| 1. |
- Braadland, Peder Rustoen, et al.
(författare)
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Low beta(2)-adrenergic receptor level may promote development of castration resistant prostate cancer and altered steroid metabolism
- 2016
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:2, s. 1878-1894
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Tidskriftsartikel (refereegranskat)abstract
- The underlying mechanisms responsible for the development of castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy are not fully understood. This is the first study to address whether beta(2)-adrenergic receptor (ADRB2)- mediated signaling may affect CRPC progression in vivo. By immunohistochemical analyses, we observed that low levels of ADRB2 is associated with a more rapid development of CRPC in a Norwegian patient cohort. To elucidate mechanisms by which ADRB2 may affect CRPC development, we stably transfected LNCaP cells with shRNAs to mimic low and high expression of ADRB2. Two UDP-glucuronosyltransferases, UGT2B15 and UGT2B17, involved in phase II metabolism of androgens, were strongly downregulated in two LNCaP shADRB2 cell lines. The low-ADRB2 LNCaP cell lines displayed lowered glucuronidation activities towards androgens than high-ADRB2 cells. Furthermore, increased levels of testosterone and enhanced androgen responsiveness were observed in LNCaP cells expressing low level of ADRB2. Interestingly, these cells grew faster than high-ADRB2 LNCaP cells, and sustained their low glucuronidation activity in castrated NOD/SCID mice. ADRB2 immunohistochemical staining intensity correlated with UGT2B15 staining intensity in independent TMA studies and with UGT2B17 in one TMA study. Similar to ADRB2, we show that low levels of UGT2B15 are associated with a more rapid CRPC progression. We propose a novel mechanism by which ADRB2 may affect the development of CRPC through downregulation of UGT2B15 and UGT2B17.
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| 2. |
- Falorni, Alberto, et al.
(författare)
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Determination of 21-hydroxylase autoantibodies: inter-laboratory concordance in the Euradrenal International Serum Exchange Program
- 2015
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 53:11, s. 1761-1770
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Tidskriftsartikel (refereegranskat)abstract
- Background: 21-Hydroxylase autoantibodies (21OHAb) are markers of an adrenal autoimmune process that identifies individuals with autoimmune Addison's disease (AAD). Quality and inter-laboratory agreement of various 21OHAb tests are incompletely known. The objective of the study was to determine inter-laboratory concordance for 21OHAb determinations. Methods: Sixty-nine sera from 51 patients with AAD and 51 sera from 51 healthy subjects were blindly coded by a randomization center and distributed to 14 laboratories that determined 21OHAb, either by an "in-house" assay (n=9) using in vitro-translated S-35-21OH or luciferase-labeled 21OH or a commercial kit with I-125-21OH (n=5). Main outcome measures were diagnostic accuracy of each participating laboratory and inter-laboratory agreement of 21OHAb assays. Results: Intra-assay coefficient of variation ranged from 2.6% to 5.3% for laboratories using the commercial kit and from 5.1% to 23% for laboratories using "in-house" assays. Diagnostic accuracy, expressed as area under ROC curve (AUC), varied from 0.625 to 0.947 with the commercial kit and from 0.562 to 0.978 with "in-house" methods. Cohen's. of inter-rater agreement was 0.603 among all 14 laboratories, 0.691 among "in-house" laboratories, and 0.502 among commercial kit users. Optimized cutoff levels, calculated on the basis of AUCs, increased the diagnostic accuracy of every laboratory (AUC >0.9 for 11/14 laboratories) and increased the Cohen's. of inter-rater agreement. Discrepancies in quantitation of 21OHAb levels among different laboratories increased with increasing autoantibody levels. Conclusions: The quality of 21OHAb analytical procedures is mainly influenced by selection of cutoff value and correct handling of assay materials. A standardization program is needed to identify common standard sera and common measuring units.
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| 3. |
- Johansson, Bente Berg, et al.
(författare)
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Nuclear import of glucokinase in pancreatic beta-cells is mediated by a nuclear localization signal and modulated by SUMOylation
- 2017
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Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 0303-7207. ; 454, s. 146-157
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Tidskriftsartikel (refereegranskat)abstract
- The localization of glucokinase in pancreatic beta-cell nuclei is a controversial issue. Although previous reports suggest such a localization, the mechanism for its import has so far not been identified. Using immunofluorescence, subcellular fractionation and mass spectrometry, we present evidence in support of glucokinase localization in beta-cell nuclei of human and mouse pancreatic sections, as well as in human and mouse isolated islets, and murine MIN6 cells. We have identified a conserved, seven-residue nuclear localization signal (30LKKVMRR36) in the human enzyme. Substituting the residues KK31,32 and RR35,36 with AA led to a loss of its nuclear localization in transfected cells. Furthermore, our data indicates that SUMOylation of glucokinase modulates its nuclear import, while high glucose concentrations do not significantly alter the enzyme nuclear/cytosolic ratio. Thus, for the first time, we provide data in support of a nuclear import of glucokinase mediated by a redundant mechanism, involving a nuclear localization signal, and which is modulated by its SUMOylation. These findings add new knowledge to the functional role of glucokinase in the pancreatic beta-cell.
