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1.
Article in English | MEDLINE | ID: mdl-39265079

ABSTRACT

The underlying causes of diabetic kidney disease are still largely unknown. New insights into the contributing causes of diabetic nephropathy are important in order to prevent this complication. Hyperglycemia and hypertension are some of the risk factors for diabetic nephropathy. However, the incidence of diabetic nephropathy is increasing despite efforts to normalize blood-glucose levels and blood pressure. Therefore, other factors should be investigated as causes of diabetic nephropathy. We investigated whether long-term increased plasma levels of glucagon contribute to the development of pathophysiological changes in kidney function as seen in patients with diabetic nephropathy. Using mouse models of chronic activation and inactivation of glucagon receptor signaling, we investigated whether glucagon is involved in changes in renal function, renal structural and transcriptional changes. We found several histopathological changes in the kidney, such as thickening of the parietal layer of Bowman's capsule, glomerular mesangial cell expansion, and significant albuminuria in the mice with activated glucagon receptor signaling. Opposite effects on mesangial area expansion and the development of albuminuria were demonstrated in mice with glucagon receptor inactivation. RNA sequencing data revealed that transcription of genes related to fatty acid metabolism, podocytes, Na+/K+-ATPase, and sodium/glucose transport were significantly changed in mice with activated glucagon receptor signaling. These data implicate that the glucagon receptor signaling is involved in the development of kidney injury, as seen in type 2 diabetes and that glucagon receptor is a potential therapeutic target in the treatment of diabetes.

2.
J Med Case Rep ; 18(1): 473, 2024 Sep 29.
Article in English | MEDLINE | ID: mdl-39342404

ABSTRACT

BACKGROUND: Plasma levels of D-dimer are elevated in patients with thromboembolisms. Here we investigated the existence of interfering antibodies as a potential cause for elevated D-dimer levels. CASE PRESENTATION: A 42-year-old white Caucasian woman with a prior history of pulmonary embolism during her first pregnancy (treated with heparin therapy for 6 weeks postnatally) and hypothyroidism had a persistent elevated D-dimer without any clinical or ultrasound-based signs of thromboembolic conditions during her second pregnancy. We obtained informed consent and plasma was obtained from the patient. D-dimer levels were measured using two different assays. We also tested for the presence of rheumatoid factor, performed dilution series, and finally used an antibody depletion strategy. The two D-dimer assays performed similarly. Using our antibody depletion technique, we observed that ~ 1/3 of the increased plasma levels of D-dimer may be attributed to interfering antibodies. CONCLUSIONS: Our results identify interfering antibodies as a potential contributor to an increased D-dimer in this patient. Our case highlights the potential of heterophilic interference for increased D-dimer and provides a procedure to determine this analytically.


Subject(s)
Fibrin Fibrinogen Degradation Products , Pulmonary Embolism , Humans , Fibrin Fibrinogen Degradation Products/analysis , Female , Adult , Pregnancy , Pulmonary Embolism/diagnostic imaging , Pulmonary Embolism/blood , Hypothyroidism/blood , Hypothyroidism/drug therapy , Hypothyroidism/immunology , Hypothyroidism/diagnosis
3.
Am J Physiol Gastrointest Liver Physiol ; 327(4): G558-G570, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39104323

ABSTRACT

Increased plasma concentrations of glucagon (hyperglucagonemia) are reported in patients with type 2 diabetes (T2D) and are considered a diabetogenic risk factor. Emerging evidence suggests that hepatic steatosis in obesity is causing a condition of resistance toward glucagon's effects on amino acid metabolism, resulting in an amino acid-induced hyperglucagonemia. We investigated the presence of hyperglucagonemia in individuals with biopsy-verified metabolic dysfunction-associated steatotic liver disease (MASLD), and whether body mass index (BMI), T2D, hepatic steatosis, and/or fibrosis contribute to this relationship. To dissect potential mechanisms, we also determined hepatic gene expression related to amino acid transport and catabolism. Individuals with MASLD had hyperglucagonemia {controls (n = 74) vs. MASLD (n = 106); median [Q1, Q3]; 4 [3, 7] vs. 8 [6, 13] pM), P < 0.0001} and were glucagon resistant (assessed by the glucagon-alanine index) {1.3 [0.9, 2.1] vs. 3.3 [2.1, 5.3] pM·mM, P < 0.0001}. These changes were associated with hepatic steatosis (P < 0.001, R2 > 0.25) independently of BMI, sex, age, and T2D. Plasma levels of glucagon were similar in individuals with MASLD when stratified on T2D status {MASLD-T2D (n = 52) vs. MASLD + T2D (n = 54); 8 [6, 11] vs. 8 [6, 13] pM, P = 0.34} and hepatic fibrosis {MASLD + F0 (n = 25) vs. MASLD + F1-F3 (n = 67); 8.4 [7.0, 13.3] vs. 7.9 [5.2, 11.6] pM, P = 0.43}. Obesity (BMI = 30 kg/m2) did not alter glucagon levels (P = 0.65) within groups (control/MASLD). The mRNA expression of proteins involved in amino acid transport and catabolism was downregulated in MASLD. Thus, relative hyperglucagonemia is present in individuals with biopsy-verified MASLD, and hepatic steatosis partially drives hyperglucagonemia and glucagon resistance, irrespective of T2D, BMI, and hepatic fibrosis.NEW & NOTEWORTHY Individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) present with increased plasma levels of glucagon (hyperglucagonemia), irrespective of body mass index (BMI) and type 2 diabetes. Therefore, MASLD and the resultant hyperglucagonemia may act as a diabetogenic risk factor. Notably, hepatic steatosis was a significant contributor to the hyperglucagonemia in MASLD, potentially unveiling a pathway for the hyperglucagonemia in some patients with type 2 diabetes.


