Effects of PAMAM dendrimers in the mouse brain after a single intranasal instillation
Ontology highlight
ABSTRACT: The in vivo effects of nasal exposure to polyamidoamine (PAMAM) dendrimers on their effects on gene expression in the mouse brain. A single dose of PAMAM dendrimers or saline (control) was intranasally administered to 8-week old male BALB/c mice. PAMAM-induced gene expression in the olfactory bulb, hippocampus, and cerebral cortex was measured at 24 hours after exposure to doses of 0, 0.15 mg/kg b.w. Pooled RNA from six independent experiments were analyzed at each time.
Project description:The in vivo effects of nasal exposure to polyamidoamine (PAMAM) dendrimers on their effects on gene expression in the mouse brain. A single dose of PAMAM dendrimers or saline (control) was intranasally administered to 8-week old male BALB/c mice.
Project description:Nowadays, drug abuse and addiction are serious public health problems in the USA. Methamphetamine (METH) is one of the most abused drugs, which is known to cause brain damage from repeated exposure on human. Herein, a proteomic study was applied to evaluate METH-induced brain protein dynamics following a two-week chronic regimen of escalating dose of METH exposure. Proteins were extracted from rat brain hippocampal and olfactory bulb tissues and subjected to liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Both shotgun and targeted proteomic analysis were performed. Protein quantitation was initially based on comparing the spectral counts between METH exposed animals and their control counterparts. Quantitative differences were further confirmed through multiple reaction monitoring (MRM) LC-MS/MS experiments. According to the quantitative results, the expression of 18 proteins (11 in hippocampal proteome, 7 in olfactory bulb proteome) were shown a significant alteration as a result of exposure of rats to METH. 13 of these proteins were up-regulated after METH exposure while 5 of were down-regulated. The altered proteins belonging to different structural and functional families were involved in processes such as cell death, inflammation, oxidation, and apoptosis.
Project description:Olfactory sensory neurons distinguish a large variety of odor molecules and direct the information through their axons to the olfactory bulb, the first site for the processing of olfactory information in the brain. Olfaction is very important for most mammals for the maintenance of a good quality of life. Accumulating evidences endorse that olfactory sensory decline is connected with neurodegenerative disorders including schizophrenia, depression, multiple sclerosis, Huntington's, Alzheimer's and Parkinson's diseases. For several decades, neuroanatomical, volumetric, and histological approaches have been the gold standard techniques employed to characterize the olfactory bulb functionality. Diagnosis and treatment of olfactory dysfunction remain significant health care challenges to society. Novel strategies and clues that assist in the identification of biomarker and drug development for aid in the prevention and cure of neurological diseases are necessary. However, little attention has been focused specifically on the molecular composition of the olfactory bulb from the perspective of proteomics. To this end, an in-depth mapping of the olfactory bulb proteome was carried out using high resolution tandem mass spectrometry, revealing a repertoire of 7,754 proteins. A large proportion of the identified proteins were predicted to be involved in diverse biological processes including signal transduction, metabolism, transport, olfaction and protein synthesis. Pathway analysis of the identified proteins shows that, these proteins are predominantly involved in metabolic and neural processes, chromatin modeling, and synaptic vesicle transport associated with neuronal transmission. In total, our study offers valuable understandings into the molecular composition of the human olfactory bulb proteome that could possibly help neuroscience community to understand the olfactory bulb better and open avenues for intervention strategies for olfactory dysfunction in the future.
Project description:There is an emerging concern that particulate air pollution increases the risk of cranial nerve disease onset. Small nanoparticles, mainly derived from diesel exhaust particles reach the olfactory bulb by their nasal depositions. It has been reported that diesel exhaust inhalation causes inflammation of the olfactory bulb and other brain regions. However, these toxicological studies have not evaluated animal rearing environment. We hypothesized that rearing environment can change mice phenotypes and thus might alter toxicological study results. In this study, we exposed mice to diesel exhaust inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days after rearing in a standard cage or environmental enrichment conditions. Microarray analysis found that expression levels of 112 genes were changed by diesel exhaust inhalation. Functional analysis using Gene Ontology revealed that the dysregulated genes were involved in inflammation and immune response. This result was supported by pathway analysis. Quantitative RT-PCR analysis confirmed 10 genes. Interestingly, background gene expression of the olfactory bulb of mice reared in a standard cage environment was changed by diesel exhaust inhalation, whereas there was no significant effect of diesel exhaust exposure on gene expression levels of mice reared with environmental enrichment. The results indicate for the first time that the effect of diesel exhaust exposure on gene expression of the olfactory bulb was influenced by rearing environment. Rearing environment, such as environmental enrichment, may be an important contributive factor to causation in evaluating still undefined toxic environmental substances such as diesel exhaust. RNA sample was taken from olfactory bulb of 56-day-old mouse received diesel exhaust (DE) inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days, while control RNA was taken from mouse received clean air, after rearing in a standard cage or environmental enrichment conditions. Comparisons among groups were made by one-color method with normalized data from Cy3 channels for data analysis.
