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| 2. |
- Hansson, Björn, et al.
(författare)
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Rosiglitazone drives cavin-2/SDPR expression in adipocytes in a CEBPα-dependent manner
- 2017
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Caveolae are abundant adipocyte surface domains involved in insulin signaling, membrane trafficking and lipid homeostasis. Transcriptional control mechanisms for caveolins and cavins, the building blocks of caveolae, are thus arguably important for adipocyte biology and studies in this area may give insight into insulin resistance and diabetes. Here we addressed the hypothesis that one of the less characterized caveolar components, cavin-2 (SDPR), is controlled by CCAAT/Enhancer Binding Protein (CEBPα) and Peroxisome Proliferator- Activated Receptor Gamma (PPARG). Using human mRNA expression data we found that SDPR correlated with PPARG in several tissues. This was also observed during differentiation of 3T3-L1 fibroblasts into adipocytes. Treatment of 3T3-L1-derived adipocytes with the PPARγ-activator Rosiglitazone increased SDPR and CEBPα expression at both the mRNA and protein levels. Silencing of CEBPα antagonized these effects. Further, adenoviral expression of PPARγ/CEBPα or Rosiglitazone-treatment increased SDPR expression in primary rat adipocytes. The myocardin family coactivator MKL1 was recently shown to regulate SDPR expression in human coronary artery smooth muscle cells. However, we found that actin depolymerization, known to inhibit MKL1 and MKL2, was without effect on SDPR mRNA levels in adipocytes, even though overexpression of MKL1 and MKL2 had the capacity to increase caveolins and cavins and to repress PPARγ/CEBPα. Altogether, this work demonstrates that CEBPα expression and PPARγ-activity promote SDPR transcription and further supports the emerging notion that PPARγ/CEBPα and MKL1/MKL2 are antagonistic in adipocytes.
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| 3. |
- Heyman Lindén, Lovisa, et al.
(författare)
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Lingonberries alter the gut microbiota and prevent low-grade inflammation in high-fat diet fed mice
- 2016
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Ingår i: Food & Nutrition Research. - : SNF Swedish Nutrition Foundation. - 1654-6628 .- 1654-661X. ; 60
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Tidskriftsartikel (refereegranskat)abstract
- Background: The gut microbiota plays an important role in the development of obesity and obesity-associated impairments such as low-grade inflammation. Lingonberries have been shown to prevent diet-induced obesity and low-grade inflammation. However, it is not known whether the effect of lingonberry supplementation is related to modifications of the gut microbiota. The aim of the present study was to describe whether consumption of different batches of lingonberries alters the composition of the gut microbiota, which could be relevant for the protective effect against high fat (HF)-induced metabolic alterations. Methods: Three groups of C57BL/6J mice were fed HF diet with or without a supplement of 20% lingonberries from two different batches (Lingon1 and Lingon2) during 11 weeks. The composition and functionality of the cecal microbiota were assessed by 16S rRNA sequencing and PICRUSt. In addition, parameters related to obesity, insulin sensitivity, hepatic steatosis, inflammation and gut barrier function were examined. Results: HF-induced obesity was only prevented by the Lingon1 diet, whereas both batches of lingonberries reduced plasma levels of markers of inflammation and endotoxemia (SAA and LBP) as well as modified the composition and functionality of the gut microbiota, compared to the HF control group. The relative abundance of Akkermansia and Faecalibacterium, genera associated with healthy gut mucosa and antiinflammation, was found to increase in response to lingonberry intake. Conclusions: Our results show that supplementation with lingonberries to an HF diet prevents low-grade inflammation and is associated with significant changes of the microbiota composition. Notably, the antiinflammatory properties of lingonberries seem to be independent of effects on body weight gain.
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| 4. |
- Kotowska, Dorota, et al.
(författare)
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Evaluating Google Street View for tracking invasive alien plants along roads
- 2021
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Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X .- 1872-7034. ; 121
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Tidskriftsartikel (refereegranskat)abstract
- Invasive alien plants are considered a major driver of global biodiversity loss. Therefore, there is a huge demand of spatial and temporal data on their distribution for investigating possible drivers of species invasions and for predictions of future distributions. We use Google Street View imagery (GSV) as a new source of spatial and temporal data. GSV provides millions of panoramic views along road networks worldwide allowing for the identification of many plant species, including invasive ones. Thus, GSV has a great potential to support ecological research in documenting species distribution, but reliable validation of its precision and accuracy is lacking. Here, we describe and evaluate an approach using GSV to visually track the spread of invasive alien plants, the North American goldenrods (Solidago canadensis and S. gigantea) occurring abundantly along road network in Poland (Central Europe). We determined presence/absence of the species along 160 randomly selected transects of a length of 500 m by visual inspection of GSV images and compared it with field surveys at the same transects. We show that the occurrence of goldenrods in GSV is a reliable predictor of their occurrence in the wild. Sampling parameters, like road width, season when GSV pictures were taken and number of months elapsed since taking the GSV pictures, did not change the correlation between outputs of the two methods (GSV and field sampling). Furthermore, both the occurrence of goldenrods observed in the field and their occurrence in GSV have similar relations to habitat characteristics investigated (the same direction of relationship and similar effect size). We suggest Google Street View images may be an additional tool to be used in the detection and tracking of the spread of invasive alien plants along roadsides. The approach may be useful in assessing temporal changes in roadside vegetation and managing problematic plant species across large spatial scales and may contribute to the further development of more efficient sampling methods in ecological studies.
