Nutrient deprivation suppresses protein synthesis by blocking peptide elongation. Transcriptional upregulation and activation of eukaryotic elongation factor 2 kinase (eEF2K) blocks peptide elongation by phosphorylating eukaryotic elongation factor 2. Previous studies examining placentas from intrauterine growth restricted (IUGR) newborn infants show decreased eEF2K expression and activity despite chronic nutrient deprivation.
View Article and Find Full Text PDFIntrauterine growth restriction (IUGR) is a common human pregnancy complication. IUGR offspring carry significant postnatal risk for early-onset metabolic syndrome, which is associated with persistent reduction in IGF-1 protein expression. We have previously shown that preadolescent IUGR male mice have decreased hepatic IGF-1 mRNA and circulating IGF-1 protein at postnatal day 21, the age when growth hormone (GH) normally upregulates hepatic IGF-1 expression.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
July 2015
Intrauterine growth restriction (IUGR) increases the risk for neurodevelopment delay and neuroendocrine reprogramming in both humans and rats. Neuroendocrine reprogramming involves the glucocorticoid receptor (GR) gene that is epigenetically regulated in the hippocampus. Using a well-characterized rodent model, we have previously shown that IUGR increases GR exon 1.
View Article and Find Full Text PDFBackground: Intrauterine growth restriction (IUGR) offspring with rapid catch-up growth are at increased risk for early obesity especially in males. Persistent insulin-like growth factor-1 (IGF-1) reduction is an important risk factor. Using a mouse model of maternal hypertension-induced IUGR, we examined IGF-1 levels, promoter DNA methylation, and histone H3 covalent modifications at birth (D1).
View Article and Find Full Text PDFBackground: Intrauterine growth restriction (IUGR) increases the risk of adult-onset hypercholesterolemia. High-fat diet (HFD) consumption potentiates IUGR-induced increased cholesterol. Cholesterol is converted to bile acids by Cyp7a1 in preparation for excretion.
View Article and Find Full Text PDFBackground: We showed that intrauterine growth restriction (IUGR) increases distal airspace wall thickness at birth (postnatal age 0; P0) in rat pups (saccular stage of lung development). However, that report did not assess whether the saccular phenotype persisted postnatally or occurred in males or females, nor did the report identify a potential molecular pathway for the saccular phenotype at P0. We hypothesized that IUGR persistently delays alveolar formation and disrupts retinoic acid receptor (RAR) mRNA and protein levels in the lung of rat pups in a postnatal age- and sex-specific manner.
View Article and Find Full Text PDFIn utero environmental adaptation may predispose to lifelong morbidity. Organisms fine-tune gene expression to achieve environmental adaptation by epigenetic alterations of histone markers of gene accessibility. One example of epigenetics is how uteroplacental insufficiency-induced intrauterine growth restriction (IUGR), which predisposes to adult onset insulin resistance, decreases postnatal IGF-1 mRNA variants and the gene elongation mark histone 3 trimethylation of lysine 36 of the IGF-1 gene (H3Me3K36).
View Article and Find Full Text PDFIntrauterine growth retardation (IUGR) predisposes humans toward hippocampal morbidities, such as impaired learning and memory. Hippocampal dual specificity phosphatase 5 (DUSP5) may be involved in these morbidities because DUSP5 regulates extracellular signal-regulated kinase phosphorylation (Erk). In the rat, IUGR causes postnatal changes in hippocampal gene expression and epigenetic characteristics.
View Article and Find Full Text PDFBirth Defects Res A Clin Mol Teratol
August 2011
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).
View Article and Find Full Text PDFComplications 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.
View Article and Find Full Text PDFIntrauterine 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).
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
November 2010
Maternal food restriction (FR) during pregnancy results in intrauterine growth-restricted (IUGR) offspring that show rapid catch-up growth and develop metabolic syndrome and adult obesity. However, continued nutrient restriction during nursing delays catch-up growth and prevents development of obesity. Epigenetic regulation of IGF1, which modulates growth and is synthesized and secreted by the liver, may play a role in the development of these morbidities.
