Synthetic glucocorticoids are clinically used to treat auto-immune and inflammatory disease. Despite the high efficacy, glucocorticoid treatments causes side effects such as obesity and insulin... Show moreSynthetic glucocorticoids are clinically used to treat auto-immune and inflammatory disease. Despite the high efficacy, glucocorticoid treatments causes side effects such as obesity and insulin resistance in many patients. Via their pharmacological target, the glucocorticoid receptor (GR), glucocorticoids suppress endogenous glucocorticoid secretion. Endogenous, but not synthetic, glucocorticoids activate the mineralocorticoid receptor (MR) and side effects of synthetic glucocorticoids may thus not only result from GR hyperactivation but also from MR hypoactivation. Here, we tested the hypothesis that reactivation of MR with corticosterone add-on treatment can attenuate the metabolic effects of the synthetic glucocorticoid dexamethasone. Male 8-week-old C57Bl/6J mice received a high-fat diet supplemented with dexamethasone or vehicle, and were subcutaneously implanted with low-dose corticosterone- or vehicle-containing pellets. Dexamethasone strongly reduced body weight and fat mass gain, while corticosterone add-on partially normalized this. Dexamethasone-induced hyperglycemia and hyperinsulinemia were exacerbated by corticosterone add-on, which was prevented by MR antagonism. In subcutaneous white adipose tissue, corticosterone add-on prevented the dexamethasone-induced expression of intracellular lipolysis genes. In brown adipose tissue, dexamethasone also upregulated gene expression of brown adipose tissue identity markers, lipid transporters and lipolysis enzymes, which was prevented by corticosterone add-on. In conclusion, corticosterone add-on treatment prevents several, while exacerbating other metabolic effects of dexamethasone. While the exact role of MR remains elusive, this study suggests that corticosterone suppression by dexamethasone contributes to its effects in mice. Show less
Kroon, J.; Viho, E.M.G.; Gentenaar, M.; Koorneef, L.L.; Kooten, C. van; Rensen, P.C.N.; ... ; Meijer, O.C. 2021
Glucocorticoids regulate numerous processes in human physiology, but deregulated or excessive glucocorticoid receptor (GR) signaling contributes to the development of various pathologies including... Show moreGlucocorticoids regulate numerous processes in human physiology, but deregulated or excessive glucocorticoid receptor (GR) signaling contributes to the development of various pathologies including metabolic syndrome. For this reason, GR antagonists have considerable therapeutic value. Yet, the only GR antagonist that is clinically approved to date - mifepristone - exhibits cross-reactivity with other nuclear steroid receptors like the progesterone receptor. In this study, we set out to identify novel selective GR antagonists by combining rational chemical design with an unbiased in vitro and in vivo screening approach. Using this pipeline, we were able to identify CORT125329 as the compound with the best overall profile from our octahydro series of novel GR antagonists, and demonstrated that CORT125329 does not exhibit cross-reactivity with the progesterone receptor. Further in vivo testing showed beneficial activities of CORT125329 in models for excessive corticosterone exposure and short- and long-term high-fat diet-induced metabolic complications. Upon CORT125329 treatment, most metabolic parameters that deteriorated upon high-fat diet feeding were similarly improved in male and female mice, confirming activity in both sexes. However, some sexually dimorphic effects were observed including male-specific antagonism of GR activity in brown adipose tissue and female-specific lipid lowering activities after short-term CORT125329 treatment. Remarkably, CORT125329 exhibits beneficial metabolic effects despite its lack of GR antagonism in white adipose tissue. Rather, we propose that CORT125329 treatment restores metabolic activity in brown adipose tissue by stimulating lipolysis, mitochondrial activity and thermogenic capacity. In summary, we have identified CORT125329 as a selective GR antagonist with strong beneficial activities in metabolic disease models, paving the way for further clinical investigation. Show less
Janssen, L.G.M.; Nahon, K.J.; Bracke, K.F.M.; Broek, D. van den; Smit, R.; Mishre, A.S.D.S.; ... ; Rensen, P.C.N. 2020
