Role of secretory protease inhibitor SPINK3 in mouse uterus during early pregnancy.

Successful embryo implantation depends on intricate epithelial-stromal cross-talk. However, molecular modulators involved in this cellular communication remain poorly elucidated. Using multiple approaches, we have investigated the spatiotemporal expression and regulation of serine protease inhibitor Kazal type 3 (SPINK3) in mouse uterus during the estrous cycle and early pregnancy. In cycling mice, both SPINK3 mRNA and protein are only expressed during proestrus. In the pregnant mouse, the expression levels of both SPINK3 mRNA and protein increase on days 5-8 and then decline. Spink3 mRNA is expressed exclusively in the uterine glandular epithelium, whereas SPINK3 protein is localized on the surface of both luminal and glandular epithelium and in the decidua. Moreover, SPINK3 in the decidua has been observed in the primary decidual zone on day 6 and the secondary decidual zone on days 7-8; this is tightly associated with the progression of decidualization. SPINK3 has also been found in decidual cells of the artificially decidualized uterine horn but not control horn, whereas Spink3 mRNA localizes in the glands of both horns. The expression of endometrial Spink3 is not regulated by the blastocyst according to its expression pattern during pseudopregnancy and delayed implantation but is induced by progesterone and further augmented by a combination of progesterone and estrogen in ovariectomized mice. Thus, uterine-gland-derived SPINK3, as a new paracrine modulator, might play an important role in embryo implantation through its influence on stromal decidualization in mice.

[Progress in tumor cell invasion].

Tumor cell invasion and metastasis are the most complicated problems of cancer medicine and cancer biology, and cancer becomes a fatal disease because of cancer cell invasion and metastasis. The mechanisms of invasion and metastasis remain elusive, but tumor cell invasion still is the hotspot of research. This review summarizes the development of researching in tumor cell invasion.

Evidence for the inhibition of fertilization in vitro by anti-ZP3 antisera derived from DNA vaccine.

Previously we have found that DNA vaccine, pCMV4-rZPC' can generate specific antibodies against rabbit ZPC (amino acid 263-415, rZPC'), which binds to ovarian ZP and leads to a significant reduction of fertility in vivo. The purpose of this study was to evaluate the effect of antisera from pCMV4-rZPC(')-immunized mice on sperm-oocyte interaction in vitro. The effect of antisera from DNA vaccine-immunized mice on fertilization and early embryonic development was studied using an in vitro fertilization system. The results showed that the antisera supplemented in fertilization medium (10%, v/v) significantly decreased the rate of fertilization compared to that of control groups (P<0.05); whereas the antisera showed no significant effect on the rate of fertilization when ZP-free eggs were used. Moreover, the antisera pre-neutralized with mouse soluble zona pellucida lost the capacity to inhibit fertilization when compared with that of control groups. In addition, the antisera showed no detrimental effect on early developmental potential of mouse embryos in vitro. Taken together, our study provided herein direct evidence showing that antisera generated by DNA vaccine can block sperm-egg recognition during fertilization via targeting the oocyte ZP proteins.

Estradiol-regulated proline-rich acid protein 1 is repressed by class I histone deacetylase and functions in peri-implantation mouse uterus.

Secretory protein proline-rich acid protein 1 (PRAP1) is abundantly expressed in late pregnant uterus. However, regulation and function of PRAP1 in pregnant uterus is still elusive. We firstly reported differential expression of PRAP1 in peri-implantation uteri and its localization in endometrial epithelia. Expression of PRAP1 in uterus was induced by 17ß-estradiol and its expression showed a negative correlation with that of class Ihistone deacetylases (HDACs) in isolated endometrial epithelia. PRAP1 was increased by HDACs inhibitor sodium butyrate treatment, while decreased significantly by estrogen receptor inhibitor ICI182,780 via up-regulating class IHDACs. Number of implanted embryos was decreased in mice immunized with pCR3.1-PRAP1 or injected with rabbit anti-PRAP1 antibody. DNA immunization or antibody injection could affect apoptosis and expression of cytokines (IL-4, IFN-γ). In conclusion, both 17ß-estradiol and class IHDACs are involved in modulating PRAP1 expression in peri-implantation uteri. Preliminary functional research indicates that neutralizing PRAP1 protein causes reduction of implanted embryos.

Effects of TGF beta-1 on mouse embryo implantation and expression of H2-D1 and H2-DM.

We investigated the mechanism that TGF-beta1 influences the immuno-environment at maternal-fetal interface and affects embryo implantation, using mouse uterine horn injection model. The expression of MHC I antigen (H2-D1) and the chaperone of MHC II antigen (H2-DM) after anti-TGF-beta1 antibody or hrTGF-beta1 treated pregnant mice were examined by real-time PCR, western blotting and immunohistochemistry. The results showed that the number of implanted embryos of anti-TGF-beta1 antibody-treated mice was decreased compared with the control. The expression of H2-D1 and H2-DM on days 6 and 7 treated uteri was increased both at mRNA and protein levels. In hrTGF-beta1 treated group, the expression of H2-D1 and H2-DM protein was decreased, and the number of implanted embryos was slightly increased. Immunohistochemical studies revealed that H2-D1 and H2-DM were mainly localized to the primary decidual zone. The anti-TGF-beta1 antibody and exogenous hrTGF-beta1 treatment altered the intensity of H2-D1 and H2-DM signal but did not change their localization. These observations suggested that injection of anti-TGF-beta1 antibody affected the number of mouse embryo implantation, and regulated the expression of H2-DM and H2-Q10.