| 1. |
- Basic, Vladimir T., 1982-, et al.
(författare)
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Chronic cigarette smoke exposureimpairs skeletal muscle regenerative capacity in murineCOPD/emphysema model.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Cigarette smoke (CS) is a well established risk factor in the development of COPD and irreversible airflow limitation. In contrast, the extent to which CS exposure contributes to development of peripheral skeletal muscle dysfunction and wasting remains largely unknown. Decline in skeletal muscle regenerative capacity has been previously reported in COPD patients.Methods: To investigate effects of chronic CS exposure on skeletal muscle regenerative capacity, 129/SvJ mice were exposed to CS for 6 months. The expression levels of myogenin, Jarid2, Znf496, Notch1, Pax7, Fgf1 and Myh3, which are known to regulate skeletal muscle myogenesis, were studied. Additionally, number of fibers with central nuclei, myonuclei number and mean fiber cross-sectional area were assessed.Results: Compared to controls, skeletal muscles from CS-exposed mice exhibited significantly decreased expression of Jarid2, coupled with enhanced expression of Znf496, Notch1, Pax7, Fgf1 and Myh3. Expression of myogenin, a marker of terminally differentiated myofibers, was reduced. Furthermore, reduced muscle fiber crosssectional area, increased number of fibers with central nuclei and reduced myonuclei number were also observed in CS-exposed animals.Conclusions: Taken together, current results provide evidence linking chronic CS exposure and an ongoing damage/repair process as well as impaired regenerative capacity in skeletal muscles of CS-exposed mice.
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| 2. |
- Basic, Vladimir T., et al.
(författare)
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Cigarette smoke exposure up-regulates Ubiquitin specific protease 19 in murine skeletal muscles as an adaptive response to prolonged ER stress
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Enhanced protein degradation via ubiquitin proteolytic system (UPS) was demonstrated to play an important role in the pathogenesis of cachexia syndrome and muscle wasting in patients with COPD and animal models of the disease. The role of cigarette smoke (CS) exposure in eliciting these abnormalities remains largely unknown. Usp19 is a member of UPS suggested to be involved in progressive muscle wasting in different catabolic conditions. However, factors regulating Usp19 expression, activity and correlation/s with CS-induced muscle atrophy remainunclear.Methods: To address these questions, 129 SvJ mice were exposed to cigarette smoke for 6 months and the gastrocnemius muscles were collected. Expression levels of Usp19 as well as pivotal mediators of ER stress response have been studied using PCR, qPCR, western blot and immunofluorescence. Factors regulating muscle Usp19 expression were studied using in-silico analysis of Usp19 promoter as well as by stimulating C2C12 myocytes with different inducers of ER stress including hypoxia, TNF and tunicamycin. Finally, Usp19 expression was depleted in C2C12 myocytes using specific Usp19 siRNA quadriplex and the expression of pivotal myogenic regulators were analyzed.Results: Usp19 mRNA expression was enhanced in skeletal muscles of CS-exposed mice. Concurrently, ER stress-associated Caspase 12 and Caspase 3 were activated in the CS-exposed group. Analysis of Usp19 promoter sequence revealed binding sites for ER stress response transcription factors such as HSF, STRE1 and AML1-α. Exposure of C2C12 myocytes to tunicamycin but not hypoxia elevated expression levels of Usp19. TNFstimulation elevated Usp19 protein expression but inhibited its RNA transcription in a dose- and time-dependent manner. Finally, Usp19 overexpression in tunicamycin-treated myocytes was accompanied by reduced expression of myosin heavy chain and tropomyosin and their levels were increased after knocking down Usp19 in C2C12 myocytes.Conclusions: In summary, our data demonstrated elevated expression of Usp19 in skeletal muscles of CS-exposed 129 SvJ mice. Moreover, Usp19 overexpression was associated with muscle adaptations to ER stress and suppression of myogenesis. Taken together; our results might provide further insight into molecular mechanisms underlying development and progression of skeletal muscle abnormalities in response to chronic cigarette smoke exposure.
