Show simple item record

dc.contributor.supervisor Burczynski,Frank J (Pharmacy) en
dc.contributor.author Yan, Jing
dc.date.accessioned 2010-06-09T13:39:51Z
dc.date.available 2010-06-09T13:39:51Z
dc.date.issued 2010-06-09T13:39:51Z
dc.identifier.citation Yan, Jing (2009). Journal of Lipid Research, Vol. 50, 2445-2454 en
dc.identifier.uri http://hdl.handle.net/1993/3998
dc.description.abstract Liver fatty acid binding protein (L-FABP) binds and translocates many lipophilic substrates within the cytoplasm including long chain fatty acids. Moreover it was reported that L-FABP possesses antioxidative properties within hepatocytes. However, the mechanism of L-FABP’s antioxidative activity remains to be determined. Peroxisome proliferator activated receptor (PPAR) agonists and antagonists can regulate L-FABP levels. However, it needs to be investigated how PPAR agonists and antagonists regulate L-FABP expression. And whether the altered expression of L-FABP by these agents will affect its antioxidative properties within hepatocytes remains unclear. In this thesis we employed clofibrate (PPARα agonist), MK886 (PPARα antagonist), and GW9662 (PPARγ antagonist) to elucidate the mechanism whereby PPAR regulate L-FABP expression and what effect such expression has on the antioxidant activity of L-FABP in CRL-1548 hepatoma cells. Clofibrate served to upregulate L-FABP expression while MK886 and GW9662 were employed to inhibit L-FABP expression. The principal findings revealed that clofibrate treatment enhanced L-FABP mRNA stability and transcription, which resulted in increased L-FABP levels, while MK866 and GW9662 reduced these levels. We also demonstrated that increases in L-FABP levels were associated with reduced cytosolic reactive oxygen species (ROS), while L-FABP siRNA knockdown resulted in a decrease in L-FABP expression and an associated increase in ROS levels. The antioxidant mechanism of recombinant rat L-FABP in the presence of a hydrophilic (AAPH) and lipophilic (AMVN) free radical generators was also evaluated. Recombinant rat L-FABP was produced in E. coli and its amino acid sequence was confirmed by MALDI QqTOF MS. Antioxidant activity was assayed using the thiobarbituric acid method. Ascorbic acid served as a positive control for the AAPH reaction while α-tocopherol was used as a positive control for the AMVN reaction. The antioxidant activity of recombinant L-FABP was greater when free radicals were generated with AAPH than AMVN. Oxidative modification of L-FABP included up to five methionine oxidative peptides with a total of 80 Da mass shift compared to native L-FABP. These findings suggest that the mechanism of L-FABP’s antioxidant activity involved the reaction of methionine with free radicals. In conclusion, L-FABP expression is regulated by PPAR agonists and antagonists through transcription and mRNA stability. Moreover, methionine residues appear to play an important role in the antioxidative activity of L-FABP. en
dc.format.extent 2949571 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject liver fatty acid binding protein en
dc.subject antioxidant en
dc.title Antioxidative Function of Liver Fatty Acid Binding Protein en
dc.type info:eu-repo/semantics/doctoralThesis
dc.type doctoral thesis en_US
dc.degree.discipline Pharmacy en
dc.contributor.examiningcommittee Gong, Yuewen (Pharmacy) Siow, Chris (Physiology) Luxon, Bruce A (University of Iowa) en
dc.degree.level Doctor of Philosophy (Ph.D.) en
dc.description.note October 2010 en


Files in this item

This item appears in the following Collection(s)

Show simple item record

View Statistics