Expression of factors associated with apoptosis in the porcine corpus luteum throughout the luteal phase of the estrous cycle and early pregnancy: Their possible involvement in acquisition of luteolytic sensitivity

• Published in: Theriogenology 2015-03, Vol.83 (4), p.535-545
• Main Authors: Przygrodzka, E., Witek, K.J., Kaczmarek, M.M., Andronowska, A., Ziecik, A.J.
• Format: Article
• Language: English
• Subjects: Acquisition of luteolytic sensitivity; Animals; Apoptosis; Apoptosis - physiology; Corpus Luteum - cytology; Corpus Luteum - physiology; Estrous Cycle - physiology; Female; Gene Expression Regulation - physiology; Luteal Phase - physiology; Pig; Pregnancy; Pregnancy, Animal - physiology; Progesterone - blood; RNA, Messenger - genetics; RNA, Messenger - metabolism; Swine - physiology
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2014.10.016

The studies on the acquisition of luteolytic sensitivity have been focused mainly on molecular changes induced in the luteal tissue after treatment with exogenous PGF2α or on physiological changes occurring during the estrous cycle. The comparison of changes leading to the acquisition of luteolytic sensitivity after Day 12 of the estrous cycle and corresponding days of pregnancy has not been investigated in the pig. The present study was undertaken to evaluate (1) apoptosis measured as the proportions of early apoptotic, late apoptotic, and viable cells; (2) expression of factors involved in the extrinsic (TNFA/TNFα, TNFRSF1A/TNFR1, TNFRSF1B/TNFR2, FAS/Fas, and FASLG/FasL) and intrinsic (CASP3/Casp3, TP53/p-53, BAX/Bax, and BCL2/Bcl-2) apoptotic pathways, with two components of the activating protein-1 complex, i.e., FOS/Fos and JUN/Jun and IFNG/IFNγ; and (3) concentrations of luteal and blood plasma progesterone (P4) throughout the luteal phase of the estrous cycle and early pregnancy. Corpora lutea (CL) were collected postmortem on Days 8, 10, 12, and 14 of the estrous cycle and the corresponding days of pregnancy. The luteal tissue was subjected to RNA and/or protein isolation and disaggregation of CL cells followed by flow cytometry analysis aimed to determine apoptotic changes. Luteal and blood plasma P4 concentrations decreased on Day 14 of the estrous cycle versus pregnancy (P