Intrauterine Growth Restriction Offspring Research Articles

Nrf2 deficiency exacerbated pulmonary pyroptosis in maternal hypoxia-induced intrauterine growth restriction offspring mice

Maternal prenatal hypoxia is an important contributor to intrauterine growth restriction (IUGR), which impedes fetal lung maturation and leads to the development of chronic lung diseases. Although evidence suggests the involvement of pyroptosis in IUGR, the molecular mechanism of pyroptosis is still unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been found to potentially interact with gasdermin D (GSDMD), the key protein responsible for pyroptosis, indicating its crucial role in inhibiting pyroptosis. Therefore, we hypothesized that Nrf2 deficiency is a key molecular responsible for lung pyroptosis in maternal hypoxia-induced IUGR offspring mice. Pregnant WT and Nrf2-/- mice were exposed to hypoxia (10.5 % O2) to mimic IUGR model. We assessed body weight, lung histopathology, pulmonary angiogenesis, oxidative stress levels, as well as mRNA and protein expressions related to inflammation in the 2-week-old offspring. Additionally, we conducted a dual-luciferase reporter assay to confirm the targeting relationship between Nrf2 and GSDMD. Our findings revealed that offspring with maternal hypoxia-induced IUGR exhibited reduced birth weight, catch-up growth delay, and pulmonary dysplasia. Furthermore, we observed impaired nuclear translocation of Nrf2 and increased GSDMD-mediated pyroptosis in these offspring with IUGR. Moreover, the dual-luciferase reporter assay demonstrated that Nrf2 could directly inhibit GSDMD transcription; deficiency of Nrf2 exacerbated pyroptosis and pulmonary dysplasia in offspring with maternal hypoxia-induced IUGR. Collectively, our findings suggest that Nrf2 deficiency induces GSDMD-mediated pyroptosis and pulmonary dysplasia in offspring with maternal hypoxia-induced IUGR; thus highlighting the potential therapeutic approach of targeting Nrf2 for treating prenatal hypoxia-induced pulmonary dysplasia in offspring.

Uteroplacental insufficiency decreases leptin expression and impairs lung development in growth-restricted newborn rats.

The study aimed to analyze the effect of uteroplacental insufficiency (UPI) on leptin expression and lung development of intrauterine growth restriction (IUGR) rats. On day 17 of pregnancy, time-dated Sprague-Dawley rats were randomly divided into either an IUGR group or a control group. Uteroplacental insufficiency surgery (IUGR) and sham surgery (control) were conducted. Offspring rats were spontaneously delivered on day 22 of pregnancy. On postnatal days 0 and 7, rats' pups were selected at random from the control and IUGR groups. Blood was withdrawn from the heart to determine leptin levels. The right lung was obtained for leptin and leptin receptor levels, immunohistochemistry, proliferating cell nuclear antigen (PCNA), western blot, and metabolomic analyses. UPI-induced IUGR decreased leptin expression and impaired lung development, causing decreased surface area and volume in offspring. This results in lower body weight, decreased serum leptin levels, lung leptin and leptin receptor levels, alveolar space, PCNA, and increased alveolar wall volume fraction in IUGR offspring rats. The IUGR group found significant relationships between serum leptin, radial alveolar count, von Willebrand Factor, and metabolites. Leptin may contribute to UPI-induced lung development during the postnatal period, suggesting supplementation as a potential treatment. The neonatal rats with intrauterine growth restriction (IUGR) caused by uteroplacental insufficiency (UPI) showed decreased leptin expression and impaired lung development. UPI-induced IUGR significantly decreased surface area and volume in lung offspring. This is a novel study that investigates leptin expression and lung development in neonatal rats with IUGR caused by UPI. If our findings translate to IUGR infants, leptin may contribute to UPI-induced lung development during the postnatal period, suggesting supplementation as a potential treatment.

Microbiota-indole 3-propionic acid-brain axis mediates abnormal synaptic pruning of hippocampal microglia and susceptibility to ASD in IUGR offspring

BackgroundAutism spectrum disorder (ASD) has been associated with intrauterine growth restriction (IUGR), but the underlying mechanisms are unclear.ResultsWe found that the IUGR rat model induced by prenatal caffeine exposure (PCE) showed ASD-like symptoms, accompanied by altered gut microbiota and reduced production of indole 3-propionic acid (IPA), a microbiota-specific metabolite and a ligand of aryl hydrocarbon receptor (AHR). IUGR children also had a reduced serum IPA level consistent with the animal model. We demonstrated that the dysregulated IPA/AHR/NF-κB signaling caused by disturbed gut microbiota mediated the hippocampal microglia hyperactivation and neuronal synapse over-pruning in the PCE-induced IUGR rats. Moreover, postnatal IPA supplementation restored the ASD-like symptoms and the underlying hippocampal lesions in the IUGR rats.ConclusionsThis study suggests that the microbiota-IPA-brain axis regulates ASD susceptibility in PCE-induced IUGR offspring, and supplementation of microbiota-derived IPA might be a promising interventional strategy for ASD with a fetal origin.21xhjpDoyB4JmdH7kH-NGnVideo

Daily injection of the β2 adrenergic agonist clenbuterol improved poor muscle growth and body composition in lambs following heat stress-induced intrauterine growth restriction.

