| 1. |
- Alvarado, Gerardo, et al.
(författare)
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Heme-induced contractile dysfunction in Human cardiomyocytes caused by oxidant damage to thick filament proteins.
- 2015
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Ingår i: Free Radical Biology & Medicine. - : Elsevier BV. - 0891-5849. ; 89:sep 23, s. 248-262
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Tidskriftsartikel (refereegranskat)abstract
- Intracellular free heme predisposes to oxidant-mediated tissue damage. We hypothesized that free heme causes alterations in myocardial contractility via disturbed structure and/or regulation of the contractile proteins. Isometric force production and its Ca(2+)-sensitivity (pCa50) were monitored in permeabilized human ventricular cardiomyocytes. Heme exposure altered cardiomyocyte morphology and evoked robust decreases in Ca(2+)-activated maximal active force (Fo) while increasing Ca(2+)-independent passive force (Fpassive). Heme treatments, either alone or in combination with H2O2, did not affect pCa50. The increase in Fpassive started at 3µM heme exposure and could be partially reversed by the antioxidant dithiothreitol. Protein sulfhydryl (SH) groups of thick myofilament content decreased and sulfenic acid formation increased after treatment with heme. Partial restoration in the SH group content was observed in a protein running at 140kDa after treatment with dithiothreitol, but not in other proteins, such as filamin C, myosin heavy chain, cardiac myosin binding protein C, and α-actinin. Importantly, binding of heme to hemopexin or alpha-1-microglobulin prevented its effects on cardiomyocyte contractility, suggesting an allosteric effect. In line with this, free heme directly bound to myosin light chain 1 in human cardiomyocytes. Our observations suggest that free heme modifies cardiac contractile proteins via posttranslational protein modifications and via binding to myosin light chain 1, leading to severe contractile dysfunction. This may contribute to systolic and diastolic cardiac dysfunctions in hemolytic diseases, heart failure, and myocardial ischemia-reperfusion injury.
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| 2. |
- Alvarado, Gerardo, et al.
(författare)
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Heme-induced oxidation of cysteine groups of myofilament proteins leads to contractile dysfunction of permeabilized human skeletal muscle fibres
- 2020
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 21:21
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Tidskriftsartikel (refereegranskat)abstract
- Background: Heme released from red blood cells targets a number of cell components including the cytoskeleton. The purpose of the present study was to determine the impact of free heme (20–300 µM) on human skeletal muscle fibres made available during orthopedic surgery. Methods: Isometric force production and oxidative protein modifications were monitored in permeabilized skeletal muscle fibre segments. Results: A single heme exposure (20 µM) to muscle fibres decreased Ca2+-activated maximal (active) force (Fo) by about 50% and evoked an approximately 3-fold increase in Ca2+-independent (passive) force (Fpassive). Oxidation of sulfhydryl (SH) groups was detected in structural proteins (e.g., nebulin, α-actinin, meromyosin 2) and in contractile proteins (e.g., myosin heavy chain and myosin-binding protein C) as well as in titin in the presence of 300 µM heme. This SH oxidation was not reversed by dithiothreitol (50 mM). Sulfenic acid (SOH) formation was also detected in the structural proteins (nebulin, α-actinin, meromyosin). Heme effects on SH oxidation and SOH formation were prevented by hemopexin (Hpx) and α1-microglobulin (A1M). Conclusions: These data suggest that free heme has a significant impact on human skeletal muscle fibres, whereby oxidative alterations in structural and contractile proteins limit contractile function. This may explain and or contribute to the weakness and increase of skeletal muscle stiffness in chronic heart failure, rhabdomyolysis, and other hemolytic diseases. Therefore, therapeutic use of Hpx and A1M supplementation might be effective in preventing heme-induced skeletal muscle alterations.
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| 3. |
- Fragoulis, George E., et al.
