| 1. |
- Idoia Biurrun, Idoia, et al.
(författare)
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GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands
- 2019
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Ingår i: Palaearctic Grasslands. - : Eurasian Dry Grassland Group (EDGG). - 2627-9827. ; :44, s. 26-47
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Tidskriftsartikel (refereegranskat)abstract
- GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phytocoenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems.
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| 2. |
- Biurrun, Idoia, et al.
(författare)
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Benchmarking plant diversity of Palaearctic grasslands and other open habitats
- 2021
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Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
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Tidskriftsartikel (refereegranskat)abstract
- Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
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| 3. |
- de Jong, Jasper M. A., et al.
(författare)
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Human brown adipose tissue is phenocopied by classical brown adipose tissue in physiologically humanized mice
- 2019
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Ingår i: Nature Metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 1:8, s. 830-843
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Tidskriftsartikel (refereegranskat)abstract
- Human and rodent brown adipose tissues (BAT) appear morphologically and molecularly different. Here we compare human BAT with both classical brown and brite/beige adipose tissues of 'physiologically humanized' mice: middle-aged mice living under conditions approaching human thermal and nutritional conditions, that is, prolonged exposure to thermoneutral temperature (approximately 30 degrees C) and to an energy-rich (high-fat, high-sugar) diet. We find that the morphological, cellular and molecular characteristics (both marker and adipose-selective gene expression) of classical brown fat, but not of brite/beige fat, of these physiologically humanized mice are notably similar to human BAT. We also demonstrate, both in silico and experimentally, that in physiologically humanized mice only classical BAT possesses a high thermogenic potential. These observations suggest that classical rodent BAT is the tissue of choice for translational studies aimed at recruiting human BAT to counteract the development of obesity and its comorbidities.
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| 4. |
- de Jong, Jasper, 1987-
(författare)
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Who is Who in the Adipose Organ : A look at the Heterogeneity of Adipocyte Biology
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increasing prevalence of obesity and related health complications, such as type 2 diabetes, cardiovascular disease and cancer, demands thorough investigation of the underlying processes. One of the key tissues investigated in this context is adipose tissue. It is becoming increasingly clear that adipose tissue is a very dynamic and heterogenic organ. This thesis provides an overview of various aspects of adipose biology that illustrate its heterogenic nature and describes my own scientific contributions to this field.We typically distinguish between thermogenic, energy-expending brown adipocytes and energy-storing white adipocytes that are located in anatomically distinct adipose depots. In addition, brite (or beige) adipocytes are functionally thermogenic, but are located among white adipocytes. Related to functional variation, adipocytes and adipose tissues display a wide range of morphological appearances. An additional property that illustrates the heterogeneity among adipose cells and depots is the variation of cellular responses to physiological cues, such as changes in diet or environmental temperature. Furthermore, the developmental origins of various adipose types display great heterogeneity, which may explain some of the functional and dynamic differences that are observed.In line with the complexity of developmental origins, molecular markers that were initially proposed to distinguish between brown, brite/beige and white adipose subtypes have added to the notion that the composition of the adipose organ is much more complex than has long been appreciated.My own work has contributed to the enhancement of our understanding of the heterogeneity of adipose subtypes. In particular, my findings related to marker gene expression patterns have led to increased appreciation of the complex nature of adipose gene expression patterns and the complications of translating results obtained in mice to humans. Some of my other contributions have increased the understanding of the differences and similarities in thermogenic adipose tissue functionality and dynamics. With cell culture studies, I have revealed new characteristics of pre-adipose cells from various depots that further add to the appreciation of the adipose heterogeneity.Overall, this thesis provides an overview of important characteristics of the adipose organ, illustrating its heterogenic nature. Realization of this heterogeneity is of importance in order to properly study the adipose organ to ultimately understand how the adipose organ can be therapeutically targeted to effectively treat adipose-related diseases.
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| 5. |
- Massier, Lucas, et al.
(författare)
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An integrated single cell and spatial transcriptomic map of human white adipose tissue
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Single-cell studies of human white adipose tissue (WAT) provide insights into the specialized cell types in the tissue. Here the authors combine publicly available and newly generated high-resolution and bulk transcriptomic results from multiple human datasets to provide a comprehensive cellular map of white adipose tissue. To date, single-cell studies of human white adipose tissue (WAT) have been based on small cohort sizes and no cellular consensus nomenclature exists. Herein, we performed a comprehensive meta-analysis of publicly available and newly generated single-cell, single-nucleus, and spatial transcriptomic results from human subcutaneous, omental, and perivascular WAT. Our high-resolution map is built on data from ten studies and allowed us to robustly identify >60 subpopulations of adipocytes, fibroblast and adipogenic progenitors, vascular, and immune cells. Using these results, we deconvolved spatial and bulk transcriptomic data from nine additional cohorts to provide spatial and clinical dimensions to the map. This identified cell-cell interactions as well as relationships between specific cell subtypes and insulin resistance, dyslipidemia, adipocyte volume, and lipolysis upon long-term weight changes. Altogether, our meta-map provides a rich resource defining the cellular and microarchitectural landscape of human WAT and describes the associations between specific cell types and metabolic states.
