| 1. |
- Björkqvist, Maria, et al.
(författare)
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Somatostatin, misoprostol and galanin inhibit gastrin- and PACAP-stimulated secretion of histamine and pancreastatin from ECL cells by blocking specific Ca(2+) channels.
- 2005
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 130:1-2, s. 81-90
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Tidskriftsartikel (refereegranskat)abstract
- The oxyntic mucosa is rich in ECL cells. They secrete histamine and chromogranin A-derived peptides, such as pancreastatin, in response to gastrin and pituitary adenylate cyclase-activating peptide (PACAP). Secretion is initiated by Ca2+ entry. While gastrin stimulates secretion by opening L-type and N-type Ca2+ channels, PACAP stimulates secretion by activating L-type and receptor-operated Ca2+ channels. Somatostatin, galanin and prostaglandin E2 (PGE2) inhibit gastrin- and PACAP-stimulated secretion from the ECL cells. In the present study, somatostatin and the PGE2 congener misoprostol inhibited gastrin- and PACAP-stimulated secretion 100%, while galanin inhibited at most 60–65%. Bay K 8644, a specific activator of L-type Ca2+ channels, stimulated ECL-cell secretion, an effect that was inhibited equally effectively by somatostatin, misoprostol and galanin (75–80% inhibition). Pretreatment with pertussis toxin, that inactivates inhibitory G-proteins, prevented all three agents from inhibiting stimulated secretion (regardless of the stimulus). Pretreatment with nifedipine (10 μM), an L-type Ca2+ channel blocker, reduced PACAP-evoked pancreastatin secretion by 50–60%, gastrin-evoked secretion by not, vert, similar 80% and abolished the response to Bay K 8644. The nifedipine-resistant response to PACAP was abolished by somatostatin and misoprostol but not by galanin. Gastrin and PACAP raised the intracellular Ca2+ concentration in a biphasic manner, believed to reflect mobilization of internal Ca2+ followed by Ca2+ entry. Somatostatin and misoprostol blocked Ca2+ entry (and histamine and pancreastatin secretion) but not mobilization of internal Ca2+. The present observations on isolated ECL cells suggest that Ca2+ entry rather than mobilization of internal Ca2+ triggers exocytosis, that gastrin and PACAP activate different (but over-lapping) Ca2+ channels, that somatostatin, misoprostol and galanin interact with inhibitory G-proteins to block Ca2+ entry via L-type Ca2+ channels, and that somatostatin and misoprostol (but not galanin) in addition block N-type and/or receptor-operated Ca2+ channels.
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| 2. |
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| 3. |
- Duarte, Ana I., et al.
(författare)
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Dual Therapy with Liraglutide and Ghrelin Promotes Brain and Peripheral Energy Metabolism in the R6/2 Mouse Model of Huntington's Disease
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Neuronal loss alongside altered energy metabolism, are key features of Huntington's disease (HD) pathology. The orexigenic gut-peptide hormone ghrelin is known to stimulate appetite and affect whole body energy metabolism. Liraglutide is an efficient anti-type 2 diabetes incretin drug, with neuroprotective effects alongside anorectic properties. Combining liraglutide with the orexigenic peptide ghrelin may potentially promote brain/cognitive function in HD. The R6/2 mouse model of HD exhibits progressive central pathology, weight loss, deranged glucose metabolism, skeletal muscle atrophy and altered body composition. In this study, we targeted energy metabolism in R6/2 mice using a co-administration of liraglutide and ghrelin. We investigated their effect on brain cortical hormone-mediated intracellular signalling pathways, metabolic and apoptotic markers, and the impact on motor function in HD. We here demonstrate that liraglutide, alone or together with ghrelin (subcutaneous daily injections of 150 μg/kg (ghrelin) and 0.2 mg/kg (liraglutide), for 2 weeks), normalized glucose homeostatic features in the R6/2 mouse, without substantially affecting body weight or body composition. Liraglutide alone decreased brain cortical active GLP-1 and IGF-1 levels in R6/2 mice, alongside higher ADP levels. Liraglutide plus ghrelin decreased brain insulin, lactate, AMP and cholesterol levels in R6/2 mice. Taken together, our findings encourage further studies targeting energy metabolism in HD.