Project description:Nanoparticulate matter activates the aryl hydrocarbon receptor (AhR) pathway in the respiratory system in a process involving the AhR nuclear translocator (ARNT) and cytochrome P450 family 1, member A1 (CYP1A1). We examined changes in AhR-related pathways following intranasal instillation of nanoparticulate matter in the olfactory bulb and cerebral cortex. Twice a day for 5 days per week for 1 week or 2 weeks, 8-week-old Sprague-Dawley rats were intranasally instilled with 10 µL nanoparticulate matter (nano group; n = 36). An equal volume of saline was intranasally instilled in control rats (n = 36). One week after intranasal instillation, olfactory function and Y-maze tests were performed. The expression levels of AhR in the olfactory bulb and temporal cortex were analyzed using western blotting and immunofluorescence assays. The expression levels of AhR, CYP1A1, inducible nitric oxide synthase (iNOS), and five genes encoding cation transporters (ARNT, ATP7B, ATPB1, OCT1, and OCT2) in the olfactory bulb were analyzed using quantitative reverse transcription. The olfactory discrimination capability was reduced in the nano group compared with the control group. Proportional changes in the Y-maze test were not significantly different between the nano and control groups. AhR mRNA and protein expression in the olfactory bulb increased 1.71-fold (P < 0.001) and 1.60-fold (P = 0.008), respectively. However, no significant changes were observed in the temporal cortex. In the olfactory bulb, the expression of ARNT, ATP7B, ATPB1, and OCT2 was downregulated. CYP1A1 and iNOS expression in the olfactory bulb was upregulated compared with that in the temporal cortex. The intranasal instillation of nanoparticulate matter decreased the olfactory discrimination ability, which was accompanied by upregulation of AhR expression and downregulation of cation transporters in the olfactory bulb.
Project description:To investigate the effects of rabies infection on neuronal gene expression, we compared gene profiles of rabies infected and non-infected GABAergic neurons in the Zebrafish olfactory bulb.
Project description:Splenic immune function was enhanced in diet-induced-obese (DIO) mice caused by Escherichia coli. The changes in spleen function on apoptosis were still unknown. Two hundred mice in groups Lean-E. coli and DIO-E. coli were intranasal instillation of E. coli. And another two hundred mice in groups Lean-PBS and DIO-PBS were given phosphate-buffered saline (PBS). Subsequently, spleen histology was analyzed. Then the rates of spleen cell (SC) apoptosis, and expression of the genes and proteins of Bcl-2, Bax, caspase-3 and caspase-9 were quantified in each group at 0 h (uninfected), 12 h, 24 h, and 72 h postinfection. The SC apoptosis rates of the DIO-E. coli groups were lower than those of the DIO-PBS groups at 12, 24 and 72 h (p < 0.05). Anti-apoptotic Bcl-2 expression gene and protein of the DIO-E. coli groups were higher than those of the DIO-PBS groups (p < 0.05). Gene expressions of pro-apoptotic Bax, caspase-3 and caspase-9 of the DIO-E. coli groups were lower than those of DIO-PBS groups at 12, 24 and 72 h (p < 0.05). The SC apoptosis rates of the Lean-E. coli groups were higher than those of the Lean- PBS groups at 12 h and 24 h (p < 0.05). Interestingly, the SC apoptosis rates in the DIO-E. coli groups were lower than those of the Lean-E. coli groups at 12 h (p < 0.05). In conclusion, our results suggested that the DIO mice presented stronger anti-apoptotic abilities than Lean mice in non-fatal acute pneumonia induced by E. coli infection, which is more conducive to protecting the spleen and improving the immune defense ability of the body.