Background: Intrauterine growth restriction (IUGR) is associated with reduced β2 adrenergic sensitivity, which contributes to poor postnatal muscle growth. The objective of this study was to determine if stimulating β2 adrenergic activity postnatal would rescue deficits in muscle growth, body composition, and indicators of metabolic homeostasis in IUGR offspring. Methods: Time-mated ewes were housed at 40°C from day 40 to 95 of gestation to produce IUGR lambs. From birth, IUGR lambs received daily IM injections of 0.8μg/kg clenbuterol HCl (IUGR+CLEN; n = 11) or saline placebo (IUGR; n = 12). Placebo-injected controls (n = 13) were born to pair-fed thermoneutral ewes. Biometrics were assessed weekly and body composition was estimated by ultrasound and bioelectrical impedance analysis (BIA). Lambs were necropsied at 60days of age. Results: Bodyweights were lighter (p ≤ 0.05) for IUGR and IUGR+CLEN lambs than for controls at birth, day 30, and day 60. Average daily gain was less (p ≤ 0.05) for IUGR lambs than controls and was intermediate for IUGR+CLEN lambs. At day 58, BIA-estimated whole-body fat-free mass and ultrasound-estimated loin eye area were less (p ≤ 0.05) for IUGR but not IUGR+CLEN lambs than for controls. At necropsy, loin eye area and flexor digitorum superficialis muscles were smaller (p ≤ 0.05) for IUGR but not IUGR+CLEN lambs than for controls. Longissimus dorsi protein content was less (p ≤ 0.05) and fat-to-protein ratio was greater (p ≤ 0.05) for IUGR but not IUGR+CLEN lambs than for controls. Semitendinosus from IUGR lambs had less (p ≤ 0.05) β2 adrenoreceptor content, fewer (p ≤ 0.05) proliferating myoblasts, tended to have fewer (p = 0.08) differentiated myoblasts, and had smaller (p ≤ 0.05) muscle fibers than controls. Proliferating myoblasts and fiber size were recovered (p ≤ 0.05) in IUGR+CLEN lambs compared to IUGR lambs, but β2 adrenoreceptor content and differentiated myoblasts were not recovered. Semitendinosus lipid droplets were smaller (p ≤ 0.05) in size for IUGR lambs than for controls and were further reduced (p ≤ 0.05) in size for IUGR+CLEN lambs. Conclusion: These findings show that clenbuterol improved IUGR deficits in muscle growth and some metabolic parameters even without recovering the deficit in β2 adrenoreceptor content. We conclude that IUGR muscle remained responsive to β2 adrenergic stimulation postnatal, which may be a strategic target for improving muscle growth and body composition in IUGR-born offspring.

Abstract 028: Sex Differences In Hypertension And Cerebral Oxidative Stress Of Preeclamptic Rat Offspring

Intrauterine growth restriction (IUGR) occurs when the fetus doesn’t receive adequate nutrients. The leading cause of IUGR is placental ischemia, often seen in preeclampsia (PE). Adult IUGR offspring have an increased risk of HTN and oxidative stress (OS), with sex differences. Studies have shown that IUGR males have HTN, cerebrovascular dysfunction (CVD), and cerebral OS at 17 wks; IUGR females are NT with limited CVD and no significant OS. Our study aims to characterize the sex differences in timing and changes of cerebral OS in IUGR offspring. HTN and OS are both present in adult IUGR males, however, the order and timing is unknown. We hypothesize that OS leads to HTN. To test this, we examined the changes in brain OS in 12 wk IUGR and control (CON) males (before HTN), and 17 wk IUGR males (which have HTN) vs CON males. We investigated the same time points in NT females. We divided pups from normal pregnant and PE Sprague-Dawley rats into groups based on pregnancy status and sex. Pups were aged to 12 and 17 wks. We collected brains to measure OS via western blot (Manganese superoxide dismutase) and colorimetric assays: hydrogen peroxide (H 2 O 2 ) and total antioxidant capacity (TAC). 12 wk IUGR and CON offspring were NT with no changes between groups or sex. There were no changes in cerebral H 2 O 2 , TAC, and MnSOD for IUGR offspring compared to their CON. At 17 wks, IUGR males had elevated mean arterial pressure (MAP; 143.0 ± 1.7 vs 133.0 ± 2.7 mmHg; p < 0.01). IUGR females were NT. Cerebral H2O2 levels in IUGR males were elevated (20.5 ± 8.0 vs 3.7 ± 1.0 uM/ mg Protein; p < 0.05) and unchanged in IUGR females. TAC in IUGR males was decreased (157.7 ±21.9 vs 234.9 ± 22.0 mM Trolox/mg Protein; p < 0.05) and unchanged in IUGR females. MnSOD was elevated in females with no differences between groups (150.4 ± 3.8 vs 110.9 ±7.1 IU/Protein/CON%; p < 0.002). All 12 wk rats were NT with no changes in cerebral OS. At 17 wks, IUGR males were HTN with elevated cerebral OS, with no changes in females. The lack of increase in OS at 12 wks, suggest that it’s not a precursor to HTN in males, but rather OS is a downstream effect from HTN. Future studies will look at factors that contribute to HTN and CVD in in IUGR offspring. Studies will also examine why 17 wk female IUGR are protected from HTN and cerebral OS.

Abstract P210: Sex Specific Changes In Cerebral Proinflammatory Cytokines In Intrauterine Growth Restricted Offspring

