Maternal high fructose and low protein consumption during pregnancy and lactation share some but not all effects on early-life growth and metabolic programming of rat offspring

Maternal Protein Restriction Combined with Postnatal Sugar Consumption Alters Liver Proteomic Profile and Metabolic Pathways in Adult Male Offspring Rats

This study investigated the impact of maternal protein restriction (MPR) and early postnatal sugar consumption (SUG) on the liver health of adult male descendant rats. Male offspring of mothers fed a normal protein diet (NPD) or a low protein diet (LPD) were divided into four groups: Control (CTR), Sugar Control (CTR+SUG), LPD during gestation and lactation (GLLP), and LPD with sugar (GLLP+SUG). Sugar consumption (10% glucose diluted in water) began after weaning on day 21 (PND 21), and at 90 days (PND 90), rats were sacrificed for analysis. Sugar intake reduced food intake and increased water consumption in CTR+SUG and GLLP+SUG compared to CTR and GLLP. GLLP and GLLP+SUG groups showed lower body weight and total and retroperitoneal fat compared to CTR and CTR+SUG. CTR+SUG and GLLP+SUG groups exhibited hepatocyte vacuolization associated with increased hepatic glycogen content compared to CTR and GLLP. Hepatic catalase activity increased in GLLP compared to CTR. Proteomic analysis identified 223 differentially expressed proteins (DEPs) among experimental groups. While in the GLLP group, the DEPs enriched molecular pathways related to cellular stress, glycogen metabolic pathways were enriched in the GLLP+SUG and CTR+SUG groups. The association of sugar consumption amplifies the effects of MPR, deregulating molecular mechanisms related to metabolism and the antioxidant system.

Maternal low protein diet and fetal programming of lean type 2 diabetes

Maternal nutrition is found to be the key factor that determines fetal health in utero and metabolic health during adulthood. Metabolic diseases have been primarily attributed to impaired maternal nutrition during pregnancy, and impaired nutrition has been an immense issue across the globe. In recent years, type 2 diabetes (T2D) has reached epidemic proportion and is a severe public health problem in many countries. Although plenty of research has already been conducted to tackle T2D which is associated with obesity, little is known regarding the etiology and pathophysiology of lean T2D, a variant of T2D. Recent studies have focused on the effects of epigenetic variation on the contribution of in utero origins of lean T2D, although other mechanisms might also contribute to the pathology. Observational studies in humans and experiments in animals strongly suggest an association between maternal low protein diet and lean T2D phenotype. In addition, clear sex-specific disease prevalence was observed in different studies. Consequently, more research is essential for the understanding of the etiology and pathophysiology of lean T2D, which might help to develop better disease prevention and treatment strategies. This review examines the role of protein insufficiency in the maternal diet as the central driver of the developmental programming of lean T2D.

Maternal High-Sucrose Diet Affects Phenotype Outcome in Adult Male Offspring: Role of Zbtb16

Overnutrition in pregnancy and lactation affects fetal and early postnatal development, which can result in metabolic disorders in adulthood. We tested a hypothesis that variation of the Zbtb16 gene, a significant energy metabolism regulator, modulates the effect of maternal high-sucrose diet (HSD) on metabolic and transcriptomic profiles of the offspring. We used the spontaneously hypertensive rat (SHR) strain and a minimal congenic rat strain SHR-Zbtb16, carrying the Zbtb16 gene allele originating from the PD/Cub rat, a metabolic syndrome model. Sixteen-week-old SHR and SHR-Zbtb16 rat dams were fed either standard diet (control groups) or a high-sucrose diet (HSD, 70% calories as sucrose) during pregnancy and 4 weeks of lactation. In dams of both strains, we observed an HSD-induced increase of cholesterol and triacylglycerol concentrations in VLDL particles and a decrease of cholesterol and triacylglycerols content in medium to very small LDL particles. In male offspring, exposure to maternal HSD substantially increased brown fat weight in both strains, decreased triglycerides in LDL particles, and impaired glucose tolerance exclusively in SHR. The transcriptome assessment revealed networks of transcripts reflecting the shifts induced by maternal HSD with major nodes including mir-126, Hsd11b1 in the brown adipose tissue, Pcsk9, Nr0b2 in the liver and Hsd11b1, Slc2a4 in white adipose tissue. In summary, maternal HSD feeding during pregnancy and lactation affected brown fat deposition and lipid metabolism in adult male offspring and induced major transcriptome shifts in liver, white, and brown adipose tissues. The Zbtb16 variation present in the SHR-Zbtb16 led to several strain-specific effects of the maternal HSD, particularly the transcriptomic profile shifts of the adult male offspring.

Maternal low protein exposure alters glucose tolerance and intestinal nutrient-responsive receptors and transporters expression of rat offspring

AIMS

Maternal protein malnutrition during perinatal period has long-term consequences on the offspring's metabolic phenotype. Here we determined the effects of maternal protein-restricted (PR) diet on offspring's metabolism in 3- and 12-week-old.

MAIN METHODS

Sprague-Dawley rats were fed with standard chow diet or PR diet during pregnancy and lactation. Food intake and body weight of offspring were measured weekly. The oral glucose tolerance tests were underwent, the pancreases were collected for histochemical staining, and the duodenum, jejunum and ileum were collected for gene and protein expression analysis in 3- and 12-week-old offspring.

KEY FINDINGS

PR offspring had significant lower body weight and persisted till 12-week-old. From 3- to 12-week-old, PR offspring presented considerably impaired glucose tolerance, while no marked change was shown in control rats. Additionally, the average islet size of PR offspring decreased significantly in 12-week-old. The mRNA and protein expression of nutrient-responsive receptors and transporters T1R3, SGLT1 and GLUT2 increased significantly in the intestine of 3-week-old PR offspring. And from 3- and 12-week-old, the increase tendency of expression subdued.

SIGNIFICANCE

These results suggest that maternal PR diet during critical developmental windows influences offspring metabolism, which may be subdued partially, but not be reversed completely by chow diet after weaning.

Hyperlocomotion Test for Assessing Behavioral Disorders

Under- or overfeeding during pregnancy can lead to behavioral deficits in the offspring in later life. Here, we present a protocol for setting up and carrying out the hyperlocomotion test for assessing behavioral symptoms such as psychosis or mania. As an example, we use the acute rat phencyclidine-injection model which exhibits hyperlocomotion and stereotypic behaviors, resembling the positive symptoms of schizophrenia.