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Tolcos M, Petratos S, Hirst JJ, Wong F, Spencer SJ, Azhan A, Emery B, Walker DW. Blocked, delayed, or obstructed: What causes poor white matter development in intrauterine growth restricted infants? Prog Neurobiol 2017; 154:62-77. [PMID: 28392287 DOI: 10.1016/j.pneurobio.2017.03.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 03/17/2017] [Accepted: 03/29/2017] [Indexed: 12/22/2022]
Abstract
Poor white matter development in intrauterine growth restricted (IUGR) babies remains a major, untreated problem in neonatology. New therapies, guided by an understanding of the mechanisms that underlie normal and abnormal oligodendrocyte development and myelin formation, are required. Much of our knowledge of the mechanisms that underlie impaired myelination come from studies in adult demyelinating disease, preterm brain injury, or experimental models of hypoxia-ischemia. However, relatively less is known for IUGR which is surprising because IUGR is a leading cause of perinatal mortality and morbidity, second only to premature birth. IUGR is also a significant risk factor for the later development of cerebral palsy, and is a greater risk compared to some of the more traditionally researched antecedents - asphyxia and inflammation. Recent evidence suggests that the white matter injury and reduced myelination in the brains of some preterm babies is due to impaired maturation of oligodendrocytes thereby resulting in the reduced capacity to synthesize myelin. Therefore, it is not surprising that the hypomyelination observable in the central nervous system of IUGR infants has similarly lead to investigations identifying a delay or blockade in the progress of maturation of oligodendrocytes in these infants. This review will discuss current ideas thought to account for the poor myelination often present in the neonate's brain following IUGR, and discuss novel interventions that are promising as treatments that promote oligodendrocyte maturation, and thereby repair the myelination deficits that otherwise persist into infancy and childhood and lead to neurodevelopmental abnormalities.
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Affiliation(s)
- Mary Tolcos
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, 3083, Australia.
| | - Steven Petratos
- Department of Medicine, Central Clinical School, Monash University, Prahran, Victoria, 3004, Australia
| | - Jonathan J Hirst
- School of Biomedical Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Flora Wong
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, 3168, Australia; Monash Newborn and Monash University, Clayton, Victoria, 3168, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, 3083, Australia
| | - Aminath Azhan
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, 3168, Australia
| | - Ben Emery
- Oregon Health and Science University, Portland, OR, 97239-3098, USA
| | - David W Walker
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, 3083, Australia
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Venhoranta H, Bauersachs S, Taponen J, Lohi H, Taira T, Andersson M, Kind A, Schnieke A, Flisikowski K. Fetal growth restriction caused by MIMT1 deletion alters brain transcriptome in cattle. Int J Dev Neurosci 2013; 31:463-7. [PMID: 23726833 DOI: 10.1016/j.ijdevneu.2013.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/25/2013] [Accepted: 05/13/2013] [Indexed: 02/07/2023] Open
Abstract
We examined levels of gene expression in the brains of bovine fetuses carrying a truncated MIMT1 allele, MIMT1(Del), shown to cause late abortion and stillbirth as a result of fetal growth restriction. MIMT1 is a non-protein coding gene that forms part of the imprinted PEG3 (paternally expressed gene 3) domain. Microarray analysis of brain cortex samples from mid-gestation MIMT1(Del/WT) bovine fetuses and wild-type siblings was performed to study the effect of fetal growth restriction on brain gene expression. Statistical analysis revealed 134 genes with increased mRNA levels and 22 with reduced levels in MIMT1(Del/WT) fetuses. Gene set enrichment analysis identified a relatively small number of significant functional clusters representing three major biological processes: response to oxidative stress, angiogenesis, and epithelial cell proliferation. Gene expression microarray analyses identified increased expression of VIPR2, HTRA1, S100A4 and MYH8 in fetuses carrying the deletion and decreased expression of DRD2, ADAM18, miR345, ZNF585A. ADAM18, DRD2 and S100A4 are known to be involved in prenatal brain development. ZNF585A, miR-345, VIPR2, HTRA1, and MYH8 are known to be involved in cell growth and differentiation, but any role in neural developmental has yet to be elucidated.
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Affiliation(s)
- Heli Venhoranta
- Department of Production Animal Medicine, University of Helsinki, Saarentaus, Finland
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Lee SM, Namgung R, Park MS, Eun HS, Kim NH, Park KI, Lee C. Parenteral nutrition associated cholestasis is earlier, more prolonged and severe in small for gestational age compared with appropriate for gestational age very low birth weight infants. Yonsei Med J 2013; 54:839-44. [PMID: 23709416 PMCID: PMC3663238 DOI: 10.3349/ymj.2013.54.4.839] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE We hypothesized that parenteral nutrition associated cholestasis (PNAC) would be more severe in small for gestational age (SGA) compared with appropriate for gestational age (AGA) very low birth weight (VLBW) infants. MATERIALS AND METHODS Sixty-one VLBW infants were diagnosed as PNAC with exposure to parenteral nutrition with elevation of direct bilirubin≥2 mg/dL for ≥14 days. Twenty-one SGA infants and 40 AGA infants matched for gestation were compared. RESULTS Compared with AGA infants, PNAC in SGA infants was diagnosed earlier (25±7 days vs. 35±14 days, p=0.002) and persisted longer (62±36 days vs. 46±27 days, p=0.048). Severe PNAC, defined as persistent elevation of direct bilirubin≥4 mg/dL for more than 1 month with elevation of liver enzymes, was more frequent in SGA than in AGA infants (61% vs. 35%, p=0.018). The serum total bilirubin and direct bilirubin levels during the 13 weeks of life were significantly different in SGA compared with AGA infants. SGA infants had more frequent (76% vs. 50%, p=0.046), and persistent elevation of alanine aminotransferase. CONCLUSION The clinical course of PNAC is more persistent and severe in SGA infants. Careful monitoring and treatment are required for SGA infants.
