P-800 Autologous stem cell ovarian transplant induced long-lasting effects on the plasma proteome of women with premature ovarian insufficiency
Authors: Buigues A , Ramírez-Martin N , Martinez J , Pellicer N , Meseguer M , Pellicer A , Herraiz S 
Published: June 2023

Abstract

Study question
Does autologous stem cell ovarian transplant (ASCOT) induce any long-term modifications in the plasma proteomic profile of women with premature ovarian insufficiency (POI)?

Summary answer
Stem cell mobilization and infusion into the ovary elicit long-term proteomic changes in peripheral blood plasma composition in women with POI, reverting age-related proteomic changes.

What is known already
Patients with POI are challenging to treat, with oocyte donation remaining as the only feasible option to achieve pregnancy. Previous attempts to overcome the fertility problems of these patients have mainly been based on ovarian stimulation, and were likely unsuccessful due to the lack of stimulable antral follicles remaining in the ovaries. Our group described that ASCOT in patients with impaired ovarian function improves ovarian reserve biomarkers, follicle and oocyte quantity enabling pregnancy and delivery of healthy babies. Beneficial effects of ASCOT were associated with the presence of different stem-cell secreted factors in apheresis plasma.

Study design, size, duration
Experimental cohort study with plasma samples of POI women undergoing stem cell mobilization with granulocyte-colony stimulating factor (mobilization arm; N = 3) or stem cell mobilization and infusion into the ovarian artery (ASCOT arm; N = 3). Peripheral plasma samples were collected from all patients at recruitment (Pre), during bone marrow stem cell mobilization and collection by apheresis (Apheresis), and three months after mobilization or ASCOT (Post).

Participants/materials, setting, methods
Proteins were isolated from plasma samples and quantified by SWATHTM to compare the plasma proteomic profile of the different time points (Pre, Apheresis, Post), using an ElasticNet penalized linear regression method. To determine the biological processes affected by stem cell mobilization and infusion into the ovary, a Gene Ontology Enrichment Analysis for the differentially expressed proteins (DEPs) was performed, considering significantly enriched those GO Biological Processes with a False Discovery Rate &lt;0.05.

Main results and the role of chance
Discriminant analysis highlighted clear distinctions between the plasma proteome at the three evaluated time points. Both the stem cell mobilization and ASCOT technique induced statistically significant modifications in the plasma composition, reversing some age-related protein expression changes. Specifically, differences between Apheresis and Pre samples were explained by fourteen DEPs, revealing the functional analysis an enrichment in processes related to the complement cascade, immune system, and platelet degranulation. When the link of these proteomic changes with aging was evaluated, we found three proteins that were upregulated in Apheresis [C1QC, LYSC, LYAM1] whose plasma levels decrease with aging, and one downregulated protein [CRP] whose expression rises with age. Regarding Post samples, twenty-four DEPs with respect to Pre condition were found within the mobilization arm, being two of them linked with aging [MMP2 and ALDOC]. These DEPs were related with immune response and platelet degranulation but also with processes associated with responses to oxygen-containing compounds and growth hormones, and blood vessel maturation. Within the ASCOT arm, Pre and Post samples were clearly differentiated by eleven DEPs, although any GO Biological Process were found. Nevertheless, among these DEPs, we found DIAC which increases in plasma with aging and was downregulated after ASCOT.

Limitations, reasons for caution
Considering the small sample size used in this study, further experimental studies will be needed to validate the results. Moreover, further research will be necessary to determine the extent of the regenerative effects of the identified DEPs within the ovaries, and their direct implications in ovarian aging.

Wider implications of the findings
Our findings highlight the potential proteins and biological processes that may promote the follicle activation and growth observed after ASCOT. Identifying plasma proteins that regenerate aged or damaged ovaries could lead to more effective, targeted and/or preventive therapies for affected patients.
Funding: CIPROM/2021/058, PI21/00170, CP19/00141 and CD20/00116.

Trial registration number
NCT03535480