| 1. |
- Olsson, Maja, 1975, et al.
(författare)
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Establishment of a transgenic mouse model specifically expressing human serum amyloid a in adipose tissue.
- 2011
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- Obesity and obesity co-morbidities are associated with a low grade inflammation and elevated serum levels of acute phase proteins, including serum amyloid A (SAA). In the non-acute phase in humans, adipocytes are major producers of SAA but the function of adipocyte-derived SAA is unknown. To clarify the role of adipocyte-derived SAA, a transgenic mouse model expressing human SAA1 (hSAA) in adipocytes was established. hSAA expression was analysed using real-time PCR analysis. Male animals were challenged with a high fat (HF) diet. Plasma samples were subjected to fast protein liquid chromatography (FPLC) separation. hSAA, cholesterol and triglyceride content were measured in plasma and in FPLC fractions. Real-time PCR analysis confirmed an adipose tissue-specific hSAA gene expression. Moreover, the hSAA gene expression was not influenced by HF diet. However, hSAA plasma levels in HF fed animals (37.7±4.0 µg/mL, n=7) were increased compared to those in normal chow fed animals (4.8±0.5 µg/mL, n=10; p<0.001), and plasma levels in the two groups were in the same ranges as in obese and lean human subjects, respectively. In FPLC separated plasma samples, the concentration of hSAA peaked in high-density lipoprotein (HDL) containing fractions. In addition, cholesterol distribution over the different lipoprotein subfractions as assessed by FPLC analysis was similar within the two experimental groups. The established transgenic mouse model demonstrates that adipose tissue produced hSAA enters the circulation, resulting in elevated plasma levels of hSAA. This new model will enable further studies of metabolic effects of adipose tissue-derived SAA.
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| 2. |
- Saiki, Atsuhito, et al.
(författare)
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Tenomodulin is highly expressed in adipose tissue, increased in obesity, and down-regulated during diet-induced weight loss.
- 2009
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 94:10, s. 3987-94
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Tenomodulin (TNMD), a putative angiogenesis inhibitor, is expressed in hypovascular connective tissues. Global gene expression scans show that the TNMD gene also is expressed in human adipose tissue and that its expression is regulated in response to weight reduction; however, more detailed information is lacking. OBJECTIVE: The aim of this study was to investigate TNMD tissue distribution and TNMD gene expression in human adipose tissue in relation to obesity and metabolic disease. DESIGN, PATIENTS, AND INTERVENTIONS: TNMD gene expression, tissue distribution, and TNMD gene expression in adipose tissue from different depots, from lean and obese subjects, and during diet-induced weight reduction were analyzed by DNA microarray and real-time PCR. MAIN OUTCOME MEASURE: We primarily measured TNMD gene expression. RESULTS: The TNMD gene was predominantly expressed in sc adipose tissue. TNMD gene expression was higher in sc than omental adipose tissue both in lean (P = 0.002) and obese subjects (P = 0.014). In both women and men, TNMD gene expression was significantly higher in the obese subjects compared to the lean subjects (P = 1.1 x 10(-26) and P = 0.010, respectively). In a multiple linear regression analysis, BMI was a significant independent predictor of TNMD gene expression. TNMD gene expression was down-regulated during diet-induced weight loss, with a 65% decrease after 18 wk of diet (P < 0.0001). CONCLUSIONS: We conclude that human adipose tissue TNMD gene expression is highly affected by obesity, adipose tissue location, and weight loss, indicating that TNMD may play a role in adipose tissue function.
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| 3. |
- Ahlin, Sofie, 1985, et al.
(författare)
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Macrophage Gene Expression in Adipose Tissue is Associated with Insulin Sensitivity and Serum Lipid Levels Independent of Obesity.