Subject(s)
Body Mass Index , Diabetes Mellitus, Type 2 , Fatty Liver , Glucagon , Liver Cirrhosis , Humans , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , Glucagon/blood , Male , Middle Aged , Female , Fatty Liver/blood , Liver Cirrhosis/blood , Obesity/complications , Obesity/blood , Liver/metabolism , Liver/pathology , Aged , Adult , Amino Acids/blood
4.
Eur J Endocrinol ; 191(2): 192-203, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39049802

ABSTRACT

AIMS: Although metformin is widely used for treatment of type 2 diabetes (T2D), its glucose-lowering mechanism remains unclear. Using the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) antagonist exendin(9-39)NH2, we tested the hypothesis that postprandial GLP-1-mediated effects contribute to the glucose-lowering potential of metformin in T2D. METHODS: In a randomized, placebo-controlled, double-blind, crossover study, 15 individuals with T2D (median HbA1c 50 mmol/mol [6.7%], body mass index 30.1 kg/m2, age 71 years) underwent, in randomized order, 14 days of metformin and placebo treatment, respectively. Each treatment period was preceded by 14 days without any glucose-lowering medicine and concluded by two 4 h mixed meal tests performed in randomized order and separated by >24 h with either continuous intravenous exendin(9-39)NH2 or saline infusion. RESULTS: Compared to placebo, metformin treatment lowered fasting plasma glucose (mean of differences [MD] 1.4 mmol/L × min [95% CI 0.8-2.0]) as well as postprandial plasma glucose excursions during both saline infusion (MD 186 mmol/L × min [95% CI 64-307]) and exendin(9-39)NH2 infusion (MD 268 mmol/L × min [95% CI 108-427]). The metformin-induced improvement in postprandial glucose tolerance was unaffected by GLP-1R antagonization (MD 82 mmol/L × min [95% CI -6564-170]). Metformin treatment increased fasting plasma GLP-1 (MD 1.7 pmol/L × min [95% CI 0.39-2.9]) but did not affect postprandial GLP-1 responses (MD 820 pmol/L × min [95% CI -1750-111]). CONCLUSIONS: Using GLP-1R antagonization, we could not detect GLP-1-mediated postprandial glucose-lowering effect of metformin in individuals with T2D. We show that 2 weeks of metformin treatment increases fasting plasma GLP-1, which may contribute to metformin's beneficial effect on fasting plasma glucose in T2D. Trial registration: Clinicaltrials.gov NCT03246451.


Subject(s)
Blood Glucose , Cross-Over Studies , Diabetes Mellitus, Type 2 , Glucagon-Like Peptide 1 , Hypoglycemic Agents , Metformin , Postprandial Period , Humans , Metformin/therapeutic use , Metformin/administration & dosage , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/blood , Postprandial Period/drug effects , Male , Female , Aged , Glucagon-Like Peptide 1/blood , Double-Blind Method , Blood Glucose/drug effects , Blood Glucose/metabolism , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/pharmacology , Middle Aged , Glucagon-Like Peptide-1 Receptor/agonists , Peptide Fragments
5.
Diabetes Obes Metab ; 26(9): 3926-3934, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38957925

ABSTRACT

AIM: To evaluate insulin and glucagon sensitivity in Han Chinese women with and without gestational diabetes mellitus (GDM). METHODS: In total, 81 women with GDM and 81 age-matched healthy controls were evaluated with a 75 g oral glucose tolerance test (OGTT) at gestational weeks 24-28. Plasma glucose concentrations were measured at fasting and 1 h and 2 h post-OGTT. Fasting plasma insulin, glucagon and amino acids were also measured. Insulin and glucagon sensitivity were assessed by the homeostatic model assessment of insulin resistance (HOMA-IR) and glucagon-alanine index, respectively. RESULTS: As expected, plasma glucose concentrations were higher at fasting and 1 h and 2 h post-OGTT in GDM participants (p < .001 each). Both the HOMA-IR and the glucagon-alanine index were higher in GDM participants. There was a weak positive correlation between HOMA-IR and glucagon-alanine index (r = 0.24, p = .0024). Combining the HOMA-IR and the glucagon-alanine index yielded better capacity (area under the curve = 0.878) than either alone (area under the curve = 0.828 for HOMA-IR and 0.751 for glucagon-alanine index, respectively) in differentiating GDM from healthy participants. While the majority of GDM participants (64%) exhibited both reduced insulin and glucagon sensitivity, a third of them presented either reduced insulin (20%) or glucagon (14%) sensitivity alone. HOMA-IR and glucagon-alanine index correlated differentially with fasting glucose, triglycerides, low-density lipoprotein cholesterol, sum of amino acids and hepatic steatosis index. CONCLUSIONS: Impairments of both insulin and glucagon sensitivity occur frequently in Chinese women with GDM, which may, individually or together, drive metabolic derangements in GDM. These observations provide new insights into the pathophysiology of GDM and support the need to target insulin or glucagon resistance, or both, in the management of GDM.