(författare)
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2022 EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in adults with autoimmune inflammatory rheumatic diseases
- 2023
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 82:6, s. 742-753
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To develop EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in patients with autoimmune inflammatory rheumatic diseases (AIIRD). Methods: An international Task Force (TF) (22 members/15 countries) formulated recommendations, supported by systematic literature review findings. Level of evidence and grade of recommendation were assigned for each recommendation. Level of agreement was provided anonymously by each TF member. Results: Four overarching principles (OAP) and eight recommendations were developed. The OAPs highlight the need for infections to be discussed with patients and with other medical specialties, in accordance with national regulations. In addition to biologic/targeted synthetic disease-modifying antirheumatic drugs (DMARDs) for which screening for latent tuberculosis (TB) should be performed, screening could be considered also before conventional synthetic DMARDs, glucocorticoids and immunosuppressants. Interferon gamma release assay should be preferred over tuberculin skin test, where available. Hepatitis B (HBV) antiviral treatment should be guided by HBV status defined prior to starting antirheumatic drugs. All patients positive for hepatitis-C-RNA should be referred for antiviral treatment. Also, patients who are non-immune to varicella zoster virus should be informed about the availability of postexposure prophylaxis should they have contact with this pathogen. Prophylaxis against Pneumocystis jirovecii seems to be beneficial in patients treated with daily doses >15-30 mg of prednisolone or equivalent for >2-4 weeks. Conclusions: These recommendations provide guidance on the screening and prevention of chronic and opportunistic infections. Their adoption in clinical practice is recommended to standardise and optimise care to reduce the burden of opportunistic infections in people living with AIIRD.
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| 4. |
- Kindenberg, Björn, et al.
(författare)
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Vilken term är bäst?
- 2017
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Ingår i: Lisetten. - 1101-5128. ; :1, s. 31-31
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- I Lisetten nr 2/2016 diskuterar forskare i Nätverket för translanguaging en svensk motsvarighet till termen translanguaging och för som förslag fram "transspråkande". Artikeln är också en replik på tidigare inlägg i en översättningsdebatt som förts i Lisetten (nr 4/2015 och nr 1/2016), en spännande och belysande serie artiklar som gett en fördjupad diskussion om innebörden av begreppet translanguaging. Artikeln från Nätverket för translanguaging fördjupar resonemangen än mer, men landar, menar vi, i ett olyckligt ordval i och med beteckningen transspråkande.
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| 5. |
- Kjær, Kasper S., et al.
(författare)
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Finding intersections between electronic excited state potential energy surfaces with simultaneous ultrafast X-ray scattering and spectroscopy
- 2019
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Ingår i: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 10:22, s. 5749-5760
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Tidskriftsartikel (refereegranskat)abstract
- Light-driven molecular reactions are dictated by the excited state potential energy landscape, depending critically on the location of conical intersections and intersystem crossing points between potential surfaces where non-adiabatic effects govern transition probabilities between distinct electronic states. While ultrafast studies have provided significant insight into electronic excited state reaction dynamics, experimental approaches for identifying and characterizing intersections and seams between electronic states remain highly system dependent. Here we show that for 3d transition metal systems simultaneously recorded X-ray diffuse scattering and X-ray emission spectroscopy at sub-70 femtosecond time-resolution provide a solid experimental foundation for determining the mechanistic details of excited state reactions. In modeling the mechanistic information retrieved from such experiments, it becomes possible to identify the dominant trajectory followed during the excited state cascade and to determine the relevant loci of intersections between states. We illustrate our approach by explicitly mapping parts of the potential energy landscape dictating the light driven low-to-high spin-state transition (spin crossover) of [Fe(2,2′-bipyridine)3]2+, where the strongly coupled nuclear and electronic dynamics have been a source of interest and controversy. We anticipate that simultaneous X-ray diffuse scattering and X-ray emission spectroscopy will provide a valuable approach for mapping the reactive trajectories of light-triggered molecular systems involving 3d transition metals.
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| 6. |
- Kjær, Kasper S., et al.
