Investigating The Role of AEG-1 in Mouse Models of Pain

Background: Astrocyte Elevated Gene 1 (AEG-1) is a multifunctional protein shown to be a regulator of transcription and multiple intracellular signaling pathways. The role of AEG-1 in cellular inflammation appears to be primarily facilitated by its direct interaction with the transcription factor NFκB, transcriptional regulator of inflammatory cytokines. May be have a potential role in models of pain, particularly chronic inflammatory and chemotherapy induced peripheral neuropathy (CIPN). Methods: C57BL6/J male and female mice, 8-14 weeks old. AEG-1 wild type (WT) and global knockout (KO) male and female mice, 8-14 weeks old. Chronic Inflammatory Pain induced via i.pl. injection of 50% Freund\u27s Complete Adjuvant (CFA) or vehicle into mouse right hind paw. CIPN induced via four 8 mg/kg, i.p. injections of Paclitaxel or vehicle (Toma, et. al). Mechanical hypersensitivity assessed via von frey filaments. Acetone Test was used to assess cold sensitivity. mRNA transcripts collected from tissues were measured via qRT-PCR. Results: AEG-1 KO mice displayed protection from CFA induced mechanical hypersensitivity, thermal sensitivity, and reduces paw edema compare to WT mice. AEG-1 KO mice displayed enhanced recovery from paclitaxel induced mechanical hypersensitivity and cold sensitivity compared to WT mice. AEG-1 expression levels in the periaqueductal grey, spinal cord, and L4-6 corresponding dorsal root ganglia collected from C57BL6/J mice treated with 8mg/Kg paclitaxel or 50% CFA (3 days post injection) showed no difference from control groups. Conclusions: Our data suggest that AEG-1 may be involved in inflammatory and CIPN related nociception in C57BL6/J mice.https://scholarscompass.vcu.edu/gradposters/1093/thumbnail.jp

Function Of Human α3β4α5 Nicotinic Acetylcholine Receptors Is Reduced By The β5(D398N) Variant

Genome-wide studies have strongly associated a non-synonymous polymorphism (rs16969968) that changes the 398th amino acid in the nAChR α5 subunit from aspartic acid to asparagine (D398N), with greater risk for increased nicotine consumption. We have used a pentameric concatemer approach to express defined and consistent populations of α3β4α5 nAChR in Xenopus oocytes. α5(Asn-398; risk) variant incorporation reduces ACh-evoked function compared with inclusion of the common α5(Asp-398) variant without altering agonist or antagonist potencies. Unlinked α3, β4, and α5 subunits assemble to form a uniform nAChR population with pharmacological properties matching those of concatemeric α3β4* nAChRs. α5 subunit incorporation reduces α3β4* nAChR function after coinjection with unlinked α3 and β4 subunits but increases that of α3β4α5 versus α3β4-only concatemers. α5 subunit incorporation into α3β4* nAChR also alters the relative efficacies of competitive agonists and changes the potency of the non-competitive antagonist mecamylamine. Additional observations indicated that in the absence of α5 subunits, free α3 and β4 subunits form at least two further subtypes. The pharmacological profiles of these free subunit α3β4-only subtypes are dissimilar both to each other and to those of α3β4α5 nAChR. The α5 variant-induced change in α3β4α5 nAChR function may underlie some of the phenotypic changes associated with this polymorphism. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc

Astrocyte Elevated Gene-1 (AEG-1) Deletion Selectively Enhances the Antinociceptive Effects of Morphine

