Adenosine A2A receptor blockade prevents cisplatin-induced impairments in neurogenesis and cognitive function.

Chemotherapy-induced cognitive impairment (CICI) has emerged as a significant medical problem without therapeutic options. Using the platinum-based chemotherapy cisplatin to model CICI, we revealed robust elevations in the adenosine A2A receptor (A2AR) and its downstream effectors, cAMP and CREB, by cisplatin in the adult mouse hippocampus, a critical brain structure for learning and memory. Notably, A2AR inhibition by the Food and Drug Administration-approved A2AR antagonist KW-6002 prevented cisplatin-induced impairments in neural progenitor proliferation and dendrite morphogenesis of adult-born neurons, while improving memory and anxiety-like behavior, without affecting tumor growth or cisplatin's antitumor activity. Collectively, our study identifies A2AR signaling as a key pathway that can be therapeutically targeted to prevent cisplatin-induced cognitive impairments.

Neurologic Effects of Gadolinium Retention in the Brain after Gadolinium-based Contrast Agent Administration.

Background Concerns over the neurotoxic potential of retained gadolinium in brain tissues after intravenous gadolinium-based contrast agent (GBCA) administration have led to pronounced worldwide use changes, yet the clinical sequelae of gadolinium retention remain undefined. Purpose To assess clinical and neurologic effects and potential neurotoxicity of gadolinium retention in rats after administration of various GBCAs. Materials and Methods From March 2017 through July 2018, 183 male Wistar rats received 20 intravenous injections of 2.5 mmol per kilogram of body weight (80 human equivalent doses) of various GBCAs (gadodiamide, gadobenate, gadopentetate, gadoxetate, gadobutrol, gadoterate, and gadoteridol) or saline over 4 weeks. Rats were evaluated 6 and 34 weeks after injection with five behavioral tests, and inductively coupled plasma mass spectrometry, transmission electron microscopy, and histopathology were performed on urine, serum, cerebrospinal fluid (CSF), basal ganglia, dentate nucleus, and kidney samples. Dunnett post hoc test and Wilcoxon rank sum test were used to compare differences between treatment groups. Results No evidence of differences in any behavioral test was observed between GBCA-exposed rats and control animals at either 6 or 34 weeks (P = .08 to P = .99). Gadolinium concentrations in both neuroanatomic locations were higher in linear GBCA-exposed rats than macrocyclic GBCA-exposed rats at 6 and 34 weeks (P < .001). Gadolinium clearance over time varied among GBCAs, with gadobutrol having the largest clearance (median: 62% for basal ganglia, 70% for dentate) and gadodiamide having no substantial clearance. At 34 weeks, gadolinium was largely cleared from the CSF and serum of gadodiamide-, gadobenate-, gadoterate-, and gadobutrol-exposed rats, especially for the macrocyclic agents (range: 70%-98% removal for CSF, 34%-94% removal for serum), and was nearly completely removed from urine (range: 96%-99% removal). Transmission electron microscopy was used to detect gadolinium foci in linear GBCA-exposed brain tissue, but no histopathologic differences were observed for any GBCA. Conclusion In this rat model, no clinical evidence of neurotoxicity was observed after exposure to linear and macrocyclic gadolinium-based contrast agents at supradiagnostic doses. © RSNA, 2022 Online supplemental material is available for this article.

Unexpected obesity, rather than tumorigenesis, in a conditional mouse model of mitochondrial complex II deficiency.

Mutations in any of the genes encoding the four subunits of succinate dehydrogenase (SDH), a mitochondrial membrane-bound enzyme complex that is involved in both the tricarboxylic acid cycle and the electron transport chain, can lead to a variety of disorders. Recognized conditions with such mutations include Leigh syndrome and hereditary tumors such as pheochromocytoma and paraganglioma (PPGL), renal cell carcinoma, and gastrointestinal stromal tumor. Tumors appear in SDH mutation carriers with dominant inheritance due to loss of heterozygosity in susceptible cells. Here, we describe a mouse model intended to reproduce hereditary PPGL through Cre-mediated loss of SDHC in cells that express tyrosine hydroxylase (TH), a compartment where PPGL is known to originate. We report that while there is modest expansion of TH+ glomus cells in the carotid body upon SDHC loss, PPGL is not observed in such mice, even in the presence of a conditional dominant negative p53 protein and chronic hypoxia. Instead, we report an unexpected phenotype of nondiabetic obesity beginning at about 20 weeks of age. We hypothesize that this obesity is caused by TH+ cell loss or altered phenotype in key compartments of the central nervous system responsible for regulating feeding behavior, coupled with metabolic changes due to loss of peripheral catecholamine production.

