| 161. |
- Herrmann, Uli S., et al.
(författare)
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Structure-based drug design identifies polythiophenes as antiprion compounds
- 2015
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Ingår i: Science Translational Medicine. - : AMER ASSOC ADVANCEMENT SCIENCE. - 1946-6234 .- 1946-6242. ; 7:299, s. 299ra123-
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Tidskriftsartikel (refereegranskat)abstract
- Prions cause transmissible spongiform encephalopathies for which no treatment exists. Prions consist of PrPSc, a misfolded and aggregated form of the cellular prion protein (PrPC). We explore the antiprion properties of luminescent conjugated polythiophenes (LCPs) that bind and stabilize ordered protein aggregates. By administering a library of structurally diverse LCPs to the brains of prion-infected mice via osmotic minipumps, we found that antiprion activity required a minimum of five thiophene rings bearing regularly spaced carboxyl side groups. Solid-state nuclear magnetic resonance analyses and molecular dynamics simulations revealed that anionic side chains interacted with complementary, regularly spaced cationic amyloid residues of model prions. These findings allowed us to extract structural rules governing the interaction between LCPs and protein aggregates, which we then used to design a new set of LCPs with optimized binding. The new set of LCPs showed robust prophylactic and therapeutic potency in prion-infected mice, with the lead compound extending survival by greater than80% and showing activity against both mouse and hamster prions as well as efficacy upon intraperitoneal administration into mice. These results demonstrate the feasibility of targeted chemical design of compounds that may be useful for treating diseases of aberrant protein aggregation such as prion disease.
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| 162. |
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| 163. |
- Huber, M., et al.
(författare)
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Phase memory relaxation times of spin labels in human carbonic anhydrase II : Pulsed EPR to determine spin label location
- 2001
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Ingår i: Biophysical Chemistry. - 0301-4622 .- 1873-4200. ; 94:3, s. 245-256
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Tidskriftsartikel (refereegranskat)abstract
- Phase memory relaxation times (TM or T2) of spin labels in human carbonic anhydrase II (HCA II) are reported. Spin labels (N-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolidinyl)iodoacetamide, IPSL) were introduced at cysteines, by site-directed mutagenesis at seven different positions in the protein. By two pulse electron paramagnetic resonance (EPR), electron spin echo decays at 45 K are measured and fitted by stretched exponentials, resulting in relaxation parameters TM and x. TM values of seven positions are between 1.6 ╡s for the most buried residue (L79C) and 4.7 ╡s for a residue at the protein surface (W245C). In deuteriated buffer, longer TM are found for all but the most buried residues (L79C and W97C), and electron spin echo envelop modulation (ESEEM) of deuterium nuclei is observed. Different deuterium ESEEM patterns for W95C and W16C (surface residue) indicate differences in the local water concentration, or accessibility, of the spin label by deuterium. We propose TM as a parameter to determine the spin label location in proteins. Furthermore, these systems are interesting for studying the pertaining relaxation mechanism. ⌐ 2001 Elsevier Science B.V. All rights reserved.
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| 164. |
- Jiang, R. C., et al.
(författare)
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Increased CSF-decorin predicts brain pathological changes driven by Alzheimer's A beta amyloidosis
- 2022
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Ingår i: Acta Neuropathologica Communications. - : Springer Science and Business Media LLC. - 2051-5960. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) biomarkers play an important role in diagnosing Alzheimer's disease (AD) which is characterized by amyloid-beta (A beta) amyloidosis. Here, we used two App knock-in mouse models, App(NL-F/NL-F) and App(NL-G-F/NL-G-F), exhibiting AD-like A beta pathology to analyze how the brain pathologies translate to CSF proteomes by label-free mass spectrometry (MS). This identified several extracellular matrix (ECM) proteins as significantly altered in App knock-in mice. Next, we compared mouse CSF proteomes with previously reported human CSF MS results acquired from patients across the AD spectrum. Intriguingly, the ECM protein decorin was similarly and significantly increased in both App(NL-F/NL-F) and App(NL-G-F/NL-G-F) mice, strikingly already at three months of age in the App(NL-F/NL-F) mice and preclinical AD subjects having abnormal CSF-A beta 42 but normal cognition. Notably, in this group of subjects, CSF-decorin levels positively correlated with CSF-A beta 42 levels indicating that the change in CSF-decorin is associated with early A beta amyloidosis. Importantly, receiver operating characteristic analysis revealed that CSF-decorin can predict a specific AD subtype having innate immune activation and potential choroid plexus dysfunction in the brain. Consistently, in App(NL-F/NL-F) mice, increased CSF-decorin correlated with both AP plaque load and with decorin levels in choroid plexus. In addition, a low concentration of human A beta 42 induces decorin secretion from mouse primary neurons. Interestingly, we finally identify decorin to activate neuronal autophagy through enhancing lysosomal function. Altogether, the increased CSF-decorin levels occurring at an early stage of A beta amyloidosis in the brain may reflect pathological changes in choroid plexus, present in a subtype of AD subjects.
