ABSTRACT: Intermittent neonatal hypoxia elicits the upregulation of inflammatory-related genes in the adult rat through long-lasting programming effects
Project description:The long-term effects of neonatal intermittent hypoxia (IH), an accepted model of apnea-induced hypoxia, are unclear. We have previously shown lasting “programming” effects on the HPA axis in adult rats exposed to neonatal IH. We hypothesized that neonatal rat exposure to IH will subsequently result in a heightened inflammatory state in the adult. Rat pups were exposed to normoxia (control) or six cycles of 5% IH or 10% IH over one hour daily from postnatal day 2 – 6. Plasma samples from blood obtained at 114 days of age were analyzed by assessing the capacity to induce transcription in a healthy peripheral blood mononuclear cell (PBMC) population and read using a high-density microarray. The analysis of plasma from adult rats previously exposed to neonatal 5% IH vs. 10% IH resulted in 2,579 significantly regulated genes including increased expression of Cxcl1, Cxcl2, Ccl3, Il1a, and Il1b. We conclude that neonatal exposure to intermittent hypoxia elicits a long-lasting programming effect in the adult resulting in an upregulation of inflammatory-related genes. Apnea is the most common cause of neonatal hypoxia affecting about 50% of preterm births (30 – 31 weeks), usually due to immature respiratory development. Upregulation of inflammatory genes and pathways in children 7 – 10 years of age has been shown, and there is a known increased risk of insulin resistance in adulthood when the fetus is exposed to maternal hypoxia, but the mechanism is unclear. The long-term metabolic, endocrine, and immunological effects of neonatal intermittent hypoxia (IH) exposure, an accepted model of apnea-induced hypoxia, have not been thoroughly evaluated. Recent studies in rats have shown that perinatal IH exposure can result in oxidative stress, causing a permanent immune response subsequently resulting in features of diabetes mellitus. We have previously examined adult rats exposed to neonatal intermittent hypoxia and perinatal continuous hypoxia, and have found lasting “programming” effects on the HPA axis. We now assess the long term effects of an accepted model of apnea-induced hypoxia using a validated transcriptional bioassay to study the extracellular milieu of adult rats exposed to neonatal intermittent hypoxia. We hypothesize that exposure to neonatal intermittent hypoxia will result in an increased inflammatory state in the adult as a result of long-lasting programming.
Project description:The long-term effects of neonatal intermittent hypoxia (IH), an accepted model of apnea-induced hypoxia, are unclear. We have previously shown lasting âprogrammingâ effects on the HPA axis in adult rats exposed to neonatal IH. We hypothesized that neonatal rat exposure to IH will subsequently result in a heightened inflammatory state in the adult. Rat pups were exposed to normoxia (control) or six cycles of 5% IH or 10% IH over one hour daily from postnatal day 2 â 6. Plasma samples from blood obtained at 114 days of age were analyzed by assessing the capacity to induce transcription in a healthy peripheral blood mononuclear cell (PBMC) population and read using a high-density microarray. The analysis of plasma from adult rats previously exposed to neonatal 5% IH vs. 10% IH resulted in 2,579 significantly regulated genes including increased expression of Cxcl1, Cxcl2, Ccl3, Il1a, and Il1b. We conclude that neonatal exposure to intermittent hypoxia elicits a long-lasting programming effect in the adult resulting in an upregulation of inflammatory-related genes. Apnea is the most common cause of neonatal hypoxia affecting about 50% of preterm births (30 â 31 weeks), usually due to immature respiratory development. Upregulation of inflammatory genes and pathways in children 7 â 10 years of age has been shown, and there is a known increased risk of insulin resistance in adulthood when the fetus is exposed to maternal hypoxia, but the mechanism is unclear. The long-term metabolic, endocrine, and immunological effects of neonatal intermittent hypoxia (IH) exposure, an accepted model of apnea-induced hypoxia, have not been thoroughly evaluated. Recent studies in rats have shown that perinatal IH exposure can result in oxidative stress, causing a permanent immune response subsequently resulting in features of diabetes mellitus. We have previously examined adult rats exposed to neonatal intermittent hypoxia and perinatal continuous hypoxia, and have found lasting âÂÂprogrammingâ effects on the HPA axis. We now assess the long term effects of an accepted model of apnea-induced hypoxia using a validated transcriptional bioassay to study the extracellular milieu of adult rats exposed to neonatal intermittent hypoxia. We hypothesize that exposure to neonatal intermittent hypoxia will result in an increased inflammatory state in the adult as a result of long-lasting programming. Sprague-Dawley (SD) rat pups were treated with neonatal normoxia (21% O2, control), 5% intermittent hypoxia (IH), or 10% IH on postnatal days (PD) 2-6, daily over 1 hr. They were reared normally by birth dams and weaned at PD22. Males were allowed to mature and sacrificed at age PD114 after an overnight fast. Whole blood collected by decapitation into tubes with EDTA, and plasma saved for further analysis. Two adult (~180 day) male Brown Norway (BN) rats served as PBMC donors. Cells were incubated with 20% plasma that was either autologous BN (self-control), or one of 3 pools: a) SD normoxic N=8, b) SD 5% IH treated N=5, and c) SD 10% IH N=3.
