Characterizing Early Cardiac Metabolic Programming via 30% Maternal Nutrient Reduction during Fetal Development in a Non-Human Primate Model.

Intra-uterine growth restriction (IUGR) is a common cause of fetal/neonatal morbidity and mortality and is associated with increased offspring predisposition for cardiovascular disease (CVD) development. Mitochondria are essential organelles in maintaining cardiac function, and thus, fetal cardiac mitochondria could be responsive to the IUGR environment. In this study, we investigated whether in utero fetal cardiac mitochondrial programming can be detectable in an early stage of IUGR pregnancy. Using a well-established nonhuman IUGR primate model, we induced IUGR by reducing by 30% the maternal diet (MNR), both in males (MNR-M) and in female (MNR-F) fetuses. Fetal cardiac left ventricle (LV) tissue and blood were collected at 90 days of gestation (0.5 gestation, 0.5 G). Blood biochemical parameters were determined and heart LV mitochondrial biology assessed. MNR fetus biochemical blood parameters confirm an early fetal response to MNR. In addition, we show that in utero cardiac mitochondrial MNR adaptations are already detectable at this early stage, in a sex-divergent way. MNR induced alterations in the cardiac gene expression of oxidative phosphorylation (OXPHOS) subunits (mostly for complex-I, III, and ATP synthase), along with increased protein content for complex-I, -III, and -IV subunits only for MNR-M in comparison with male controls, highlight the fetal cardiac sex-divergent response to MNR. At this fetal stage, no major alterations were detected in mitochondrial DNA copy number nor markers for oxidative stress. This study shows that in 90-day nonhuman primate fetuses, a 30% decrease in maternal nutrition generated early in utero adaptations in fetal blood biochemical parameters and sex-specific alterations in cardiac left ventricle gene and protein expression profiles, affecting predominantly OXPHOS subunits. Since the OXPHOS system is determinant for energy production in mitochondria, our findings suggest that these early IUGR-induced mitochondrial adaptations play a role in offspring's mitochondrial dysfunction and can increase predisposition to CVD in a sex-specific way.

Postnatal persistence of nonhuman primate sex-dependent renal structural and molecular changes programmed by intrauterine growth restriction.

BACKGROUND: Poor nutrition during fetal development programs postnatal kidney function. Understanding postnatal consequences in nonhuman primates (NHP) is important for translation to our understanding the impact on human kidney function and disease risk. We hypothesized that intrauterine growth restriction (IUGR) in NHP persists postnatally, with potential molecular mechanisms revealed by Western-type diet challenge. METHODS: IUGR juvenile baboons were fed a 7-week Western diet, with kidney biopsies, blood, and urine collected before and after challenge. Transcriptomics and metabolomics were used to analyze biosamples. RESULTS: Pre-challenge IUGR kidney transcriptome and urine metabolome differed from controls. Post-challenge, sex and diet-specific responses in urine metabolite and renal signaling pathways were observed. Dysregulated mTOR signaling persisted postnatally in female pre-challenge. Post-challenge IUGR male response showed uncoordinated signaling suggesting proximal tubule injury. CONCLUSION: Fetal undernutrition impacts juvenile offspring kidneys at the molecular level suggesting early-onset blood pressure dysregulation.

Sex-dependent vulnerability of fetal nonhuman primate cardiac mitochondria to moderate maternal nutrient reduction.

