| 1. |
- Gummesson, Anders, 1973, et al.
(författare)
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Relations of Adipose Tissue Cell Death-Inducing DFFA-like Effector A Gene Expression to Basal Metabolic Rate, Energy Restriction and Obesity: Population-based and Dietary Intervention Studies.
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:12, s. 4759-65
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Tidskriftsartikel (refereegranskat)abstract
- Context: Cell death-inducing DFFA-like effector A (CIDEA) could be a potential target for the treatment of obesity via the modulation of metabolic rate, based on the findings that CIDEA inhibits the brown adipose tissue uncoupling process in rodents. Objective: To investigate the putative link between CIDEA and basal metabolic rate in humans, and to further elucidate the role of CIDEA in human obesity. Design: We have explored CIDEA gene expression in adipose tissue in two different human studies: A cross-sectional and population-based study assessing body composition and metabolic rate (Mölndal Metabolic study, n=92), and a longitudinal intervention-study of obese subjects treated with a very low calorie diet (VLCD study, n=24). Results: The CIDEA gene was predominantly expressed in adipocytes as compared to other human tissues. CIDEA gene expression in adipose tissue was inversely associated with basal metabolic rate independently of body composition, age and gender (p=0.014). VLCD induced an increase in adipose tissue CIDEA expression (p<0.0001) with a subsequent decrease in response to refeeding (p<0.0001). Reduced CIDEA gene expression was associated with a high body fat content (p<0.0001) and with high insulin levels (p<0.01). No dysregulation of CIDEA expression was observed in individuals with the metabolic syndrome when compared with BMI-matched controls. In a separate sample of VLCD-treated subjects (n=10), uncoupling protein 1 expression was reduced during diet (p=0.0026) and inversely associated with CIDEA expression (p=0.0014). Conclusion: The findings are consistent with the concept that CIDEA plays a role in adipose tissue energy expenditure.
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| 2. |
- Olofsson, Louise, 1977, et al.
(författare)
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CCAAT/enhancer binding protein alpha (C/EBPalpha) in adipose tissue regulates genes in lipid and glucose metabolism and a genetic variation in C/EBPalpha is associated with serum levels of triglycerides.
- 2008
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 93:12, s. 4880-6
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: CCAAT/enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in adipogenesis and hepatic glucose and lipid metabolism. OBJECTIVE: The aim of the study was to test the hypothesis that adipose tissue C/EBPalpha regulates genes in lipid and glucose metabolism and to test for an association between a polymorphism in C/EBPalpha and metabolic parameters. DESIGN AND METHODS: Adipose tissue C/EBPalpha mRNA expression was analyzed at four time points in obese subjects with (n = 12) and without (n = 12) the metabolic syndrome during caloric restriction (450 kcal/d for 16 wk) using DNA microarray and real-time PCR. Adenoviral overexpression of C/EBPalpha was used to identify genes regulated by C/EBPalpha in 3T3-L1 cells. Association between a genetic variation in C/EBPalpha (rs12691) and metabolic parameters was tested in the Swedish Obese Subjects (SOS) study (n = 528) and replicated in Finnish individuals from the Botnia type 2 diabetes study (n = 4,866). RESULTS: During caloric restriction, adipose tissue C/EBPalpha mRNA levels were reduced in subjects with the metabolic syndrome (P = 0.024) and correlated to metabolic parameters. In 3T3-L1 cells, C/EBPalpha regulated the expression of adiponectin; hexokinase 2; lipoprotein lipase; diacylglycerol O-acyltransferase 1 and 2; ATP-binding cassette, sub-family D, member 2; acyl-coenzyme A synthetase long-chain family member 1; CD36; and hydroxysteroid 11-beta dehydrogenase 1. Furthermore, the expression of the human homologs, except adiponectin, correlated to C/EBPalpha mRNA levels in human adipose tissue. The AA genotype of rs12691 was associated with higher serum triglyceride levels in the SOS study (P = 0.022), and this association was replicated in the Botnia study (P = 0.041). CONCLUSIONS: Adipose tissue C/EBPalpha regulates several genes in glucose and lipid metabolism, and a genetic variation in C/EBPalpha is associated with triglycerides in two independent populations.
