TY  - JOUR
A1  - Martin-Creuzburg, Dominik
A1  - Oexle, Sarah
A1  - Wacker, Alexander
T1  - Thresholds for sterol-limited growth of Daphnia magna: A comparative approach using 10 different sterols
JF  - Journal of chemical ecology
N2  - Arthropods are incapable of synthesizing sterols de novo and thus require a dietary source to cover their physiological demands. The most prominent sterol in animal tissues is cholesterol, which is an indispensable structural component of cell membranes and serves as precursor for steroid hormones. Instead of cholesterol, plants and algae contain a variety of different phytosterols. Consequently, herbivorous arthropods have to metabolize dietary phytosterols to cholesterol to meet their requirements for growth and reproduction. Here, we investigated sterol-limited growth responses of the freshwater herbivore Daphnia magna by supplementing a sterol-free diet with increasing amounts of 10 different phytosterols and comparing thresholds for sterol-limited growth. In addition, we analyzed the sterol composition of D. magna to explore sterol metabolic constraints and bioconversion capacities. We show that dietary phytosterols strongly differ in their potential to support somatic growth of D. magna. The dietary threshold concentrations obtained by supplementing the different sterols cover a wide range (3.5-34.4 mu g mg C-1) and encompass the one for cholesterol (8.9 mu g mg C-1), indicating that certain phytosterols are more efficient in supporting somatic growth than cholesterol (e.g., fucosterol, brassicasterol) while others are less efficient (e.g., dihydrocholesterol, lathosterol). The dietary sterol concentration gradients revealed that the poor quality of particular sterols can be alleviated partially by increasing dietary concentrations, and that qualitative differences among sterols are most pronounced at low to moderate dietary concentrations. We infer that the dietary sterol composition has to be considered in zooplankton nutritional ecology to accurately assess potential sterol limitations under field conditions.
KW  - Cholesterol
KW  - Daphnia
KW  - Food quality
KW  - Nutrition
KW  - Phytosterols
KW  - Sterols
Y1  - 2014
U6  - https://doi.org/10.1007/s10886-014-0486-1
SN  - 0098-0331
SN  - 1573-1561
VL  - 40
IS  - 9
SP  - 1039
EP  - 1050
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Yang, Fang
A1  - Lai, Xinlong
A1  - Deng, Li
A1  - Liu, Xiaoxiao
A1  - Li, Jian
A1  - Zeng, Shuixiu
A1  - Zhang, Cheng
A1  - Hocher, Carl-Friedrich
A1  - Hocher, Berthold
T1  - Association of endothelin-1 gene polymorphisms with the clinical phenotype in primary nephrotic syndrome of children
JF  - Life sciences : molecular, cellular and functional basis of therapy
N2  - Aims:This study aims to investigate the relationship between plasma endothelin-1 (ET-1) concentrations, ET-1 gene polymorphisms in loci rs5370, rs1630736, 3A/4A and clinical features of primary nephrotic syndrome (NS) in children.
 Materials and methods: Thirty-six children with primary NS were selected as case group, and 94 healthy children were selected as control group. All subjects were genotyped for three single nucleotide polymorphisms (SNPs) (rs5370, rs10478694 [3A4A) and rs 1630736) in the ET-1 gene by gene sequencing. The plasma ET-1 concentrations were measured using a radio-immunoassay.
 Key findings: Plasma ET-1 concentrations were higher in NS patients (P = 0.007) as compared to healthy children. The allele frequencies between control and NS patients were significantly different only with respect to the rs10478694 SNP of the ET-1 gene. The allele frequencies between control and NS patients for the rs5370 SNP showed a trend towards difference (P = 0.057). Plasma cholesterol in NS patients is associated with both: the Cl genotype in locus rs5370 and the 3A4A genotype in locus rs10478694 (P < 0.05 in both cases).
 Significance: The ET systems might play a disease modifying role in pediatric NS. Plasma cholesterol, a hallmark of NS. seems to be associated with genetic variations within the human ET-1 gene. (C) 2014 Elsevier Inc. All rights reserved.
KW  - Endothelin-1
KW  - Gene polymorphism
KW  - Childhood nephrotic syndrome
KW  - Cholesterol
Y1  - 2014
U6  - https://doi.org/10.1016/j.lfs.2014.04.010
SN  - 0024-3205
SN  - 1879-0631
VL  - 118
IS  - 2
SP  - 446
EP  - 450
PB  - Elsevier
CY  - Oxford
ER  -