Effect of adipose-derived mesenchymal stem cell transplantation on cyclophosphamide-induced ovarian damage in rats

Abstract

To explore the effect of adipose-derived mesenchymal stem cells (ADMSCs) on ovarian damage induced by cyclophosphamide (CTX) and its mechanism. Methods: ADMSCs isolated from adipose tissue of female SD rats were cultured and divided into a blank group and a CTX group (n=15 in each group). CTX (75 mg/kg) was injected intraperitoneally to establish a model of ovarian damage in rats. A total of 45 female SD rats were also divided into 3 groups: Group A (15 rats, only injected intraperitoneally with 75 mg/kg CTX diluted with 1 mL 0.9% saline), Group B [15 rats, injected intraperitoneally with 75 mg/kg CTX diluted with 1 mL 0.9% saline, after 4 estrus cycles, injected 0.6 mL ADMSCs (6×105 cells) by the tail vein], and Group C [15 rats, injected intraperitoneally with 75 mg/kg CTX diluted with 1 mL 0.9% saline, after 4 estrus cycles, injected 40 mL ADMSCs (20 mL per side, 2×104 cells) in situ ovarian]. After 4 estrus cycles, the changes of quality of life, ponderal growth were recorded, the sex hormone levels [estradiol (E2), follicle-stimulating hormone (FSH)] were tested by ELISA, and the morphology of ovarian tissue and follicle count were observed by HE staining. The expression of BMP-15, Bcl-2 and Bax in ovarian tissues were tested by immunohistochemistry, real-time PCR or Western blotting. The apoptosis rate of follicular cells was detected by TdT-mediated dUTP nick end labeling (TUNEL) assay. Results: After transplantation of ADMSCs, compared with the Group A, their quality of life of rats in the Group B and C was improved, and the ponderal growth was increased (both P<0.01). Compared with the Group A, the serum E2 levels in the Group B and the Group C were increased (P<0.01, P<0.05), and the FSH levels in the Group B and C were decreased (both P<0.01). The granular cell layer, the number of corpus lutein and the count of various grade follicles were significantly increased, and many new follicles and mature oocytes were observed in the Group B and C. Compared with Group A, the count of primitive follicles, sinusoidal follicles, pre-ovulation follicles and total follicles, and pre-sinusoidal follicles were dramatically increased in the Group B. The follicle at all levels count was increased in the Group C than that in the Group A (all P<0.01). Comparing with the Group A, the expressions of BMP-15 and Bcl-2 were increased (all P<0.01), the expressions of Bax was decreased (both P<0.01), and the apoptosis rates of follicular cells were decreased in the Group B and C (both P<0.01). However, there was no difference between the Group B and the Group C in the above indexes (all P>0.05). Conclusion: ADMSCs transplantation can effectively repair ovarian damage induced by CTX in rats, which may be achieved by inhibiting mitochondrial apoptosis of granulosa cells.