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1.
Materials (Basel) ; 17(12)2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38930282

ABSTRACT

Amines supported on porous solid materials have a high CO2 adsorption capacity and low regeneration temperature. However, the high amine load on such substrates and the substrate itself may lead to substantial pressure drop across the reactor. Herein, we compare the CO2 adsorption capacity and pressure drop of fumed silica powder to 3D-printed monolithic fumed silica structures, both functionalized by polyethylenimine (PEI), and find a drastically reduced pressure drop for 3D-printed substrates (0.01 bar vs. 0.76 bar) in the sorption bed with equal CO2 adsorption capacity. Furthermore, the effect of 3D-printing nozzle diameter and PEI loading on the adsorption capacity are investigated and the highest capacities (2.0 mmol/g at 25 °C with 5000 ppm CO2) are achieved with 0.4 mm nozzle size and 34 wt% PEI loading. These high capacities are achieved since the 3D printing and subsequent sintering (700 °C) of monolithic samples does not compromise the surface area of the fumed silica. Finally, the comparison between 3D-printed monoliths and extruded granulate of varying diameter reveals that the ordered channel system of 3D-printed structures is superior to randomly oriented granulate in terms of CO2 adsorption capacity.

2.
Biochim Biophys Acta Mol Basis Dis ; 1870(5): 167175, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38626828

ABSTRACT

Loss of prolyl endopeptidase-like (PREPL) encoding a serine hydrolase with (thio)esterase activity leads to the recessive metabolic disorder Congenital Myasthenic Syndrome-22 (CMS22). It is characterized by severe neonatal hypotonia, feeding problems, growth retardation, and hyperphagia leading to rapid weight gain later in childhood. The phenotypic similarities with Prader-Willi syndrome (PWS) are striking, suggesting that similar pathways are affected. The aim of this study was to identify changes in the hypothalamic-pituitary axis in mouse models for both disorders and to examine mitochondrial function in skin fibroblasts of patients and knockout cell lines. We have demonstrated that Prepl is downregulated in the brains of neonatal PWS-IC-p/+m mice. In addition, the hypothalamic-pituitary axis is similarly affected in both Prepl-/- and PWS-IC-p/+m mice resulting in defective orexigenic signaling and growth retardation. Furthermore, we demonstrated that mitochondrial function is altered in PREPL knockout HEK293T cells and can be rescued with the supplementation of coenzyme Q10. Finally, PREPL-deficient and PWS patient skin fibroblasts display defective mitochondrial bioenergetics. The mitochondrial dysfunction in PWS fibroblasts can be rescued by overexpression of PREPL. In conclusion, we provide the first molecular parallels between CMS22 and PWS, raising the possibility that PREPL substrates might become therapeutic targets for treating both disorders.


Subject(s)
Mice, Knockout , Myasthenic Syndromes, Congenital , Prader-Willi Syndrome , Prolyl Oligopeptidases , Animals , Humans , Prader-Willi Syndrome/metabolism , Prader-Willi Syndrome/genetics , Prader-Willi Syndrome/pathology , Mice , Myasthenic Syndromes, Congenital/genetics , Myasthenic Syndromes, Congenital/metabolism , Myasthenic Syndromes, Congenital/pathology , HEK293 Cells , Prolyl Oligopeptidases/metabolism , Fibroblasts/metabolism , Fibroblasts/pathology , Mitochondria/metabolism , Mitochondria/pathology , Mitochondria/genetics , Metabolic Networks and Pathways/genetics , Disease Models, Animal , Ubiquinone/analogs & derivatives , Ubiquinone/metabolism , Serine Endopeptidases/metabolism , Serine Endopeptidases/genetics , Male , Female
3.
STAR Protoc ; 4(4): 102664, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37889759

ABSTRACT

Diabetes mellitus is a disease of the hormone-secreting endocrine pancreas. However, increasing evidence suggests that the exocrine pancreas is also involved in the pathogenesis of diabetes. In this protocol, we describe how to harvest both isolated islets and exocrine tissue from one mouse pancreas, followed by a detailed explanation of how to isolate and analyze immune cells using full-spectrum flow cytometry.


