Expression of vascular endothelial growth factor in rat ovary during pregnancy and postpartum.

The expressions of vascular endothelial growth factor (VEGF) in rat ovarian follicles and corpus luteum (CL) during different stages of pregnancy and postpartum were investigated. In addition, the effect of tumor necrosis factor-alpha (TNF-alpha) on VEGF expression was examined. VEGF mRNA was localized in granulosa cells of preantral follicles, as well as in the granulosa and theca cells of small antral follicles, but not in large antral follicles.

Expression and regulation of Dickkopf2 during periimplantation in mice.

Successful implantation depends on active dialogue between the maternal endometrium and the implanting blastocysts that is well controlled by groups of regulators at the molecular level. Dickkopf2 (Dkk2) is a member of Dickkopf family normally acting as an antagonist of canonical Wnt/beta-catenin signaling, which has been proven to participate in tumorigenesis and early embryo development. In order to explore the potential function of Dkk2 in embryo implantation, the present study investigated the uterine expression and regulation profiles of Dkk2 during periimplantation in mice.

Effects of Wnt proteins on cell proliferation and apoptosis in HEK293 cells.

Wnt proteins and Wnt signalings have been implicated in a variety of development and cell processes, while aberrant activation of Wnt signaling is linked to a range of cancers in many tissues. In this study, we used the HEK293 cell line to investigate the effects of Wnt3a and Wnt5a on proliferation and apoptosis in a serum starvation culture. After Wnt3a and Wnt5a proteins were expressed, they both promoted the proliferation of HEK293 cells under serum starvation.

[Changing trends of the expression of TIMP-4 in mouse ovary during pregnant and postpartum period].

Aim: The changes of tissue inhibitor of metalloproteinase-4 (TIMP-4) expression in mouse ovary during pregnant and postpartum period were studied to investigate the role of TIMP-4 in corpus luteum (CL).

Methods: RT-PCR was used to deter mine the change of TIMP-4 mRNA and indirect immunofluorescence was used to observe the change of TIMP-4 protein. The expression of TIMP-4 mRNA was observed in various periods throughout the stage of pregnancy and postpartum day 1.

Dickkopf-1 secreted by decidual cells promotes trophoblast cell invasion during murine placentation.

Dickkopf-1 (Dkk1) is one of the secreted antagonists in the canonical Wnt signaling pathway. It plays important roles in diverse developmental processes. However, the role of Dkk1 in trophoblast cell invasion during placentation remains unclear.

Gonadotropin stimulation of ovarian fractalkine expression and fractalkine augmentation of progesterone biosynthesis by luteinizing granulosa cells.

Recent studies indicated that ovarian functions are regulated by diverse paracrine factors induced by the preovulatory increases in circulating LH. Based on DNA microarray analyses and real-time RT-PCR, we found a major increase in the transcript levels of a chemokine fractalkine after human chorionic gonadotropin (hCG) treatment during the preovulatory period in gonadotropin-primed immature mice and rats. Although CX3CR1, the seven-transmembrane receptor for fractalkine, was also found in murine ovaries, its transcripts displayed minimal changes.

Nucleoside analogue reverse transcriptase inhibitors differentially inhibit human LINE-1 retrotransposition.

Background: Intact LINE-1 elements are the only retrotransposons encoded by the human genome known to be capable of autonomous replication. Numerous cases of genetic disease have been traced to gene disruptions caused by LINE-1 retrotransposition events in germ-line cells. In addition, genomic instability resulting from LINE-1 retrotransposition in somatic cells has been proposed as a contributing factor to oncogenesis and to cancer progression.

Effects of Wnt3a on proliferation and differentiation of human epidermal stem cells.

Epidermal stem cells maintain development and homeostasis of mammalian epidermis throughout life. However, the molecular mechanisms involved in the proliferation and differentiation of epidermal stem cells are far from clear. In this study, we investigated the effects of Wnt3a and Wnt/beta-catenin signaling on proliferation and differentiation of human fetal epidermal stem cells.

