DNA-Based MRI Probes for Specific Detection of Chronic Exposure to Amphetamine in Living Brains

Liu, Christina; Ren, Jia Qian; Yang, Jinsheng; Liu, Charng-Ming; Mandeville, Joseph B.; Rosen, Bruce R.; Bhide, Pradeep G.; Yanagawa, Yuchio; Liu, Philip K.

doi:10.1523/jneurosci.2167-09.2009

Cited by 25 publications

(42 citation statements)

References 42 publications

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“…Although several other IEG promoters recently became popular markers of neuronal activity, the c-fos promoter is commonly used to validate findings. While the majority of imaging-based studies have focused on optical markers to monitor c-fos gene regulation, it should be noted that other means, such as magnetic resonance imaging (MRI), have been used to non-invasively monitor c- fos (Liu et al, 2007) and fosB mRNA in vivo (Liu et al, 2009). It has been suggested that genetically encoded reporters designed for MRI (Gilad et al, 2007; Bar-Shir et al, 2013), and driven by the c-fos promoter, can be applied for the real-time monitoring of gene expression in a similar manner.…”

Section: Discussionmentioning

confidence: 99%

Molecular Neuroimaging of Post-Injury Plasticity

2014

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Nerve injury induces long-term changes in neuronal activity in the primary somatosensory cortex (S1), which has often been implicated as the origin of sensory dysfunction. However, the cellular mechanisms underlying this phenomenon remain unclear. C-fos is an immediate early gene, which has been shown to play an instrumental role in plasticity. By developing a new platform to image real-time changes in gene expression in vivo, we investigated whether injury modulates the levels of c-fos in layer V of S1, since previous studies have suggested that these neurons are particularly susceptible to injury. The yellow fluorescent protein, ZsYellow1, under the regulation of the c-fos promoter, was expressed throughout the rat brain. A fiber-based confocal microscope that enabled deep brain imaging was utilized and local field potential were collected simultaneously. In the weeks following limb denervation in adult rats (n=10), sensory stimulation of the intact limb induced significant increases in c-fos gene expression in cells located in S1, both contralateral (affected, 27.6±3 cells) and ipsilateral (8.6±3 cells) to the injury, compared to controls (n=10, 13.4±3 and 1.0±1, respectively, p-value <0.05). Thus, we demonstrated that injury activates cellular mechanisms that are involved in reshaping neuronal connections and this may translate to neurorehabilitative potential.

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Section: Discussionmentioning

confidence: 99%

Molecular Neuroimaging of Post-Injury Plasticity

2014

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“…We then co-stained Cy2-labeled rabbit polyclonal IgG against glial fibrillary acidic protein (GFAP, Z0334, Dako) or Cy3-labeled polyclonal IgG against ionized calcium-binding adaptor molecule 1 (IBA1, ab5076, Abcam); we used Cy2-labeled monoclonal IgG against NeuN (A60, Millipore) or Cy3-labeled goat IgG against GFAP (clone C-19, Santa Cruz) for progenitor cells. Nucleic acids were stained with DAPI (1:500 dilution) [18]. To examine HDAC5 mRNA expression using Cy3-sODN (see below), transgenic mice ( n = 3) underwent icv puncture 1 week before they were administered Cy3-sODN (120 pmol in 0.1 ml, i.p.)…”

Section: Methodsmentioning

confidence: 99%

“…Four hours after amphetamine administration we obtained brain samples and froze them by slow cooling with liquid nitrogen. After staining slices of brain tissue (25 μm in thickness) with 0.5% Hoechst for nucleic acid, we obtained photographs using the same technique and equipment described above [18]. …”

Section: Methodsmentioning

confidence: 99%

“…We have developed NPs that specifically target two segments of HDAC5 mRNA: miD2861 and hdac5AS2. We conjugated SPION (core diameter 5–10 nm, hydrodynamic diameter 30 ± 20 nm) via Schiff-base reduction with biotinylated miD2861 or hdac5AS2 [18]. Upon binding to gene transcripts, these NPs produced target-specific signal reduction in T2*-weighted MR images [19–21], which we converted to R2* (1/s) for quantitation.…”

Section: Introductionmentioning

confidence: 99%

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Epigenetics of amphetamine-induced sensitization: HDAC5 expression and microRNA in neural remodeling

