[Naringenin promotes osteogenic differentiation of BMSCs via SDF-1α/CXCR4 signaling axis].

PURPOSE: To explore the influence of naringenin on osteogenic differentiation of bone mesenchymal stem cells(BMSCs), and the role of SDF-1α/CXCR4 signaling axis in the osteogenic differentiation by naringenin. METHODS: BMSCs of the rats were isolated,cultured and tested. CCK-8 assay was used to explore the proliferation ability of BMSCs in different concentrations of naringenin, and alkaline phosphatase(ALP) activity was detected. RT-qPCR was used to detect the mRNA expression of ALP, OCN, CXCR4 and SDF-1α in different groups. The expressions of CXCR4 and SDF-1α protein in BMSCs during osteogenic differentiation in different experimental groups were detected by ELISA. SPSS 21.0 software package was used for statistical analysis of the data. RESULTS: The results of cell identification showed that the cultured cells were BMSCs. At 1 d and 3 d, all concentrations of naringenin had no significant effect on the proliferation of BMSCs; and at 5 d, 50 µg/mL of naringenin promoted proliferation of BMSCs；furthermore, at 7 d, all concentrations of naringenin promoted proliferation of BMSCs(P＜0.05). ALP activity value gradually increased in each concentration over time. From the RT-qPCR experiment, the mRNA expression of ALP, OCN, CXCR4 and SDF-1α in the naringenin group and the osteogenic induction group was significantly increased compared with the medium group(P＜0.05). ELISA assay showed that the protein expressions of CXCR4 and SDF-1α increased gradually in the four groups as time went on and the expression of two proteins was the highest in 100 µg/mL naringenin group. CONCLUSIONS: Naringenin can promote the proliferation and osteogenic differentiation of BMSCs. SDF-1α/CXCR4 signaling axis is involved in the osteogenic differentiation of BMSCs by naringenin,particularly in the early stage of BMSCs osteogenic differentiation.

Mitochondrial translocation of estrogen receptor ß affords resistance to oxidative insult-induced apoptosis and contributes to the pathogenesis of endometriosis.

Endometriosis is the major cause of female infertility and has been linked to the action of estrogen and estrogen receptor (ER). A new pool of ERß locates within mitochondria, which regulates the endometriotic cell withstanding external insults, but its effect remains controversial. We hypothesize that mitochondrial estrogen receptor ERß (mtERß) is a pivotal regulator in estradiol-mediated cell protection leading to the endometriotic progression. We observed elevated levels of ERß in the endometriotic tissues. A dramatic increase of ERß in mitochondria (mtERß) was found in the ectopic endometriotic tissues, or the estradiol-primed primary endometriotic cells. We analyzed the mtERß-specific overexpressing clone (mtsERß), which exhibited higher mitochondrial bioenergetics and lower reactive oxygen species (ROS) generation. The mtsERß-overexpressed endometriotic cells displayed an enhanced migration phenotype, whereas significantly attenuated migration by mitochondrial respiratory inhibitor (oligomycin) or ERß deficiency by shERß. Further investigations revealed that ERß directly modulated mitochondrial DNA (mtDNA) gene expression by interacting with mtDNA D-loop and polymerase γ. The mtsERß afforded a resistance to oxidative insult-induced apoptosis through the induction of the ROS scavenger enzyme Mn-superoxide dismutase and anti-apoptotic protein Bcl-2. Collectively, the demonstration of mtERß responses in restoration of mitochondrial bioenergetics and inhibition of mitochondria-dependent apoptotic events provides insight into the pathogenesis of endometriosis, suggesting ERß-selective estrogen receptor modulator may serve as novel therapeutics of endometriosis in the future.

Estrogen receptor-ß in mitochondria: implications for mitochondrial bioenergetics and tumorigenesis.

Estrogen enhances mitochondrial function by enhancing mitochondrial biogenesis and sustaining mitochondrial energy-transducing capacity. Shifts in mitochondrial bioenergetic pathways from oxidative phosphorylation to glycolysis have been hypothesized to be involved in estrogen-induced tumorigenesis. Studies have shown that mitochondria are an important target of estrogen. Estrogen receptor-ß (ERß) has been shown to localize to mitochondria in a ligand-dependent or -independent manner and can affect mitochondrial bioenergetics and anti-apoptotic signaling. However, the functional role of mitochondrial ERß in tumorigenesis remains unclear. Clinical studies of ERß-related tumorigenesis have shown that ERß stimulates mitochondrial metabolism to meet the high energy demands of processes such as cell proliferation, cell survival, and transformation. Thus, in elucidating the precise role of mitochondrial ERß in cell transformation and tumorigenesis, it will be particularly valuable to explore new approaches for the development of medical treatments targeting mitochondrial ERß-mediated mitochondrial function and preventing apoptosis.

[Comparison of aquatic predicted no-effect concentrations (PNECs) pentachlorophenol derived from different assessment approaches].

Predicted no-effect concentration (PNEC) is the key for ecological risk assessment and has become a focus of the study. Generally, extrapolation was used to derive PNEC values by different evaluation approaches according to results of single species toxicity test. However, PNEC values were different for the same toxicity data for the same chemicals if extrapolation methods were different. To evaluate PNEC values derived by different assessment methods, PNEC values of pentachlorophenol (PCP) were calculated using three different approaches, i. e. point estimation, statistical evaluation as well as interval evaluation. At the same time, the main factors controlling PNEC values were analyzed. The results showed that PNEC values for PCP by different assessment factors were 0.420 microg x L(-1) for acute toxicity data and 0.500 microg x L(-1) for chronic toxicity data, respectively. The PNEC values for PCP by statistical evaluation were 10.1 microg x L(-1) for probit unit and 8.10 microg x L(-1) for logit unit. The values derived by interval evaluation were 6.00 microg x L(-1) for PNEC-L95% and 11.8 microg x L(-1) for PNEC-L50%, respectively. PNECs obtained by the point estimation were the lowest and lower one order of magnitude than the PNEC values obtained by the other two methods. The PNEC values derived by the statistical assessment and interval evaluation were very similar. In addition, toxicity data type and statistical models have little effect on PNEC value for PCP with a great body of toxicity data. The results indicated that statistical evaluation and interval evaluation methods should be selected to derive PNEC values for well-studied substances like PCP, while point estimation should be used in preliminary screening assessment of chemicals to determine whether the effect is of concern.

Notch 1 signaling pathway effect on implantation competency.

OBJECTIVE: To investigate the relationship between the Notch 1 signaling pathway and the embryo implantation rate. DESIGN: Mouse embryos were cultured in vitro, and implantation competency was quantified. SETTING: Tertiary fertility center of a university teaching hospital. ANIMAL(S): Outbred ICR strain mouse embryos. INTERVENTION(S): The expression of Notch 1 was altered by adding a γ-secretase inhibitor to the culture medium. We quantified the consequent effect on embryo implantation. MAIN OUTCOME MEASURE(S): We measured the messenger RNA level of Notch 1 gene at different embryonic stages, embryo implantation rate under different culture conditions, the amount of Notch 1, and related implantation competency. RESULT(S): Quantitative polymerase chain reaction showed that the expression of Notch 1 increased during the implantation window. Adding γ-secretase inhibitor in the culture medium decreased the percentage of blastocysts in a dose-dependent manner. A Matrigel invasion assay showed that the competency of implantation required adequate expression of Notch 1 intracellular domain. CONCLUSION(S): Expression of Notch 1 at the proper time is required for the competency of embryo implantation; this effect is mediated through regulation of Notch 1 intracellular domain expression.