Subject(s)
Islets of Langerhans , Pancreas, Exocrine , Mice , Animals , Flow Cytometry
4.
Diabetologia ; 66(12): 2292-2306, 2023 12.
Article in English | MEDLINE | ID: mdl-37792013

ABSTRACT

AIMS/HYPOTHESIS: Colony stimulating factor 1 (CSF1) promotes the proliferation, differentiation and survival of macrophages, which have been implicated in both beneficial and detrimental effects on glucose metabolism. However, the physiological role of CSF1 signalling in glucose homeostasis and the potential therapeutic implications of modulating this pathway are not known. We aimed to study the composition of tissue macrophages (and other immune cells) following CSF1 receptor (CSF1R) inhibition and elucidate the metabolic consequences of CSF1R inhibition. METHODS: We assessed immune cell populations in various organs by flow cytometry, and tissue-specific metabolic effects by hyperinsulinaemic-euglycaemic clamps and insulin secretion assays in mice fed a chow diet containing PLX5622 (a CSF1R inhibitor) or a control diet. RESULTS: CSF1R inhibition depleted macrophages in multiple tissues while simultaneously increasing eosinophils and group 2 innate lymphoid cells. These immunological changes were consistent across different organs and were sex independent and reversible after cessation of the PLX5622. CSF1R inhibition improved hepatic insulin sensitivity but concomitantly impaired insulin secretion. In healthy islets, we found a high frequency of IL-1ß+ islet macrophages. Their depletion by CSF1R inhibition led to downregulation of macrophage-related pathways and mediators of cytokine activity, including Nlrp3, suggesting IL-1ß as a candidate insulin secretagogue. Partial restoration of physiological insulin secretion was achieved by injecting recombinant IL-1ß prior to glucose stimulation in mice lacking macrophages. CONCLUSIONS/INTERPRETATION: Macrophages and macrophage-derived factors, such as IL-1ß, play an important role in physiological insulin secretion. A better understanding of the tissue-specific effects of CSF1R inhibition on immune cells and glucose homeostasis is crucial for the development of targeted immune-modulatory treatments in metabolic disease. DATA AVAILABILITY: The RNA-Seq dataset is available in the Gene Expression Omnibus (GEO) under the accession number GSE189434 ( http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE189434 ).


Subject(s)
Immunity, Innate , Lymphocytes , Mice , Animals , Macrophages/metabolism , Glucose/metabolism
5.
PLoS One ; 18(10): e0291950, 2023.
Article in English | MEDLINE | ID: mdl-37792774

ABSTRACT

System xc-, encoded by Slc7a11, is an antiporter responsible for exporting glutamate while importing cystine, which is essential for protein synthesis and the formation of thiol peptides, such as glutathione. Glutathione acts as a co-factor for enzymes responsible for scavenging reactive oxygen species. Upon exposure to bacterial products, macrophages exhibit a rapid upregulation of system xc-. This study investigates the impact of Slc7a11 deficiency on the functionality of peritoneal and bone marrow-derived macrophages. Our findings reveal that the absence of Slc7a11 results in significantly reduced glutathione levels, compromised mitochondrial flexibility, and hindered cytokine production in bone marrow-derived macrophages. Conversely, system xc- has a lesser impact on peritoneal macrophages in vivo. These results indicate that system xc- is essential for maintaining glutathione levels, mitochondrial functionality, and cytokine production, with a heightened importance under atmospheric oxygen tension.