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| 165. |
- Johansson, Klara, et al.
(författare)
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Neighbourhood disadvantage and individual adversities in adolescence and total alcohol consumption up to mid-life : Results from the Northern Swedish Cohort
- 2015
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Ingår i: Health and Place. - : Elsevier BV. - 1353-8292 .- 1873-2054. ; 33, s. 187-194
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Tidskriftsartikel (refereegranskat)abstract
- This study tests if neighbourhood socioeconomic disadvantage and family social and material adversities during adolescence are independently related to total alcohol consumption from adolescence through to mid-life. Self-reports from the Northern Swedish Cohort (effective sample=950) at ages 16, 18, 21, 30 and 42 was combined with register data on the socioeconomic composition of neighbourhoods at age 16. Total volume of alcohol consumed between age 16-42 was estimated based on the five survey waves, and self-reported social and material adversities were computed as composite variables. Neighbourhood socioeconomic disadvantage at age 16 was associated with alcohol consumption age 16-42 for men but not for women. Social adversities at age 16 were associated with alcohol consumption age 16-42 for both women and men, but material adversity or parental class was not. In conclusion, neighbourhood socioeconomic disadvantage in adolescence has a significant relationship with later alcohol consumption among men, even independently from individual factors. On family level, social factors but not socioeconomic factors in adolescence independently predict later alcohol consumption.
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| 166. |
- Johansson, Lovisa, et al.
(författare)
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Amyloid beta 1-40 and 1-42 fibril ratios and maturation level cause conformational differences with minimal impact on autophagy and cytotoxicity
- 2024
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Ingår i: Journal of Neurochemistry. - : WILEY. - 0022-3042 .- 1471-4159.
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Tidskriftsartikel (refereegranskat)abstract
- The amyloid beta (A beta) peptide has a central role in Alzheimer's disease (AD) pathology. The peptide length can vary between 37 and 49 amino acids, with A beta 1-42 being considered the most disease-related length. However, A beta 1-40 is also found in A beta plaques and has shown to form intertwined fibrils with A beta 1-42. The peptides have previously also shown to form different fibril conformations, proposed to be related to disease phenotype. To conduct more representative in vitro experiments, it is vital to uncover the impact of different fibril conformations on neurons. Hence, we fibrillized different A beta 1-40:42 ratios in concentrations of 100:0, 90:10, 75:25, 50:50, 25:75, 10:90 and 0:100 for either 24 h (early fibrils) or 7 days (aged fibrils). These were then characterized based on fibril width, LCO-staining and antibody-staining. We further challenged differentiated neuronal-like SH-SY5Y human cells with the different fibrils and measured A beta content, cytotoxicity and autophagy function at three different time-points: 3, 24, and 72 h. Our results revealed that both A beta 1-40:42 ratio and fibril maturation affect conformation of fibrils. We further show the impact of these conformation changes on the affinity to commonly used A beta antibodies, primarily affecting A beta 1-40 rich aggregates. In addition, we demonstrate uptake of the aggregates by neuronally differentiated human cells, where aggregates with higher A beta 1-42 ratios generally caused higher cellular levels of A beta. These differences in A beta abundance did not cause changes in cytotoxicity nor in autophagy activation. Our results show the importance to consider conformational differences of A beta fibrils, as this can have fundamental impact on A beta antibody detection. Overall, these insights underline the need for further exploration of the impact of conformationally different fibrils and the need to reliably produce disease relevant A beta aggregates.image
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| 167. |
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| 168. |
- Jonson, Maria
(författare)
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Investigating Amyloid β toxicity in Drosophila melanogaster
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis Drosophila melanogaster (the fruit fly) has been used as a model organism to study the aggregation and toxic properties of the human amyloid β (Aβ) peptide involved in the onset of Alzheimer's disease (AD). AD is one of many misfolding diseases where the important event of a protein to adopt its’ specific three-dimensional structure has failed, leading to aggregation and formation of characteristic amyloid fibrils. AD has a complex pathology and probably reflects a variety of related molecular and cellular abnormalities, however, the most apparent common denominator so far is abnormal Amyloid-β precursor protein (APP) processing, resulting in a pool of various Aβ-peptides. In AD, the Aβ peptide misfolds, aggregates and forms amyloid plaques in the brain of patients, resulting in progressive neurodegeneration that eventually leads to death.By expressing the human Aβ protein in the fly, we have studied the mechanisms and toxicity of the aggregation in detail and how different cell types in the fly are affected. We have also used this model to investigate the effect of potential drugs that can have a positive impact on disease progression. In the first and second work in this thesis, we have, in a systematic way, proved that the length of the Aβ-peptide is essential for its