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Affiliation(s)
- Soon Min Lee
- Division of Neonatology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Ran Namgung
- Division of Neonatology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Min Soo Park
- Division of Neonatology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Ho Sun Eun
- Division of Neonatology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Nam Hyo Kim
- Department of Pediatrics, Sung-Ae General Hospital, Seoul, Korea
| | - Kook In Park
- Division of Neonatology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Chul Lee
- Division of Neonatology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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Bagley HN, Wang Y, Campbell MS, Yu X, Lane RH, Joss-Moore LA. Maternal docosahexaenoic acid increases adiponectin and normalizes IUGR-induced changes in rat adipose deposition. J Obes 2013; 2013:312153. [PMID: 23533720 PMCID: PMC3606778 DOI: 10.1155/2013/312153] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 02/01/2013] [Indexed: 12/17/2022] Open
Abstract
Intrauterine growth restriction (IUGR) predisposes to obesity and adipose dysfunction. We previously demonstrated IUGR-induced increased visceral adipose deposition and dysregulated expression of peroxisome proliferator activated receptor- γ 2 (PPAR γ 2) in male adolescent rats, prior to the onset of obesity. In other studies, activation of PPAR γ increases subcutaneous adiponectin expression and normalizes visceral adipose deposition. We hypothesized that maternal supplementation with docosahexaenoic acid (DHA), a PPAR γ agonist, would normalize IUGR adipose deposition in association with increased PPAR γ , adiponectin, and adiponectin receptor expression in subcutaneous adipose. To test these hypotheses, we used a well-characterized model of uteroplacental-insufficiency-(UPI-) induced IUGR in the rat with maternal DHA supplementation. Our primary findings were that maternal DHA supplementation during rat pregnancy and lactation (1) normalizes IUGR-induced changes in adipose deposition and visceral PPAR γ expression in male rats and (2) increases serum adiponectin, as well as adipose expression of adiponectin and adiponectin receptors in former IUGR rats. Our novel findings suggest that maternal DHA supplementation may normalize adipose dysfunction and promote adiponectin-induced improvements in metabolic function in IUGR.
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Affiliation(s)
- Heidi N. Bagley
- Division of Nutrition, University of Utah, Salt Lake City, UT 84158, USA
| | - Yan Wang
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84158, USA
| | | | - Xing Yu
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84158, USA
| | - Robert H. Lane
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84158, USA
| | - Lisa A. Joss-Moore
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84158, USA
- Division of Neonatology, University of Utah, P.O. Box 581289, Salt Lake City, UT 84158, USA
- *Lisa A. Joss-Moore:
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Story L, Damodaram MS, Allsop JM, McGuinness A, Patel A, Wylezinska M, Hagberg H, Kumar S, Rutherford MA. Brain metabolism in fetal intrauterine growth restriction: a proton magnetic resonance spectroscopy study. Am J Obstet Gynecol 2011; 205:483.e1-8. [PMID: 21861969 DOI: 10.1016/j.ajog.2011.06.032] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/13/2011] [Accepted: 06/07/2011] [Indexed: 11/15/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate alterations in brain metabolism in fetuses with intrauterine growth restriction (IUGR) and evidence of cerebral redistribution of blood flow. STUDY DESIGN Biometry and Doppler assessment of blood flow was assessed with ultrasound in 28 fetuses with IUGR and cerebral redistribution and in 41 appropriately grown control subjects. Proton magnetic resonance spectroscopy of the fetal brain was then performed to determine the presence of choline (Cho), creatine (Cr), N-acetylaspartate (NAA), and lactate and to generate ratios for NAA:Cho, NAA:Cr, and Cho:Cr. RESULTS Sixty-five percent of spectra were interpretable: N-acetylaspartate, choline, and creatine peaks were identified in all these spectra; lactate was present in 5 IUGR fetuses and in 3 appropriately grown fetuses. NAA:Cr and NAA:Cho ratios were significantly lower in IUGR fetuses with cerebral redistribution. CONCLUSION Cerebral redistribution is associated with altered brain metabolism that is evidenced by a reduction in NAA:Cho and NAA:Cr ratios.
