Human placenta-derived mesenchymal stem cells stimulate ovarian function via miR-145 and bone morphogenetic protein signaling in aged rats.

BACKGROUND: Aging has detrimental effects on the ovary, such as a progressive reduction in fertility and decreased hormone production, that greatly reduce the quality of life of women. Thus, the current study was undertaken to investigate whether human placenta-derived mesenchymal stem cell (hPD-MSC) treatment can restore the decreases in folliculogenesis and ovarian function that occur with aging. METHODS: Acclimatized 52-week-old female SD rats were randomly divided into four groups: single hPD-MSC (5 × 105) therapy, multiple (three times, 10-day intervals) hPD-MSC therapy, control (PBS), and non-treated groups. hPD-MSC therapy was conducted by tail vein injection into aged rats. The rats were sacrificed 1, 2, 3, and 5 weeks after the last injection. hPD-MSC tracking and follicle numbers were histologically confirmed. The serum levels of sex hormones and circulating miRNAs were detected by ELISA and qRT-PCR, respectively. TGF-ß superfamily proteins and SMAD proteins in the ovary were detected by Western blot analysis. RESULTS: We observed that multiple transplantations of hPD-MSCs more effectively promoted primordial follicle activation and ovarian hormone (E2 and AMH) production than a single injection. After hPD-MSC therapy, the levels of miR-21-5p, miR-132-3p, and miR-212-3p, miRNAs associated with the ovarian reserve, were increased in the serum. Moreover, miRNAs (miR-16-5p, miR-34a-5p, and miR-191-5p) with known adverse effects on folliculogenesis were markedly suppressed. Importantly, the level of miR-145-5p was reduced after single- or multiple-injection hPD-MSC therapy, and we confirmed that miR-145-5p targets Bmpr2 but not Tgfbr2. Interestingly, downregulation of miR-145-5p led to an increase in BMPR2, and activation of SMAD signaling concurrently increased primordial follicle development and the number of primary and antral follicles. CONCLUSIONS: Our study verified that multiple intravenous injections of hPD-MSCs led to improved ovarian function via miR-145-5p and BMP-SMAD signaling and proposed the future therapeutic potential of hPD-MSCs to promote ovarian function in women at advanced age to improve their quality of life during climacterium.

Peripheral blood NK cell cytotoxicities are negatively correlated with CD8(+) T cells in fertile women but not in women with a history of recurrent pregnancy loss.

PROBLEM: We aim to investigate NK cell cytolytic activities and its relationship to other lymphocyte subsets in peripheral blood of women with a history of recurrent pregnancy loss (RPL). METHODS OF STUDY: Women with a history of RPL (n = 48) comprised RPL group, and 15 fertile women served as controls. Lymphocyte subsets such as T (CD3(+)), T helper (CD3(+)/4(+)), cytotoxic T (CD3(+)/8(+)), NK (CD3(-)/56(+)), and peripheral blood NK cell cytolytic activities at three different effector to target cell ratios (E/T ratio, 50:1, 25:1 and 12.5:1) are measured by flow cytometric analysis. RESULTS: Peripheral blood NK cell levels are significantly increased in women with RPL as compared to controls (P = 0.001). NK cell cytolytic activities in RPL group are significantly increased as compared to those of controls at E/T ratio of 50:1 (42.5 ± 16.3 versus 29.9 ± 13.8, P = 0.009), 25:1 (31.6 ± 15.0 versus 19.4 ± 10.1, P = 0.004), and 12.5:1 (20.1 ± 10.9 versus 12.3 ± 7.5, P = 0.011). In RPL group, peripheral blood NK cell levels (%) showed a significant positive correlation with NK cell cytolytic activities at E/T ratio of 50:1 (r = 0.522, P < 0.001), 25:1 (r = 0.588, P < 0.001), and 12.5:1 (r = 0.604, P < 0.001). In controls, CD3(+)/8(+) cells (%) show a negative correlation with NK cell cytolytic activities at E/T ratio of 50:1 (r = -0.566, P = 0.028), 25:1 (r = -0.60., P = 0.017), and 12.5:1 (r = -0.602, P = 0.018). Ratios of T-helper cell to T-cytotoxic cell are positively correlated with NK cell cytolytic activities at E/T ratio of 50:1 (r = 0.601, P = 0.018), 25:1 (r = 0.632, P = 0.012), and 12.5:1 (r = 0.637, P = 0.011). CONCLUSION: NK cell-mediated immunopathology plays a role in RPL. Women with RPL have a disrupted immune regulation between cytotoxic T and NK cells. Failure of immune modulation by CD8(+) T cells may exert NK cell activation and reproductive failures in women with RPL.