TSPAN5 influences serotonin and kynurenine: pharmacogenomic mechanisms related to alcohol use disorder and acamprosate treatment response.

We previously reported that SNPs near TSPAN5 were associated with plasma serotonin (5-HT) concentrations which were themselves associated with selective serotonin reuptake inhibitor treatment outcomes in patients with major depressive disorder (MDD). TSPAN5 SNPs were also associated with alcohol consumption and alcohol use disorder (AUD) risk. The present study was designed to explore the biological function of TSPAN5 with a focus on 5-HT and kynurenine concentrations in the tryptophan pathway. Ethanol treatment resulted in decreased 5-HT concentrations in human induced pluripotent stem cell (iPSC)-derived neuron culture media, and the downregulation of gene expression of TSPAN5, DDC, MAOA, MAOB, TPH1, and TPH2 in those cells. Strikingly, similar observations were made when the cells were treated with acamprosate-an FDA approved drug for AUD therapy. These results were replicated in iPSC-derived astrocytes. Furthermore, TSPAN5 interacted physically with proteins related to clathrin and other vesicle-related proteins, raising the possibility that TSPAN5 might play a role in vesicular function in addition to regulating expression of genes associated with 5-HT biosynthesis and metabolism. Downregulation of TSPAN5 expression by ethanol or acamprosate treatment was also associated with decreased concentrations of kynurenine, a major metabolite of tryptophan that plays a role in neuroinflammation. Knockdown of TSPAN5 also influenced the expression of genes associated with interferon signaling pathways. Finally, we determined that TSPAN5 SNPs were associated with acamprosate treatment outcomes in AUD patients. In conclusion, TSPAN5 can modulate the concentrations of 5-HT and kynurenine. Our data also highlight a potentially novel pharmacogenomic mechanism related to response to acamprosate.

GRK3 deficiency elicits brain immune activation and psychosis.

The G protein-coupled receptor kinase (GRK) family member protein GRK3 has been linked to the pathophysiology of schizophrenia and bipolar disorder. Expression, as well as protein levels, of GRK3 are reduced in post-mortem prefrontal cortex of schizophrenia subjects. Here, we investigate functional behavior and neurotransmission related to immune activation and psychosis using mice lacking functional Grk3 and utilizing a variety of methods, including behavioral, biochemical, electrophysiological, molecular, and imaging methods. Compared to wildtype controls, the Grk3-/- mice show a number of aberrations linked to psychosis, including elevated brain levels of IL-1ß, increased turnover of kynurenic acid (KYNA), hyper-responsiveness to D-amphetamine, elevated spontaneous firing of midbrain dopamine neurons, and disruption in prepulse inhibition. Analyzing human genetic data, we observe a link between psychotic features in bipolar disorder, decreased GRK expression, and increased concentration of CSF KYNA. Taken together, our data suggest that Grk3-/- mice show face and construct validity relating to the psychosis phenotype with glial activation and would be suitable for translational studies of novel immunomodulatory agents in psychotic disorders.

Regulation of Pv-specific interneurons in the medial prefrontal cortex and reward-seeking behaviors.

