Progesterone-induced miR-133a inhibits the proliferation of endometrial epithelial cells.

AIM: This study aimed to understand the role of miR-133a in progesterone actions, explore the regulative mechanism of the progesterone receptor, and investigate the effects of miR-133a on the progesterone-inhibited proliferation of mouse endometrial epithelial cells. METHODS: The expression of miR-133a induced by progesterone was detected by quantitative real-time PCR both in vivo and in vitro. Ishikawa subcell lines stably transfected with progesterone receptor subtypes were used to determine the receptor mechanism of progesterone inducing miR-133a. Specific miR-133a mimics or inhibitors were transfected into mouse uteri and primary cultured endometrial epithelial cells to overexpress or downregulate the miR-133a. The roles of miR-133a in the cell cycle and proliferation of endometrial epithelial cells were analysed by flow cytometry and Edu incorporation analysis. The protein levels of cyclinD2 in uterine tissue sections and primary cultured endometrial epithelial cells were determined by immunohistochemistry and Western blot analysis. RESULTS: Progesterone could induce miR-133a expression in a PRB-dependent manner in endometrial epithelial cells. miR-133a inhibited endometrial epithelial cell proliferation by arresting cell cycle at the G1 -S transition. Moreover, miR-133a acted as an inhibitor in downregulating cyclinD2 in endometrial epithelial cells. CONCLUSION: We showed for the first time that progesterone-induced miR-133a inhibited the proliferation of endometrial epithelial cells by downregulating cyclinD2. Our research indicated an important mechanism for progesterone inhibiting the proliferation of endometrial epithelial cells by inducing special miRNAs to inhibit positive regulatory proteins in the cell cycle.

Prominent contribution of Th1, Th17, and Tregs to the host response during M. neoaurum infection.

Nontuberculous mycobacteria are ubiquitous in outside environment and animals. As for nontuberculous mycobacteria infection, there is only limited information in humans regarding infection and the subsequent immune response, especially for Mycobacterium neoaurum. Here, haematoxylin-eosin and Ziehl-Neelsen staining were used to observe pathological changes and detect acid-fast bacilli in organ samples in mouse model. Flow cytometry and quantitative real-time polymerase chain reaction were performed to analyze the contribution of Th1, Th17 and Tregs to the host immune response. M. neoaurum caused chronic infection in mice, resulting in infiltrates with large aggregates of inflammatory cells, especially macrophages, in lung tissues. Our results indicated that 72% of CD4+ T cells appeared in the early days of infection, which was followed by a decrease to 47% by day 32, and then a rise to 76% by day 56. Moreover, we found higher frequency of IFN-g-producing CD4+ T cells and elevated mRNA expression of the transcription factor T-bet in the lungs; however, we observed lower mRNA expression of the transcription factor RORgt and lower frequency of IL-17-producing CD4+ T cells. A transient relative decrease in the number of Treg cells was observed in the lungs; however, the number of Tregs did not change significantly between the first and last day following infection. Thus, M. neoaurum causes chronic infection in C57BL/6 mice, with Th1, Th17, and Tregs playing a prominent role in the host response. The present study may lay the basis for further studies on the mechanisms underlying infection with nontuberculous mycobacteria.

Progesterone-induced cyclin G1 inhibits the proliferation of endometrial epithelial cell and its possible molecular mechanism.

Under normal conditions, progesterone inhi-bits the estrogen-induced proliferation of endometrial epithelium. Our previous studies have shown that cyclin G1 was progesterone-dependent in mouse endometrial epithelium at peri-implantation, and exogenous cyclin G1 suppressed the proliferation of endometrial cancer cells. The objectives of this study are to determine whether cyclin G1, as a negative regulator of the cell cycle, is involved in the antiproliferative action of progesterone on endometrial epithelial cells, and to explore the possible molecular mechanism of cyclin G1 inhibition. The siRNA-mediated elimination of cyclin G1 attenuated the antiproliferative action of progesterone on endometrial epithelial cells. Immunoprecipitation showed that progesterone-induced cyclin G1 could interact with PP2A to mediate its phosphatase activity. The block of PP2A activity also attenuated the antiproliferative action of progesterone on endometrial epithelial cells and increased the phosphorylated Rb. In conclusion, progesterone-induced cyclin G1 mediates the inhibitory effect of progesterone on endometrial epithelial cell proliferation possibly through the recruitment of PP2A to dephosphorylate Rb.

Comparative study between slow freezing and vitrification of mouse embryos using different cryoprotectants.

The objective of this study was to evaluate the effects of different cryoprotectants and different cryopreservation protocols on the development of mouse eight-cell embryos. Mouse eight-cell embryos were cryopreserved by using propylene glycerol (PROH), ethylene glycerol (EG), dimethyl sulfoxide (DMSO) or glycerol (G) as cryoprotectant with slow-freezing or Vit-Master vitrification protocol. After thawing, the survival rate, blastocyst formation rate and blastocyst hatching rate of the embryos were compared. When the mouse eight-cell embryos were cryopreserved by the slow-freezing, the survival rate, the blastocyst formation rate and the blastocyst hatching rate of the embryos with PROH were significantly higher than those of DMSO and G (p < 0.05, respectively), but not significantly different among those of DMSO, G and EG (p > 0.05, respectively), and not significantly different between those of PROH and EG (p > 0.05, respectively). When the mouse eight-cell embryos were cryopreserved by Vit-Master vitrification, the survival rate, the blastocyst formation rate and the blastocyst hatching rate of the embryos with EG were significantly higher than those of PROH, DMSO and G (p < 0.05, respectively). Yet, there were no significant differences among those of PROH, DMSO and G (p > 0.05, respectively). In conclusion, PROH was the optimal cryoprotectant for the cryopreservation of mouse eight-cell embryos by slow-freezing protocol. EG was the optimal cryoprotectant for the cryopresevation of mouse eight-cell embryos by Vit-Master vitrification protocol, which may be commonly used in clinical and laboratory practice.