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| 5. |
- Kotowska, Dorota, et al.
(författare)
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Ranging behaviour and habitat use in Montagu's Harrier Circus pygargus in extensive farmland of Eastern Poland
- 2021
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 162, s. 325-337
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Tidskriftsartikel (refereegranskat)abstract
- Agriculture intensification drives changes in bird populations but also in the space use by farmland species. Agriculture in Eastern Europe still follows an extensive farming model, but due to policy shifts aimed at rural restructuring and implementation of government subsidies for farmers, it is being rapidly intensified. Here, we aimed to document the ranging behaviour and habitat use of a declining farmland bird of prey-Montagu's Harrier-and to compare it to findings from Western Europe. In 2011-2018, 50 individuals were followed with GPS loggers in Eastern Poland to study species spatial ecology. We found home ranges (kernel 90%) to be considerably large: 67.3 (+/- 42.3) km(2) in case of males, but only 4.9 (+/- 6.1) km(2) in females. Home ranges overlapped by 40%, on average, with other males in colonies and by 61%, on average, between consecutive breeding seasons of a particular male. The average daily distance travelled by males and females reached, respectively, 94.5 and 45.3 km, covering a daily home range of 32.3 and 3.1 km(2). Individuals foraged up to 35 km from nests (3.5 km on average). Daily distance travelled and daily home ranges varied across the breeding season, in case of females being shortest in July, but sharply increasing in August. Also, individuals with breeding success had higher daily distance travelled but smaller daily home ranges. Average harriers' distance to nest was generally increasing over the season, but was also changing over time of day: birds were closest to nest during night time, but at the end of the season, males roosted up to 16 km from the nest. While foraging males slightly preferred grasslands, higher elevation and smaller land-use patches, they avoided slopes and proximity of roads. We conclude that the surprisingly large home ranges of breeding harriers may suggest reduced prey availability or high fragmentation of hunting areas, both driving birds to utilise large areas and potentially contributing to population decline.
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| 6. |
- Kotowska, Dorota, et al.
(författare)
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Short-term lingonberry feeding is associated with decreased insulin levels and altered adipose tissue function in high-fat diet fed C57BL/6J mice
- 2022
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Ingår i: Journal of Functional Foods. - : Elsevier BV. - 1756-4646. ; 94, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Intact adipose tissue function is essential to maintain glucose and lipid homeostasis. To study the impact of altered adipose tissue function on whole-body metabolism, diet-induced obesity in mice is frequently used as a model organism. In the current study, we have examined health-promoting effects of a lingonberry supplemented diet. We found C57BL/6J mice fed a high-fat diet supplemented with lingonberry for 4 days to have significantly lowered body-weight gain, adipose tissue expansion, and reduced insulin levels, compared to mice fed an isocaloric high-fat diet. RNA-Seq analysis of epididymal adipose tissue revealed differential expression of genes related to mitochondria fission (Mief1, Dnm1, Vps35, and Opa1). Further, we detected increased gene expression and phosphorylation of perilipin-1 (pS522), and increased lipolysis in primary adipocytes from lingonberry-fed mice. Together, these data pinpoint that beneficial effects of a lingonberry enriched diet are rapidly detectable and that the adipose tissue constitutes a target for these effects.
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| 7. |
- Kotowska, Dorota, et al.
(författare)
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The use of socio-economy in species distribution modelling: Features of rural societies improve predictions of barn owl occurrence
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 741
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Tidskriftsartikel (refereegranskat)abstract
- Variation of habitats and resources important for farmland birds seems to be only partly captured by ordinary statistics on land-use and agricultural production. For instance, densities of rodents being prey for owls and raptors or structures of rural architecture providing nesting sites for many species are central for bird diversity but are not reported in any official statistics. Thus, modelling species distributions, population abundance and trends of farmland birds may miss important predictive habitat elements. Here, we involve local socio-economy factors as a source of additional information on rural habitat to test whether it improves predictions of barn owl occurrence in 2768 churches across Poland. Barn owls occurred in 778 churches and seemed to prefer old churches made of brick located in regions with a milder climate, higher share of arable land and pastures, low road density and low levels of light pollution. Including data on local unemployment, the proportion of elder citizens, commune income per citizen, the share of citizens with high education and share of farmers among working population improved the model substantially and some of these variables predicted barn owl occurrence better than several land-use and climate data. Barn owls were more likely to occur in areas with high unemployment, a higher proportion of older citizens in a local population and higher share of farmers among working population. Importantly, the socio-economy variables were correlated with the barn owl occurrence despite all climatic, infrastructure and land-use data were present in the model. We conclude that the socio-economy of local socie-ties may add important but overlooked information that links to spatial variation in farmland biodiversity. (C) 2020 Elsevier B.V. All rights reserved.