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| 6. |
- Reynolds, Regina Hertfelder, et al.
(författare)
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Perturbations in the p53/miR-34a/SIRT1 pathway in the R6/2 Huntington's disease model
- 2018
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Ingår i: Molecular and Cellular Neuroscience. - : Elsevier BV. - 1044-7431. ; 88, s. 118-129
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Tidskriftsartikel (refereegranskat)abstract
- The three factors, p53, the microRNA-34 family and Sirtuin 1 (SIRT1), interact in a positive feedback loop involved in cell cycle progression, cellular senescence and apoptosis. Each factor in this triad has roles in metabolic regulation, maintenance of mitochondrial function, and regulation of brain-derived neurotrophic factor (BDNF). Thus, this regulatory network holds potential importance for the pathophysiology of Huntington's disease (HD), an inherited neurodegenerative disorder in which both mitochondrial dysfunction and impaired neurotrophic signalling are observed. We investigated expression of the three members of this regulatory triad in the R6/2 HD mouse model. Compared to wild-type littermates, we found decreased levels of miR-34a-5p, increased SIRT1 mRNA and protein levels, and increased levels of p53 protein in brain tissue from R6/2 mice. The upregulation of SIRT1 did not appear to lead to an increased activity of the enzyme, as based on measures of p53 acetylation. In other words, the observed changes did not reflect the known interactions between these factors, indicating a general perturbation of the p53, miR-34a and SIRT1 pathway in HD. This is the first study investigating the entire triad during disease progression in an HD model. Given the importance of these three factors alone and within the triad, our results indicate that outside factors are regulating – or dysregulating – this pathway in HD.
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| 7. |
- Allbrand, Marianne, 1958-, et al.
(författare)
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Placental gene expression of inflammatory markers and growth factors : a case control study of obese and normal weight women
- 2015
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Ingår i: Journal of Perinatal Medicine. - : Walter de Gruyter. - 0300-5577 .- 1619-3997. ; 43:2, s. 159-164
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To survey the placental gene expression of inflammatory markers and growth factors in non-smoking obese women with an uncomplicated pregnancy without associated morbidity and delivery at term compared with normal weight women.Methods: Placental tissue samples from 32 obese women (body mass index, BMI >= 35.0 kg/m(2)) were compared with samples from 94 normal weight women (BMI 18.5-25.0 kg/m(2)) matched for age (+/- 1 year), gestational age (+/- 3 days), parity and mode of delivery. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to analyse toll receptor-2 and -4, interleukin-6 and -8, tumour necrosis factor-alpha, leptin, adiponectin, insulin-like growth factor-1 and -2, hepatocyte growth factor, hepatocyte growth factor receptor and insulin receptor.Results: There was no significant difference in gene expression in placental tissue samples from obese and normal weight women.Conclusion: We found no difference in the occurrence of inflammatory marker and growth factor mRNA levels in placental tissue samples from a large group of obese women without associated morbidity and with healthy infants compared to a closely matched control group of healthy normal weight women. Compared with the previous studies, this anomalous finding may be explained by the absence of associated morbidity in the obese women in our study.
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| 8. |
- Bacos, Karl, et al.
(författare)
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Islet beta-cell area and hormone expression are unaltered in Huntington's disease.
