| 1. |
- Andersson, Niklas, 1970, et al.
(författare)
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A variant near the interleukin-6 gene is associated with fat mass in Caucasian men
- 2010
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 34:6, s. 1011-9
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Regulation of fat mass appears to be associated with immune functions. Studies of knockout mice show that endogenous interleukin (IL)-6 can suppress mature-onset obesity. OBJECTIVE: To systematically investigate associations of single nucleotide polymorphisms (SNPs) near the IL-6 (IL6) and IL-6 receptor (IL6R) genes with body fat mass, in support for our hypothesis that variants of these genes can be associated with obesity. DESIGN AND STUDY SUBJECTS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a population-based cross-sectional study of 18- to 20-year-old men (n=1049), from the Gothenburg area (Sweden). Major findings were confirmed in two additional cohorts consisting of elderly men from the Osteoporotic Fractures in Men (MrOS) Sweden (n=2851) and MrOS US (n=5611) multicenter population-based studies. MAIN OUTCOME: The genotype distributions and their association with fat mass in different compartments, measured with dual-energy X-ray absorptiometry. RESULTS: Out of 18 evaluated tag SNPs near the IL6 and IL6R genes, a recently identified SNP rs10242595 G/A (minor allele frequency=29%) 3' of the IL6 gene was negatively associated with the primary outcome total body fat mass (effect size -0.11 standard deviation (s.d.) units per A allele, P=0.02). This negative association with fat mass was also confirmed in the combined MrOS Sweden and MrOS US cohorts (effect size -0.05 s.d. units per A allele, P=0.002). When all three cohorts were combined (n=8927, Caucasian subjects), rs10242595(*)A showed a negative association with total body fat mass (effect size -0.05 s.d. units per A allele, P<0.0002). Furthermore, the rs10242595(*)A was associated with low body mass index (effect size -0.03, P<0.001) and smaller regional fat masses. None of the other SNPs investigated in the GOOD study were reproducibly associated with body fat. CONCLUSIONS: The IL6 gene polymorphism rs10242595(*)A is associated with decreased fat mass in three combined cohorts of 8927 Caucasian men.
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| 2. |
- Graff, M., et al.
(författare)
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Genome-wide physical activity interactions in adiposity. A meta-analysis of 200,452 adults
- 2017
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Ingår i: PLoS Genet. - : Public Library of Science (PLoS). - 1553-7404 .- 1553-7390. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Physical activity (PA) may modify the genetic effects that give rise to increased risk of obesity. To identify adiposity loci whose effects are modified by PA, we performed genome-wide interaction meta-analyses of BMI and BMI-adjusted waist circumference and waist-hip ratio from up to 200,452 adults of European (n = 180,423) or other ancestry (n = 20,029). We standardized PA by categorizing it into a dichotomous variable where, on average, 23% of participants were categorized as inactive and 77% as physically active. While we replicate the interaction with PA for the strongest known obesity-risk locus in the FTO gene, of which the effect is attenuated by similar to 30% in physically active individuals compared to inactive individuals, we do not identify additional loci that are sensitive to PA. In additional genome-wide meta-analyses adjusting for PA and interaction with PA, we identify 11 novel adiposity loci, suggesting that accounting for PA or other environmental factors that contribute to variation in adiposity may facilitate gene discovery.
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| 3. |
- Sarwar, Nadeem, et al.