Poor maternal nutrition in pregnancy affects fetal development, predisposing offspring to cardiometabolic diseases. The role of mitochondria during fetal development on later-life cardiac dysfunction caused by maternal nutrient reduction (MNR) remains unexplored. We hypothesized that MNR during gestation causes fetal cardiac bioenergetic deficits, compromising cardiac mitochondrial metabolism and reserve capacity. To enable human translation, we developed a primate baboon model (Papio spp.) of moderate MNR in which mothers receive 70% of control nutrition during pregnancy, resulting in intrauterine growth restriction (IUGR) offspring and later exhibiting myocardial remodeling and heart failure at human equivalent ∼25 years. Term control and MNR baboon offspring were necropsied following cesarean-section, and left ventricle (LV) samples were collected. MNR adversely impacted fetal cardiac LV mitochondria in a sex-dependent fashion. Increased maternal plasma aspartate aminotransferase, creatine phosphokinase (CPK), and elevated cortisol levels in MNR concomitant with decreased blood insulin in male fetal MNR were measured. MNR resulted in a two-fold increase in fetal LV mitochondrial DNA (mtDNA). MNR resulted in increased transcripts for several respiratory chain (NDUFB8, UQCRC1, and cytochrome c) and adenosine triphosphate (ATP) synthase proteins. However, MNR fetal LV mitochondrial complex I and complex II/III activities were significantly decreased, possibly contributing to the 73% decreased ATP content and increased lipid peroxidation. MNR fetal LV showed mitochondria with sparse and disarranged cristae dysmorphology. Conclusion: MNR disruption of fetal cardiac mitochondrial fitness likely contributes to the documented developmental programming of adult cardiac dysfunction, indicating a programmed mitochondrial inability to deliver sufficient energy to cardiac tissues as a chronic mechanism for later-life heart failure.

Maternal activity, anxiety, and protectiveness during moderate nutrient restriction in captive baboons (Papio sp.).

BACKGROUND: We hypothesized that maternal nutrient restriction (NR) would increase activity and behavioral indicators of anxiety (self-directed behaviors, SDBs) in captive baboons (Papio sp.) and result in more protective maternal styles. METHODS: Our study included 19 adult female baboons. Seven females ate ad libitum (control group), and eight females ate 30% less (NR group) and were observed through pregnancy and lactation. RESULTS: Control females engage in higher rates of SDB than NR females overall (P ≤ .018) and during the prenatal period (P ≤ .001) and engage in more aggressive behavior (P ≤ .033). Control females retrieved infants more than NR females during weeks 5-8 postpartum (P ≤ .019). CONCLUSIONS: Lower SDB rates among prenatal NR females reduce energy expenditure and increase available resources for fetal development when nutritionally restricted. Higher infant retrieval rates by controls may indicate more infant independence rather than maternal style differences.

The non-human primate kidney transcriptome in fetal development.

BACKGROUND: Little is known about the repertoire of non-human primate kidney genes expressed throughout development. The present work establishes an understanding of the primate renal transcriptome during fetal development in the context of renal maturation. METHODS: The baboon kidney transcriptome was characterized at 60-day gestation (DG), 90 DG, 125 DG, 140 DG, 160 DG and adulthood (6-12 years) using gene arrays and validated by QRT-PCR. Pathway and cluster analyses were used to characterize gene expression in the context of biological pathways. RESULTS: Pathway analysis indicated activation of pathways not previously reported as relevant to kidney development. Cluster analysis also revealed gene splice variants with discordant expression profiles during development. CONCLUSIONS: This study provides the first detailed genetic analysis of the developing primate kidney, and our findings of discordant expression of gene splice variants suggest that gene arrays likely provide a simplified view and demonstrate the need to study the fetal renal proteome.

Role of catecholamines in maternal-fetal stress transfer in sheep.

OBJECTIVE: We sought to evaluate whether in addition to cortisol, catecholamines also transfer psychosocial stress indirectly to the fetus by decreasing uterine blood flow (UBF) and increasing fetal anaerobic metabolism and stress hormones. STUDY DESIGN: Seven pregnant sheep chronically instrumented with uterine ultrasound flow probes and catheters at 0.77 gestation underwent 2 hours of psychosocial stress by isolation. We used adrenergic blockade with labetalol to examine whether decreased UBF is catecholamine mediated and to determine to what extent stress transfer from mother to fetus is catecholamine dependent. RESULTS: Stress induced transient increases in maternal cortisol and norepinephrine (NE). Maximum fetal plasma cortisol concentrations were 8.1 ± 2.1% of those in the mother suggesting its maternal origin. In parallel to the maternal NE increase, UBF decreased by maximum 22% for 30 minutes (P < .05). Fetal NE remained elevated for >2 hours accompanied by a prolonged blood pressure increase (P < .05). Fetuses developed a delayed and prolonged shift toward anaerobic metabolism in the presence of an unaltered oxygen supply. Adrenergic blockade prevented the stress-induced UBF decrease and, consequently, the fetal NE and blood pressure increase and the shift toward anaerobic metabolism. CONCLUSION: We conclude that catecholamine-induced decrease of UBF is a mechanism of maternal-fetal stress transfer. It may explain the influence of maternal stress on fetal development and on programming of adverse health outcomes in later life especially during early pregnancy when fetal glucocorticoid receptor expression is limited.