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Affiliation(s)
- Lisa Story
- Robert Steiner MRI Unit, Imperial College London, London, England, UK
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Cetin I, Barberis B, Brusati V, Brighina E, Mandia L, Arighi A, Radaelli T, Biondetti P, Bresolin N, Pardi G, Rango M. Lactate detection in the brain of growth-restricted fetuses with magnetic resonance spectroscopy. Am J Obstet Gynecol 2011; 205:350.e1-7. [PMID: 21861968 DOI: 10.1016/j.ajog.2011.06.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 04/29/2011] [Accepted: 06/06/2011] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The objective of the study was to determine the feasibility of detecting fetal brain lactate, a marker of fetal metabolic acidemia, using a noninvasive technique, proton magnetic resonance spectroscopy ((1)H MRS), in intrauterine growth-restricted (IUGR) fetuses. STUDY DESIGN In vivo human fetal brain lactate detection was determined by (1)H MRS in 5 fetuses with IUGR. Oxygenation and acid-base balance data were obtained at birth. RESULTS (1)H MRS analysis showed the presence of a lactate peak in the brain of the most severely affected IUGR fetus, with abnormal umbilical artery Doppler and fetal heart rate tracing. This finding was consistent with the low oxygen content and high lactic acid concentration observed in umbilical blood obtained at delivery. CONCLUSION (1)H MRS allows the noninvasive detection of cerebral lactate in IUGR fetuses. Lactate detected by (1)H MRS may represent a possible marker of in utero cerebral injury or underperfusion.
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Affiliation(s)
- Irene Cetin
- Center for Fetal Research Giorgio Pardi, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
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Joss-Moore LA, Wang Y, Ogata EM, Sainz AJ, Yu X, Callaway CW, McKnight RA, Albertine KH, Lane RH. IUGR differentially alters MeCP2 expression and H3K9Me3 of the PPARγ gene in male and female rat lungs during alveolarization. ACTA ACUST UNITED AC 2011; 91:672-81. [PMID: 21425435 DOI: 10.1002/bdra.20783] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 11/16/2010] [Accepted: 12/09/2010] [Indexed: 01/01/2023]
Abstract
Intrauterine growth restriction (IUGR) increases the risk of postnatal lung disease, with males more affected. In rat lungs, IUGR impairs alveolarization in conjunction with altered expression of peroxisome proliferator-activated receptor gamma (PPARγ). In non-lung cells, PPARγ transcription is regulated in part by the epigenetic modifying enzyme, and the methyl CpG binding protein 2 (MeCP2). However, it is unknown if IUGR affects MeCP2 expression or its interaction with PPARγ in the rat lung during alveolarization. In this study, we hypothesized that the rat lung would be characterized by the presence of MeCP2 short and long mRNA transcripts, MeCP2 protein isoforms, and the MeCP2 regulatory micro RNA, miR132. We further hypothesized that IUGR would, in a gender-specific manner, alter the levels of MeCP2 components in association with changes in PPARγ mRNA, MeCP2 occupancy at the PPARγ promoters, and PPARγ histone 3 lysine 9 trimethylation (H3K9Me3). To test these hypotheses, we used a well-characterized rat model of uteroplacental insufficiency-induced IUGR. We demonstrated the presence of MeCP2 mRNA, protein, and miR132 in the rat lung throughout alveolarization. We also demonstrated that IUGR alters MeCP2 expression and its interaction with PPARγ in a gender-divergent manner. We conclude that IUGR induces gender-specific alterations in the epigenetic milieu in the rat lung. We speculate that in the IUGR rat lung, this altered epigenetic milieu may predispose to gender-specific alterations in alveolarization.
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Affiliation(s)
- Lisa A Joss-Moore
- Division of Neonatology, University of Utah, 295 Chipeta Way 2N141, Salt Lake City, UT 84108, USA.
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Joss-Moore LA, Wang Y, Yu X, Campbell MS, Callaway CW, McKnight RA, Wint A, Dahl MJ, Dull RO, Albertine KH, Lane RH. IUGR decreases elastin mRNA expression in the developing rat lung and alters elastin content and lung compliance in the mature rat lung. Physiol Genomics 2011; 43:499-505. [PMID: 21363967 DOI: 10.1152/physiolgenomics.00183.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Complications of intrauterine growth restriction (IUGR) include increased pulmonary morbidities and impaired alveolar development. Normal alveolar development depends upon elastin expression and processing, as well as the formation and deposition of elastic fibers. This is true of the human and rat. In this study, we hypothesized that uteroplacental insufficiency (UPI)-induced IUGR decreases mRNA levels of elastin and genes required for elastin fiber synthesis and assembly, at birth (prealveolarization) and postnatal day 7 (midalveolarization) in the rat. We further hypothesized that this would be accompanied by reduced elastic fiber deposition and increased static compliance at postnatal day 21 (mature lung). We used a well characterized rat model of IUGR to test these hypotheses. IUGR decreases mRNA transcript levels of genes essential for elastic fiber formation, including elastin, at birth and day 7. In the day 21 lung, IUGR decreases elastic fiber deposition and increases static lung compliance. We conclude that IUGR decreases mRNA transcript levels of elastic fiber synthesis genes, before and during alveolarization leading to a reduced elastic fiber density and increased static lung compliance in the mature lung. We speculate that the mechanism by which IUGR predisposes to pulmonary disease may be via decreased lung elastic fiber deposition.
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Affiliation(s)
- Lisa A Joss-Moore
- Division of Neonatology, University of Utah, Salt Lake City, Utah, USA.
