| 1. |
- Bakochi, Anahita, et al.
(författare)
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Cerebrospinal fluid proteome maps detect pathogen-specific host response patterns in meningitis
- 2021
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Ingår i: eLife. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Meningitis is a potentially life-threatening infection characterized by the inflammation of the leptomeningeal membranes. Many different viral and bacterial pathogens can cause meningitis, with differences in mortality rates, risk of developing neurological sequelae and treatment options. Here we constructed a compendium of digital cerebrospinal fluid (CSF) proteome maps to define pathogen-specific host response patterns in meningitis. The results revealed a drastic and pathogen-type specific influx of tissue-, cell- and plasma proteins in the CSF, where in particular a large increase of neutrophil derived proteins in the CSF correlated with acute bacterial meningitis. Additionally, both acute bacterial and viral meningitis result in marked reduction of brain-enriched proteins. Generation of a multi-protein LASSO regression model resulted in an 18-protein panel of cell and tissue associated proteins capable of classifying acute bacterial meningitis and viral meningitis. The same protein panel also enabled classification of tick-borne encephalitis, a subgroup of viral meningitis, with high sensitivity and specificity. The work provides insights into pathogen specific host response patterns in CSF from different disease etiologies to support future classification of pathogen-type based on host response patterns in meningitis.
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| 2. |
- Bakochi, Anahita
(författare)
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Proteome-wide analysis of severe bacterial infections. The battle between host and pathogen.
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The pathogenesis of severe infectious diseases is a complex interplay between the host and the pathogen. The development and progression of a disease encompasses a multitude of processes, which balance between host-damage and host-protection. Proteomic analysis provides the necessary tools to interpret the extensive protein networks of host-pathogen interactions underlying the pathogenesis of a particular disease. This thesis focuses on proteome analysis of two blocks; the host-response during disease, as well as the pathogen during colonization and disease. Data-independent acquisition (DIA) mass spectrometry (MS) was utilized to acquire near-to-complete proteome maps of processes involved in the pathogenesis of one severe infectious disease; meningitis, as well as the host-pathogen interaction counterparts of its leading bacterial cause; Streptococcus pneumoniae.High quantitative ability of DIA-MS was used to construct compendiums of digital cerebrospinal fluid (CSF) proteome maps to define the pathogen-specific host response patterns in meningitis. We generated a predictive multiprotein panel of eighteen human proteins with a high sensitivity and specificity, for discrimination of the meningitis-causing pathogens in the CSF during meningitis. The results also showed a large number of neutrophil-associated proteins in the CSF during bacterial meningitis, and these were found to be due to the presence of neutrophil extracellular traps (NETs). The presence of NETs was further confirmed in the CSF in a rat model of pneumococcal meningitis. Treating the animals with DNase resulted in the abolishment of NETs, and led to increased bacterial killing. We further continued to explore the transcriptional landscape and adaptation of S. pneumoniae in human blood plasma by generating a large number of perturbations. A comprehensive pneumococcal proteome repository was constructed to unravel complex protein-protein networks of the bacteria. The results revealed specific regulatory patterns in response to human blood plasma, and pneumococcal transcriptional reorganization regulated by important virulence factors. Furthermore, to describe processes involved in bacterial dissemination in the human nasopharynx, we investigated differences between pneumococcal populations associated with colonization (biofilm bacteria), disease (biofilm-dispersed bacteria) and the conventional broth-grown, planktonic bacteria. The investigated populations showed distinct proteome patterns, especially in regards to metabolic pathways. The virulence of these models was investigated in a murine pneumococcal infection model, where it was showed that virulence of the populations is largely mediated on the investigated pneumococcal serotype. In conclusion, large-scale proteome analyses produced in this thesis generate fundamental knowledge in understanding host-pathogen interactions as a whole. Furthermore, the constructed repositories can be repetitively queried by the scientific community to deepen the understanding in host-pathogen interactions in bacterial infections.
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| 3. |
- Chugh, Deepti, et al.
