Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: February 28, 2003
Publication Date: April 4, 2003
Citation: Li, C., Elsasser, T.H. 2003. Induction of apoptosis by butyrate correlates with increasing level of protein ubiquitination in bovine kidney epithelial cells (MDBK) [abstract]. Journal of Animal Science. v. 81(1):249.
While butyrate (BT) is largely regarded as the minor short-chain fatty acid ([butyrate]< [acetate] or [proiponate]) formed during microbial fermatation in ruminants, an increasing body of evidence has clearly shown effects beyond those attributable to its function in nutrition. BT modulates cell differentiation, cell invasion, proteolysis, adhesion, proliferation, motility and in particular apoptosis. The body of information in the literature on these effects have concentrated on established cancer cell lines and on the epigenetic effects of physiologic concentrations of BT and other short-chain fatty acid. Effects of BT at the cellular and molecular level in normal bovine cells have not been studied thus far. The aim of this study was to investigate the effects of BT on the established bovine kidney epithelial cell line (MDBK) as a possible model for cell apoptosis. We also compared the effects of BT to those of a known inducer of apoptosis, the histone deacetylase inhibitor, trichostatin A (TSA). MDBK cells were obtained from the ATCC, grown in standard DMEM + 5% serum medium , passaged once every 3 days in a 1:10 split, and used at 50 % confluence. BT (0 to 10 mM) and TSA (0 to 200ng/ml) were added for an overnight incubation and cells were harvested for asessment of DNA fragmentation (agarose electrophoresis) and protein ubiquitination (western blot). Our results indicated that both BT and TSA induce apoptosis in MDBK cells in a dose-dependent maner (P<0.02, quadratic effect). Increased protein ubiquitination (P<0.05, linear) was detected in whole cell lysates from MDBK cells treated with BT and TSA suggesting a possible pathway through which cell apoptosis may be operating. These results indicate that the MDBK cell line is a useful in vitro model to study factors that impact apoptosis in the ruminant. The cells are responsive to butyrate in terms of both apoptosis and ubiquitination