Subject(s)
Blood Glucose , Diabetes, Gestational , Glucagon , Glucose Tolerance Test , Insulin Resistance , Insulin , Humans , Female , Diabetes, Gestational/blood , Diabetes, Gestational/metabolism , Pregnancy , Glucagon/blood , Adult , Blood Glucose/metabolism , Blood Glucose/analysis , Insulin/blood , China/epidemiology , Asian People , Case-Control Studies , Fasting/blood , Alanine/blood , East Asian People
6.
Science ; 385(6704): 80-86, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38963846

ABSTRACT

Classical migraine patients experience aura, which is transient neurological deficits associated with cortical spreading depression (CSD), preceding headache attacks. It is not currently understood how a pathological event in cortex can affect peripheral sensory neurons. In this study, we show that cerebrospinal fluid (CSF) flows into the trigeminal ganglion, establishing nonsynaptic signaling between brain and trigeminal cells. After CSD, ~11% of the CSF proteome is altered, with up-regulation of proteins that directly activate receptors in the trigeminal ganglion. CSF collected from animals exposed to CSD activates trigeminal neurons in naïve mice in part by CSF-borne calcitonin gene-related peptide (CGRP). We identify a communication pathway between the central and peripheral nervous system that might explain the relationship between migrainous aura and headache.


Subject(s)
Calcitonin Gene-Related Peptide , Cortical Spreading Depression , Migraine Disorders , Trigeminal Ganglion , Animals , Mice , Calcitonin Gene-Related Peptide/cerebrospinal fluid , Calcitonin Gene-Related Peptide/metabolism , Cerebrospinal Fluid/metabolism , Disease Models, Animal , Migraine Disorders/cerebrospinal fluid , Migraine Disorders/metabolism , Migraine Disorders/physiopathology , Proteome/metabolism , Signal Transduction , Trigeminal Ganglion/metabolism , Trigeminal Ganglion/physiopathology
8.
Diabetes ; 73(10): 1716-1727, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38976454

ABSTRACT

Increased plasma levels of glucagon (hyperglucagonemia) promote diabetes development but are also observed in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). This may reflect hepatic glucagon resistance toward amino acid catabolism. A clinical test for measuring glucagon resistance has not been validated. We evaluated our glucagon sensitivity (GLUSENTIC) test, which consists of 2 study days: a glucagon injection and measurements of plasma amino acids and an infusion of mixed amino acids and subsequent calculation of the GLUSENTIC index (primary outcome measure) from measurements of glucagon and amino acids. To distinguish glucagon-dependent from insulin-dependent actions on amino acid metabolism, we also studied patients with type 1 diabetes (T1D). The δ-decline in total amino acids was 49% lower in MASLD following exogenous glucagon (P = 0.01), and the calculated GLUSENTIC index was 34% lower in MASLD (P < 0.0001) but not T1D (P > 0.99). In contrast, glucagon-induced glucose increments were similar in control participants and participants with MASLD (P = 0.41). The GLUSENTIC test and index may be used to measure glucagon resistance in individuals with obesity and MASLD.


Subject(s)
Fatty Liver , Glucagon , Obesity , Humans , Glucagon/blood , Male , Female , Fatty Liver/metabolism , Obesity/metabolism , Middle Aged , Adult , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/physiopathology , Amino Acids/blood , Blood Glucose/metabolism
9.
Am J Clin Nutr ; 120(2): 283-293, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38914224