(författare)
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Alterations in Brain Inflammation, Synaptic Proteins, and Adult Hippocampal Neurogenesis during Epileptogenesis in Mice Lacking Synapsin2.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Synapsins are pre-synaptic vesicle-associated proteins linked to the pathogenesis of epilepsy through genetic association studies in humans. Deletion of synapsins causes an excitatory/inhibitory imbalance, exemplified by the epileptic phenotype of synapsin knockout mice. These mice develop handling-induced tonic-clonic seizures starting at the age of about 3 months. Hence, they provide an opportunity to study epileptogenic alterations in a temporally controlled manner. Here, we evaluated brain inflammation, synaptic protein expression, and adult hippocampal neurogenesis in the epileptogenic (1 and 2 months of age) and tonic-clonic (3.5-4 months) phase of synapsin 2 knockout mice using immunohistochemical and biochemical assays. In the epileptogenic phase, region-specific microglial activation was evident, accompanied by an increase in the chemokine receptor CX3CR1, interleukin-6, and tumor necrosis factor-α, and a decrease in chemokine keratinocyte chemoattractant/ growth-related oncogene. Both post-synaptic density-95 and gephyrin, scaffolding proteins at excitatory and inhibitory synapses, respectively, showed a significant up-regulation primarily in the cortex. Furthermore, we observed an increase in the inhibitory adhesion molecules neuroligin-2 and neurofascin and potassium chloride co-transporter KCC2. Decreased expression of γ-aminobutyric acid receptor-δ subunit and cholecystokinin was also evident. Surprisingly, hippocampal neurogenesis was reduced in the epileptogenic phase. Taken together, we report molecular alterations in brain inflammation and excitatory/inhibitory balance that could serve as potential targets for therapeutics and diagnostic biomarkers. In addition, the regional differences in brain inflammation and synaptic protein expression indicate an epileptogenic zone from where the generalized seizures in synapsin 2 knockout mice may be initiated or spread.
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| 4. |
- Chugh, Deepti, et al.
(författare)
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Brain inflammation induces post-synaptic changes during early synapse formation in adult-born hippocampal neurons.
- 2013
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 250, s. 176-188
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Tidskriftsartikel (refereegranskat)abstract
- An inflammatory reaction in the brain is primarily characterized by activation of parenchymal microglial cells. Microglia regulate several aspects of adult neurogenesis, i.e. the continuous production of new neurons in the adult brain. Hippocampal neurogenesis is thought to be important for memory formation, but its role in brain diseases is not clear. We have previously shown that brain inflammation modulates the functional integration of newly formed hippocampal neurons. Here, we explored whether there is a defined time period during synaptic development when new neurons are susceptible to brain inflammation. Newly formed hippocampal neurons, born in an intact environment in the adult mouse brain, were exposed to lipopolysaccharide (LPS)-induced inflammation during either early or late phases of excitatory and inhibitory synaptogenesis. We used intra-hippocampal injections of GFP-retroviral vector (RV-GFP) to label the new neurons and ipsilateral LPS injection at either 1 or 4weeks post-RV-GFP injection. A single intra-hippocampal LPS injection induced an inflammatory response for at least 3weeks, including an acute transient pro-inflammatory cytokine release as well as a sub-acute and sustained change in microglial morphology. The general cytoarchitecture of the hippocampal dentate gyrus, including granule cell layer (GCL) volume, and astrocytic glial fibrillary acidic protein expression was not different compared to vehicle controls, and no Fluoro-Jade-positive cell death was observed. New neurons encountering this inflammatory environment exhibited no changes in their gross morphology. However, when inflammation occurred during early stages of synapse formation, we found a region-specific increase in the number of thin dendritic spines and post-synaptic density-95 (PSD-95) cluster formation on spines, suggesting an enhanced excitatory synaptic connectivity in the newborn neurons. No changes were observed in the expression of N-cadherin, an adhesion molecule primarily associated with excitatory synapses. At the inhibitory synapses, alterations due to inflammation were also evident during early but not later stages of synaptic development. Gephyrin, an inhibitory scaffolding protein, was down-regulated in the somatic region, while the adhesion molecules neuroligin-2 (NL-2) and neurofascin were increased in the somatic region and/or on the dendrites. The GABAA receptor-α2 subunit (GABAAR-α2) was increased, while pre/peri-synaptic GABA clustering remained unaltered. The disproportional changes in post-synaptic adhesion molecules and GABAA receptor compared to scaffolding protein expression at the inhibitory synapses during brain inflammation are likely to cause an imbalance in GABAergic transmission. These changes were specific for the newborn neurons and were not observed when estimating the overall expression of gephyrin, NL-2, and GABAAR-α2 in the hippocampal GCL. The expression of interleukin-1-type 1 receptor (IL-1R1) on preferentially the somatic region of new neurons, often in close apposition to NL-2 clusters, may indicate a direct interaction between brain inflammation and synaptic proteins on newborn neurons. In summary, this study provides evidence that adult-born hippocampal neurons alter their inhibitory and excitatory synaptic integration when encountering an LPS-induced brain inflammation during the initial stages of synapse formation. Changes at this critical developmental period are likely to interfere with the physiological functions of new neurons within the hippocampus.
