| 1. |
- Lindqvist, Christina, et al.
(author)
-
Transmission of Stress-Induced Learning Impairment and Associated Brain Gene Expression from Parents to Offspring in Chickens
- 2007
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 2:4, s. e364-
-
Journal article (peer-reviewed)abstract
- Background: Stress influences many aspects of animal behaviour and is a major factor driving populations to adapt to changing living conditions, such as during domestication. Stress can affect offspring through non-genetic mechanisms, but recent research indicates that inherited epigenetic modifications of the genome could possibly also be involved. Methodology/Principal Findings: Red junglefowl (RJF, ancestors of modern chickens) and domesticated White Leghorn (WL) chickens were raised in a stressful environment (unpredictable light-dark rhythm) and control animals in similar pens, but on a 12/12 h light-dark rhythm. WL in both treatments had poorer spatial learning ability than RJF, and in both populations, stress caused a reduced ability to solve a spatial learning task. Offspring of stressed WL, but not RJF, raised without parental contact, had a reduced spatial learning ability compared to offspring of non-stressed animals in a similar test as that used for their parents. Offspring of stressed WL were also more competitive and grew faster than offspring of non-stressed parents. Using a whole-genome cDNA microarray, we found that in WL, the same changes in hypothalamic gene expression profile caused by stress in the parents were also found in the offspring. In offspring of stressed WL, at least 31 genes were up- or down-regulated in the hypothalamus and pituitary compared to offspring of non-stressed parents. Conclusions/ Significance: Our results suggest that, in WL the gene expression response to stress, as well as some behavioural stress responses, were transmitted across generations. The ability to transmit epigenetic information and behaviour modifications between generations may therefore have been favoured by domestication. The mechanisms involved remain to be investigated; epigenetic modifications could either have been inherited or acquired de novo in the specific egg environment. In both cases, this would offer a novel explanation to rapid evolutionary adaptation of a population.
|
|
| 2. |
|
|
| 3. |
- Kadkhodaei, Banafsheh, et al.
(author)
-
Nurr1 Is Required for Maintenance of Maturing and Adult Midbrain Dopamine Neurons
- 2009
-
In: The Journal of Neuroscience. - 1529-2401. ; 29:50, s. 15923-15932
-
Journal article (peer-reviewed)abstract
- Transcription factors involved in the specification and differentiation of neurons often continue to be expressed in the adult brain, but remarkably little is known about their late functions. Nurr1, one such transcription factor, is essential for early differentiation of midbrain dopamine (mDA) neurons but continues to be expressed into adulthood. In Parkinson's disease, Nurr1 expression is diminished and mutations in the Nurr1 gene have been identified in rare cases of disease; however, the significance of these observations remains unclear. Here, a mouse strain for conditional targeting of the Nurr1 gene was generated, and Nurr1 was ablated either at late stages of mDA neuron development by crossing with mice carrying Cre under control of the dopamine transporter locus or in the adult brain by transduction of adeno-associated virus Cre-encoding vectors. Nurr1 deficiency in maturing mDA neurons resulted in rapid loss of striatal DA, loss of mDA neuron markers, and neuron degeneration. In contrast, a more slowly progressing loss of striatal DA and mDA neuron markers was observed after ablation in the adult brain. As in Parkinson's disease, neurons of the substantia nigra compacta were more vulnerable than cells in the ventral tegmental area when Nurr1 was ablated at late embryogenesis. The results show that developmental pathways play key roles for the maintenance of terminally differentiated neurons and suggest that disrupted function of Nurr1 and other developmental transcription factors may contribute to neurodegenerative disease.
|
|
| 4. |
- Kess, Daniel, et al.
