Background: Oxidative stress in fatty and/or ischemic livers plays a major role in the risk of hepatic failure development and progression. Autofluorescence-based Optical Biopsy (AF-OB), already successfully applied for liver function monitoring, is investigated as a minimally-invasive diagnostic procedure for the monitoring of oxidative stress, in particular with reference to application in surgery and recruitment of marginal donor organs in transplantation. Study: Livers with increasing fat content (Male Wistar rats, 1-9 weeks of methionine/choline deficient -MCD- diet vs controls) were submitted to AF-OB and spectral fitting analysis (exc. 366 nm) in vivo via fiber optic probe, or on cryostatic tissue sections, to estimate the AF contribution of endogenous fluorophores involved in redox reactions (NAD(P)H, flavins, fatty acids, vitamin A). Lipid content and composition were defined by means of Nile red fluorochromization, and lipid peroxidation (TBARS), GSH, ATP, ATP/ADP levels measured by biochemical assays. Results: As compared to controls, fatty livers show a red shift of AF spectra soon after 1 week of MCD diet, indicating a decrease in the relative contribution of NAD(P)H with respect to vitamin A and fatty acids, in turn accounting for a strong photolability of tissue vesicles. Consistently, a marked increase in both polar and apolar lipids is revealed by Nile red spectra. At 1 MCD week both GSH and ATP levels are markedly decreased, while lipid peroxidation increases slightly after 2 weeks, becoming strongly significant at 4 weeks, when, in parallel, a shoulder in the 500- 600nm AF emission region, reflecting and increase in oxidized lipids, becomes very evident. Conclusion: The early changes in liver tissue AF properties observed in parallel with those of lipids and energetic and antioxidant markers confirm the potential of AF-OB analysis for a real time fatty liver oxidative stress detection and monitoring.
INTEGRATED AUTOFLUORESCENCE OPTICAL BIOPSY, OXIDATIVE STRESS AND FATTY GRADATION IN MODIFIED-DIET LIVER MODEL
Croce Anna Cleta;
2014
Abstract
Background: Oxidative stress in fatty and/or ischemic livers plays a major role in the risk of hepatic failure development and progression. Autofluorescence-based Optical Biopsy (AF-OB), already successfully applied for liver function monitoring, is investigated as a minimally-invasive diagnostic procedure for the monitoring of oxidative stress, in particular with reference to application in surgery and recruitment of marginal donor organs in transplantation. Study: Livers with increasing fat content (Male Wistar rats, 1-9 weeks of methionine/choline deficient -MCD- diet vs controls) were submitted to AF-OB and spectral fitting analysis (exc. 366 nm) in vivo via fiber optic probe, or on cryostatic tissue sections, to estimate the AF contribution of endogenous fluorophores involved in redox reactions (NAD(P)H, flavins, fatty acids, vitamin A). Lipid content and composition were defined by means of Nile red fluorochromization, and lipid peroxidation (TBARS), GSH, ATP, ATP/ADP levels measured by biochemical assays. Results: As compared to controls, fatty livers show a red shift of AF spectra soon after 1 week of MCD diet, indicating a decrease in the relative contribution of NAD(P)H with respect to vitamin A and fatty acids, in turn accounting for a strong photolability of tissue vesicles. Consistently, a marked increase in both polar and apolar lipids is revealed by Nile red spectra. At 1 MCD week both GSH and ATP levels are markedly decreased, while lipid peroxidation increases slightly after 2 weeks, becoming strongly significant at 4 weeks, when, in parallel, a shoulder in the 500- 600nm AF emission region, reflecting and increase in oxidized lipids, becomes very evident. Conclusion: The early changes in liver tissue AF properties observed in parallel with those of lipids and energetic and antioxidant markers confirm the potential of AF-OB analysis for a real time fatty liver oxidative stress detection and monitoring.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