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| 5. |
- Lileikyte, Gabriele, et al.
(författare)
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Serum proteome profiles in patients treated with targeted temperature management after out-of-hospital cardiac arrest
- 2023
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Ingår i: Intensive Care Medicine Experimental. - 2197-425X. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Definition of temporal serum proteome profiles after out-of-hospital cardiac arrest may identify biological processes associated with severe hypoxia-ischaemia and reperfusion. It may further explore intervention effects for new mechanistic insights, identify candidate prognostic protein biomarkers and potential therapeutic targets. This pilot study aimed to investigate serum proteome profiles from unconscious patients admitted to hospital after out-of-hospital cardiac arrest according to temperature treatment and neurological outcome.METHODS: Serum samples at 24, 48, and 72 h after cardiac arrest at three centres included in the Target Temperature Management after out-of-hospital cardiac arrest trial underwent data-independent acquisition mass spectrometry analysis (DIA-MS) to find changes in serum protein concentrations associated with neurological outcome at 6-month follow-up and targeted temperature management (TTM) at 33 °C as compared to 36 °C. Neurological outcome was defined according to Cerebral Performance Category (CPC) scale as "good" (CPC 1-2, good cerebral performance or moderate disability) or "poor" (CPC 3-5, severe disability, unresponsive wakefulness syndrome, or death).RESULTS: Of 78 included patients [mean age 66 ± 12 years, 62 (80.0%) male], 37 (47.4%) were randomised to TTM at 36 °C. Six-month outcome was poor in 47 (60.3%) patients. The DIA-MS analysis identified and quantified 403 unique human proteins. Differential protein abundance testing comparing poor to good outcome showed 19 elevated proteins in patients with poor outcome (log 2-fold change (FC) range 0.28-1.17) and 16 reduced proteins (log 2(FC) between - 0.22 and - 0.68), involved in inflammatory/immune responses and apoptotic signalling pathways for poor outcome and proteolysis for good outcome. Analysis according to level of TTM showed a significant protein abundance difference for six proteins [five elevated proteins in TTM 36 °C (log 2(FC) between 0.33 and 0.88), one reduced protein (log 2(FC) - 0.6)] mainly involved in inflammatory/immune responses only at 48 h after cardiac arrest. CONCLUSIONS: Serum proteome profiling revealed an increase in inflammatory/immune responses and apoptosis in patients with poor outcome. In patients with good outcome, an increase in proteolysis was observed, whereas TTM-level only had a modest effect on the proteome profiles. Further validation of the differentially abundant proteins in response to neurological outcome is necessary to validate novel biomarker candidates that may predict prognosis after cardiac arrest.
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| 6. |
- Malmström, Lars, et al.
(författare)
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Quantitative proteogenomics of human pathogens using DIA-MS.