Back to the future: transgenerational transmission of xenobiotic-induced epigenetic remodeling.

Epigenetics, or regulation of gene expression independent of DNA sequence, is the missing link between genotype and phenotype. Epigenetic memory, mediated by histone and DNA modifications, is controlled by a set of specialized enzymes, metabolite availability, and signaling pathways. A mostly unstudied subject is how sub-toxic exposure to several xenobiotics during specific developmental stages can alter the epigenome and contribute to the development of disease phenotypes later in life. Furthermore, it has been shown that exposure to low-dose xenobiotics can also result in further epigenetic remodeling in the germ line and contribute to increase disease risk in the next generation (multigenerational and transgenerational effects). We here offer a perspective on current but still incomplete knowledge of xenobiotic-induced epigenetic alterations, and their possible transgenerational transmission. We also propose several molecular mechanisms by which the epigenetic landscape may be altered by environmental xenobiotics and hypothesize how diet and physical activity may counteract epigenetic alterations.

Effects of moderate global maternal nutrient reduction on fetal baboon renal mitochondrial gene expression at 0.9 gestation.

Early life malnutrition results in structural alterations in the kidney, predisposing offspring to later life renal dysfunction. Kidneys of adults who were growth restricted at birth have substantial variations in nephron endowment. Animal models have indicated renal structural and functional consequences in offspring exposed to suboptimal intrauterine nutrition. Mitochondrial bioenergetics play a key role in renal energy metabolism, growth, and function. We hypothesized that moderate maternal nutrient reduction (MNR) would adversely impact fetal renal mitochondrial expression in a well-established nonhuman primate model that produces intrauterine growth reduction at term. Female baboons were fed normal chow diet or 70% of control diet (MNR). Fetal kidneys were harvested at cesarean section at 0.9 gestation (165 days gestation). Human Mitochondrial Energy Metabolism and Human Mitochondria Pathway PCR Arrays were used to analyze mitochondrially relevant mRNA expression. In situ protein content was detected by immunohistochemistry. Despite the smaller overall size, the fetal kidney weight-to-body weight ratio was not affected. We demonstrated fetal sex-specific differential mRNA expression encoding mitochondrial metabolite transport and dynamics proteins. MNR-related differential gene expression was more evident in female fetuses, with 16 transcripts significantly altered, including 14 downregulated and 2 upregulated transcripts. MNR impacted 10 transcripts in male fetuses, with 7 downregulated and 3 upregulated transcripts. The alteration in mRNA levels was accompanied by a decrease in mitochondrial protein cytochrome c oxidase subunit VIc. In conclusion, transcripts encoding fetal renal mitochondrial energy metabolism proteins are nutrition sensitive in a sex-dependent manner. We speculate that these differences lead to decreased mitochondrial fitness that contributes to renal dysfunction in later life.

Down-regulation of placental mTOR, insulin/IGF-I signaling, and nutrient transporters in response to maternal nutrient restriction in the baboon.