toxicity and propensity to aggregate. If the peptide expressed ends at amino acid 42 it is extremely toxic to the fly nervous system. However, this toxicity can be completely abolished by expressing a variant that is shorter than 42 amino acids (1-37 to 1-41 aa), or be significantly reduced by expressing a longer variant (1-43 aa). Toxicity can be partly mitigated in trans by co-expressing the 1-42 variant with a 1-38 variant. This supports the theory that the disease progression could be inhibited if the formation of Aβ 1-42 is decreased. In the third work we demonstrate that amyloid aggregates can be found in various cell types of Drosophila, however, the toxicity seem to be selective to neurons. Our results indicate that the aggregates of glial expressing flies have a more mature structure, which appear to be less toxic. This also suggests that glial cells might spread Aβ aggregates without being harmed. The last work in this thesis investigates how curcumin (turmeric) can affect Aβ aggregation and toxicity. Curcumin appears to shift the equilibrium between the less stableaggregates and mature fibers toward the final stage resulting in an improved lifespan for treated flies.In summary, this thesis demonstrates that the toxicity of Aβ in Drosophila is highly dependent on the Aβ variant expressed, the structure of the protein aggregates and which cell type that expresses the protein. We have also shed light on the potential of using Drosophila when it comes to examining possible therapeutic substances as a tool for drug discovery.
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| 169. |
- Jonsson, Frida, et al.
(författare)
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Are neighbourhood inequalities in adult health explained by socio-economic and psychosocial determinants in adolescence and the subsequent life course in northern Sweden? : A decomposition analysis
- 2018
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Ingår i: Health and Place. - : Elsevier. - 1353-8292 .- 1873-2054. ; 52, s. 127-134
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Tidskriftsartikel (refereegranskat)abstract
- This study explains neighbourhood deprivation inequalities in adult health for a northern Swedish cohort by examining the contribution of socio-economic and psychosocial determinants from adolescence (age 16), young adulthood (age 21) and midlife (age 42) to the disparity. Self-reported information from 873 participants was drawn from questionnaires, with complementary neighbourhood register data. The concentration index was used to estimate the inequality while decomposition analyses were run to attribute the disparity to its underlying determinants. The results suggest that socio-economic and psychosocial factors in midlife explain a substantial part, but also that the inequality can originate from conditions in adolescence and young adulthood.
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| 170. |
- Jonsson, Frida, et al.
(författare)
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Intragenerational social mobility and functional somatic symptoms in a northern Swedish context : analyses of diagonal reference models
- 2017
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Ingår i: International Journal for Equity in Health. - : Springer Science and Business Media LLC. - 1475-9276. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Research indicate that social class mobility could be potentially important for health, but whether this is due to the movement itself or a result of people having been integrated in different class contexts is, to date, difficult to infer. In addition, although several theories suggest that transitions between classes in the social hierarchy can be stressful experiences, few studies have empirically examined whether such movements may have health effects, over and above the implications of "being" in these classes. In an attempt to investigate whether intragenerational social mobility is associated with functional somatic symptoms in mid-adulthood, the current study tests three partially contrasting theories.METHOD: The dissociative theory suggests that mobility in general and upward mobility in particular may be linked to psychological distress, while the falling from grace theory indicates that downward mobility is especially stressful. In contrast, the acculturation theory holds that the health implications of social mobility is not due to the movement itself but attributed to the class contexts in which people find themselves. Diagonal Reference Models were used on a sample of 924 individuals who in 1981 graduated from 9(th) grade in the municipality of Luleå, Sweden. Social mobility was operationalized as change in occupational class between age 30 and 42 (measured in 1995 and 2007). The health outcome was functional somatic symptoms at age 42, defined as a clustering self-reported physical symptoms, palpitation and sleeping difficulties during the last 12 months.RESULTS: Overall mobility was not associated with higher levels of functional somatic symptoms compared to being immobile (p = 0.653). After controlling for prior and current class, sex, parental social position, general health, civil status, education and unemployment, the association between downward mobility was borderline significant (p = 0.055) while upward mobility was associated with lower levels of functional somatic symptoms (p = 0.03).CONCLUSION: The current study did not find unanimous support for any of the theories. Nevertheless, it sheds light on the possibility that upward mobility may be beneficial to reduce stress-related health problems in mid-life over and above the exposure to prior and current class, while downward mobility can be of less importance for middle-age health complaints.
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