Maternal Nicotine Exposure Alters Hippocampal Microglia Polarization and Promotes Anti-Inflammatory Signaling in Juvenile Offspring in Mice
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ABSTRACT: To further detect possible developmental neurotoxic effects of nicotine in offspring and underlying mechanism, whole genome microarray analysis of the expression profile of hippocampus was performed on PND 20. Significant alterations in the expression of genes related to inflammatory, neurotransmitter and synapsis were observed in the hippocampus after maternal nicotine exposure, as compared to the vehicle control.
Project description:Nicotine intake, whether through tobacco smoking or e-cigarettes, remains a global health concern. An emerging preclinical literature indicates that parental nicotine exposure produces behavioral, physiological, and molecular changes in subsequent generations. However, the heritable effects of voluntary parental nicotine taking are unknown. Here, we show increased acquisition of nicotine taking in male and female offspring of sires that self-administered nicotine. In contrast, self-administration of sucrose and cocaine were unaltered in male and female offspring suggesting that the intergenerational effects of paternal nicotine taking may be reinforcer specific. Further characterization revealed memory deficits and increased anxiety-like behaviors in drug-naïve male, but not female, offspring of nicotine-experienced sires. Using an unbiased, genome-wide approach, we discovered that these phenotypes were associated with decreased expression of Satb2, a transcription factor known to play important roles in synaptic plasticity and memory formation, in the hippocampus of nicotine-sired male offspring. This effect was sex-specific as no changes in Satb2 expression were found in nicotine-sired female offspring. Finally, increasing Satb2 levels in the hippocampus prevented the escalation of nicotine intake and rescued the memory deficits associated with paternal nicotine taking in male offspring. Collectively, these findings indicate that paternal nicotine taking produces heritable sex-specific molecular changes that promote addiction-like phenotypes and memory impairments in male offspring. To characterize the molecular changes associated with the heritable effects of paternal nicotine taking, an unbiased, whole-genome analysis was used to characterize the hippocampal transcriptome of drug-naïve F1 males
Project description:Paternal nicotine exposure can alter phenotypes in future generations. To explore whether paternal nicotine exposure affects the hepatic repair to chronic injury which would lead to hepatic fibrosis in offspring, we establish a paternal effect model based on nicotine exposure in mice.
Project description:Although it is increasingly accepted that some paternal environmental conditions can influence phenotypes in future generations, it remains unclear whether phenotypes induced in offspring represent specific responses to particular aspects of the paternal exposure history, or whether they represent a more generic response to paternal “quality of life”. To establish a paternal effect model based on a specific ligand-receptor interaction and thereby enable pharmacological interrogation of the offspring phenotype, we explored the effects of paternal nicotine administration on offspring phenotype in mouse. We show that paternal exposure to chronic nicotine induced a broad protective response to xenobiotic exposure in the next generation. This effect manifested as increased survival following an injection of toxic levels of nicotine, was specific to male offspring, and was only observed after these offspring were first acclimated to low levels of nicotine for a week. Importantly, offspring xenobiotic resistance was documented not only for toxic nicotine challenge, but also for toxic cocaine challenge, indicating that paternal nicotine exposure reprograms offspring to become broadly resistant to environmental toxins. Mechanistically, the reprogrammed state was characterized by enhanced clearance of nicotine in drug-acclimated animals, and we found that isolated hepatocytes displayed upregulation of enzymes that metabolize xenobiotics. Taken together, our data show that paternal nicotine exposure induces a protective phenotype in offspring by enhancing metabolic tolerance to xenobiotics in the environment.
Project description:The long-term goal of this project is to establish whether and how chronic nicotine exposure affects nervous system function. The biological targets of nicotine action are diverse members of the superfamily of neurotransmitter-gated ion channels called nicotinic acetylcholine receptors (nAChR). nAChR play multiple, critical roles in chemical signaling throughout the brain and body. They also must be involved in nicotine dependence, which drives tobacco product use responsible for tremendous economic and personal costs. To define changes in gene expression induced by nicotine exposure in a model neuronal cell lines expressing at least two nicotinic receptor subtypes. Nicotine exposure exerst at least some of its effects on nervous system function by altering gene expression. Cells of the SH-SY5Y human neuroblastoma will be exposed to an efficacious dose of nicotine or to control medium for two different periods. Keywords: time-course
Project description:The long-term goal of this project is to establish whether and how chronic nicotine exposure affects nervous system function. The biological targets of nicotine action are diverse members of the superfamily of neurotransmitter-gated ion channels called nicotinic acetylcholine receptors (nAChR). nAChR play multiple, critical roles in chemical signaling throughout the brain and body. They also must be involved in nicotine dependence, which drives tobacco product use responsible for tremendous economic and personal costs. To define changes in gene expression induced by nicotine exposure in a model neuronal cell lines expressing at least two nicotinic receptor subtypes. Nicotine exposure exerst at least some of its effects on nervous system function by altering gene expression. Cells of the SH-SY5Y human neuroblastoma will be exposed to an efficacious dose of nicotine or to control medium for two different periods.
Project description:Accumulating evidence reveal that maternal smoking or perinatal nicotine replacement therapy impairs hippocampal neurogenesis, neural development, and cognitive behaviors in the offspring. Microglia is a source of non-neural regulation of neuronal development and postnatal neurogenesis. In this study, we explored the impact of nicotine on the microglia during the development of hippocampus. Developmental nicotine exposure in a mouse model was conducted by supplementing nicotine in the drinking water to mother mice during gestation and lactation period. We found that juvenile offspring with maternal nicotine exposure presented physical and neurobehavioral development delay and an increase in anxiety-like behavior in the open field test on postnatal day (PND) 20. To further detect possible developmental neurotoxic effects of nicotine in offspring and underlying mechanism, whole genome microarray analysis of the expression profile of the hippocampus was performed on postnatal day 20. Significant alterations in the expression of genes related to inflammatory, neurotransmitter, and synapsis were observed in the hippocampus after maternal nicotine exposure, as compared to the vehicle control. Concurrently, an increase in microglial markers and the presence of M2 polarity state in the hippocampus of the nicotine offspring were observed by histological analysis and confocal z-stacking scanning. The M2 microglial polarization state was further confirmed with in vitro primary microglia culture by cytokine array, and double-positive expression of BDNF/Iba1 in microglia by immunohistochemical staining in the juvenile offspring hippocampus was visualized. We also found that nicotine offspring showed an increase of neurite length in the molecular layer and CA1 by Tuj1 staining, as well as an increase in the expression of synapse associated protein, PSD95, but the expression of NeuroD1 in CA1 and CA3 reduced. In summary, maternal nicotine exposure dysregulates immune-related genes expression by skewing the polarity of M2 microglia in the hippocampus, which may cause abnormal cognitive and behavioral performance in the offspring.
Project description:To examine irreversible changes in the developing brain following seizures, juvenile inbred mice were intraperitoneally injected with kainate and nicotine. Keywords: seizure induction
Project description:Adult (14 weeks old) Sprague-Dawley rats showing at least three consecutive normal periods (4 day) of estrous cycles were randomly assigned to four groups: 1: saline, 2: nicotine (6 mg/kg), 3: OC and 4: nicotine (6 mg/kg) + OC. Rats were exposed to these treatments for a month. At the end of treatments, hippocampus was obtained, immediately frozen in liquid nitrogen. We are sending one side of hippocampi to Southeast Center for Integrated Metabolomics for analysis at the University of Florida.