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García-García RM, Arias-Álvarez M, Rodríguez M, Sánchez-Rodríguez A, Formoso-Rafferty N, Lorenzo PL, Rebollar PG. Effects of feed restriction during pregnancy on maternal reproductive outcome, foetal hepatic IGF gene expression and offspring performance in the rabbit. Animal 2021; 15:100382. [PMID: 34653786 DOI: 10.1016/j.animal.2021.100382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 11/30/2022] Open
Abstract
Primiparous female rabbits have high nutritional requirements and, while it is recommended that they are subjected to an extensive reproductive rhythm, this could lead to overweight, affecting reproductive outcomes. We hypothesised that restricting food intake during the less energetic period of gestation could improve reproductive outcome without impairing offspring viability. This study compares two groups of primiparous rabbit does in an extensive reproductive programme, one in which feed was restricted from Day 0 to Day 21 of gestation (R021), and another in which does were fed ad libitum (control) throughout pregnancy. The mother and offspring variables compared were (1) mother reproductive outcomes at the time points pre-implantation (Day 3 postartificial insemination [AI]), preterm (Day 28 post-AI) and birth; and (2) the prenatal offspring characteristic IGF system gene expression in foetal liver, liver fibrosis and foetus sex ratio, and postnatal factor viability and growth at birth, and survival and growth until weaning. Feed restriction did not affect the conception rate, embryo survival, or the number of morulae and blastocysts recovered at Day 3 post-AI. Preterm placenta size and efficiency were similar in the two groups. However, both implantation rate (P < 0.001) and the number of foetuses (P = 0.05) were higher in the R021 mothers than controls, while there was no difference in foetal viability. Foetal size and weight, the weights of most organs, organ weight/BW ratios and sex ratio were unaffected by feed restriction; these variables were only affected by uterine position (P < 0.05). Conversely, in the R021 does, foetal liver IGBP1 and IGF2 gene expression were dysregulated despite no liver fibrosis and a normal liver structure. No effects of restricted feed intake were produced on maternal fertility, prolificacy, or offspring birth weight, but control females weaned more kits. Litter weight and mortality rate during the lactation period were also unaffected. In conclusion, pre-implantation events and foetal development were unaffected by feed restriction. While some genes of the foetal hepatic IGF system were dysregulated during pregnancy, liver morphology appeared normal, and the growth of foetuses and kits until weaning was unmodified. This strategy of feed restriction in extensive reproductive rhythms seems to have no significant adverse effects on dam reproductive outcome or offspring growth and viability until weaning.
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Affiliation(s)
- R M García-García
- Department of Physiology, School of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain.
| | - M Arias-Álvarez
- Department of Animal Production, School of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - M Rodríguez
- Department of Agrarian Production, ETSIAAB, Polytechnic University of Madrid, Madrid, Spain
| | - A Sánchez-Rodríguez
- Department of Physiology, School of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - N Formoso-Rafferty
- Department of Agrarian Production, ETSIAAB, Polytechnic University of Madrid, Madrid, Spain
| | - P L Lorenzo
- Department of Physiology, School of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - P G Rebollar
- Department of Agrarian Production, ETSIAAB, Polytechnic University of Madrid, Madrid, Spain
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Lazniewska J, Darby JRT, Holman SL, Sorvina A, Plush SE, Massi M, Brooks DA, Morrison JL. In utero substrate restriction by placental insufficiency or maternal undernutrition decreases optical redox ratio in foetal perirenal fat. JOURNAL OF BIOPHOTONICS 2021; 14:e202000322. [PMID: 33389813 DOI: 10.1002/jbio.202000322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/04/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Intrauterine growth restriction (IUGR) can result from reduced delivery of substrates, including oxygen and glucose, during pregnancy and may be caused by either placental insufficiency or maternal undernutrition. As a consequence of IUGR, there is altered programming of adipose tissue and this can be associated with metabolic diseases later in life. We have utilised two sheep models of IUGR, placental restriction and late gestation undernutrition, to determine the metabolic effects of growth restriction on foetal perirenal adipose tissue (PAT). Two-photon microscopy was employed to obtain an optical redox ratio, which gives an indication of cell metabolism. PAT of IUGR foetuses exhibited higher metabolic activity, altered lipid droplet morphology, upregulation of cytochrome c oxidase subunit genes and decreased expression of genes involved in growth and differentiation. Our results indicate that there are adaptations in PAT of IUGR foetuses that might be protective and ensure survival in response to an IUGR insult.