Project description:Rodent studies have indicated that gestational and perinatal bisphenol A (BPA) exposure increase the risk of developing breast cancer during adulthood. In contrast, some dietary compounds such as genistein (GEN) and indole 3-carbinol (I3C) present potential protective effects against inducing hormone-dependent cancers, including that of the mammary gland. Thus, we aimed to evaluate the role of these dietary compounds on early mammary gland development and carcinogenesis in female Sprague-Dawley offspring. Pregnant Sprague-Dawley (SD) rats were treated with BPA at 25 or 250µg/kg b.w./day by gavage from gestational day (GD) 10 to 21 with or without dietary GEN (250 mg/kg chow, ~5.5 mg/kg b.w./day) or I3C (2000 mg/kg chow, ~45.0 mg/kg b.w./day). At post-natal day (PND) 21, some female offspring from different litters were euthanized for mammary gland development and gene expression analyses while other female offspring received a single dose of N-methyl-N-nitrosourea (MNU) for mammary carcinogenesis initiation. The findings this study indicated the prenatal exposure to BPA, GEN and I3C did not significantly alter ductal elongation, number of terminal end buds (TEB) or cell proliferation, and estrogen receptor alpha (ER-α) immunostaining expression in epithelial mammary cells at PND 21. BPA treatment modulated the expression of several genes, but these changes were not associated with a dose dependent response. Dietary GEN and I3C treatment causally and consistent with the mammary gland structures outcomes. Besides, maternal BPA exposure associated with dietary GEN and I3C did not alter the susceptibility to the mammary cancer development in adulthood when the carcinogen was administered in a window of immature mammary gland development.
Project description:To better understand the molecular basis of the reproductive health effects of bisphenol A (BPA) on humans, a genome-wide screening was applied to identify novel targets of low-dose bisphenol A exposure in huamn skin fibroblast cells (hSFCs) derived from hypospadias patient children. Three hSFCs were collected at National Research Institute for Child Health and Development, Japan. Gene expression profiles of hSFCs were measured at 24 hours after exposure to 10nM BPA, 0.01nM 17β-estradiol (E2) and 1nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Differentially expressed genes following chemical treatments were identified by unpaired Student’s t test with P values cut off by 0.05 and fold change of more than 1.2 and selected for the network generation and pathway analysis using Ingenuity Pathways Analysis (IPA) program. As the result, 71 genes (42 downregulated and 29 upregulated), 814 genes (371 downregulated and 443 upregulated), and 824 genes (344 downregulated and 480 upregulated) were identified significantly differently expressed in response to BPA, E2, and TCDD, respectively. The network analysis indicated that the most associated network fuctions of genes genes with altered expression profile derived from microarray analysis were “Endocrine System Disorders, Gastrointestinal Disease, Genetic Disorder”, “Cellular Growth and Proliferation, Skeletal and Muscular System Development and Function, Cell Cycle”, and “Post-Translational Modification, Genetic Disorder, Hematological Disease” in response to BPA, E2, and TCDD, respectively. Gene expression profiles of 3 hSFCs derived from hypospadias patient children were measured at 24 hours after exposure to 10nM BPA, 0.01nM E2 and 1nM TCDD.
Project description:This study evaluated transcriptional effects of nanomaterials that have been proposed for use as platforms for drug delivery. We tested SiO2 that had been surface modified to have a positive zetapotential of different geometries as well PAMAM dendrimers with different surface charges. We tested these materials on human aortic endothelial cells (HAECs) since we were interested in determining if there was a toxicogenomic response in endothelial cells that may come into contact with drug delivery nanoplatforms. The most pronounced transcriptional response resulted from the SiO2 treatement - the most prevelant responses were cell cycle, lipid metabolism and pro-inflammatory responses - with fewer responses from the PAMAM dendrimers. The lipid metabolism responses may relate to teh positive surface character as this response was not observed in the G3.5-COOH dendrimers. Indeed, the G3.5-COOH dendrimers were non-toxic and did not demonstrate any consistent transcriptional response. Primary human aortic endothial cells (HAECs) were grown in 6 well plates (in 2 ml of medium) until they were >80% confluent by visual inspection. Daily media changes allowed continued growth for HAECs that demonstrate contact inhibition. The cells were then incubated with nanomaterials: surface modified SiO2 with worm and sphere goemetries (the spheres were 200 nm in diameter and the worm's cylindrical diameter 200 nm and the length was ~ 1000 nm); and PAMAM dendrimers with different surface charges (G3.5-COOH are negative and G4-NH2 are positive). RNA was collected after 4 and 24 hrs (one SiO2 worm sample was at 1.5 hrs due to space available on the 4-pack microarrays). Triplicate biological samples (indicated by the 'a', 'b', and 'c' designations in the sample names) were evaluated for gene expression changes by microarray analysis.