Evaluation of the hormonal and molecular pathways involved in maintaining the corpus luteum of pregnancy in lactating dairy cows

• Grant number: 13/17801-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: October 10, 2013
• End date: April 09, 2014
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: João Carlos Pinheiro Ferreira
• Grantee: Eduardo Trevisol
• Supervisor: Milo C. Wiltbank
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: University of Wisconsin-Madison (UW-Madison), United States
• Associated to the scholarship: 11/20449-7 - Role of LH during induced luteolysis and characterization of luteal sensitivity to PGF2alpha during estrus cycle and treatment with IFNt, BP.DR

Abstract

It is well established that P4 from the CL is essential for maintenance of pregnancy and that the early embryo produces interferon-tau, which is essential for changes in uterine and CL gene expression that results in continued function of the CL during pregnancy (Dorniak et al., 2013, Spencer et al., 2007b). However, there has recently been substantial controversy regarding the precise endocrine pathways involved in maintenance of the CL by interferon-tau with three potential pathways being most supported. First, the classical mechanism is that interferon-tau changes uterine gene expression resulting in reduced pulses of PGF and thus lack of luteolysis (Danet-Desnoyers et al., 1994, Dorniak et al., 2013, Knickerbocker et al., 1986, Spencer et al., 2007a, Thatcher et al., 1984). Second, interferon-tau increases uterine production of PGEs (PGE1 and PGE2) and PGE blocks the action of PGF at the CL, maintaining CL function (Krishnaswamy et al., 2009, Lee et al., 2012, Weems et al., 2011, Weems et al., 2012). Third, recent convincing evidence demonstrates that interferon-tau exits the uterine lumen and interacts directly with the CL and there are some data that it may directly block PGF action at the CL (Antoniazzi et al., 2011, Antoniazzi et al., 2013, Bott et al., 2010, Gifford et al., 2007, Hansen et al., 2010, Oliveira et al., 2008). It is essential to differentiate the roles for these three pathways in order to provide the basis for rationally developing methods to enhance the process of CL maintenance during early pregnancy. (AU)