Background: Intrauterine growth restriction (IUGR) often times results from placental ischemia, which restricts the distribution of nutrients and oxygen to meet the metabolic demand of the growing fetus. IUGR offspring (OS) have an increased risk for developing cerebrovascular diseases (CVD) later in life. Factors for development of CVDs are HTN and inflammation. Our lab has shown 17 week IUGR male rats from preeclamptic pregnancies have HTN and elevated inflammation via systemic IL-17, while our females show no change. The role of inflammation to cause HTN in IUGR offspring in a sex specific manner is unknown and the major focus of this study which examines the changes in cerebral inflammation IUGR offspring at 12 weeks. We hypothesize that cerebral inflammation in IUGR males will be elevated, while no change in female IUGR offspring will be observed. Methods: IUGR offspring originate from preeclamptic Sprague Dawley dams. OS weaned for 3 weeks and were separated by sex and IUGR status. At 12 weeks, the rats underwent carotid catheterization to measure BP. Brains were collected to measure pro-inflammatory cytokines, such as TNF-α and IL-17 via ELISAs. Results: At 12 weeks, all OS were normotensive. Brain TNF-α increased in female IUGR (17,366± 1,500 vs 8,116± 1,341 pg/mL, p<0.05) and was elevated in male IUGR (20,845±7571 vs 8,516±1712 pg/mL, ns). Brain IL-17 increased in male IUGR (13,580± 945 vs 9,620± 945 pg/mL, p<0.05) and was elevated in female IUGR (13,143± 1613 vs 10,930± 696 pg/mL, ns). Systemic IL-17 was increased in IUGR male OS (112±16.8vs100±3.9 IU/Protein/CON %, ns). Conclusion: At 12 weeks, brain TNF-α and IL-17 were elevated in IUGR males and females. The differences in expression of each cytokine between the sexes suggest that IL-17 contributes to the increase in BP, especially in males. Understanding the timing of these developments could help to elucidate the role of inflammation in the development of CVD with or without HTN. This study is clinically relevant as it provides a sex specific inflammatory target for therapeutics, to help prevent hypertension and CVD in IUGR offspring. In the future, we will evaluate the role of inflammation in IUGR offspring in a sex specific manner.

Abstract P202: Changes In Cerebral Mitochondrial Function In Intrauterine Growth-Restricted Offspring Before The Development Of Hypertension And Cerebrovascular Dysfunction

Background: Preeclampsia (PE), new-onset gestational hypertension (HTN) affects 3-8% of all births in the USA. PE is the leading cause for intrauterine growth restriction (IUGR). IUGR children have increased risks of HTN and cerebrovascular disease (CVD) later in life. Prior studies in our lab show adult male IUGR rat offspring (OS) to develop HTN, CVD, and cerebral mitochondrial dysfunction (mtDys) at 17 weeks while female IUGR OS exhibit CVD. The role of mtDys in HTN is unknown and is the focus of our study. We hypothesize that IUGR OS will have mtDys prior to HTN. Methods: Our surgical PE animal model utilized the reduced-uterine-perfusion pressure (RUPP) surgery at GD 14. OS from NP served as controls (CON) while OS from RUPP mothers were IUGR. At 12 weeks, OS BP was measured alongside cerebral mtDys through mitochondrial fusion and fission, electron-transport chain (ETC) proteins, and respiration. Results: BP did not change between sexes or among IUGR and CON offspring. Male IUGR OS showed elevated mtRes (State 2: 199 ± 1.08 v. 76 ± 1.13 pmol/mg, p < .05; State 3: 555 ± 3.02 v. 245 ± 1.77 pmol/mg, p < .05; State 4: 346 ± 1.66 v. 85 ± 1.12 pmol/mg, p < .05). Female IUGR and CON OS had no changes in BP or mtRes. Male IUGR OS had increased mito-fusion proteins MFN-1 (176 ± 1.68 v. 100 ± .57 IU/protein/CON %, p < .05), MFN-2 (155 ± 1.36 v. 100 ± .74 IU/protein/CON %, p < .05) and OPA-1 (166 ± 1.99 v. 100 ± .73 IU/protein/CON %, p < .05). DRP-1 had no changes in males; females had no changes in fusion or fission. Male IUGR OS had changes in ETC proteins (CI: 8 ± 9.34 v. 100 ± .82 IU/protein/CON %, p < .05; CII: 23 ± .53 v. 100 ± .52 IU/protein/CON %, p < .05; CIII: 26 ± .23 v. 100 ± .41 IU/protein/CON %, p < .05), as did female IUGR OS (CI: 12 ± .24 v. 100 ± .86 IU/protein/CON %, p < .05; CII: 29 ± .39 v. 100 ± .61 IU/protein/CON %, p < .05; CIII: 39 ± .56 v. 100 ± .62 IU/protein/CON %, p < .05; CIV: 76 ± .74 v. 100 ± .73 IU/protein/CON %, p < .05) vs. CON OS. Summary: Male IUGR OS have elevated mtRes, changed ETC proteins, and fusion proteins that may lead to mtDys and HTN development. This study is clinically relevant because specific cerebral therapy for mtDys for IUGR OS may prevent HTN and CVD development. Future studies will examine changes in mtDys causing male HTN and protection from HTN in females.

Abstract P420: Changes In Cardiac Oxidative Stress Is Protected In Intrauterine Growth Restricted Females Vs Males Before The Development Of Hypertension And Cardiovascular Diseases

Preeclampsia (PE) is a pregnancy complication characterized by hypertension (HTN) typically during the third trimester. PE is the leading cause for intrauterine growth restricted (IUGR) offspring (OFS). Women with PE and their OFS (IUGR) are at a higher risk for developing cardiovascular diseases (CVD) later in life. Two major factors that contribute to the development of CVDs are HTN and oxidative stress (OS). Studies show that human and animals adult IUGR OFS have a higher risk of developing HTN and CVDs compared to females later in life. The rationale for these sex differences is unknown; and we hypothesize that male IUGR rats will have elevated cardiac oxidative stress, while female IUGR will have lower cardiac OS .To test, we will examine sex differences between 12 week IUGR and control (CON) OFS that are not hypertensive, to determine if there are any change in cardiac OS before the development of HTN and CVD. Methods: Sprague Dawley rats were divided into 4 groups: IUGR male, IUGR female, and control (CON) male and female. IUGR rats were derived from the OFS reduced uterine perfusion pressure (RUPP) PE rat model. CON OFS were from normal pregnant rats. At 12wk, BP was measured via carotid catheterization. Heart tissue was collected to assess oxidative stress, via examining reactive oxygen species (ROS) Heat shock protein 1 (HSP-1) and hydrogen peroxide (H2O2). Antioxidants were measured via manganese superoxide dismutase (MnSOD), copper zinc superoxide dismutase (CuZnSOD) and antioxidant capacity (AC). There were no significant changes in HSP-1, CuZnSOD, and H2O2 between male and female OFS. However, female IUGR OFS had a 20% increase in antioxidant MnSOD (119.9 ± 6.133 vs 93.98 ± 5.197 %MnSOD U/protein/CON, p <0.05) compared to CON in the heart. Male OFS had no significant changes for MnSOD. IUGR female AC had a 2-fold increase in activity (22.13 ± 1.019 vs 14.15 ± 1.852 mM Trolox/mg protein, p <0.05) compared to its CON. Furthermore, IUGR male OFS had a slight decrease in AC compared to CON male (11.00 ± 1.420 vs 13.24 ± 0.4676 mM Trolox/mg protein, ns). The significant increase of AC and MnSOD in IUGR female OFS suggests that females may be more protected from OS, via mitochondria-specific antioxidants compared to males.