The mechanisms by which maternal nutrient restriction (MNR) causes reduced fetal growth are poorly understood. We hypothesized that MNR inhibits placental mechanistic target of rapamycin (mTOR) and insulin/IGF-I signaling, down-regulates placental nutrient transporters, and decreases fetal amino acid levels. Pregnant baboons were fed control (ad libitum, n=11) or an MNR diet (70% of controls, n=11) from gestational day (GD) 30. Placenta and umbilical blood were collected at GD 165. Western blot was used to determine the phosphorylation of proteins in the mTOR, insulin/IGF-I, ERK1/2, and GSK-3 signaling pathways in placental homogenates and expression of glucose transporter 1 (GLUT-1), taurine transporter (TAUT), sodium-dependent neutral amino acid transporter (SNAT), and large neutral amino acid transporter (LAT) isoforms in syncytiotrophoblast microvillous membranes (MVMs). MNR reduced fetal weights by 13%, lowered fetal plasma concentrations of essential amino acids, and decreased the phosphorylation of placental S6K, S6 ribosomal protein, 4E-BP1, IRS-1, Akt, ERK-1/2, and GSK-3. MVM protein expression of GLUT-1, TAUT, SNAT-2 and LAT-1/2 was reduced in MNR. This is the first study in primates exploring placental responses to maternal undernutrition. Inhibition of placental mTOR and insulin/IGF-I signaling resulting in down-regulation of placental nutrient transporters may link maternal undernutrition to restricted fetal growth.

Identification and comparative analyses of myocardial miRNAs involved in the fetal response to maternal obesity.

Human and animal studies show that suboptimal intrauterine environments lead to fetal programming, predisposing offspring to disease in later life. Maternal obesity has been shown to program offspring for cardiovascular disease (CVD), diabetes, and obesity. MicroRNAs (miRNAs) are small, noncoding RNA molecules that act as key regulators of numerous cellular processes. Compelling evidence links miRNAs to the control of cardiac development and etiology of cardiac pathology; however, little is known about their role in the fetal cardiac response to maternal obesity. Our aim was to sequence and profile the cardiac miRNAs that are dysregulated in the hearts of baboon fetuses born to high fat/high fructose-diet (HFD) fed mothers for comparison with fetal hearts from mothers eating a regular diet. Eighty miRNAs were differentially expressed. Of those, 55 miRNAs were upregulated and 25 downregulated with HFD. Twenty-two miRNAs were mapped to human; 14 of these miRNAs were previously reported to be dysregulated in experimental or human CVD. We used an Ingenuity Pathway Analysis to integrate miRNA profiling and bioinformatics predictions to determine miRNA-regulated processes and genes potentially involved in fetal programming. We found a correlation between miRNA expression and putative gene targets involved in developmental disorders and CVD. Cellular death, growth, and proliferation were the most affected cellular functions in response to maternal obesity. Thus, the current study reveals significant alterations in cardiac miRNA expression in the fetus of obese baboons. The epigenetic modifications caused by adverse prenatal environment may represent one of the mechanisms underlying fetal programming of CVD.

Up-regulation of the fetal baboon hypothalamo-pituitary-adrenal axis in intrauterine growth restriction: coincidence with hypothalamic glucocorticoid receptor insensitivity and leptin receptor down-regulation.

Intrauterine growth restriction (IUGR) is an important fetal developmental problem resulting from 2 broad causes: maternal undernutrition and/or decreased fetal nutrient delivery to the fetus via placental insufficiency. IUGR is often accompanied by up-regulation of the hypothalamo-pituitary-adrenal axis (HPAA). Sheep studies show fetal HPAA autonomy in late gestation. We hypothesized that IUGR, resulting from poor fetal nutrient delivery, up-regulates the fetal baboon HPAA in late gestation, driven by hypothalamo-pituitary glucocorticoid receptor (GR) insensitivity and decreased fetal leptin in peripheral plasma. Maternal baboons were fed as ad libitum controls or nutrient restricted to produce IUGR (fed 70% of the control diet) from 0.16 to 0.9 gestation. Peripheral ACTH, cortisol, and leptin were measured by immunoassays. CRH, arginine vasopressin (AVP), GR, leptin receptor (ObRb), and pro-opiomelanocortin peptide expression were determined immunohistochemically. IUGR fetal peripheral cortisol and ACTH, but not leptin, were increased (P < .05). IUGR increased CRH peptide expression, but not AVP, in the fetal hypothalamic paraventricular nucleus (PVN) and median eminence (P < .05). PVN ObRb peptide expression, but not GR, was decreased (P < .05) with IUGR. ObRb and pro-opiomelanocortin were robustly expressed in the anterior pituitary gland, but ∼1% of cells showed colocalization. We conclude that (1) CRH, not AVP, is the major releasing hormone driving ACTH and cortisol secretion during primate IUGR, (2) fetal HPAA activation was aided by GR insensitivity and decreased ObRb expression in the PVN, and (3) the anterior pituitary is not a site for ObRb effects on the HPAA.