(författare)
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Interleukin-6 receptor pathways in coronary heart disease : a collaborative meta-analysis of 82 studies
- 2012
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Ingår i: The Lancet. - New York, NY, USA : Elsevier. - 0140-6736 .- 1474-547X. ; 379:9822, s. 1205-1213
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Tidskriftsartikel (refereegranskat)abstract
- Background: Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied a functional genetic variant known to affect IL6R signalling. Methods: In a collaborative meta-analysis, we studied Asp358Ala (rs2228145) in IL6R in relation to a panel of conventional risk factors and inflammation biomarkers in 125 222 participants. We also compared the frequency of Asp358Ala in 51 441 patients with coronary heart disease and in 136 226 controls. To gain insight into possible mechanisms, we assessed Asp358Ala in relation to localised gene expression and to postlipopolysaccharide stimulation of interleukin 6. Findings: The minor allele frequency of Asp358Ala was 39%. Asp358Ala was not associated with lipid concentrations, blood pressure, adiposity, dysglycaemia, or smoking (p value for association per minor allele >= 0.04 for each). By contrast, for every copy of 358Ala inherited, mean concentration of IL6R increased by 34.3% (95% CI 30.4-38.2) and of interleukin 6 by 14.6% (10.7-18.4), and mean concentration of C-reactive protein was reduced by 7.5% (5.9-9.1) and of fibrinogen by 1.0% (0.7-1.3). For every copy of 358Ala inherited, risk of coronary heart disease was reduced by 3.4% (1.8-5.0). Asp358Ala was not related to IL6R mRNA levels or interleukin-6 production in monocytes. Interpretation: Large-scale human genetic and biomarker data are consistent with a causal association between IL6R-related pathways and coronary heart disease.
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| 4. |
- Shao, Linus Ruijin, 1964, et al.
(författare)
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Down-Regulation of Cilia-Localized IL-6R{alpha} by 17{beta}-Estradiol in Mouse and Human Fallopian Tubes.
- 2009
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Ingår i: American journal of physiology. Cell physiology. - : American Physiological Society. - 0363-6143 .- 1522-1563. ; 297:1
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Tidskriftsartikel (refereegranskat)abstract
- The action of Interleukin-6 (IL-6) impacts female reproduction. Although IL-6 was recently shown to inhibit cilia activity in human fallopian tubes in vitro, the molecular mechanisms underlying IL-6 signaling to tubal function remain elusive. Here, we investigate the cellular localization, regulation, and possible function of two IL-6 receptors (IL-6Ralpha and gp130) in mouse and human fallopian tubes in vivo. We show that IL-6Ralpha is restricted to the cilia of epithelial cells in both mouse and human fallopian tubes. Exogenous 17beta-estradiol (E2), but not progesterone (P4), causes a time-dependent decrease in IL-6Ralpha expression which is blocked by the estrogen receptor (ER) antagonist ICI 182,780. Exposure of different ER-selective agonists, PTT or DPN, demonstrated an ER subtype-specific regulation of IL-6Ralphaalpha in mouse fallopian tubes. In contrast to IL-6Ralpha, gp130 was detected in tubal epithelial cells in mice but not in humans. In humans, gp130 was found in the muscle cells and was decreased in the periovulatory and luteal phases during the reproductive cycles, indicating a species-specific expression and regulation of gp130 in the fallopian tube. Expression of tubal IL-6Ralpha and gp130 in IL-6 knockout mice was found to be normal; however, E2 treatment increased IL-6Ralpha, but not gp130, in IL-6 knockout mice compared to wild-type mice. Furthermore, expression levels of IL-6Ralpha, but not gp130, decreased in parallel with estrogenic accelerated oocyte-cumulus complex (OCC) transport in mouse fallopian tubes. Our findings unveil a potential role for cilia-specific IL-6Ralpha in the regulation of OCC transport and suggest an estrogen-regulatory pathway of IL-6Ralpha in the fallopian tube. Key words: estrogen, IL-6R, cilia, fallopian tube.
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| 5. |
- Tivesten, Åsa, 1969, et al.
(författare)
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Liver-derived insulin-like growth factor-I is involved in the regulation of blood pressure in mice.
- 2002
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Ingår i: Endocrinology. - 0013-7227. ; 143:11, s. 4235-42
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Tidskriftsartikel (refereegranskat)abstract
- IGF-I has been suggested to be of importance for cardiovascular structure and function, but the relative role of locally produced and liver-derived endocrine IGF-I remains unclear. Using the Cre-LoxP recombination system, we have previously created transgenic mice with a liver-specific, inducible IGF-I knockout (LI-IGF-I-/-). To examine the role of liver-derived IGF-I in cardiovascular physiology, liver-derived IGF-I was inactivated at 4 wk of age, resulting in a 79% reduction of serum IGF-I levels. At 4 months of age, systolic blood pressure (BP) was increased in LI-IGF-I-/- mice. Echocardiography showed increased posterior wall thickness in combination with decreased stroke volume and cardiac output, whereas other systolic variables were unchanged, suggesting that these cardiac effects were secondary to increased peripheral resistance. Acute nitric oxide-synthase inhibition increased systolic BP more in LI-IGF-I-/- mice than in control mice. LI-IGF-I-/- mice showed impaired acetylcholine-induced vasorelaxation in mesenteric resistance vessels and increased levels of endothelin-1 mRNA in aorta. Thus, the increased peripheral resistance in LI-IGF-I-/- mice might be attributable to endothelial dysfunction associated with increased expression of endothelin-1 and impaired vasorelaxation of resistance vessels. In conclusion, our findings suggest that liver-derived IGF-I is involved in the regulation of BP in mice.