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O'Grady SP, Caprau D, Ke XR, Contreras Y, Haley S, Ermini F, Penn A, Moyer-Mileur L, McKnight R, Lane R. Intrauterine growth restriction alters hippocampal expression and chromatin structure of Cyp19a1 variants. Syst Biol Reprod Med 2010; 56:292-302. [PMID: 20662593 DOI: 10.3109/19396368.2010.490871] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We evaluated the impact of uteroplacental insufficiency (UPI), and subsequent intrauterine growth restriction (IUGR), on serum testosterone and hippocampal expression of Cyp19a1 variants and aromatase in rats. Additionally, we determined UPI induced histone modification of the promoter regions of Cyp19a1 variants using chromatin immunoprecipitation. Cyp19a1 is the gene encoding the protein aromatase, that catalyzes the biosynthesis of estrogens from androgens and is necessary for masculinization of the brain. IUGR was induced via bilateral uterine artery. UPI increased serum testosterone in day of life 0 (D(0)) and day of life 21 (D(21)) IUGR males to 224% and 299% of control values, respectively. While there was no significant impact of UPI on testosterone in D(0) females, testosterone in D(21) IUGR females was 187% of controls. Cyp19a1 variant 1.f and variant II are expressed in the rat hippocampus at D(0) and D(21). UPI significantly reduced expression of Cyp19a1 variant 1.f in D(0) males, with no impact in females. Similarly at D(0), UPI reduced expression of aromatase, the protein encoded by Cyp19a1, in males. Dimethylation of H3K4 was increased in the promoter region of variant 1.f (P1.f) and trimethylation of H3K4 was decreased in the promoter region of variant II (PII). At D(21), dimethylation of H3K4 is significantly reduced in PII of IUGR males. We conclude that UPI increases serum testosterone and reduces Cyp19a1 variant 1.f expression in the hippocampus of D(0) IUGR males. Additionally, UPI alters the chromatin structure of CYP19a1 at both D(0) and D(21).
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IUGR decreases PPARγ and SETD8 Expression in neonatal rat lung and these effects are ameliorated by maternal DHA supplementation. Early Hum Dev 2010; 86:785-91. [PMID: 20869820 PMCID: PMC3138525 DOI: 10.1016/j.earlhumdev.2010.08.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Revised: 08/22/2010] [Accepted: 08/31/2010] [Indexed: 12/28/2022]
Abstract
Intrauterine growth restriction (IUGR) is associated with altered lung development in human and rat. The transcription factor PPARγ, is thought to contribute to lung development. PPARγ is activated by docosahexanoic acid (DHA). One contribution of PPARγ to lung development may be its direct regulation of chromatin modifying enzymes, such as Setd8. In this study, we hypothesized that IUGR would result in a gender-specific reduction in PPARγ, Setd8 and associated H4K20Me levels in the neonatal rat lung. Because DHA activates PPARγ, we also hypothesized that maternal DHA supplementation would normalize PPARγ, Setd8, and H4K20Me levels in the IUGR rat lung. We found that IUGR decreased PPARγ levels, with an associated decrease in Setd8 levels in both male and female rat lungs. Levels of the Setd8-dependent histone modification, H4K20Me, were reduced on the PPARγ gene in both males and females while whole lung H4K20Me was only reduced in male lung. Maternal DHA supplementation ameliorated these effects in offspring. We conclude that IUGR decreases lung PPARγ, Setd8 and PPARγ H4K20Me independent of gender, while decreasing whole lung H4K20Me in males only. These outcomes are offset by maternal DHA. We speculate that maintenance of the epigenetic milieu may be one role of PPARγ in the lung and suggests a novel benefit of maternal DHA supplementation in IUGR.
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Suter M, Bocock P, Showalter L, Hu M, Shope C, McKnight R, Grove K, Lane R, Aagaard-Tillery K. Epigenomics: maternal high-fat diet exposure in utero disrupts peripheral circadian gene expression in nonhuman primates. FASEB J 2010; 25:714-26. [PMID: 21097519 DOI: 10.1096/fj.10-172080] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The effect of in utero exposure to a maternal high-fat diet on the peripheral circadian system of the fetus is unknown. Using mRNA copy number analysis, we report that the components of the peripheral circadian machinery are transcribed in the nonhuman primate fetal liver in an intact phase-antiphase fashion and that Npas2, a paralog of the Clock transcription factor, serves as the rate-limiting transcript by virtue of its relative low abundance (10- to 1000-fold lower). We show that exposure to a maternal high-fat diet in utero significantly alters the expression of fetal hepatic Npas2 (up to 7.1-fold, P<0.001) compared with that in control diet-exposed animals and is reversible in fetal offspring from obese dams reversed to a control diet (1.3-fold, P>0.05). Although the Npas2 promoter remains largely unmethylated, differential Npas2 promoter occupancy of acetylation of fetal histone H3 at lysine 14 (H3K14ac) occurs in response to maternal high-fat diet exposure compared with control diet-exposed animals. Furthermore, we find that disruption of Npas2 is consistent with high-fat diet exposure in juvenile animals, regardless of in utero diet exposure. In summary, the data suggest that peripheral Npas2 expression is uniquely vulnerable to diet exposure.