Subject(s)
Cystine , Glutamic Acid , Glutamic Acid/metabolism , Cystine/metabolism , Antiporters , Macrophages, Peritoneal/metabolism , Glutathione/metabolism , Cytokines/metabolism , Amino Acid Transport System y+/genetics , Amino Acid Transport System y+/metabolism
6.
Diabetologia ; 66(11): 2062-2074, 2023 11.
Article in English | MEDLINE | ID: mdl-37650924

ABSTRACT

AIMS/HYPOTHESIS: Glutamate-induced cytotoxicity (excitotoxicity) has been detected in pancreatic beta cells. The cystine/glutamate antiporter System xc- exports glutamate to the extracellular space and is therefore implicated as driving excitotoxicity. As of yet, it has not been investigated whether System xc- contributes to pancreatic islet function. METHODS: This study describes the implications of deficiency of System xc- on glucose metabolism in both constitutive and myeloid cell-specific knockout mice using metabolic tests and diet-induced obesity. Pancreatic islets were isolated and analysed for beta cell function, glutathione levels and ER stress. RESULTS: Constitutive System xc- deficiency led to an approximately threefold decrease in glutathione levels in the pancreatic islets as well as cystine shortage characterised by upregulation of Chac1. This shortage further manifested as downregulation of beta cell identity genes and a tonic increase in endoplasmic reticulum stress markers, which resulted in diminished insulin secretion both in vitro and in vivo. Myeloid-specific deletion did not have a significant impact on metabolism or islet function. CONCLUSIONS/INTERPRETATION: These findings suggest that System xc- is required for glutathione maintenance and insulin production in beta cells and that the system is dispensable for islet macrophage function.


Subject(s)
Cystine , Glutamic Acid , Mice , Animals , Cystine/metabolism , Glutamic Acid/metabolism , Insulin Secretion , Antiporters/metabolism , Mice, Knockout , Glutathione/metabolism
7.
Part Fibre Toxicol ; 20(1): 25, 2023 07 03.
Article in English | MEDLINE | ID: mdl-37400850

ABSTRACT

BACKGROUND: We previously found that air pollution particles reaching the gastrointestinal tract elicit gut inflammation as shown by up-regulated gene expression of pro-inflammatory cytokines and monocyte/macrophage markers. This inflammatory response was associated with beta-cell dysfunction and glucose intolerance. So far, it remains unclear whether gut inflammatory changes upon oral air pollution exposure are causally linked to the development of diabetes. Hence, our aim was to assess the role of immune cells in mediating glucose intolerance instigated by orally administered air pollutants. METHODS: To assess immune-mediated mechanisms underlying air pollution-induced glucose intolerance, we administered diesel exhaust particles (DEP; NIST 1650b, 12 µg five days/week) or phosphate-buffered saline (PBS) via gavage for up to 10 months to wild-type mice and mice with genetic or pharmacological depletion of innate or adaptive immune cells. We performed unbiased RNA-sequencing of intestinal macrophages to elucidate signaling pathways that could be pharmacologically targeted and applied an in vitro approach to confirm these pathways. RESULTS: Oral exposure to air pollution particles induced an interferon and inflammatory signature in colon macrophages together with a decrease of CCR2- anti-inflammatory/resident macrophages. Depletion of macrophages, NLRP3 or IL-1ß protected mice from air pollution-induced glucose intolerance. On the contrary, Rag2-/- mice lacking adaptive immune cells developed pronounced gut inflammation and glucose intolerance upon oral DEP exposure. CONCLUSION: In mice, oral exposure to air pollution particles triggers an immune-mediated response in intestinal macrophages that contributes to the development of a diabetes-like phenotype. These findings point towards new pharmacologic targets in diabetes instigated by air pollution particles.