Intrauterine growth restriction alters term fetal baboon hypothalamic appetitive peptide balance.

Neurons controlling appetite are located in the hypothalamic arcuate nuclei (ARH). Offspring appetite regulation has been shown to be modified by dysregulation of ARH nuclear development. Most ARH developmental studies have been in altricial rodents whose hypothalamic development is predominantly postnatal. In primates including humans, much development of hypothalamic appetite regulatory centers occurs before birth. We hypothesized that i) appetitive peptides are abundantly expressed by 90 percent gestation (0.9G), ready for postnatal function; ii) by 0.9G, intrauterine growth restriction (IUGR) increases the orexigenic:anorexigenic peptide ratio; iii) IUGR increases fetal glucocorticoid receptor (GR) expression; and iv) IUGR decreases STAT3, which signals inhibition of appetite. We developed a fetal baboon IUGR model resulting from reduced maternal nutrition. Pregnant baboons were fed ad libitum, controls (CTR; n=24), or 70% CTR diet to produce IUGR (n=14). C-section was performed at 0.9G. In CTR (n=7) and IUGR (n=6) fetal brains, ARH appetite regulatory peptides (neuropeptide Y (NPY) and proopiomelanocortin (POMC)) were quantified immunohistochemically. Fetal plasma cortisol was raised in IUGR fetuses. We observed that NPY and POMC were well expressed by 0.9G. IUGR increased NPY, GR, and active phosphorylated GR and decreased POMC and phosphorylated form of STAT3. We conclude that IUGR dysregulates ARH development in ways that will reset the appetitive neuropeptide balance in favor of increased appetite drive in postnatal life. We postulate that changes in peptide abundance are in part due to increased fetal cortisol and ARH GR. These changes may contribute to predisposition to obesity in IUGR offspring.

Effect of 30% nutrient restriction in the first half of gestation on maternal and fetal baboon serum amino acid concentrations.

Mechanisms linking maternal nutrient restriction (MNR) to intra-uterine growth restriction (IUGR) and programming of adult disease remain to be established. The impact of controlled MNR on maternal and fetal amino acid metabolism has not been studied in non-human primates. We hypothesised that MNR in pregnant baboons decreases fetal amino acid availability by mid-gestation. We determined maternal and fetal circulating amino acid concentrations at 90 d gestation (90dG, term 184dG) in control baboons fed ad libitum (C, n 8) or 70% of C (MNR, n 6). Before pregnancy, C and MNR body weights and circulating amino acids were similar. At 90dG, MNR mothers had lower body weight than C mothers (P< 0·05). Fetal and placental weights were similar between the groups. MNR reduced maternal blood urea N (BUN), fetal BUN and fetal BUN:creatinine. Except for histidine and lysine in the C and MNR groups and glutamine in the MNR group, circulating concentrations of all amino acids were lower at 90dG compared with pre-pregnancy. Maternal circulating amino acids at 90dG were similar in the MNR and C groups. In contrast, MNR fetal ß-alanine, glycine and taurine all increased. In conclusion, maternal circulating amino acids were maintained at normal levels and fetal amino acid availability was not impaired in response to 30% global MNR in pregnant baboons. However, MNR weight gain was reduced, suggesting adaptation in maternal-fetal resource allocation in an attempt to maintain normal fetal growth. We speculate that these adaptive mechanisms may fail later in gestation when fetal nutrient demands increase rapidly, resulting in IUGR.

A genome resource to address mechanisms of developmental programming: determination of the fetal sheep heart transcriptome.