The corticostriatal circuitry and its glutamate-γ-aminobuturic acid (GABA) interactions play an essential role in regulating neuronal excitability during reward-seeking behavior. However, the contribution of GABAergic interneurons in the corticostriatal circuitry remains unclear. To investigate the role of GABAergic interneurons, we focused on parvalbumin-expressing fast-spiking interneurons (Pv-FSI) in the corticostriatal circuitry using the designer receptors exclusively activated by designer drugs approach in a Pv-Cre mouse model. We hypothesize that Pv-FSI activation elicits changes in cortical glutamate levels and reward-seeking behaviors. To determine molecular and behavioral effects of Pv-FSI, we performed microdialysis and operant conditioning tasks for sucrose and alcohol rewards. In addition, we also examined how alcohol reward itself affects Pv-FSI functioning. Interestingly, our microdialysis results demonstrate that alcohol exposure inhibits Pv-FSI functioning in the medial prefrontal cortex (mPFC) and this consequently can regulate glutamate levels downstream in the nucleus accumbens. For sucrose reward-seeking behaviors, Pv-FSI activation in the mPFC increases sucrose self-administration whereas it does not promote alcohol seeking. For alcohol rewards, however, Pv-FSI activation in the mPFC results in increased compulsive head entry in operant chambers during devaluation procedures. Overall, our results suggest that not only do Pv-FSI contribute to changes in the cortical microcircuit and reward-seeking behaviors but also that alcohol affects Pv-FSI neurotransmission. Therefore, Pv-FSI has prompted interest in their role in maintaining a balance in neuronal excitation/inhibition and in regulating reward-seeking processes such as compulsivity, all of which are important factors for excessive alcohol seeking.

Indirect Medium Spiny Neurons in the Dorsomedial Striatum Regulate Ethanol-Containing Conditioned Reward Seeking.

Adenosine 2A receptor (A2AR)-containing indirect medium spiny neurons (iMSNs) in the dorsomedial striatum (DMS) contribute to reward-seeking behaviors. However, those roles for ethanol-seeking behaviors remain unknown. To investigate ethanol-seeking behaviors, we used an ethanol-containing reward (10% ethanol and 10% sucrose solution; 10E10S). Upon conditioning with 10E10S, mice that initially only preferred 10% sucrose, not 10E10S, showed a stronger preference for 10E10S. Then, we investigated whether the manipulation of the DMS-external globus pallidus (GPe) iMSNs circuit alters the ethanol-containing reward (10E10S) seeking behaviors using the combination of pharmacologic and optogenetic approaches. DMS A2AR activation dampened operant conditioning-induced ethanol-containing reward, whereas A2AR antagonist abolished the effects of the A2AR agonist and restored ethanol-containing reward-seeking. Moreover, pre-ethanol exposure potentiated the A2AR-dependent reward-seeking. Interestingly, mice exhibiting ethanol-containing reward-seeking showed the reduction of the DMS iMSNs activity, suggesting that disinhibiting iMSNs decreases reward-seeking behaviors. In addition, we found that A2AR activation reversed iMSNs neural activity in the DMS. Similarly, optogenetic stimulation of the DMS-GPe iMSNs reduced ethanol-containing reward-seeking, whereas optogenetic inhibition of the DMS-GPe iMSNs reversed this change. Together, our study demonstrates that DMS A2AR and iMSNs regulate ethanol-containing reward-seeking behaviors.SIGNIFICANCE STATEMENT Our findings highlight the mechanisms of how operant conditioning develops the preference of ethanol-containing conditioned reward. Mice exhibiting ethanol-containing reward-seeking showed a reduction of the indirect medium spiny neuronal activity in the dorsomedial striatum. Pharmacological activation of adenosine A2A receptor (A2AR) or optogenetic activation of indirect medium spiny neurons dampened operant conditioned ethanol-containing reward-seeking, whereas inhibiting this neuronal activity restored ethanol-containing reward-seeking. Furthermore, repeated intermittent ethanol exposure potentiated A2AR-dependent reward-seeking. Therefore, our finding suggests that A2AR-containing indirect medium spiny neuronal activation reduces ethanol-containing reward-seeking, which may provide a potential therapeutic target for alcohol use disorder.

Astrocytic equilibrative nucleoside transporter type 1 upregulations in the dorsomedial and dorsolateral striatum distinctly coordinate goal-directed and habitual ethanol-seeking behaviours in mice.