Project description:Antenatal hypoxia has critial impacts on fetal heart development. The molecular mechanism of the antenaltal hypoxia effect on the heart development is still unknown. We performed DNA methylome and transcriptome analyses of antenatal hypoxia induced rat fetal and adult offspring hearts to understand the hypoxia-mediated epigenomic programming in the heart development. Heart tissue from fetal (E21) and adult rat (5 months old) were collected. mRNA and genomic DNA methylation profiles of the heart tissue were generated by RNAseq and reduced representation bisulfite seuqencing (RRBS) techniques. We found 323 and 112 differential expressed genes between control and hypoxia groups in the fetal and adult hearts, respectively. Meanwhile, 2828 and 2193 differential methylated regions were identified in the fetal and adult hearts. Furthermore, opposite gobal DNA methylation pattern changes in transcription start site regions (TSS ± 1kb) were observed between fetal and adult hearts. Combining transcriptome, data indicates a significant difference in the responding genes and pathways between fetal and adult hearts in responding to the antenatal hypoxia. Our study provides an initial framework and new insights into fetal hypoxia-mediated epigenetic programming of pro-inflammatory phenotype in the heart development, linking antenatal stress, and developmental programming of heart vulnerability to disease later in life.
Project description:Antenatal hypoxia has critial impacts on fetal heart development. The molecular mechanism of the antenaltal hypoxia effect on the heart development is still unknown. We performed DNA methylome and transcriptome analyses of antenatal hypoxia induced rat fetal and adult offspring hearts to understand the hypoxia-mediated epigenomic programming in the heart development. Heart tissue from fetal (E21) and adult rat (5 months old) were collected. mRNA and genomic DNA methylation profiles of the heart tissue were generated by RNAseq and reduced representation bisulfite seuqencing (RRBS) techniques. We found 323 and 112 differential expressed genes between control and hypoxia groups in the fetal and adult hearts, respectively. Meanwhile, 2828 and 2193 differential methylated regions were identified in the fetal and adult hearts. Furthermore, opposite gobal DNA methylation pattern changes in transcription start site regions (TSS ± 1kb) were observed between fetal and adult hearts. Combining transcriptome, data indicates a significant difference in the responding genes and pathways between fetal and adult hearts in responding to the antenatal hypoxia. Our study provides an initial framework and new insights into fetal hypoxia-mediated epigenetic programming of pro-inflammatory phenotype in the heart development, linking antenatal stress, and developmental programming of heart vulnerability to disease later in life.
Project description:This study examines the relationship between sleep apnea and glucose metabolism. Physiological studies have demonstrated that 5 days of exposure to intermittent hypoxia (similar to what occurs with sleep apnea) leads to significant improvements in glucose tolerance. Therefore, this study investigates the hypothesis that intermittent hypoxia may lead to upregulation of some novel peptide(s) that have a powerful glucose lowering action.
Project description:We hypothesize that the culture media collected from macrophages exposed to intermittent hypoxia will induce a greater pro-inflammatory gene profile in naïve cultured macrophages than will culture media collected from macrophages exposed to sustained hypoxia. We will evaluate gene expression using microarray analysis of RNA collected from RAW 264.7 macrophages cultured for 24 hours in DMEM media obtained from 1) cells cultured with intermittent hypoxia (2 minute cycles: 90 seconds at 40 Torr and 30 seconds at 8 Torr), 2) media exposed to intermittent hypoxia, 3) cells cultured with sustained hypoxia (8 Torr), 4) media exposed to sustained hypoxia and 4) standard tissue culture conditions (fresh DMEM media; reference).
Project description:We hypothesize that cultured macrophages directly exposed intermittent hypoxia will have a greater change in expression in genes related to inflammatory response than macrophages exposed to sustained hypoxia. We will evaluate gene expression using microarray analysis of RNA collected from RAW 264.7 macrophages cultured under the following environmental conditions: 1) 4 hours of intermittent hypoxia (2 minute cycles: 90 seconds at 40 Torr and 30 seconds at 8 Torr), 2) 4 hours of sustained hypoxia (8 Torr), and 3 ) standard tissue culture conditions (141 Torr; reference).
Project description:We analyzed gene expression via RNA-sequencing in medulla and C3-C6 cervical spinal cord microglia isolated from young adult rats exposed to gestational intermittent normoxia or gestational intermittent hypoxia
Project description:Background: Fetal hypoxia causes vital, systemic, developmental malformations in the fetus, particularly in the brain, and increases the risk of diseases in later life. We previously demonstrated that fetal hypoxia exposure increases the susceptibility of the neonatal brain to hypoxic-ischemic insult. Herein, we investigate the effect of fetal hypoxia on programming of cell-specific transcriptomes in the brain of neonatal rats.
Project description:This study examines the relationship between sleep apnea and glucose metabolism. Physiological studies have demonstrated that 5 days of exposure to intermittent hypoxia (similar to what occurs with sleep apnea) leads to significant improvements in glucose tolerance. Therefore, this study investigates the hypothesis that intermittent hypoxia may lead to upregulation of some novel peptide(s) that have a powerful glucose lowering action. Keywords: other