| 1. |
- Andersson, Maria, et al.
(författare)
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Synthesis and bioanalytical evaluation of morphine-3-O-sulfate and morphine-6-O-sulfate in human urine and plasma using LC-MS/MS
- 2012
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Ingår i: Journal of Separation Science. - : Wiley. - 1615-9306 .- 1615-9314. ; 35:3, s. 367-375
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to synthesize morphine-3-O-sulfate and morphine-6-O-sulfate for use as reference substances, and to determine the sulfate conjugates as possible heroin and morphine metabolites in plasma and urine by a validated LC-MS/MS method. Morphine-6-O-sulfate and morphine-3-O-sulfate were prepared as dihydrates from morphine hydrochloride, in overall yields of 41 and 39% with product purities of >99.5% and >98%, respectively. For bioanalysis, the chromatographic system consisted of a reversed-phase column and gradient elution. The tandem mass spectrometer was operated in the positive electrospray mode using selected reaction monitoring, of transition m/z 366.15 to 286.40. The measuring range was 5500?ng/mL for morphine-3-O-sulfate and 4.5454?ng/mL for morphine-6-O-sulfate in plasma. In urine, the measuring range was 505000?ng/mL for morphine-3-O-sulfate and 45.44544?ng/mL for morphine-6-O-sulfate. The intra-assay and total imprecision (coefficient of variation) was below 11% for both analytes in urine and plasma. Quantifiable levels of morphine-3-O-sulfate in authentic urine and plasma samples were found. Only one authentic urine sample contained a detectable level of morphine-6-O-sulfate, while no detectable morphine-6-O-sulfate was found in plasma samples.
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| 2. |
- Björk, Linnea, et al.
(författare)
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Distinct Heterocyclic Moieties Govern the Selectivity of Thiophene‐Vinylene‐Based Ligands towards Aβ or Tau Pathology in Alzheimer's Disease
- 2023
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Ingår i: European Journal of Organic Chemistry. - : Wiley. - 1434-193X .- 1099-0690. ; 26:41, s. e202300583-
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Tidskriftsartikel (refereegranskat)abstract
- Distinct aggregated proteins are correlated with numerous neurodegenerative diseases and the development of ligands that selectively detect these pathological hallmarks is vital. Recently, the synthesis of thiophene-based optical ligands, denoted bi-thiophene-vinyl-benzothiazoles (bTVBTs), that could be utilized for selective assignment of tau pathology in brain tissue with Alzheimer's disease (AD) pathology, was reported. Herein, we investigate the ability of these ligands to selectively distinguish tau deposits from aggregated amyloid-β (Aβ), the second AD associated pathological hallmark, when replacing the terminal thiophene moiety with other heterocyclic motifs. The selectivity for tau pathology was reduced when introducing specific heterocyclic motifs, verifying that specific molecular interactions between the ligands and the aggregates are necessary for selective detection of tau deposits. In addition, ligands having certain heterocyclic moieties attached to the central thiophene-vinylene building block displayed selectivity to aggregated Aβ pathology. Our findings provide chemical insights for the development of ligands that can distinguish between aggregated proteinaceous species consisting of different proteins and might also aid in creating novel agents for clinical imaging of tau pathology in AD.
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| 3. |
- Butina, Karen, et al.
(författare)
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Optotracing for selective fluorescence-based detection, visualization and quantification of live S. aureus in real-time
- 2020
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Ingår i: npj Biofilms and Microbiomes. - : Nature Research. - 2055-5008. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Methods for bacterial detection are needed to advance the infection research and diagnostics. Based on conformation-sensitive fluorescent tracer molecules, optotracing was recently established for dynamic detection and visualization of structural amyloids and polysaccharides in the biofilm matrix of gram-negative bacteria. Here, we extend the use of optotracing for detection of gram-positive bacteria, focussing on the clinically relevant opportunistic human pathogen Staphylococcus aureus. We identify a donor-acceptor-donor-type optotracer, whose binding-induced fluorescence enables real-time detection, quantification, and visualization of S. aureus in monoculture and when mixed with gram-negative Salmonella Enteritidis. An algorithm-based automated high-throughput screen of 1920 S. aureus transposon mutants recognized the cell envelope as the binding target, which was corroborated by super-resolution microscopy of bacterial cells and spectroscopic analysis of purified cell wall components. The binding event was essentially governed by hydrophobic interactions, which permitted custom-designed tuning of the binding selectivity towards S. aureus versus Enterococcus faecalis by appropriate selection of buffer conditions. Collectively this work demonstrates optotracing as an enabling technology relevant for any field of basic and applied research, where visualization and detection of S. aureus is needed.
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| 4. |
- Butina, Karen, et al.