Dousing the flame: reviewing the mechanisms of inflammatory programming during stress-induced intrauterine growth restriction and the potential for ω-3 polyunsaturated fatty acid intervention.

Intrauterine growth restriction (IUGR) arises when maternal stressors coincide with peak placental development, leading to placental insufficiency. When the expanding nutrient demands of the growing fetus subsequently exceed the capacity of the stunted placenta, fetal hypoxemia and hypoglycemia result. Poor fetal nutrient status stimulates greater release of inflammatory cytokines and catecholamines, which in turn lead to thrifty growth and metabolic programming that benefits fetal survival but is maladaptive after birth. Specifically, some IUGR fetal tissues develop enriched expression of inflammatory cytokine receptors and other signaling cascade components, which increases inflammatory sensitivity even when circulating inflammatory cytokines are no longer elevated after birth. Recent evidence indicates that greater inflammatory tone contributes to deficits in skeletal muscle growth and metabolism that are characteristic of IUGR offspring. These deficits underlie the metabolic dysfunction that markedly increases risk for metabolic diseases in IUGR-born individuals. The same programming mechanisms yield reduced metabolic efficiency, poor body composition, and inferior carcass quality in IUGR-born livestock. The ω-3 polyunsaturated fatty acids (PUFA) are diet-derived nutraceuticals with anti-inflammatory effects that have been used to improve conditions of chronic systemic inflammation, including intrauterine stress. In this review, we highlight the role of sustained systemic inflammation in the development of IUGR pathologies. We then discuss the potential for ω-3 PUFA supplementation to improve inflammation-mediated growth and metabolic deficits in IUGR offspring, along with potential barriers that must be considered when developing a supplementation strategy.

Sexual Dimorphism in the Closure of the Hippocampal Postnatal Critical Period of Synaptic Plasticity after Intrauterine Growth Restriction: Link to Oligodendrocyte and Glial Dysregulation

Intrauterine growth restriction (IUGR) resulting from hypertensive disease of pregnancy (HDP) leads to sexually dimorphic hippocampal-dependent cognitive and memory impairment in humans. In our translationally relevant mouse model of IUGR incited by HDP, we have previously shown that the synaptic development in the dorsal hippocampus including GABAergic development, NPTX2⁺ excitatory synaptic formation, axonal myelination, and perineural net (PNN) formation were perturbed by IUGR at adolescent equivalence in humans (P40). The persistence of these disturbances through early adulthood and the potential upstream mechanisms are currently unknown. Thus, we hypothesized that NPTX2⁺ expression, PNN formation, axonal myelination, all events closing synaptic development in the hippocampus, will be persistently perturbed, particularly affecting IUGR female mice through P60 given the fact that they had worse short-term recognition memory in this model. We additionally hypothesized that such sexual dimorphism is linked to persistent glial dysregulation. We induced IUGR by a micro-osmotic pump infusion of a potent vasoconstrictor U-46619, a thromboxane A₂-analog, in the last week of the C57BL/6 mouse gestation to precipitate HDP. Sham-operated mice were used as controls. At P60, we assessed hippocampal and hemispheric volumes, NPTX2 expression, PNN formation, as well as myelin basic protein (MBP), Olig2, APC/CC1, and M-NF expression. We also evaluated P60 astrocytic (GFAP) reactivity and microglial (Iba1 and TMEM119) activation using immunofluorescent-immunohistochemistry and Imaris morphological analysis plus cytokine profiling using Meso Scale Discovery platform. IUGR offspring continued to have smaller hippocampal volumes at P60 not related to changes in hemisphere volume. NPTX2⁺ puncta counts and volumes were decreased in IUGR hippocampal CA subregions of female mice compared to sex-matched shams. Intriguingly, NPTX2⁺ counts and volumes were concurrently increased in the dentate gyrus (DG) subregion. PNN volumes were smaller in CA1 and CA3 of IUGR female mice along with PNN intensity in CA3 but they had larger volumes in the CA3 of IUGR male mice. The myelinated axon (MBP⁺) areas, volumes, and lengths were all decreased in the CA1 of IUGR female mice compared to sex-matched shams, which correlated with a decrease in Olig2 nuclear expression. No decrease in the number of APC/CC1⁺ mature oligodendrocytes was identified. We noted an increase in M-NF expression in the mossy fibers connecting DG to CA3 only in IUGR female mice. Reactive astrocytes denoted by GFAP areas, volumes, lengths, and numbers of branching were increased in IUGR female CA1 but not in IUGR male CA3 compared to sex-matched shams. Lastly, activated microglia were only detected in IUGR female CA1 and CA3 subregions. We detected no difference in the cytokine profile between sham and IUGR adult mice of either sex. Collectively, our data support a sexually dimorphic impaired closure of postnatal critical period of synaptic plasticity in the hippocampus of young adult IUGR mice with greater effects on females. A potential mechanism supporting such dimorphism may include oligodendrocyte dysfunction in IUGR females limiting myelination, allowing axonal overgrowth followed by a reactive glial-mediated synaptic pruning.