(författare)
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Solvent control of charge transfer excited state relaxation pathways in [Fe(2,2′-bipyridine)(CN)4]2-
- 2018
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 20:6, s. 4238-4249
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Tidskriftsartikel (refereegranskat)abstract
- The excited state dynamics of solvated [Fe(bpy)(CN)4]2-, where bpy = 2,2′-bipyridine, show significant sensitivity to the solvent Lewis acidity. Using a combination of optical absorption and X-ray emission transient spectroscopies, we have previously shown that the metal to ligand charge transfer (MLCT) excited state of [Fe(bpy)(CN)4]2- has a 19 picosecond lifetime and no discernable contribution from metal centered (MC) states in weak Lewis acid solvents, such as dimethyl sulfoxide and acetonitrile.1,2 In the present work, we use the same combination of spectroscopic techniques to measure the MLCT excited state relaxation dynamics of [Fe(bpy)(CN)4]2- in water, a strong Lewis acid solvent. The charge-transfer excited state is now found to decay in less than 100 femtoseconds, forming a quasi-stable metal centered excited state with a 13 picosecond lifetime. We find that this MC excited state has triplet (3MC) character, unlike other reported six-coordinate Fe(ii)-centered coordination compounds, which form MC quintet (5MC) states. The solvent dependent changes in excited state non-radiative relaxation for [Fe(bpy)(CN)4]2- allows us to infer the influence of the solvent on the electronic structure of the complex. Furthermore, the robust characterization of the dynamics and optical spectral signatures of the isolated 3MC intermediate provides a strong foundation for identifying 3MC intermediates in the electronic excited state relaxation mechanisms of similar Fe-centered systems being developed for solar applications.
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| 7. |
- Lindroth, Eva, et al.
(författare)
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QED effects in Cu-like Pb recombination resonances near threshold
- 2001
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Ingår i: Physical Review Letters. - 0031-9007. ; 86:22, s. 5027-5030
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Tidskriftsartikel (refereegranskat)abstract
- In an electron-ion recombination study with Pb53+ dielectronic recombination resonances are found for as low as similar to 10(-3)-10(-4) eV relative energy. The resonances have been calculated by relativistic many-body perturbation theory and through comparison with experiment the Pb53+(4p(1/2)-4s(1/2)) energy splitting of similar to 118 eV is determined with an accuracy comparable to the position of the first few resonances, i.e., similar to 10(-3) eV. Such a precision provides a test of QED in a many-body environment at a level which can still not be reached in calculations.
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| 8. |
- Malmström, Johan, et al.
(författare)
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Transforming growth factor-beta 1 specifically induce proteins involved in the myofibroblast contractile apparatus
- 2004
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Ingår i: Molecular & Cellular Proteomics. - 1535-9484. ; 3:5, s. 466-477
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor-beta(1) (TGF-beta(1)) induces alpha-smooth muscle actin (alpha-SMA) and collagen synthesis in fibroblast both in vivo and in vitro and plays a significant role in tissue repair and the development of fibrosis. During these processes the fibroblasts differentiate into activated fibroblasts (so called myofibroblasts), characterized by increased alpha-SMA expression. Because TGF-beta(1) is considered the main inducer of the myofibroblast phenotype and cytoskeletal changes accompany this differentiation, the main objective of this investigation was to study how TGF-beta(1) alters protein expression of cytoskeletal-associated proteins. Metabolic labeling of cell cultures by [(35)S]methionine, followed by protein separation on two-dimensional gel electrophoresis, displayed approximately 2500 proteins in the pI interval of 3-10. Treatment of TGF-beta(1) led to specific spot pattern changes that were identified by mass spectrometry and represent specific induction of several members of the contractile apparatus such as calgizzarin, cofilin, and profilin. These proteins have not previously been shown to be regulated by TGF-beta(1), and the functional role of these proteins is to participate in the depolymerization and stabilization of the microfilaments. These results show that TGF-beta(1) induces not only alpha-SMA but a whole set of actin-associated proteins that may contribute to the increased contractile properties of the myofibroblast. These proteins accompany the induced expression of alpha-SMA and may participate in the formation of stress fibers, cell contractility, and cell spreading characterizing the myofibroblasts phenotype.
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| 9. |
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| 10. |
- Máthé, I., et al.
