| 1. |
- Sreedharan, Smitha, et al.
(author)
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GPR162 is expressed in the hypothalamus and is involved in food intake related behaviour
- 2011
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Other publication (other academic/artistic)abstract
- The Rhodopsin family of G protein-coupled receptors (GPCRs) includes about 270 non-olfactory receptors and is the largest family of GPCRs. About sixty non-olfactory Rhodopsin GPCRs are still orphans without known ligands, and fairly little is known about their functions. In this study, we present molecular, neuroanatomical, genetic and behavioral data implicating a Rhodopsin family protein, GPR162, in the regulation of food intake-related behaviour and glucose homeostasis. The real-time PCR data show that GPR162 is predominantly expressed in the CNS. The in situ hybridization results confirmed significant expression of GPR162 in several hypothalamic sites, amygdala, substantia nigra and ventral tegmental area, among others regions. In line with the distribution of the GPR162 mRNA in the feeding circuitry, antisense oligo knockdown of GPR162 caused a significant reduction in food intake but no effect was observed towards reduction in body weight in rats. Our human genetics studies suggest that genetic variants of GPR162 affect glucose homeostasis. In conclusion, this study provides evidence linking the orphan GPR162 gene with the regulation of food intake-related behaviour.
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| 2. |
- Caruso, Vanni, et al.
(author)
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mRNA GPR162 changes are associated with decreased food intake in rat, and its human genetic variants with impairments in glucose homeostasis in two Swedish cohorts
- 2016
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In: Gene. - : Elsevier BV. - 0378-1119 .- 1879-0038. ; 581:2, s. 139-145
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Journal article (peer-reviewed)abstract
- G protein-coupled receptors (GPCRs) are a class of integral membrane proteins mediating intercellular interactions of fundamental physiological importance for survival including regulation of food intake, blood pressure, and hormonal sensing signaling, among other roles. Homeostatic alterations in the physiological status of GPCRs are often associated with underlying causes of disease, and to date, several orphan GPCRs are still uncharacterized. Findings from our previous study demonstrate that the Rhodopsin family protein GPR162 is widely expressed in GABAergic as well as other neurons within the mouse hippocampus, whereas extensive expression is observed in hypothalamus, amygdala, and ventral tegmental area, regions strictly interconnected and involved in the regulation of energy homeostasis and hedonic feeding. In this study, we provide a further anatomical characterization of GPR162 in mouse brain via in situ hybridization as well as detailed mRNA expression in a panel of rat tissues complementing a specie-specific mapping of the receptor. We also provide an attempt to demonstrate a functional implication of GPR162 in food intake-related behavior via antisense knockdown studies. Furthermore, we performed human genetic studies in which for the first time, variants of the GPR162 gene were associated with impairments in glucose homeostasis.
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| 3. |
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| 4. |
- Johnstone, Andrea L., et al.
(author)
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Dysregulation of the histone demethylase KDM6B in alcohol dependence is associated with epigenetic regulation of inflammatory signaling pathways
- 2021
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In: Addiction Biology. - : WILEY. - 1355-6215 .- 1369-1600. ; 26:1
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Journal article (peer-reviewed)abstract
- Epigenetic enzymes oversee long-term changes in gene expression by integrating genetic and environmental cues. While there are hundreds of enzymes that control histone and DNA modifications, their potential roles in substance abuse and alcohol dependence remain underexplored. A few recent studies have suggested that epigenetic processes could underlie transcriptomic and behavioral hallmarks of alcohol addiction. In the present study, we sought to identify epigenetic enzymes in the brain that are dysregulated during protracted abstinence as a consequence of chronic and intermittent alcohol exposure. Through quantitative mRNA expression analysis of over 100 epigenetic enzymes, we identified 11 that are significantly altered in alcohol-dependent rats compared with controls. Follow-up studies of one of these enzymes, the histone demethylase KDM6B, showed that this enzyme exhibits region-specific dysregulation in the prefrontal cortex and nucleus accumbens of alcohol-dependent rats. KDM6B was also upregulated in the human alcoholic brain. Upregulation of KDM6B protein in alcohol-dependent rats was accompanied by a decrease of trimethylation levels at histone H3, lysine 27 (H3K27me3), consistent with the known demethylase specificity of KDM6B. Subsequent epigenetic (chromatin immunoprecipitation [ChIP]-sequencing) analysis showed that alcohol-induced changes in H3K27me3 were significantly enriched at genes in the IL-6 signaling pathway, consistent with the well-characterized role of KDM6B in modulation of inflammatory responses. Knockdown of KDM6B in cultured microglial cells diminished IL-6 induction in response to an inflammatory stimulus. Our findings implicate a novel KDM6B-mediated epigenetic signaling pathway integrated with inflammatory signaling pathways that are known to underlie the development of alcohol addiction.
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| 5. |
- Nilsson, Jan, et al.
(author)
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Långtidskomplikationer – postakut covid-19-syndrom
- 2021
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In: Vad kan vi lära av pandemin? : Kunskapsöversikt från Kungl. Vetenskapsakademiens expertgrupp om covid-19. - Kunskapsöversikt från Kungl. Vetenskapsakademiens expertgrupp om covid-19.. ; , s. 56-64
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Book chapter (other academic/artistic)
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| 6. |
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| 7. |
- Ramchandani, V A, et al.