Two distinct dorsal striatum regions, dorsomedial striatum (DMS) and dorsolateral striatum (DLS), are attributed to conditioned goal-directed and habitual reward-seeking behaviours, respectively. Previously, our study shows that the ethanol-sensitive adenosine transporter, equilibrative nucleoside transporter 1 (ENT1), regulates ethanol-drinking behaviours. Although ENT1 is expressed in both neurons and astrocytes, astrocytic ENT1 is thought to regulate adenosine levels in response to ethanol. However, the role of DMS and DLS astrocytic ENT1 in goal-directed and habitual ethanol-seeking is not well known. Here, we identified whether the upregulation of astrocytic ENT1 in the DMS and DLS differentially regulates operant seeking behaviours towards the 10% sucrose (10S); 10% ethanol and 10% sucrose (10E10S); and 10% ethanol (10E) in mice. Using 4 days of random interval (RI), mice exhibited habitual seeking for 10S, but goal-directed seeking towards 10E10S. Using the same mice conditioned with 10E10S, we examined 10E-seeking behaviour on a fixed ratio (FR) for 6 days and RI for 8 days. On the other hand, during FR and the first 4 days of RI schedules, mice showed goal-directed seeking for 10E, whereas mice exhibited habitual seeking for 10E during the last 4 days of RI schedule. Interestingly, DMS astrocytic ENT1 upregulation promotes shift from habitual to goal-directed reward-seeking behaviours. By contrast, DLS astrocytic ENT1 upregulation showed no effects on behavioural shift. Taken together, our findings demonstrate that DMS astrocytic ENT1 contributes to reward-seeking behaviours.

Type 1 equilibrative nucleoside transporter (ENT1) regulates sex-specific ethanol drinking during disruption of circadian rhythms.

Disruptions in circadian rhythms are risk factors for excessive alcohol drinking. The ethanol-sensitive adenosine equilibrative nucleoside transporter type 1 (ENT1, slc29a1) regulates ethanol-related behaviors, sleep, and entrainment of circadian rhythms. However, the mechanism underlying the increased ethanol consumption in ENT1 knockout (KO) mice in constant light (LL) and whether there are sex differences in ethanol consumption in ENT1 mice are less studied. Here, we investigated the effects of loss of ENT1, LL, and sex on ethanol drinking using two-bottle choice. In addition, we monitored the locomotor activity rhythms. We found that LL increased ethanol drinking and reduced accumbal ENT1 expression and adenosine levels in male but not female mice, compared with control mice. Interestingly, only LL-exposed male, not female, ENT1 KO mice exhibited higher ethanol drinking and a longer circadian period with a higher amplitude compared with wild-type (WT) mice. Furthermore, viral-mediated rescue of ENT1 expression in the NAc of ENT1 KO mice reduced ethanol drinking, demonstrating a possible causal link between ENT1 expression and ethanol drinking in males. Together, our findings indicate that deficiency of ENT1 expression contributes to excessive ethanol drinking in a sex-dependent manner.

Ethanol induces maladaptive impulse control and decreased seeking behaviors in mice.

Waiting impulsivity is a risk factor for many psychiatric disorders including alcohol use disorder (AUD). Highly impulsive individuals are vulnerable to alcohol abuse. However, it is not well understood whether chronic alcohol use increases the propensity for impulsive behavior. Here, we establish a novel experimental paradigm demonstrating that continuous binge-like ethanol exposure progressively leads to maladaptive impulsive behavior. To test waiting impulsivity, we employed the 5-choice serial reaction time task (5-CSRTT) in C57BL/6J male mice. We assessed premature responses in the fixed and variable intertrial interval (ITI) 5-CSRTT sessions. We further characterized our ethanol-induced impulsive mice using Open Field, y-maze, two-bottle choice, and an action-outcome task. Our results indicate that continuous binge-like ethanol exposure significantly increased premature responses when mice were tested in variable ITI sessions even during a prolonged abstinent period. Ethanol-induced impulsive mice exhibited anxiety-like behavior during chronic exposures. This behavior was also observed in a separate cohort that was subjected to 20 days of abstinence. Ethanol-treated mice were less motivated for a sucrose reward compared with air-exposed control mice, while also demonstrating reduced responding during action-outcome testing. Overall, ethanol-treated mice demonstrated increased impulsive behavior, but a reduced motivation for a sucrose reward. Although waiting impulsivity has been hypothesized to be a trait or risk factor for AUD, our findings indicate that maladaptive impulse control can also be potentiated or induced by continuous chronic ethanol exposure in mice.