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Affiliation(s)
- Joanna Lazniewska
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sally E Plush
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Massimiliano Massi
- Department of Chemistry, Curtin University, Perth, Western Australia, Australia
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Gestation Food Restriction and Refeeding Compensate Maternal Energy Status and Alleviate Metabolic Consequences in Juvenile Offspring in a Rabbit Model. Nutrients 2021; 13:nu13020310. [PMID: 33499108 PMCID: PMC7912334 DOI: 10.3390/nu13020310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/12/2022] Open
Abstract
Nutritional status during gestation can influence mother and offspring metabolism. Undernutrition in pregnancy affects women in both western and developing countries, and it is associated with a high prevalence of chronic diseases in later life. The present work was conducted in the rabbit model, as a longitudinal study, to examine the effect of food restriction during early and mid-gestation, and re-feeding ad libitum until the end of pregnancy on metabolic status and body reserves of mother and, its association with development and metabolism of fetuses and female offspring to the juvenile stage. Little changes in live body weight (LBW), compensatory feed intake, similar body reserves, and metabolism were observed in dams. Placenta biometry and efficiency were slightly affected, but fetal BW and phenotype were not modified. However, hyperinsulinemia, insulin resistance, and hypertriglyceridemia were demonstrated in pre-term fetuses. In the juvenile period, these changes were not evidenced, and a similar pattern of growth and serum metabolic parameters in offspring of food-restricted mothers were found, except in serum aminotransferases levels, which increased. These were associated with higher liver fibrosis. Maternal food restriction in the early and mid-pregnancy followed by re-feeding in our rabbit model established a compensatory energy status in dams and alleviated potential long-term consequences in growth and metabolism in the offspring, even if fetal metabolism was altered.
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Female-specific activation of pregnane X receptor mediates sex difference in fetal hepatotoxicity by prenatal monocrotaline exposure. Toxicol Appl Pharmacol 2020; 406:115137. [PMID: 32682830 DOI: 10.1016/j.taap.2020.115137] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/21/2020] [Accepted: 07/10/2020] [Indexed: 01/06/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are a group of hepatic toxicant widely present in plants. Cytochrome P450 (CYP) 3A plays a key role in metabolic activation of PAs to generate electrophilic metabolites, which is the main cause of hepatotoxicity. We have previously demonstrated the sex difference in developmental toxicity and hepatotoxicity in fetal rats exposed to monocrotaline (MCT), a representative toxic PA. The aim of this study was to explore the underlying mechanism. 20 mg·kg-1·d-1 MCT was intragastrically given to pregnant Wistar rats from gestation day 9 to 20. CYP3As expression and pregnane X receptor (PXR) activation were specifically enhanced in female fetal liver. After MCT treatment, we also observed a significant increase of CYP3As expression in LO2 cells (high PXR level) or hPXR-transfected HepG2 cells (low PXR level). Employing hPXR and CYP3A4 dual-luciferase reporter gene assay, we confirmed the agonism effect of MCT on PXR-dependent transcriptional activity of CYP3A4. Agonism and antagonism of the androgen receptor (AR) either induced or blocked MCT-induced PXR activation, respectively. This study was the first report identifying that MCT served as PXR agonist to induce CYP3A expression. CYP3A induction may increase self-metabolic activation of MCT and subsequently lead to more severe hepatotoxicity in female fetus. While in male, during the intrauterine period, activated AR by testosterone secretion from developing testes represses MCT-induced PXR activation and CYP3A induction, which may partially protect male fetus from MCT-induced hepatotoxicity.
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Sun L, Zhang H, Wang Z, Fan Y, Guo Y, Wang F. Dietary rumen-protected arginine and N-carbamylglutamate supplementation enhances fetal growth in underfed ewes. Reprod Fertil Dev 2019; 30:1116-1127. [PMID: 31039923 DOI: 10.1071/rd17164] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 12/29/2017] [Indexed: 01/18/2023] Open
Abstract
The present study was conducted with an ovine intrauterine growth restriction (IUGR) model to test the hypothesis that dietary rumen-protected l-arginine (RP-Arg) or N-carbamylglutamate (NCG) supplementation in underfed ewes is effective in enhancing fetal growth. Between Days 35 and 110 of pregnancy, 32 multiparous ewes carrying two fetuses were randomly assigned to one of four groups: a control (CG) group (n=8; 100% National Research Council (NRC) requirements for pregnant sheep), a nutrient-restricted (RG) group (n=8; fed 50% NRC requirements, and two treatment (ARG and NCG) groups (n=8 in each group; fed 50% NRC requirements supplemented with 20gday-1 RP-Arg or 5gday-1 NCG. All ewes were killed on Day 110 of pregnancy to determine fetal weight and fetal organ weights, and metabolites and hormones in fetal plasma, amino acid concentrations in the fetal liver and longissimus dorsi muscle, and expression of mRNAs in the somatotropic axis. Maternal and fetal bodyweight and the weight of most fetal organs expressed as a percentage of bodyweight increased in response to ARG and NCG compared with values for fetuses from RG ewes. Fetal plasma concentrations of insulin, insulin-like growth factor 1, total amino acids, lactate, thyroxine, and the thyroxine/tri-iodothyronine ratio were lower in fetuses from RG ewes compared with the other treatment groups, but concentrations of growth hormone, non-esterified fatty acids, and total cholesterol were greater in fetuses from RG ewes. Maternal RP-Arg or NCG supplementation increased concentrations of amino acids in fetal tissues and expression of mRNAs for somatotropic axis proteins in fetuses from RG ewes. These findings suggest that maternal RP-Arg and NCG supplementation of underfed ewes decreases fetal IUGR by improving metabolic homeostasis of fetal endocrinology, increasing the availability of amino acids in the fetal liver and longissimus dorsi muscle and affecting the expression of somatotropic axis genes.