Effects of intrauterine growth restriction on embryonic hippocampal dentate gyrus neurogenesis and postnatal critical period of synaptic plasticity that govern learning and memory function.

Intrauterine growth restriction (IUGR) complicates up to 10% of human pregnancies and is the second leading cause of perinatal morbidity and mortality after prematurity. The most common etiology of IUGR in developed countries is uteroplacental insufficiency (UPI). For survivors of IUGR pregnancies, long-term studies consistently show a fivefold increased risk for impaired cognition including learning and memory deficits. Among these, only a few human studies have highlighted sex differences with males and females having differing susceptibilities to different impairments. Moreover, it is well established from brain magnetic resonance imaging that IUGR affects both white and gray matter. The hippocampus, composed of the dentate gyrus (DG) and cornu ammonis (CA) subregions, is an important gray matter structure critical to learning and memory, and is particularly vulnerable to the chronic hypoxic-ischemic effects of UPI. Decreased hippocampal volume is a strong predictor for learning and memory deficits. Decreased neuron number and attenuated dendritic and axonal morphologies in both the DG and CA are additionally seen in animal models. What is largely unexplored is the prenatal changes that predispose an IUGR offspring to postnatal learning and memory deficits. This lack of knowledge will continue to hinder the design of future therapy to improve learning and memory. In this review, we will first present the clinical susceptibilities and human epidemiology data regarding the neurological sequelae after IUGR. We will follow with data generated using our laboratory's mouse model of IUGR, that mimics the human IUGR phenotype, to dissect at the cellular and molecular alterations in embryonic hippocampal DG neurogenesis. We will lastly present a newer topic of postnatal neuron development, namely the critical period of synaptic plasticity that is crucial in achieving an excitatory/inhibitory balance in the developing brain. To our knowledge, these findings are the first to describe the prenatal changes that lead to an alteration in postnatal hippocampal excitatory/inhibitory imbalance, a mechanism that is now recognized to be a cause of neurocognitive/neuropsychiatric disorders in at-risk individuals. Studies are ongoing in our laboratory to elucidate additional mechanisms that underlie IUGR-induced learning and memory impairment and to design therapy aimed at ameliorating such impairment.

Dietary Methionine Restriction Alleviates Hyperglycemia in Pigs with Intrauterine Growth Restriction by Enhancing Hepatic Protein Kinase B Signaling and Glycogen Synthesis

BackgroundIndividuals with intrauterine growth restriction (IUGR) are prone to developing type 2 diabetes mellitus (T2DM). Dietary methionine restriction (MR) improves insulin sensitivity and glucose homeostasis in individuals with normal birth weight (NBW). ObjectiveThis study investigated the effects of MR on plasma glucose concentration and hepatic and muscle glucose metabolism in pigs with IUGR. MethodsThirty female NBW and 60 same-sex spontaneous IUGR piglets (Landrace × Yorkshire) were selected. After weaning (day 21), the piglets were fed diets with adequate methionine (NBW-CON and IUGR-CON) or 30% less methionine (IUGR-MR) (n = 6). At day 180, 1 pig with a body weight near the mean of each replication was selected for biochemical analysis. ResultsThe IUGR-CON group showed 41.6%, 68.6%, and 67.1% higher plasma glucose concentration, hepatic phosphoenolpyruvate carboxykinase activity, and glucose-6-phosphatase activity, respectively, than the NBW-CON group (P < 0.05). Muscle glycogen content and glycogen synthase activity were 36.9% and 38.8% lower, respectively, in the IUGR-CON than the NBW-CON group (P < 0.05), respectively, and there was decreased hepatic and muscle protein kinase B phosphorylation in the IUGR-CON group (P < 0.05). Compared with the IUGR-CON pigs, the IUGR-MR pigs had 28.7% lower plasma glucose concentrations (P < 0.05), which were similar to those of the NBW-CON pigs (P ≥ 0.05). The hepatic glycogen content and glycogen synthase activity of the IUGR-MR pigs were 62.9% and 50.8% higher than those of the IUGR-CON pigs (P < 0.05) and 53.5% and 84.3% higher than the NBW-CON pigs (P < 0.05), respectively. The IUGR-MR pigs’ hepatic and muscle protein kinase B phosphorylation was higher than that of the IUGR-CON pigs (P < 0.05) and similar to that of the NBW-CON pigs (P ≥ 0.05). ConclusionsMR attenuates hyperglycemia in IUGR pigs by enhancing hepatic protein kinase B signaling and glycogen synthesis, implying a potential nutritional strategy to prevent type 2 diabetes mellitus in IUGR offspring.

S-43-3: INTRAUTERINE GROWTH RESTRICTION CAUSES AN ALTERATION IN KIDNEY GENE EXPRESSION

High blood pressure (BP) and kidney disease are the leading cause of death in the world population. Experimental and epidemiological studies indicate that the fetal environment is critical in determining adult cardiovascular (CV)-renal outcome. It is known that intrauterine growth restriction (IUGR) or low birth weight (LBW) induces an increased risk of hypertension and kidney disease in later life. Placental insufficiency is the common cause of IUGR. Low birth weight is a significant public health problem globally and is associated with short- and long-term consequences. About 15–20% of all births worldwide are LBW, representing more than 20 million births a year. Clinical studies indicate that birth weight is positively associated with glomerular filtration rate (GFR) and negatively associated with BP. Also, animal models of IUGR exhibit a higher susceptibility to ANGII induced high BP and kidney damage in response to acute ischemic reperfusion injury. Thus, these data suggest that IUGR programs greater risk of hypertension and renal dysfunction. However, the exact mechanisms linking an adverse fetal environment with a later increased risk of these diseases are unclear. Objective: This study aims to evaluate the global genetic change in the kidney of the animal model of IUGR. Design: female C57Bl/6J were mated with male C57bl/6J. Upon confirming the pregnancy by sperm plug (day 0 of gestation), the pregnant animal will be undergone reduced uterine perfusion surgery (RUP) or shame surgery at day 13 of gestation. The offspring of RUP mom will be labeled as IUGR, and from the sham will be labeled as control. The offspring will be used for blood pressure measurement using radio-telemetry and kidney microarray analysis when they reach 24 weeks. Results: Th IUGR offspring significantly has an increase in blood pressure compared to the control. The kidneys of male IUGR have 6529 gene upregulation compared to male control. The make IUGR also has 5713 genes dow-regulation as compared to same-sex control. The female IUGR has 1635 genes upregulated and 1513 genes downregulated compared to the kidney from the female control group. Conclusion: the complication during pregnancy, such as reduced uterine perfusion, which is commonly found in preeclampsia programs, alters gene expression in the kidneys of their offspring. This finding suggests that IUGR causes the gene alteration in the kidneys, which is the primary organ in controlling the blood pressure of the offspring, and may lead to the development of hypertension and kidney disease.