ABSTRACT

BACKGROUND: Intrahepatic triacylglycerol (liver TG) content is associated with hepatic insulin resistance and dyslipidemia. Liver TG content can be modulated within days under hypocaloric conditions. OBJECTIVES: We hypothesized that 4 d of eucaloric low-carbohydrate/high-fat (LC) intake would decrease liver TG content, whereas a high-carbohydrate/low-fat (HC) intake would increase liver TG content, and further that alterations in liver TG would be linked to dynamic changes in hepatic glucose and lipid metabolism. METHODS: A randomized crossover trial in males with 4 d + 4 d of LC and HC, respectively, with ≥2 wk of washout. 1H-magnetic resonance spectroscopy (1H-MRS) was used to measure liver TG content, with metabolic testing before and after intake of an LC diet (11E% carbohydrate corresponding to 102 ± 12 {mean ± standard deviation [SD]) g/d, 70E% fat} and an HC diet (65E% carbohydrate corresponding to 537 ± 56 g/d, 16E% fat). Stable [6,6-2H2]-glucose and [1,1,2,3,3-D5]-glycerol tracer infusions combined with hyperinsulinemic-euglycemic clamps and indirect calorimetry were used to measure rates of hepatic glucose production and lipolysis, whole-body insulin sensitivity and substrate oxidation. RESULTS: Eleven normoglycemic males with overweight or obesity (BMI 31.6 ± 3.7 kg/m2) completed both diets. The LC diet reduced liver TG content by 35.3% (95% confidence interval: -46.6, -24.1) from 4.9% [2.4-11.0] (median interquartile range) to 2.9% [1.4-6.9], whereas there was no change after the HC diet. After the LC diet, fasting whole-body fat oxidation and plasma beta-hydroxybutyrate concentration increased, whereas markers of de novo lipogenesis (DNL) diminished. Fasting plasma TG and insulin concentrations were lowered and the hepatic insulin sensitivity index increased after LC. Peripheral glucose disposal was unchanged. CONCLUSIONS: Reduced carbohydrate and increased fat intake for 4 d induced a marked reduction in liver TG content and increased hepatic insulin sensitivity. Increased rates of fat oxidation and ketogenesis combined with lower rates of DNL are suggested to be responsible for lowering liver TG. This trial was registered at clinicaltrials.gov as NCT04581421.


Subject(s)
Cross-Over Studies , Liver , Obesity , Overweight , Triglycerides , Humans , Male , Triglycerides/metabolism , Liver/metabolism , Adult , Overweight/metabolism , Overweight/diet therapy , Obesity/metabolism , Obesity/diet therapy , Diet, Carbohydrate-Restricted , Dietary Carbohydrates/administration & dosage , Dietary Carbohydrates/metabolism , Young Adult , Middle Aged , Insulin Resistance
10.
Eur J Cancer ; 207: 114186, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38943900

ABSTRACT

BACKGROUND: Circulating tumor DNA (ctDNA) has emerged as a promising tool for early cancer detection and minimal residual disease monitoring. However, the biology underlying ctDNA release and its variation across cancer types and histologies remains poorly understood. This study investigated the biology behind ctDNA shedding in colorectal cancer. METHODS: The study included a local cohort of 747 stage I-III colorectal cancer patients. All patients had ctDNA measurement prior to treatment and extensive clinical data. Primary tumor RNA sequencing and whole exome sequencing was performed in 95 and 652 patients respectively. Additionally, the study evaluated 89 non-small cell lung cancer patients from the TRACERx cohort, comprising primary tumor RNA sequencing and ctDNA measurement. RESULTS: We found tumor size and proliferative capacity to be key factors associated with ctDNA shedding in colorectal cancer. Furthermore, we found that the secretory and CMS3 colorectal cancer subtypes exhibited lower ctDNA shedding, while microsatellite instability (MSI) tumors had higher levels of ctDNA. Mutational analysis did not reveal any genes or pathways associated with ctDNA shedding in colorectal cancer. A comparison of transcriptomic profiles across multiple cancer types demonstrated that colorectal cancer and lung squamous cell carcinoma tumors shared a high-proliferative ctDNA shedding phenotype, while lung adenocarcinoma tumors displayed a distinct low-proliferative subgroup. Additionally, proliferation levels correlated with ctDNA detection sensitivity across multiple cancer types. CONCLUSION: These findings suggest that tumor size and proliferative capacity are drivers of ctDNA release in colorectal cancer and provide insights into the biology of ctDNA shedding on a pan-cancer level.


Subject(s)
Biomarkers, Tumor , Circulating Tumor DNA , Colorectal Neoplasms , Humans , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Colorectal Neoplasms/blood , Circulating Tumor DNA/genetics , Circulating Tumor DNA/blood , Male , Female , Aged , Middle Aged , Biomarkers, Tumor/genetics , Biomarkers, Tumor/blood , Microsatellite Instability , Exome Sequencing , Aged, 80 and over , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Lung Neoplasms/blood , Adult
11.
Int J Mol Sci ; 25(11)2024 May 28.
Article in English | MEDLINE | ID: mdl-38892056

ABSTRACT

Desmoplasia is a common feature of aggressive cancers, driven by a complex interplay of protein production and degradation. Basigin is a type 1 integral membrane receptor secreted in exosomes or released by ectodomain shedding from the cell surface. Given that soluble basigin is increased in the circulation of patients with a poor cancer prognosis, we explored the putative role of the ADAM12-generated basigin ectodomain in cancer progression. We show that recombinant basigin ectodomain binds ß1 integrin and stimulates gelatin degradation and the migration of cancer cells in a matrix metalloproteinase (MMP)- and ß1-integrin-dependent manner. Subsequent in vitro and in vivo experiments demonstrated the altered expression of extracellular matrix proteins, including fibronectin and collagen type 5. Thus, we found increased deposits of collagen type 5 in the stroma of nude mice tumors of the human tumor cell line MCF7 expressing ADAM12-mimicking the desmoplastic response seen in human cancer. Our findings indicate a feedback loop between ADAM12 expression, basigin shedding, TGFß signaling, and extracellular matrix (ECM) remodeling, which could be a mechanism by which ADAM12-generated basigin ectodomain contributes to the regulation of desmoplasia, a key feature in human cancer progression.