(author)
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A genetic determinant of the striatal dopamine response to alcohol in men
- 2011
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In: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 16:8, s. 809-817
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Journal article (peer-reviewed)abstract
- Excessive alcohol use, a major cause of morbidity and mortality, is less well understood than other addictive disorders. Dopamine release in ventral striatum is a common element of drug reward, but alcohol has an unusually complex pharmacology, and humans vary greatly in their alcohol responses. This variation is related to genetic susceptibility for alcoholism, which contributes more than half of alcoholism risk. Here, we report that a functional OPRM1 A118G polymorphism is a major determinant of striatal dopamine responses to alcohol. Social drinkers recruited based on OPRM1 genotype were challenged in separate sessions with alcohol and placebo under pharmacokinetically controlled conditions, and examined for striatal dopamine release using positron emission tomography and [(11)C]-raclopride displacement. A striatal dopamine response to alcohol was restricted to carriers of the minor 118G allele. To directly establish the causal role of OPRM1 A118G variation, we generated two humanized mouse lines, carrying the respective human sequence variant. Brain microdialysis showed a fourfold greater peak dopamine response to an alcohol challenge in h/mOPRM1-118GG than in h/mOPRM1-118AA mice. OPRM1 A118G variation is a genetic determinant of dopamine responses to alcohol, a mechanism by which it likely modulates alcohol reward.
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| 8. |
- Robinson, J. E., et al.
(author)
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Potentiation of brain stimulation reward by morphine : effects of neurokinin-1 receptor antagonism
- 2012
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In: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 220:1, s. 215-224
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Journal article (peer-reviewed)abstract
- RATIONALE: The abuse potential of opioids may be due to their reinforcing and rewarding effects, which may be attenuated by neurokinin-1 receptor (NK1R) antagonists.OBJECTIVE: This study was conducted to measure the effects of opioid and NK1R blockade on the potentiation of brain stimulation reward (BSR) by morphine using the intracranial self-stimulation method.METHODS: Adult male C57BL/6J mice (n = 15) were implanted with unipolar stimulating electrodes in the lateral hypothalamus and trained to respond for varying frequencies of rewarding electrical stimulation. The BSR threshold (θ(0)) and maximum response rate (MAX) were determined before and after intraperitoneal administration of saline, morphine (1.0-17.0 mg/kg), or the NK1R antagonists L-733,060 (1.0-17.0 mg/kg) and L-703,606 (1.0-17.0 mg/kg). In morphine antagonism experiments, naltrexone (0.1-1.0 mg/kg) or 10.0 mg/kg L-733,060 or L-703,606 was administered 15 min before morphine (1.0-10.0 mg/kg) or saline.RESULTS: Morphine dose-dependently decreased θ(0) (maximum effect = 62% of baseline) and altered MAX when compared to saline. L-703,606 and L-733,060 altered θ(0); 10.0 mg/kg L-733,060 and L-703,606, which did not affect θ(0) or MAX, attenuated the effects of 3.0 and 10.0 mg/kg morphine, and 1.0 and 0.3 mg/kg naltrexone blocked the effects of 10.0 mg/kg morphine. Naltrexone given before saline did not affect θ(0) or MAX.CONCLUSIONS: The decrease in θ(0) by morphine reflects its rewarding effects, which were attenuated by NK1R and opioid receptor blockade. These results demonstrate the importance of substance P signaling during limbic reward system activation by opioids.
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| 9. |
- Sreedharan, Smitha, et al.
(author)
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The G protein coupled receptor Gpr153 shares common evolutionary origin with Gpr162 and is highly expressed in central regions including the thalamus, cerebellum and the arcuate nucleus
- 2011
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In: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 278:24, s. 4881-4894
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Journal article (peer-reviewed)abstract
- The Rhodopsin family of G protein-coupled receptors (GPCRs) includes the phylogenetic α-group consisting of about 100 human members. The α-group is the only group of GPCRs that has many receptors for biogenic amines which are major drug targets. Several members of this group are orphan receptors and their functions are elusive. In this study we present a detailed phylogenetic and anatomical characterization of the Gpr153 receptor and also attempted to study its functional role. We identified the homologue of GPR153 in the elephant shark genome and phylogenetic and synteny analyses revealed that Gpr162 originated from Gpr153, through a duplication event before the radiation of the amphibian lineage. Quantitative real time PCR study reveals wide spread expression of GPR153 in the CNS and all the peripheral tissues investigated. Detailed in situ hybridization on mouse brain showed specifically high expression in the thalamus, cerebellum and the arcuate nucleus. The antisense oligodeoxynucleotide knockdown of GPR153 caused a slight reduction in food intake and the elevated plus maze test showed significant reduction in the percentage of time spent in the centre square, which points towards a probable role in decision making. This report provides the first detailed characterization of the evolution, expression and as well as primary functional properties of the GPR153 gene.
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