(author)
-
Identification of susceptibility loci for skin disease in a murine psoriasis model
- 2006
-
In: Journal of Immunology. - 1550-6606. ; 177:7, s. 4612-4619
-
Journal article (peer-reviewed)abstract
- Psoriasis is a frequently occurring inflammatory skin disease characterized by thickened erythematous skin that is covered with silvery scales. It is a complex genetic disease with both heritable and environmental factors contributing to onset and severity. The CD18 hypomorphic PL/J mouse reveals reduced expression of the common chain of beta(2) integrins (CD11/CD18) and spontaneously develops a skin disease that closely resembles human psoriasis. In contrast, CD18 hypomorphic C57BL/6J mice do not demonstrate this phenotype. In this study, we have performed a genome-wide scan to identify loci involved in psoriasiform dermatitis under the condition of low CD18 expression. Backcross analysis of a segregating cross between susceptible CD18 hypomorphic PL/J mice and the resistant CD18 hypomorphic C57BL/6J strain was performed. A genome-wide linkage analysis of 94 phenotypically extreme mice of the backcross was undertaken. Thereafter, a complementary analysis of the regions of interest from the genome-wide screen was done using higher marker density and further mice. We found two loci on chromosome 10 that were significantly linked to the disease and interacted in an additive fashion in its development. In addition, a locus on chromosome 6 that promoted earlier onset of the disease was identified in the most severely affected mice. For the first time, we have identified genetic regions associated with psoriasis in a mouse model resembling human psoriasis. The identification of gene regions associated with psoriasis in this mouse model might contribute to the understanding of genetic causes of psoriasis in patients and pathological mechanisms involved in development of disease.
|
|
| 5. |
- Lindqvist, Daniel, et al.
(author)
-
Interleukin-6 Is Elevated in the Cerebrospinal Fluid of Suicide Attempters and Related to Symptom Severity
- 2009
-
In: BIOLOGICAL PSYCHIATRY. - : Elsevier BV. - 0006-3223 .- 1873-2402. ; 66:3, s. 287-292
-
Journal article (peer-reviewed)abstract
- Background: Depressive disorders are associated with immune system alterations that can be detected in the blood. Cytokine concentrations in cerebrospinal fluid (CSF) and their relationship to aspects of suicidality have previously not been investigated. Methods: We measured interleukin-1 beta interleukin-6 (IL-6), interleukin-8, and tumor necrosis factor-a (TNF-alpha) in CSF and plasma of suicide attempters (n = 63) and healthy control subjects (n = 47). Patients were classified according to diagnosis and violent or nonviolent suicide attempt. We evaluated suicidal ideation and depressive symptoms using the Suicide Assessment Scale and the Montgomery-Asberg Depression Rating Scale (MADRS). We also analyzed the relation between cytokines and monoamine metabolites 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in CSF, as well as the integrity of the blood-brain barrier as reflected by the CSF:serum albumin ratio. Results: IL-6 in CSF was significantly higher in suicide attempters than in healthy control subjects. Patients who performed violent suicide attempts displayed the highest IL-6. Furthermore, there was a significant positive correlation between MANS scores and CSF IL-6 levels in all patients. IL-6 and TNF-a correlated significantly with 5-HIAA and HVA in CSF, but not with MHPG. Cytokine levels in plasma and CSF were not associated, and patients with increased blood-brain barrier permeability did not exhibit elevated cytokine levels. Conclusions: We propose a role for CSF IL-6 in the symptomatology of suicidal behavior, possibly through mechanisms involving alterations of dopamine and serotonin metabolism.
|
|
| 6. |
- Lindqvist, Daniel, et al.
(author)
-
Salivary cortisol and suicidal behavior-A follow-up study.