(författare)
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Structural Properties Dictating Selective Optotracer Detection of Staphylococcus aureus
- 2022
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Ingår i: ChemBioChem (Print). - : Wiley. - 1439-4227 .- 1439-7633. ; 23:11
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Tidskriftsartikel (refereegranskat)abstract
- Optotracers are conformation-sensitive fluorescent tracer molecules that detect peptide- and carbohydrate-based biopolymers. Their binding to bacterial cell walls allows selective detection and visualisation of Staphylococcus aureus (S. aureus). Here, we investigated the structural properties providing optimal detection of S. aureus. We quantified spectral shifts and fluorescence intensity in mixes of bacteria and optotracers, using automatic peak analysis, cross-correlation, and area-under-curve analysis. We found that the length of the conjugated backbone and the number of charged groups, but not their distribution, are important factors for selective detection of S. aureus. The photophysical properties of optotracers were greatly improved by incorporating a donor-acceptor-donor (D-A-D)-type motif in the conjugated backbone. With significantly reduced background and binding-induced on-switch of fluorescence, these optotracers enabled real-time recordings of S. aureus growth. Collectively, this demonstrates that chemical structure and photophysics are key tunable characteristics in the development of optotracers for selective detection of bacterial species.
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| 5. |
- Calvo-Rodriguez, Maria, et al.
(författare)
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In vivo detection of tau fibrils and amyloid beta aggregates with luminescent conjugated oligothiophenes and multiphoton microscopy
- 2019
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Ingår i: Acta neuropathologica communications. - : BMC. - 2051-5960. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- The detection of amyloid beta deposits and neurofibrillary tangles, both hallmarks of Alzheimers disease (AD), is key to understanding the mechanisms underlying these pathologies. Luminescent conjugated oligothiophenes (LCOs) enable fluorescence imaging of these protein aggregates. Using LCOs and multiphoton microscopy, individual tangles and amyloid beta deposits were labeled in vivo and imaged longitudinally in a mouse model of tauopathy and cerebral amyloidosis, respectively. Importantly, LCO HS-84, whose emission falls in the green region of the spectrum, allowed for the first time longitudinal imaging of tangle dynamics following a single intravenous injection. In addition, LCO HS-169, whose emission falls in the red region of the spectrum, successfully labeled amyloid beta deposits, allowing multiplexing with other reporters whose emission falls in the green region of the spectrum. In conclusion, this method can provide a new approach for longitudinal in vivo imaging using multiphoton microscopy of AD pathologies as well as other neurodegenerative diseases associated with protein aggregation in mouse models.
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| 6. |
- Calvo-Rodriguez, Maria, et al.
(författare)
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Real-time imaging of mitochondrial redox reveals increased mitochondrial oxidative stress associated with amyloid ß aggregates in vivo in a mouse model of Alzheimer's disease
- 2024
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Ingår i: Molecular Neurodegeneration. - : BMC. - 1750-1326. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundReactive oxidative stress is a critical player in the amyloid beta (A beta) toxicity that contributes to neurodegeneration in Alzheimer's disease (AD). Damaged mitochondria are one of the main sources of reactive oxygen species and accumulate in A beta plaque-associated dystrophic neurites in the AD brain. Although A beta causes neuronal mitochondria reactive oxidative stress in vitro, this has never been directly observed in vivo in the living mouse brain. Here, we tested for the first time whether A beta plaques and soluble A beta oligomers induce mitochondrial oxidative stress in surrounding neurons in vivo, and whether this neurotoxic effect can be abrogated using mitochondrial-targeted antioxidants.MethodsWe expressed a genetically encoded fluorescent ratiometric mitochondria-targeted reporter of oxidative stress in mouse models of the disease and performed intravital multiphoton microscopy of neuronal mitochondria and A beta plaques.ResultsFor the first time, we demonstrated by direct observation in the living mouse brain exacerbated mitochondrial oxidative stress in neurons after both A beta plaque deposition and direct application of soluble oligomeric A beta onto the brain, and determined the most likely pathological sequence of events leading to oxidative stress in vivo. Oxidative stress could be inhibited by both blocking calcium influx into mitochondria and treating with the mitochondria-targeted antioxidant SS31. Remarkably, the latter ameliorated plaque-associated dystrophic neurites without impacting A beta plaque burden.ConclusionsConsidering these results, combination of mitochondria-targeted compounds with other anti-amyloid beta or anti-tau therapies hold promise as neuroprotective drugs for the prevention and/or treatment of AD.
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| 7. |
- Choong, Ferdinand X., et al.
