| 1. |
- Molin, Mikael, 1973, et al.
(författare)
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Protein kinase A controls yeast growth in visible light
- 2020
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Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: A wide variety of photosynthetic and non-photosynthetic species sense and respond to light, having developed protective mechanisms to adapt to damaging effects on DNA and proteins. While the biology of UV light-induced damage has been well studied, cellular responses to stress from visible light (400–700 nm) remain poorly understood despite being a regular part of the life cycle of many organisms. Here, we developed a high-throughput method for measuring growth under visible light stress and used it to screen for light sensitivity in the yeast gene deletion collection. Results: We found genes involved in HOG pathway signaling, RNA polymerase II transcription, translation, diphthamide modifications of the translational elongation factor eEF2, and the oxidative stress response to be required for light resistance. Reduced nuclear localization of the transcription factor Msn2 and lower glycogen accumulation indicated higher protein kinase A (cAMP-dependent protein kinase, PKA) activity in many light-sensitive gene deletion strains. We therefore used an ectopic fluorescent PKA reporter and mutants with constitutively altered PKA activity to show that repression of PKA is essential for resistance to visible light. Conclusion: We conclude that yeast photobiology is multifaceted and that protein kinase A plays a key role in the ability of cells to grow upon visible light exposure. We propose that visible light impacts on the biology and evolution of many non-photosynthetic organisms and have practical implications for how organisms are studied in the laboratory, with or without illumination.
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| 2. |
- Andreasson, Jakob, 1975, et al.
(författare)
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Electron-phonon interactions in perovskites containing Fe and Cr studied by Raman scattering using oxygen-isotope and cation substitution
- 2008
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X .- 2469-9950 .- 2469-9969. ; 78:23, s. 235103-
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Tidskriftsartikel (refereegranskat)abstract
- We use temperature-dependent inelastic light scattering to study the origin of the strong multiphonon scattering of a local oxygen breathing mode present in the mixed B-site orthorhombic (space group Pnma) perovskite LaFe0.5Cr0.5O3 but absent in isostructural LaFeO3 and LaCrO3. It is seen that the multiphonon scattering is critically sensitive to the presence of both Fe and Cr ions on the B site. These results support our interpretation that the multiphonon scattering is activated by local electron-phonon interactions according to the Franck-Condon picture following an Fe-Cr charge transfer. Further, O-18 substitution is performed on the x=0, 0.04, and 0.5 compounds and clearly shows that all modes appearing above the first-order phonon-scattering region in these compounds originate from higher-order oxygen stretching vibrations. In particular this is the case for the strong second-order scattering dominating the scattering response in LaFeO3. Accordingly we propose that these modes are generated by infrared-active longitudinal optical (IR LO) two-phonon and combination scattering activated by Frohlich interaction. For x=0.02 and 0.04 the characteristic IR LO two-phonon and Franck-Condon multiphonon-scattering profiles mix. We also study the influence of isovalent cation substitution and Sr doping in AFe(0.5)Cr(0.5)O(3) (A=La, Nd, and Gd) and La1-ySryFe0.5Cr0.5O3-delta (y=0, 0.16, and 0.5) on the strong electron-phonon coupling present in LaFe0.5Cr0.5O3. The Franck-Condon effect in LaFe0.5Cr0.5O3, is not significantly affected by isovalent A-site substitution, despite the increasing orthorhombic distortion associated with decreasing A-site ionic radii. On the contrary, aliovalent Sr doping causes a rapid decrease in the Franck-Condon scattering. This shows that the strong electron-phonon coupling in these compounds is highly sensitive to local lattice and electronic decoherence but insensitive to global lattice distortions. Finally, a preliminary assignment of the A(g) and B-2g phonon modes in AFe(0.5)Cr(0.5)O(3) (A=La, Nd, and Gd) is made based on the present observations and published results for LaCrO3 and AMnO(3). The modes associated with oxygen octahedral tilt and bending vibrations are heavily influenced by the magnitude of the orthorhombic distortion.
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| 3. |
- Damberg, Mattias, et al.
(författare)
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Investigation of transcription factor AP-2 beta genotype in women with premenstrual dysphoric disorder.
- 2005
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Ingår i: Neuroscience letters. - : Elsevier BV. - 0304-3940. ; 377:1, s. 49-52
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Tidskriftsartikel (refereegranskat)abstract
- It has repeatedly been shown that the serotonergic system is involved in the symptomatology of premenstrual dysphoric disorder (PMDD). Women with PMDD are reported to differ from symptom-free controls with regard to serotonin-related biological markers. Evidence from family and twin studies suggests a genetic contribution to the aetiology of PMDD. The expression of human transcription factor AP-2beta in neural crest cell lineages and neuroectodermal cells suggests that this protein may be of importance for functional characteristics of neurons by regulating the expression of target genes. Within the monoaminergic systems, several genes have binding sites for AP-2beta in regulatory regions, suggesting an involvement of AP-2beta in these systems. The gene encoding AP-2beta is located on chromosome 6p12-p21.1 and includes a polymorphic region consisting of a variable number of [CAAA] repeats located in the second intron. We have earlier shown that AP-2beta genotype is associated with serotonergic phenotypes and that brainstem levels of AP-2beta correlate positively to serotonin metabolism in rat frontal cortex. The aim of this study was to investigate the relationship between PMDD and transcription factor AP-2beta genotype. The participants included 176 women with PMDD and 91 healthy controls. Genotyping was performed by polymerase chain reactions. We did not observe any differences in AP-2beta genotype frequencies between PMDD subjects and controls. Our results suggest that AP-2beta genotype is not a risk factor for PMDD. To our knowledge, this is the first study investigating transcription factor AP-2beta genotype in women with PMDD. Hence, these results should be considered preliminary until replicated.