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Affiliation(s)
- Lingwei Sun
- Jiangsu Engineering Technology Research Center of Meat Sheep and Goat Industry, Nanjing Agricultural University, #1, Tongwei Road, Nanjing, Jiangsu Province, 210095, PR China
| | - Hao Zhang
- Jiangsu Engineering Technology Research Center of Meat Sheep and Goat Industry, Nanjing Agricultural University, #1, Tongwei Road, Nanjing, Jiangsu Province, 210095, PR China
| | - Ziyu Wang
- Jiangsu Engineering Technology Research Center of Meat Sheep and Goat Industry, Nanjing Agricultural University, #1, Tongwei Road, Nanjing, Jiangsu Province, 210095, PR China
| | - Yixuan Fan
- Jiangsu Engineering Technology Research Center of Meat Sheep and Goat Industry, Nanjing Agricultural University, #1, Tongwei Road, Nanjing, Jiangsu Province, 210095, PR China
| | - Yixuan Guo
- Jiangsu Engineering Technology Research Center of Meat Sheep and Goat Industry, Nanjing Agricultural University, #1, Tongwei Road, Nanjing, Jiangsu Province, 210095, PR China
| | - Feng Wang
- Jiangsu Engineering Technology Research Center of Meat Sheep and Goat Industry, Nanjing Agricultural University, #1, Tongwei Road, Nanjing, Jiangsu Province, 210095, PR China
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Hetz JA, Menzies BR, Shaw G, Renfree MB. The tammar wallaby: a non-traditional animal model to study growth axis maturation. Reprod Fertil Dev 2019; 31:1276-1288. [PMID: 31030727 DOI: 10.1071/rd18271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 03/26/2019] [Indexed: 11/23/2022] Open
Abstract
Maturation of the growth hormone (GH)/insulin-like growth factor 1 (IGF1) axis is a critical developmental event that becomes functional over the peripartum period in precocial eutherian mammals such as sheep. In mice and marsupials that give birth to altricial young, the GH/IGF1 axis matures well after birth, suggesting that functional maturation is associated with developmental stage, not parturition. Recent foster-forward studies in one marsupial, the tammar wallaby (Macropus eugenii), have corroborated this hypothesis. 'Fostering' tammar young not only markedly accelerates their development and growth rates, but also affects the timing of maturation of the growth axis compared with normal growing young, providing a novel non-traditional animal model for nutritional manipulation. This review discusses how nutrition affects the maturation of the growth axis in marsupials compared with traditional eutherian animal models.
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Affiliation(s)
- Jennifer A Hetz
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia; and Escuela de Agronomía, Pontificia Universidad Católica de Valparaíso, Casilla 4-D, Quillota, Región de Valparaíso, Chile
| | - Brandon R Menzies
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia; and Corresponding author.
| | - Geoffrey Shaw
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
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Liu Y, Ma C, Li H, Li L, Gao F, Ao C. Effects of intrauterine growth restriction during late pregnancy on the cell apoptosis and related gene expression in ovine fetal liver. Theriogenology 2016; 90:204-209. [PMID: 28166970 DOI: 10.1016/j.theriogenology.2016.11.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 11/21/2016] [Accepted: 11/28/2016] [Indexed: 12/25/2022]
Abstract
This study investigated the effect of intrauterine growth restriction (IUGR) during late pregnancy on the cell apoptosis and related gene expression in ovine fetal liver. Eighteen time-mated Mongolian ewes with singleton fetuses were allocated to three groups at d 90 of pregnancy: Restricted Group 1 (RG1, 0.18 MJ ME kg BW-0.75 d-1, n = 6), Restricted Group 2 (RG2, 0.33 MJ ME kg BW-0.75 d-1, n = 6) and a Control Group (CG, ad libitum, 0.67 MJ ME kg BW -0.75 d -1, n = 6). Fetuses were recovered at slaughter on d 140. Fetal liver weight, DNA content and protein/DNA ratio, proliferation index, cytochrome c, activities of Caspase-3, 8, and 9 were examined, along with relative expression of genes related to apoptosis. Fetuses in both restricted groups exhibited decreased BW, hepatic weight, DNA content, and protein/DNA ratio when compared to CG (P < 0.05), as well as reduced proliferation index (P < 0.05). However, the increased numbers of apoptotic cells in fetal liver were observed in both restricted groups (P < 0.05). Fetuses with severe IUGR (RG1) exhibited increased (P < 0.05) activities of Caspase-3, 8, 9, as higher levels of mitochondrial cytochrome c in fetal liver; intermediate changes were found in RG2 fetuses, but the difference were not significant (P > 0.05). Hepatic expression of gene related to apoptosis showed reduced protein 21 (P21), B-cell lymphoma 2 (Bcl-2) and apoptosis antigen 1 ligand (FasL) expression in RG1 and RG2 (P < 0.05). In contrast, the increased hepatic expression of protein 53 (P53), Bcl-2 associated X protein (Bax) and apoptosis antigen 1 (Fas) in both IUGR fetuses were found (P < 0.05). These results indicate that the fetal hepatocyte proliferation were arrested in G1 cell cycle, and the fetal hepatocyte apoptosis was sensitive to the IUGR resulted from maternal undernutrition. The cell apoptosis in IUGR fetal liver were the potential mechanisms for its retarded proliferation and impaired development.