Variation in the Early Life and Adult Intestinal Microbiome of Intra-Uterine Growth Restricted Rat Offspring Exposed to a High Fat and Fructose Diet.

Intra-Uterine Growth Restriction (IUGR) is a risk factor for many adult-onset chronic diseases, such as diabetes and obesity. These diseases are associated with intestinal microbiome perturbations (dysbiosis). The establishment of an intestinal microbiome begins in utero and continues postnatally (PN). Hypercaloric diet-induced dysbiosis is a major driver of childhood obesity. We hypothesized that different postnatal diets superimposed on IUGR will alter the postnatal intestinal microbiome. We compared four experimental rat groups: (1) Ad lib fed regular chow diet pre- and postnatally (CON), (2-3) IUGR induced by maternal caloric restriction prenatally followed postnatally (PN) by either (2) the control diet (IUGR-RC) or (3) High-Fat-high-fructose (IUGR-HFhf) diet, and lastly (4) HFhf ad lib pre- and postnatally (HFhf). Fecal samples were collected from dams and male and female rat offspring at postnatal day 2, 21, and adult day 180 for 16S rRNA gene sequencing. Maternal diet induced IUGR led to dysbiosis of the intestinal microbiome at PN21. Postnatal HFhf diet significantly reduced microbial diversity and worsened dysbiosis reflected by an increased Gammaproteobacteria/Clostridia ratio. Dysbiosis arising from a mismatch between IUGR and a postnatal HFhf diet may contribute to increased risk of the IUGR offspring for subsequent detrimental health problems.

Altered Liver Metabolism, Mitochondrial Function, Oxidative Status, and Inflammatory Response in Intrauterine Growth Restriction Piglets with Different Growth Patterns before Weaning.

Frequent occurrence of intrauterine growth restriction (IUGR) causes huge economic losses in the pig industry. Accelerated catch-up growth (CUG) in the early stage of life could restore multiple adverse outcomes of IUGR offspring; however, there is little knowledge about this beneficial phenomenon. We previously found that nutrient absorption related to intestinal function was globally promoted in CUG-IUGR piglets before weaning, which might be the dominant reason for CUG, but what this alteration could lead to in subsequent liver metabolism is still unknown. Firstly, a Normal, CUG, and non-catch-up growth (NCUG) piglet model before weaning was established by dividing eighty litters of newborn piglets into normal birth weight (NBW) and IUGR groups according to birth weight, and those piglets with IUGR but above-average weanling body weight were considered CUG, and the piglets with IUGR still below average body weight were considered NCUG at weaning day (d 26). Liver samples were collected and then systematically compared in glycolipid metabolism, mitochondrial function, antioxidant status, and inflammatory status among these three different growth models. Enhanced hepatic uptake of fatty acids, diminished de novo synthesis of fatty acids, and increased oxidation of fatty acids were observed in CUG livers compared to Normal and NCUG. In contrast, the NCUG liver showed enhanced glucose uptake and gluconeogenesis compared to Normal and CUG. We also observed deteriorating hepatic vacuolation in NCUG piglets, while increasing hepatic lipid deposition in CUG piglets. Besides, the expression of genes related to mitochondrial energy metabolism and biogenesis was reduced in CUG piglets and the phosphorylation level of AMPK was significantly higher compared to Normal (p < 0.05). Moreover, NCUG liver showed decreased T-AOC (p < 0.01) and GSH-PX (p < 0.05), increased MDA concentrations (p < 0.01), upregulated phosphorylation levels of ERK and NF-κB (p < 0.05), and elevated pro-inflammatory factors IL-1β, IL-6 and TNF-α (p < 0.05) compared to Normal. Furthermore, correlation analysis revealed a significant positive correlation between glucose metabolism and inflammatory factors, while a negative correlation between mitochondrial function-related genes and fatty acid transport. NGUG piglets showed simultaneous enhancement of glucose uptake and gluconeogenesis, as well as reduced antioxidant capacity and increased inflammatory status, whereas CUG comes at the expense of impaired hepatic mitochondrial function and pathological fat accumulation.

Effects of Maternal Protein Supplementation at Mid-Gestation of Cows on Intake, Digestibility, and Feeding Behavior of the Offspring.