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| 8. |
- Krawczyk, Katarzyna, et al.
(författare)
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Myocardin Family Members Drive Formation of Caveolae.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- Caveolae are membrane organelles that play roles in glucose and lipid metabolism and in vascular function. Formation of caveolae requires caveolins and cavins. The make-up of caveolae and their density is considered to reflect cell-specific transcriptional control mechanisms for caveolins and cavins, but knowledge regarding regulation of caveolae genes is incomplete. Myocardin (MYOCD) and its relative MRTF-A (MKL1) are transcriptional coactivators that control genes which promote smooth muscle differentiation. MRTF-A communicates changes in actin polymerization to nuclear gene transcription. Here we tested if myocardin family proteins control biogenesis of caveolae via activation of caveolin and cavin transcription. Using human coronary artery smooth muscle cells we found that jasplakinolide and latrunculin B (LatB), substances that promote and inhibit actin polymerization, increased and decreased protein levels of caveolins and cavins, respectively. The effect of LatB was associated with reduced mRNA levels for these genes and this was replicated by the MRTF inhibitor CCG-1423 which was non-additive with LatB. Overexpression of myocardin and MRTF-A caused 5-10-fold induction of caveolins whereas cavin-1 and cavin-2 were induced 2-3-fold. PACSIN2 also increased, establishing positive regulation of caveolae genes from three families. Full regulation of CAV1 was retained in its proximal promoter. Knock down of the serum response factor (SRF), which mediates many of the effects of myocardin, decreased cavin-1 but increased caveolin-1 and -2 mRNAs. Viral transduction of myocardin increased the density of caveolae 5-fold in vitro. A decrease of CAV1 was observed concomitant with a decrease of the smooth muscle marker calponin in aortic aneurysms from mice (C57Bl/6) infused with angiotensin II. Human expression data disclosed correlations of MYOCD with CAV1 in a majority of human tissues and in the heart, correlation with MKL2 (MRTF-B) was observed. The myocardin family of transcriptional coactivators therefore drives formation of caveolae and this effect is largely independent of SRF.
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| 9. |
- Lindahl, Maria, et al.
(författare)
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ApoA-I Milano stimulates lipolysis in adipose cells independently of cAMP/PKA activation.
- 2015
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Ingår i: Journal of Lipid Research. - 1539-7262. ; 56:12, s. 2248-2259
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Tidskriftsartikel (refereegranskat)abstract
- ApoA-I, the main protein component of high-density lipoprotein (HDL), is suggested to be involved in metabolic homeostasis. We examined the effects of Milano, a naturally occurring ApoA-I variant, about which little mechanistic information is available. Remarkably, high fat-fed mice treated with Milano displayed a rapid weight loss greater than ApoA-I WT treated mice, and a significantly reduced adipose tissue mass, without an inflammatory response. Further, lipolysis in adipose cells isolated from mice treated with either WT or Milano was increased. In primary rat adipose cells, Milano stimulated cholesterol efflux and increased glycerol release, independently of β-adrenergic stimulation and phosphorylation of hormone sensitive lipase (Ser563) and perilipin (Ser522). Stimulation with Milano had a significantly greater effect on glycerol release compared with WT but similar effect on cholesterol efflux. Pharmacological inhibition or siRNA silencing of ABCA-1 did not diminish Milano-stimulated lipolysis, although binding to the cell surface was decreased, as analyzed by fluorescence microscopy. Interestingly, methyl-β-cyclodextrin, a well-described cholesterol acceptor, dose-dependently stimulated lipolysis. Together, these results suggest that decreased fat mass and increased lipolysis following Milano treatment in vivo is partly explained by a novel mechanism at the adipose cell level comprising stimulation of lipolysis independently of the canonical cAMP/PKA signaling pathway.
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| 10. |
- Martyka, Rafal, et al.
(författare)
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Age- and trait-dependent breeding responses to environmental variation in a short-lived songbird
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Breeding responses of organisms to environmental changes may profoundly depend on an individual's age, as an age-environment interaction may be expected to affect the expression of reproductive traits. However, little is known about how this interaction affects short-lived species that experience various environmental conditions in adulthood. Here, we used a 32-year dataset from the collared flycatcher, Ficedula albicollis, population to test whether and how the environment interacts with age to shape female age-specific reproduction. To characterise environmental variation, we applied the remotely sensed normalised difference vegetation index (NDVI), estimating vegetation productivity, and used it as a surrogate for habitat quality. Then, we analysed how within-individual age and NDVI determine patterns in laying date, clutch size, offspring production, and recruitment. We found that young and old females, but not middle-aged females, breeding under low NDVI started to lay eggs later and produced smaller clutches than females of the same age breeding under higher NDVI. No such effects were observed for offspring production or recruitment. Our study provides evidence that both an individual's age and the environmental variation experienced during adulthood may be crucial for shaping reproductive patterns in short-lived avian species, as has been found in long-lived birds.
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