Subject(s)
Glucose Intolerance , Vehicle Emissions , Mice , Animals , Vehicle Emissions/toxicity , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Glucose Intolerance/chemically induced , Inflammation , Immunity, Innate
8.
Part Fibre Toxicol ; 20(1): 7, 2023 03 09.
Article in English | MEDLINE | ID: mdl-36895000

ABSTRACT

BACKGROUND: Air pollution has emerged as an unexpected risk factor for diabetes. However, the mechanism behind remains ill-defined. So far, the lung has been considered as the main target organ of air pollution. In contrast, the gut has received little scientific attention. Since air pollution particles can reach the gut after mucociliary clearance from the lungs and through contaminated food, our aim was to assess whether exposure deposition of air pollution particles in the lung or the gut drive metabolic dysfunction in mice. METHODS: To study the effects of gut versus lung exposure, we exposed mice on standard diet to diesel exhaust particles (DEP; NIST 1650b), particulate matter (PM; NIST 1649b) or phosphate-buffered saline by either intratracheal instillation (30 µg 2 days/week) or gavage (12 µg 5 days/week) over at least 3 months (total dose of 60 µg/week for both administration routes, equivalent to a daily inhalation exposure in humans of 160 µg/m3 PM2.5) and monitored metabolic parameters and tissue changes. Additionally, we tested the impact of the exposure route in a "prestressed" condition (high-fat diet (HFD) and streptozotocin (STZ)). RESULTS: Mice on standard diet exposed to particulate air pollutants by intratracheal instillation developed lung inflammation. While both lung and gut exposure resulted in increased liver lipids, glucose intolerance and impaired insulin secretion was only observed in mice exposed to particles by gavage. Gavage with DEP created an inflammatory milieu in the gut as shown by up-regulated gene expression of pro-inflammatory cytokines and monocyte/macrophage markers. In contrast, liver and adipose inflammation markers were not increased. Beta-cell secretory capacity was impaired on a functional level, most likely induced by the inflammatory milieu in the gut, and not due to beta-cell loss. The differential metabolic effects of lung and gut exposures were confirmed in a "prestressed" HFD/STZ model. CONCLUSIONS: We conclude that separate lung and gut exposures to air pollution particles lead to distinct metabolic outcomes in mice. Both exposure routes elevate liver lipids, while gut exposure to particulate air pollutants specifically impairs beta-cell secretory capacity, potentially instigated by an inflammatory milieu in the gut.


Subject(s)
Air Pollutants , Air Pollution , Humans , Mice , Animals , Air Pollutants/toxicity , Air Pollutants/analysis , Lung , Particulate Matter/toxicity , Vehicle Emissions/toxicity , Lipids
10.
ACS Omega ; 7(44): 39520-39530, 2022 Nov 08.
Article in English | MEDLINE | ID: mdl-36385890

ABSTRACT

CO2 capture from industry sectors or directly from the atmosphere is drawing much attention on a global scale because of the drastic changes in the climate and ecosystem which pose a potential threat to human health and life on Earth. In the past decades, CO2 capture technology relied on classical liquid amine scrubbing. Due to its high energy consumption and corrosive property, CO2 capture using solid materials has recently come under the spotlight. A variety of porous solid materials were reported such as zeolites and metal-organic frameworks. However, amine-functionalized porous materials outperform all others in terms of CO2 adsorption capacity and regeneration efficiency. This review provides a brief overview of CO2 capture by various amines and mechanistic aspects for newcomers entering into this field. This review also covers a state-of-the-art regeneration method, visible/UV light-triggered CO2 desorption at room temperature. In the last section, the current issues and future perspectives are summarized.

11.
Nat Commun ; 13(1): 4761, 2022 08 13.
Article in English | MEDLINE | ID: mdl-35963866

ABSTRACT

Defective insulin processing is associated with obesity and diabetes. Prohormone convertase 1/3 (PC1/3) is an endopeptidase required for the processing of neurotransmitters and hormones. PC1/3 deficiency and genome-wide association studies relate PC1/3 with early onset obesity. Here, we find that deletion of PC1/3 in obesity-related neuronal cells expressing proopiomelanocortin mildly and transiently change body weight and fail to produce a phenotype when targeted to Agouti-related peptide- or nestin-expressing tissues. In contrast, pancreatic ß cell-specific PC1/3 ablation induces hyperphagia with consecutive obesity despite uncontrolled diabetes with glucosuria. Obesity develops not due to impaired pro-islet amyloid polypeptide processing but due to impaired insulin maturation. Proinsulin crosses the blood-brain-barrier but does not induce central satiety. Accordingly, insulin therapy prevents hyperphagia. Further, islet PC1/3 expression levels negatively correlate with body mass index in humans. In this work, we show that impaired PC1/3-mediated proinsulin processing, as observed in human prediabetes, promotes hyperphagic obesity.


