Project description:We developed a mouse model of NOWS that includes gestational and post-natal morphine exposure that encompasses the developmental equivalent of all three human trimesters of gestation. This exposure paradigm causes delayed developmental milestones and acute withdrawal phenotypes reminiscent of those observed in infants.
Project description:To investigate how exposure to morphine during the prenatal and early postnatal period affects the offspring prefrontal cortex in a mouse model We performed gene expression profiling analysis using data obtained from RNA-seq of offspring prefrontal cortical brain samples at postnatal day 21
Project description:Morphine is used to sedate critically ill infants to treat painful or stressful conditions associated with intensive care. Whether neonatal morphine exposure affects microRNA (miR) expression and thereby alters mRNA regulation is unknown. We tested the hypothesis that repeated morphine treatment in stress-exposed neonatal mice alters hippocampal mRNA and miR gene expression. C57BL/6 male mice were treated from postnatal day (P) 5 to P9 with morphine at 2 or 5 mg/kg ip bid (MS5) and then exposed to stress consisting of hypoxia (100% N2 1 min and 100% O2 5 min) followed by 2h maternal separation. Control mice were untreated and dam-reared. mRNA and microRNA expression profiling was performed on hippocampal tissues at P9. Overall, MS2 and MS5 morphine treatment altered expression of a total of 150 mRNAs (>1.5 fold change, P<0.05; 36 up, 114 down), and MS5 affected 63 mRNAs. The most upregulated mRNAs were fidgetin, arginine vasopressin, and resistin-like alpha, and the most down-regulated were defensin beta 11, aquaporin 1, calmodulin-like 4, chloride intracellular channel 6, and claudin 2. Gene Set Enrichment Analysis revealed that morphine treatment affected pathways related to cell cycle, membrane function, signaling, metabolism, cell death, transcriptional regulation, and immune response. MS5 decreased expression of miR-204-5p, miR-455-3p, miR-448-3p, and miR-574-3p.Nine morphine-responsive mRNAs that are involved in neurodevelopment, neurotransmission, and inflammation are predicted targets of the aforementioned differentially expressed microRNAs These data establish that morphine produces dose-dependent changes in both hippocampal mRNA and miR gene expression in stressed neonatal mice. If permanent, morphine–mediated neuroepigenetic effects may affect long-term hippocampal function, and this provides a mechanism for the neonatal morphine-related impairment of adult learning.
Project description:m6a modified RNA and unmodified RNA were quantified in primary neuronal cultures following either siRNA knockdown of Alkbh5 or chronic morphine exposure for 3 days. The goal was to identify mRNA that have m6A modifications following one or more treatment conditions.
Project description:Critically ill preterm infants experience multiple stressors while hospitalized. Morphine is commonly prescribed to ameliorate their pain and stress. We hypothesized that neonatal stress will have a dose-dependent effect on hippocampal gene expression, and these effects will be altered by morphine treatment. Male C57BL/6 mice were exposed to 5 treatment conditions between postnatal day 5 and 9: 1) Control, 2) mild stress + saline, 3) mild stress + morphine, 4) severe stress + saline and 5) severe stress + morphine. Hippocampal RNA was extracted and analyzed using Affymetrix Mouse Gene 1.0 ST Arrays. Single gene analysis and gene set analysis were used to compare groups with validation by qPCR. Stress resulted in enrichment of genes sets related to fear response, oxygen carrying capacity and NMDA receptor synthesis. Morphine downregulated gene sets related to immune function. Stress plus morphine resulted in enrichment of mitochondrial electron transport gene sets, and down-regulation of gene sets related to brain development and growth. We conclude that neonatal stress alone influences hippocampal gene expression, morphine alters a subset of stress-related changes in gene expression and influences other gene sets. Stress plus morphine show interaction effects not present with either stimulus alone. These changes may alter neurodevelopment. Male mice were exposed to 5 treatment conditions between postnatal day (P)5 and P9 (n=3/group), with birth recorded as P1. Litters were culled to n=7 maximum per dam. Groups included: 1) Untreated controls (CC), 2) mild stress + saline (MSS), 3) mild stress + morphine (MSM), 4) severe stress + saline (SSS) and 5) severe stress + morphine (SSM).
Project description:Critically ill preterm infants experience multiple stressors while hospitalized. Morphine is commonly prescribed to ameliorate their pain and stress. We hypothesized that neonatal stress will have a dose-dependent effect on hippocampal gene expression, and these effects will be altered by morphine treatment. Male C57BL/6 mice were exposed to 5 treatment conditions between postnatal day 5 and 9: 1) Control, 2) mild stress + saline, 3) mild stress + morphine, 4) severe stress + saline and 5) severe stress + morphine. Hippocampal RNA was extracted and analyzed using Affymetrix Mouse Gene 1.0 ST Arrays. Single gene analysis and gene set analysis were used to compare groups with validation by qPCR. Stress resulted in enrichment of genes sets related to fear response, oxygen carrying capacity and NMDA receptor synthesis. Morphine downregulated gene sets related to immune function. Stress plus morphine resulted in enrichment of mitochondrial electron transport gene sets, and down-regulation of gene sets related to brain development and growth. We conclude that neonatal stress alone influences hippocampal gene expression, morphine alters a subset of stress-related changes in gene expression and influences other gene sets. Stress plus morphine show interaction effects not present with either stimulus alone. These changes may alter neurodevelopment.
Project description:Morphine addiction causes major medical and social problems worldwide. Chronic morphine exposure results in the development of behavioral sensitization, accompanied by the disruption of brain homeostasis. As a key brain reward region, nucleus accumbens (NAc) plays a central role in brain reward mechanisms. However, the contribution of morphine exposure to NAc is poorly understood. Here we indicated that chronic morphine exposure induced neuroinflammation, abnormal neuronal physiology, and dysregulation of glycolytic metabolism in NAc. In summary, our findings illustrate the effects of morphine in NAc, and provide a new insight for development of future morphine addiction therapeutics.
Project description:A great number of studies have investigated changes induced by morphine exposure in gene expression using several experimental models. In this study, we examined gene expression changes during chronic exposure to morphine during maturation and differentiation of zebrafish CNS. Our study identified different functional classes of genes and individual candidates involved in the mechanisms underlying susceptibility to morphine actions related to CNS development. These results open new lines to study the treatment of pain and the molecular mechanisms involved in addiction. We also found a set of zebrafish-specific morphine-induced genes, which may be putative targets in human models for addiction and pain processes. Zebrafish embryos were divided into two experimental groups: control embryos and embryos at 5 hpf exposed to 10 nM morphine and collected at 24 hpf (covering the complete embryogenesis). Morphine was administered to the embryos in their water environment, i.e., diluted in E3 embryonic medium. The exposition to begun at the stage of 5 hpf (end of blastula) is continuous, in order to study the chronic effects of the exposure to drug. Microarray experiments were performed using six replicates for each condition, which contained the RNA of approximately one hundred embryos to minimize the influence of potential individual differences between the animals and technical variation introduced by tissue preparation. We previously reported that a concentration of 10 nM morphine is the highest concentration that can be used without a toxic effect on the embryos, and close to 5% of the morphine diluted in the E3 medium is detected in the embryo.