Proteomic Profile of a Chronic Binge Ethanol Exposure Model.

Chronic binge alcohol drinking is known to increase risky decision through pathological impulsive behaviors. Recently, we established a novel rodent model of ethanol-induced waiting impulsivity using 5-choice serial reaction time task (5-CSRTT) in mice. However, molecular mechanisms underlying the chronic binge ethanol-induced waiting impulsivity is not well characterized. Among brain regions involved in impulsivity, the anterior cingulate cortex (ACC) is a major neural substrate for mediating the 5-CSRTT-based waiting impulsivity. Thus, we sought to determine the ACC proteomic profile using label-free proteomics of mice exhibiting ethanol-induced impulsivity. Ingenuity pathway analysis revealed that impulsivity-related proteins involved in ion channel complexes such as KCNIP3 (potassium voltage-gated channel interacting protein 3) and CACNG2 (calcium voltage-gated channel auxiliary subunit gamma 2) are downregulated in the ACC. We identified significant protein expression changes in the mechanistic target of rapamycin (mTOR) canonical pathway between control and ethanol-induced impulsive mice. Impulsive mice showed over 60% of proteins involved in the mTOR canonical pathway have been altered. This pathway has been previously implicated in the neuroadaptation in drugs of abuse and impulsivity. We found substantial changes in the protein levels involved in neurological disorders such as schizophrenia and Alzheimer's disease. Our findings provide a neuroproteomic profile of ethanol-induced impulsive mice.

Novel Adenosine Analog, N6-(4-Hydroxybenzyl)-Adenosine, Dampens Alcohol Drinking and Seeking Behaviors.

Adenosine signaling is associated with ethanol-related behaviors. We previously found that adenosine A2A receptor (A2AR) activation dampens ethanol drinking behaviors in equilibrative nucleoside transporter 1 (ENT1) knockout mice, and A2AR inhibition augments reward-seeking behavior in wild-type mice. The novel adenosine analog N6-(4-hydroxybenzyl)-adenosine (NHBA), which is isolated from the rhizomes of Gastrodia elata, activates A2AR and inhibits ENT1. Here, we examined the effects of NHBA on ethanol drinking in the two-bottle choice test and operant ethanol seeking behaviors. We selected mice exhibiting high ethanol drinking behavior in the two-bottle choice test. NHBA (0.1 mg/kg, i.p.) reduced ethanol drinking behavior in a limited-access 3-hour drinking session in high-consumption ethanol drinking mice, and NHBA (0.1 mg/kg, i.p.) did not alter locomotor activity in the open-field test. Operant conditioning with 10% ethanol and 10% sucrose (10E10S) reward increased zone entries and time spent in the ethanol zone, while NHBA (0.1 mg/kg, i.p.) dampened ethanol zone preference in the Y-maze. Furthermore, NHBA (0.1 mg/kg, i.p.) devalued 10E10S and 10% ethanol (10E) reward after operant conditioning with 10E10S and 10E. Taken together, NHBA through A2AR activation and ENT1 modulation may dampen ethanol drinking and seeking behaviors, suggesting that NHBA is a potential therapeutic agent for treating alcohol use disorder. SIGNIFICANCE STATEMENT: Our work highlights that A2AR activation and ENT1 inhibition by a novel adenosine analog isolated from Gastrodia elata, N6-(4-hydroxybenzyl)-adenosine, decreases ethanol drinking and seeking behaviors. We suggest that NHBA is a potential therapeutic agent to treat alcohol use disorder.

Chronic Ethanol Exposure Disrupts Lactate and Glucose Homeostasis and Induces Dysfunction of the Astrocyte-Neuron Lactate Shuttle in the Brain.