- 2008
-
In: Psychoneuroendocrinology. - : Elsevier BV. - 1873-3360 .- 0306-4530. ; 33:8, s. 1061-1068
-
Journal article (peer-reviewed)abstract
- INTRODUCTION: Hyperactivity of the hypothalamic-pituitary-adrenal (HPA)-axis is a common finding in major depressive disorder. Similar studies on suicide attempters are less abundant, and the results are divergent. The main aim of the present study was to investigate HPA-axis parameters by the time of a suicide attempt and at follow-up in search for associations between HPA-axis function and suicidal behavior. METHODS: Thirty-five suicide attempters and 16 non-suicidal controls were admitted to a psychiatric ward between the years of 1986 and 1992. Corticotrophin-releasing hormone (CRH) in cerebrospinal fluid and urinary cortisol were obtained for the suicide attempters. The patients were followed up approximately 12 years after the index admission. Cortisol was measured in saliva, and additional suicide attempts and current psychiatric symptoms were registered. RESULTS: At follow-up, evening salivary cortisol was lower in suicide attempters compared to controls. Low cortisol levels at follow-up were associated with severe psychiatric symptoms. Among women, repeated suicide attempts were associated with low morning and lunch salivary cortisol, and in this subgroup we also found significant correlations between salivary cortisol at follow-up, and CRH as well as urinary cortisol at index. CONCLUSION: We found evidence for an association between low HPA-axis activity and suicidal behavior. This could be due to long-lasting and severe psychiatric morbidity, which in turn has exhausted the HPA-axis of these patients. The potential role of hypocortisolism should be given more attention in studies on suicidal patients.
|
|
| 7. |
- Lindqvist, Daniel, et al.
(author)
-
Suicidal intent and psychiatric symptoms among inpatient suicide attempters.
- 2007
-
In: Nordic Journal of Psychiatry. - : Informa UK Limited. - 1502-4725 .- 0803-9488. ; 61:1, s. 27-32
-
Journal article (peer-reviewed)abstract
- The objective of this study was to investigate associations between suicidal intent and psychiatric symptoms, and to study the usefulness of the Suicidal Intent Scale (SIS) and the Comprehensive Psychopathological Rating Scale (CPRS) for suicide risk assessment in an inpatient population. One hundred and ninety-six suicide attempters, of whom 15 eventually committed suicide, were admitted to a psychiatric ward. They were assessed by means of the SIS and the CPRS. Cox regression analyses were performed in order to adjust the relationships between the individual CPRS subscales and suicide for age and gender. The patients who later completed suicide had higher scores on the CPRS than the patients who did not complete suicide. We found no associations between symptoms and suicidal intent. The severity of psychopathology, in terms of high CPRS scores, shows a stronger association with future suicide than the level of suicidal intent (SIS) among inpatient suicide attempters. Suicidal intent is evidently scored regardless of psychiatric symptoms.
|
|
| 8. |
- Lindqvist, Daniel, et al.
(author)
-
Suicidal Intent and the HPA-Axis Characteristics of Suicide Attempters with Major Depressive Disorder and Adjustment Disorders.
- 2008
-
In: Archives of Suicide Research. - : Informa UK Limited. - 1543-6136 .- 1381-1118. ; 12:3, s. 197-207
-
Journal article (peer-reviewed)abstract
- The main purpose of the study was to investigate Hypothalamic-Pituitary-Adrenal (HPA) axis characteristics in relation to suicidal intent among suicide attempters with Major Depressive Disorder (MDD) and Adjustment Disorders (AD). The relationship between suicidal intent, assessed by means of the Suicidal Intent Scale (SIS), and serum cortisol after a Dexamethasone Suppression Test (DST) was investigated in 78 suicide attempters, divided into diagnostic subgroups. There was a significant negative correlation between suicidal intent and post DST cortisol in patients with MDD. Our findings may be attributed to pathophysiological processes, where a high suicidal intent is revealed during a potential chronic course of MDD, which in turnresults in a seemingly normal stress system.
|
|
| 9. |
- Lindqvist, Josefina, et al.
