Metabolomic profiling and biochemical evaluation of the follicular fluid of endometriosis patients

Diseases are complex systems that can be studied through the integration of data derived from different disciplines to obtain a global and reliable picture of the biological phenomenon under investigation. Based on the recent observations that the metabolomics profiling of follicular fluids reflects the ovarian microenvironment of women and that endometriosis represents an example of complex diseases, clearly diagnosed by laparoscopy, we thought that the follicular fluids of endometriosis patients can represent a study model to evaluate the possibility of integrating data obtained by different approaches. Hence, the aim of this work was to analyze and integrate different clinical chemistry parameters with specific reference to the metabolic profile, inflammatory state and cell damage by a 1H-NMR approach and biochemical analysis in the follicular fluids of women with different stages of endometriosis (I-II and III-IV) subjected to the In Vitro Fertilization (IVF) cycle. Our analysis evidenced that in the follicular fluids of endometriosis patients the levels of phospholipids, lactate, insulin, PTX3, CXCL8, CXCL10, CCL11 and VEGF were higher whereas those of some fatty acids, lysine, choline, glucose, aspartate, alanine, leucine, valine, proline, phosphocholine, total LDH as well its LDH-3 isoform were lower in comparison to the control group. The levels of LDHB, PTX3 and insulin receptor were also confirmed by RT-PCR applied on cumulus cells surrounding oocytes retrieved from the patients. The reduced oocyte quality observed in patients with endometriosis can be certainly correlated to the different levels of these molecules. These data represent how the integration of different experimental approaches may be useful for understanding the underlying mechanisms of a complex disease and can lead to a better clinical management of endometriosis.