- 2008
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Ingår i: Histochemistry and Cell Biology. - : Springer Science and Business Media LLC. - 1432-119X .- 0948-6143. ; 129, s. 623-629
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Tidskriftsartikel (refereegranskat)abstract
- Neurodegenerative disorders are often associated with metabolic alterations. This has received little attention, but might be clinically important because it can contribute to symptoms and influence the course of the disease. Patients with Huntington's disease (HD) exhibit increased incidence of diabetes mellitus (DM). This is replicated in mouse models of HD, e.g., the R6/2 mouse, in which DM is primarily caused by a deficiency of beta-cells with impaired insulin secretion. Pancreatic tissue from HD patients has previously not been studied and, thus, the pathogenesis of DM in HD is unclear. To address this issue, we examined pancreatic tissue sections from HD patients at different disease stages. We found that the pattern of insulin immunostaining, levels of insulin transcripts and islet beta-cell area were similar in HD patients and controls. Further, there was no sign of amyloid deposition in islets from HD patients. Thus, our data show that pancreatic islets in HD patients appear histologically normal. Functional studies of HD patients with respect to insulin secretion and islet function are required to elucidate the pathogenesis of DM in HD. This may lead to a better understanding of HD and provide novel therapeutic targets for symptomatic treatment in HD.
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| 9. |
- Bjerneby Häll, Maria
(författare)
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Allt har förändrats och allt är sig likt : En longitudinell studie av argument för grundskolans matematikundervisning
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med avhandlingen är att beskriva och analysera argument för matematik i grundskolan och att förstå varför och hur de officiella argumenten förändras, från de argument som återfinns i styrdokument till de argument som förs fram av undervisande matematiklärare. En utgångspunkt är att skolmatematikens villkor och verklighet kan beskrivas genom analys av officiella argument och av lärarstudenters och lärares personliga argument för matematik i grundskolan. Specifika forskningsfrågor i anslutning till syftet är:- Vilka argument för lärarstudenten fram inför yrkesdebuten?- Vilka argument för läraren fram under sina första år i yrket?- Vilka beskrivningar av skolmatematikens villkor ger lärarna?En longitudinell studie har genomförts där en grupp lärarstudenter följts genom utbildningen och under de första åren i yrket. Resultatet visar att lärarstudenter under utbildningen utvecklar en syn på matematik och matematikundervisning som stämmer väl med läroplanen och kursplanen i matematik enligt Lpo 94. De nyblivna lärarna med undervisning i matematik och NO-ämnen upplever i början av yrkeskarriären skilda villkor på olika skolor. Gemensamt för de lärare som undervisar i senare delen av grundskolan är upplevelser av krav på att ”hinna med kursen” inför det nationella provet i årskurs 9. Lärarnas mål med matematikundervisningen i grundskolan blir därför att förbereda eleverna för det nationella provet. En faktor som påverkar är kravet på att elever skall ha betyget godkänd för att vara behöriga till gymnasieskolans nationella program. De nyblivna lärarna upplever en konflikt mellan olika officiella argument för matematik i grundskolan. Faktorer som påverkar lärarnas och matematikämnets villkor och verklighet i grundskolan är bl.a. skolornas organisation i arbetslag och lärarnas kombination av undervisningsämnen.
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| 10. |
- Björkqvist, Maria, et al.
(författare)
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A novel pathogenic pathway of immune activation detectable before clinical onset in Huntington's disease.
- 2008
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 205, s. 1869-1877
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Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by both neurological and systemic abnormalities. We examined the peripheral immune system and found widespread evidence of innate immune activation detectable in plasma throughout the course of HD. Interleukin 6 levels were increased in HD gene carriers with a mean of 16 years before the predicted onset of clinical symptoms. To our knowledge, this is the earliest plasma abnormality identified in HD. Monocytes from HD subjects expressed mutant huntingtin and were pathologically hyperactive in response to stimulation, suggesting that the mutant protein triggers a cell-autonomous immune activation. A similar pattern was seen in macrophages and microglia from HD mouse models, and the cerebrospinal fluid and striatum of HD patients exhibited abnormal immune activation, suggesting that immune dysfunction plays a role in brain pathology. Collectively, our data suggest parallel central nervous system and peripheral pathogenic pathways of immune activation in HD.
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