Enrichment of putative human epidermal stem cells based on cell size and collagen type IV adhesiveness.

The enrichment and identification of human epidermal stem cells (EpSCs) are of paramount importance for both basic research and clinical application. Although several approaches for the enrichment of EpSCs have been established, enriching a pure population of viable EpSCs is still a challenging task. An improved approach is worth developing to enhance the purity and viability of EpSCs.

Roles of Dickkopf-1 and its receptor Kremen1 during embryonic implantation in mice.

Objective: To determine the roles of Dickkopf-1 (Dkk1) in mouse embryo implantation.

Design: Experimental prospective study.

Setting: Animal research and institute laboratory facility.

Nitric oxide affects preimplantation embryonic development in a rotating wall vessel bioreactor simulating microgravity.

Microgravity was simulated with a rotating wall vessel bioreactor (RWVB) in order to study its effect on pre-implantation embryonic development in mice. Three experimental groups were used: stationary control, rotational control and clinostat rotation. Three experiments were performed as follows.

Dickkopf-1 induced apoptosis in human placental choriocarcinoma is independent of canonical Wnt signaling.

Placental choriocarcinoma, a reproductive system carcinoma in women, has about 0.81% occurrence frequency in China, which leads to over 90% lethality due to indistinct pathogenesis and the absence of efficient therapeutic treatment. In the present study, using immunostaining and reverse transcription PCR, we reported that Dickkopf-1 (Dkk-1) is prominently expressed in human cytotrophoblast (CTB) cell, but absent in the human placental choriocarcinoma cell line JAR and JEG3, implicating an unknown correlation between Dkk-1 and carcinogenesis of placental choriocarcinoma.

Developmental and hormonal regulation of meltrin beta (ADAM19) expression in mouse testes during embryonic and postnatal life.

More than half of ADAM (a disintegrin and metalloprotease) family members are expressed in mammalian male reproductive organs such as testis and epididymis. The ADAM19 gene identified in mouse is a member of the ADAM family and is highly enriched in testes of a newborn mouse. The present study was performed to determine its expression pattern in whole mouse testes in vivo as well as its in vitro action and regulation in testis cells from 2-day-old mice.

Localization and temporal regulation of tissue inhibitor of metalloproteinases-4 in mouse ovary.

Tissue inhibitors of metalloproteinases (TIMPs) are potential regulators of tissue remodeling in the ovary. The aim of the present study was to examine the localization and temporal regulation of TIMP-4 protein in the mouse ovary. An induced superovulation model (eCG/hCG) was employed in immature mice to evaluate TIMP-4 protein expression profiles in ovaries collected during the follicular phase, the pre ovulatory period, and the luteal lifespan.

Role of sonic hedgehog in maintaining a pool of proliferating stem cells in the human fetal epidermis.

Background: The mammalian epidermis is maintained by the ongoing proliferation of a subpopulation of keratinocytes known as epidermal stem cells. Sonic hedgehog (Shh) can regulate morphogenesis of hair follicles and several types of skin cancer, but the effect of Shh on proliferation of human putative epidermal stem cells (HPESCs) is poorly understood.

Methods And Results: We first found that Shh, its receptors Patched1 (Ptc1) as well as Smoothened (Smo) and its downstream transcription factor Gli-1 were expressed in the basal layer of human fetal epidermis and freshly sorted HPESCs.

Tetraspanin CD9 regulates invasion during mouse embryo implantation.

The expression of tetraspanin CD9 was found on blastocysts in mice and endometrium epithelial cells in human and bovine. However, it remains unknown how CD9 is involved in the precise dialogue between embryo and uterus during early pregnancy. This study was designed to investigate the functional roles of CD9 in the embryo implantation with monoclonal antibody against CD9 protein (anti-CD9 mAb) and antisense oligonucleotide against CD9 gene (AS-CD9).

