Is Atrial Natriuretic Peptide (ANP) and Natriuretic Peptide Receptor-A (NPR-A) Expression in Human Placenta and Decidua Normal?

BACKGROUND Atrial natriuretic peptide (ANP) is a cardiac hormone that regulates blood pressure and the salt-water balance in the blood. It acts through natriuretic peptide receptors (NPR), and the major biologically active ANP receptor is natriuretic peptide receptor-A (NPR-A). Aberrant forms of ANP and its receptors have been reported in patients with preeclampsia. However, whether aberrant forms of ANP or NPR-A are present in preeclamptic placenta, and what their role is in preeclampsia pathogenesis, has not yet been elucidated clearly. The aim of this study was to assess the expression of ANP and NPR-A in the placenta and decidua and its role in preeclampsia development. MATERIAL AND METHODS The expression of ANP and NPR-A in the first-trimester villous and decidua, full-term placenta, and preeclamptic placenta was determined using immunohistochemistry and Western blot analysis. The HTR8/SVneo cell line was used to investigate the role of NPR-A in proliferation, apoptosis, and invasion using Cell Counting Kit-8 analysis, flow cytometry analysis, and a Transwell invasion assay, respectively. RESULTS ANP and NPR-A were localized in the syncytiotrophoblasts, cytotrophoblasts, and trophoblast columns of human first-trimester villous trophoblast cells of decidua, and in the glandular epithelium and extravillous trophoblast cells of decidua. ANP-positive and NPR-A-positive cells in the decidual stroma were clustered around and infiltrated into the vascular wall of the spiral artery undergoing remodeling. NPR-A expression was significantly reduced in preeclamptic placentas, and NPR-A knockdown significantly impaired the invasion ability of HTR8/SVneo cells, although it had no effect on cell proliferation and apoptosis. CONCLUSIONS ANP and NPR-A are involved in human placental development. Decreased levels of NPR-A may contribute to the development of preeclampsia.

[Role of macrophages in mouse uterine during the peri-implantation period].

OBJECTIVE: To investigate the effect of macrophages on embryo implantation by observing the distribution of macrophages in mouse uterine tissues during the peri-implantation period. METHODS: Uterine tissues were collected from pregnant (n=30) and pseudopregnant mice (n=30) during the peri-implantation period. The distributions of macrophages, iNOS and leukemia inhibitory factor (LIF) were determined by immunohistochemistry and the correlations of macrophages with iNOS and LIF were analyzed. RESULTS: Macrophages were located mainly in the endometrium before D4.5 in the pregnant rats with D0.5 defined as the morning when a vaginal plug was observed. After D4.5, the macrophages was significantly reduced in number (P<0.05) in the endometrium and gradually migrated to the perimetrium. In the psudopregnant mice, macrophages were located mainly in the endometrium. Before D4.5, iNOS-positive cells were detected mainly in the endometrium and the myometrium in the pregnant rats and became significantly reduced on D4.5 (P<0.05); in the pseudopregnant mice, the positive cells were mostly detected in the endometrium. Significant differences were found in the distribution of the macrophages and LIF between the implantation and non-implantation sites (P=0.013). LIF was mostly located in the endometrium in the pregnant mice but scarcely detected in the pseudopregnant mice. CONCLUSION: Macrophages are located mainly in the endometrium and the implantation site where iNOS and LIF are expressed, suggesting the important role of macrophages in the determination of implantation.

[Outcomes of in vitro fertilization-embryo transfer and intracytoplasmic sperm injection for non-male infertility patients with a low number of oocytes retrieved].

OBJECTIVE: To compare the outcomes of in vitro fertilization-embryo transfer (IVF) and intracytoplasmic sperm injection (ICSI) in non-male infertility patients with a low number of oocytes retrieved and provide evidences for defining the indications of ICSI. METHODS: A retrospective analysis was conducted among 220 non-male infertility patients with a low number of oocyte retrieved(≤5) including 151 receiving IVF and 69 undergoing ICSI. The baseline characteristics, ovary response index, fertilization results, embryo quality and clinical outcomes were compared between the 2 groups. RESULTS: Although the fertilization rates, normal fertilization rates, complete fertilization failure rates, cleavage rates, good embryo rates, implantation rates and clinical pregnancy rates showed no significant differences between the 2 groups, the complete fertilization failure rates tended to decrease and the other indices tended to increase in IVF group. CONCLUSIONS: ICSI can not improve the fertilization results, embryonic development potential or clinical outcomes in non-male infertility patients with a low number of oocytes retrieved, and is therefore not recommended for these patients.