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| 6. |
- Andersson, Niklas, 1970, et al.
(författare)
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Variants of the interleukin-1 receptor antagonist gene are associated with fat mass in men
- 2009
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 33:5, s. 525-533
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Tidskriftsartikel (refereegranskat)abstract
- Context: Immune functions seem to have connections to variations in body fat mass. Studies of knockout mice indicate that endogenous interleukin (IL)-1 can suppress mature-onset obesity. Objective: To systematically investigate our hypotheses that single- nucleotide polymorphisms (SNPs) and/or haplotypes variants in the IL-1 gene system are associated with fat mass. Subjects: The Gothenburg osteoporosis and obesity determinants (GOOD) study is a population-based cross-sectional study of 18-20 year-old men (n = 1068), from Gothenburg, Sweden. Major findings were confirmed in elderly men (n = 3014) from the Swedish part of the osteoporotic fractures in men (MrOS) multicenter population-based study. Main Outcome Measure: The genotype distributions and their association with body fat mass in different compartments, measured with dual-energy X-ray absorptiometry (DXA). Results: Out of 15 investigated SNPs in the IL-1 receptor antagonist (IL1RN) gene, a recently identified 30 untranslated region C4T (rs4252041, minor allele frequency 4%) SNP was associated with the primary outcome total fat mass (P = 0.003) and regional fat masses, but not with lean body mass or serum IL-1 receptor 1 (IL1RN) levels. This SNP was also associated with body fat when correcting the earlier reported IL1RN_2018 T4C (rs419598) SNP (in linkage disequilibrium with a well-studied variable number tandem repeat of 86 bp). The association between rs4252041 SNP and body fat was confirmed in the older MrOS population (P = 0.03). The rs4252041 SNP was part of three haplotypes consisting of five adjacent SNPs that were identified by a sliding window approach. These haplotypes had a highly significant global association with total body fat (P < 0.001). None of the other investigated members of the IL-1 gene family displayed any SNPs that have not been described previously to be significantly associated with body fat. Conclusions: The IL1RN gene, shown to enhance obesity by suppressing IL-1 effects in experimental animals, have no previously described gene polymorphisms and haplotypes that are associated with fat, but not lean mass in two populations of men. International Journal of Obesity (2009) 33, 525-533; doi: 10.1038/ijo.2009.47; published online 17 March 2009
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| 7. |
- Bake, Tina, et al.
(författare)
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The gravitostat protects diet-induced obese rats against fat accumulation and weight gain
- 2021
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Ingår i: Journal of Neuroendocrinology. - : Wiley. - 0953-8194 .- 1365-2826. ; 33:8
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Tidskriftsartikel (refereegranskat)abstract
- The gravitostat is a novel homeostatic body weight-regulating mechanism, mostly studied in mice, and recently confirmed in obese humans. In the present study, we explored the effect of weight loading on metabolic outcomes, meal patterns and parameters linked to energy expenditure in both obese and lean rats. Diet-induced obese (DIO) and lean rats were implanted with capsules weighing either 15% of biological body weight (load) or empty capsules (1.3% of body weight; controls). Loading protected against fat accumulation more markedly in the DIO group. In line with this, the obesity-related impairment in insulin sensitivity was notably ameliorated in DIO rats upon loading, as revealed by the reduction in serum insulin levels and homeostatic model assessment for insulin resistance index scores. Although 24-hour caloric intake was reduced in both groups, this effect was greater in loaded DIO rats than in loaded lean peers. During days 10-16, after recovery from surgery, loading: (i) decreased meal size in both groups (only during the light phase in DIO rats) but this was compensated in lean rats by an increase in meal frequency; (ii) reduced dark phase locomotor activity only in lean rats; and (iii) reduced mean caloric efficiency in DIO rats. Muscle weight was unaffected by loading in either group. Dietary-obese rats are therefore more responsive than lean rats to loading.
