Construction of biosensor systems for determining the pathophysiological potential of carrageenan variants.
In vitro systems for monitoring safety of nutritional additives are desirable for high-throughput screenings and as a substitute for animal models. Carrageenan (CGN) is a sulfated polysaccharide widely used as a thickener and texturizer in human nutrition and is intensely discussed regarding its pathophysiological potential. Low molecular weight (lm) variants of CGN are considered to exert more profound pathophysiological effects in vivo than high molecular weight (hm) variants. We used a systematic approach to construct reporter systems allowing distinction between CGN-variants with different pathophysiological potential. Reporter systems utilizing segments of the CGN-responsive DMBT1 promoter did not display substantial activity in SW620 cells of intestinal epithelial origin. Genome-wide profiling revealed stronger qualitative and quantitative changes in global gene activities for hm-CGN than for lm-CGN (824 versus 91 genes; -6.64 to 22.33-fold for hm-CGN versus the range of -2.65 to 2.96-fold for lm-CGN). Reporter systems with segments of the IL-8 promoter showed a specific activation in response to hm-sulfated polysaccharides with lower pathophysiological potential in vivo and provided a better classification of CGN-variants than cytotoxicity assays in vitro. IL-8 reporter systems can be used for discerning between the effects of sulfated polysaccharides in vivo. Our data further provide initial insights into the molecular mechanisms that may play a role in the different effects of CGN-variants.
Riedel
Angela
A
Molecular Oncology, Medical Biotechnology Center, Institute of Medical Biology, University of Southern Denmark, Winsløwsparken 25, 5000 Odense C, Denmark.
End
Caroline
C
Christiansen
Helle
H
Renner
Marcus
M
Bender
Christian
C
Schmidt
Steffen
S
Korn
Bernhard
B
Sueltmann
Holger
H
Mollenhauer
Jan
J
D015374:Biosensing Techniques / Q000379:methods*; D002135:Calcium-Binding Proteins; D002351:Carrageenan / Q000737:chemistry / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000502:physiology; D004268:DNA-Binding Proteins; D015870:Gene Expression; D017930:Genes, Reporter; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology; D008970:Molecular Weight; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011956:Receptors, Cell Surface / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D049490:Systems Biology / Q000379:methods*; D025521:Tumor Suppressor Proteins
D002135:Calcium-Binding Proteins; C108174:DMBT1 protein, human; D004268:DNA-Binding Proteins; D016209:Interleukin-8; D016328:NF-kappa B; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; D002351:Carrageenan