third, FP - protein-energy supplementation during the entire pregnancy, and NP - (control) only mineral supplementation. The male progeny (63 bulls; 665 ± 28 days of age) were evaluated for scrotal circumference, seminal traits, number of Sertoli cells and testicular area. We performed a genomic association (700 K SNPs) for scrotal circumference at this age. In addition, a functional enrichment was performed in search of significant metabolic pathways (P < 0.05) with inclusion of genes that are expressed in these genomic windows by the MetaCore software. With the exception of major sperm defects (P < 0.1), the other phenotypes showed no difference between prenatal treatments. We found genes and metabolic pathways (P < 0.05) that are associated with genomic windows (genetic variance explained >1%) in different treatments. These molecular findings indicate that there is genotype-environment interaction among the different prenatal treatments and that the FP treatment showed greater major sperm defects compared to the NP treatment.

Diet-induced maternal obesity and overnutrition cause a decrease in the sperm quality of the offspring

The present work aimed to study the changes caused by maternal obesity and overnutrition in both the quality and function of spermatozoa of the offspring. To this end, female rats received either a standard (SD) or cafeteria (CD) diet from 22 days of age until the weaning of their offspring, and the male offspring (OSD and OCD respectively) were used. Different endpoints in the offspring, as body weight, weight gain and glycemia were recorded and the testes were removed at 60 days of age. Different spermatozoa parameters, such as mitochondrial function, functional integrity of the sperm plasma membrane, capacitation, and acrosome status, were evaluated. The OCD group was heavier than the OSD group and exhibited lower testis and epididymal indices. The OCD group also showed a decrease in the ability of the sperm tail to react in the presence of a hypoosmotic solution, deficiency in sperm mitochondrial function, a lower percentage of spermatozoa without acrosome when exposed to a capacitation medium, and a higher number of abnormal metaphases. In addition, compared with OSD, OCD rats had a higher number of TUNEL-positive cells in the histological sections of the testis, and greater presence of reactive oxygen species in the spermatozoa, evaluated by a fluorescent probe. However, the OCD group displayed lower protein levels of cytochrome c and caspase-3 in testis tissue than the control group. These results suggest that maternal obesity and overnutrition program the offspring to develop poor sperm quality and function, which may imply a condition of subfertility.