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| 3. |
- Basic, Vladimir T., 1982-, et al.
(författare)
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TNF stimulation induces VHL overexpression and impairs angiogenic potential in skeletal muscle myocytes
- 2014
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Ingår i: International Journal of Molecular Medicine. - : Spandidos Publications. - 1107-3756 .- 1791-244X. ; 34:1, s. 228-236
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Tidskriftsartikel (refereegranskat)abstract
- Decreased skeletal muscle capillarization is considered to significantly contribute to the development of pulmonary cachexia syndrome (PCS) and progressive muscle wasting in several chronic inflammatory diseases, including chronic obstructive pulmonary disease (COPD). It is unclear to which extent the concurrent presence of systemic inflammation contributes to decreased skeletal muscle capillarization under these conditions. The present study was designed to examine in vitro the effects of the pro-inflammatory cytokine, tumor necrosis factor (TNF), on the regulation of hypoxia-angiogenesis signal transduction and capillarization in skeletal muscles. For this purpose, fully differentiated C2C12 skeletal muscle myocytes were stimulated with TNF and maintained under normoxic or hypoxic conditions. The expression levels of the putative elements of the hypoxia-angiogenesis signaling cascade were examined using qPCR, western blot analysis and immunofluorescence. Under normoxic conditinos, TNF stimulation increased the protein expression of anti-angiogenic von-Hippel Lindau (VHL), prolyl hydroxylase (PHD)2 and ubiquitin conjugating enzyme 2D1 (Ube2D1), as well as the total ubiquitin content in the skeletal muscle myocytes. By contrast, the expression levels of hypoxia-inducible factor 1‑α (HIF1-α) and those of its transcriptional targets, vascular endothelial growth factor (VEGF)A and glucose transporter 1 (Glut1), were markedly reduced. In addition, hypoxia increased the expression of the VHL transcript and further elevated the VHL protein expression levels in C2C12 myocytes following TNF stimulation. Consequently, an impaired angiogenic potential was observed in the TNF-stimulated myocytes during hypoxia. In conclusion, TNF increases VHL expression and disturbs hypoxia-angiogenesis signal transduction in skeletal muscle myocytes. The current findings provide a mechanism linking systemic inflammation and impaired angiogenesis in skeletal muscle. This is particularly relevant to further understanding the mechanisms mediating muscle wasting and cachexia in patients with chronic inflammatory diseases, such as COPD.
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| 4. |
- Bendtsen, Katja Maria, et al.
(författare)
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Particle characterization and toxicity in C57BL/6 mice following instillation of five different diesel exhaust particles designed to differ in physicochemical properties
- 2020
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Ingår i: Particle and Fibre Toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Diesel exhaust is carcinogenic and exposure to diesel particles cause health effects. We investigated the toxicity of diesel exhaust particles designed to have varying physicochemical properties in order to attribute health effects to specific particle characteristics. Particles from three fuel types were compared at 13% engine intake O2 concentration: MK1 ultra low sulfur diesel (DEP13) and the two renewable diesel fuels hydrotreated vegetable oil (HVO13) and rapeseed methyl ester (RME13). Additionally, diesel particles from MK1 ultra low sulfur diesel were generated at 9.7% (DEP9.7) and 17% (DEP17) intake O2 concentration. We evaluated physicochemical properties and histopathological, inflammatory and genotoxic responses on day 1, 28, and 90 after single intratracheal instillation in mice compared to reference diesel particles and carbon black. RESULTS: Moderate variations were seen in physical properties for the five particles: primary particle diameter: 15-22 nm, specific surface area: 152-222 m2/g, and count median mobility diameter: 55-103 nm. Larger differences were found in chemical composition: organic carbon/total carbon ratio (0.12-0.60), polycyclic aromatic hydrocarbon content (1-27 μg/mg) and acid-extractable metal content (0.9-16 μg/mg). Intratracheal exposure to all five particles induced similar toxicological responses, with different potency. Lung particle retention was observed in DEP13 and HVO13 exposed mice on day 28 post-exposure, with less retention for the other fuel types. RME exposure induced limited response whereas the remaining particles induced dose-dependent inflammation and acute phase response on day 1. DEP13 induced acute phase response on day 28 and inflammation on day 90. DNA strand break levels were not increased as compared to vehicle, but were increased in lung and liver compared to blank filter extraction control. Neutrophil influx on day 1 correlated best with estimated deposited surface area, but also with elemental carbon, organic carbon and PAHs. DNA strand break levels in lung on day 28 and in liver on day 90 correlated with acellular particle-induced ROS. CONCLUSIONS: We studied diesel exhaust particles designed to differ in physicochemical properties. Our study highlights specific surface area, elemental carbon content, PAHs and ROS-generating potential as physicochemical predictors of diesel particle toxicity.