Expression and hormonal regulation of calcyclin-binding protein (CacyBP) in the mouse uterus during early pregnancy.

Calcyclin-binding protein (Siah-1-Interacting Protein, CacyBP/SIP), is a calcium signaling protein involved in the degradation of beta-catenin, however, little is known about its role in reproductive biology. The present study was to character its temporospatial expression pattern and regulation in mouse uterus and to investigate whether it plays a role in the regulation of normal endometrial events. While prominently expressed in both luminal and glandular epithelia, CacyBP underwent dynamic changes during early pregnancy.

Leptin-directed embryo implantation: leptin regulates adhesion and outgrowth of mouse blastocysts and receptivity of endometrial epithelial cells.

Leptin is a 16-kDa multifunctional protein. Recent reports indicate that leptin is an important molecule during implantation and placentation, implicated in embryonic-maternal cross-talk and cytotrophoblast invasiveness, however, the role of leptin playing in the process of normal blastocyst implantation has not been well characterized. In the present study, the possible mechanisms of leptin playing in mouse blastocyst implantation were investigated.

Generation and characterization of pluripotent stem cells from cloned bovine embryos.

Bovine embryonic stem (ES) cell lines reported to date vary in morphology and marker expression (e.g., alkaline phosphatase [ALPL], stage-specific embryonic antigen 4 [SSEA4], and OCT4) that normally are associated with the undifferentiated, pluripotent state.

A model for implantation: coculture of blastocysts and uterine endometrium in mice.

One of the limitations in embryo implantation research is the lack of an available in vitro model that faithfully replicates embryo-uterine interactions. In previous studies, embryos were cultured on a monolayer of either uterine epithelial cells or extracellular matrix substratum on which embryos could adhere and outgrow. However, these models failed to display embryonic invasion, primarily because of the shortage of critical structural and molecular supports that are available in vivo.

Inhibition of the beta-catenin signaling pathway in blastocyst and uterus during the window of implantation in mice.

Beta-catenin, the mammalian homolog of Drosophila armadillo protein, was first identified as a cadherin-associated protein at cell-cell junctions. Another function of beta-catenin is the transduction of cytosolic signals to the nucleus in a variety of cellular contexts, which usually are elicited by the active form of beta-catenin. The aim of the present study was to examine the potential role of active beta-catenin in the mouse embryo and uterus during embryo implantation.

Enrichment and characterization of mouse putative epidermal stem cells.

Epidermis, a continuously renewing tissue, is maintained by stem cells that proliferate and replenish worn out or damaged cells in the tissue during life. Cultured epidermal stem cells have great potential in scientific research and clinical application. However, isolating a pure and viable population of epidermal stem cells and culturing them has been challenging.

Enrichment and identification of human 'fetal' epidermal stem cells.

Background: Human epidermis, a continuously renewing tissue, is maintained throughout life by stem cells that proliferate and replenish worn-out or damaged cells in the tissue. Cultured human epidermal stem cells have great potential in clinical application. However, isolating and culturing a pure population of epidermal stem cells has proven to be challenging.

Effects of fibronectin, VEGF and angiostatin on the expression of MMPs through different signaling pathways in the JEG-3 cells.

Problem: The objective of this study was to evaluate the possible signal pathway of fibronectin (FN), vascular endothelial growth factor (VEGF) and angiostatin (AS) on the expression of matrix metalloproteinases (MMPs) in JEG-3 cells.

Methods Of Study: JEG-3 cells were cultured and were examined for the effect of FN, VEGF and AS on the expression of MMPs by immunocytochemistry, gelatin zymography, Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR).

Results: We found that up-regulation of the expression of MMPs was induced by FN and VEGF through the focal adhesion kinase (FAK)/mitogen-activated protein kinase (MAPK) and Flt-1/p38SAPK/MAPKAPK2 signaling pathways, respectively.