Comparison of different methods to investigate postprandial lipaemia

Postprandial hyperlipidaemia has been associated with coronary artery disease (CAD). We investigated which of the generally used methods to test postprandial lipaemia differentiated best between patients with premature CAD (50 +/- 4 years, n=20) and healthy controls. Furthermore, the effects of rosuvastatin 40 mg/day on postprandial parameters were assessed. Standardised oral fat-loading tests (OFLT) and ambulant self-measurements of daylong capillary triglycerides (TGc) were performed. Total responses of individual lipoproteins, plasma TG (TGp) and remnant-like particle cholesterol (RLP-C) were estimated as area under the curve (AUC). Most AUCs were highest in untreated patients and reached control levels after rosuvastatin. From all AUCs, RLP-C-AUC was best associated to TGp-AUC in untreated patients and controls (adjusted R(2)=0.84, beta=0.92, P <0.001). From all parameters of postprandial lipaemia, TGc-AUC differentiated best between untreated patients and controls (adjusted R(2)=0.48, beta=0.70, p <0.0001) and between patients on and off-treatment (adjusted R(2)=0.34, beta=0.60, p <0.0001). Our findings indicate that the real-life TG load, instead of metabolic ward testing, is the best parameter of postprandial lipaemia to identify patients with premature coronary sclerosis and to evaluate postprandial effects of statin treatmen

Diet-dependent function of the extracellular matrix proteoglycan Lumican in obesity and glucose homeostasis.

Objective: Extracellular matrix remodeling is required for adipose expansion under increased caloric intake. In turn, inhibited expandability due to aberrant collagen deposition promotes insulin resistance and progression towards the metabolic syndrome. An emerging role for the small leucine-rich proteoglycan Lumican in metabolically driven nonalcoholic fatty liver disease sparks an interest in further understanding its role in diet-induced obesity and metabolic complications.Methods: Whole body ablation of Lumican (Lum(-/-)) gene and adeno-associated virus-mediated over-expression were used in combination with control or high fat diet to assess energy balance, glucose homeostasis as well as adipose tissue health and remodeling.Results: Lumican was found to be particularly enriched in the stromal cells isolated from murine gonadal white adipose tissue. Likewise murine and human visceral fat showed a robust increase in Lumican as compared to fat from the subcutaneous depot. Lumican null female mice exhibited moderately increased fat mass, decreased insulin sensitivity and increased liver triglycerides in a diet-dependent manner. These changes coincided with inflammation in adipose tissue and no overt effects in adipose expandability, i.e. adipocyte formation and hypertrophy. Lumican over-expression in visceral fat and liver resulted in improved insulin sensitivity and glucose clearance.Conclusions: These data indicate that Lumican may represent a functional link between the extracellular matrix, glucose homeostasis, and features of the metabolic syndrome. (C) 2018 The Authors. Published by Elsevier GmbH

Control of diabetic hyperglycaemia and insulin resistance through TSC22D4.

Obesity-related insulin resistance represents the core component of the metabolic syndrome, promoting glucose intolerance, pancreatic beta cell failure and type 2 diabetes. Efficient and safe insulin sensitization and glucose control remain critical therapeutic aims to prevent diabetic late complications Here, we identify transforming growth factor beta-like stimulated clone (TSC) 22 D4 as a molecular determinant of insulin signalling and glucose handling. Hepatic TSC22D4 inhibition both prevents and reverses hyperglycaemia, glucose intolerance and insulin resistance in diabetes mouse models. TSC22D4 exerts its effects on systemic glucose homeostasis - at least in part - through the direct transcriptional regulation of the small secretory protein lipocalin 13 (LCN13). Human diabetic patients display elevated hepatic TSC22D4 expression, which correlates with decreased insulin sensitivity, hyperglycaemia and LCN13 serum levels. Our results establish TSC22D4 as a checkpoint in systemic glucose metabolism in both mice and humans, and propose TSC22D4 inhibition as an insulin sensitizing option in diabetes therapy

Cited4 is a sex‐biased mediator of the antidiabetic glitazone response in adipocyte progenitors

Abstract Most antidiabetic drugs treat disease symptoms rather than adipose tissue dysfunction as a key pathogenic cause in the metabolic syndrome and type 2 diabetes. Pharmacological targeting of adipose tissue through the nuclear receptor PPARg, as exemplified by glitazone treatments, mediates efficacious insulin sensitization. However, a better understanding of the context‐specific PPARg responses is required for the development of novel approaches with reduced side effects. Here, we identified the transcriptional cofactor Cited4 as a target and mediator of rosiglitazone in human and murine adipocyte progenitor cells, where it promoted specific sets of the rosiglitazone‐dependent transcriptional program. In mice, Cited4 was required for the proper induction of thermogenic expression by Rosi specifically in subcutaneous fat. This phenotype had high penetrance in females only and was not evident in beta‐adrenergically stimulated browning. Intriguingly, this specific defect was associated with reduced capacity for systemic thermogenesis and compromised insulin sensitization upon therapeutic rosiglitazone treatment in female but not male mice. Our findings on Cited4 function reveal novel unexpected aspects of the pharmacological targeting of PPARg

A hepatic GAbp-AMPK axis links inflammatory signaling to systemic vascular damage.

Increased pro-inflammatory signaling is a hallmark of&nbsp;metabolic dysfunction in obesity and diabetes. Although both inflammatory and energy substrate handling processes represent critical layers of metabolic control, their molecular integration sites remain largely unknown. Here, we identify the heterodimerization interface between the &alpha; and &beta; subunits of transcription factor GA-binding protein (GAbp) as a negative target of tumor necrosis factor alpha (TNF-&alpha;) signaling. TNF-&alpha; prevented GAbp&alpha; and &beta; complex formation via reactive oxygen species (ROS), leading to the non-energy-dependent transcriptional inactivation of AMP-activated kinase (AMPK) &beta;1, which was identified as a direct hepatic GAbp target. Impairment of AMPK&beta;1, in turn, elevated downstream cellular cholesterol biosynthesis, and hepatocyte-specific ablation of GAbp&alpha; induced systemic hypercholesterolemia and early macro-vascular lesion formation in mice. As GAbp&alpha; and AMPK&beta;1 levels were also found to correlate in obese human patients, the ROS-GAbp-AMPK pathway may represent a key component of a hepato-vascular axis in diabetic long-term complications

Platelet GPIb alpha is a mediator and potential interventional target for NASH and subsequent liver cancer

Non-alcoholic fatty liver disease ranges from steatosis to non-alcoholic steatohepatitis (NASH), potentially progressing to cirrhosis and hepatocellular carcinoma (HCC). Here, we show that platelet number, platelet activation and platelet aggregation are increased in NASH but not in steatosis or insulin resistance. Antiplatelet therapy (APT; aspirin/clopidogrel, ticagrelor) but not nonsteroidal anti-inflammatory drug (NSAID) treatment with sulindac prevented NASH and subsequent HCC development. Intravital microscopy showed that liver colonization by platelets depended primarily on Kupffer cells at early and late stages of NASH, involving hyaluronan-CD44 binding. APT reduced intrahepatic platelet accumulation and the frequency of platelet–immune cell interaction, thereby limiting hepatic immune cell trafficking. Consequently, intrahepatic cytokine and chemokine release, macrovesicular steatosis and liver damage were attenuated. Platelet cargo, platelet adhesion and platelet activation but not platelet aggregation were identified as pivotal for NASH and subsequent hepatocarcinogenesis. In particular, platelet-derived GPIbα proved critical for development of NASH and subsequent HCC, independent of its reported cognate ligands vWF, P-selectin or Mac-1, offering a potential target against NASH