Maternal Low-protein Diet Alters Ovarian Expression of Folliculogenic and Steroidogenic Genes and Their Regulatory MicroRNAs in Neonatal Piglets

Abstract

Maternal malnutrition during pregnancy may give rise to female offspring with disrupted ovary functions in adult age. Neonatal ovary development predisposes adult ovary function, yet the effect of maternal nutrition on the neonatal ovary has not been described. Therefore, here we show the impact of maternal protein restriction on the expression of folliculogenic and steroidogenic genes, their regulatory microRNAs and promoter DNA methylation in the ovary of neonatal piglets. Sows were fed either standard-protein (SP, 15% crude protein) or low-protein (LP, 7.5% crude protein) diets throughout gestation. Female piglets born to LP sows showed significantly decreased ovary weight relative to body weight (p<0.05) at birth, which was accompanied with an increased serum estradiol level (p<0.05). The LP piglets demonstrated higher ratio of bcl-2 associated X protein/B cell lymphoma/leukemia-2 mRNA (p<0.01), which was associated with up-regulated mRNA expression of bone morphogenic protein 4 (BMP4) (p<0.05) and proliferating cell nuclear antigen (PCNA) (p<0.05). The steroidogenic gene, cytochrome P450 aromatase (CYP19A1) was significantly down-regulated (p<0.05) in LP piglets. The alterations in ovarian gene expression were associated with a significant down-regulation of follicle-stimulating hormone receptor mRNA expression (p<0.05) in LP piglets. Moreover, three microRNAs, including miR-423-5p targeting both CYP19A1 and PCNA, miR-378 targeting CYP19A1 and miR-210 targeting BMP4, were significantly down-regulated (p<0.05) in the ovary of LP piglets. These results suggest that microRNAs are involved in mediating the effect of maternal protein restriction on ovarian function through regulating the expression of folliculogenic and steroidogenic genes in newborn piglets.

An integrated analysis of the circRNA–miRNA–mRNA network reveals novel insights into potential mechanisms of cell proliferation during liver regeneration

“…According to the prediction results shown in Figure 4 and Table 3, only circ_19698 and rno-miR-423-5p clearly and uniquely exhibited regulatory relationships between all the circRNA-miRNA pairs, although rno-miR-423-5p could regulate the expressions of two target genes, including Myc and Pcna. Furthermore, there have been several studies that demonstrated the targets of miR-423-5p [41], which assisted with verifying and comparing our results to other studies. Therefore, the circ_19698/miR-423-5p axis may positively regulate cell proliferation during LR, which was then was selected for the further functional validation of the ceRNA regulatory network in vitro.…”

Roles of microRNAs in mammalian reproduction: from the commitment of germ cells to peri‐implantation embryos

“…In pigs, miR‐34a and miR‐26b target INHBB and SMAD4 , respectively, and negatively regulate the steroidogenic process by promoting the apoptosis of GCs (Liu et al, ; Tu et al, ). Similarly, miR‐423‐5p and miR‐378 post‐transcriptionally downregulate CYP19A1 (Xu et al, ; Sui et al, ) and miR‐375 binds to the 3′ untranslated region of specificity protein 1 ( SP1 ) and mediates corticotropin releasing hormone ( CRH ) signalling (Yu et al, ): these miRNAs directly regulate oestradiol synthesis in porcine GCs. In mice, miR‐224 enhances Tgfβ‐induced proliferation of GCs by targeting Smad4 and promotes oestradiol biogenesis by increasing Cyp19a1 (Yao et al, ).…”

Testicular development in male lambs prenatally exposed to a high‐starch diet

“…Although a global maternal nutrient imbalance (restriction or excess) can program the offspring phenotype, the diet composition during pregnancy may also have effects on the progeny (Indrio et al, ). For example, evidence indicates that maternal isocaloric diets with different protein composition may impact differently on offspring reproductive development (Sui, He, et al, ; Sui, Jia, et al, ; Zambrano et al, ). Newborn female piglets born to mothers exposed to protein restriction throughout gestation had lighter ovaries, higher circulating estradiol concentrations, greater expression of genes involved in folliculogenesis ( BAX/Bcl‐2, BMP4, PCNA) and lower mRNA abundancy of steroidogenic genes ( FSHR and CYP19A1 ) in the ovaries, as compared to offspring of sows fed an isocaloric diet with higher protein content (Sui, Jia, et al, ).…”

“…For example, evidence indicates that maternal isocaloric diets with different protein composition may impact differently on offspring reproductive development (Sui, He, et al, ; Sui, Jia, et al, ; Zambrano et al, ). Newborn female piglets born to mothers exposed to protein restriction throughout gestation had lighter ovaries, higher circulating estradiol concentrations, greater expression of genes involved in folliculogenesis ( BAX/Bcl‐2, BMP4, PCNA) and lower mRNA abundancy of steroidogenic genes ( FSHR and CYP19A1 ) in the ovaries, as compared to offspring of sows fed an isocaloric diet with higher protein content (Sui, Jia, et al, ). In addition, maternal low protein diet during gestation and lactation disrupted the ovarian follicular development in prepubertal (6‐month‐old) gilts, as assessed by a decrease in the number of primordial and Graafian follicles associated with an increased number of secondary follicles (Sui, He, et al, ).…”