The pregnant sheep has provided seminal insights into reproduction related to animal and human development (ovarian function, fertility, implantation, fetal growth, parturition and lactation). Fetal sheep physiology has been extensively studied since 1950, contributing significantly to the basis for our understanding of many aspects of fetal development and behaviour that remain in use in clinical practice today. Understanding mechanisms requires the combination of systems approaches uniquely available in fetal sheep with the power of genomic studies. Absence of the full range of sheep genomic resources has limited the full realization of the power of this model, impeding progress in emerging areas of pregnancy biology such as developmental programming. We have examined the expressed fetal sheep heart transcriptome using high-throughput sequencing technologies. In so doing we identified 36,737 novel transcripts and describe genes, gene variants and pathways relevant to fundamental developmental mechanisms. Genes with the highest expression levels and with novel exons in the fetal heart transcriptome are known to play central roles in muscle development. We show that high-throughput sequencing methods can generate extensive transcriptome information in the absence of an assembled and annotated genome for that species. The gene sequence data obtained provide a unique genomic resource for sheep specific genetic technology development and, combined with the polymorphism data, augment annotation and assembly of the sheep genome. In addition, identification and pathway analysis of novel fetal sheep heart transcriptome splice variants is a first step towards revealing mechanisms of genetic variation and gene environment interactions during fetal heart development.

Sex-dependent cognitive performance in baboon offspring following maternal caloric restriction in pregnancy and lactation.

In humans a suboptimal diet during development has negative outcomes in offspring. We investigated the behavioral outcomes in baboons born to mothers undergoing moderate maternal nutrient restriction (MNR). Maternal nutrient restriction mothers (n = 7) were fed 70% of food eaten by controls (CTR, n = 12) fed ad libitum throughout gestation and lactation. At 3.3 ± 0.2 (mean ± standard error of the mean [SEM]) years of age offspring (controls: female [FC, n = 8], male [MC, n = 4]; nutrient restricted: female [FR, n = 3] and male [MR, n = 4]) were administered progressive ratio, simple discrimination, intra-/extra-dimension set shift and delayed matching to sample tasks to assess motivation, learning, attention, and working memory, respectively. A treatment effect was observed in MNR offspring who demonstrated less motivation and impaired working memory. Nutrient-restricted female offspring showed improved learning, while MR offspring showed impaired learning and attentional set shifting and increased impulsivity. In summary, 30% restriction in maternal caloric intake has long lasting neurobehavioral outcomes in adolescent male baboon offspring.

Prenatal betamethasone exposure has sex specific effects in reversal learning and attention in juvenile baboons.

OBJECTIVE: We investigated effects of 3 weekly courses of fetal betamethasone (ßM) on motivation and cognition in juvenile baboon offspring utilizing the Cambridge Neuropsychological Test Automated Battery. STUDY DESIGN: Pregnant baboons (Papio species) received 2 injections of saline control or 175 µg/kg ßM 24 hours apart at 0.6, 0.65, and 0.7 gestation. Offspring (saline control female, n = 7 and saline control male, n = 6; ßM female [FßM], n = 7 and ßM male [MßM], n = 5) were studied at 2.6-3.2 years with a progressive ratio test for motivation, simple discriminations and reversals for associative learning and rule change plasticity, and an intra/extradimensional set-shifting test for attention allocation. RESULTS: ßM exposure decreased motivation in both sexes. In intra/extradimensional testing, FßM made more errors in the simple discrimination reversal (mean difference of errors [FßM - MßM] = 20.2 ± 9.9; P ≤ .05), compound discrimination (mean difference of errors = 36.3 ± 17.4; P ≤ .05), and compound reversal (mean difference of errors = 58 ± 23.6; P < .05) stages as compared to the MßM offspring. CONCLUSION: This central nervous system developmental programming adds growing concerns of long-term effects of repeated fetal synthetic glucocorticoid exposure. In summary, behavioral effects observed show sex-specific differences in resilience to multiple fetal ßM exposures.

CANTAB delayed matching to sample task performance in juvenile baboons.

