TY  - JOUR
A1  - Halilbasic, Emina
A1  - Fuerst, Elisabeth
A1  - Heiden, Denise
A1  - Japtok, Lukasz
A1  - Diesner, Susanne C.
A1  - Trauner, Michael
A1  - Kulu, Askin
A1  - Jaksch, Peter
A1  - Hoetzenecker, Konrad
A1  - Kleuser, Burkhard
A1  - Kazemi-Shirazi, Lili
A1  - Untersmayr, Eva
T1  - Plasma levels of the bioactive sphingolipid metabolite S1P in adult cystic fibrosis patients
BT  - potential target for immunonutrition?
JF  - Nutrients
N2  - Recent research has linked sphingolipid (SL) metabolism with cystic fibrosis transmembrane conductance regulator (CFTR) activity, affecting bioactive lipid mediator sphingosine-1-phosphate (S1P). We hypothesize that loss of CFTR function in cystic fibrosis (CF) patients influenced plasma S1P levels. Total and unbound plasma S1P levels were measured in 20 lung-transplanted adult CF patients and 20 healthy controls by mass spectrometry and enzyme-linked immunosorbent assay (ELISA). S1P levels were correlated with CFTR genotype, routine laboratory parameters, lung function and pathogen colonization, and clinical symptoms. Compared to controls, CF patients showed lower unbound plasma S1P, whereas total S1P levels did not differ. A positive correlation of total and unbound S1P levels was found in healthy controls, but not in CF patients. Higher unbound S1P levels were measured in Delta F508-homozygous compared to Delta F508-heterozygous CF patients (p = 0.038), accompanied by higher levels of HDL in Delta F508-heterozygous patients. Gastrointestinal symptoms were more common in Delta F508 heterozygotes compared to Delta F508 homozygotes. This is the first clinical study linking plasma S1P levels with CFTR function and clinical presentation in adult CF patients. Given the emerging role of immunonutrition in CF, our study might pave the way for using S1P as a novel biomarker and nutritional target in CF.
KW  - sphingolipids
KW  - sphingosine-1-phosphate
KW  - intestine
KW  - high density
KW  - lipoproteins
KW  - cystic fibrosis
KW  - Delta F508 mutation
KW  - immunonutrition
Y1  - 2020
U6  - https://doi.org/10.3390/nu12030765
SN  - 2072-6643
VL  - 12
IS  - 3
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Japtok, Lukasz
A1  - Schmitz, Elisabeth I.
A1  - Fayyaz, Susann
A1  - Krämer, Stephanie
A1  - Hsu, Leigh J.
A1  - Kleuser, Burkhard
T1  - Sphingosine 1-phosphate counteracts insulin signaling in pancreatic beta-cells via the sphingosine 1-phosphate receptor subtype 2
JF  - The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology
N2  - Glucolipotoxic stress has been identified as a key player in the progression of pancreatic beta-cell dysfunction contributing to insulin resistance and the development of type 2 diabetes mellitus (T2D). It has been suggested that bioactive lipid intermediates, formed under lipotoxic conditions, are involved in these processes. Here, we show that sphingosine 1-phosphate (S1P) levels are not only increased in palmitate-stimulated pancreatic beta-cells but also regulate beta-cell homeostasis in a divergent manner. Although S1P possesses a prosurvival effect in beta-cells, an enhanced level of the sphingolipid antagonizes insulin-mediated cell growth and survival via the sphingosine 1-phosphate receptor subtype 2 (S1P(2)) followed by an inhibition of Akt-signaling. In an attempt to investigate the role of the S1P/S1P(2) axis in vivo, the New Zealand obese (NZO) diabetic mouse model, characterized by beta-cell loss under high-fat diet (HFD) conditions, was used. The occurrence of T2D was accompanied by an increase of plasma S1P levels. To examine whether S1P contributes to the morphologic changes of islets via S1P(2), the receptor antagonist JTE-013 was administered. Most interestingly, JTE-013 rescued beta-cell damage clearly indicating an important role of the S1P(2) in beta-cell homeostasis. Therefore, the present study provides a new therapeutic strategy to diminish beta-cell dysfunction and the development of T2D.
KW  - type 2 diabetes mellitus
KW  - sphingolipids
KW  - survival
KW  - proliferation
KW  - Akt signaling
Y1  - 2015
U6  - https://doi.org/10.1096/fj.14-263194
SN  - 0892-6638
SN  - 1530-6860
VL  - 29
IS  - 8
SP  - 3357
EP  - 3369
PB  - Federation of American Societies for Experimental Biology
CY  - Bethesda
ER  -