(författare)
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Stereochemical Identification of Glucans by a Donor-Acceptor-Donor Conjugated Pentamer Enables Multi-Carbohydrate Anatomical Mapping in Plant Tissues
- 2019
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Ingår i: Cellulose. - : Springer Netherlands. - 0969-0239 .- 1572-882X. ; 26:7, s. 4253-4264
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Tidskriftsartikel (refereegranskat)abstract
- Optotracing is a novel method for analytical imaging of carbohydrates in plant and microbial tissues. This optical method applies structure-responsive oligothiophenes as molecular fluorophores emitting unique optical signatures when bound to polysaccharides. Herein, we apply Carbotrace680, a short length anionic oligothiophene with a central heterocyclic benzodithiazole (BTD) motif, to probe for different glucans. The donor-acceptor-donor type electronic structure of Carbotrace680 provides improved spectral properties compared to oligothiophenes due to the possibility of intramolecular charge-transfer transition to the BTD motif. This enables differentiation of glucans based on the glycosidic linkage stereochemistry. Thus -configured starch is readily differentiated from -configured cellulose. The versatility of optotracing is demonstrated by dynamic monitoring of thermo-induced starch remodelling, shown in parallel by spectrophotometry and microscopy of starch granules. Imaging of Carbotrace680 bound to multiple glucans in plant tissues provided direct identification of their physical locations, revealing the spatial relationship between structural (cellulose) and storage (starch) glucans at sub-cellular scale. Our work forms the basis for the development of superior optotracers for sensitive detection of polysaccharides. Our non-destructive method for anatomical mapping of glucans in biomass will serve as an enabling technology for developments towards efficient use of plant-derived materials and biomass.
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| 8. |
- Farhangi, Hadis, et al.
(författare)
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Optimizing growth conditions in vertical farming: enhancing lettuce and basil cultivation through the application of the Taguchi method
- 2023
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the findings of an experimental study that investigated the impact of various environmental factors on the growth of lettuce and basil plants in vertical farms. The study employed the Taguchi method, a statistical design of experiments approach, to efficiently identify the optimal growth conditions for these crops in a hyper-controlled environment. By reducing the time and cost of designing and running experiments, this method allowed for the simultaneous investigation of multiple environmental factors that affect plant growth. A total of 27 treatments were selected using the Taguchi approach, and the signal to noise ratio was calculated to predict the optimal levels of each environmental condition for maximizing basil and lettuce growth parameters. The results showed that most of the parameters, except for EC and relative humidity for certain growth parameters, were interrelated with each other. To validate the results, confirmation tests were conducted based on the predicted optimal parameters. The low error ratio between expected and predicted values (1-3%) confirmed the effectiveness of the Taguchi approach for determining the optimal environmental conditions for plant growth in vertical farms.
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| 9. |
- Faustini, Gaia, et al.
(författare)
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Synapsin III gene silencing redeems alpha-synuclein transgenic mice from Parkinsons disease-like phenotype
- 2022
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Ingår i: Molecular Therapy. - : Cell Press. - 1525-0016 .- 1525-0024. ; 30:4, s. 1465-1483
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Tidskriftsartikel (refereegranskat)abstract
- Fibrillary aggregated alpha-synuclein (alpha-syn) deposition in Lewy bodies (LB) characterizes Parkinsons disease (PD) and is believed to trigger dopaminergic synaptic failure and a retrograde terminal-to-cell body neuronal degeneration. We described that the neuronal phosphoprotein synapsin III (Syn III) cooperates with alpha-syn to regulate dopamine (DA) release and can be found in the insoluble alpha-syn fibrils composing LB. Moreover, we showed that a-syn aggregates deposition, and the associated onset of synaptic deficits and neuronal degeneration occurring following adeno-associated viral vectors-mediated overexpression of human alpha-syn in the nigrostriatal system are hindered in Syn III knock out mice. This supports that Syn III facilitates alpha-syn aggregation. Here, in an interventional experimental design, we found that by inducing the gene silencing of Syn III in human alpha-syn transgenic mice at PD-like stage with advanced alpha-syn aggregation and overt striatal synaptic failure, we could lower alpha-syn aggregates and striatal fibers loss. In parallel, we observed recovery from synaptic vesicles clumping, DA release failure, and motor functions impairment. This supports that Syn III consolidates alpha-syn aggregates, while its downregulation enables their reduction and redeems the PD-like phenotype. Strategies targeting Syn III could thus constitute a therapeutic option for PD.
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| 10. |
- Gomez-Gutierrez, Ruben, et al.
(författare)
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Two structurally defined A & beta; polymorphs promote different pathological changes in susceptible mice
- 2023
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Ingår i: EMBO Reports. - : WILEY. - 1469-221X .- 1469-3178. ; 24:8
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Tidskriftsartikel (refereegranskat)abstract
- Misfolded A & beta; is involved in the progression of Alzheimers disease (AD). However, the role of its polymorphic variants or conformational strains in AD pathogenesis is not fully understood. Here, we study the seeding properties of two structurally defined synthetic misfolded A & beta; strains (termed 2F and 3F) using in vitro and in vivo assays. We show that 2F and 3F strains differ in their biochemical properties, including resistance to proteolysis, binding to strain-specific dyes, and in vitro seeding. Injection of these strains into a transgenic mouse model produces different pathological features, namely different rates of aggregation, formation of different plaque types, tropism to specific brain regions, differential recruitment of A & beta;(40)/A & beta;(42) peptides, and induction of microglial and astroglial responses. Importantly, the aggregates induced by 2F and 3F are structurally different as determined by ssNMR. Our study analyzes the biological properties of purified A & beta; polymorphs that have been characterized at the atomic resolution level and provides relevant information on the pathological significance of misfolded A & beta; strains.
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