Subject(s)
Diabetes Mellitus , Proinsulin , Genome-Wide Association Study , Humans , Hyperphagia/genetics , Insulin/metabolism , Obesity/complications , Obesity/genetics , Obesity/metabolism , Proinsulin/genetics , Proinsulin/metabolism , Proprotein Convertase 1/genetics
12.
Cell Metab ; 34(7): 991-1003.e6, 2022 07 05.
Article in English | MEDLINE | ID: mdl-35750050

ABSTRACT

The initial cephalic phase of insulin secretion is mediated through the vagus nerve and is not due to glycemic stimulation of pancreatic ß cells. Recently, IL-1ß was shown to stimulate postprandial insulin secretion. Here, we describe that this incretin-like effect of IL-1ß involves neuronal transmission. Furthermore, we found that cephalic phase insulin release was mediated by IL-1ß originating from microglia. Moreover, IL-1ß activated the vagus nerve to induce insulin secretion and regulated the activity of the hypothalamus in response to cephalic stimulation. Notably, cephalic phase insulin release was impaired in obesity, in both mice and humans, and in mice, this was due to dysregulated IL-1ß signaling. Our findings attribute a regulatory role to IL-1ß in the integration of nutrient-derived sensory information, subsequent neuronally mediated insulin secretion, and the dysregulation of autonomic cephalic phase responses in obesity.


Subject(s)
Insulin-Secreting Cells , Insulin , Interleukin-1beta , Animals , Blood Glucose/metabolism , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/metabolism , Interleukin-1beta/metabolism , Mice , Obesity/metabolism
13.
Commun Biol ; 5(1): 370, 2022 04 19.
Article in English | MEDLINE | ID: mdl-35440795

ABSTRACT

The obesity epidemic continues to worsen worldwide. However, the mechanisms initiating glucose dysregulation in obesity remain poorly understood. We assessed the role that colonic macrophage subpopulations play in glucose homeostasis in mice fed a high-fat diet (HFD). Concurrent with glucose intolerance, pro-inflammatory/monocyte-derived colonic macrophages increased in mice fed a HFD. A link between macrophage numbers and glycemia was established by pharmacological dose-dependent ablation of macrophages. In particular, colon-specific macrophage depletion by intrarectal clodronate liposomes improved glucose tolerance, insulin sensitivity, and insulin secretion capacity. Colonic macrophage activation upon HFD was characterized by an interferon response and a change in mitochondrial metabolism, which converged in mTOR as a common regulator. Colon-specific mTOR inhibition reduced pro-inflammatory macrophages and ameliorated insulin secretion capacity, similar to colon-specific macrophage depletion, but did not affect insulin sensitivity. Thus, pharmacological targeting of colonic macrophages could become a potential therapy in obesity to improve glycemic control.


Subject(s)
Diet, High-Fat , Insulin Resistance , Animals , Blood Glucose/metabolism , Colon/metabolism , Diet, High-Fat/adverse effects , Glycemic Control , Macrophages/metabolism , Mice , Obesity/etiology , Obesity/metabolism , TOR Serine-Threonine Kinases/metabolism
14.
Immunity ; 55(1): 31-55, 2022 01 11.
Article in English | MEDLINE | ID: mdl-35021057

