Felipe Vilella, PhD | Carlos Simón, M.D, PhDPhD Student:
Leslie B. Ramírez | Juan Manuel Moreno MoyaLab Technician:
Immunohistochemistry of human endometrium showing positive staining for prostaglandin synthetase mPGES1. The endometrium on LH +2 shows an strong labeling for this protein in endometrial epithelial (EE), glandular epithelium (GE) and stroma, while LH +7 staining intensity decreases in all structures, disappearing almost completely in the stroma.
Initiation of pregnancy is a multi event process that begins with the fecundation of the oocyte by sperm and subsequent migration of the newly formed embryo to the uterus, where it must implant onto the endometrium to initiate pregnancy. Successful implantation is absolutely dependent on the acquisition of a receptive state by the endometrium prior to embryo attachment. In humans, this is achieved only during a short period of time between days 19-23 of the menstrual cycle, the so-called window of implantation.
In the last decades a delay in the age of paternity among couples has occurred, mainly in developed countries. These changes have result in an increase of infertility in society. For that reason the study of the molecular mechanisms that regulates the achievement of a receptive endometrium has recently become a matter of intense research. After a treatment using steroids, a large number of mediators and structural factors have been identified as possible markers of potential endometrial receptivity, like endometrial pinopodes, adhesion molecules as integrins, cytokines, growth factors and lipids among others. Moreover, the use of genetics and proteomics have provided new tools for the evaluation of endometrial receptivity, while histological samples from endometrial biopsies have been used to identify molecules related to uterine receptivity. However, these approaches have not given results applicable on daily clinical practice for in vitro fertilization (IVF) treatments yet, since none specific factor has been identified to be essential for implantation in humans. Therefore, there are major drawbacks in putting into practice the use of biopsies because of its invasiveness, and because it alters the end point of implantation which in turn hampers the extrapolation of the results obtained for the next cycle.
In the endometrial receptivity laboratory we plan to use the analysis of endometrial secretions to help to study endometrial receptivity, still important to emphasize that endometrial aspiration of the fluid does not affect pregnancy rates. This secretomic approach provides reliable data of individual molecules that can be correlated with the days of the cycle, opening, therefore, a new field of study for the analysis of the changes experienced by the endometrium during the menstrual cycle maintaining a non-invasive approach.
- Vilella F, Ramirez LB, Simón C. Lipidomics as an emerging tool to predict endometrial receptivity. Fertil Steril. 2013 Mar 15;99(4):1100-6.
- Berlanga O, Bradshaw HB, Vilella-Mitjana F, Garrido-Gómez T, Simón C. How endometrial secretomics can help in predicting implantation. Placenta. 2011 Sep;32 Suppl 3:S271-5.
Published book Chapters
- Leslie B Ramirez, Sebastian Martinez y Felipe Vilella. Perfil lipidomico de la receptividade endometrial. In Colección: CUADERNOS DE MEDICINA REPRODUCTIVA (Número 3, Volumen 19, Año 2013). In press.
- Maria Ruiz-Alonso, Felipe Vilella, David Blesa, Carlos Simón. Genomics and secretomics of endometrial receptivity. clinical translation. In Human Reproduction. 2013; In press.
- Tamara Garrido-Gomez, Francisco Dominguez, Maria Ruiz, Felipe Vilella, and Carlos Simon. The analysis of endometrial receptivity. Textbook of assisted reproductive techniques: laboratory perspectives. informa healthcare; edición: 4th revised edition (27 de junio de 2012) 2012; 366-379.