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Affiliation(s)
- Yingchun Liu
- College of Life Science, Inner Mongolia Agricultural University, Hohhot, 010018, China; Inner Mongolia Key Laboratory of Biomanufacturing, Hohhot, China
| | - Chi Ma
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Hui Li
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Lingyao Li
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Feng Gao
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018, China.
| | - Changjin Ao
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
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Liao SF, Boling JA, Matthews JC. Gene expression profiling indicates an increased capacity for proline, serine, and ATP synthesis and mitochondrial mass by the liver of steers grazing high vs. low endophyte-infected tall fescue. J Anim Sci 2016; 93:5659-71. [PMID: 26641175 DOI: 10.2527/jas.2015-9193] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Grazing -infected forages results in a variety of reduced animal performance parameters, collectively known as "fescue toxicosis." The initial, limited evaluations of hepatic mechanisms affected by fescue toxicosis have used transcriptomic expression profiling of experimental phenotypes developed by short-term feeding of concentrated ergot alkaloids or fescue seeds to rodents and steers. To assess the effects of fescue toxicosis in growing cattle using a commercially relevant phenotype, we induced fescue toxicosis in beef steers by summer-long grazing (89 to 105 d) of a single high toxic endophyte-infected tall fescue pasture (HE; 0.746 μg/g ergot alkaloids; 5.7 ha; = 10; BW = 267 ± 14.5 kg) vs. a low toxic endophyte tall fescue-mixed pasture (LE; 0.023 μg/g ergot alkaloids; 5.7 ha; = 9; BW = 266 ± 10.9 kg). High toxic endophyte tall fescue-mixed pasture steers had decreased BW (313 vs. 338 kg) and an increased potential for hepatic gluconeogenesis from AA-derived carbons. To gain a greater perspective into fescue toxicosis-induced hepatic metabolism and identify candidate regulatory mechanisms, the goal of the current research was to examine liver samples for changes in gene (mRNA) expression profiles using a Bovine Affymetrix microarray and selected reverse-transcription PCR and immunoblot analyses. The expression (false discovery rate < 10%; < 0.01) of 147 genes was increased (7 to 268%) and that of 227 was decreased (4 to 87%) in livers of HE vs. LE steers. The top (1) functional gene category was cell-mediated immune response (33 genes; ≤ 0.012), (2) canonical cell signaling pathway was primary immunodeficiency signaling (8 genes; ≤ 0.0003), and (3) canonical metabolic pathways were oxidative phosphorylation (5 genes; ≤ 0.016) and purine metabolism (8 genes; ≤ 0.029). High toxic endophyte tall fescue-mixed pasture steers had increased ( ≤ 0.022) expression of genes critical for increased (1) Pro () and Ser () synthesis, (2) shunting of AA carbons into pyruvate () and ATP synthesis (, , , COX4, , and ), and (3) mitochondrial mass (COX4). Targeted reverse-transcribed PCR or immunoblot assays corroborated ( ≤ 0.035) these latter microarray findings for , , , , and COX4. Moreover, network analysis identified glucocorticoid receptor-mediated signaling as the most probable mechanism to coordinate the above findings. These results greatly extend our knowledge of the consequences of summer-long grazing of endophyte-infected tall fescue to the hepatic metabolism of growing steers.
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Hetz JA, Menzies BR, Shaw G, Stefanidis A, Cowley MA, Renfree MB. Effects of nutritional manipulation on body composition in the developing marsupial, Macropus eugenii. Mol Cell Endocrinol 2016; 428:148-60. [PMID: 27032712 DOI: 10.1016/j.mce.2016.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 01/18/2023]
Abstract
When 60-day-old tammar wallaby pouch young (Macropus eugenii) are fostered to mothers at 120 days of lactation, their growth, developmental rate and maturation of their GH/IGF axes are markedly accelerated. To determine the effect of fostering on energy intake, body composition and fat accretion, we first measured total body fat and lean mass in these young. Next, we mimicked the triglyceride oleic and palmitic acid composition of 120-day milk by supplementing 60 day young with these fatty acids and comparing their growth with that of growth accelerated young. There was no difference in the weight or growth axis maturation of supplemented young but there was significantly more body fat in these and in the growth-accelerated fostered young than in controls. We conclude that the accelerated growth and GH/IGF axis maturation observed previously in fostered young is most likely due to increased milk consumption and earlier access to specific nutrients.