- 2013
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Ingår i: Obesity (Silver Spring, Md.). - : Wiley. - 1930-739X .- 1930-7381. ; 21:12
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Obesity is linked to both increased metabolic disturbances and increased adipose tissue macrophage infiltration. However, whether macrophage infiltration directly influences human metabolism is unclear. The aim of this study was to investigate if there are obesity-independent links between adipose tissue macrophages and metabolic disturbances. Design and Methods: Expression of macrophage markers in adipose tissue was analyzed by DNA microarrays in the SOS Sib Pair study and in patients with type 2 diabetes and a BMI-matched healthy control group. Results: The expression of macrophage markers in adipose tissue was increased in obesity and associated with several metabolic and anthropometric measurements. After adjustment for BMI, the expression remained associated with insulin sensitivity, serum levels of insulin, C-peptide, high density lipoprotein cholesterol (HDL-cholesterol) and triglycerides. In addition, the expression of most macrophage markers was significantly increased in patients with type 2 diabetes compared to the control group. Conclusion: Our study shows that infiltration of macrophages in human adipose tissue, estimated by the expression of macrophage markers, is increased in subjects with obesity and diabetes and associated with insulin sensitivity and serum lipid levels independent of BMI. This indicates that adipose tissue macrophages may contribute to the development of insulin resistance and dyslipidemia.
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| 4. |
- Franck, Niclas, et al.
(författare)
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Identification of adipocyte genes regulated by caloric intake
- 2011
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : Endocrine society. - 0021-972X .- 1945-7197. ; 96:2, s. E413-E418
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Changes in energy intake have marked and rapid effects on metabolic functions and some of the effects may be due to changes in adipose tissue gene expression that precede alterations in body weight. OBJECTIVE: To identify genes in adipose tissue regulated by changes in caloric intake independent of changes in body weight. RESEARCH DESIGN AND METHODS: Obese subjects were given a very-low calorie diet (VLCD; 450 kcal/day) for 16 weeks. After the diet, ordinary food was gradually reintroduced during 2 weeks while there were minimal changes in body weight. Adipose tissue gene expression was measured by microarray analysis. First, genes regulated during caloric restriction and in the opposite direction during the weight stable re-feeding phase were identified. To verify opposite regulation to that observed during caloric restriction, identified genes were further analyzed using adipocyte expression profiles from healthy subjects before and after overfeeding. Results were confirmed using real time PCR or immunoassay. RESULTS: Using a significance level of p<0.05 for all comparisons, 52 genes were downregulated and 50 were up-regulated by caloric restriction and regulated in the opposite direction by re-feeding and overfeeding. Among these were genes that affect lipogenesis (ACLY, ACACA, FASN, SCD), protein synthesis (4EBP1, 4EBP2), beta-oxidation (CPT1B), liberation of fatty acids (CIDEA) and glyceroneogenesis (PCK2). Interestingly, several of these are under control of the master regulator mTOR. CONCLUSIONS: The observed transcriptional changes indicate that mTOR plays a central role in the control of diet-regulated adipocyte genes involved in lipogenesis and protein synthesis.
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| 5. |
- Hägg, Daniel, 1974, et al.
(författare)
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Expression profiling of macrophages from subjects with atherosclerosis to identify novel susceptibility genes.
- 2008
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Ingår i: International journal of molecular medicine. - 1107-3756 .- 1791-244X. ; 21:6, s. 697-704
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Tidskriftsartikel (refereegranskat)abstract
- Although a number of environmental risk factors for atherosclerosis have been identified, heredity seems to be a significant independent risk factor. The aim of our study was to identify novel susceptibility genes for atherosclerosis. The screening process consisted of three steps. First, expression profiles of macrophages from subjects with atherosclerosis were compared to macrophages from control subjects. Secondly, the subjects were genotyped for promoter region polymorphisms in genes with altered gene expression. Thirdly, a population of subjects with coronary heart disease and control subjects were genotyped to test for an association with identified polymorphisms that affected gene expression. Twenty-seven genes were differentially expressed in both macrophages and foam cells from subjects with atherosclerosis. Three of these genes, IRS2, CD86 and SLC11A1 were selected for further analysis. Foam cells from subjects homozygous for the C allele at the -765C-->T SNP located in the promoter region of IRS2 had increased gene expression compared to foam cells from subjects with the nonCC genotype. Also, macrophages and foam cells from subjects homozygous for allele 2 at a repeat element in the promoter region of SLC11A1 had increased gene expression compared to macrophages and foam cells from subjects with the non22 genotype. Genotyping of 512 pairs of subjects with coronary heart disease (CHD) and matched controls revealed that subjects homozygous for C of the IRS2 SNP had an increased risk for CHD; odds ratio 1.43, p=0.010. Immunohistochemical staining of human carotid plaques showed that IRS2 expression was localised to macrophages and endothelial cells in vivo. Our method provides a reliable approach for identifying susceptibility genes for atherosclerosis, and we conclude that elevated IRS2 gene expression in macrophages may be associated with an increased risk of CHD.