(author)
-
Intelligent Dual-Responsive Cellulose Surfaces via Surface-Initiated ATRP
- 2008
-
In: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 9:8, s. 2139-2145
-
Journal article (peer-reviewed)abstract
- Novel thermo-responsive cellulose (filter paper) surfaces of N-isopropylacrylamide (NIPAAm) and pH-responsive cellulose surfaces of 4-vinylpyridine (4VP) have been achieved via surface-initiated ATRP. Dual-responsive (pH and temperature) cellulose surfaces were also obtained through the synthesis of block-copolymer brushes of PNIPAAm and P4VP. With changes in pH and temperature, these "intelligent" surfaces showed a reversible response to both individual triggers, as indicated by the changes in wettability from highly hydrophilic to highly hydrophobic observed by water contact angle measurements. Adjusting the composition of the grafted block-copolymer brushes allowed for further tuning of the wettability of these "intelligent" cellulose surfaces.
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
- Nyström, Daniel, et al.
(author)
-
Superhydrophobic and self-cleaning bio-fiber surfaces via ATRP and subsequent postfunctionalization
- 2009
-
In: ACS applied materials & interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 1:4, s. 816-823
-
Journal article (peer-reviewed)abstract
- Superhydrophobic and self-cleaning cellulose surfaces have been obtained via surface-confined grafting of glycidyl methacrylate using atom transfer radical polymerization combined with postmodification reactions. Both linear and branched graft-on-graft architectures were used for the postmodification reactions to obtain highly hydrophobic bio-fiber surfaces by functionalization of the grafts with either poly(dimethylsiloxane), perfluorinated chains, or alkyl chains, respectively, Postfunctionalization using alkyl chains yielded results similar to those of surfaces modified by perfluorination, in terms of superhydrophobicity, self-cleaning properties, and the stability of these properties over time. in addition, highly oleophobic surfaces have been obtained when modification with perfluorinated chains was performed.
|
|
| 15. |
- Nyström, Daniel, et al.
(author)
-
Superhydrophobic Bio-fibre Surfaces via Tailored Grafting Architecture
- 2006
-
In: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; :34, s. 3594-3596
-
Journal article (peer-reviewed)abstract
- Superhydrophobic bio-fibre surfaces with a micro-nano-binary surface structure have been achieved via the surface-confined grafting of glycidyl methacrylate, using a branched "graft-on-graft'' architecture, followed by post-functionalisation to obtain fluorinated brushes.
|
|
| 16. |
- Nätt, Daniel, et al.
(author)
-
Inheritance of Acquired Behaviour Adaptions and Brain Gene Expression in Chickens
- 2009
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 4:7, s. e6405-
-
Research review (other academic/artistic)abstract
- Background: Environmental challenges may affect both the exposed individuals and their offspring. We investigated possible adaptive aspects of such cross-generation transmissions, and hypothesized that chronic unpredictable food access would cause chickens to show a more conservative feeding strategy and to be more dominant, and that these adaptations would be transmitted to the offspring. Methodology/Principal Findings: Parents were raised in an unpredictable (UL) or in predictable diurnal light rhythm (PL, 12:12 h light:dark). In a foraging test, UL birds pecked more at freely available, rather than at hidden and more attractive food, compared to birds from the PL group. Female offspring of UL birds, raised in predictable light conditions without parental contact, showed a similar foraging behavior, differing from offspring of PL birds. Furthermore, adult offspring of UL birds performed more food pecks in a dominance test, showed a higher preference for high energy food, survived better, and were heavier than offspring of PL parents. Using cDNA microarrays, we found that the differential brain gene expression caused by the challenge was mirrored in the offspring. In particular, several immunoglobulin genes seemed to be affected similarly in both UL parents and their offspring. Estradiol levels were significantly higher in egg yolk from UL birds, suggesting one possible mechanism for these effects. Conclusions/Significance: Our findings suggest that unpredictable food access caused seemingly adaptive responses in feeding behavior, which may have been transmitted to the offspring by means of epigenetic mechanisms, including regulation of immune genes. This may have prepared the offspring for coping with an unpredictable environment. Citation: Nätt D, Lindqvist N, Stranneheim H, Lundeberg J, Torjesen PA, et al. (2009) Inheritance of Acquired Behaviour Adaptations and Brain Gene Expression in Chickens. PLoS ONE 4(7): e6405. doi:10.1371/journal.pone.0006405 Editor: Tom Pizzari, University of Oxford, United Kingdom Received: March 26, 2009; Accepted: June 30, 2009; Published: July 28, 2009 Copyright: © 2009 Nätt et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This project was funded by the Swedish Research Council (VR; www.vr.se; grant nrs 50280101 and 50280102) and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas; www.formas.se; grant no 221-2005-270). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the mauscript. Competing interests: The authors have declared that no competing interests exist.
|
|
| 17. |
- Wang, Honglin, et al.