ABSTRACT

Obesity leads to chronic, systemic inflammation and can lead to insulin resistance (IR), ß-cell dysfunction, and ultimately type 2 diabetes (T2D). This chronic inflammatory state contributes to long-term complications of diabetes, including non-alcoholic fatty liver disease (NAFLD), retinopathy, cardiovascular disease, and nephropathy, and may underlie the association of type 2 diabetes with other conditions such as Alzheimer's disease, polycystic ovarian syndrome, gout, and rheumatoid arthritis. Here, we review the current understanding of the mechanisms underlying inflammation in obesity, T2D, and related disorders. We discuss how chronic tissue inflammation results in IR, impaired insulin secretion, glucose intolerance, and T2D and review the effect of inflammation on diabetic complications and on the relationship between T2D and other pathologies. In this context, we discuss current therapeutic options for the treatment of metabolic disease, advances in the clinic and the potential of immune-modulatory approaches.


Subject(s)
Diabetes Complications/immunology , Diabetes Mellitus, Type 2/immunology , Inflammation/immunology , Obesity/immunology , Animals , Humans , Immunomodulation , Insulin Resistance
15.
ESC Heart Fail ; 9(1): 66-76, 2022 02.
Article in English | MEDLINE | ID: mdl-34881523

ABSTRACT

AIMS: In acute heart failure (AHF), changes of venous haemoglobin (Hb) concentrations, haematocrit (Hct), and estimated plasma volume (ePV) have been proposed as surrogates of decongestion. These estimates are based on the theoretical assumptions that changes of Hb concentrations and Hct are driven by the intravascular volume status and that the intravascular Hb pool remains stable. The objective of this study was to assess the relationship of changes of measured plasma volume (mPV) with changes of Hb, Hct, and ePV in AHF. METHODS AND RESULTS: We studied 36 AHF patients, who received two sequential assessments of mPV, measured red cell volume (mRCV) and measured total blood volume (mTBV) (48 h apart), during the course of diuretic therapy using a novel visible fluorescent injectate (VFI) technique based on the indicator dilution principle. Changes of ePV were calculated based on the Kaplan-Hakim or Strauss formula. AHF patients receiving diuretics (median intravenous furosemide equivalent 160 mg/48 h) displayed a wide range of changes of mPV (-25.4% to +37.0%). Changes in mPV were not significantly correlated with changes of Hb concentration [Pearson's r (r) = -0.241, P = 0.157], Hct (r = -0.307, P = 0.069), ePVKaplan-Hakim (r = 0.228, P = 0.182), or ePVStrauss (r = 0.237, P = 0.163). In contrast to theoretical assumptions, changes of mTBV were poorly correlated with changes of Hb concentrations and some patients displayed unanticipated variability of mRCV, suggesting an unstable intravascular red cell pool. CONCLUSIONS: Changes of Hb or Hct were not reflective of directly measured changes of intravascular volume status in AHF patients. Basing clinical assessment of decongestion on changes of Hb or Hct may misguide clinical decision-making on an individual patient level.


Subject(s)
Heart Failure , Plasma Volume , Diuretics/therapeutic use , Furosemide , Heart Failure/therapy , Humans
16.
iScience ; 24(11): 103250, 2021 Nov 19.
Article in English | MEDLINE | ID: mdl-34746709

ABSTRACT

Aging is the prime risk factor for the development of type 2 diabetes. We investigated the role of the interleukin-1 (IL-1) system on insulin secretion in aged mice. During aging, expression of the protective IL-1 receptor antagonist decreased in islets, whereas IL-1beta gene expression increased specifically in the CD45 + islet immune cell fraction. One-year-old mice with a whole-body knockout of IL-1beta had higher insulin secretion in vivo and in isolated islets, along with enhanced proliferation marker Ki67 and elevated size and number of islets. Myeloid cell-specific IL-1beta knockout preserved glucose-stimulated insulin secretion during aging, whereas it declined in control mice. Isolated islets from aged myeloIL-1beta ko mice secreted more insulin along with increased expression of Ins2, Kir6.2, and of the cell-cycle gene E2f1. IL-1beta treatment of isolated islets reduced E2f1, Ins2, and Kir6.2 expression in beta cells. We conclude that IL-1beta contributes the age-associated decline of beta cell function.

