Background: Autofluorescence in hepatology is a promising insitu, diagnostic tool to detect diseases in real time and support the selection of donor organs for transplantation. In this concern, we aimed to investigate lipids as new autofluorescence biomarkers of liver metabolic alterations, since the changes in their accumulation and composition and excessive fatty acid trafficking are manifestation of metabolic syndrome and risk of disorder progression. We therefore characterized the autofluorescence of two diet induced or genetic fatty liver models with established redox metabolism differences, focusing on fluorescing fatty acids. Study: Fatty livers were from Wistar rats, administered with methionine/choline deficient diet (MCD-WI), or Zucker (fa/fa) rats (F-Zu).Micro- and spectrofluorometric analysis (366nm excitation) were performed on cryostatic liver tissue sections and lipid extracts, and on fatty acids as pure compounds. The relative contribution of the different endogenous fluorophores to overall liver emission was estimated by a curve-fitting analysis procedure.Parallel biochemical (total lipids) and mass spectrometry (fatty acids) analysis were performed to support autofluorescence data interpretation. Results: Autofluorescence of NAD(P)H, flavin and lipofuscin-like lipopigments confirmed a higher oxidized state in MCD-WI than in L-Zu. Fluorescing fatty acids prevailed in Zucker than in Wistar rats, as confirmed by photobleaching results and oleic and arachidonic acid data from mass spectrometry. Nevertheless, normalization to the total lipid content indicated a relative higher fluorescent fatty acids in controls than in respective fatty livers, suggesting a different lipid turnover. Conclusion: Fluorescing fatty acids are expected to improve the diagnostic applications of autofluorescence analysis in experimental hepatology, with promising perspectives for application in lipotoxicity and disease progression studies, liver metabolic monitoring in the setting-up of preservation strategies and selection of suitable donor organs for transplantation.
FLUORESCING FATTY ACIDS IN LIVER AUTOFLUORESCENCE DIAGNOSIS
Croce Anna Cleta;Bottiroli Giovanni;
2016
Abstract
Background: Autofluorescence in hepatology is a promising insitu, diagnostic tool to detect diseases in real time and support the selection of donor organs for transplantation. In this concern, we aimed to investigate lipids as new autofluorescence biomarkers of liver metabolic alterations, since the changes in their accumulation and composition and excessive fatty acid trafficking are manifestation of metabolic syndrome and risk of disorder progression. We therefore characterized the autofluorescence of two diet induced or genetic fatty liver models with established redox metabolism differences, focusing on fluorescing fatty acids. Study: Fatty livers were from Wistar rats, administered with methionine/choline deficient diet (MCD-WI), or Zucker (fa/fa) rats (F-Zu).Micro- and spectrofluorometric analysis (366nm excitation) were performed on cryostatic liver tissue sections and lipid extracts, and on fatty acids as pure compounds. The relative contribution of the different endogenous fluorophores to overall liver emission was estimated by a curve-fitting analysis procedure.Parallel biochemical (total lipids) and mass spectrometry (fatty acids) analysis were performed to support autofluorescence data interpretation. Results: Autofluorescence of NAD(P)H, flavin and lipofuscin-like lipopigments confirmed a higher oxidized state in MCD-WI than in L-Zu. Fluorescing fatty acids prevailed in Zucker than in Wistar rats, as confirmed by photobleaching results and oleic and arachidonic acid data from mass spectrometry. Nevertheless, normalization to the total lipid content indicated a relative higher fluorescent fatty acids in controls than in respective fatty livers, suggesting a different lipid turnover. Conclusion: Fluorescing fatty acids are expected to improve the diagnostic applications of autofluorescence analysis in experimental hepatology, with promising perspectives for application in lipotoxicity and disease progression studies, liver metabolic monitoring in the setting-up of preservation strategies and selection of suitable donor organs for transplantation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
