scholarly journals Toll-like receptors 1–9 are elevated in livers with fructose-induced hepatic steatosis

2011 ◽  
Vol 107 (12) ◽  
pp. 1727-1738 ◽  
Author(s):  
Sabine Wagnerberger ◽  
Astrid Spruss ◽  
Giridhar Kanuri ◽  
Valentina Volynets ◽  
Carolin Stahl ◽  
...  
Keyword(s):  
Tap Water ◽  
Human Subjects ◽  
Critical Role ◽  
Retinol Binding Protein ◽  
Toll Like Receptors ◽  
Water Control ◽  
Alcoholic Fatty Liver ◽  
Retinol Binding Protein 4 ◽  
Bacterial Endotoxins ◽  
Tnf Α

Studies in animals and human subjects indicate that gut-derived bacterial endotoxins may play a critical role in the development of non-alcoholic fatty liver disease (NAFLD). In the present study, we investigated if the liver is also sensitised by other microbial components during the onset of fructose-induced steatosis in a mouse model. C57BL/6 mice were either fed with 30 % fructose solution or tap water (control) with or without antibiotics for 8 weeks. Expression of toll-like receptors (TLR)1–9, TNF-α, inducible NO synthase (iNOS), myeloid differentiation factor 88 (MyD88) and number of F4/80 positive cells in the liver were assessed. Occludin protein, DNA of microbiota in the small and large intestine and retinol binding protein 4 (RBP4) in plasma were analysed using Western blot, DNA fingerprinting and ELISA, respectively. F4/80 positive cells were determined by immunohistochemistry. The accumulation of TAG found in the livers of fructose-fed mice was associated with a significant induction of TLR 1–4 and 6–8. Plasma RBP4 concentration and hepatic mRNA expression levels of TNF-α, iNOS, MyD88 and number of F4/80 positive cells of fructose-fed animals were significantly higher than those of controls; however, these effects of fructose were attenuated in antibiotic-treated mice. Whereas protein concentration of occludin was lower in the duodenum of fructose-treated mice, no systematic alterations of microbiota were found in this part of the intestine. Taken together, these data support the hypothesis that (1) an increased intestinal translocation of microbial components and (2) an increased number of F4/80 positive cells and induction of several TLR and dependent pathways (e.g. MyD88 and iNOS) may be involved in the onset of fructose-induced NAFLD.

Elevated level of circulatory sTLT1 induces inflammation through SYK/MEK/ERK signalling in coronary artery disease

2019 ◽  
Vol 133 (22) ◽  
pp. 2283-2299
Author(s):  
Apabrita Ayan Das ◽  
Devasmita Chakravarty ◽  
Debmalya Bhunia ◽  
Surajit Ghosh ◽  
Prakash C. Mandal ◽  
...  
Keyword(s):  
Risk Factors ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Chronic Inflammation ◽  
Ex Vivo ◽  
Human Subjects ◽  
Critical Role ◽  
Atherosclerotic Cardiovascular Disease ◽  
Tnf Α ◽  
Artery Disease

Abstract The role of inflammation in all phases of atherosclerotic process is well established and soluble TREM-like transcript 1 (sTLT1) is reported to be associated with chronic inflammation. Yet, no information is available about the involvement of sTLT1 in atherosclerotic cardiovascular disease. Present study was undertaken to determine the pathophysiological significance of sTLT1 in atherosclerosis by employing an observational study on human subjects (n=117) followed by experiments in human macrophages and atherosclerotic apolipoprotein E (apoE)−/− mice. Plasma level of sTLT1 was found to be significantly (P<0.05) higher in clinical (2342 ± 184 pg/ml) and subclinical cases (1773 ± 118 pg/ml) than healthy controls (461 ± 57 pg/ml). Moreover, statistical analyses further indicated that sTLT1 was not only associated with common risk factors for Coronary Artery Disease (CAD) in both clinical and subclinical groups but also strongly correlated with disease severity. Ex vivo studies on macrophages showed that sTLT1 interacts with Fcɣ receptor I (FcɣRI) to activate spleen tyrosine kinase (SYK)-mediated downstream MAP kinase signalling cascade to activate nuclear factor-κ B (NF-kB). Activation of NF-kB induces secretion of tumour necrosis factor-α (TNF-α) from macrophage cells that plays pivotal role in governing the persistence of chronic inflammation. Atherosclerotic apoE−/− mice also showed high levels of sTLT1 and TNF-α in nearly occluded aortic stage indicating the contribution of sTLT1 in inflammation. Our results clearly demonstrate that sTLT1 is clinically related to the risk factors of CAD. We also showed that binding of sTLT1 with macrophage membrane receptor, FcɣR1 initiates inflammatory signals in macrophages suggesting its critical role in thrombus development and atherosclerosis.

scholarly journals Ghrelin- and GH-induced insulin resistance: no association with retinol-binding protein-4