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| 6. |
- Meen, Astri J., et al.
(författare)
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Obesity Is Associated with Distorted Proteoglycan Expression in Adipose Tissue
- 2023
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 24:8
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Tidskriftsartikel (refereegranskat)abstract
- Proteoglycans are central components of the extracellular matrix (ECM) and binding partners for inflammatory chemokines. Morphological differences in the ECM and increased inflammation are prominent features of the white adipose tissues in patients with obesity. The impact of obesity and weight loss on the expression of specific proteoglycans in adipose tissue is not well known. This study aimed to investigate the relationship between adiposity and proteoglycan expression. We analyzed transcriptomic data from two human bariatric surgery cohorts. In addition, RT-qPCR was performed on adipose tissues from female and male mice fed a high-fat diet. Both visceral and subcutaneous adipose tissue depots were analyzed. Adipose mRNA expression of specific proteoglycans, proteoglycan biosynthetic enzymes, proteoglycan partner molecules, and other ECM-related proteins were altered in both human cohorts. We consistently observed more profound alterations in gene expression of ECM targets in the visceral adipose tissues after surgery (among others VCAN (p = 0.000309), OGN (p = 0.000976), GPC4 (p = 0.00525), COL1A1 (p = 0.00221)). Further, gene analyses in mice revealed sex differences in these two tissue compartments in obese mice. We suggest that adipose tissue repair is still in progress long after surgery, which may reflect challenges in remodeling increased adipose tissues. This study can provide the basis for more mechanistic studies on the role of proteoglycans in adipose tissues in obesity.
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| 7. |
- Rohm, Maria, et al.
(författare)
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An AMP-activated protein kinase-stabilizing peptide ameliorates adipose tissue wasting in cancer cachexia in mice
- 2016
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 22:10, s. 1120-1130
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Tidskriftsartikel (refereegranskat)abstract
- Cachexia represents a fatal energy-wasting syndrome in a large number of patients with cancer that mostly results in a pathological loss of skeletal muscle and adipose tissue. Here we show that tumor cell exposure and tumor growth in mice triggered a futile energy-wasting cycle in cultured white adipocytes and white adipose tissue (WAT), respectively. Although uncoupling protein 1 (Ucp1)-dependent thermogenesis was dispensable for tumor-induced body wasting, WAT from cachectic mice and tumor-cell-supernatant-treated adipocytes were consistently characterized by the simultaneous induction of both lipolytic and lipogenic pathways. Paradoxically, this was accompanied by an inactivated AMP-activated protein kinase (Ampk), which is normally activated in peripheral tissues during states of low cellular energy. Ampk inactivation correlated with its degradation and with upregulation of the Ampk-interacting protein Cidea. Therefore, we developed an Ampk-stabilizing peptide, ACIP, which was able to ameliorate WAT wasting in vitro and in vivo by shielding the Cidea-targeted interaction surface on Ampk. Thus, our data establish the Ucp1-independent remodeling of adipocyte lipid homeostasis as a key event in tumor-induced WAT wasting, and we propose the ACIP-dependent preservation of Ampk integrity in the WAT as a concept in future therapies for cachexia.
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| 8. |
- Zhang, Qian, et al.
(författare)
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The glucose-dependent insulinotropic polypeptide (GIP) regulates body weight and food intake via CNS-GIPR signaling
- 2021
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Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 33:4, s. 833-844
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Tidskriftsartikel (refereegranskat)abstract
- Uncertainty exists as to whether the glucose-dependent insulinotropic polypeptide receptor (GIPR) should be activated or inhibited for the treatment of obesity. Gipr was recently demonstrated in hypothalamic feeding centers, but the physiological relevance of CNS Gipr remains unknown. Here we show that HFD-fed CNS-Gipr KO mice and humanized (h)GIPR knockin mice with CNS-hGIPR deletion show decreased body weight and improved glucose metabolism. In DIO mice, acute central and peripheral administration of acyl-GIP increases cFos neuronal activity in hypothalamic feeding centers, and this coincides with decreased body weight and food intake and improved glucose handling. Chronic central and peripheral administration of acyl-GIP lowers body weight and food intake in wild-type mice, but shows blunted/absent efficacy in CNS-Gipr KO mice. Also, the superior metabolic effect of GLP-1/GIP co-agonism relative to GLP-1 is extinguished in CNS-Gipr KO mice. Our data hence establish a key role of CNS Gipr for control of energy metabolism.
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