Ultraviolet A induces transport of compatible organic osmolytes in human dermal fibroblasts.
Compatible organic osmolytes, such as betaine, myo-inositol and taurine, are involved in cell protection. Human dermal fibroblasts accumulate these osmolytes and express mRNA specific for their transporting systems betaine-/gamma-amino-n-butyric acid (GABA) transporter (BGT-1), sodium-dependent myo-inositol transporter (SMIT) and taurine transporter (TAUT). Taurine uptake was about sixfold higher than that of betaine and myo-inositol. Compared with normoosmotic (305 mOsm/l) control, hyperosmotic exposure (405 mOsm/l) led to a twofold induction of osmolyte uptake. Ultraviolet A (UVA) upregulated osmolyte transporter mRNA levels and increased osmolyte uptake. Taurine inhibited UVA-induced interleukin-6 (Il-6) mRNA expression by 40%. Furthermore, Il-6 accumulation in the supernatants of UVA-irradiated dermal fibroblasts was much slower when cells were preincubated with taurine. These data indicate that taurine accumulation seems to be part of the fibroblast response to UVA radiation and may protect against UVA-induced Il-6 overexpression.
Department of Gastroenterology, Hepatology and Infectiology, Düsseldorf, Germany. dr.ulrich.warskulat@freenet.de
Ulrich
U
Warskulat
Stefanie
S
Brookmann
Ingo
I
Felsner
Heidi
H
Brenden
Susanne
S
Grether-Beck
Dieter
D
Häussinger
D001622:Betaine / Q000493:pharmacokinetics / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000528:radiation effects; D002352:Carrier Proteins / Q000235:genetics; D002478:Cells, Cultured; D020405:Dermis / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D004573:Electrolytes / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D050485:GABA Plasma Membrane Transport Proteins; D015870:Gene Expression / Q000187:drug effects / Q000528:radiation effects; D006360:Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D007294:Inositol / Q000493:pharmacokinetics / Q000494:pharmacology; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics; D026901:Membrane Transport Proteins / Q000235:genetics; D009930:Organic Chemicals / Q000378:metabolism*; D009994:Osmolar Concentration; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D027981:Symporters / Q000235:genetics; D013654:Taurine / Q000493:pharmacokinetics / Q000494:pharmacology; D014466:Ultraviolet Rays; D000099247:Taurine Transporters
D001622:Betaine; D002352:Carrier Proteins; D004573:Electrolytes; D050485:GABA Plasma Membrane Transport Proteins; D006360:Heat-Shock Proteins; D007294:Inositol; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009930:Organic Chemicals; D012333:RNA, Messenger; D012462:Saline Solution, Hypertonic; D027981:Symporters; D013654:Taurine; D000099247:Taurine Transporters; C072207:betaine plasma membrane transport proteins; C073884:SLC5A3 protein, human