| 1. |
- Elias, Erik, 1979, et al.
(författare)
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Central nervous system lipocalin-type prostaglandin D2-synthase is correlated with orexigenic neuropeptides, visceral adiposity and markers of the hypothalamic-pituitary-adrenal axis in obese humans.
- 2011
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Ingår i: Journal of neuroendocrinology. - : Wiley. - 1365-2826 .- 0953-8194. ; 23:6, s. 501-7
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Tidskriftsartikel (refereegranskat)abstract
- Lipocalin-type prostaglandin D2-synthase (L-PGDS) is the main producer of prostaglandin D2 (PGD2) in the central nervous system (CNS). Animal data suggest effects of central nervous L-PGDS in the regulation of food intake and obesity. No human data are available. We hypothesised that a role for CNS L-PGDS in metabolic function in humans would be reflected by correlations with known orexigenic neuropeptides. Cerebrospinal fluid (CSF) and serum samples were retrieved from 26 subjects in a weight loss study, comprising a 3-week dietary lead-in followed by 12-weeks of leptin or placebo treatment. At baseline, CSF L-PGDS was positively correlated with neuropeptide Y (NPY) (ρ=0.695, P<0.001, n=26) and galanin (ρ=0.651, P<0.001) as well as visceral adipose tissue (ρ=0.415, P=0.035). Furthermore, CSF L-PGDS was inversely correlated with CSF leptin (ρ=-0.529, P=0.005) and tended to correlate inversely with s.c. adipose tissue (ρ=-0.346, P=0.084). As reported earlier, leptin treatment had no effect on weight loss and did not affect CSF L-PGDS or NPY levels compared to placebo. After weight loss, the change of CSF L-PGDS was significantly correlated with the change of CSF NPY levels (ρ=0.604, P=0.004, n=21). Because of the correlation between baseline CSF L-PGDS levels and visceral adipose tissue, we examined associations with hypothalamic-pituitary-adrenal (HPA) axis components. Baseline CSF L-PGDS was correlated with corticotrophin-releasing hormone (ρ=0.764, P<0.001) and β-endorphin (ρ=0.491, P<0.001). By contrast, serum L-PGDS was not correlated with any of the measured variables either at baseline or after treatment. In summary, CSF L-PGDS was correlated with orexigenic neuropeptides, visceral fat distribution and central HPA axis mediators. The importance of these findings is unclear but could suggest a role for CSF L-PGDS in the regulation of visceral obesity by interaction with the neuroendocrine circuits regulating appetite and fat distribution. Further interventional studies will be needed to characterise these interactions in more detail.
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| 2. |
- Elias, Erik, 1979, et al.
(författare)
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Bone mineral density and expression of vitamin D receptor-dependent calcium uptake mechanisms in the proximal small intestine after bariatric surgery
- 2014
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Ingår i: British Journal of Surgery. - : Oxford University Press (OUP). - 0007-1323 .- 1365-2168. ; 101:12, s. 1566-1575
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Tidskriftsartikel (refereegranskat)abstract
- Background Roux-en-Y gastric bypass may lead to impaired calcium uptake. Therefore, operation-specific effects of gastric bypass and vertical banded gastroplasty on bone mineral density (BMD) were examined in a randomized clinical trial. Bone resorption markers and mechanisms of decreased calcium uptake after gastric bypass were investigated using blood and endoscopic samples from two additional patient cohorts. Methods Total BMD and non-weight-bearing skull BMD were measured by dual-energy X-ray absorptiometry at baseline, and 1 and 6years after gastric bypass or vertical banded gastroplasty in patients who were not receiving calcium supplements. Bone resorption markers in serum and calcium uptake mechanisms in jejunal mucosa biopsies were analysed after gastric bypass by proteomics including radioimmunoassay, gel electrophoresis and mass spectrometry. Results One year after surgery, weight loss was similar after gastric bypass and vertical banded gastroplasty. There was a moderate decrease in skull BMD after gastric bypass, but not after vertical banded gastroplasty (P<0·001). Between 1 and 6years after gastric bypass, skull BMD and total BMD continued to decrease (P=0·001). C-terminal telopeptide levels in serum had increased twofold by 18months after gastric bypass. Proteomic analysis of the jejunal mucosa revealed decreased levels of heat-shock protein 90β, a co-activator of the vitamin D receptor, after gastric bypass. Despite increased vitamin D receptor levels, expression of the vitamin D receptor-regulated calcium transporter protein TRPV6 decreased. Conclusion BMD decreases independently of weight after gastric bypass. Bone loss might be attributed to impaired calcium absorption caused by decreased activation of vitamin D-dependent calcium absorption mechanisms mediated by heat-shock protein 90β and TRPV6.
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| 3. |
- Elias, Erik, 1979, et al.
(författare)
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Erythrocyte sodium-lithium countertransport activity is inversely correlated to adiponectin, retinol binding protein 4 and body height.
- 2010
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Ingår i: Scandinavian journal of clinical and laboratory investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 70:7, s. 487-91
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Tidskriftsartikel (refereegranskat)abstract
- We have previously described that the sodium/lithium countertransport (SLC) in the erythrocyte cell membrane is closely linked to obesity and insulin resistance. Adiponectin and retinol-binding protein 4 (RBP-4) are believed to affect obesity and insulin resistance. In the present study, we aimed to further characterize the relationship between SLC, inflammatory markers, adiponectin and RBP-4.
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| 4. |
- Wallenius, Ville, 1970, et al.
(författare)
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The lipocalins retinol-binding protein-4, lipocalin-2 and lipocalin-type prostaglandin D2-synthase correlate with markers of inflammatory activity, alcohol intake and blood lipids, but not with insulin sensitivity in metabolically healthy 58-year-old Swedish men
- 2011
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Ingår i: Experimental and clinical endocrinology & diabetes. - : Georg Thieme Verlag KG. - 1439-3646 .- 0947-7349. ; 119:2, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- The lipocalins retinol-binding protein (RBP)-4, lipocalin-2 and lipocalin-type prostaglandin D-synthase (L-PGDS) have been suggested to mediate obesity-associated insulin resistance and other metabolic co-morbidities. The role of lipocalins is however controversial and it is unclear whether they have a physiological role in regulation of insulin sensitivity and metabolic function in clinically healthy humans. Therefore, we examined the correlations between serum levels of RBP-4, L-PGDS and lipocalin-2 and insulin sensitivity and other metabolic parameters in non-diabetic subjects selected to display variations in insulin sensitivity. 100 clinically healthy 58-year-old Swedish men were selected by stratified sampling among 818 screened subjects to represent quintiles of varying degrees of insulin sensitivity. Insulin sensitivity was measured by the euglycaemic hyperinsulinaemic clamp method. Serum levels of lipocalins and cytokines were determined using antibody-based techniques. Serum lipids were measured by standardized laboratory methods. None of the measured lipocalins showed any correlations with insulin sensitivity. However, we found that lipocalin-2 and L-PGDS were correlated with each other, but not with RBP-4. Lipocalin-2 and L-PGDS were positively correlated with soluble TNF- receptors 1 and 2 and negatively with alcohol consumption and serum HDL. Further, lipocalin-2 was correlated with interleukin-6 whereas RBP-4 was negatively correlated with TNF-α. □These results suggest that RBP-4, lipocalin-2 and L-PGDS do not regulate insulin sensitivity in healthy men. Rather the expression levels of lipocalin-2 and L-PGDS, but not RBP-4, seemed to reflect inflammatory activity and were inversely correlated with alcohol intake and serum HDL levels.
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