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Affiliation(s)
- Jennifer A Hetz
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia
| | - Brandon R Menzies
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia
| | - Geoffrey Shaw
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia
| | - Aneta Stefanidis
- Department of Physiology, Monash University, Victoria, 3800, Australia
| | - Michael A Cowley
- Department of Physiology, Monash University, Victoria, 3800, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia.
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Ocaranza P, Morales F, Matamala Á, Gaete X, Román R, Lammoglia JJ, Cassorla F. Growth hormone signaling in fibroblasts from newborn boys and prepubertal boys. Growth Horm IGF Res 2016; 27:18-27. [PMID: 26843474 DOI: 10.1016/j.ghir.2016.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/06/2016] [Accepted: 01/16/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND/AIM Responsiveness to GH in target cells is mediated by its receptor, which activates the Janus kinase-2 (JAK2) and STAT5 (signal transducers and activators of transcription 5) leading to the expression of IGF-1 and IGFALS. The aim of this study was to compare the GH signaling pathway in newborns and prepubertal boys. SUBJECTS AND METHODS We determined the GHR protein content and the effect of stimulation with recombinant human GH (rhGH; 200ng/mL) on JAK2 and STAT5 phosphorylation in skin fibroblast cultures obtained from newborns and prepubertal boys. The transcript levels of IGFALS and IGF-I, were also studied and compared after 16h or 24h of stimulation with GH in both study groups. RESULTS Newborn infants showed less GHR protein than the prepubertal boys. After rhGH stimulation, JAK2 and STAT5 phosphorylation was absent in skin fibroblasts from newborns, but was clearly detectable in prepubertal boys. After 16h of treatment with rhGH, IGFALS and IGF-I transcript levels increased in the prepubertal boys when compared to baseline. In newborns, however, we did not observe a response after 16 and 24h of rhGH stimulation. CONCLUSION The significant attenuation of the GH signaling pathway observed in fibroblasts from newborn boys appears to be related to a reduction in GHR content and lack of phosphorylation of JAK2 and STAT5 in response to rhGH. This might impair STAT5 dimer formation, leading to a reduction in the transcript levels of IGFALS and IGF-I during the newborn period.
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Affiliation(s)
- Paula Ocaranza
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile.
| | - Fernanda Morales
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile
| | - Álvaro Matamala
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile
| | - Ximena Gaete
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile
| | - Rossana Román
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile
| | - Juan Javier Lammoglia
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile
| | - Fernando Cassorla
- Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile
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Martinez CS, Piazza VG, Díaz ME, Boparai RK, Arum O, Ramírez MC, González L, Becú-Villalobos D, Bartke A, Turyn D, Miquet JG, Sotelo AI. GH/STAT5 signaling during the growth period in livers of mice overexpressing GH. J Mol Endocrinol 2015; 54:171-84. [PMID: 25691498 PMCID: PMC4811361 DOI: 10.1530/jme-14-0262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
GH/STAT5 signaling is desensitized in the liver in adult transgenic mice overexpressing GH; however, these animals present greater body size. To assess whether the STAT5 pathway is active during the growth period in the liver in these animals, and how signaling modulators participate in this process, growing transgenic mice and normal siblings were evaluated. STAT5 does not respond to an acute GH-stimulus, but displays higher basal phosphorylation in the livers of growing GH-overexpressing mice. GH receptor and the positive modulators glucocorticoid receptor and HNF1 display greater abundance in transgenic animals, supporting the activity of STAT5. The negative modulators cytokine-induced suppressor and PTP1B are increased in GH-overexpressing mice. The suppressors SOCS2 and SOCS3 exhibit higher mRNA levels in transgenic mice but lower protein content, indicating that they are being actively degraded. Therefore, STAT5 signaling is increased in the liver in GH-transgenic mice during the growth period, with a balance between positive and negative effectors resulting in accelerated but controlled growth.
