Retinoids, retinoid analogs, and lactoferrin interact and differentially affect cell viability of 2 bovine mammary cell types in vitro.
Two bovine mammary cell types (BME-UV1 and MeBo cells) were used to evaluate the effect of natural retinoids, retinoid analogs, and bovine lactoferrin (bLf) on cell viability in vitro. Experiments with Alamar Blue showed a linear relationship between fluorescence and cell viability index. The BME-UV1 cells exhibited twice the metabolic activity but required half the doubling time of the MeBo cells. The BME-UV1 cells were very sensitive to all-trans retinoic acid (atRA) inhibition of cell viability (P<0.05) and exhibited a dose-dependent inhibition with 9-cisRA (9cRA; P<0.05). The MeBo cells exhibited some inhibition with these natural ligands (P<0.05), but they were not as sensitive. The addition of bLf had similar inhibitory effects (P<0.05) on cell viability of the 2 mammary cell types. Applications of RA receptor (RAR) agonist indicated that the stimulation of the RAR in both mammary cell types was highly effective in inhibition of cell viability (P<0.05), whereas the application of an RAR antagonist stimulated MeBo cell viability (P<0.05) and inhibited BME-UV1 cell viability (P<0.05). Finally, the use of the RAR antagonist in conjunction with bLf indicated a rescue of the bLf effect in the MeBo cells, suggesting that bLf is acting through the RAR receptor. Conversely, bLf reverted inhibition of cell viability by 9cRA in the BME-UV1 cell type (P<0.05). We conclude that RAR interaction in bovine mammary cell types regulates cell viability in vitro; we hypothesize that the natural ligands mediate regulation of bovine mammary cell viability in vivo and that bLf can either enhance or reverse the retinoid-induced inhibition of cell viability, depending on the type of bovine mammary cell studied.
Wang
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Department of Dairy and Animal Science, The Pennsylvania State University, University Park, PA 16802, USA.
Baumrucker
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D000818:Animals; D002417:Cattle; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects* / Q000502:physiology; D004347:Drug Interactions; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects; D005260:Female; D007202:Indicators and Reagents; D007781:Lactoferrin / Q000494:pharmacology*; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects*; D010078:Oxazines; D018168:Receptors, Retinoic Acid / Q000819:agonists / Q000037:antagonists & inhibitors / Q000187:drug effects; D012176:Retinoids / Q000494:pharmacology*; D014212:Tretinoin / Q000494:pharmacology; D014966:Xanthenes
D007202:Indicators and Reagents; D010078:Oxazines; D018168:Receptors, Retinoic Acid; D012176:Retinoids; D014966:Xanthenes; C005843:resazurin; D014212:Tretinoin; D007781:Lactoferrin