Background: Opioids are a class of drugs that are utilized in clinical settings to alleviate acute and chronic pain, but can often lead to development of tolerance, addiction and overdose following prolonged usage. Opioids such as morphine function by activating endogenous µ opioid receptors, which are located in various tissues throughout the body. Astrocyte Elevated Gene-1 (AEG-1) is a multifunctional protein that regulates inflammation, myeloid cell activity and lipid metabolism. Studies have shown interactions and overlaps in cellular signaling between the inflammatory/immune responses and the endogenous opioid system which could suggest a role for AEG-1 in opioids effects. Our goal is to investigate the role of AEG-1 in morphine mediated pharmacological effects including analgesia. Methods: Adult AEG-1 global knockout (KO) and wild-type (WT) male and female mice (C57BL/6J background) were utilized to assess morphine-induced thermal antinociception (The tail immersion assay test), hyperlocomotion, gastrointestinal (GI) transit inhibition, and tolerance. GI transit was assessed via charcoal transit assay. Locomotor boxes were used to assess spontaneous activity in mice. Results: AEG-1 KO mice displayed increased thermal antinociception following acute and repeated morphine administration compared to their WT counterparts. Pretreatment with naloxone blocked the enhancement of morphine thermal antinociception in AEG-1 KO mice. In addition, chronic morphine treated AEG-1 KO mice displayed reduced morphine tolerance development compared to their WT counterparts. No significant differences in morphine-induced hyperlocomotion or GI transit inhibition were observed between AEG-1 KO and WT mice. Conclusions: Our data suggest that AEG-1 deletion enhances the antinociceptive effects of morphine and reduces tolerance to chronic morphine treatment. However, AEG-1 deletion does not impact morphine-induced locomotor activity of GI transit inhibition. Overall, our results suggest that AEG-1 may function as a modulator of the endogenous opioid system.https://scholarscompass.vcu.edu/uresposters/1413/thumbnail.jp

Genetic Approaches Identify Differential Roles for α₄β₂* Nicotinic Receptors in Acute Models of Antinociception in Mice

The effects of nicotine on the tail-flick and hot-plate tests were determined to identify nicotinic receptor subtypes responsible for spinally and supraspinally mediated nicotine analgesia in knockin mice expressing hypersensitive α4 nicotinic receptors (L9′S), in seven inbred mouse strains (C57BL/6, DBA/2, A/2, CBA/2, BALB/cByJ, C3H/HeJ, and 129/SvEv), and in two F1 hybrids (B6CBAF1 and B6D2F1). L9′S heterozygotes were ∼6-fold more sensitive to the antinociceptive effects of nicotine than the wild-type controls in the hot-plate test but not in the tail-flick assay. Large differences in the effects of nicotine were also observed with both tests for the seven mouse strains. A/J and 129 mice were 6- to 8-fold more sensitive than CBA and BALB mice. In addition, B6CBAF1 hybrid mice were even less sensitive than CBA mice. Nicotinic binding sites were measured in three spinal cord regions and the hindbrain of the inbred strains. Significant differences in cytisine-sensitive, high affinity [¹²⁵I]epibatidine binding site levels (α₂β₂* subtypes), but not in ¹²⁵I-α-bungarotoxin binding (α7* subtypes), were observed. Significant negative correlations between cytisine-sensitive [¹²⁵I]epibatidine binding and nicotine ED50 for both tests were noted. Our results indicate that α₄β₂* acetylcholine nicotinic receptors (nAChR) are important in mediating nicotine analgesia in supraspinal responses, while also showing that α₄β₂*-nAChR and at least one other nAChR subtype appear to modulate spinal actions

Aromatic L-Amino Acid Decarboxylase Deficiency Is a Cause of Long-Fasting Hypoglycemia

Objective/Context: Long-fasting hypoglycemia in children may be induced by neurotransmitter disorders. Case Report: A 5-year-old girl with a medical history of chronic diarrhea presented three episodes of severe hypoglycemia (20 mg/dL) between ages 3 and 5 years. She became pale and sweaty with hypothermia (33.5°C), bradycardia (45 bpm), and acidosis and presented a generalized seizure. During the 17-hour fast test performed to determine the etiology of her hypoglycemia, insulin and C-peptide were appropriately low, and human GH, IGF-I, cortisol, amino acids, and acylcarnitines were in the usual range for fasting duration. However, the presence of vanillactic and vanilpyruvic acids in urine led us to investigate the metabolism of dopamine and serotonin in the cerebrospinal fluid. Indeed, these results indicated an aromatic L-amino acid decarboxylase deficiency that impairs the synthesis of serotonin, dopamine, and catecholamines. The diagnosis was confirmed by the low aromatic L-amino acid decarboxylase (AADC) enzyme activity in plasma (5 pmol/min/mL; reference value, 20–130) and the presence of two heterozygous mutations, c.97G>C (p.V33L, inherited from her father) and c.1385G>C (p.R462P, inherited from her mother) in the DCC gene. She was supplemented with pyridoxine and raw cornstarch (1 g/kg) at evening dinner to reduce the night fast. The episodes of hypoglycemia and the chronic diarrhea were suppressed. Conclusion: Here is the first case report of long-fasting hypoglycemia due to a nontypical AADC deficiency. Hypoglycemia was severe, but the other neurological clinical hallmarks present in AADC-deficient patients were mild to moderate. Thus, neurotransmitter disorders should be considered in any patients presenting hypoglycemia with urine excretion of vanillactic acid

C57BL/6 Substrain Differences in Pharmacological Effects after Acute and Repeated Nicotine Administration.

