Search results for "Retinol binding"
showing 10 items of 15 documents
Plasma Proteins, Yolk Proteins and Metal-Binding Proteins
1994
The extracellular fluid of the metazoans is not only a transport vehicle but also, for the majority of the body’s cells, their growth environment. Proteins play an important role here, providing colloid-osmotic pressure and acting as buffers. The most important parameter in this respect is their concentration which, depending upon the species, the developmental stage and the physiological conditions, can vary from less than 1 to more than 200 mg/ml (Table 5.1). In addition to these general functions, individual plasma proteins have various specific roles, e.g. in the transport of substances, in defence reactions, in blood clotting or in the solution of clots. At least in the case of the mor…
Xanthine oxidase catalyzes the oxidation of retinol.
2007
In mammals, xanthine oxidase (E.C. 1.17.3.2) catalyzes the hydroxylation of a wide variety of heterocyclic substrates such as purines, pyrimidines, and pterins, in addition to aldehydes [1] as all-trans-retinaldehyde [2-5]. Here, we show that buttermilk xanthine oxidase was capable to oxidizing all-trans-retinol (t-ROL) to all-trans-retinaldehyde (t-RAL) that was successively oxidized to all-trans-retinoic acid (t-RA). A rise in the enzyme activity, when t-ROL-CRBP complex was assayed, with respect to the free t-ROL, was observed. Furthermore, treatment of the enzyme with Na2S and glutathione resulted in a significant increment in catalytic activity toward t-ROL and t-RAL, due to the recons…
Moderate weight loss attenuates chronic endoplasmic reticulum stress and mitochondrial dysfunction in human obesity
2018
Abstract Objective In obese patients undergoing caloric restriction, there are several potential mechanisms involved in the improvement of metabolic outcomes. The present study further explores whether caloric restriction can modulate endoplasmic reticulum (ER) stress and mitochondrial function, as both are known to be mechanisms underlying inflammation and insulin resistance (IR) during obesity. Methods A total of 64 obese patients with BMI ≥35 kg/m2 underwent a dietary program consisting of 6 weeks of a very-low-calorie diet followed by 18 weeks of low-calorie diet. We evaluated changes in the metabolic and inflammatory markers -TNFα, hsCRP, complement component 3 (C3c), and retinol bindi…
High liver RBP4 protein content is associated with histological features in patients with genotype 1 chronic hepatitis C and with nonalcoholic steato…
2011
Abstract Background and aim To investigate the hepatic expression of retinol-binding protein-4 (RBP4) in chronic hepatitis C (CHC) and nonalcoholic steatohepatitis (NASH) patients, and its association with biochemical and histological patterns of liver damage. Materials and methods Sixty-six genotype 1 CHC and 32 NASH patients were tested for hepatic RBP4 expression. Liver expression at immunostaining was scored as 0 (slight), 1 (mild), 2 (moderate), and 3 (intense). In addition, the mRNA and the quantitative protein expressions of RBP4 were tested by PCR and by western blot, respectively, in 12 NASH and 28 CHC patients. Twelve subjects undergoing elective cholecystectomy served as controls…
Retinol encapsulated into amorphous Ca2+ polyphosphate nanospheres acts synergistically in MC3T3-E1 cells
2015
Both the quality and quantity of collagen, the major structural component of the skin, decrease in aging skin. We succeeded to encapsulate retinol into amorphous inorganic polyphosphate (polyP) nanoparticles together with calcium ions ("aCa-polyP-NP"), under formation of amorphous Ca-polyP/retinol nanospheres ("retinol/aCa-polyP-NS"). The globular nanospheres are not cytotoxic, show an almost uniform size of ≈ 45 nm and have a retinol content of around 25%. Both components of those nanospheres, retinol and the aCa-polyP-NP, if administered together, caused a strong increase in proliferation of mouse calvaria MC3T3 cells. The expressions of collagen types I, II and III genes, but not the exp…
PS-078 Clinical Relevance Of Gamma-glutamyl Transpeptidase In Childhood Obesity
2014
Background and aims Metabolic risk leads to severe comorbidities in obesity. We evaluate the relationship between the values of gamma-glutamyl trans peptidase (GGT), a marker of hepatic involvement, and cardio metabolic risk factors in obese children. Methods A prospective cross-sectional study of 147 children (aged 7 to 16 years) was carried out. Ninety-five children were obese with a body mass index standard deviation score (SDS-BMI) >2 and 52 children were normal weight. Patients with endocrine disease or syndromic obesity were excluded. We have analysed clinical parameters of adiposity (fat mass by bioelectrical impedance, waist and hip circumference), blood pressure, and classical bioc…
Retinol-binding protein 4: a new marker of virus-induced steatosis in patients infected with hepatitis C virus genotype 1.
