| 1. |
- Sarkisyan, Daniil, et al.
(författare)
-
Downregulation of the endogenous opioid peptides in the dorsal striatum of human alcoholics
- 2015
-
Ingår i: Frontiers in Cellular Neuroscience. - : Frontiers Media SA. - 1662-5102. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- The endogenous opioid peptides dynorphins and enkephalins may be involved in brain-area specific synaptic adaptations relevant for different stages of an addiction cycle. We compared the levels of prodynorphin (PDYN) and proenkephalin (PENK) mRNAs (by qRT-PCR), and dynorphins and enkephalins (by radioimmunoassay) in the caudate nucleus and putamen between alcoholics and control subjects. We also evaluated whether PDYN promoter variant rs1997794 associated with alcoholism affects PDYN expression. Postmortem specimens obtained from 24 alcoholics and 26 controls were included in final statistical analysis. PDYN mRNA and Met-enkephalin-Arg-Phe, a marker of PENK were downregulated in the caudate of alcoholics, while PDYN mRNA and Leu-enkephalin-Arg, a marker of PDYN were decreased in the putamen of alcoholics carrying high risk rs1997794 C allele. Downregulation of opioid peptides in the dorsal striatum may contribute to development of alcoholism including changes in goal directed behavior and formation of a compulsive habit in alcoholics.
|
|
| 2. |
- Eriksson, Anders, et al.
(författare)
-
Implication of coronin 7 in body weight regulation in humans, mice and flies
- 2015
-
Ingår i: BMC Neuroscience. - : Springer Science and Business Media LLC. - 1471-2202. ; 16
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Obesity is a growing global concern with strong associations with cardiovascular disease, cancer and type-2 diabetes. Although various genome-wide association studies have identified more than 40 genes associated with obesity, these genes cannot fully explain the heritability of obesity, suggesting there may be other contributing factors, including epigenetic effects. Results: We performed genome wide DNA methylation profiling comparing normal-weight and obese 9-13 year old children to investigate possible epigenetic changes correlated with obesity. Of note, obese children had significantly lower methylation levels at a CpG site located near coronin 7 (CORO7), which encodes a tryptophan-aspartic acid dipeptide (WD)-repeat containing protein most likely involved in Golgi complex morphology and function. Anatomical profiling of coronin 7 (Coro7) mRNA expression in mice revealed that it is highly expressed in appetite and energy balance regulating regions, including the hypothalamus, striatum and locus coeruleus, the main noradrenergic brain site. Interestingly, we found that food deprivation in mice downregulates hypothalamic Coro7 mRNA levels, and injecting ethanol, an appetite stimulant, increased the number of Coro7 expressing cells in the locus coeruleus. Finally, by employing the genetically-tractable Drosophila melanogaster model we were able to demonstrate an evolutionarily conserved metabolic function for the CORO7 homologue pod1. Knocking down the pod1 in the Drosophila adult nervous system increased their resistance to starvation. Furthermore, feeding flies a high-calorie diet significantly increased pod1 expression. Conclusion: We conclude that coronin 7 is involved in the regulation of energy homeostasis and this role stems, to some degree, from the effect on feeding for calories and reward.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Sommansson, Anna, et al.
(författare)
-
Long-term oral melatonin administration reduces ethanol-induced increases in duodenal mucosal permeability and motility in rats
- 2014
-
Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 212:2, s. 152-165
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: Increased intestinal epithelial permeability is associated with intestinal inflammation and dysfunction. The aim of the present study was to investigate the role of long-term oral melatonin administration on ethanol-induced increases in duodenal mucosal permeability and hypermotility. Methods: Male Sprague-Dawley rats were administered melatonin in their tap water (0.1 mg mL(-1) or 0.5 mg mL(-1)) for 2 or 4 weeks. After the treatment period, the rats were anaesthetized with Inactin (R), and a 30-mm duodenal segment was perfused in situ. The effects on duodenal mucosal paracellular permeability, bicarbonate secretion, fluid flux and motor activity were studied. The expression levels of the tight junction components, zona occludens (ZO)-1, ZO-2, and ZO-3, claudin-2, claudin-3, claudin-4, occludin, and myosin light chain kinase and of the melatonin receptors MT1 and MT2 were assessed using qRT-PCR. Results: Melatonin administration for 2 weeks significantly reduced the basal paracellular permeability, an effect that was absent after 4 weeks. Perfusing the duodenal segment with 15% ethanol induced marked increases in duodenal paracellular permeability, bicarbonate secretion and motor activity. Melatonin for 2 weeks dose-dependently reduced ethanol-induced increases in permeability and motor activity. Four weeks of melatonin administration reduced the ethanol-induced increases in duodenal motility and bicarbonate secretion but had no effect on the increases in permeability. Two weeks of melatonin administration upregulated the expression of MT1 and MT2, although both were downregulated after 4 weeks. Melatonin downregulated the expression of ZO-3 and upregulated the expression of claudin-2, even as all other mRNA-levels investigated were unaffected. Conclusion: Although further studies are needed, our data demonstrate that melatonin administration markedly improves duodenal barrier functions, suggesting its utility in clinical applications when intestinal barrier functions are compromised.