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| 8. |
- Benrick, Anna, 1979, et al.
(författare)
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A non-conservative polymorphism in the IL-6 signal transducer (IL6ST)/gp130 is associated with myocardial infarction in a hypertensive population.
- 2008
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Ingår i: Regulatory peptides. - : Elsevier BV. - 0167-0115. ; 146:1-3, s. 189-96
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation is a key component in the development of atherosclerosis, and myocardial infarction (MI); therefore we investigated the association between an interleukin-6 signal transducer (IL6ST)/gp130 polymorphism, gp130 function and risk of MI. Structural modeling suggested that a non-conservative single nucleotide polymorphism in the gp130, Gly148Arg, can change the stability and functional properties of the molecule. In vitro studies were done with BAF/3 cells lacking endogenous gp130. Cells stably transfected with the gp130 148Arg variant proliferated less and showed slightly lower STAT-3 phosphorylation in response to gp130 stimulation as compared to cells transfected with gp130 148Gly. In a prospectively followed hypertensive cohort we identified 167 patients who suffered a MI during the study and compared them to matched controls (mean age 57 years, 73% males, n=482). Carriers of the 148Arg variant (f(Arg)=0.12) of the gp130 receptor had decreased odds ratio for MI in univariate analysis (0.56, 95% CI 0.34-0.91, p=0.02). In conclusion, a genetically determined structural variant of the IL-6 receptor subunit gp130 is, independently of other known risk factors, associated with decreased risk of MI. The variant is also associated with decreased IL-6 responsiveness and could lead to a configuration change in the gp130 receptor.
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| 9. |
- Berndt, Sonja I., et al.
(författare)
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Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 501-U69
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Tidskriftsartikel (refereegranskat)abstract
- Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.
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| 10. |
- Botusan, I. R., et al.
(författare)
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Deficiency of liver-derived insulin-like growth factor-I (IGF-I) does not interfere with the skin wound healing rate
- 2018
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Objective: IGF-I is a growth factor, which is expressed in virtually all tissues. The circulating IGF-I is however derived mainly from the liver. IGF-I promotes wound healing and its levels are decreased in wounds with low regenerative potential such as diabetic wounds. However, the contribution of circulating IGF-I to wound healing is unknown. Here we investigated the role of systemic IGF-I on wound healing rate in mice with deficiency of liver-derived IGF-I (LI-IGF-I-/- mice) during normal (normoglycemic) and impaired wound healing (diabetes). Methods: LI-IGF-I-/- mice with complete inactivation of the IGF-I gene in the hepatocytes were generated using the Cre/loxP recombination system. This resulted in a 75% reduction of circulating IGF-I. Diabetes was induced with streptozocin in both LI-IGF-I-/- and control mice. Wounds were made on the dorsum of the mice, and the wound healing rate and histology were evaluated. Serum IGF-I and GH were measured by RIA and ELISA respectively. The expression of IGF-I, IGF-II and the IGF-I receptor in the skin were evaluated by qRT-PCR. The local IGF-I protein expression in different cell types of the wounds during wound healing process was analyzed using immunohistochemistry. Results: The wound healing rate was similar in LI-IGF-I-/- mice to that in controls. Diabetes significantly delayed the wound healing rate in both LI-IGF-I-/- and control mice. However, no significant difference was observed between diabetic animals with normal or reduced hepatic IGF-I production. The gene expression of IGF-I, IGF-II and IGF-I receptor in skin was not different between any group of animals tested. Local IGF-I levels in the wounds were similar between of LI-IGF-I-/- and WT mice although a transient reduction of IGF-I expression in leukocytes in the wounds of LI-IGF-I-/- was observed seven days post wounding. Conclusion: Deficiency in the liver-derived IGF-I does not affect wound healing in mice, neither in normo-glycemic conditions nor in diabetes.
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