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Affiliation(s)
- Carolina S Martinez
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Verónica G Piazza
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - María E Díaz
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Ravneet K Boparai
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Oge Arum
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - María C Ramírez
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Lorena González
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Damasia Becú-Villalobos
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Andrzej Bartke
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Daniel Turyn
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Johanna G Miquet
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Ana I Sotelo
- Facultad de Farmacia y BioquímicaInstituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, ArgentinaDepartment of Geriatrics (A.B.)School of Medicine, Southern Illinois University, Springfield, Illinois, USAInstituto de Biología y Medicina Experimental (CONICET)Vuelta de Obligado 2490, Buenos Aires, Argentina
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12
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Gao F, Liu Y, Li L, Li M, Zhang C, Ao C, Hou X. Effects of maternal undernutrition during late pregnancy on the development and function of ovine fetal liver. Anim Reprod Sci 2014; 147:99-105. [PMID: 24852270 DOI: 10.1016/j.anireprosci.2014.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 04/25/2014] [Accepted: 04/26/2014] [Indexed: 10/25/2022]
Abstract
This study investigated the effects of maternal undernutrition during late pregnancy on the development and function of ovine fetal liver. Eighteen ewes with singleton fetuses were allocated to three groups at d 90 of pregnancy: Restricted Group 1 (RG1, 0.175MJMEkgBW(-0.75)d(-1), n=6), Restricted Group 2 (RG2, 0.33MJMEkgBW(-0.75)d(-1), n=6) and a Control Group (CG, ad libitum, 0.67MJMEkgBW(-0.75)d(-1), n=6). Fetuses were recovered at slaughter on d 140. Fetuses in the RG1 group exhibited decreased (P<0.05) liver weight, total antioxidant capacity (T-AOC), superoxide dismutase activity (SOD), cholinesterase (CHE), total protein (TP), globulin (GLB), and alanine transaminase (ALT). In addition, intermediate changes were found in the RG2 fetuses, including decreased liver weight, T-AOC and CHE (P<0.05). In contrast, increases in fetal hepatic collagen fibers and reticular fibers, glutathione peroxidase (GSH-Px), malondialdehyde (MDA), nitric oxide (NO), nitric oxide synthase (NOs), monoamine oxidase (MAO), albumin (ALB)/GLB, aspartate transaminase (AST), and AST/ALT were found in the RG1 fetuses (P<0.05). The RG2 fetuses had increased fetal hepatic collagen fibers, NOs and MAO (P<0.05) relative to the control fetuses. These results indicate that impaired fetal hepatic growth, fibrosis, antioxidant imbalance and dysfunction were associated with maternal undernutrition.
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Affiliation(s)
- Feng Gao
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China.
| | - Yingchun Liu
- College of Life Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lingyao Li
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Ming Li
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Chongzhi Zhang
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Changjin Ao
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Xianzhi Hou
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
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Vargas VE, Kaushal KM, Monau TR, Myers DA, Ducsay CA. Extracellular signal-regulated kinases (ERK1/2) signaling pathway plays a role in cortisol secretion in the long-term hypoxic ovine fetal adrenal near term. Am J Physiol Regul Integr Comp Physiol 2013; 304:R636-43. [PMID: 23427082 DOI: 10.1152/ajpregu.00318.2012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study assessed the role of the extracellular signal-regulated kinase (ERK) signaling pathway on the previously observed enhanced cortisol secretion in response to adrenocorticotropic hormone (ACTH) treatment in fetal adrenocortical cells (FACs) from long-term hypoxic (LTH) ovine fetuses. Ewes were maintained at high altitude (3,820 m) from ~40 to 138-141 days gestation when FACs were collected and challenged with either ACTH (10 nM) or 8-bromoadenosine 3',5'-cyclic monophosphate (8-bromo-cAMP, 10 mM) in the presence or absence of the mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MEK)/ERK inhibitor UO126 (10 μM). FACs from age-matched normoxic fetuses served as controls. Media and FACs were collected at selected time intervals after ACTH or 8-bromo-cAMP stimulation for cortisol measurement and Western analysis of ERK1/2 and phospho-ERK1 and -2 (pERK1/2). After ACTH or 8-bromo-cAMP treatment, cortisol production was greater in the LTH group compared with control (P < 0.05). UO126 reduced ACTH and 8-bromo-cAMP-mediated cortisol output in both groups (P < 0.01 vs. ACTH or 8-bromo-cAMP alone). Under basal conditions, ERK1/2 and pERK1/2 were not different between LTH and normoxic fetuses. In response to ACTH or 8-bromo-cAMP treatment, ERK1/2 were not different between groups; however, pERK1/2 were elevated in the LTH FACs compared with normoxic control FACs. ERK1/2 phosphorylation declined following ACTH treatment in the control group, but UO126 had no effect on ERK1/2 compared with untreated levels. Both ACTH and 8-bromo-cAMP treatment resulted in a decline of protein levels. UO126 pretreatment virtually eliminated pERK1/2 expression. We conclude that basal ERK signaling in FACs is necessary for normal cortisol production and sustained pERK in LTH adrenals enhances cortisol production.
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Affiliation(s)
- Vladimir E Vargas
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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14
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Martinez CS, Piazza VG, Ratner LD, Matos MN, González L, Rulli SB, Miquet JG, Sotelo AI. Growth hormone STAT5-mediated signaling and its modulation in mice liver during the growth period. Growth Horm IGF Res 2013; 23:19-28. [PMID: 23245546 DOI: 10.1016/j.ghir.2012.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 11/15/2012] [Accepted: 11/19/2012] [Indexed: 12/31/2022]
Abstract
Postnatal growth exhibits two instances of rapid growth in mice: the first is perinatal and independent of growth hormone (GH), the second is peripuberal and GH-dependent. Signal transducer and activator of transcription 5b (STAT5b) is the main GH-signaling mediator and it is related to IGF1 synthesis and somatic growth. The aim of this work was to assess differential STAT5 sensitivity to GH during the growth period in mouse liver of both sexes. Three representative ages were selected: 1-week-old animals, in the GH-independent phase of growth; 2.5-week-old mice, at the onset of the GH-dependent phase of growth; and 9-week-old young adults. GH-signaling mediators were assessed by immunoblotting, quantitative RT-PCR and immunohistochemistry. GH-induced STAT5 phosphorylation is low at one-week and maximal at 2.5-weeks of age when compared to young adults, accompanied by higher protein content at the onset of growth. Suppressor CIS and phosphatase PTP1B exhibit high levels in one-week animals, which gradually decline, while SOCS2 and SOCS3 display higher levels at adulthood. Nuclear phosphorylated STAT5 is low in one-week animals while in 2.5-week animals it is similar to 9-week control; expression of SOCS3, an early response GH-target gene, mimics this pattern. STAT5 coactivators glucocorticoid receptor (GR) and hepatic nuclear factor 1 (HNF1) abundance is higher in adulthood. Therefore, GH-induced STAT5 signaling presents age-dependent activity in liver, with its maximum coinciding with the onset of GH-dependent phase of growth, accompanied by an age-dependent variation of modulating factors. This work contributes to elucidate the molecular mechanisms implicated in GH responsiveness during growth.