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July 2010
Intrauterine growth restriction (IUGR) increases the risk of serious adult morbidities such as hypertension. In an IUGR rat model of hypertension, we reported a persistent decrease in kidney 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) mRNA and protein levels from birth through postnatal (P) day 21. This enzyme deficiency can lead to hypertension by limiting renal glucocorticoid deactivation.
View Article and Find Full Text PDFStudies in humans and rats suggest that intrauterine growth retardation (IUGR) permanently resets the hypothalamic-pituitary-adrenal (HPA) axis. HPA axis reprogramming may involve persistently altered expression of the hippocampal glucocorticoid receptor (hpGR), an important regulator of HPA axis reactivity. Persistent alteration of gene expression, long after the inciting event, is thought to be mediated by epigenetic mechanisms that affect mRNA and mRNA variant expression.
View Article and Find Full Text PDFUteroplacental insufficiency (UPI) induced intrauterine growth restriction (IUGR) predisposes individuals to adult onset metabolic morbidities, including insulin resistance and cardiovascular disease. An underlying component of the development of these morbidities is adipose dysfunction; specifically a disproportionately abundant visceral adipose tissue. We hypothesize that IUGR will increase rats visceral adiposity and visceral expression of PPARgamma, a key regulator of adipogenesis.
View Article and Find Full Text PDFIntrauterine growth restriction (IUGR) decreases serum insulin growth factor-1 (IGF-1) levels. IGF-1 is an epigenetically regulated gene that has two promoters, alternative exon 5 splicing, and multiple termination sites. The regulation of gene expression involves the whole gene, as evidenced by the aforementioned IGF-1 paradigm.
View Article and Find Full Text PDFLow nephron endowment secondary to intrauterine growth restriction (IUGR) results in compensatory hypertrophy of the remaining glomeruli, which in turn is associated with hypertension. However, gender differences exist in the response of the kidney to injury, and IUGR female offspring seems protected from an unfavorable outcome. We previously reported differences in gender-specific gene expression in the IUGR kidney as well as increased circulating corticosterone levels following uteroplacental insufficiency (UPI).
View Article and Find Full Text PDFUteroplacental 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.
View Article and Find Full Text PDFClinical and animal studies indicate that intrauterine growth restriction (IUGR) following uteroplacental insufficiency (UPI) reduces nephron number and predisposes toward renal insufficiency early in life and increased risk of adult-onset hypertension. In this study, we hypothesized that the inducible enzyme cyclooxygenase-2 (COX-2), a pivotal protein in nephrogenesis, constitutes a mechanism through which UPI and subsequent glucocorticoid overexposure can decrease nephron number. We further hypothesized that UPI downregulates the key enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), which converts corticosterone to inert 11-dehydrocorticosterone, thereby protecting both the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR) from the actions of corticosterone.
View Article and Find Full Text PDFUteroplacental 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).
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
August 2006
Uteroplacental insufficiency (UPI) leads to intrauterine growth restriction (IUGR), which predisposes infants toward renal insufficiency early in life and increases the risk of kidney-related adult morbidities, such as hypertension. This compromised in utero environment has been demonstrated to impair nephrogenesis, as evidenced by a reduced nephron endowment in humans and in rats rendered IUGR by UPI. Concordantly, we have observed that IUGR rats have increased kidney p53 protein levels associated with increased apoptosis.
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November 2005
Uteroplacental insufficiency (UPI) induces persistent changes in hepatic gene expression secondary to altered chromatin dynamics in the intrauterine growth- restricted (IUGR) rat liver. The glucocorticoid receptor (GR) is a transcription factor that when activated can induce changes in chromatin structure. To begin the process of identifying pathways by which IUGR affects chromatin structure, we hypothesized that UPI in the rat induces a significant increase in endogenous glucocorticoids (corticosterone) and increases GR expression and activation.
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April 2005
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.
View Article and Find Full Text PDFUteroplacental 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-gamma 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.
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