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Affiliation(s)
- Melissa Suter
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, USA
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12
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Robertson CL, Scafidi S, McKenna MC, Fiskum G. Mitochondrial mechanisms of cell death and neuroprotection in pediatric ischemic and traumatic brain injury. Exp Neurol 2009; 218:371-80. [PMID: 19427308 DOI: 10.1016/j.expneurol.2009.04.030] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2009] [Revised: 04/23/2009] [Accepted: 04/28/2009] [Indexed: 11/30/2022]
Abstract
There are several forms of acute pediatric brain injury, including neonatal asphyxia, pediatric cardiac arrest with global ischemia, and head trauma, that result in devastating, lifelong neurologic impairment. The only clinical intervention that appears neuroprotective is hypothermia initiated soon after the initial injury. Evidence indicates that oxidative stress, mitochondrial dysfunction, and impaired cerebral energy metabolism contribute to the brain cell death that is responsible for much of the poor neurologic outcome from these events. Recent results obtained from both in vitro and animal models of neuronal death in the immature brain point toward several molecular mechanisms that are either induced or promoted by oxidative modification of macromolecules, including consumption of cytosolic and mitochondrial NAD(+) by poly-ADP ribose polymerase, opening of the mitochondrial inner membrane permeability transition pore, and inactivation of key, rate-limiting metabolic enzymes, e.g., the pyruvate dehydrogenase complex. In addition, the relative abundance of pro-apoptotic proteins in immature brains and neurons, and particularly within their mitochondria, predisposes these cells to the intrinsic, mitochondrial pathway of apoptosis, mediated by Bax- or Bak-triggered release of proteins into the cytosol through the mitochondrial outer membrane. Based on these pathways of cell dysfunction and death, several approaches toward neuroprotection are being investigated that show promise toward clinical translation. These strategies include minimizing oxidative stress by avoiding unnecessary hyperoxia, promoting aerobic energy metabolism by repletion of NAD(+) and by providing alternative oxidative fuels, e.g., ketone bodies, directly interfering with apoptotic pathways at the mitochondrial level, and pharmacologic induction of antioxidant and anti-inflammatory gene expression.
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Affiliation(s)
- Courtney L Robertson
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, 21201, USA
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Schober ME, McKnight RA, Yu X, Callaway CW, Ke X, Lane RH. Intrauterine growth restriction due to uteroplacental insufficiency decreased white matter and altered NMDAR subunit composition in juvenile rat hippocampi. Am J Physiol Regul Integr Comp Physiol 2009; 296:R681-92. [DOI: 10.1152/ajpregu.90396.2008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Uteroplacental insufficiency (UPI), the major cause of intrauterine growth restriction (IUGR) in developed nations, predisposes to learning impairment. The underlying mechanism is unknown. Neuronal N-methyl-d-aspartate receptors (NMDARs) are critical for synaptogenesis and learning throughout life. We hypothesized that UPI-induced IUGR alters rat hippocampal NMDAR NR2A/NR2B subunit ratio and/or NR1 mRNA isoform expression and synaptic density at day 21 (P21). To test this hypothesis, IUGR was induced by bilateral uterine artery ligation of the late-gestation Sprague-Dawley dam. At P21, hippocampal NMDAR subunit mRNA and protein were measured, as were levels of synaptophysin. Neuronal, synaptic, and glial density in CA1, CA3, and dentate gyrus (DG) was assessed by immunofluorescence. IUGR increased NR1 mRNA isoform NR1-3a and 1-3b expression in both sexes. In P21 males, IUGR increased protein levels of NR1 C2′ and decreased NR1 C2, NR2A, and the NR2A-to-NR2B ratio, whereas in females, IUGR increased NR2B protein. In males, IUGR was associated with decreased myelin basic protein-to-neuronal nuclei ratio in CA1, CA3, and DG. We conclude that IUGR has sex-specific effects and that neither neuronal loss nor decreased synaptic density appears to account for the changes in NMDAR subunits. Rather, it is possible that synaptic NMDAR subunit composition is altered. Our results suggest that apparent recovery in the IUGR hippocampus may be associated with synaptic hyperexcitability. We speculate that the NMDAR plays an important role in IUGR-associated cognitive impairment.