Tobacco smoking is the major cause of disability and death in the United States and around the world. In addition, tobacco dependence and addiction express themselves as complex behaviors involving an interplay of genetics, environment, and psychological state. Mouse genetic studies could potentially elucidate the novel genes and/or gene networks regulating various aspects of nicotine dependence. Using the closely related C57BL/6 (B6) mice substrains, recent reports have noted phenotypic differences within C57BL/6J (B6J) and C57BL/6N (B6N) mice for some drugs of abuse: alcohol, opiates, and cocaine. However, the differences in nicotine\u27s effects have not yet been described in these substrains. We examined the phenotypic differences in these substrains following the acute and repeated administration of nicotine in several pharmacological measures, including locomotion (after acute and repeated exposure), body temperature, nociception, and anxiety-like behaviors. We report substrain differences in the pharmacological effects of acute and repeated nicotine administration in the B6 substrains. Overall, we show enhanced nicotine sensitivity to locomotion, hypothermia, antinociception, and anxiety-like behaviors in the B6J mouse substrain compared to B6N. In the repeated administration paradigm, both the B6N and B6J substrains showed no sensitized locomotor responses after repeated exposure to nicotine at the two doses tested. This study thus provides evidence that the B6 mouse substrains may be useful for genetic studies to elucidate some of the genetic variants involved in tobacco dependence and addiction

CARGC Briefs Volume I: ISIS Media

The essays that comprise CARGC Briefs Volume I: ISIS Media began their lives as presentations at a small, by-invitation workshop, “Emerging Work on Communicative Dimensions of Islamic State,” held on May 3-4, 2017 at the Center for Advanced Research in Global Communication at the Annenberg School for Communication. Consistent with CARGC’s mission to mentor early-career scholars, the workshop was a non-public event featuring graduate students, some affiliated with the Jihadi Networks of Communication and CultureS (JINCS) research group at CARGC, and others from around the United States and the world, in addition to postdocs and faculty members. Parameters were purposefully broad to encourage independent thought and intellectual exploration: contributors were asked to write short essays focusing on any single aspect of Islamic State that was part of their research. The result is a group of fascinating essays: using mostly primary sources (textual, visual, or audio-visual), examining several media platforms and modalities, considering multiple levels of theoretical deployment and construction, and shedding light on various aspects of Islamic State communication against the broad back drop of history, ideology and geopolitics, the following include some of the most innovative approaches to Islamic State to date, and promise a wave of fresh voices on one of the most important challenges to global order.https://repository.upenn.edu/cargc_briefs/1000/thumbnail.jp

Synthesis And Biological Evaluation Of Bupropion Analogues As Potential Pharmacotherapies For Smoking Cessation

Bupropion (2a) analogues were synthesized and tested for their ability to inhibit monoamine uptake and to antagonize the effects of human α3β4*, α4β2, α4β4, and α1 * nAChRs. The analogues were evaluated for their ability to block nicotine-induced effects in four tests in mice. Nine analogues showed increased monoamine uptake inhibition. Similar to 2a, all but one analogue show inhibition of nAChR function selective for human α3β4*-nAChR. Nine analogues have higher affinity at α3β4*-nAChRs than 2a. Four analogues also had higher affinity for α4β2 nAChR. Analogues 2r, 2m, and 2n with AD 50 values of 0.014,0.015, and 0.028 mg/kg were 87,81, and 43 times more potent than 2a in blocking nicotine-induced antinociception in the tail-flick test. Analogue 2x with IC50 values of 31 and 180 nM for DA and NE, respectively, and with IC50 of 0.62 and 9.8 μm for antagonism of α3β4 and α4β2 nAChRs had the best overall in vitro profile relative to 2a. © 2010 American Chemical Society