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| 3. |
- Agarkova, Irina, et al.
(författare)
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The molecular composition of the sarcomeric M-band correlates with muscle fiber type
- 2004
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Ingår i: European Journal of Cell Biology. - 0171-9335. ; 83:5, s. 193-204
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Tidskriftsartikel (refereegranskat)abstract
- The M-band is the transverse structure that cross-links the thick filaments in the center and provides a perfect alignment of the A-band in the activated sarcomere. The molecular composition of the M-bands in adult mouse skeletal muscle is fiber-type dependent. All M-bands in fast fibers contain M-protein while M-bands in slow fibers contain a significant proportion of the EH-myomesin isoform, previously detected only in embryonic heart muscle. This fiber-type specificity develops during the first postnatal weeks. However, the ratio between the amounts of myosin and of myomesin, taken as sum of both isoforms, remains nearly constant in all studied muscles. Ultrastructural analysis demonstrates that some of the soleus fibers show a diffuse appearance of the M-band, resembling the situation in the embryonic heart. A model is proposed to explain the functional consequence of differential M-band composition for the physiological and morphological properties of sarcomeres in different muscle types.
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| 4. |
- Andersson-Assarsson, Johanna C., 1974, et al.
(författare)
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Evolution of age-related mutation-driven clonal haematopoiesis over 20 years is associated with metabolic dysfunction in obesity
- 2023
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Ingår i: Ebiomedicine. - 2352-3964. ; 92
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Tidskriftsartikel (refereegranskat)abstract
- Background Haematopoietic clones caused by somatic mutations with >= 2% variant allele frequency (VAF) increase with age and are linked to risk of haematological malignancies and cardiovascular disease. Recent observations suggest that smaller clones (VAF<2%) are also associated with adverse outcomes. Our aims were to determine the prevalence of clonal haematopoiesis driven by clones of variable sizes in individuals with obesity treated by usual care or bariatric surgery (a treatment that improves metabolic status), and to examine the expansion of clones in relation to age and metabolic dysregulation over up to 20 years.Methods Clonal haematopoiesis-driver mutations (CHDMs) were identified in blood samples from participants of the Swedish Obese Subjects intervention study. Using an ultrasensitive assay, we analysed single-timepoint samples from 1050 individuals treated by usual care and 841 individuals who had undergone bariatric surgery, and multiple-timepoint samples taken over 20 years from a subset (n = 40) of the individuals treated by usual care.Findings In this explorative study, prevalence of CHDMs was similar in the single-timepoint usual care and bariatric surgery groups (20.6% and 22.5%, respectively, P = 0.330), with VAF ranging from 0.01% to 31.15%. Clone sizes increased with age in individuals with obesity, but not in those who underwent bariatric surgery. In the multiple-timepoint analysis, VAF increased by on average 7% (range -4% to 24%) per year and rate of clone growth was negatively associated with HDL-cholesterol (R = -0.68, 1.74 E-04).Interpretation Low HDL-C was associated with growth of haematopoietic clones in individuals with obesity treated by usual care.
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| 5. |
- Andersson, Björn, 1977, et al.
(författare)
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Decrease in adiponectin levels correlates to growth response in growth hormone-treated children.
- 2009
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Ingår i: Hormone research. - : S. Karger AG. - 1423-0046 .- 0301-0163. ; 71:4, s. 213-8
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Tidskriftsartikel (refereegranskat)abstract
- Adiponectin is secreted by adipose tissue and circulates in human plasma at high levels. Decreased adiponectin levels are associated with insulin resistance and obesity. The aim of this study was to investigate whether changes in serum adiponectin levels are related to the growth response, insulin levels and insulin resistance during growth hormone (GH) treatment.