2013 ◽  
Vol 2 (2) ◽  
pp. 96-103 ◽  
Author(s):  
Esben Thyssen Vestergaard ◽  
Morten B Krag ◽  
Morten M Poulsen ◽  
Steen B Pedersen ◽  
Niels Moller ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Binding Protein ◽  
Human Subjects ◽  
Retinol Binding Protein ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Retinol Binding Protein 4 ◽  
Euglycemic Clamp ◽  
Hyperinsulinemic Euglycemic Clamp

ObjectiveSupraphysiological levels of ghrelin and GH induce insulin resistance. Serum levels of retinol-binding protein-4 (RBP4) correlate inversely with insulin sensitivity in patients with type 2 diabetes. We aimed to determine whether ghrelin and GH affect RBP4 levels in human subjects.Materials and methodsTo study GH-independent effects of ghrelin, seven hypopituitary men undergoing replacement therapy with GH and hydrocortisone were given ghrelin (5 pmol/kg per min) and saline infusions for 300 min in a randomized, double-blind, placebo-controlled, crossover design. Circulating RBP4 levels were measured at baseline and during a hyperinsulinemic–euglycemic clamp on both study days. To study the direct effects of GH, nine healthy men were treated with GH (2 mg at 2200 h) and placebo for 8 days in a randomized, double-blind, placebo-controlled, crossover study. Serum RBP4 levels were measured before and after treatment, and insulin sensitivity was measured by the hyperinsulinemic–euglycemic clamp technique.ResultsGhrelin acutely decreased peripheral insulin sensitivity. Serum RBP4 concentrations decreased in response to insulin infusion during the saline experiment (mg/l): 43.2±4.3 (baseline) vs 40.4±4.2 (clamp), P<0.001, but this effect was abrogated during ghrelin infusion (mg/l): 42.4±4.5 (baseline) vs 42.9±4.7 (clamp), P=0.73. In healthy subjects, serum RBP4 levels were not affected by GH administration (mg/l): 41.7±4.1 (GH) vs 43.8±4.6 (saline), P=0.09, although GH induced insulin resistance.Conclusionsi) Serum RBP4 concentrations decrease in response to hyperinsulinemia, ii) ghrelin abrogates the inhibitory effect of insulin on circulating RBP4 concentrations, and iii) ghrelin as well as GH acutely induces insulin resistance in skeletal muscle without significant changes in circulating RBP4 levels.

Circulating and liver tissue levels of retinol-binding protein-4 in non-alcoholic fatty liver disease

2009 ◽  
Vol 39 (10) ◽  
pp. 972-978 ◽  
Author(s):  
Maria Schina ◽  
John Koskinas ◽  
Dina Tiniakos ◽  
Emilia Hadziyannis ◽  
Savvas Savvas ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Liver Tissue ◽  
Fatty Liver Disease ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Alcoholic Fatty Liver ◽  
Retinol Binding Protein 4 ◽  
Tissue Levels ◽  
Alcoholic Fatty Liver Disease

scholarly journals Transcriptomic Analysis of Porcine Granulosa Cells Overexpressing Retinol Binding Protein 4

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 615
Author(s):  
Zhao ◽  
Li ◽  
Zhou
Keyword(s):  
Signaling Pathway ◽  
Granulosa Cells ◽  
High Throughput Sequencing ◽  
Fatty Acid Biosynthesis ◽  
Reaction Pathway ◽  
Binding Protein ◽  
Quantitative Polymerase Chain Reaction ◽  
Retinol Binding Protein ◽  
Alcoholic Fatty Liver ◽  
Retinol Binding Protein 4

Retinol binding protein 4 (RBP4), mainly secreted by the liver and adipocytes, is a transporter of vitamin A. RBP4 has been shown to be involved in several pathophysiological processes, such as obesity, insulin resistance, and cardiovascular risk. Reports have indicated the high expression levels of RBP4 in cystic follicles. However, the role of RBP4 in mammalian follicular granulosa cells (GCs) remains largely unknown. To illustrate the molecular pathways associated with the effects of RBP4 on GCs, we used high-throughput sequencing to detect differential gene expression in GCs overexpressing RBP4. A total of 113 differentially expressed genes (DEGs) were identified in RBP4-overexpressing GCs, and they included 71 upregulated and 42 downregulated genes. The differential expressions of the top 10 DEGs were further confirmed by real-time quantitative polymerase chain reaction. Pathway analysis indicated that the DEGs are mostly involved in oxidative phosphorylation, Parkinson’s disease, non-alcoholic fatty liver disease, Huntington’s disease, cardiac muscle contraction, Alzheimer’s disease, fatty acid biosynthesis, AMP-activated protein kinase signaling pathway, and insulin signaling pathway. Genes in these pathways should be useful for future studies on GCs. Altogether, the results of our study establish a framework for understanding the potential functions of RBP4 in porcine GCs.

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