- 2015
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 129, s. 98-107
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Tidskriftsartikel (refereegranskat)abstract
- The increasing number of bacterial genomes in combination with reproducible quantitative proteome measurements provides new opportunities to explore how genetic differences modulate proteome composition and virulence. It is challenging to combine genome and proteome data as the underlying genome influences the proteome. We present a strategy to facilitate the integration of genome data from several genetically similar bacterial strains with data-independent analysis mass spectrometry (DIA-MS) for rapid interrogation of the combined data sets. The strategy relies on the construction of a composite genome combining all genetic data in a compact format, which can accommodate the fusion with quantitative peptide and protein information determined via DIA-MS. We demonstrate the method by combining data sets from whole genome sequencing, shotgun MS and DIA-MS from 34 clinical isolates of Streptococcus pyogenes. The data structure allows for fast exploration of the data showing that undetected proteins are on average more amenable to amino acid substitution than expressed proteins. We identified several significantly differentially expressed proteins between invasive and non-invasive strains. The work underlines how integration of whole genome sequencing with accurately quantified proteomes can further advance the interpretation of the relationship between genomes, proteomes and virulence.
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| 7. |
- Mohanty, Tirthankar, et al.
(författare)
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Neutrophil extracellular traps in the central nervous system hinder bacterial clearance during pneumococcal meningitis
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 1667-1667
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils are crucial mediators of host defense that are recruited to the central nervous system (CNS) in large numbers during acute bacterial meningitis caused by Streptococcus pneumoniae. Neutrophils release neutrophil extracellular traps (NETs) during infections to trap and kill bacteria. Intact NETs are fibrous structures composed of decondensed DNA and neutrophil-derived antimicrobial proteins. Here we show NETs in the cerebrospinal fluid (CSF) of patients with pneumococcal meningitis, and their absence in other forms of meningitis with neutrophil influx into the CSF caused by viruses, Borrelia and subarachnoid hemorrhage. In a rat model of meningitis, a clinical strain of pneumococci induced NET formation in the CSF. Disrupting NETs using DNase I significantly reduces bacterial load, demonstrating that NETs contribute to pneumococcal meningitis pathogenesis in vivo. We conclude that NETs in the CNS reduce bacterial clearance and degrading NETs using DNase I may have significant therapeutic implications.
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| 8. |
- Scott, Aaron M., et al.
(författare)
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Population scale proteomics enables adaptive digital twin modelling in sepsis
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Sepsis is one of the leading causes of mortality in the world. Currently, the heterogeneity of sepsis makes it challenging to determine the molecular mechanisms that define the syndrome. Here, we leverage population scale proteomics to analyze a well-defined cohort of 1364 blood samples taken at time-of-admission to the emergency department from patients suspected of sepsis. We identified panels of proteins using explainable artificial intelligence that predict clinical outcomes and applied these panels to reduce high-dimensional proteomics data to a low-dimensional interpretable latent space (ILS). Using the ILS, we constructed an adaptive digital twin model that accurately predicted organ dysfunction, mortality, and early-mortality-risk patients using only data available at time-of-admission. In addition to being highly effective for investigating sepsis, this approach supports the flexible incorporation of new data and can generalize to other diseases to aid in translational research and the development of precision medicine.Competing Interest StatementThe authors have declared no competing interest.Funding StatementL.M. is funded by the Swedish Research Council (grant number VR-2020-02419), the Wallenberg foundation (grant number 2016.0023) and Alfred Österlunds Foundation. J.M. is a Wallenberg academy fellow (KAW 2017.0271) and is also funded by the Swedish Research Council (Vetenskapsrådet, VR) (2019-01646 and 2018-05795), the Wallenberg foundation (KAW2016.0023, KAW2019.0353 and KAW2020.0299), and Alfred Österlunds Foundation. E.M. is funded by Wenner-Gren Foundation (FT2020-0003), the Crafoord Foundation, and the Swedish Society of Medicine (SLS-985287). F.K. is funded by Region Skåne ALF project and the Crafoord Foundation. A.L. is funded by the Swedish Research Council VR 2023-02707 and Region Skåne ALF project 2022-0146.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:Ethical approval for the study was obtained from the Swedish National Ethics Committee (file numbers 2022-01454-01, 2014/741 and 2016/271).I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesData produced in the present study are available upon reasonable request to the authors
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