Knockdown of regulator of G-protein signalling 2 (Rgs2) leads to abnormal early mouse embryo development in vitro.

Regulator of G-protein signalling 2 (Rgs2) is involved in G-protein-mediated signalling by negatively regulating the activity of the G-protein α-subunit. In the present study, the expression patterns of Rgs2 in mouse ovarian tissues and early embryos were determined by semiquantitative reverse transcription-polymerase chain reaction, immunohistochemistry and immunofluorescent analyses. Rgs2 expression was observed in the ovarian tissues of adult female mice, with an almost equal expression levels during different stages of the oestrous cycle. Rgs2 was abundant in the cytoplasm, membrane, nuclei and spindles of intact polar bodies in mouse early embryos at different developmental stages from the zygote to blastocyst. The effect of Rgs2 knockdown on early embryonic development in vitro was examined by microinjecting Rgs2-specific short interfering (si) RNAs into mouse zygotes. Knockdown of endogenous Rgs2 expression led to abnormal embryonic development in vitro, with a considerable number of early embryos arrested at the 2- or 4-cell stage. Moreover, mRNA expression of three zygotic gene activation-related genes (i.e. Zscan4, Tcstv1 and MuERV-L) was decreased significantly in 2-cell arrested embryos. These results suggest that Rgs2 plays a critical role in early embryo development.

Digital capability and green innovation: The perspective of green supply chain collaboration and top management's environmental awareness.

The emergence of the digital economy has accelerated digital transformation, and digitalization has shown new potential and solutions to increasingly severe environmental challenges. Based on the resource-based view, dynamic capability view, synergy effect and upper echelons theory, the connotation and measurement dimensions of digital capability and green supply chain collaboration are defined and improved. Then, a theoretical model of "digital capability-green supply chain collaboration-green innovation performance" is constructed. The influence mechanism and transmission process of digital capability on green innovation performance from the perspective of green supply chain collaboration is discussed. Meanwhile, the boundary condition of the influence of digital capability on green innovation performance in the view of top management's environmental awareness is explored. Finally, an empirical test is conducted based on the Chinese manufacturing corporates. The results indicate that green innovation performance is significantly and favorably impacted by digital capability, green supply chain collaboration plays a partial mediating role between digital capability and green innovation performance, and top management's environmental awareness can positively moderate the effect of digital capability on green innovation performance. This study offers valuable theoretical and practical enlightenments for manufacturing companies to foster the growth of green innovation through digital capability more effectively.

PTOV1 is associated with UCH-L1 and in response to estrogen stimuli during the mouse oocyte development.

To investigate the biological significance of ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) involvement in oocyte maturation, we screened for proteins that bound to UCH-L1 in mouse ovaries, and we found that the prostate tumor overexpressed-1 (PTOV1) protein was able to bind to UCH-L1. PTOV1 is highly expressed in prostate cancers and considered as a potential marker for carcinogenesis and the progress of prostate cancer. It was reported that PTOV1 plays an important role in cell cycle regulation, but its role in mammalian oocyte development and meiosis is still unclear. In this paper, it was found that the expression levels of PTOV1 in mouse ovaries progressively increased from prepubescence to adulthood. And we found by immunohistochemistry that PTOV1 spreaded in both the cytoplasm and nuclei of oocytes during prepuberty, but in normal adult mouse oocytes, it concentrated not only in nuclei but also on the plasma membrane, though in some oocytes with abnormal shapes, PTOV1 did not display the typical distribution patterns. In granulosa cells, however, it was found to locate in the cytoplasm at all the selected ages. In postnatal mouse ovaries (28 days), estradiol treatment induced the adult-specific distribution pattern of PTOV1 in oocytes. In addition, UCH-L1 was shown to be associated with CDK1, which participated in the regulation of cell cycle and oocyte maturation. Therefore, we propose that the distribution changes of PTOV1 are age-dependent, and significant for mouse oocyte development and maturation. Moreover, the discovery that PTOV1 is associated with UCH-L1 in mouse oocytes supports the explanations for that UCH-L1 is involved in oocyte development and maturation, especially under the regulation of estrogen.

Evaluation of the immunogenicity of a single chain chimeric peptide composed of hCGß and oLHα for inhibition of the growth of hCGß-expressing cancer cells.