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| 6. |
- Andersson, C, et al.
(författare)
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The three ZNT8 autoantibody variants together improve the diagnostic sensitivity of childhood and adolescent type 1 diabetes
- 2011
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Ingår i: Autoimmunity. - : Taylor & Francis. - 0891-6934 .- 1607-842X. ; 44:5, s. 394-405
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Tidskriftsartikel (refereegranskat)abstract
- Aims: We tested whether autoantibodies to all three ZnT8RWQ variants, GAD65, insulinoma-associated protein 2 (IA-2), insulin and autoantibodies to islet cell cytoplasm (ICA) in combination with human leukocyte antigen (HLA) would improve the diagnostic sensitivity of childhood type 1 diabetes by detecting the children who otherwise would have been autoantibody-negative.Methods: A total of 686 patients diagnosed in 1996–2005 in Skåne were analyzed for all the seven autoantibodies [arginin 325 zinc transporter 8 autoantibody (ZnT8RA), tryptophan 325 zinc transporter 8 autoantibody (ZnT8WA), glutamine 325 Zinc transporter 8 autoantibody (ZnT8QA), autoantibodies to glutamic acid decarboxylase (GADA), Autoantibodies to islet-antigen-2 (IA-2A), insulin autoantibodies (IAA) and ICA] in addition to HLA-DQ genotypes.Results: Zinc transporter 8 autoantibody to either one or all three amino acid variants at position 325 (ZnT8RWQA) was found in 65% (449/686) of the patients. The frequency was independent of age at diagnosis. The ZnT8RWQA reduced the frequency of autoantibody-negative patients from 7.5 to 5.4%—a reduction by 28%. Only 2 of 108 (2%) patients who are below 5 years of age had no autoantibody at diagnosis. Diagnosis without any islet autoantibody increased with increasing age at onset. DQA1-B1*X-0604 was associated with both ZnT8RA (p = 0.002) and ZnT8WA (p = 0.01) but not with ZnT8QA (p = 0.07). Kappa agreement analysis showed moderate (>0.40) to fair (>0.20) agreement between pairs of autoantibodies for all combinations of GADA, IA-2A, ZnT8RWQA and ICA but only slight ( < 0.19) agreement for any combination with IAA.Conclusions: This study revealed that (1) the ZnT8RWQA was common, independent of age; (2) multiple autoantibodies were common among the young; (3) DQA1-B1*X-0604 increased the risk for ZnT8RA and ZnT8WA; (4) agreement between autoantibody pairs was common for all combinations except IAA. These results suggest that ZnT8RWQA is a necessary complement to the classification and prediction of childhood type 1 diabetes as well as to randomize the subjects in the prevention and intervention of clinical trials.
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| 7. |
- Andersson, Maria, 1975, et al.
(författare)
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Differential global gene expression response patterns of human endothelium exposed to shear stress and intraluminal pressure
- 2005
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Ingår i: J Vasc Res. - : S. Karger AG. - 1018-1172. ; 42:5, s. 441-52
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the global gene expression response of endothelium exposed to shear stress and intraluminal pressure and tested the hypothesis that the two biomechanical forces induce a differential gene expression response pattern. Intact living human conduit vessels (umbilical veins) were exposed to normal or high intraluminal pressure, or to low or high shear stress in combination with a physiological level of the other force in a unique vascular ex vivo perfusion system. Gene expression profiling was performed by the Affymetrix microarray technology on endothelial cells isolated from stimulated vessels. Biomechanical forces were found to regulate a very large number of genes in the vascular endothelium. In this study, 1,825 genes were responsive to mechanical forces, which corresponds to 17% of the expressed genes. Among pressure-responsive genes, 647 genes were upregulated and 519 genes were down regulated, and of shear stress-responsive genes, 133 genes were upregulated and 771 down regulated. The fraction of genes that responded to both pressure and shear stimulation was surprisingly low, only 13% of the regulated genes. Our results indicate that the two different stimuli induce distinct gene expression response patterns, which can also be observed when studying functional groups. Considering the low number of overlapping genes, we suggest that the endothelial cells can distinguish between shear stress and pressure stimulation.