Subject(s)
ADAM12 Protein , Basigin , Extracellular Matrix Proteins , Animals , Female , Humans , Mice , ADAM12 Protein/metabolism , ADAM12 Protein/genetics , Basigin/metabolism , Basigin/genetics , Cell Line, Tumor , Cell Movement , Extracellular Matrix/metabolism , Extracellular Matrix Proteins/metabolism , Gene Expression Regulation, Neoplastic , MCF-7 Cells , Mice, Nude , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/genetics , Protein Binding , Protein Domains , Integrin beta1/metabolism
12.
Commun Biol ; 7(1): 688, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38839859

ABSTRACT

Multisystem inflammatory syndrome in children (MIS-C) is a severe disease that emerged during the COVID-19 pandemic. Although recognized as an immune-mediated condition, the pathogenesis remains unresolved. Furthermore, the absence of a diagnostic test can lead to delayed immunotherapy. Using state-of-the-art mass-spectrometry proteomics, assisted by artificial intelligence (AI), we aimed to identify a diagnostic signature for MIS-C and to gain insights into disease mechanisms. We identified a highly specific 4-protein diagnostic signature in children with MIS-C. Furthermore, we identified seven clusters that differed between MIS-C and controls, indicating an interplay between apolipoproteins, immune response proteins, coagulation factors, platelet function, and the complement cascade. These intricate protein patterns indicated MIS-C as an immunometabolic condition with global hypercoagulability. Our findings emphasize the potential of AI-assisted proteomics as a powerful and unbiased tool for assessing disease pathogenesis and suggesting avenues for future interventions and impact on pediatric disease trajectories through early diagnosis.


Subject(s)
COVID-19 , Proteomics , Systemic Inflammatory Response Syndrome , Humans , Systemic Inflammatory Response Syndrome/diagnosis , Systemic Inflammatory Response Syndrome/blood , COVID-19/diagnosis , COVID-19/metabolism , COVID-19/complications , Child , Proteomics/methods , Female , Male , Child, Preschool , SARS-CoV-2 , Adolescent , Biomarkers/blood , Artificial Intelligence , Infant
13.
Diabetologia ; 67(8): 1602-1615, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38705923

ABSTRACT

AIMS/HYPOTHESES: Glucagon and glucagon-like peptide-1 (GLP-1) are derived from the same precursor; proglucagon, and dual agonists of their receptors are currently being explored for the treatment of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). Elevated levels of endogenous glucagon (hyperglucagonaemia) have been linked with hyperglycaemia in individuals with type 2 diabetes but are also observed in individuals with obesity and MASLD. GLP-1 levels have been reported to be largely unaffected or even reduced in similar conditions. We investigated potential determinants of plasma proglucagon and associations of glucagon receptor signalling with metabolic diseases based on data from the UK Biobank. METHODS: We used exome sequencing data from the UK Biobank for ~410,000 white participants to identify glucagon receptor variants and grouped them based on their known or predicted signalling. Data on plasma levels of proglucagon estimated using Olink technology were available for a subset of the cohort (~40,000). We determined associations of glucagon receptor variants and proglucagon with BMI, type 2 diabetes and liver fat (quantified by liver MRI) and performed survival analyses to investigate if elevated proglucagon predicts type 2 diabetes development. RESULTS: Obesity, MASLD and type 2 diabetes were associated with elevated plasma levels of proglucagon independently of each other. Baseline proglucagon levels were associated with the risk of type 2 diabetes development over a 14 year follow-up period (HR 1.13; 95% CI 1.09, 1.17; n=1562; p=1.3×10-12). This association was of the same magnitude across strata of BMI. Carriers of glucagon receptor variants with reduced cAMP signalling had elevated levels of proglucagon (ß 0.847; 95% CI 0.04, 1.66; n=17; p=0.04), and carriers of variants with a predicted frameshift mutation had higher levels of liver fat compared with the wild-type reference group (ß 0.504; 95% CI 0.03, 0.98; n=11; p=0.04). CONCLUSIONS/INTERPRETATION: Our findings support the suggestion that glucagon receptor signalling is involved in MASLD, that plasma levels of proglucagon are linked to the risk of type 2 diabetes development, and that proglucagon levels are influenced by genetic variation in the glucagon receptor, obesity, type 2 diabetes and MASLD. Determining the molecular signalling pathways downstream of glucagon receptor activation may guide the development of biased GLP-1/glucagon co-agonist with improved metabolic benefits. DATA AVAILABILITY: All coding is available through https://github.com/nicwin98/UK-Biobank-GCG.


