TY - JOUR
T1 - Roadmap to pregnancy during the period of maternal recognition in the cow
T2 - Changes within the corpus luteum associated with luteal rescue
AU - Pate, Joy L.
N1 - Funding Information:
Funding for the author was provided by Agriculture and Food Research Initiative Competitive Grant no. 2016-67015-24900 from the USDA National Institute of Food and Agriculture , Multistate Project NE 1727 , and the C. Lee Rumberger and Family Chair in Agricultural Sciences Endowment.
Funding Information:
In studies from various laboratories, differences in CL of pregnancy and CL of the estrous cycle have been observed. Magata et al. [68] compared selected mRNA in bovine CL from D 29 to 33 of pregnancy to midcycle (D 10 to 13) CL. None of the mRNA measured by qPCR were less abundant in the CL of pregnancy, but genes associated with steroidogenesis, prostaglandin synthesis and immune response were in greater abundance in the CL of pregnancy. There was also greater abundance of mRNA for VEGFR3, a growth factor that stimulated lymphangiogenesis. This supports earlier work from this group showing that lymphangiogenesis occurred in the bovine CL of early pregnancy, due to upregulation of VEGFR3, which is stimulated by IFNT [69]. In early pregnancy (D 20 to 25), the bovine CL contains a greater abundance of mRNA and protein related to PGE synthesis, but less oxytocin, whereas in later pregnancy (D150 to 160) there is an increase in the chemokines eotaxin and lymphotactin [70,71]. Analysis of mRNA abundance in bovine CL also indicated that there may be activation of cellular survival pathways in the CL of pregnancy compared to that of the cycle [72]. Recently, there has been renewed interest in the role of lipids as regulators of luteal function. Hughes et al. [73] compared a panel of lipids in D18 CL of pregnancy and the cycle and found one lipid, 15-KETE, to be less abundant in the CL of pregnancy, although four other lipids tended to be less. Integration of these five lipids with the mRNA profiled in the D17 CL described above [66] indicated a role in immune cell chemotaxis and cell-cell communication. Further, three of the five lipids that were different or tended to be different on D18 also decreased when D18 CL of pregnancy were compared to D 11 of the estrous cycle, indicating that they may be downregulated during early pregnancy [73]. In a similar study of CL from cyclic and pregnant cattle on D 16, three different lipids varied, and pathway analysis indicated potential roles in cellular proliferation and vasodilation [74]. It is difficult to reconcile differences between these two studies, which could be due to day of tissue collection, handling of tissue or most importantly, diet of the animals, among other factors. It should be noted that in both studies, large variations in lipid concentrations were reported. There will likely be expanded research on lipid regulators of luteal function in the near future, and it may be very important for researchers to carefully control diet and other factors that can alter lipid concentrations and metabolism in the animals, and perhaps increase sample size to limit the effect of animal to animal variation.Funding for the author was provided by Agriculture and Food Research Initiative Competitive Grant no. 2016-67015-24900 from the USDA National Institute of Food and Agriculture, Multistate Project NE 1727, and the C. Lee Rumberger and Family Chair in Agricultural Sciences Endowment.
Publisher Copyright:
© 2020 Elsevier Inc.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - A viable corpus luteum (CL) producing an adequate amount of progesterone is absolutely essential for establishment and maintenance of pregnancy. One function of embryonic signaling to the mother is to ensure that the CL is maintained. In ruminants, the secretion of uterine prostaglandin F2alpha (PGF2A) is the signal that initiates luteolysis. Despite many studies to determine if PGF2A secretion from the uterus is altered in early pregnancy, conflicting interpretations have led to controversy regarding the exact mechanisms by which maternal recognition of pregnancy is achieved. In addition to alteration of uterine prostaglandin metabolism, changes within the CL itself may facilitate the establishment of a successful pregnancy. These changes include alteration of luteal blood flow, prostaglandin metabolism, sensitivity to prostaglandin actions, increased steroidogenic capacity, significant intracellular molecular changes and modification of the immune cells that are within the CL. Whether these intraluteal changes are necessary to establish pregnancy is undetermined. The focus of this review will be to provide a brief historical perspective on the utero-ovarian relationships that regulate luteal lifespan and review current knowledge of the CL of pregnancy in sheep and cattle.
AB - A viable corpus luteum (CL) producing an adequate amount of progesterone is absolutely essential for establishment and maintenance of pregnancy. One function of embryonic signaling to the mother is to ensure that the CL is maintained. In ruminants, the secretion of uterine prostaglandin F2alpha (PGF2A) is the signal that initiates luteolysis. Despite many studies to determine if PGF2A secretion from the uterus is altered in early pregnancy, conflicting interpretations have led to controversy regarding the exact mechanisms by which maternal recognition of pregnancy is achieved. In addition to alteration of uterine prostaglandin metabolism, changes within the CL itself may facilitate the establishment of a successful pregnancy. These changes include alteration of luteal blood flow, prostaglandin metabolism, sensitivity to prostaglandin actions, increased steroidogenic capacity, significant intracellular molecular changes and modification of the immune cells that are within the CL. Whether these intraluteal changes are necessary to establish pregnancy is undetermined. The focus of this review will be to provide a brief historical perspective on the utero-ovarian relationships that regulate luteal lifespan and review current knowledge of the CL of pregnancy in sheep and cattle.
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U2 - 10.1016/j.theriogenology.2020.01.074
DO - 10.1016/j.theriogenology.2020.01.074
M3 - Article
C2 - 32115247
AN - SCOPUS:85080036083
SN - 0093-691X
VL - 150
SP - 294
EP - 301
JO - Theriogenology
JF - Theriogenology
ER -