(author)
-
A 9-centimorgan interval of chromosome 10 controls the T cell-dependent psoriasiform skin disease and arthritis in a murine psoriasis model
- 2008
-
In: Journal of Immunology. - 1550-6606. ; 180:8, s. 5520-5529
-
Journal article (peer-reviewed)abstract
- Psoriasis is a complex genetic disease of unresolved pathogenesis with both heritable and environmental factors contributing to onset and severity. In addition to a disfiguring skin inflammation, approximately 10-40% of psoriasis patients suffer from destructive joint involvement. Previously, we reported that the CD18 hypomorphic PL/J mouse carrying a mutation resulting in reduced expression of the common chain of beta(2) integrins (CD11/CD18) spontaneously develops a skin disease that closely resembles human psoriasis. In contrast, the same mutation on C57BL/6J background did not demonstrate this phenotype. By a genome-wide linkage analysis, two major loci were identified as contributing to the development of psoriasiform dermatitis under the condition of low CD18 expression. Using a congenic approach, we now demonstrate that the introduction of a 9-centimorgan fragment of chromosome 10 derived from the PL/J strain into the disease-resistant CD18 hypomorphic C57BL/6J was promoting the development of psoriasiform skin disease and notably also arthritis. We therefore designated this locus psoriasiform skin disease-associated locus 1 (PSD1). High numbers of CD4(+) T cells and TNF-alpha producing macrophages were detected both in inflamed skin and joints in these congenic mice, with a complete resolution upon TNF-alpha inhibitor therapy or depletion of CD4(+) T cells. For the first time, we have identified a distinct genetic element that contributes to the T cell-dependent development of both psoriasiform skin disease and associated arthritis. This congenic model will be suitable to further investigations of genetic and molecular pathways that cause psoriasiform dermatitis and arthritis, and it may also be relevant for other autoimmune diseases.
|
|
| 18. |
- Östmark, Emma, et al.
(author)
-
Dendronized Hydroxypropyl Cellulose : Synthesis and Characterization of Biobased Nanoobjects
- 2007
-
In: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 8:12, s. 3815-3822
-
Journal article (peer-reviewed)abstract
- Dendronized polymers containing a cellulose backbone have been synthesized with the aim of producing complex molecules with versatile functionalization possibilites and high molecular weight from biobased starting materials. The dendronized polymers were built by attaching premade acetonide-protected 2,2-bis(methylol)propionic acid functional dendrons of generation one to three to a hydroxypropyl cellulose backbone. Deprotection or functionalization of the end groups of the first generation dendronized polymer to hydroxyl groups and long alkyl chains was performed, respectively. The chemical structures of the dendronized polymers were confirmed through analysis using H-1 NMR and FT-IR spectroscopies. From SEC analysis, the dendronized polymers were found to have an increasing polystyrene-equivalent molecular weight up to the second generation (M-n = 50 kg mol(-1)), whereas the polystyrene-equivalent molecular weight for the third generation was lower than for the second, although the same grafting density was obtained from H-1 NMR spectroscopy for the second and third generations. Tapping-mode atomic force microscopy was used to characterize the properties of the dendronized polymers in the dry state, exploring both the effect of the polar substrate mica and the less polar substrate highly oriented pyrolytic graphite (HOPG). It was found that the molecules were in the size range of tens of nanometers and that they were apt to undertake a more elongated conformation on the HOPG surfaces when long alkyl chains were attached as the dendron end-groups.
|
|
| 19. |
|
|