Subject(s)
Biological Specimen Banks , Diabetes Mellitus, Type 2 , Obesity , Proglucagon , Receptors, Glucagon , Signal Transduction , Humans , Receptors, Glucagon/genetics , Receptors, Glucagon/metabolism , United Kingdom , Female , Proglucagon/metabolism , Proglucagon/genetics , Male , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Middle Aged , Obesity/blood , Aged , Adult , Body Mass Index , Glucagon/blood , Glucagon-Like Peptide 1/blood , UK Biobank
14.
Mol Oncol ; 18(10): 2393-2406, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38750007

ABSTRACT

Cancer of unknown primary (CUP) tumors are biologically very heterogeneous, which complicates stratification of patients for treatment. Consequently, these patients face limited treatment options and a poor prognosis. With this study, we aim to expand on the current knowledge of CUP biology by analyzing two cohorts: a well-characterized cohort of 44 CUP patients, and 213 metastatic patients with known primary. These cohorts were treated at the same institution and characterized by identical molecular assessments. Through comparative analysis of genomic and transcriptomic data, we found that CUP tumors were characterized by high expression of immune-related genes and pathways compared to other metastatic tumors. Moreover, CUP tumors uniformly demonstrated high levels of tumor-infiltrating leukocytes and circulating T cells, indicating a strong immune response. Finally, the genetic landscape of CUP tumors resembled that of other metastatic cancers and demonstrated mutations in established cancer genes. In conclusion, CUP tumors possess a distinct immunophenotype that distinguishes them from other metastatic cancers. These results may suggest an immune response in CUP that facilitates metastatic tumor growth while limiting growth of the primary tumor.


Subject(s)
Neoplasm Metastasis , Neoplasms, Unknown Primary , Humans , Neoplasms, Unknown Primary/genetics , Neoplasms, Unknown Primary/pathology , Male , Female , Middle Aged , Aged , Gene Expression Regulation, Neoplastic , Mutation , Transcriptome , Adult , Aged, 80 and over , Gene Expression Profiling , Cohort Studies , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphocytes, Tumor-Infiltrating/pathology
15.
Peptides ; 179: 171242, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38782050

ABSTRACT

Oxytocin has been proposed to possess glucose-stabilizing effects through the release of insulin and glucagon from the pancreas. Also, exogenous oxytocin has been shown to stimulate extrapancreatic glucagon secretion in depancreatized dogs. Here, we investigated the effect of exogenous oxytocin on circulating levels of pancreatic and gut-derived glucose-stabilizing hormones (insulin [measured as C-peptide], glucagon, glucagon-like peptide 1 [GLP-1], and glucose-dependent insulinotropic polypeptide). We studied nine pancreatectomized (PX) patients and nine healthy controls (CTRLs) (matched on age and body mass index) before, during, and after an intravenous infusion of 10 IU of oxytocin administered over 12 min. Oxytocin did not increase plasma glucagon levels, nor induce any changes in plasma glucose, C-peptide, or GIP in any of the groups. Oxytocin decreased plasma glucagon levels by 19 ± 10 % in CTRLs (from 2.0 ± 0.5 [mean ± SEM] to 1.3 ± 0.2 pmol/l, P = 0.0025) and increased GLP-1 by 42 ± 22 % in PX patients (from 9.0 ± 1.0-12.7 ± 1.0 pmol/l, P = 0.0003). Fasting plasma glucose levels were higher in PX patients compared with CTRLs (13.1 ± 1.1 vs. 5.1 ± 0.1 mmol/l, P < 0.0001). In conclusion, the present findings do not support pancreas-mediated glucose-stabilizing effects of acute oxytocin administration in humans and warrant further investigation of oxytocin's gluco-metabolic effects.


Subject(s)
Blood Glucose , Gastric Inhibitory Polypeptide , Glucagon-Like Peptide 1 , Glucagon , Insulin , Oxytocin , Pancreatectomy , Humans , Oxytocin/pharmacology , Oxytocin/administration & dosage , Oxytocin/blood , Oxytocin/metabolism , Male , Glucagon/blood , Glucagon/metabolism , Female , Middle Aged , Blood Glucose/metabolism , Glucagon-Like Peptide 1/blood , Glucagon-Like Peptide 1/metabolism , Insulin/blood , Insulin/metabolism , Gastric Inhibitory Polypeptide/blood , Gastric Inhibitory Polypeptide/metabolism , Aged , Adult , C-Peptide/blood , C-Peptide/metabolism
16.
Lancet Healthy Longev ; 5(5): e314-e325, 2024 May.
Article in English | MEDLINE | ID: mdl-38588687

