BMSCs Regulates The Aged-oocyte Development And Quality In Vitro

Part? The effects of BMSCs on the aged-oocyte development and quality in miceObjectives: To observe the effect of BMSCs on the maturation and 2-cell rates of aged mouse oocyte in vitro.Methods: We collected germinal vesicle(GV)oocytes from 36-38 weeks aged mouse.BMSCs co-culture with GV oocytes in vitro in the transwell chamber.Under the same condition,we used the untreated oocytes from old mice as Old Group and untreated oocytes from young mice as Young group.We detected the maturation rates and 2-cell rates of oocytes.The quality of oocytes by observing the shape and the location of spindle in MII oocytes was evaluated.Results: The maturation rate in Co-culture group(74.4%)was significantly higher than that in Old group(57.0%)(P<0.01),but lower than that in Young group(82.8%)(P<0.01).The fertilization rate in Co-culture group(77.9%)was still significantly higher than that in Old group(60.4%)(P<0.01),but lower than that in Young group(87.6%)(P<0.01).In the Old group,the morphology of spindle was abnormal,such as the microtubules arranged irregularly.In BMSCs co-culture group(32.89%),we found the abnormal spindle rate was significantly lower than that in Old group(49.73%)(P<0.01),but still higher than that in Young group(21.00%)(P<0.01).Conclusion: The maturation rate and fertility rate in Co-culture group were significantly increased than that in Old group.These results indicated BMSCs dramatically influenced the development and quality of aged oocytes.The change of rate of spindle morphology also indicated that BMSCs influenced oocyte meiosis severely.Part? The mechanism of BMSCs regulating the maturation and quality of aged-oocyteObjective: To observe the effect of BMSCs on Mfn2 expression and mitochondrial function in old mice oocytes,and detect the mechanism of BMSCs regulating the maturation and quality.Method: We collected germinal vesicle(GV)oocytes from 36-38 weeks aged mouse.BMSCs co-culture with GV oocytes in vitro in the transwell chamber.Under the same condition,we used the untreated oocytes from old mice as Old Group and untreated oocytes from young mice as Young group.We detected the expression of Mfn2 by Q-PCR and Western Blot.We detected the mt DNA relative expression by using Q-PCR.In addition,after oocytes in vitro maturation 16 hours,the distribution of mitochondria was observed with mito-tracker green and membrane potential was detected with JC-1 dye.Results: The Mfn2 m RNA and protein levels in Co-culture group were significantly higher than that in Old group(P<0.01),but lower than that in Young group(P<0.01).Mitochondria proliferation in Co-culture group was also significantly higher than that in Old group(P<0.01).In Co-culture group,mitochondrial membrane potential was significantly higher than Old group(P<0.01).We found the distribution of mitochondria was almost abnormal in Old group,such as abnormally clustered distributed in cytoplasm of the oocyte,however,in BMSCs co-culture group(73.67%),we found the abnormal rate of mitochondria distribution was significantly lower than that in Old group(56.54%)(P<0.01),but higher than that in Young group(23.13%)(P<0.01).Conclusion: BMSCs can regulate the mitochondrial structure and function of aged-oocytes by activating the expression of Mfn2,thereby improving the development and quality of old mouse oocytes.