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| 8. |
- Behre, Carl Johan, 1968, et al.
(författare)
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Dissociation between adipose tissue expression and serum levels of adiponectin during and after diet-induced weight loss in obese subjects with and without the metabolic syndrome
- 2007
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Ingår i: Metabolism: Clinical and Experimental. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 56:8, s. 1022-8
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Tidskriftsartikel (refereegranskat)abstract
- The study aimed to examine if dysmetabolic subjects (MetS+) have lower adiponectin gene expression and lower circulating adiponectin levels than non-dysmetabolic obese subjects (MetS-) at baseline, if adiponectin expression and adiponectin concentration rise more in the dysmetabolic group during weight loss, and if v-SNARE Vti1a (vesicle transport soluble NSF attachment protein receptor vps10p tail interacting 1a) expression increases during the weight loss, as a mechanism for increased adiponectin secretion. Twenty-one obese MetS+ and 19 obese MetS- subjects underwent a very low-energy diet for 16 weeks followed by 2 weeks of refeeding. Abdominal subcutaneous adipose tissue biopsies and blood samples were taken before, during, and after dieting for DNA microarray, reverse transcriptase-polymerase chain reaction, and biochemical analyses. Serum adiponectin was also assessed in a sex- and age-matched healthy, nonobese reference group. Weight decreased by 26.3+/-9.8 kg in the MetS+ group and 28.2+/-8.4 kg in the MetS- group with concomitant reductions in insulin, hemoglobin A1c, and triglycerides that were more pronounced in the MetS+ group. Initially, the MetS+ subjects had lower serum adiponectin, but the differences disappeared at week 8, with a continuous increase in serum adiponectin throughout the study in both groups to a level that was higher than in the reference group. The expression of adiponectin and v-SNARE Vti1a did not differ between the groups or over time. In conclusion, obese subjects with the metabolic syndrome had lower circulating adiponectin than subjects without the syndrome. Weight loss increased serum levels of adiponectin without a parallel increase in adiponectin gene expression. The mechanisms involved in the regulation of adiponectin levels merits further investigation.
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| 9. |
- Benson, Mikael, 1954, et al.
(författare)
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DNA microarray analysis of chromosomal susceptibility regions to identify candidate genes for allergic disease: A pilot study
- 2004
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 124:7, s. 813-819
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Tidskriftsartikel (refereegranskat)abstract
- Objective-To examine whether DNA microarray analysis of chromosomal susceptibility regions for allergy can help to identify candidate genes. Material and Methods-Nasal biopsies were obtained from 23 patients with allergic rhinitis and 12 healthy controls. RNA was extracted from the biopsies and pooled into three patient and three control pools. These were then analysed in duplicate with DNA microarrays containing 12626 genes. Candidate genes were further examined in nasal biopsies (real-time polymerase chain reaction) and blood samples (single nucleotide polymorphisms) from other patients with allergic rhinitis and from controls. Results-A total of 37 differentially expressed genes were identified according to criteria involving both the size and consistency of the gene expression levels. The chromosomal location of these genes was compared with the chromosomal susceptibility regions for allergic disease. Using a statistical method, five genes were identified in these regions, including serine protease inhibitor, Kazal type, 5 (SPINK5) and HLA-DRB2. The relevance of these genes was examined in other patients with allergic rhinitis and in controls; none of the genes were differentially expressed in nasal biopsies. Moreover, no association between allergic rhinitis and SPINK5 polymorphisms was found, at either the genotype or haplotype level. Conclusions-DNA microarray analysis of chromosomal susceptibility regions did not lead to identification of candidate genes that could be validated in a new material. However, because gene polymorphisms may cause differential gene expression, further studies, including validation data, are needed to examine this approach.
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