ABSTRACT

BACKGROUND: Time-restricted eating (TRE) has been suggested to be a simple, feasible, and effective dietary strategy for individuals with overweight or obesity. We aimed to investigate the effects of 3 months of 10-h per-day TRE and 3 months of follow-up on bodyweight and cardiometabolic risk factors in individuals at high risk of type 2 diabetes. METHODS: This was a single-centre, parallel, superiority, open-label randomised controlled clinical trial conducted at Steno Diabetes Center Copenhagen (Denmark). The inclusion criteria were age 30-70 years with either overweight (ie, BMI ≥25 kg/m2) and concomitant prediabetes (ie, glycated haemoglobin [HbA1c] 39-47 mmol/mol) or obesity (ie, BMI ≥30 kg/m2) with or without prediabetes and a habitual self-reported eating window (eating and drinking [except for water]) of 12 h per day or more every day and of 14 h per day or more at least 1 day per week. Individuals were randomly assigned 1:1 to 3 months of habitual living (hereafter referred to as the control group) or TRE, which was a self-selected 10-h per-day eating window placed between 0600 h and 2000 h. Randomisation was done in blocks varying in size and was open for participants and research staff, but outcome assessors were masked during statistical analyses. The randomisation list was generated by an external statistician. The primary outcome was change in bodyweight, assessed after 3 months (12 weeks) of the intervention and after 3 months (13 weeks) of follow-up. Adverse events were reported and registered at study visits or if participants contacted study staff to report events between visits. This trial is registered on ClinicalTrials.gov (NCT03854656). FINDINGS: Between March 12, 2019, and March 2, 2022, 100 participants (66 [66%] were female and 34 [34%] were male; median age 59 years [IQR 52-65]) were enrolled and randomly assigned (50 to each group). Of those 100, 46 (92%) in the TRE group and 46 (92%) in the control group completed the intervention period. After 3 months of the intervention, there was no difference in bodyweight between the TRE group and the control group (-0·8 kg, 95% CI -1·7 to 0·2; p=0·099). Being in the TRE group was not associated with a lower bodyweight compared with the control group after subsequent 3-month follow-up (-0·2 kg, -1·6 to 1·2). In the per-protocol analysis, participants who completed the intervention in the TRE group lost 1·0 kg (-1·9 to -0·0; p=0·040) bodyweight compared with the control group after 3 months of intervention, which was not maintained after the 3-month follow-up period (-0·4 kg, -1·8 to 1·0). During the trial and follow-up period, one participant in the TRE group reported a severe adverse event: development of a subcutaneous nodule and pain when the arm was in use. This side-effect was evaluated to be related to the trial procedures. INTERPRETATION: 3 months of 10-h per-day TRE did not lead to clinically relevant effects on bodyweight in middle-aged to older individuals at high risk of type 2 diabetes. FUNDING: Novo Nordisk Foundation, Aalborg University, Helsefonden, and Innovation Fund Denmark.


Subject(s)
Body Weight , Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/epidemiology , Middle Aged , Female , Male , Denmark/epidemiology , Aged , Follow-Up Studies , Adult , Overweight , Obesity/epidemiology
17.
Peptides ; 176: 171213, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38604379

ABSTRACT

Glucagon is best known for its contribution to glucose regulation through activation of the glucagon receptor (GCGR), primarily located in the liver. However, glucagon's impact on other organs may also contribute to its potent effects in health and disease. Given that glucagon-based medicine is entering the arena of anti-obesity drugs, elucidating extrahepatic actions of glucagon are of increased importance. It has been reported that glucagon may stimulate secretion of arginine-vasopressin (AVP)/copeptin, growth hormone (GH) and adrenocorticotrophic hormone (ACTH) from the pituitary gland. Nevertheless, the mechanisms and whether GCGR is present in human pituitary are unknown. In this study we found that intravenous administration of 0.2 mg glucagon to 14 healthy subjects was not associated with increases in plasma concentrations of copeptin, GH, ACTH or cortisol over a 120-min period. GCGR immunoreactivity was present in the anterior pituitary but not in cells containing GH or ACTH. Collectively, glucagon may not directly stimulate secretion of GH, ACTH or AVP/copeptin in humans but may instead be involved in yet unidentified pituitary functions.


Subject(s)
Adrenocorticotropic Hormone , Glucagon , Glycopeptides , Humans , Glycopeptides/metabolism , Glucagon/metabolism , Glucagon/blood , Adrenocorticotropic Hormone/blood , Adrenocorticotropic Hormone/metabolism , Male , Adult , Female , Pituitary Gland/metabolism , Pituitary Gland/drug effects , Hydrocortisone/blood , Receptors, Glucagon/metabolism , Human Growth Hormone/metabolism , Growth Hormone/metabolism , Growth Hormone/blood , Middle Aged
18.
Metabolism ; 156: 155915, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38631460

ABSTRACT

INTRODUCTION: Glucagon receptor agonism is currently explored for the treatment of obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). The metabolic effects of glucagon receptor agonism may in part be mediated by increases in circulating levels of Fibroblast Growth Factor 21 (FGF21) and Growth Differentiation Factor 15 (GDF15). The effect of glucagon agonism on FGF21 and GDF15 levels remains uncertain, especially in the context of elevated insulin levels commonly observed in metabolic diseases. METHODS: We investigated the effect of a single bolus of glucagon and a continuous infusion of glucagon on plasma concentrations of FGF21 and GDF15 in conditions of endogenous low or high insulin levels. The studies included individuals with overweight with and without MASLD, healthy controls (CON) and individuals with type 1 diabetes (T1D). The direct effect of glucagon on FGF21 and GDF15 was evaluated using our in-house developed isolated perfused mouse liver model. RESULTS: FGF21 and GDF15 correlated with plasma levels of insulin, but not glucagon, and their secretion was highly increased in MASLD compared with CON and T1D. Furthermore, FGF21 levels in individuals with overweight with or without MASLD did not increase after glucagon stimulation when insulin levels were kept constant. FGF21 and GDF15 levels were unaffected by direct stimulation with glucagon in the isolated perfused mouse liver. CONCLUSION: The glucagon-induced secretion of FGF21 and GDF15 is augmented in MASLD and may depend on insulin. Thus, glucagon receptor agonism may augment its metabolic benefits in patients with MASLD through enhanced secretion of FGF21 and GDF15.