|
|
| 8. |
- Taqi, Malik Mumtaz, et al.
(författare)
-
Conformation Effects of CpG Methylation on Single-Stranded DNA Oligonucleotides : Analysis of the Opioid Peptide Dynorphin-Coding Sequences
- 2012
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:6, s. e39605-
-
Tidskriftsartikel (refereegranskat)abstract
- Single-stranded DNA (ssDNA) is characterized by high conformational flexibility that allows these molecules to adopt a variety of conformations. Here we used native polyacrylamide gel electrophoresis (PAGE), circular dichroism (CD) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy to show that cytosine methylation at CpG sites affects the conformational flexibility of short ssDNA molecules. The CpG containing 37-nucleotide PDYN (prodynorphin) fragments were used as model molecules. The presence of secondary DNA structures was evident from differences in oligonucleotide mobilities on PAGE, from CD spectra, and from formation of A-T, G-C, and non-canonical G-T base pairs observed by NMR spectroscopy. The oligonucleotides displayed secondary structures at 4 degrees C, and some also at 37 degrees C. Methylation at CpG sites prompted sequence-dependent formation of novel conformations, or shifted the equilibrium between different existing ssDNA conformations. The effects of methylation on gel mobility and base pairing were comparable in strength to the effects induced by point mutations in the DNA sequences. The conformational effects of methylation may be relevant for epigenetic regulatory events in a chromatin context, including DNA-protein or DNA-DNA recognition in the course of gene transcription, and DNA replication and recombination when double-stranded DNA is unwinded to ssDNA.
|
|
| 9. |
- Williams, Michael, et al.
(författare)
-
The obesity-linked Nudt3 Drosophila homolog Aps is associated with insulin signalling
- 2015
-
Ingår i: Molecular Endocrinology. - 0888-8809 .- 1944-9917. ; 29:9, s. 1303-1319
-
Tidskriftsartikel (refereegranskat)abstract
- Several genome-wide association studies have linked the Nudix hydrolase family member nucleoside diphosphate-linked moiety X motif 3 (NUDT3) to obesity. However, the manner of NUDT3 involvement in obesity is unknown, and NUDT3 expression, regulation, and signaling in the central nervous system has not been studied. We performed an extensive expression analysis in mice, as well as knocked down the Drosophila NUDT3 homolog Aps in the nervous system, to determine its effect on metabolism. Detailed in situ hybridization studies in the mouse brain revealed abundant Nudt3 mRNA and protein expression throughout the brain, including reward- and feeding-related regions of the hypothalamus and amygdala, whereas Nudt3 mRNA expression was significantly up-regulated in the hypothalamus and brainstem of food-deprived mice. Knocking down Aps in the Drosophila central nervous system, or a subset of median neurosecretory cells, known as the insulin-producing cells (IPCs), induces hyperinsulinemia-like phenotypes, including a decrease in circulating trehalose levels as well as significantly decreasing all carbohydrate levels under starvation conditions. Moreover, lowering Aps IPC expression leads to a decreased ability to recruit these lipids during starvation. Also, loss of neuronal Aps expression caused a starvation susceptibility phenotype while inducing hyperphagia. Finally, the loss of IPC Aps lowered the expression of Akh, llp6, and llp3, genes known to be inhibited by insulin signaling. These results point toward a role for this gene in the regulation of insulin signaling, which could explain the robust association with obesity in humans.
|
|
