Intraovarian injection of 3D-MSC-EVs-ECM gel significantly improved rat ovarian function after chemotherapy.

Background: Restoring the function of the ovary is important for chemotherapy-induced ovarian failure (COF) patients. Stem cell and extracellular vesicles (EVs) therapy show promise but need further improvement. Methods: Human umbilical cord mesenchymal stem cells (hUC-MSCs) were primarily cultured and further three-dimensional (3D) cultured using an ultra-low attachment surface method. The expression levels of nutritional cytokines and immunomodulatory and stemness-related genes of 3D-cultured hUC-MSCs were analyzed. EVs were isolated by ultracentrifugation and characterized. Ovaries were decellularized with sodium dodecyl sulfate to obtain extracellular matrix (ECM). Lyophilized EVs from three-dimensional (2D) or 3D hUC-MSCs were mixed with ECM to prepare the 2D/3D-MSC-EVs-ECM gels. The therapeutic effect of the MSC-EVs-ECM gel on cyclophosphamide (CTX) -treated rats was analyzed through various tests. RNA sequencing was used to analyze the expression changes of genes before and after treatment. Results: After culturing in ultra-low attachment dishes, hUC-MSCs aggregated into spheroids and significantly upregulated the expression levels of immunomodulatory and stemness-related genes. The total EVs yield was also upregulated (5.6-fold) after 3D culture. The cell viability of CTX-treated ovarian granulosa cells (OGCs) was significantly rescued by coculture with the 3D-MSC-EVs-ECM gel. Hormones indicative of ovarian function, AMH, E2, and FSH, were recovered in both the CTX + 2D-MSC-EVs-ECM gel group and the CTX + 3D-MSC-EVs-ECM gel group, while the apoptosis-related protein Bax was significantly downregulated. The 3D-MSC-EVs-ECM gel was more effective than the 2D-MSC-EVs-ECM gel. Significantly differentially expressed genes, such as Hbb-b1, Gpd1, and Sirpa, were detected by RNA sequencing. Hbb-b1 was increased in the ovaries of CTX-treated rats, and this increase was attenuated by injecting the 2D/3D-MSC-EVs-ECM gel. Gpd1 was increased after CTX treatment, and this increase was reversed by the 3D-MSC-EVs-ECM gel. Sirpa was decreased in the ovaries of CTX-treated rats, and this decrease was attenuated by injecting the 3D-MSC-EVs-ECM gel. Conclusions: Our study demonstrated that the 3D-MSC-EVs-ECM gel is an efficient strategy for the recovery of ovarian function in CTX-induced ovarian failure. [ABSTRACT FROM AUTHOR]