Subject(s)
Fibroblast Growth Factors , Glucagon , Growth Differentiation Factor 15 , Growth Differentiation Factor 15/metabolism , Growth Differentiation Factor 15/blood , Fibroblast Growth Factors/metabolism , Fibroblast Growth Factors/blood , Glucagon/blood , Glucagon/metabolism , Animals , Humans , Mice , Male , Female , Adult , Insulin/pharmacology , Insulin/blood , Insulin/metabolism , Middle Aged , Liver/metabolism , Liver/drug effects , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/blood , Obesity/metabolism , Mice, Inbred C57BL , Fatty Liver/metabolism , Overweight/metabolism
19.
Am J Physiol Gastrointest Liver Physiol ; 326(6): G736-G746, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38625142

ABSTRACT

Autoimmune liver diseases are associated with an increased risk of diabetes, yet the underlying mechanisms remain unknown. In this cross-sectional study, we investigated the glucose-regulatory disturbances in patients with autoimmune hepatitis (AIH, n = 19), primary biliary cholangitis (PBC, n = 15), and primary sclerosing cholangitis (PSC, n = 6). Healthy individuals (n = 24) and patients with metabolic dysfunction-associated steatotic liver disease (MASLD, n = 18) were included as controls. Blood samples were collected during a 120-min oral glucose tolerance test. We measured the concentrations of glucose, C-peptide, insulin, glucagon, and the two incretin hormones, glucose insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). We calculated the homeostasis model assessment of insulin resistance (HOMA-IR), whole body insulin resistance (Matsuda index), insulin clearance, and insulinogenic index. All patient groups had increased fasting plasma glucose and impaired glucose responses compared with healthy controls. Beta-cell secretion was increased in AIH, PBC, and MASLD but not in PSC. Patients with AIH and MASLD had hyperglucagonemia and hepatic, as well as peripheral, insulin resistance and decreased insulin clearance, resulting in hyperinsulinemia. Patients with autoimmune liver disease had an increased GIP response, and those with AIH or PBC had an increased GLP-1 response. Our data demonstrate that the mechanism underlying glucose disturbances in patients with autoimmune liver disease differs from that underlying MASLD, including compensatory incretin responses in patients with autoimmune liver disease. Our results suggest that glucose disturbances are present at an early stage of the disease.NEW & NOTEWORTHY Patients with autoimmune liver disease but without overt diabetes display glucose disturbances early on in their disease course. We identified pathophysiological traits specific to these patients including altered incretin responses.


Subject(s)
Blood Glucose , Hepatitis, Autoimmune , Insulin Resistance , Insulin , Humans , Female , Male , Middle Aged , Blood Glucose/metabolism , Cross-Sectional Studies , Adult , Insulin/blood , Hepatitis, Autoimmune/blood , Hepatitis, Autoimmune/metabolism , Hepatitis, Autoimmune/complications , Glucagon-Like Peptide 1/blood , Glucagon-Like Peptide 1/metabolism , Fatty Liver/metabolism , Fatty Liver/blood , Gastric Inhibitory Polypeptide/blood , Gastric Inhibitory Polypeptide/metabolism , Aged , Glucose Tolerance Test , Cholangitis, Sclerosing/blood , Cholangitis, Sclerosing/metabolism , Cholangitis, Sclerosing/complications , Glucagon/blood , Glucagon/metabolism , Liver Cirrhosis, Biliary/blood , Liver Cirrhosis, Biliary/metabolism , Liver Cirrhosis, Biliary/complications , C-Peptide/blood
20.
Nat Mach Intell ; 6(3): 354-367, 2024.
Article in English | MEDLINE | ID: mdl-38523679

ABSTRACT

Foundation models in deep learning are characterized by a single large-scale model trained on vast amounts of data serving as the foundation for various downstream tasks. Foundation models are generally trained using self-supervised learning and excel in reducing the demand for training samples in downstream applications. This is especially important in medicine, where large labelled datasets are often scarce. Here, we developed a foundation model for cancer imaging biomarker discovery by training a convolutional encoder through self-supervised learning using a comprehensive dataset of 11,467 radiographic lesions. The foundation model was evaluated in distinct and clinically relevant applications of cancer imaging-based biomarkers. We found that it facilitated better and more efficient learning of imaging biomarkers and yielded task-specific models that significantly outperformed conventional supervised and other state-of-the-art pretrained implementations on downstream tasks, especially when training dataset sizes were very limited. Furthermore, the foundation model was more stable to input variations and showed strong associations with underlying biology. Our results demonstrate the tremendous potential of foundation models in discovering new imaging biomarkers that may extend to other clinical use cases and can accelerate the widespread translation of imaging biomarkers into clinical settings.

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