Liu

2016

J Biomed Sci

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BackgroundHistone deacetylase (HDAC) activities modify chromatin structure and play a role in learning and memory during developmental processes. Studies of adult mice suggest HDACs are involved in neural network remodeling in brain repair, but its function in drug addiction is less understood. We aimed to examine in vivo HDAC5 expression in a preclinical model of amphetamine-induced sensitization (AIS) of behavior. We generated specific contrast agents to measure HDAC5 levels by in vivo molecular contrast-enhanced (MCE) magnetic resonance imaging (MRI) in amphetamine-naïve mice as well as in mice with AIS. To validate the MRI results we used ex vivo methods including in situ hybridization, RT-PCR, immunohistochemistry, and transmision electron microscopy.MethodsWe compared the expression of HDAC5 mRNA in an acute exposure paradigm (in which animals experienced a single drug exposure [A1]) and in a chronic-abstinence-challenge paradigm (in which animals were exposed to the drug once every other day for seven doses, then underwent 2 weeks of abstinence followed by a challenge dose [A7WA]). Control groups for each of these exposure paradigms were given saline. To delineate how HDAC5 expression was related to AIS, we compared the expression of HDAC5 mRNA at sequences where no known microRNA (miR) binds (hdac5AS2) and at sequences where miR-2861 is known to bind (miD2861). We synthesized and labeled phosphorothioated oligonucleic acids (sODN) of hdac5AS2 or miD2861 linked to superparamagentic iron oxide nanoparticles (SPION), and generated HDAC5-specific contrast agents (30 ± 20 nm, diameter) for MCE MRI; the same sequences were used for primers for TaqMan® analysis (RT-qPCR) in ex vivo validation. In addition, we used subtraction R2* maps to identify regional HDAC5 expression.ResultsNaïve C57black6 mice that experience acute exposure to amphetamine (4 mg/kg, by injection intraperitoneally) show expression of both total and phosphorylated (S259) HDAC5 antigens in GFAP+ and GFAP− cells, but the appearance of these cells was attenuated in the chronic paradigm. We found that MCE MRI reports HDAC5 mRNA with precision in physiological conditions because the HDAC5 mRNA copy number reported by TaqMan analysis was positively correlated (with a linear coefficient of 1.0) to the ΔR2* values (the frequency of signal reduction above background, 1/s) measured by MRI. We observed SPION-mid2861 as electron dense nanoparticles (EDNs) of less than 30 nm in the nucleus of the neurons, macrophages, and microglia, but not in glia and endothelia. We found no preferential distribution in any particular type of neural cells, but observed scattered EDNs of 60–150 nm (dia) in lysosomes. In the acute paradigm, mice pretreated with miD2861 (1.2 mmol/kg, i.p./icv) exhibited AIS similar to that exibited by mice in the chronic exposure group, which exhibited null response to mid2861 pretreatment. Moreover, SPION-miD2861 identified enhanced HDAC5 expression in the lateral septum and the striatum after amphetamine, where we found neurprogenitor cel...

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“…In addition, the GABAergic system is also modified by Ket or Amph in the motor cortex, somatosensory cortex, and striatum [12,21,22]. The key enzyme of GABA synthesis, glutamate decarboxylase 67 (GAD 67 ), is commonly used as a biomarker for GABAergic neurons, and certain properties of GAD 67 -positive cells are altered by Ket or Amph treatments [23,24]. The interplay of the two drugs in different neurotransmission systems thus warrants detailed study.…”

Section: Introductionmentioning

confidence: 99%

Behavioral and Neurochemical Changes Induced by Repetitive Combined Treatments of Ketamine and Amphetamine in Mice

2014

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The combined abuse of recreational drugs such as ketamine (Ket) and amphetamine (Amph) should be seriously considered important social and health issues. Numerous studies have documented the behavioral and neurochemical changes associated with polydrug administration; however, most studies have only examined the acute effects. The consequences following chronic repetitive polydrug use are less studied. In the present study, intraperitoneal injections of saline, Amph (5 mg/kg), low dose Ket (LK, 10 mg/kg), high dose Ket (HK, 50 mg/kg), or Amph plus LK or HK (ALK or AHK) were conducted twice a day for three consecutive days, and one final treatment was administered on day 4. After seven total treatments, animal behaviors, including locomotion, stereotypy and ataxia, were examined in a novel open field. The expression of GAD67 and dopamine (DA) levels were assessed in the striatum and motor-related cortices using immunohistochemistry and high-performance liquid chromatography. Drug-induced hyperactivities and Amph-mediated potentiation of Ket-triggered ataxia manifested after repeated drug treatments. A significant increase in the number of GAD67-positive puncta in the striatum and motor-related cortices was observed, suggesting a neural adaptive change in the GABAergic system. Four hours after the final treatment, while the behavioral hyperactivities had ceased, considerable changes were still evident in the motor-related cortices, suggesting modulation to the DAergic system. Together, our results show the interactive effects of these two drugs in behavioral and neurochemical aspects and neural adaptive changes in the GABAergic and DAergic systems.

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DNA-Based MRI Probes for Specific Detection of Chronic Exposure to Amphetamine in Living Brains

Cited by 25 publications

References 42 publications

Molecular Neuroimaging of Post-Injury Plasticity

Molecular Neuroimaging of Post-Injury Plasticity

Epigenetics of amphetamine-induced sensitization: HDAC5 expression and microRNA in neural remodeling

Behavioral and Neurochemical Changes Induced by Repetitive Combined Treatments of Ketamine and Amphetamine in Mice

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