(författare)
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Investigation of mineral water springs of Miercurea Ciuc (Csíkszereda) region (Romania) with cultivation-dependent microbiological methods
- 2010
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Ingår i: Acta Microbiologica et Immunologica Hungarica. - 1217-8950 .- 1588-2640. ; 57:2, s. 109-122
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Tidskriftsartikel (refereegranskat)abstract
- Water samples of ten mineral water springs at Miercurea Ciuc (Csíkszereda) region (Romania) were examined during 2005-2006 using cultivation-dependent microbiological methods. The results of standard hygienic bacteriological tests showed that the Hargita Spring had perfect and five other springs had microbiologically acceptable water quality (Zsögöd-, Nagy-borvíz-, Taploca-, Szentegyháza- and Lobogó springs). The water of Borsáros Spring was exceptionable (high germ count, presence of Enterococcus spp.).Both standard bacteriological and molecular microbiological methods indicated that the microbiological water quality of the Szeltersz-, Nádasszék- and Délo springs was not acceptable. Bad water quality resulted from inadequate spring catchment and hygiene (low yield, lack of runoff, negligent usage of the springs, horse manure around the spring).The 16S rRNA gene-based identification of strains isolated on standard meat-peptone medium resulted in the detection of typical aquatic organisms such as Shewanella baltica, Aeromonas spp., Pseudomonas veronii, Psychrobacter sp,. Acinetobacter spp. and allochthonous microbes, like Nocardia, Streptomyces, Bacillus, Microbacterium , and Arthrobacter strains indicating the impact of soil. Other allochthonous microbes, such as Staphylococcus spp., Micrococcus sp., Lactococcus sp., Clostridium butyricum, Yersinia spp., Aerococcus sp., may have originated from animal/human sources. © 2010 Akadémiai Kiadó, Budapest.
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| 11. |
- Mendonça, Clarissa Ferolla, et al.
(författare)
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Proteomic signatures of brain regions affected by tau pathology in early and late stages of Alzheimer's disease
- 2019
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 130
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Tidskriftsartikel (refereegranskat)abstract
- Background: Alzheimer's disease (AD) is the most common neurodegenerative disorder. Depositions of amyloid β peptide (Aβ) and tau protein are among the major pathological hallmarks of AD. Aβ and tau burden follows predictable spatial patterns during the progression of AD. Nevertheless, it remains obscure why certain brain regions are more vulnerable than others; to investigate this and dysregulated pathways during AD progression, a mass spectrometry-based proteomics study was performed. Methods: In total 103 tissue samples from regions early (entorhinal and parahippocampal cortices - medial temporal lobe (MTL)) and late affected (temporal and frontal cortices - neocortex) by tau pathology were subjected to label-free quantitative proteomics analysis. Results: Considering dysregulated proteins during AD progression, the majority (625 out of 737 proteins) was region specific, while some proteins were shared between regions (101 proteins altered in two areas and 11 proteins altered in three areas). Analogously, many dysregulated pathways during disease progression were exclusive to certain regions, but a few pathways altered in two or more areas. Changes in protein expression indicate that synapse loss occurred in all analyzed regions, while translation dysregulation was preponderant in entorhinal, parahippocampal and frontal cortices. Oxidative phosphorylation impairment was prominent in MTL. Differential proteomic analysis of brain areas in health state (controls) showed higher metabolism and increased expression of AD-related proteins in the MTL compared to the neocortex. In addition, several proteins that differentiate brain regions in control tissue were dysregulated in AD. Conclusions: This work provides the comparison of proteomic changes in brain regions affected by tau pathology at different stages of AD. Although we identified commonly regulated proteins and pathways during disease advancement, we found that the dysregulated processes are predominantly region specific. In addition, a distinct proteomic signature was found between MTL and neocortex in healthy subjects that might be related to AD vulnerability. These findings highlight the need for investigating AD's cascade of events throughout the whole brain and studies spanning more brain areas are required to better understand AD etiology and region vulnerability to disease.
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| 12. |
- Pascual, Unai, et al.