2008
Retinol-binding protein 4 (RBP4) is an adipocytokine associated with insulin resistance (IR). We tested serum levels of RBP4 to assess its link with steatosis in patients with genotype 1 chronic hepatitis C (CHC) or nonalcoholic fatty liver disease (NAFLD). Nondiabetic patients with CHC (n = 143) or NAFLD (n = 37) were evaluated by liver biopsy and anthropometric and metabolic measurements, including IR by the homeostasis model assessment. Biopsies were scored by Scheuer classification for CHC, and Kleiner for NAFLD. Steatosis was tested as a continuous variable and graded as absent-mild <30%, or moderate-severe > or =30%. Thirty nondiabetic, nonobese blood donors served as controls. …
Association of Serum Retinol Binding Protein 4 with Atherogenic Dyslipidemia in Morbid Obese Patients
2013
Retinol binding protein 4 (RBP4) is an adipokine that may contribute to the development of insulin resistance. However, how this adipokine is affected and its possible involvement in lipid metabolism in obese patients with varying degrees of insulin resistance is yet to be determined. A total of 299 middle-aged morbid obese patients (BMI>40 kg/m(2)) were divided in euglycemic, metabolic syndrome or type 2 diabetic. Anthropometric measurements, biochemical variables and systemic RBP4 levels were determined. RBP4 levels were significantly higher in patients with metabolic syndrome and type 2 diabetes than in euglycemic subjects (42.9±14.6; 42.3±17.0 and 37.4±11.7 µg/ml, respectively) and corr…
Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease
2018
SUMMARY Maternally skewed transmission of traits has been associated with genomic imprinting and oocyte-derived mRNA. We report canine congenital eye malformations, caused by an amino acid deletion (K12del) near the N terminus of retinol-binding protein (RBP4). The disease is only expressed when both dam and offspring are deletion homozygotes. RBP carries vitamin A (retinol) from hepatic stores to peripheral tissues, including the placenta and developing eye, where it is required to synthesize retinoic acid. Gestational vitamin A deficiency is a known risk factor for ocular birth defects. The K12del mutation disrupts RBP folding in vivo, decreasing its secretion from hepatocytes to serum. T…
Vitamin A (Retinol) und Retinolbindendes-Protein (RBP) im Serum bei Maldigestion, Malabsorption und Lebercirrhose
1974
Bei Normalpersonen und Patienten mit Malabsorption, Maldigestion und Lebercirrhose wurden vor und nach oraler Belastung mit 600 000 E Vitamin-A-palmitat bzw. wasserloslichem Vitamin A im Serum der Spiegel des Vitamin A (Retinol), des Retinol-bindenden Proteins (RBP) und Praealbumin bestimmt. In der Kontrolle steigt das Retinol nach Belastung signifikant an und erreicht nach 5 Std sein Maximum. Das RBP liegt im Mittel bei 42,25 mg/L, der Praealbuminspiegel bei 400 mg/L. Patienten mit Malabsorption und Lebercirrhose zeigen vor und nach Belastung mit Vitamin-A-palmitat einen gegenuber der Kontrolle verminderten Retinolspiegel. In der Gruppe der Maldigestion ist der Nuchternspiegel des Retinols…