Simple SummaryIt is well known that intrauterine growth-restricted offspring present physiologic and metabolic modifications later in life. Therefore, understanding the impact of the maternal nutritional plane on feed intake patterns may lead to new feeding strategies to improve the feed efficiency and performance of beef cattle. In this study, we have evaluated the effect of maternal protein supplementation (PS) during mid-gestation and its interaction with the offspring’s sex on the voluntary feed intake and nutrient use of the progeny. Our results show that PS during mid-gestation increases performance and improves the voluntary feed intake of the offspring. Prenatal PS induced favorable changes in the feeding behavior, in which CON offspring spent more time per day eating supplements and ruminating but spent fewer periods in idleness. Maternal protein restriction demonstrated positive effects on the ability to digest the nutrients of male calves. In summary, our data show that PS alters the gain potential, indirectly demonstrating an increase in their nutritional requirements. In contrast, protein restriction causes a compensatory mechanism on the offspring’s nutrient useability in a sex-dependent manner, increasing the total tract digestibility of nutrients in response to a growth-restriction exposure during intrauterine development.This study aimed to assess the effects of maternal protein supplementation and offspring sex (OS) on the intake parameters of the offspring. Forty-three Tabapuã cows were randomly allocated in the following treatments: protein supplementation (PS) during days 100–200 of gestation (RES, 5.5% total crude protein (CP), n = 2, or CON, 10% total CP, n = 19) and OS (females, n = 20; males, n = 23). The offspring were evaluated during the cow–calf (0–210 days), backgrounding (255–320 days), growing 1 (321–381 days), and growing 2 (382–445 days) phases. The CON offspring tended to present higher dry matter intake (DMI) at weaning (p = 0.06). The CON males presented lower digestibility of major diet components in the growing 2 phase (p ≤ 0.02). The CON offspring spent 52% more time per day eating supplements at 100 days and 17% less time in idleness at 210 days. The CON males spent 15 min more per day ruminating than RES males in the feedlot phase (p = 0.01). We concluded that protein supplementation over gestation alters the offspring feed intake pattern as a whole, while protein restriction promotes compensatory responses on nutrient digestibility in males.

PSIII-A-8 Daily Clenbuterol Administration to Lambs Born with low Birthweight due to Intrauterine Growth Restriction Recovered Growth Rates and Improved Body Composition at 60 D of age

Abstract Low birthweight due to intrauterine growth restriction (IUGR) results from unfavorable in utero conditions (i.e., hypoxemia, hypoglycemia) that impairs growth capacity for muscle and other tissues. This programming effect reduces growth efficiency in IUGR offspring below their genetic potential. Specific programming mechanisms are not known, but recent evidence indicates reduced β2 adrenergic regulation of IUGR muscle. Thus, our objective was to determine if early-life growth deficits in IUGR juvenile lambs are improved by manipulating β2 adrenergic activity with daily IM administration of the β2 agonist, clenbuterol (Clen), from birth to 60 d of age. Maternal heat stress-induced IUGR (n=10) and IUGR+Clen (n=9) lambs were smaller (P&amp;lt; 0.05) than controls (n=11) at birth, weighed 18% and 11% less (P&amp;lt; 0.05), respectively, than controls at 30 d of age, and weighed 16% and 13% less (P&amp;lt; 0.05), respectively, at 60 d of age. Average daily gain at 30 and 60 d of age was reduced (P≤0.05) for IUGR but not IUGR+Clen lambs compared to controls. Bioelectrical impedance analysis was used to estimate body composition in live lambs at 58 d of age. Estimated fat-free lean mass and estimated muscle mass were less (P≤0.05) for IUGR but not IUGR+Clen lambs compared to controls. Estimated protein and fat content as well as protein:fat were likewise reduced (P&amp;lt; 0.05) for IUGR but not IUGR+Clen lambs. At necropsy, whole hindlimbs tended to be lighter (P≤0.09) and flexor digitorum superficialis muscle was lighter (P&amp;lt; 0.05) for IUGR but not IUGR+Clen lambs compared to controls. Loin-eye areas measured in chilled carcasses were 15% smaller (P&amp;lt; 0.05) for IUGR lambs and 19% larger (P&amp;lt; 0.05) for IUGR+Clen lambs compared to controls. From this study, we conclude that poor postnatal growth and body composition observed in IUGR juvenile lambs was improved when clenbuterol was used to target programmed deficits in β2 adrenergic regulation of muscle.

Sex differences in cerebrovascular dysfunction and hypertension in offspring of hypertensive pregnant rats

BACKGROUNDOffspring from preeclamptic women have a greater risk of hypertension and cerebrovascular dysfunction later in life. One of the major contributors of cerebrovascular dysfunction is impaired cerebral blood flow (CBF) autoregulation. In the USA, 1 in 25 pregnancies are preeclamptic. Preeclampsia, as defined as new‐onset hypertension during pregnancy, is an inflammatory condition characterized by elevated interleukin 17 (IL‐17), mitochondrial reactive oxygen species (mtROS), mitochondrial dysfunction (mt‐Dys), and intrauterine growth restriction (IUGR). Preliminary work from our laboratory demonstrates that offspring from preeclamptic rats have sex differences. Males have hypertension and a greater impairment of CBF autoregulation, while females have no change in blood pressure with impaired CBF autoregulation. The exact mechanisms for the sex differences in cerebrovascular dysfunction and hypertension is unknown and is the focus of this study. We hypothesize that changes in cerebral mt‐Dys, cerebral mtROS, and circulating IL‐17 contributes to the sex differences in hypertension and cerebrovascular dysfunction in male and female offspring from preeclamptic rats.METHODSIn this study, we compared male and female offspring from normal pregnant and preeclamptic Sprague Dawley rats. All offspring were divided into controls (CON) and IUGR by sex. Hypertensive male and non‐hypertensive female offspring’s with impaired CBF autoregulation were examined at 17 weeks of age for changes in cerebral mitochondrial electron transport chain (ETC) protein complexes, cerebral manganese superoxide dismutase (MnSOD), and circulating IL‐17.RESULTSFemale CON (151±5% IU/Protein/male CON) and IUGR (149±8 %IU/Protein/male CON) offspring have increased MnSOD compared to CON (100±7 %IU/Protein/male CON) and IUGR (122±4 %IU/Protein/male CON) males (p&lt;0.05). No changes in female ETC protein complexes between IUGR and CON. Male IUGR have a decrease in complex II (71±5 vs. 100±8 %IU/Protein/male CON, p&lt;0.05) and V (57±2 vs. 100±10 %IU/Protein/male CON, p&lt;0.05) ETC proteins, and elevated IL‐17 (944±370 vs. 412±115 pg/mL, ns) compared to CON males.CONCLUSIONMale IUGR offspring have mt‐Dys and elevated IL‐17, which may contribute to hypertension and a greater impairment in CBF autoregulation. Female IUGR offspring may be protected due to an increase in mitochondrial antioxidants. In summary, studying the dimorphic sex differences in the mechanisms of hypertension and cerebrovascular dysfunction in offspring of preeclamptic women, may improve the offspring’s risk of hypertension, cardiovascular disease, stroke, and cognitive dysfunction later in life.