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Affiliation(s)
- Carolina S Martinez
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Junín 956, 1113, Buenos Aires, Argentina
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15
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Jensen EC, Bennet L, Wood C, Vickers M, Breier B, Gunn AJ, Keller-Wood M. Loss of the pregnancy-induced rise in cortisol concentrations in the ewe impairs the fetal insulin-like growth factor axis. Reprod Fertil Dev 2011; 23:665-72. [PMID: 21635815 DOI: 10.1071/rd10317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 12/22/2010] [Indexed: 12/12/2022] Open
Abstract
Maternal cortisol levels increase during pregnancy. Although this change is important for optimal fetal growth, the mechanisms of the changes in growth remain unclear. The hypothesis examined was that alterations in maternal plasma cortisol concentrations are associated with changes in the fetal insulin-like growth factor (IGF) axis. Pregnant ewes in late gestation (115 ± 0.4 days) were studied: six control animals, five ewes given 1 mg kg(-1) day(-1) cortisol (high cortisol) and five adrenalectomised ewes given 0.5-0.6 mg kg(-1) day(-1) cortisol (low cortisol). Blood samples were taken throughout the experiment and at necropsy (130 ± 0.2 days) and fetal liver was frozen for mRNA analysis. Fetal IGF-I and insulin plasma concentrations were lower and insulin-like growth factor-binding protein-1 (IGFBP-1) concentrations were higher in the low cortisol group compared with those in the control group (P < 0.05). Fetal liver IGF-II and IGFBP-3 mRNA were decreased in low cortisol animals compared with controls (P < 0.05). There were no significant changes in these parameters in the high cortisol group, and there were no changes in fetal liver IGF-I, growth hormone receptor, IGF-I receptor, IGF-II receptor, IGFBP-1 or IGFBP-2 mRNA levels between the groups. These data suggest that reduced fetal IGF availability contributes to reduced fetal growth when maternal cortisol secretion is impaired, but not during exposure to moderate increases in cortisol.
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Affiliation(s)
- Ellen C Jensen
- Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1023, New Zealand
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Micke G, Sullivan T, Gatford K, Owens J, Perry V. Nutrient intake in the bovine during early and mid-gestation causes sex-specific changes in progeny plasma IGF-I, liveweight, height and carcass traits. Anim Reprod Sci 2010; 121:208-17. [DOI: 10.1016/j.anireprosci.2010.05.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 05/05/2010] [Accepted: 05/25/2010] [Indexed: 01/17/2023]
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Remacle C, Dumortier O, Bol V, Goosse K, Romanus P, Theys N, Bouckenooghe T, Reusens B. Intrauterine programming of the endocrine pancreas. Diabetes Obes Metab 2007; 9 Suppl 2:196-209. [PMID: 17919194 DOI: 10.1111/j.1463-1326.2007.00790.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Epidemiological studies have revealed strong relationships between poor foetal growth and subsequent development of the metabolic syndrome. Persisting effects of early malnutrition become translated into pathology, thereby determine chronic risk for developing glucose intolerance and diabetes. These epidemiological observations identify the phenomena of foetal programming without explaining the underlying mechanisms that establish the causal link. Animal models have been established and studies have demonstrated that reduction in the availability of nutrients during foetal development programs the endocrine pancreas and insulin-sensitive tissues. Whatever the type of foetal malnutrition, whether there are not enough calories or protein in food or after placental deficiency, malnourished pups are born with a defect in their beta-cell population that will never completely recover, and insulin-sensitive tissues will be definitively altered. Despite the similar endpoint, different cellular and physiological mechanisms are proposed. Hormones operative during foetal life like insulin itself, insulin-like growth factors and glucocorticoids, as well as specific molecules like taurine, or islet vascularization were implicated as possible factors amplifying the defect. The molecular mechanisms responsible for intrauterine programming of the beta cells are still elusive, but two hypotheses recently emerged: the first one implies programming of mitochondria and the second, epigenetic regulation.
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Affiliation(s)
- C Remacle
- Laboratory of Cell Biology, Institute of Life Sciences, Catholic University of Louvain, Louvain-la-Neuve, Belgium.
