Effects of the conditioned medium of mesenchymal stem cells on mouse oocyte activation and development

In vitro maturation medium supplementation: utilization of repaglinide, L-carnitine, and mesenchymal stem cell-conditioned medium to improve developmental competence of oocytes derived from endometriosis mouse models

Endometriosis (EMS) is one of the most prevalent causes for female infertility. Herein, we investigated the effect of the repaglinide (RG), L-carnitine (LC), and bone marrow mesenchymal stem cell-conditioned medium (BMSC-CM) supplementation during in vitro maturation (IVM) on the quality, maturation, and fertilization rates, as well as embryonic quality and development of oocytes derived from normal and EMS mouse model. Immature oocytes were collected from two groups of normal and EMS-induced female NMRI mice at 6-8 weeks of age. Oocytes were cultured in IVM medium unsupplemented (control group), or supplemented with 1 M RG, 0.3 and 0.6 mg/mL LC, and 25 and 50% BMSC-CM. After 24 h of oocyte incubation, IVM rate and antioxidant status were assessed. Subsequently, the rates of fertilization, cleavage, blastulation, and embryonic development were assessed. Our results demonstrated that supplementation of IVM medium with LC and BMSC-CM, especially 50% BMSC-CM, significantly enhanced IVM and fertilization rates, and markedly improved blastocyst development and total blastocyst cell numbers in EMS-induced mice compared to the control group (53.28±0.24 vs 18.09±0.10%). Additionally, LC and BMSC-CM were able to significantly modulate EMS-induced nitro-oxidative stress by boosting total antioxidant capacity (TAC) and mitigating nitric oxide (NO) levels. Collectively, LC and BMSC-CM supplementation improved oocyte quality and IVM rates, pre-implantation developmental competence of oocytes after in vitro fertilization, and enhanced total blastocyst cell numbers probably by attenuating nitro-oxidative stress and accelerating nuclear maturation of oocytes. These outcomes may provide novel approaches to refining the IVM conditions that can advance the efficiency of assisted reproductive technologies in infertile couples.

Isolation and characterization mesenchymal stem cells from red panda (Ailurus fulgens styani) endometrium

Endometrial mesenchymal stem cells (eMSCs) are undifferentiated endometrial cells with self-renewal, multidirectional differentiation and high proliferation potential. Nowadays, eMSCs have been found in a few species, but it has never been reported in endangered wild animals, especially the red panda. In this study, we successfully isolated and characterized the eMSCs derived from red panda. Red panda eMSCs were fibroblast-like, had a strong proliferative potential and a stable chromosome number. Pluripotency genes including Klf4, Sox2 and Thy1 were highly expressed in eMSCs. Besides, cultured eMSCs were positive for MSC markers CD44, CD49f and CD105 and negative for endothelial cell marker CD31 and haematopoietic cell marker CD34. Moreover, no reference RNA-seq was used to analyse the eMSCs transcriptional expression profile and key pathways. Compared with skin fibroblast cell group, 9104 differentially expressed genes (DEGs) were identified, among which are 5034 genes upregulated, 4070 genes downregulated and the top 20 enrichment pathways of DEGs in Gene Ontology (GO) and the Kyoto Encyclopedia of Genes Genomes (KEGG) mainly associated with G-protein coupled receptor signalling pathway, carbohydrate derivative binding, nucleoside binding, ribosome biogenesis, cell cycle, DNA replication, Ras signalling pathway and purine metabolism. Among the DEGs, some representative genes about promoting MSCs differentiation and proliferation were upregulated and promoting fibroblasts proliferation were downregulated in eMSCs group. Red panda eMSCs also had multiple differentiation ability and could differentiate into adipocytes, chondrocytes and hepatocytes. In conclusion, we, for the first time, isolated and characterized the red panda eMSCs with ability of multiplication and multilineage differentiation in vitro. The new multipotential stem cell could be beneficial not only for the germ plasm resources conservation of red panda, but also for basic or pre-clinical studies in the future.

Human amniotic membrane stem cells' conditioned medium has better support for in-vitro production of bovine embryos than FBS

Apart from oocyte quality, the media used has a significant effect on the production and quality of blastocysts produced in vitro. This study was designed to evaluate the replacement of serum with human amniotic membrane stem cells' conditioned medium (hAMSCs-CM) during bovine embryo culture on the quantity and quality of produced blastocysts. The in-vitro-produced embryos on the third day of IVC were randomly divided into the following culture groups: SOFaa + 5% FBS (Control), SOFaa + 5% hAMSCs-CM (5% CM), SOFaa + 2.5% hAMSCs-CM + 2.5% FBS (2.5% CM) and SOFaa + hAMSC co-culture (co-culture). The blastocyst and hatching rates, blastocyst cells number (the number of trophectoderm, inner cell mass and total cells), and the expression of some developmentally important genes (OCT4, PLAC8 and COX2 genes) in the treated groups, especially in the 5% CM, compared to the control had improved (p < .05). No significant difference was observed between groups for viability and hatching rate in vitrified-warmed blastocysts. Due to the positive effect of hAMSCs' conditioned medium (hAMSCs-CM) on blastocyst production, as well as its ease of preparation and the need to avoid the transmission of microbial contamination to the culture medium, hAMSCs-CM can be used as a suitable alternative to FBS during 3 to 8 days of bovine embryo culture.

Improvement of oocyte in vitro maturation from mice with polycystic ovary syndrome by human mesenchymal stromal cell-conditioned media

The outcome of in vitro maturation (IVM) in the patients with polycystic ovary syndrome (PCOS) is poor. Abnormal intraovarian paracrine interplay alters microenvironment for oocyte development through folliculogenesis and decreases developmental competence of oocytes in patients with PCOS. Mesenchymal stromal cells (MSCs) secrete a variety of cytokines and growth factors that could promote oocyte maturation in vitro. Thus, in the current study we aimed to evaluate the effect of human bone marrow MSC-conditioned media (hBM-MSC-CM), as a supplement, to enrich IVM medium for PCOS germinal vesicles (GVs). For this purpose, oocytes at GV and metaphase II (MII) stages were harvested from PCOS mice. The GVs were randomly divided into four groups and incubated for 24 hours in an IVM medium (TCM199, as the control group) or TCM199 supplemented by 25%, 50%, and 75% of hBM-MSC-CM (PCOS-CM25, PCOS-CM50, and PCOS-CM75 groups, respectively) so as to evaluate which dose(s) could enhance maturation rate of the GVs and their subsequent in vitro fertilization (IVF) outcome. Furthermore, MII oocytes and their subsequent IVF outcome were considered as the in vivo matured (PCOS-IVO) group. The data showed that supplementation of IVM medium with 50% hBM-MSC-CM significantly increased cytoplasmic and nuclear maturation of the GVs (P < 0.001), and also fertilization and two-cell rate (P < 0.001) and blastocyst formation (P < 0.01) of in vitro matured oocytes from mice with PCOS. Overall, higher oocyte maturation and fertilization outcome in PCOS-CM50 group proposed that enrichment of IVM medium with hBM-MSC-CM could be considered as a promising approach to improve IVM of PCOS oocytes.