title: Elevated non-esterified fatty acid concentrations hamper bovine oviductal epithelial cell physiology in three different in vitro culture systems.
abstract: Elevated non-esterified fatty acids (NEFAs) have been recognized as an important link between lipolytic metabolic conditions and impaired fertility in high-yielding dairy cows. However, NEFA effects on the oviductal micro-environment currently remain unknown. We hypothesize that elevated NEFAs may contribute to the complex pathology of subfertility by exerting a negative effect on bovine oviductal epithelial cell (BOEC) physiology. Therefore, the objectives of this study were to elucidate direct NEFA effects on BOEC physiology in three different in vitro cell culture systems. Bovine oviductal epithelial cells (four replicates) were mechanically isolated, pooled, and cultured as conventional monolayers, as explants, and in a polarized cell culture system with Dulbecco's modified Eagle's medium/F12-based culture medium. Bovine oviductal epithelial cells were exposed to an NEFA mixture of oleic, stearic, and palmitic acids for 24 hours at both physiological and pathologic concentrations. A control (0 μM NEFA) and a solvent control (0 μM NEFA + 0.45% ethanol) group were implemented. Bovine oviductal epithelial cells physiology was assessed by means of cell number and viability, a sperm binding assay, transepithelial electric resistance (TER), and a wound-healing assay. Bovine oviductal epithelial cell morphology was assessed by scanning electron microscopy on cell polarity, presence of microvilli and cilia, and monolayer integrity. Bovine oviductal epithelial cell number was negatively affected by increasing NEFAs, however, cell viability was not. Sperm binding affinity significantly decreased with increasing NEFAs and tended (P = 0.051) to be more affected by the direction of NEFA exposure in the polarized cell culture system. The absolute TER increase after NEFA exposure in the control (110 ± 11 Ω.cm(2)) was significantly higher than that in all the other treatments and was also different depending on the exposure side. Bidirectional exposed monolayers were even associated with a significant TER reduction (-15 ± 10 Ω.cm(2); P < 0.05). Cell proliferation capacity showed a decreased cell migration with increasing NEFA concentrations but was irrespective of the exposure side. Bovine oviductal epithelial cell morphology was not affected. In conclusion, in an in vitro setting, NEFAs exert a negative effect on BOEC physiology but not morphology. Ultimately, these physiological alterations in its microenvironment may result in suboptimal development of the pre-implantation embryo and a reduced reproductive outcome in dairy cattle.
authors.affiliation: Laboratory for Veterinary Physiology and Biochemistry, Gamete Research Center, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium. Electronic address: lies.jordaens@uantwerpen.be.
authors.forename: L
authors.initials: L
authors.lastname: Jordaens
authors.affiliation: Departamento de Producción Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Arias-Alvarez
authors.affiliation: Department of Veterinary Sciences, Laboratory for Cell Biology and Histology, Core Facility for Biomedical Microscopic Imaging, University of Antwerp, Antwerp, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: Pintelon
authors.affiliation: Department of Veterinary Sciences, Laboratory for Cell Biology and Histology, Core Facility for Biomedical Microscopic Imaging, University of Antwerp, Antwerp, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Thys
authors.affiliation: Laboratory for Veterinary Physiology and Biochemistry, Gamete Research Center, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Valckx
authors.affiliation: Laboratory for Veterinary Physiology and Biochemistry, Gamete Research Center, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium.
authors.forename: Y
authors.initials: Y
authors.lastname: Dezhkam
authors.affiliation: Laboratory for Veterinary Physiology and Biochemistry, Gamete Research Center, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium.
authors.forename: P E J
authors.initials: PE
authors.lastname: Bols
authors.affiliation: Laboratory for Veterinary Physiology and Biochemistry, Gamete Research Center, Department of Veterinary Sciences, University of Antwerp, Wilrijk, Belgium.
authors.forename: J L M R
authors.initials: JL
authors.lastname: Leroy
mesh_terms: D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques / Q000662:veterinary; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D060833:Cellular Microenvironment; D017097:Electric Impedance; D047108:Embryonic Development; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology; D005187:Fallopian Tubes / Q000166:cytology*; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D005260:Female; D007150:Immunohistochemistry; D008855:Microscopy, Electron, Scanning; D014945:Wound Healing / Q000187:drug effects
chemical_list: D005230:Fatty Acids, Nonesterified
keywords: Bovine oviduct; Fatty acid; Maternal metabolism; Subfertility