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| 5. |
- Eriksen, Jonas Borregaard, et al.
(författare)
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'Stirred not Shaken!' Comparing Agitation Methods for Permeability Studies Using a Novel Type of 96-Well Sandwich-Plates
- 2022
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Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier. - 0022-3549 .- 1520-6017. ; 111:1, s. 32-40
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Tidskriftsartikel (refereegranskat)abstract
- In order to achieve a high sample throughput, permeation experiments are often carried out using 96-well sandwich plates. Even though agitation is regarded as important, permeation studies in 96-well format are often carried out without agitation since orbital shaking, the most common agitation method for 96-well plates, has been reported to create difficulties (e.g., well-to-well cross-talk), and high cost and low availability limits the use of other agitation techniques (e.g., magnetic stirring). This study investigates how orbital shaking and magnetic stirring affect the apparent permeability of model compounds with different water-solubilities (methylene blue, carbamazepine, and albendazole) using a novel 96-well sandwich plate comprising a cellulose-hydrate membrane (PermeaPlain (R) plate). Orbital shaking was found less efficient than magnetic stirring in terms of homogeneously distributing a small volume of dye within the donor compartment. Furthermore, in terms of achieving maximum trans-barrier flux, magnetic stirring was found a more effective agitation method than orbital shaking. Obviously, with orbital shaking the medium in the bottom compartment of the sandwich plates never was mixed in-phase. The impact of insufficient mixing on permeation was found strongest with the most lipophilic compound, which correlates with literature reports that the contribution of the unstirred water layer towards the overall resistance of the barrier is most expressed in case of lipophilic drugs. Finally, it was tested how different liquid volumes in the bottom compartment of the plates affect the well-to-well cross-talk during permeation experiments under orbital shaking. This study revealed that 250-300 mu L should be used in the bottom compartment of the sandwich plates to reduce well-to-well cross-talk when using orbital shaking for agitation. (C) 2021 Published by Elsevier Inc. on behalf of American Pharmacists Association.
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| 6. |
- Ferdousi, Hosne Ara, et al.
(författare)
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Clinical characteristics of school children with birch and/or grass pollen hay-fever (The PAT-Study)
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: To describe the clinical characteristics of school children with hay-fever based on baseline data from the PAT-Study.Material: Two hundred and five children, 6-15 years, mean 10.7 years, with birch and or grass pollen hay-fever, without known asthma were recruited by six pediatric allergy centers in Northern and Central Europe.Methods: Bronchial hyperresponsiveness (BHR) to methacholine tested by methacholine bronchial provocation test (MBPT) expressed in PC20 was registered during the birch and grass pollen seasons. During the winter symptoms of conjunctivitis, rhinitis and asthma were graded by visual analogue scale (VAS), conjunctival provocation test with birch and or timothy pollen extracts, skin tests with a panel of allergen extracts and MBPT were done and a questionnaire was filled in. Differences of p <0.01 level or less were considered significant.Results: Despite the children were included because of seasonal hay-fever without known asthma, 42/205 children (21 %) got doctor diagnosed asthma (DDA) after the first season. During the three seasons, between 60 and 73 % of the children had a PC20 to methacholine ≤ 8 mg/ml, about 30 % to ≤ 2 mg/ml and 7-10% even to ≤ 0.5 mg/ml. Most children had both rhinitis and conjunctivitis. Furthermore, 119/201 children (59%) were regularly exposed to furred animals.There was an association between DDA and the sum of VAS for asthma during the pollen seasons.The BHR was significantly more pronounced in those with than those without DDA during all three seasons: Using the three cut offs, the difference was most pronounced during the winter season but reached also significance using the cut off limit 0.5 mg/ml during the birch pollen season.Doctor diagnosed asthma correlated to PC20 during the seasons for most of the cut off limits for PC20 and in general there was an association in PC20 between the seasons independent of cut off limits.Furthermore, DDA, but not BHR, correlated to exposure to traffic and there was an association between exposure to traffic and industrial pollution, but not to ETS or duration of breastfeeding.Conclusion: The most striking feature of school children with uncomplicated hay-fever was the high frequency of DDA and BHR, most pronounced during the winter, the high frequency of exposure to living animals and sensitization to indoor allergens. Hay-fever is a generalized disease. Even without obvious asthma, BHR is common and most children have symptoms from both the eyes and the airways. Diagnosis of asthma in children with hay-fever and early anti-inflammatory treatment may improve the prognosis.