This study reports the administration of the Cambridge Neuropsychological Test Automated Battery system's delayed matching to sample (DMTS) task to juvenile baboons. Nine subjects (female=5, male=4) were trained with delay intervals ranging from 0 to 80s. Trial unique stimuli were utilized in combination with matching to sample, in contrast to non-matching to sample, to more accurately assess components of medial temporal lobe (hippocampal formation) mediated working memory. These parameters force subjects to rely on recognition for matching stimuli and overcome their innate tendency to choose novel stimuli (non-matching), thus increasing task difficulty. Testing with delays intervals of 0-2, 4, 8, and 16s revealed decreased percent correct responding as delay intervals increased. An effect of 1 vs. 3 distractor stimuli on accuracy was also noted. Increasing the number of distractors resulted in decreased observing response latencies. The increase in choice response latency seen with increasing delay interval was independent of number of distractor stimuli presented. There were no sex differences in task performance. Our laboratory is focused on understanding the functional consequences of suboptimal conditions during pregnancy and early postnatal life in offspring. The ability of juvenile baboons to perform the DMTS task demonstrates the utility of this non-human primate model in examining pre- and post-natal conditions that impact the development of working memory. Evaluation of causes and consequences of impaired working memory in a variety of human diseases will be assisted by the use of this task in nonhuman primate models of human health and disease.

Influence of gestational overfeeding on cardiac morphometry and hypertrophic protein markers in fetal sheep.

Intrauterine overnutrition is associated with development of cardiovascular disease in adulthood although the underlying mechanism has not been precisely elucidated. This study evaluated the effects of maternal overnutrition on fetal cardiac morphometry and hypertrophy-related mRNA/protein expression. Multiparous ewes were fed either 150% of National Research Council (NRC) nutrient requirements (overfed group) or 100% of NRC requirements (control group) from 60 days before mating to Day 75 (D75) of gestation, when ewes were euthanized. Cardiac morphometry, histology and expression of Akt, forkhead-3a (Foxo3a), glycogen synthase kinase-3ß (GSK3ß), mammalian target of rapamycin (mTOR), NFATc3 and GATA4, atrial natriuretic factor (ANF), calcineurin A and caspase-8 were examined. Crown rump length, left and right ventricular free wall weights and left ventricular wall thickness were increased in D75 overnourished fetuses. Hematoxylin and eosin staining revealed irregular myofiber orientation and increased interstitial space in heart tissues from overfed group. Masson's trichrome staining displayed myofiber hypertrophy and fascicular disarray in heart tissues from overfed group. Overfeeding significantly enhanced Foxo3a phosphorylation in both ventricles, while protein expression of Akt, Foxo3a, GSK3ß and caspase-8 as well as phosphorylated Akt and GSK3ß in either ventricle was unaffected. Overfeeding increased left ventricular mTOR, NFATc3 (both total and phosphorylated) and calcineurin A. GATA4, pGATA4 and ANF expression were unchanged in both ventricles. Collectively, our data suggested that overfeeding during early to mid gestation (D75) leads to morphometric changes without overt pathology which may be related to elevated expression of mTOR, NFATc3, calcineurin A and phosphorylation of Foxo3a, mTOR and NFATc3.

Moderate global reduction in maternal nutrition has differential stage of gestation specific effects on {beta}1- and {beta}2-adrenergic receptors in the fetal baboon liver.

Hepatic ß-adrenergic receptors (ß-ARs) play a pivotal role in mobilization of reserves via gluconeogenesis and glycogenolysis to supply the animal with its energy needs during decreased nutrient availability. Using a unique nutrient-deprived baboon model, we have demonstrated for the first time that immunoreactive hepatic ß(1)- and ß(2)-AR subtypes are regionally distributed and localized on cells around the central lobular vein in 0.5 and 0.9 gestation (G) fetuses of ad libitum fed control (CTR) and maternal nutrient restricted (MNR) mothers. Furthermore, MNR decreased fetal liver immunoreactive ß(1)-AR and increased immunoreactive ß(2)-AR at 0.5G. However, at 0.9G, immunohistochemistry and Western blot analysis revealed a decrease in ß(1)-AR and no change in ß(2)-AR levels. Thus, MNR in a nonhuman primate species has effects on hepatic ß(1)- and ß(2)-ARs that are receptor- and gestation stage-specific and may represent compensatory systems whose effects would increase glucose availability in the presence of nutrient deprivation.