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| 4. |
- Ekman, Agneta, 1961, et al.
(författare)
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Low density and high affinity of platelet [3H]paroxetine binding in women with bulimia nervosa.
- 2006
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Ingår i: Psychiatry research. - : Elsevier BV. - 0165-1781 .- 1872-7123. ; 142:2-3, s. 219-23
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Tidskriftsartikel (refereegranskat)abstract
- Impaired serotonin transmission has been suggested to be implicated in the pathophysiology of bulimia nervosa. As an indirect measure of brain serotonergic activity, the binding of tritiated ligands to platelet serotonin transporters has been studied in bulimia nervosa as well as in other putatively serotonin-related psychiatric disorders. In this study, the density and affinity of platelet serotonin transporters were assessed in 20 women meeting the DSM-IV criteria for bulimia nervosa and in 14 controls without previous or ongoing eating disorder using [(3)H]paroxetine as a ligand. In comparison to controls, women with bulimia nervosa had a significantly reduced number of platelet binding sites (B(max) = 721 +/- 313 vs. 1145 +/- 293 fmol/mg protein) and an increase in the affinity for the ligand demonstrated by a lower dissociaton constant (K(d) = 33 +/- 10 vs. 44 +/- 10 pM). A significant correlation between B(max) and K(d) values was found in patients but not in controls. Our results support the notion that bulimia nervosa is associated with a reduction in platelet serotonin transporter density. In addition, our study is the first to report that this reduced transporter density in women with bulimia nervosa is accompanied by an increase in the affinity of the transporter for the ligand.
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| 5. |
- Eriksson, Olle, 1954-, et al.
(författare)
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Ovarian morphology in premenstrual dysphoria
- 2012
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 37:6, s. 742-751
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Tidskriftsartikel (refereegranskat)abstract
- Ovarian cyclicity is a prerequisite for premenstrual dysphoria (PMD), as illustrated by the fact that this condition is effectively eliminated by ovariectomy or by treatment with a GnRH agonist. Despite the possibility of differences in ovarian function between women with and without PMD, no study comparing ovarian morphology in these two groups has ever been published. Fifty-two women were recruited for this study; 26 had premenstrual dysphoria, fulfilling criteria slightly modified from those of the premenstrual dysphoric disorder, and 26 were asymptomatic age-matched controls. Ovarian morphology was assessed using transvaginal 7MHz ultrasonography on day 5 after the start of menses, and venous blood was sampled for hormone analysis on days 3 and 8, the expected day of ovulation, and day -4 of the menstrual cycle. There were no significant differences between the groups with respect to the prevalence of polycystic ovaries (PCO), the total number of follicles, the total ovarian volume or serum levels of androgen hormones. In addition, serum free testosterone levels in late premenstrual phase showed an inverse association to premenstrual symptoms of irritability and a similar inverse association trend to symptoms of depressed mood. Unexpectedly, the prevalence of ovaries with fewer than five antral or growing follicles was significantly higher in women with PMD than in controls (p=0.016). While the results do not support a role for PCO or androgen hormones in eliciting late luteal phase irritability, the possible relationship between oligofollicular ovaries and PMD deserves further study.
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| 6. |
- Klaric, Lucija, et al.
(författare)
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Mendelian randomisation identifies alternative splicing of the FAS death receptor as a mediator of severe COVID-19.
- 2021
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Ingår i: medRxiv : the preprint server for health sciences. - : Cold Spring Harbor Laboratory. ; , s. 1-28
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Severe COVID-19 is characterised by immunopathology and epithelial injury. Proteomic studies have identified circulating proteins that are biomarkers of severe COVID-19, but cannot distinguish correlation from causation. To address this, we performed Mendelian randomisation (MR) to identify proteins that mediate severe COVID-19. Using protein quantitative trait loci (pQTL) data from the SCALLOP consortium, involving meta-analysis of up to 26,494 individuals, and COVID-19 genome-wide association data from the Host Genetics Initiative, we performed MR for 157 COVID-19 severity protein biomarkers. We identified significant MR results for five proteins: FAS, TNFRSF10A, CCL2, EPHB4 and LGALS9. Further evaluation of these candidates using sensitivity analyses and colocalization testing provided strong evidence to implicate the apoptosis-associated cytokine receptor FAS as a causal mediator of severe COVID-19. This effect was specific to severe disease. Using RNA-seq data from 4,778 individuals, we demonstrate that the pQTL at the FAS locus results from genetically influenced alternate splicing causing skipping of exon 6. We show that the risk allele for very severe COVID-19 increases the proportion of transcripts lacking exon 6, and thereby increases soluble FAS. Soluble FAS acts as a decoy receptor for FAS-ligand, inhibiting apoptosis induced through membrane-bound FAS. In summary, we demonstrate a novel genetic mechanism that contributes to risk of severe of COVID-19, highlighting a pathway that may be a promising therapeutic target.