BACKGROUND: Impairment of monocarboxylate transporter (MCT)-dependent astrocyte-neuron lactate transfer disrupts long-term memory and erases drug-associated memories in mice. However, few studies have examined how drugs of abuse alter astrocyte-neuron lactate transfer in neurocircuits related to addiction. This is particularly pertinent for ethanol (EtOH), which has been demonstrated to impair central nervious system (CNS) glucose uptake and significantly alter peripheral levels of glucose, lactate, acetate, and ketones. METHODS: We subjected C57BL/6J mice to a chronic intermittent EtOH (CIE) exposure paradigm to investigate how chronic EtOH exposure alters the concentration of glucose and lactate within the serum and CNS during withdrawal. Next, we determine how chronic injections of lactate (1 g/kg, twice daily for 2 weeks) influence central and peripheral glucose and lactate concentrations. Finally, we determine how CIE and chronic lactate injection affect astrocyte-neuron lactate transfer by analyzing the expression of MCTs. RESULTS: Our results show that CIE induces lasting changes in CNS glucose and lactate concentrations, accompanied by increased expression of MCTs. Interestingly, although chronic lactate injection mimics the effect of EtOH on CNS metabolites, chronic lactate injection is not associated with increased expression of MCTs. CONCLUSION: CIE increases CNS concentrations of glucose and lactate and augments the expression of MCTs. Although we found that chronic lactate injection mimics EtOH-induced increases in CNS lactate and glucose, lactate failed to alter the expression of MCTs. This suggests that although lactate may influence the homeostasis of bioenergetic molecules in the CNS, EtOH-associated increases in lactate are not responsible for increased MCT expression.

Pharmacoproteomics Profile in Response to Acamprosate Treatment of an Alcoholism Animal Model.

Acamprosate is an FDA-approved medication for the treatment of alcoholism that is unfortunately only effective in certain patients. Although acamprosate is known to stabilize the hyper-glutamatergic state in alcoholism, pharmacological mechanisms of action in brain tissue remains unknown. To investigate the mechanism of acamprosate efficacy, the authors employ a pharmacoproteomics approach using an animal model of alcoholism, type 1 equilibrative nucleoside transporter (ENT1) null mice. The results demonstrate that acamprosate treatment significantly decreased both ethanol drinking and preference in ENT1 null mice compared to that of wild-type mice. Then, to elucidate acamprosate efficacy mechanism in ENT1 null mice, the authors utilize label-free quantification proteomics comparing both genotype and acamprosate treatment effects in the nucleus accumbens (NAc). A total of 1040 protein expression changes are identified in the NAc among 3634 total proteins detected. The proteomics and Western blot result demonstrate that acamprosate treatment decreased EAAT expression implicating stabilization of the hyper-glutamatergic condition in ENT1 null mice. Pathway analysis suggests that acamprosate treatment in ENT1 null mice seems to rescue glutamate toxicity through restoring of RTN4 and NF-κB medicated neuroimmune signaling compared to wild-type mice. Overall, pharmacoproteomics approaches suggest that neuroimmune restoration is a potential efficacy mechanism in the acamprosate treatment of certain sub-populations of alcohol dependent subjects.

Label-Free Neuroproteomics of the Hippocampal-Accumbal Circuit Reveals Deficits in Neurotransmitter and Neuropeptide Signaling in Mice Lacking Ethanol-Sensitive Adenosine Transporter.

The neural circuit of the dorsal hippocampus (dHip) and nucleus accumbens (NAc) contributes to cue-induced learning and addictive behaviors, as demonstrated by the escalation of ethanol-seeking behaviors observed following deletion of the adenosine equilibrative nucleoside transporter 1 (ENT1-/-) in mice. Here we perform quantitative LC-MS/MS neuroproteomics in the dHip and NAc of ENT1-/- mice. Using Ingenuity Pathway Analysis, we identified proteins associated with increased long-term potentiation, ARP2/3-mediated actin cytoskeleton signaling and protein expression patterns suggesting deficits in glutamate degradation, GABAergic signaling, as well as significant changes in bioenergetics and energy homeostasis (oxidative phosphorylation, TCA cycle, and glycolysis). These pathways are consistent with previously reported behavioral and biochemical phenotypes that typify mice lacking ENT1. Moreover, we validated decreased expression of the SNARE complex protein VAMP1 (synaptobrevin-1) in the dHip as well as decreased expression of pro-dynorphin (PDYN), neuroendocrine convertase (PCSK1), and Leu-Enkephalin (dynorphin-A) in the NAc. Taken together, our proteomic approach provides novel pathways indicating that ENT1-regulated signaling is essential for neurotransmitter release and neuropeptide processing, both of which underlie learning and reward-seeking behaviors.