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| 7. |
- Gren, Louise, et al.
(författare)
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Effect of renewable fuels and intake O2 concentration on diesel engine emission characteristics and reactive oxygen species (ROS) formation
- 2020
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Ingår i: Atmosphere. - : MDPI AG. - 2073-4433. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- Renewable diesel fuels have the potential to reduce net CO2 emissions, and simultaneously decrease particulate matter (PM) emissions. This study characterized engine-out PM emissions and PM-induced reactive oxygen species (ROS) formation potential. Emissions from a modern heavy-duty diesel engine without external aftertreatment devices, and fueled with petroleum diesel, hydrotreated vegetable oil (HVO) or rapeseed methyl ester (RME) biodiesel were studied. Exhaust gas recirculation (EGR) allowed us to probe the effect of air intake O2 concentration, and thereby combustion temperature, on emissions and ROS formation potential. An increasing level of EGR (decreasing O2 concentration) resulted in a general increase of equivalent black carbon (eBC) emissions and decrease of NOx emissions. At a medium level of EGR (13% intake O2), eBC emissions were reduced for HVO and RME by 30 and 54% respectively compared to petroleum diesel. In general, substantially lower emissions of polycyclic aromatic hydrocarbons (PAHs), including nitro and oxy-PAHs, were observed for RME compared to both HVO and diesel. At low-temperature combustion (LTC, O2 < 10%), CO and hydrocarbon gas emissions increased and an increased fraction of refractory organic carbon and PAHs were found in the particle phase. These altered soot properties have implications for the design of aftertreatment systems and diesel PM measurements with optical techniques. The ROS formation potential per mass of particles increased with increasing engine O2 concentration intake. We hypothesize that this is because soot surface properties evolve with the combustion temperature and become more active as the soot matures into refractory BC, and secondly as the soot surface becomes altered by surface oxidation. At 13% intake O2, the ROS-producing ability was high and of similar magnitude per mass for all fuels. When normalizing by energy output, the lowered emissions for the renewable fuels led to a reduced ROS formation potential.
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| 8. |
- Jacobsen, Annette, et al.
