Non-invasive glucose monitoring by NAD(P)H autofluorescence spectroscopy in fibroblasts and adipocytes: a model for skin glucose sensing.
The aim of this study was to develop an in vitro cell-culture model of skin-component cells to test the hypothesis that glucose can be monitored non-invasively by measuring NAD(P)H-related fluorescence changes in tissues. 3T3-L1 fibroblasts and adipocytes were grown in culture, and the response to added glucose was assessed by changes in steady-state autofluorescence at 400-500 nm [excitation at 340 nm, an index of NAD(P)H]. We also studied glucose-related fluorescence changes in cells stained with the mitochondrial marker, rhodamine-123. Fibroblasts and adipocytes showed glucose-dependent increases in autofluorescence with both short- and long-term exposure. Spectral properties indicated that the fluorescence was due to NAD(P)H production. With 5-h exposure to glucose, the maximal response was at 10-15 mmol/L glucose. Cells stained with the fluorescent mitochondrial marker, rhodamine-123, showed an immediate and marked decrease in fluorescence when exposed to glucose. We conclude that glucose can be sensed non-invasively by cellular fluorescence changes in fibroblasts and adipocytes. This is a model for the further exploration of fluorescence-based non-invasive metabolic monitoring in human diabetes.
Evans
Nicholas D
ND
Metabolic Unit, Guy's, King's and St Thomas's School of Medicine, Guy's Hospital, London, United Kingdom.
Gnudi
Luigi
L
Rolinski
Olaf J
OJ
Birch
David J S
DJ
Pickup
John C
JC
D020155:3-Hydroxybutyric Acid / Q000378:metabolism; D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000201:enzymology*; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002460:Cell Line; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology*; D005947:Glucose / Q000032:analysis*; D005973:Glutamine / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D009249:NADP / Q000032:analysis / Q000378:metabolism*; D019308:Palmitic Acid / Q000378:metabolism; D020112:Rhodamine 123 / Q000378:metabolism; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
D005973:Glutamine; D020112:Rhodamine 123; D019308:Palmitic Acid; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D009249:NADP; D005947:Glucose; D020155:3-Hydroxybutyric Acid