17.
ESC Heart Fail ; 8(4): 3070-3081, 2021 08.
Article in English | MEDLINE | ID: mdl-33955699

ABSTRACT

AIMS: We aimed to test whether the endogenous filtration markers serum creatinine or cystatin C and equation-based estimates of glomerular filtration rate (GFR) based on these markers appropriately reflect changes of measured GFR in patients with acute heart failure. METHODS: In this prospective cohort study of 50 hospitalized acute heart failure patients undergoing decongestive therapy, we applied an intravenous visible fluorescent injectate (VFI), consisting of a low molecular weight component to measure GFR and a high molecular weight component to correct for measured plasma volume. Thirty-eight patients had two sequential GFR measurements 48 h apart. The co-primary endpoints of the study were safety of VFI and plasma stability of the high molecular weight component. A key secondary endpoint was to compare changes in measured GFR (mGFR) to changes of serum creatinine, cystatin C and estimated GFR. RESULTS: VFI-based GFR measurements were safe and consistent with plasma stability of the high molecular weight component and glomerular filtration of the low molecular weight component. Filtration marker-based point estimates of GFR, when compared with mGFR, provided only moderate correlation (Pearson's r, range 0.80-0.88, depending on equation used), precision (r2 , range 0.65-0.78) and accuracy (56%-74% of estimates scored within 30% of mGFR). Correlations of 48-h changes GFR estimates and changes of mGFR were significant (P < 0.05) but weak (Pearson's r, range 0.35-0.39). Observed decreases of eGFR by more than 15% had a low sensitivity (range 38%-46%, depending on equation used) in detecting true worsening mGFR, defined by a >15% decrease in mGFR. CONCLUSIONS: In patients hospitalized for acute heart failure, serum creatinine- and cystatin C-based predictions performed poorly in detecting actual changes of GFR. These data challenge current clinical strategies to evaluate dynamics of kidney function in acute heart failure.


Subject(s)
Cystatin C , Heart Failure , Creatinine , Glomerular Filtration Rate , Heart Failure/diagnosis , Humans , Prospective Studies
18.
Diabetologia ; 63(11): 2385-2395, 2020 11.
Article in English | MEDLINE | ID: mdl-32728889

ABSTRACT

AIMS/HYPOTHESIS: Aggregation of the beta cell secretory product human islet amyloid polypeptide (hIAPP) results in islet amyloid deposition, a pathological feature of type 2 diabetes. Amyloid formation is associated with increased levels of islet IL-1ß as well as beta cell dysfunction and death, but the mechanisms that promote amyloid deposition in situ remain unclear. We hypothesised that physiologically relevant concentrations of IL-1ß stimulate beta cell islet amyloid polypeptide (IAPP) release and promote amyloid formation. METHODS: We used a humanised mouse model of endogenous beta cell hIAPP expression to examine whether low (pg/ml) concentrations of IL-1ß promote islet amyloid formation in vitro. Amyloid-forming islets were cultured for 48 h in the presence or absence of IL-1ß with or without an IL-1ß neutralising antibody. Islet morphology was assessed by immunohistochemistry and islet mRNA expression, hormone content and release were also quantified. Cell-free thioflavin T assays were used to monitor hIAPP aggregation kinetics in the presence and absence of IL-1ß. RESULTS: Treatment with a low concentration of IL-1ß (4 pg/ml) for 48 h increased islet amyloid prevalence (93.52 ± 3.89% vs 43.83 ± 9.67% amyloid-containing islets) and amyloid severity (4.45 ± 0.82% vs 2.16 ± 0.50% amyloid area/islet area) in hIAPP-expressing mouse islets in vitro. This effect of IL-1ß was reduced when hIAPP-expressing islets were co-treated with an IL-1ß neutralising antibody. Cell-free hIAPP aggregation assays showed no effect of IL-1ß on hIAPP aggregation in vitro. Low concentration IL-1ß did not increase markers of the unfolded protein response (Atf4, Ddit3) or alter proIAPP processing enzyme gene expression (Pcsk1, Pcsk2, Cpe) in hIAPP-expressing islets. However, release of IAPP and insulin were increased over 48 h in IL-1ß-treated vs control islets (IAPP 0.409 ± 0.082 vs 0.165 ± 0.051 pmol/5 islets; insulin 87.5 ± 8.81 vs 48.3 ± 17.3 pmol/5 islets), and this effect was blocked by co-treatment with IL-1ß neutralising antibody. CONCLUSIONS/INTERPRETATION: Under amyloidogenic conditions, physiologically relevant levels of IL-1ß promote islet amyloid formation by increasing beta cell release of IAPP. Neutralisation of this effect of IL-1ß may decrease the deleterious effects of islet amyloid formation on beta cell function and survival.