Intrauterine Growth Restriction Disrupts the Postnatal Critical Period of Synaptic Plasticity in the Mouse Dorsal Hippocampus in a Model of Hypertensive Disease of Pregnancy

Introduction: Intrauterine growth restriction (IUGR) from hypertensive disease of pregnancy complicates up to 10% of all pregnancies. Significant hippocampal-dependent cognitive and memory impairments as well as neuropsychiatric disorders have been linked to IUGR. Because disturbance of the hippocampal critical period (CPd) of synaptic plasticity leads to impairments similar to those described in IUGR human offspring, we hypothesized that IUGR would perturb the CPd of synaptic plasticity in the mouse hippocampus in our model. Methods: IUGR was produced by a micro-osmotic pump infusion of the potent vasoconstrictor U-46619, a thromboxane A₂-agonist, at embryonic day 12.5 in C57BL/6J mouse dams to precipitate hypertensive disease of pregnancy and IUGR. Sham-operated mice acted as controls. At P10, P18, and P40, we assessed astrogliosis using GFAP-IHC. In dorsal CA1 and CA3 subfields, we assessed the immunoreactivities (IR) (IF-IHC) to (i) parvalbumin (PV) and glutamate decarboxylase (GAD) 65/67, involved in CPd onset; (ii) PSA-NCAM that antagonizes CPd onset; (iii) NPTX2, necessary for excitatory synapse formation and engagement of CPd; and (iv) MBP and WFA, staining perineural nets (PNNs), marking CPd closure. ImageJ/Fiji and IMARIS were used for image processing and SPSS v24 for statistical analysis. Results: Although PV⁺ interneuron numbers and IR intensity were unchanged, development of GAD65/67⁺ synaptic boutons was accelerated at P18 IUGR mice and inversely correlated with decreased expression of PSA-NCAM in the CA of P18 IUGR mice at P18. NPTX2⁺ puncta and total volume were persistently decreased in the CA3 pyramidal and radiatum layers of IUGR mice from P18 to P40. At P40, axonal myelination (MBP⁺) in CA3 of IUGR mice was decreased and correlated with NPTX2 deficits. Lastly, the volume and integrity of the PNNs in the dorsal CA was disrupted in IUGR mice at P40. Discussion/Conclusion: IUGR disrupts the molecular and structural initiation, consolidation, and closure of the CPd of synaptic plasticity in the mouse hippocampus in our model, which may explain the learning and memory deficits observed in juvenile IUGR mice and the cognitive disorders seen in human IUGR offspring. The mechanistic links warrant further investigation, to identify therapeutic targets to prevent neurodevelopmental deficits in patients affected by IUGR.

Abstract 25: Inhibition Of The Agonistic Ang II Type 1 Receptor Autoantibody In A Rat Model Of Preeclampsia Improves Uteroplacental Perfusion And Fetal Growth In Late Gestation

Placenta ischemia, the initiating factor in preeclampsia (PE), is associated with intrauterine growth restriction (IUGR) and increased blood pressure (BP) in offspring. Yet, the only treatment for PE is delivery of the baby and placenta. The Reduced Uterine Perfusion Pressure (RUPP) rat model induced by placental ischemia at gestational day 14 (G14) mimics many facets of human PE including pregnancy-specific hypertension, an increase in the agonistic ANG II Type 1 receptor autoantibody (AT1-AA), IUGR and increased BP in the offspring. Inhibition of AT1-AA using an epitope-binding inhibitory peptide ('n7AAc') attenuates increased BP at gestational day 19 in the RUPP. Yet, whether use of ‘n7aac’ improves fetal growth and mitigates increased BP in the offspring is unknown. Thus, we tested the hypothesis that maternal administration of ‘n7aac’ improves fetal growth by attenuating reduced uterine blood flow and impaired placental remodeling. Sham or RUPP surgery was performed at G14 with administration of vehicle or ‘n7aac’ (144μg/day) via mini osmotic pump until gestational day 20 (G20). At G20 uterine artery resistance index was significantly elevated in vehicle RUPP (0.69±0.02 mm/s n=10) compared to vehicle Sham (0.48±0.02 mm/s n=8) (P&lt;0.0001) and not increased in treated RUPP (0.49±0.02 mm/s n=10) or treated Sham (0.48±0.02 mm/s n=9). Fetal weight was significantly reduced in vehicle RUPP (3.24±0.2 g) compared to vehicle Sham (3.92±0.05 g) (P=0.013) and not decreased in treated RUPP (3.70±0.04 g) or Sham (3.98±0.10 g). Litter size of viable pups at G20 was only reduced in treated RUPP (5.3±1.4) compared to vehicle Sham (11.56±0.7) (P=0.003). Importantly, using in vivo imaging, little to no auto fluorescence of rhodamine-labeled peptide (480 μg/kg/day, n=4) was detectable in the pups at G20. Thus, our results demonstrate that maternal treatment with ‘n7aac’ in the RUPP rat model of PE improve UARI, which is associated with improved fetal weight at G20 in response to placental ischemia. Whether this benefit continues to birth and mitigates increased BP in IUGR offspring is unknown but is the focus of future studies. In conclusion, inhibition of the AT1AA during PE may not only provide benefit to the mother, but may also be associated with benefit in the offspring.