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| 6. |
- 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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| 7. |
- Olsson, Maja, 1975, et al.
(författare)
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Expression of the selenoprotein S (SELS) gene in subcutaneous adipose tissue and SELS genotype are associated with metabolic risk factors.
- 2011
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Ingår i: Metabolism: clinical and experimental. - : Elsevier BV. - 1532-8600. ; 60:1, s. 114-20
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Tidskriftsartikel (refereegranskat)abstract
- The selenoprotein S (SELS) is a putative receptor for serum amyloid A, and recent studies have suggested that SELS may be a link between type 2 diabetes mellitus and inflammation. Genetic studies of SELS polymorphisms have revealed associations with circulating levels of inflammatory markers and hard end points of cardiovascular disease. In this study, we analyzed SELS expression in subcutaneous adipose tissue and SELS genotype in relation to metabolic risk factors. DNA microarray expression analysis was used to study the expression of SELS in lean and obese siblings from the Swedish Obese Subjects Sib Pair Study. TaqMan genotyping was used to analyze 3 polymorphisms, previously found to be associated with circulating levels of inflammatory markers, in the INTERGENE case-control study of myocardial infarction and unstable angina pectoris. Possible associations between SELS genotype and/or expression with anthropometry and measures of metabolic status were investigated. Real-time polymerase chain reaction was used to analyze the SELS expression in isolated human adipocytes incubated with insulin. In lean subjects, we found correlations between SELS gene expression in subcutaneous adipose tissue and measures of obesity (waist, P = .045; sagittal diameter, P = .031) and blood pressure (diastolic, P = .016; systolic P = .015); and in obese subjects, we found correlations with measures of obesity (body mass index, P = .03; sagittal diameter, P = .008) and glycemic control (homeostasis model assessment of insulin resistance, P = .011; insulin, P = .009) after adjusting for age and sex. The 5227GG genotype was associated with serum levels of insulin (P = .006) and homeostasis model assessment of insulin resistance (P = .007). The expression of SELS increased after insulin stimulation in isolated human adipocytes (P = .008). In this study, we found an association between both SELS gene expression in adipose tissue and SELS genotype with measures of glycemic control. In vitro studies demonstrated that the SELS gene is regulated by insulin in human subcutaneous adipocytes. This study further supports a role for SELS in the development of metabolic disease, especially in the context of insulin resistance.
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| 8. |
- Bjarnason, Ragnar, 1959, et al.
(författare)
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Cartilage oligomeric matrix protein increases in serum after the start of growth hormone treatment in prepubertal children
- 2004
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 89:10, s. 5156-60
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Tidskriftsartikel (refereegranskat)abstract
- Both GH and IGF-I stimulate bone growth, but the molecular mechanisms mediating their effects on the growth plate are not fully understood. We measured gene expression by microarray analysis in primary cultured human chondrocytes treated with either GH or IGF-I. One of the genes found to be up-regulated by both GH and IGF-I was that encoding cartilage oligomeric matrix protein (COMP). This protein is predominantly found in the extracellular matrix of cartilage. Mutations in the COMP gene have been associated with syndromes of short stature. To verify that COMP is regulated by GH in vivo, we measured COMP levels in serum in short children treated with GH. The study included 113 short prepubertal children (14 girls and 99 boys) with a mean (+/- sd) age of 8.84 +/- 2.76 yr, height sd score of -2.74 +/- 0.67, and IGF-I sd score of -1.21 +/- 1.07 at the start of GH administration. Serum levels of COMP were 1.58 +/- 0.28, 1.83 +/- 0.28 (P < 0.0001), 1.91 +/- 0.28 (P < 0.0001), 1.78 +/- 0.28 (P < 0.001), and 1.70 +/- 0.24 (P < 0.05) microg/ml at baseline and after 1 wk and 1, 3, and 12 months, respectively.In conclusion, we have demonstrated that COMP expression is up-regulated by both GH and IGF-I in primary cultured human chondrocytes. Furthermore, serum levels of COMP increase after the start of GH treatment in short children.