Subject(s)
Interleukin-1beta/pharmacology , Amyloidosis/drug therapy , Animals , Humans , Insulin/metabolism , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Islet Amyloid Polypeptide/metabolism , Mice
19.
Sci Rep ; 10(1): 3035, 2020 02 20.
Article in English | MEDLINE | ID: mdl-32080229

ABSTRACT

Gestational diabetes mellitus (GDM) is one of the most common diseases associated with pregnancy, however, the underlying mechanisms remain unclear. Based on the well documented role of inflammation in type 2 diabetes, the aim was to investigate the role of inflammation in GDM. We established a mouse model for GDM on the basis of its two major risk factors, obesity and aging. In these GDM mice, we observed increased Interleukin-1ß (IL-1ß) expression in the uterus and the placenta along with elevated circulating IL-1ß concentrations compared to normoglycemic pregnant mice. Treatment with an anti-IL-1ß antibody improved glucose-tolerance of GDM mice without apparent deleterious effects for the fetus. Finally, IL-1ß antagonism showed a tendency for reduced plasma corticosterone concentrations, possibly explaining the metabolic improvement. We conclude that IL-1ß is a causal driver of impaired glucose tolerance in GDM.


Subject(s)
Diabetes, Gestational/metabolism , Hyperglycemia/complications , Hyperglycemia/metabolism , Interleukin-1beta/antagonists & inhibitors , Animals , Diabetes, Gestational/blood , Disease Models, Animal , Female , Hormones/blood , Hyperglycemia/blood , Interleukin-1beta/metabolism , Mice, Inbred C57BL , Pregnancy , Steroids/blood
20.
Endocr Rev ; 40(4): 1080-1091, 2019 08 01.
Article in English | MEDLINE | ID: mdl-31127805

ABSTRACT

The role of chronic inflammation in the pathogenesis of type 2 diabetes mellitus and associated complications is now well established. Therapeutic interventions counteracting metabolic inflammation improve insulin secretion and action and glucose control and may prevent long-term complications. Thus, a number of anti-inflammatory drugs approved for the treatment of other inflammatory conditions are evaluated in patients with metabolic syndrome. Most advanced are clinical studies with IL-1 antagonists showing improved ß-cell function and glycemia and prevention of cardiovascular diseases and heart failure. However, alternative anti-inflammatory treatments, alone or in combinations, may turn out to be more effective, depending on genetic predispositions, duration, and manifestation of the disease. Thus, there is a great need for comprehensive and well-designed clinical studies to implement anti-inflammatory drugs in the treatment of patients with metabolic syndrome and its associated conditions.


Subject(s)
Cardiovascular Diseases/physiopathology , Diabetes Mellitus, Type 2/complications , Inflammation , Animals , Cardiovascular Diseases/complications , Humans , Metabolic Syndrome
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