Aims/hypothesis: Brown adipose tissue (BAT) improves energy metabolism by combusting glucose and lipids into heat. Agonism of the glucagon-like peptide-1 receptor (GLP-1R) within the central... Show moreAims/hypothesis: Brown adipose tissue (BAT) improves energy metabolism by combusting glucose and lipids into heat. Agonism of the glucagon-like peptide-1 receptor (GLP-1R) within the central nervous system activates BAT in mice. Moreover, in patients with type 2 diabetes, GLP-1R agonism lowers body weight and improves glucose and lipid levels, possibly involving BAT activation. Interestingly, people from South Asian descent are prone to develop cardiometabolic disease. We studied the effect of GLP-1R agonism on BAT in humans, specifically in South Asians and Europids without obesity or type 2 diabetes.Methods: Twelve Dutch South Asian and 12 age- and BMI-matched Europid nondiabetic men received 12 weeks extended-release exenatide (Bydureon) in this single-arm prospective study. Before and after treatment, BAT was visualized by a cold-induced [F-18]FDG-PET/CT scan and a thermoneutral MRI scan, and resting energy expenditure (REE), substrate oxidation, body composition and fasting plasma glucose and serum lipids were determined. Appetite was rated using a visual analogue scale.Results: Since the effect of exenatide onmetabolic parameters did not evidently differ between ethnicities, data of all participants were pooled. Exenatide decreased bodyweight (-1.5 +/- 0.4 kg, p < 0.01), without affecting REE or substrate oxidation, and transiently decreased appetite ratings during the first weeks. Exenatide also lowered tri-glycerides (-15%, p < 0.05) and total cholesterol (-5%, p < 0.05), and tended to lower glucose levels. Notably, exenatide increased BAT metabolic volume (+28%, p < 0.05) and mean standardized uptake value (+11%, p < 0.05) ([F-18]FDG-PET/CT), without affecting supraclavicular adipose tissue fat fraction (MRI).Conclusions/interpretation: We show for the first time that GLP-1R agonism increases [F-18]FDG uptake by BAT in South Asian and Europid men without obesity or type 2 diabetes. (C) 2020 Elsevier Inc. All rights reserved. Show less
Kroon, J.; Schilperoort, M.; Panhuis, W.I.H.; Berg, R. van den; Doeselaar, L. van; Verzijl, C.R.C.; ... ; Kooijman, S. 2020
Objective: Brown adipose tissue (BAT) displays a strong circadian rhythm in metabolic activity, but it is unclear how this rhythm is regulated. As circulating levels of corticosterone coincide with... Show moreObjective: Brown adipose tissue (BAT) displays a strong circadian rhythm in metabolic activity, but it is unclear how this rhythm is regulated. As circulating levels of corticosterone coincide with the rhythm of triglyceride-derived fatty acid (FA) uptake by BAT, we investigated whether corticosterone regulates BAT circadian rhythm.Methods: Corticosterone levels were flattened by implanting mice with subcutaneous corticosterone-releasing pellets, resulting in constant circulating corticosterone levels.Results: Flattened corticosterone rhythm caused a complete loss of circadian rhythm in triglyceride-derived fatty acid uptake by BAT. This effect was independent of glucocorticoid receptor expression in (brown) adipocytes and was not caused by deregulation of clock gene expression or overexposure to glucocorticoids, but rather seemed mediated by reduced sympathetic innervation of BAT. In a mouse model of hyperlipidemia and metabolic syndrome, long-term experimental flattening of corticosterone -and thus rhythm in BAT function -resulted in adiposity.Conclusions: This study highlights that a physiological rhythm in glucocorticoids is an important regulator of BAT function and essential for the maintenance of metabolic health.(c) 2021 The Author(s). Published by Elsevier GmbH. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Medication for nonalcoholic fatty liver disease (NAFLD) is an unmet need. Glucocorticoid (GC) stress hormones drive fat metabolism in the liver, but both full blockade and full stimulation of GC... Show moreMedication for nonalcoholic fatty liver disease (NAFLD) is an unmet need. Glucocorticoid (GC) stress hormones drive fat metabolism in the liver, but both full blockade and full stimulation of GC signaling aggravate NAFLD pathology. We investigated the efficacy of selective glucocorticoid receptor (GR) modulator CORT118335, which recapitulates only a subset of GC actions, in reducing liver lipid accumulation in mice. Male C57BL/6J mice received a low-fat diet or high-fat diet mixed with vehicle or CORT118335. Livers were analyzed histologically and for genome-wide mRNA expression. Functionally, hepatic long-chain fatty acid (LCFA) composition was determined by gas chromatography. We determined very-low-density lipoprotein (VLDL) production by treatment with a lipoprotein lipase inhibitor after which blood was collected to isolate radiolabeled VLDL particles and apoB proteins. CORT118335 strongly prevented and reversed hepatic lipid accumulation. Liver transcriptome analysis showed increased expression of GR target genes involved in VLDL production. Accordingly, CORT118335 led to increased lipidation of VLDL particles, mimicking physiological GC action. Independent pathway analysis revealed that CORT118335 lacked induction of GC-responsive genes involved in cholesterol synthesis and LCFA uptake, which was indeed reflected in unaltered hepatic LCFA uptake in vivo. Our data thus reveal that the robust hepatic lipid-lowering effect of CORT118335 is due to a unique combination of GR-dependent stimulation of lipid (VLDL) efflux from the liver, with a lack of stimulation of GR-dependent hepatic fatty acid uptake. Our findings firmly demonstrate the potential use of CORT118335 in the treatment of NAFLD and underscore the potential of selective GR modulation in metabolic disease. Show less