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Moxon-Lester L, Sinclair K, Burke C, Cowin GJ, Rose SE, Colditz P. Increased cerebral lactate during hypoxia may be neuroprotective in newborn piglets with intrauterine growth restriction. Brain Res 2007; 1179:79-88. [PMID: 17936737 DOI: 10.1016/j.brainres.2007.08.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 08/08/2007] [Accepted: 08/10/2007] [Indexed: 01/07/2023]
Abstract
Intrauterine growth restriction (IUGR) can increase susceptibility to perinatal hypoxic brain injury for reasons that are unknown. Previous studies of the neonatal IUGR brain have suggested that the cerebral mitochondrial capacity is reduced but the glycolytic capacity increased relative to normal weight (NW) neonates. In view of these two factors, we hypothesized that the generation of brain lactate during a mild hypoxic insult would be greater in neonatal IUGR piglets compared to NW piglets. Brain lactate/N-acetylaspartate (NAA) ratios and apparent diffusion coefficients (ADCs) were determined by proton magnetic resonance spectroscopy and imaging of the brain before, during and after hypoxia in seven neonatal piglets with asymmetric IUGR and six NW piglets. During hypoxia, IUGR piglets had significantly higher brain lactate/NAA ratios than NW piglets (P=0.046). The lactate response in the IUGR piglets correlated inversely with apoptosis in the thalamus and frontal cortex of the brain measured 4 h post hypoxia (Pearson's r=0.86, P<0.05). Apoptosis in IUGR piglets with high brain lactate was similar to that in the NW piglets whereas IUGR piglets with low brain lactate had significantly higher apoptosis than NW piglets (P=0.019). ADCs in the high lactate IUGR piglets were significantly lower during hypoxia than in all the other piglets. This signifies increased diffusion of water into brain cells during hypoxia, possibly in response to increased intracellular osmolality caused by high intracellular lactate concentrations. These findings support previous studies showing increased susceptibility to hypoxic brain injury in IUGR neonates but suggest that increased glycolysis during hypoxia confers neuroprotection in some IUGR piglets.
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Affiliation(s)
- Leith Moxon-Lester
- Perinatal Research Centre, University of Queensland, Royal Brisbane and Women's Hospital, Level 6 Ned Hanlon Building, Brisbane, Australia.
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Hershkovitz D, Burbea Z, Skorecki K, Brenner BM. Fetal Programming of Adult Kidney Disease: Cellular and Molecular Mechanisms. Clin J Am Soc Nephrol 2007; 2:334-42. [PMID: 17699433 DOI: 10.2215/cjn.03291006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Dov Hershkovitz
- Laboratory of Molecular Medicine, Rambam Health Care Campus, Technion Israel Institute of Technology, Haifa, Israel
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16
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Fu Q, McKnight RA, Yu X, Callaway CW, Lane RH. Growth retardation alters the epigenetic characteristics of hepatic dual specificity phosphatase 5. FASEB J 2006; 20:2127-9. [PMID: 16940436 DOI: 10.1096/fj.06-6179fje] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Uteroplacental insufficiency leads to intrauterine growth retardation (IUGR) and adult onset insulin resistance in both humans and rats. IUGR rat liver is characterized by persistent changes in histone 3 lysine 9 and lysine 14 acetylation, which may induce postnatal changes in gene expression. We hypothesized that it would be possible to identify hepatic genes whose epigenetic characteristics and mRNA levels are altered due to IUGR using chromatin immunoprecipitation (ChIP) coupled with random primed differential display polymerase chain reaction (PCR). One of the isolated sequences identified contained exon 2 of the dual specificity phosphatase-5 gene (DUSP5). IUGR affected hepatic DUSP5 mRNA levels and exon 2 DNA methylation into adulthood in the rat. DUSP5 dephosphorylates Erk1 and Erk2 within the MAPK signaling cascade, which in turn affects serine 612 phosphorylation of insulin receptor substrate-1 (p612 IRS-1). In adult rat liver, IUGR increased Erk1/Erk2 phosphorylation and p612 IRS-1 phosphorylation. Increased serine phosphorylation of hepatic IRS-1 may contribute to the insulin resistance that characterizes these animals. We conclude that intrauterine growth retardation induced by uteroplacental insufficiency 1) affects the hepatic epigenetic characteristics and mRNA of the DUSP-5 and 2) increases hepatic insulin receptor substrate-1 phosphorylation at serine 612 in adult rats.
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Affiliation(s)
- Qi Fu
- University of Utah School of Medicine, Department of Pediatrics, Division of Neonatology, P.O. Box 581289, Salt Lake City, UT 84158, USA
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17
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Ke X, Lei Q, James SJ, Kelleher SL, Melnyk S, Jernigan S, Yu X, Wang L, Callaway CW, Gill G, Chan GM, Albertine KH, McKnight RA, Lane RH. Uteroplacental insufficiency affects epigenetic determinants of chromatin structure in brains of neonatal and juvenile IUGR rats. Physiol Genomics 2005; 25:16-28. [PMID: 16380407 DOI: 10.1152/physiolgenomics.00093.2005] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Intrauterine growth retardation (IUGR) increases the risk of neuroendocrine reprogramming. In the rat, IUGR leads to persistent changes in cerebral mRNA levels. This suggests lasting alterations in IUGR cerebral transcriptional regulation, which may result from changes in chromatin structure. Candidate nutritional triggers for these changes include altered cerebral zinc and one-carbon metabolite levels. We hypothesized that IUGR affects cerebral chromatin structure in neonatal and postnatal rat brains. Rats were rendered IUGR by bilateral uterine artery ligation; controls (Con) underwent sham surgery. At day of life 0 (d0), we measured cerebral DNA methylation, histone acetylation, expression of chromatin-affecting enzymes, and cerebral levels of one-carbon metabolites and zinc. At day of life 21 (d21), we measured cerebral DNA methylation and histone acetylation, as well as the caloric content of Con and IUGR rat breast milk. At d0, IUGR significantly decreased genome-wide and CpG island methylation, as well as increased histone 3 lysine 9 (H3/K9) and histone 3 lysine 14 (H3/K14) acetylation in the hippocampus and periventricular white matter, respectively. IUGR also decreased expression of the chromatin-affecting enzymes DNA methyltransferase 1 (DNMT1), methyl-CpG binding protein 2 (MeCP2), and histone deacetylase (HDAC)1 in association with increased cerebral levels of zinc. In d21 female IUGR rats, cerebral CpG DNA methylation remained lower, whereas H3/K9 and H3/K14 hyperacetylation persisted in hippocampus and white matter, respectively. In d21 male rats, IUGR decreased acetylation of H3/K9 and H3/K14 in these respective regions compared with controls. Despite these differences, caloric, fat, and protein content were similar in breast milk from Con and IUGR dams. We conclude that IUGR results in postnatal changes in cerebral chromatin structure and that these changes are sex specific.