Human chorionic gonadotropin (hCG) is a membrane-associated protein highly expressed in several types of human cancer cells. The expression in the cancer cells indicates that hCG may be a potential target molecule for cancer immunotherapy. The objective of this study was to develop a novel immunogenic molecule, which can efficiently induce the neutralizing antibody against hCG and which is also suitable for mass production. The immunogenicity of the recombinant single chain chimeric protein of hCGß-oLHα expressed by yeast was examined. Additionally, the inhibitory effects of the anti-hCGß-oLHα antibody on the growth of hCG-positive cancer cells were determined. It was found that hCGß-oLHα yielded high titers of anti-hCG rabbit antibody that could effectively neutralize the bioactivity of hCG. The rabbit anti-hCGß-oLHα IgG inhibited the proliferation of hCG-expressing human colorectal cancer cells (LS-174, HCT-116, HCT-15 and KM-12) in a dose-dependent manner. Furthermore, an intact anti-tumor vaccine was prepared by conjugating hCGß-oLHα with tetanus toxoid (TT) and this was used to immunize Balb/c mice bearing hCG-expressing SP2/0 tumor cells. The progression of tumors in these immunized mice was remarkably inhibited. These results suggest that hCGß-oLHα is a new promising immunogenic molecule for the development of an anti-hCG-based cancer vaccine.

Cytotoxicity of p-tyrosol and its derivatives may correlate with the inhibition of DNA replication initiation.

p-Tyrosol is a phenolic compound present in different dietary sources that can exert mild antioxidant properties based on in vitro and in vivo studies. In our study, two p-tyrosol derivatives (p-tyrosyl gallate and p-tyrosyl acetate) were synthesized and compared together with p-tyrosol and gallic acid for their cytotoxic activities on human cancer cells. p-Tyrosyl gallate had the most potent cytotoxicity and the major cytotoxic mechanism of its action was studied. We found that in HeLa cells, p-tyrosyl gallate can effectively induce cell cycle arrest during S phase and inhibited in vitro simian virus (SV40 DNA) replication. In addition, p-tyrosyl gallate can inhibit three important functional replication proteins (topoisomerase I, RPA and pol alpha-primase), especially pol alpha-primase. These results suggest that p-tyrosyl gallate-induced cell cycle arrest during S phase correlates with the inhibition of DNA replication. Pol alpha-primase may be the main target molecule. Taken together, we suggest that p-tyrosyl gallate is a strong anticancer drug candidate that warrants further investigation.

3-Chloro-2,5-dihydroxybenzyl alcohol activates human cervical carcinoma HeLa cell apoptosis by inducing DNA damage.

We have isolated 3-chloro-2,5-dihydroxybenzyl alcohol (CHBA) from marine-derived fungus Aspergillus sp. and characterized its apoptosis-inducing properties against human cervical carcinoma (HeLa) cells. Significantly decreased rates of proliferation and viability (IC50 approximately 35 microM) as well as evidence of apoptosis were observed with CHBA. Nuclear changes observed under fluorescence microscopy confirmed apoptosis occurrence and showed a typical pattern of chromatin condensation. Furthermore, results from Annexin V-FITC/PI dual staining indicated that CHBA induced earlier apoptosis of HeLa cells in a concentration- and time-dependent manner. CHBA also induced cytochrome c release from mitochondria into the cytosol and subsequent caspase activation involving caspase-9 and -3 by Western blotting assay was observed. We also found that CHBA was able to induce DNA damage and inhibit DNA replication followed by S phase arrest. The very sensitive alkaline microgel electrophoresis technique (comet assay) was used for estimation of the CHBA-induced DNA single strand breaks. These findings suggest that CHBA induces HeLa cell apoptosis by cytochrome c release and caspase activation pathway and that the effect of CHBA on apoptosis of HeLa cells is associated with DNA damage. Because of the ease of synthesis and structural manipulation, CHBA may have the potential to be developed into an anticancer agent.

Mechanism of cell cycle arrest by (8E,13Z,20Z)-strobilinin/(7E,13Z,20Z)-felixinin from a marine sponge Psammocinia sp.

Furanosesterterpenes, isolated from a marine sponge Psammocinia sp. have been reported to display significant cytotoxicity to some cancer cell lines. In this study, EZZ, an inseparable 1:1 mixture of (8E,3Z,20Z)-strobilinin and (7E,3Z,20Z)-felixinin, showed significant antiproliferative effect on human cervix carcinoma cell line (HeLa). Cell cycle analysis revealed that EZZ could arrest HeLa cells in S phase with a concomitant decrease in the cell population of G1 phase. By using simian virus (SV40) DNA in vitro replication system, we found that EZZ could inhibit DNA replication, which suggests that EZZ-induced S phase arrest might be the direct result of blocked DNA synthesis. Furthermore, low concentration of EZZ was found to be capable of significantly inhibiting the DNA cleavage by topoisomerase I (topo I) and reducing the polymerase alpha-primase (pol alpha-primase) activity, while the ssDNA binding activity of replication protein A (RPA) was less affected. Taken together, these results suggest that EZZ-induced cell cycle arrest in S phase correlate with the inhibition of DNA replication, and topo I and pol alpha-primase might be the two main target molecules.