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| 9. |
- Clark, Stephen J, et al.
(författare)
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Association of Sirtuin 1 (SIRT1) Gene SNPs and Transcript Expression Levels With Severe Obesity.
- 2012
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Ingår i: Obesity. - : Wiley. - 1930-7381. ; 20:1, s. 178-85
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have reported associations of sirtuin 1 (SIRT1) single nucleotide polymorphisms (SNPs) to both obesity and BMI. This study was designed to investigate association between SIRT1 SNPs, SIRT1 gene expression and obesity. Case-control analyses were performed using 1,533 obese subjects (896 adults, BMI >40kg/m(2) and 637 children, BMI >97th percentile for age and sex) and 1,237 nonobese controls, all French Caucasians. Two SNPs (in high linkage disequilibrium (LD), r(2) = 0.96) were significantly associated with adult obesity, rs33957861 (P value = 0.003, odds ratio (OR) = 0.75, confidence interval (CI) = 0.61-0.92) and rs11599176 (P value: 0.006, OR = 0.74, CI = 0.61-0.90). Expression of SIRT1 mRNA was measured in BMI-discordant siblings from 154 Swedish families. Transcript expression was significantly correlated to BMI in the lean siblings (r(2) = 0.13, P value = 3.36 × 10(-7)) and lower SIRT1 expression was associated with obesity (P value = 1.56 × 10(-35)). There was also an association between four SNPs (rs11599176, rs12413112, rs33957861, and rs35689145) and BMI (P values: 4 × 10(-4), 6 × 10(-4), 4 × 10(-4), and 2 × 10(-3)) with the rare allele associated with a lower BMI. However, no SNP was associated with SIRT1 transcript expression level. In summary, both SNPs and SIRT1 gene expression are associated with severe obesity.
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| 10. |
- Grund, Sofia, et al.
(författare)
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The autocrine motility factor receptor is overexpressed on the surface of B cells in Binet C chronic lymphocytic leukemia.
- 2011
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Ingår i: Medical Oncology. - : Springer Science and Business Media LLC. - 1559-131X .- 1357-0560. ; 28:4, s. 1542-8
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lymphocytic leukemia (CLL) is a heterogeneous disease with a clinical spectrum reaching from discrete lymphocytosis to extensive enlargement of lymph nodes, spleen and liver, and bone marrow failure. The aim of this study was to identify genes that differentiate between patients with disease stage A vs. C according to Binet in order to better understand the disease. To achieve this, we performed DNA microarray analysis on B cells from CLL patients with stage A and C according to Binet and matched controls. Between CLL patients and controls, there were 1,528 differentially expressed genes and 360 genes were differentially expressed between Binet A and C patients. Due to the sheer number of regulated genes, we focused on the autocrine motility factor receptor (AMFR). AMFR has not previously been investigated in hematological disorders, but high expression of AMFR correlates with a more advanced stage and invasive potential in several human tumors. AMFR mRNA expression was higher in Binet A compared with Binet C patients (P=0.0053) and healthy controls (P=0.0051). Total AMFR protein was higher in Binet A patients compared to Binet C as analyzed by intracellular flow cytometry. However, AMFR exist both in the ER involved in protein degradation and on the cell surface involved in metastasis and cell motility. Cell surface AMFR was increased in Binet C compared with Binet A+B (P=0.016). In conclusion, the mRNA levels reflect the total amount of AMFR, whereas cell surface expression is associated with progression in CLL.
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