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Affiliation(s)
- X Ke
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84158, USA
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18
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Fu Q, McKnight RA, Yu X, Wang L, Callaway CW, Lane RH. Uteroplacental insufficiency induces site-specific changes in histone H3 covalent modifications and affects DNA-histone H3 positioning in day 0 IUGR rat liver. Physiol Genomics 2004; 20:108-16. [PMID: 15494474 DOI: 10.1152/physiolgenomics.00175.2004] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Uteroplacental insufficiency and subsequent intrauterine growth retardation (IUGR) increase the risk of adult onset insulin resistance and dyslipidemia in humans and rats. IUGR rats are further characterized by postnatal alterations in hepatic PPAR-γ coactivator (PGC-1) and carnitine-palmitoyl-transferase I (CPTI) expression, as well as overall hyperacetylation of histone H3. However, it is unknown whether the histone H3 hyperacetylation is site specific or relates to the changes in gene expression previously described in IUGR rats. We therefore hypothesized that uteroplacental insufficiency causes site-specific modifications in hepatic H3 acetylation and affects the association of acetylated histone H3 with PGC-1 and CPTI promoter sequences. Uteroplacental insufficiency was used to produce asymmetrical IUGR rats. IUGR significantly increased acetylation of H3 lysine-9 (H3/K9), lysine-14 (H3/K14), and lysine-18 (H3/K18) at day 0 of life, and these changes occurred in association with decreased nuclear protein levels of histone deacetylase 1 (HDAC1) and HDAC activity. Chromatin immunoprecipitation using acetyl-H3/K9 antibody and day 0 chromatin revealed that uteroplacental insufficiency affected the association between acetylated H3/K9 and the promoters of PGC-1 and CPTI, respectively, in IUGR liver. At day 21 of life, the neonatal pattern of H3 hyperacetylation persisted only in the IUGR males. We conclude that uteroplacental insufficiency increases H3 acetylation in a site-specific manner in IUGR liver and that these changes persist in male IUGR animals. The altered association of the PGC-1 and CPTI promoters with acetylated H3/K9 correlates with previous reports of IUGR altering the expression of these genes. We speculate that in utero alterations of chromatin structure contribute to fetal programming.
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Affiliation(s)
- Qi Fu
- University of Utah School of Medicine, Department of Pediatrics, Division of Neonatology, Salt Lake City 84132-2202, USA
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Ke X, McKnight RA, Wang ZM, Yu X, Wang L, Callaway CW, Albertine KH, Lane RH. Nonresponsiveness of cerebral p53-MDM2 functional circuit in newborn rat pups rendered IUGR via uteroplacental insufficiency. Am J Physiol Regul Integr Comp Physiol 2004; 288:R1038-45. [PMID: 15563574 DOI: 10.1152/ajpregu.00701.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Severe uteroplacental insufficiency causes cerebral apoptosis in the fetus. Moderate uteroplacental insufficiency causes intrauterine growth retardation (IUGR) and increases the risk of postnatal neurological morbidity. In the rat, uteroplacental insufficiency and IUGR affect cerebral gene expression of Bcl-2 and predispose the newborn IUGR rat toward cerebral apoptosis when challenged with perinatal hypoxia. Expression of Bcl-2, as well as the proapoptotic protein Bax, is regulated by p53. p53 also induces MDM2 transcription, which functions to limit further p53-induced apoptosis. The predisposition of the IUGR fetus toward cerebral apoptosis suggests that the p53-MDM2 "functional" circuit may be perturbed in the newborn IUGR rat brain. We hypothesized that MDM2 cerebral expression does not increase in response to increased p53 expression or increased levels of phospho-p53 (Ser15), an activated form of p53. To prove this hypothesis, we induced IUGR through bilateral uterine ligation of the pregnant rat. Uteroplacental insufficiency significantly increased p53 mRNA, total p53 protein, and phospho-p53 (Ser15) protein levels in the brain at term. Increased expression of phospho-p53 (Ser15) and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells were localized to the CA1 region of the hippocampus, the subcortical and periventricular white matter, and the amygdala of the IUGR rat brain. In contrast, uteroplacental insufficiency decreased cerebral MDM2 mRNA and phospho-MDM2 (Ser166) protein levels in the IUGR rat pups. We conclude that the cerebral MDM2 response to increased p53 expression is not present in the newborn IUGR rat pup, and we speculate that this contributes to the predisposition of the IUGR fetus toward perinatal and long-term neurodevelopmental morbidities.