Cytotoxicity of psammaplin A from a two-sponge association may correlate with the inhibition of DNA replication.

BACKGROUND: SV40 DNA replication system is a very useful tool to understand the mechanism of replication, which is a tightly regulated process. Many environmental and cellular factors can induce cell cycle arrest or apoptosis by inhibiting DNA replication. In the course of our search for bioactive metabolites from the marine sponges, psammaplin A was found to have some anticancer properties, the possible mechanism of which was studied. METHODS: Cell viability was determined by Cell Counting Kit-8 (CCK-8) to count living RAW264.7 cells by combining 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-8) and 1-methoxy-phenazine methosulfate (1-methoxy-PMS). The effect of psammaplin A on DNA replication was carried out in SV40 DNA replication system in vitro. The activities of topoisomerase I and polymerase alpha-primase were measured by the relaxation of superhelical plasmid DNA and the incorporation of [3H]dTTP to the template respectively. The ssDNA binding activity of RPA was assessed by Gel Mobility Shift Assay (GMSA). RESULTS: We have found that psammaplin A delivers significant cytotoxic activity against the RAW264.7 cell line. It was also found that psammaplin A could substantially inhibit SV40 DNA replication in vitro, in which polymerase alpha-primase is one of its main targets. CONCLUSION: Taken together, we suggest that psammaplin A-induced cytotoxicity may correlate with its inhibition on DNA replication. Psammaplin A has the potential to be developed as an anticancer drug.

Downregulation of SPARC expression inhibits the invasion of human trophoblast cells in vitro.

Successful pregnancy depends on the precise regulation of extravilloustrophoblast (EVT) invasion into the uterine decidua. SPARC (secreted protein acidic and rich in cysteine) is a matricellular glycoprotein that plays critical roles in the pathologies associated with obesity and diabetes, as well as tumorigenesis. The objective of this study was to investigate the role of SPARC in the process of trophoblast invasion which shares many similarities with tumor cell invasion. By Western blot, higher expression of SPARC was observed in mouse brain, ovary and uterus compared to other mouse tissues. Immunohistochemistry analysis revealed a spatio-temporal expression of SPARC in mouse uterus in the periimplantation period. At the implantation site of d8 pregnancy, SPARC mainly accumulated in the secondary decidua zone (SDZ), trophoblast cells and blastocyst. The expression of SPARC was also detected in human placental villi and trophoblast cell lines. In a Matrigel invasion assay, we found SPARC-specific RNA interference significantly reduced the invasion of human extravilloustrophoblast HTR8/SVneo cells. Microarray analysis revealed that SPARC depletion upregulated the expression of interleukin 11 (IL11), KISS1, insulin-like growth factor binding protein 4 (IGFBP4), collagen type I alpha 1 (COLIA1), matrix metallopeptidase 9 (MMP9), and downregulated the expression of the alpha polypeptide of chorionic gonadotropin (CGA), MMP1, gap junction protein alpha 1 (GJA1), et al. The gene array result was further validated by qRT-PCR and Western blot. The present data indicate that SPARC may play an important role in the regulation of normal placentation by promoting the invasion of trophoblast cells into the uterine decidua.

Serine protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF) inhibits the rat embryo implantation in vivo and interferes with cell adhesion in vitro.

BACKGROUND: This study was conducted to observe the in vivo effect of 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF) on embryo implantation in rats and its in vitro effect on cell adhesion. STUDY DESIGN: The anti-implantation efficacy of AEBSF in rats was determined by counting the number of visible implanted embryos on day 8 of pregnancy following intrauterine (5 mg and 10 mg AEBSF per horn) or tail vein (10 mg AEBSF per rat) administration on day 3 of pregnancy. The effects of AEBSF on cell adhesion were detected, respectively, by using the mouse blastocysts-endometrial cells or the human umbilical vein endothelial cells (HUVECs)-HeLa cells co-culture model. The alteration in protein secretion pattern of HUVECs and HeLa cells was detected by the proteome analysis. RESULTS: 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride showed an in vivo inhibitory effect on embryo implantation in rat. In vitro, AEBSF could disturb the growth of blastocysts on endometrial cells and inhibit the adhesion of HeLa cells on HUVECs. The treatment of AEBSF could alter the protein secretion pattern of co-cultured HUVEC-HeLa cells. CONCLUSION: 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride might be a potential leading compound for novel contraceptives, and its inhibitory effect on implantation might result from the interference in extracellular matrix remodeling process.