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Brennan KA, Olson DM, Symonds ME. Maternal nutrient restriction alters renal development and blood pressure regulation of the offspring. Proc Nutr Soc 2007; 65:116-24. [PMID: 16441951 DOI: 10.1079/pns2005484] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Studies have shown that the risk of hypertension in adulthood can be affected by the in utero environment. It is established that hypertension is linked to compromised kidney function and that factors affecting organogenesis can increase the risk of later disease. Prostaglandins (PG) and growth factors are known to play an important role in regulating kidney function and renal organogenesis. The extent, however, to which global energy restriction (where all nutrients are reduced) of the mother can programme later blood pressure control or renal PG and growth factor status is unknown. A study is described that aimed to examine the long-term effects of maternal nutrient restriction (NR) and elucidate their relationship with compromised kidney development. First, it was necessary to establish animal models. A sheep model of 50% NR during specific stages of gestation was used to investigate fetal renal development, whilst a rat model of 50% NR throughout pregnancy was used to investigate postnatal kidney development and adult functioning. Molecular analysis has shown that expression of the growth hormone–insulin-like growth factor (GH–IGF) axis is affected by NR in the fetal sheep kidneys, and that changes are dependent on the timing of NR and whether the fetus is a singleton or a twin. Analysis of the kidneys from the rat model has shown nutritional differences in the expression of PG receptors and the enzymes responsible for PG synthesis and degradation that persist into adulthood. In conclusion, NR does affect the GH–IGF and PG axes, and these changes may be important in the nutritional programming of renal functioning and adult blood pressure control.
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Affiliation(s)
- Kathryn A Brennan
- Perinatal Research Centre, Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Canada.
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El Khattabi I, Remacle C, Reusens B. The regulation of IGFs and IGFBPs by prolactin in primary culture of fetal rat hepatocytes is influenced by maternal malnutrition. Am J Physiol Endocrinol Metab 2006; 291:E835-42. [PMID: 16720626 DOI: 10.1152/ajpendo.00509.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During perinatal development, the regulation of IGF system appears to be growth hormone (GH) independent. By using highly purified primary fetal hepatocytes, we investigated the role of prolactin (PRL) in the regulation of IGF system and hepatocyte proliferation. We also analyzed the consequence of a maternal low-protein (LP) diet on the regulation of IGF, IGF-binding protein (IGFBP), and hepatocyte proliferation by prolactin. Pregnant Wistar rats were fed a control (C) diet (20% protein) or isocaloric (LP; 8%) diet throughout gestation. On day 21.5, fetal hepatocytes were cultured for 4 days and incubated with rat prolactin. In the C hepatocytes, PRL at 100 ng/ml decreased the abundance of IGFBP-1 and IGFBP-2 by 50 (P < 0.05) and 60% (P < 0.01), respectively. It also reduced by 70% the level of IGF-II mRNA (P < 0.01). By contrast, PRL failed to modulate IGFBP-1 and IGFBP-2 production by LP hepatocytes, and this was associated with reduced abundance of the short form of PRL receptor (P < 0.05). PRL had no effect on either the proliferation or the IGF-I production by C and LP hepatocytes, although it reduced the expression of IGF-II. These results suggest that prolactin influences hepatocyte proliferation in vitro by inhibiting IGFBP-1, IGFBP-2, and IGF-II levels, which may coincide with the decline of IGF-II observed in rodents during late gestation in vivo. On the other hand, maternal LP diet induces a resistance of fetal hepatocytes to PRL.
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Affiliation(s)
- Ilham El Khattabi
- Laboratoire de Biologie Cellulaire, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
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Mellor DJ, Diesch TJ, Gunn AJ, Bennet L. The importance of ‘awareness’ for understanding fetal pain. ACTA ACUST UNITED AC 2005; 49:455-71. [PMID: 16269314 DOI: 10.1016/j.brainresrev.2005.01.006] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2004] [Revised: 11/17/2004] [Accepted: 01/12/2005] [Indexed: 11/29/2022]
Abstract
Our understanding of when the fetus can experience pain has been largely shaped by neuroanatomy. However, completion of the cortical nociceptive connections just after mid-gestation is only one part of the story. In addition to critically reviewing evidence for whether the fetus is ever awake or aware, and thus able to truly experience pain, we examine the role of endogenous neuro-inhibitors, such as adenosine and pregnanolone, produced within the feto-placental unit that contribute to fetal sleep states, and thus mediate suppression of fetal awareness. The uncritical view that the nature of presumed fetal pain perception can be assessed by reference to the prematurely born infant is challenged. Rigorously controlled studies of invasive procedures and analgesia in the fetus are required to clarify the impact of fetal nociception on postnatal pain sensitivity and neural development, and the potential benefits or harm of using analgesia in this unique setting.
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Affiliation(s)
- David J Mellor
- Riddet Centre and Institute of Food, Nutrition and Human Health, College of Sciences, Massey University, Palmerston North, New Zealand.
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