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Affiliation(s)
- Xingrao Ke
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, 30 North 1900 East, Rm. 2A100, Salt Lake City, UT 84132-2202, USA
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20
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Stroh M, Zipfel WR, Williams RM, Ma SC, Webb WW, Saltzman WM. Multiphoton microscopy guides neurotrophin modification with poly(ethylene glycol) to enhance interstitial diffusion. NATURE MATERIALS 2004; 3:489-494. [PMID: 15208704 DOI: 10.1038/nmat1159] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Accepted: 05/14/2004] [Indexed: 05/24/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) is a promising therapeutic agent for the treatment of neurodegenerative diseases. However, the limited distribution of this molecule after administration into the brain tissue considerably hampers its efficacy. Here, we show how multiphoton microscopy of fluorescently tagged BDNF in brain-tissue slices provides a useful and rapid screening method for examining the diffusion of large molecules in tissues, and for studying the effects of chemical modifications-for example, conjugating with polyethylene glycol (PEG)-on the diffusion constant. This single variable, obtained by monitoring short-term diffusion in real time, can be effectively used for rational drug design. In this study on fluorescently tagged BDNF and BDNF-PEG, we identify slow diffusion as a major contributing factor to the limited penetration of BDNF, and demonstrate how chemical modification can be used to overcome this barrier.
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Affiliation(s)
- Mark Stroh
- Department of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA
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21
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Lane RH, Dvorak B, MacLennan NK, Dvorakova K, Halpern MD, Pham TD, Philipps AF. IGF alters jejunal glucose transporter expression and serum glucose levels in immature rats. Am J Physiol Regul Integr Comp Physiol 2002; 283:R1450-60. [PMID: 12388463 DOI: 10.1152/ajpregu.00172.2002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Milk-borne insulin-like growth factors (IGFs) enhance nutrient absorption in the immature intestine, which is characterized by low levels of glucose oxidation. We therefore hypothesized that feeding a rat milk substitute (RMS) devoid of growth factors to rat pups would lower serum glucose levels relative to dam-fed control rats and that supplementation of RMS with physiological doses of either IGF-I or IGF-II would normalize serum glucose levels via increased jejunal glucose transporter 2 (GLUT2) and high-affinity Na(+)-glucose cotransporter (SGLT1) expression. We found lower serum glucose concentrations in RMS-fed pups; in contrast, serum glucose levels in the IGF-supplemented pups were similar to those of dam-fed controls. RT-PCR and laser scanning confocal microscopy similarly demonstrated that IGF supplementation increased expression of jejunal glucose transporters. Further experiments demonstrated that IGF supplementation altered mRNA levels of key mitochondrial enzymes without altering jejunal lactase activity. We conclude that IGF-I and IGF-II supplementation increases serum glucose levels in the immature rat pup fed artificial formula and alters gene expression of the jejunal glucose transporters.
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Affiliation(s)
- Robert H Lane
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Mattel Children's Hospital, Los Angeles, California 90095-1752, USA.
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22
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Lane RH, Ramirez RJ, Tsirka AE, Kloesz JL, McLaughlin MK, Gruetzmacher EM, Devaskar SU. Uteroplacental insufficiency lowers the threshold towards hypoxia-induced cerebral apoptosis in growth-retarded fetal rats. Brain Res 2001; 895:186-93. [PMID: 11259777 DOI: 10.1016/s0006-8993(01)02074-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Infants suffering uteroplacental insufficiency and hypoxic ischemic injury often demonstrate cerebral apoptosis. Our objective was to determine the global effects of uteroplacental insufficiency upon cerebral gene expression of the apoptosis related proteins Bcl-2 and Bax and their role in increasing vulnerability to hypoxia-induced cerebral apoptosis. We therefore caused uteroplacental insufficiency and growth retardation by performing bilateral uterine artery ligation upon pregnant rats 2 days prior to term delivery and elicited further perinatal fetal hypoxia by placing maternal rats in 14% FiO(2) 3 h prior to delivery. We quantified cerebral levels of Bcl-2 and Bax mRNA, lipid peroxidation, caspase-3 activity, and cAMP in control and growth retarded term rat pups that experienced either normoxia or hypoxia. Uteroplacental insufficiency alone caused a significant decrease in cerebral Bcl-2 mRNA levels without altering cerebral Bax mRNA levels, malondialdehyde levels, or caspase-3 activity. In contrast, uteroplacental insufficiency and subsequent fetal hypoxia significantly increased cerebral Bax mRNA levels, lipid peroxidation and caspase-3 activity; Bcl-2 mRNA levels continued to be decreased. Hypoxia alone increased cerebral cAMP levels, whereas uteroplacental insufficiency and subsequent hypoxia decreased cerebral cAMP levels. We speculate that the decrease in Bcl-2 gene expression increases the vulnerability towards cerebral apoptosis in fetal rats exposed initially to uteroplacental insufficiency and subsequent hypoxic stress.
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Affiliation(s)
- R H Lane
- Department of Pediatrics, UCLA School of Medicine, Mattel Children's Hospital at UCLA, Mental Retardation Research Center, Division of Neonatology and Developmental Biology, 10833 Le Conte Ave B2-375, Los Angeles, CA 90095-1752, USA.
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