(författare)
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Valuing nature's contributions to people : the IPBES approach
- 2017
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Ingår i: Current Opinion in Environmental Sustainability. - : Elsevier BV. - 1877-3435. ; 26-27, s. 7-16
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Forskningsöversikt (refereegranskat)abstract
- Nature is perceived and valued in starkly different and often conflicting ways. This paper presents the rationale for the inclusive valuation of nature's contributions to people (NCP) in decision making, as well as broad methodological steps for doing so. While developed within the context of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), this approach is more widely applicable to initiatives at the knowledge–policy interface, which require a pluralistic approach to recognizing the diversity of values. We argue that transformative practices aiming at sustainable futures would benefit from embracing such diversity, which require recognizing and addressing power relationships across stakeholder groups that hold different values on human nature-relations and NCP.
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| 13. |
- Tatsuno, Hideyuki, et al.
(författare)
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Hot Branching Dynamics in a Light-Harvesting Iron Carbene Complex Revealed by Ultrafast X-ray Emission Spectroscopy
- 2020
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Ingår i: Angewandte Chemie - International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 59:1, s. 364-372
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Tidskriftsartikel (refereegranskat)abstract
- Iron N-heterocyclic carbene (NHC) complexes have received a great deal of attention recently because of their growing potential as light sensitizers or photocatalysts. We present a sub-ps X-ray spectroscopy study of an FeIINHC complex that identifies and quantifies the states involved in the deactivation cascade after light absorption. Excited molecules relax back to the ground state along two pathways: After population of a hot 3MLCT state, from the initially excited 1MLCT state, 30 % of the molecules undergo ultrafast (150 fs) relaxation to the 3MC state, in competition with vibrational relaxation and cooling to the relaxed 3MLCT state. The relaxed 3MLCT state then decays much more slowly (7.6 ps) to the 3MC state. The 3MC state is rapidly (2.2 ps) deactivated to the ground state. The 5MC state is not involved in the deactivation pathway. The ultrafast partial deactivation of the 3MLCT state constitutes a loss channel from the point of view of photochemical efficiency and highlights the necessity to screen transition-metal complexes for similar ultrafast decays to optimize photochemical performance.
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| 14. |
- Velásquez, Erika, et al.
(författare)
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Topological Dissection of Proteomic Changes Linked to the Limbic Stage of Alzheimer’s Disease
- 2021
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer’s disease (AD) is a neurodegenerative disorder and the most common cause of dementia worldwide. In AD, neurodegeneration spreads throughout different areas of the central nervous system (CNS) in a gradual and predictable pattern, causing progressive memory decline and cognitive impairment. Deposition of neurofibrillary tangles (NFTs) in specific CNS regions correlates with the severity of AD and constitutes the basis for disease classification into different Braak stages (I-VI). Early clinical symptoms are typically associated with stages III-IV (i.e., limbic stages) when the involvement of the hippocampus begins. Histopathological changes in AD have been linked to brain proteome alterations, including aberrant posttranslational modifications (PTMs) such as the hyperphosphorylation of Tau. Most proteomic studies to date have focused on AD progression across different stages of the disease, by targeting one specific brain area at a time. However, in AD vulnerable regions, stage-specific proteomic alterations, including changes in PTM status occur in parallel and remain poorly characterized. Here, we conducted proteomic, phosphoproteomic, and acetylomic analyses of human postmortem tissue samples from AD (Braak stage III-IV, n=11) and control brains (n=12), covering all anatomical areas affected during the limbic stage of the disease (total hippocampus, CA1, entorhinal and perirhinal cortices). Overall, ~6000 proteins, ~9000 unique phosphopeptides and 221 acetylated peptides were accurately quantified across all tissues. Our results reveal significant proteome changes in AD brains compared to controls. Among others, we have observed the dysregulation of pathways related to the adaptive and innate immune responses, including several altered antimicrobial peptides (AMPs). Notably, some of these changes were restricted to specific anatomical areas, while others altered according to disease progression across the regions studied. Our data highlights the molecular heterogeneity of AD and the relevance of neuroinflammation as a major player in AD pathology. Data are available via ProteomeXchange with identifier PXD027173.
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