(författare)
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Reference gene selection for qPCR Is dependent on cell type rather than treatment in colonic and vaginal human epithelial cell lines
- 2014
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Ingår i: PLOS ONE. - San Fransisco, USA : Punlic Library of Science. - 1932-6203. ; 9:12, s. e115592-
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Tidskriftsartikel (refereegranskat)abstract
- The ability of commensal bacteria to influence gene expression in host cells under the influence of pathogenic bacteria has previously been demonstrated, however the extent of this interaction is important for understanding how bacteria can be used as probiotics. Real-time quantitative polymerase chain reaction is the most sensitive tool for evaluating relative changes to gene expression levels. However as a result of its sensitivity an appropriate method of normalisation should be used to account for any variation incurred in preparatory experimental procedures. These variations may result from differences in the amount of starting material, quality of extracted RNA, or in the efficiency of the reverse transcriptase or polymerase enzymes. Selection of an endogenous control gene is the preferred method of normalisation, and ideally a proper validation of the gene's appropriateness for the study in question should be performed. In this study we used quantitative polymerase chain reaction data and applied four different algorithms (geNorm, BestKeeper, NormFinder, and comparative ΔCq) to evaluate eleven different genes as to their suitability as endogenous controls for use in studies involving colonic (HT-29) and vaginal (VK2/E6E7) human mucosal epithelial cells treated with probiotic and pathogenic bacteria. We found phosphoglycerate kinase 1 to be most appropriate for HT-29 cells, and ribosomal protein large P0 to be the best choice for VK2/E6E7 cells. We also showed that use of less stable reference genes can lead to less accurate quantification of expression levels of gene of interest (GOI) and also can result in decreased statistical significance for GOI expression levels when compared to control. Additionally, we found the cell type being analysed had greater influence on reference gene selection than the treatment performed. This study provides recommendations for stable endogenous control genes for use in further studies involving colonic and vaginal cell lines after bacterial challenge.
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| 9. |
- Jacobsen, Annette V., et al.
(författare)
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Effects of perfluorooctane sulfonate on genes controlling hepatic fatty acid metabolism in livers of chicken embryos
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Berlin/Heidelberg. - 0944-1344 .- 1614-7499. ; 25:23, s. 23074-23081
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Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFAS) are synthetic surfactants with a wide variety of applications; however, due to their stability, they are particularly resistant to degradation and, as such, are classed as persistent organic pollutants. Perfluorooctane sulfonate (PFOS) is one such PFAS that is still detectable in a range of different environmental settings, despite its use now being regulated in numerous countries. Elevated levels of PFOS have been detected in various avian species, and the impact of this on avian health is of interest when determining acceptable levels of PFOS in the environment. Due to its similarities to naturally occurring fatty acids, PFOS has potential to disrupt a range of biological pathways, particularly those associated with lipid metabolism, and this has been shown in various species. In this study, we have investigated how in ovo exposure to environmentally relevant levels of PFOS affects expression of genes involved in lipid metabolism of developing chicken embryos. We have found a broad suppression of transcription of genes involved in fatty acid oxidation and PPAR-mediated transcription with more significant effects apparent at lower doses of PFOS. These results highlight the need for more research investigating the biological impacts of low levels of PFAS to properly inform environmental policy governing their regulation.
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| 10. |
- Jensen, Jette Nygaard, et al.
(författare)
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Comparison of antibiotic prescribing and antimicrobial resistance in urinary tract infections at the municipal level among women in two Nordic regions
- 2018
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 73:8, s. 2207-2214
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To describe and compare the prescribing of antibiotics used for urinary tract infections and its correlation with resistance in Escherichia coli in urinary samples across two adjacent regions - the Capital Region and the Skaane Region - and their municipalities in Denmark and Sweden. Methods: The Capital Region consists of 29 municipalities and 725 960 female inhabitants aged ≥18 years and the Skaane Region consists of 33 municipalities and 515 668 female inhabitants aged ≥18 years. Aggregated data from outpatient care on the prescribing of pivmecillinam, trimethoprim and nitrofurantoin from both regions were analysed. The Department of Clinical Microbiology in both regions provided data on E. coli resistance in urinary samples from women aged ≥18 years. Data were measured as the number of prescriptions/1000 women/year, number of DDDs/1000 women/year and DDDs/prescription. Correlation analyses between antibiotic prescribing and antibiotic resistance rates were performed. Results: Antibiotic prescribing and resistance rates were significantly higher in the Capital Region compared with the Skaane Region. Large variations in prescription and resistance rates were found at the municipal level, but there were no correlations between the antibiotic prescription and resistance rates when each region was analysed separately. Conclusions: Although closely related, there are large differences in antibiotic prescribing and antibiotic resistance. It is suggested that the regional guidelines are an important driver and explanatory factor for the variations; however, further research is needed in this new field and factors such as the influence of cultural aspects should be the target of further research.
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