Combination Varenicline and Lorcaserin for Tobacco Dependence Treatment and Weight Gain Prevention in Overweight and Obese Smokers: A Pilot Study.

INTRODUCTION: Post-cessation weight gain (PCWG) is a major barrier to maintaining abstinence, especially in weight-concerned smokers. Varenicline is the most effective medication for smoking cessation but has minimal impact on PCWG. Lorcaserin is an FDA-approved medication for weight management in overweight or obese patients which also provides a noticeable benefit in treating drug dependence. We hypothesized that combining varenicline with lorcaserin may help prevent PCWG. We conducted an open-label, single arm, Phase II clinical pilot study to obtain preliminary data on the safety and effectiveness of combination varenicline and lorcaserin in preventing PCWG in overweight and obese smokers. METHODS: Twenty overweight or obese (body mass index 27-40 kg/m2) cigarette smokers were enrolled. The primary outcomes were weight and waist circumference (WC) changes at 12 and 26 weeks in smokers meeting criteria for prolonged smoking abstinence. All participants received open-label varenicline (1 mg twice a day) and lorcaserin (10 mg twice a day) for 12 weeks with follow-up at 26 weeks. RESULTS: Ten subjects met criteria for prolonged smoking abstinence at 12 weeks (50%) and 6 at 26 weeks (30%). Among those achieving prolonged smoking abstinence at 12 weeks, WC was +0.2 ± 6.0 cm (90% CI; -2.9, +3.4) and weight gain was +1.1 ± 3.9 kg (90% CI; -0.9, +3.1). CONCLUSIONS: Weight gain and WC increases following prolonged smoking abstinence may be reduced among overweight and obese smokers using combination varenicline and lorcaserin. This combinatory treatment warrants further research in the obese and weight-concerned smoking population. IMPLICATIONS: This is the first published prospective pilot study to evaluate lorcaserin for use in reducing PCWG in overweight and obese smokers. When combined with varenicline, lorcaserin minimized PCWG and increases in WC. In addition to the benefit on PCWG reduction, lorcaserin may be a potential new pharmacological treatment for smoking cessation and warrants further larger studies.

Modulatory effects of perforin gene dosage on pathogen-associated blood-brain barrier (BBB) disruption.

BACKGROUND: CD8 T cell-mediated blood-brain barrier (BBB) disruption is dependent on the effector molecule perforin. Human perforin has extensive single nucleotide variants (SNVs), the significance of which is not fully understood. These SNVs can result in reduced, but not ablated, perforin activity or expression. However, complete loss of perforin expression or activity results in the lethal disease familial hemophagocytic lymphohistiocytosis type 2 (FHL 2). In this study, we address the hypothesis that a single perforin allele can alter the severity of BBB disruption in vivo using a well-established model of CNS vascular permeability in C57Bl/6 mice. The results of this study provide insight into the significance of perforin SNVs in the human population. METHODS: We isolated the effect a single perforin allele has on CNS vascular permeability through the use of perforin-heterozygous (perforin+/-) C57BL/6 mice in the peptide-induced fatal syndrome (PIFS) model of immune-mediated BBB disruption. Seven days following Theiler's murine encephalomyelitis virus (TMEV) CNS infection, neuroinflammation and TMEV viral control were assessed through flow cytometric analysis and quantitative real-time PCR of the viral genome, respectively. Following immune-mediated BBB disruption, gadolinium-enhanced T1-weighted MRI, with 3D volumetric analysis, and confocal microscopy were used to define CNS vascular permeability. Finally, the open field behavior test was used to assess locomotor activity of mice following immune-mediated BBB disruption. RESULTS: Perforin-null mice had negligible CNS vascular permeability. Perforin-WT mice have extensive CNS vascular permeability. Interestingly, perforin-heterozygous mice had an intermediate level of CNS vascular permeability as measured by both gadolinium-enhanced T1-weighted MRI and fibrinogen leakage in the brain parenchyma. Differences in BBB disruption were not a result of increased CNS immune infiltrate. Additionally, TMEV was controlled in a perforin dose-dependent manner. Furthermore, a single perforin allele is sufficient to induce locomotor deficit during immune-mediated BBB disruption. CONCLUSIONS: Perforin modulates BBB disruption in a dose-dependent manner. This study demonstrates a potentially advantageous role for decreased perforin expression in reducing BBB disruption. This study also provides insight into the effect SNVs in a single perforin allele could have on functional deficit in neurological disease.