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| 4. |
- McCulloch, Laura J, et al.
(författare)
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COL6A3 is regulated by leptin in human adipose tissue and reduced in obesity.
- 2015
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 156:1, s. 134-46
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Tidskriftsartikel (refereegranskat)abstract
- Fibrosis of adipose tissue (AT) increases AT rigidity, reduces its expandability and contributes to metabolic dysfunction. Collagen type VI, alpha3 (COL6A3) encodes one subunit of a fibrotic extracellular matrix (ECM) protein highly expressed in rodent AT. Knock-out of collagen VI in rodent AT led to a significant improvement in metabolic health in obese, diabetic (ob/ob) mice however, it is unknown whether this collagen has the same metabolic significance in human AT. We therefore aimed to undertake a comprehensive assessment of COL6A3 in relation to human AT and obesity. Characterisation of COL6A3 in human AT showed 5 fold higher expression in the stromalvascular fraction compared with adipocyte expression and significantly higher expression in subcutaneous than omental AT. In both depots COL6A3 expression appeared to be lowered in obesity, whilst diet and surgery-induced weight loss increased COL6A3 expression in subcutaneous AT. Leptin treatment caused a dose dependent decrease in COL6A3 expression although no effect was seen with insulin or glucose treatment and no difference observed in subjects with diabetes. In addition, we found that the collagen expression profile in humans differs significantly from rodents as COL6A3 does not appear to be the predominant collagen in adipose, muscle or liver. Our findings oppose those initially seen in rodent studies and most importantly, demonstrate a direct regulation of COL6A3 by leptin. This highlights the importance of a paracrine leptin signalling pathway in human AT and suggests an additional mechanism by which leptin can regulate ECM composition and with it AT expandability.
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| 5. |
- Schmedes, Mette, et al.
(författare)
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The effect of lean-seafood and non-seafood diets on fasting and postprandial serum metabolites and lipid species : Results from a randomized crossover intervention study in healthy adults
- 2018
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- The metabolic effects associated with intake of different dietary protein sources are not well characterized. We aimed to elucidate how two diets that varied in main protein sources affected the fasting and postprandial serum metabolites and lipid species. In a randomized controlled trial with crossover design, healthy adults (n = 20) underwent a 4-week intervention with two balanced diets that varied mainly in protein source (lean-seafood versus non-seafood proteins). Nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry analyses were applied to examine the effects of the two diets on serum metabolites. In the fasting state, the lean-seafood diet period, as opposed to the non-seafood diet period, significantly decreased the serum levels of isoleucine and valine, and during the postprandial state, a decreased level of lactate and increased levels of citrate and trimethylamine N-oxide were observed. The non-seafood diet significantly increased the fasting level of 26 lipid species including ceramides 18:1/14:0 and 18:1/23:0 and lysophosphatidylcholines 20:4 and 22:5, as compared to the lean-seafood diet. Thus, the lean-seafood diet decreased circulating isoleucine and valine levels, whereas the non-seafood diet elevated the levels of certain ceramides, metabolites that are associated with insulin-resistance.
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| 6. |
- Ueland, Grethe Å., et al.
(författare)
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The Short Cosyntropin Test Revisited : New Normal Reference Range Using LC-MS/MS
- 2018
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : Oxford University Press. - 0021-972X .- 1945-7197. ; 103:4, s. 1696-1703
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Tidskriftsartikel (refereegranskat)abstract
- Background: The cosyntropin test is used to diagnose adrenal insufficiency (AI) and nonclassical congenital adrenal hyperplasia (NCCAH). Current cutoffs for cortisol and 17-hydroxyprogesterone (17-OHP) are derived from nonstandardized immunoassays. Liquid chromatography tandem mass spectrometry (LC-MS/MS) offers direct measurement of steroids, prompting the need to re-establish normal ranges. Objective: The goal of this study was to define cutoff values for cortisol and 17-OHP in serum by LC-MS/MS 30 and 60 minutes after intravenous administration of 250 µg tetracosactide acetate to healthy volunteers and to compare the results with LC-MS/MS with routine immunoassays. Methods: Cosyntropin testing was performed in healthy subjects (n = 138) and in patients referred for evaluation of adrenocortical function (n = 94). Steroids were assayed by LC-MS/MS and compared with two immunoassays used in routine diagnostics (Immulite and Roche platforms). The cutoff level for cortisol was defined as the 2.5% percentile in healthy subjects not using oral estrogens (n = 121) and for 17-OHP as the 97.5% percentile. Results: Cortisol cutoff levels for LC-MS/MS were 412 and 485 nmol/L at 30 and 60 minutes, respectively. Applying the new cutoffs, 13 of 60 (22%) subjects who had AI according to conventional criteria now had a normal test result. For 17-OHP, the cutoff levels were 8.9 and 9.0 nmol/L at 30 and 60 minutes, respectively. Conclusions: LC-MS/MS provides cutoff levels for cortisol and 17-OHP after cosyntropin stimulation that are lower than those based on immunoassays, possibly because cross-reactivity between steroid intermediates and cortisol is eliminated. This reduces the number of false-positive tests for AI and false-negative tests for NCCAH.
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