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| 7. |
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| 8. |
- Landén, Mikael, 1966, et al.
(författare)
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Compounds with affinity for serotonergic receptors in the treatment of premenstrual dysphoria: a comparison of buspirone, nefazodone and placebo.
- 2001
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Ingår i: Psychopharmacology. - 0033-3158. ; 155:3, s. 292-8
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: It is well established that serotonin reuptake inhibitors (SRIs) are effective for the treatment of premenstrual dysphoria (PMD), but the receptor subtype(s) mediating this effect of serotonin have yet not been identified. OBJECTIVE: In this trial, the possible efficacy of buspirone, a partial 5HT1A receptor agonist, and nefazodone, a combined SRI and 5HT2 receptor antagonist, was evaluated in women with PMD. METHODS: After a three-menstrual-cycle screening phase, patients were randomised to buspirone (n=19), nefazodone (n=22) or placebo (n=22). During the first two treatment cycles, patients were taking the drug during the luteal phase only (mean +/- SD daily dose of buspirone: 21 +/- 6 mg; nefazodone: 228 +/- 54 mg). During the subsequent two cycles, the medication was taken each day of the menstrual cycle (mean daily dose of buspirone: 27 +/- 10 mg; nefazodone: 304 +/- 95 mg). RESULTS: With respect to self-rated global improvement, buspirone (P<0.001) but not nefazodone was significantly superior to placebo. While buspirone appeared to reduce self-rated irritability (visual analogue scale) more effectively than placebo, other self-rated symptoms did not differ markedly between the groups. The side-effects were mild, and sexual dysfunction was not significantly more common in patients given buspirone or nefazodone than in those given placebo. CONCLUSION: It is suggested that buspirone is mildly effective for premenstrual irritability. In patients experiencing sexual dysfunction when treated with an SRI, buspirone may be a useful alternative.
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| 9. |
- Melke, Jonas, 1971, et al.
(författare)
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Serotonin transporter gene polymorphisms and platelet [3H] paroxetine binding in premenstrual dysphoria.
- 2003
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Ingår i: Psychoneuroendocrinology. - 0306-4530. ; 28:3, s. 446-58
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate if women with premenstrual dysphoria differ from controls with respect to the number of platelet serotonin transporters, and with respect to three polymorphisms in the gene coding for the serotonin transporter: a 44 base pair insertion/deletion in the promoter region, a variable number of tandem repeats in the second intron, and a single nucleotide polymorphism in the 3' untranslated region. Also, the possible relationship between the three polymorphisms and platelet serotonin transporter density was analyzed. The density of platelet [(3)H]paroxetine binding sites was significantly lower in women with premenstrual dysphoria than in controls, but patients and controls did not differ with respect to allele or genotype frequency for any of the three polymorphisms examined. A significant association between the number of platelet serotonin transporters and the promoter polymorphism was observed, subjects being homozygous for the short (deletion) variant having higher platelet serotonin transporter density than subjects carrying the long (insertion) allele. The results support the assumption that serotonin-related psychiatric disorders-such as premenstrual dysphoria-may be associated with a reduction in platelet [(3)H]paroxetine binding, but argue against the notion that this reduction is due to certain variants of the serotonin transporter gene being more common in patients than in controls.
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| 10. |
- Sundblad-Elverfors, Charlotta, 1959, et al.
(författare)
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Effects of the androgen antagonist flutamide and the serotonin reuptake inhibitor citalopram in bulimia nervosa: a placebo-controlled pilot study.
- 2005
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Ingår i: Journal of clinical psychopharmacology. - : Ovid Technologies (Wolters Kluwer Health). - 0271-0749. ; 25:1, s. 85-8
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Tidskriftsartikel (refereegranskat)abstract
- Prompted by previous studies suggesting that bulimia nervosa in women may be associated with elevated serum levels of testosterone, we have evaluated the possible effect of androgen antagonism in this condition. To this end, women meeting the DSM-IV criteria of bulimia nervosa, purging type, were treated in a one-center study with the androgen receptor antagonist flutamide (n = 9), the serotonin reuptake inhibitor citalopram (n = 15), flutamide plus citalopram (n = 10), or placebo (n = 12) for 3 months using a double-blind design. Self-rated global assessment of symptom intensity suggests all active treatments to be superior to placebo. The reduction in binge eating compared with baseline was statistically significant in both groups given flutamide but not in the groups given citalopram only or placebo. A moderate and reversible increase in serum transaminase levels led to discontinuation in two subjects in the flutamide group. It is concluded that blockade of androgen receptors may reduce some of the symptoms of bulimia nervosa in women.
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