Anterior Cingulate Glutamate Is Reduced by Acamprosate Treatment in Patients With Alcohol Dependence.

Although the precise drug mechanism of action of acamprosate remains unclear, its antidipsotropic effect is mediated in part through glutamatergic neurotransmission. We evaluated the effect of 4 weeks of acamprosate treatment in a cohort of 13 subjects with alcohol dependence (confirmed by a structured interview, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision) on proton magnetic resonance spectroscopy glutamate levels in the midline anterior cingulate cortex (MACC). We compared levels of metabolites with a group of 16 healthy controls. The Pennsylvania Alcohol Craving Scale was used to assess craving intensity. At baseline, before treatment, the mean cerebrospinal fluid-corrected MACC glutamate (Glu) level was significantly elevated in subjects with alcohol dependence compared with controls (P = 0.004). Four weeks of acamprosate treatment reduced glutamate levels (P = 0.025), an effect that was not observed in subjects who did not take acamprosate. At baseline, there was a significant positive correlation between cravings, measured by the Pennsylvania Alcohol Craving Scale, and MACC (Glu) levels (P = 0.019). Overall, these data would suggest a normalizing effect of acamprosate on a hyperglutamatergic state observed in recently withdrawn patients with alcohol dependence and a positive association between MACC glutamate levels and craving intensity in early abstinence. Further research is needed to evaluate the use of these findings for clinical practice, including monitoring of craving intensity and individualized selection of treatment with antidipsotropic medications in subjects with alcohol dependence.

Combined Effects of Acamprosate and Escitalopram on Ethanol Consumption in Mice.

BACKGROUND: Major depression is one of the most prevalent psychiatry comorbidities of alcohol use disorders (AUD). As negative emotions can trigger craving and increase the risk of relapse, treatments that target both conditions simultaneously may augment treatment success. Previous studies showed a potential synergistic effect of Food and Drug Administration approved medication for AUD acamprosate and the antidepressant escitalopram. In this study, we investigated the effects of combining acamprosate and escitalopram on ethanol (EtOH) consumption in stress-induced depressed mice. METHODS: Forty singly housed C57BL/6J male mice were subjected to chronic unpredictable stress. In parallel, 40 group-housed male mice were subjected to normal husbandry. After 3 weeks, depressive- and anxiety-like behaviors and EtOH consumption were assessed. For the next 7 days, mice were injected with saline, acamprosate (200 mg/kg; twice/d), escitalopram (5 mg/kg; twice/d), or their combination (n = 9 to 11/drug group/stress group). Two-bottle choice limited-access drinking of 15% EtOH and tap water was performed 3 hours into dark phase immediately after the daily dark phase injection. EtOH drinking was monitored for another 7 days without drug administration. RESULTS: Mice subjected to the chronic unpredictable stress paradigm for 3 weeks showed apparent depression- and anxiety-like behaviors compared to their nonstressed counterparts including longer immobility time in the forced swim test and lower sucrose preference. Stressed mice also displayed higher EtOH consumption and preference in a 2-bottle choice drinking test. During the drug administration period, the escitalopram-only and combined drug groups showed significant reduction in EtOH consumption in nonstressed mice, while only the combined drug group showed significantly reduced consumption in stressed mice. However, such reduction did not persist into the postdrug administration period. CONCLUSIONS: The combination of acamprosate and escitalopram suppressed EtOH intake in both nonstressed and stressed mice; hence, this combination is potentially helpful for AUD individuals with or without comorbid depression to reduce alcohol use.