Erythrocytes counteract the negative effects of female ageing on mouse preimplantation embryo development and blastocyst formation.

BACKGROUND: The low developmental competence of embryos from ageing females remains an enigma; it is presumably attributable to oxidative stress. A number of antioxidant mechanisms exist in the erythrocyte and these have been investigated in other cells and tissues. However, very few studies have reported the effects of erythrocyte supplementation on developmental competence in ageing embryos. METHODS: In Experiment 1, IVF embryos from young (7-10 weeks) mice were cultured in medium supplemented with an oxidizing agent, hypoxanthine/xanthine oxidase, in the presence and absence of erythrocytes. In Experiment 2, the development of embryos derived from young and ageing (40-50 weeks) female mice was assessed in the presence and absence of erythrocytes. RESULTS: In Experiment 1, the presence of hypoxanthine/xanthine oxidase significantly inhibited embryo development (P < 0.0001). Erythrocyte supplementation clearly overcame the detrimental effects in a dose-related manner. In Experiment 2, in the absence of erythrocytes, developmental competence was significantly lower in embryos from ageing females than in those from young females (P < 0.01). However, in ageing females, the supplementation of erythrocytes significantly promoted the development of embryos to the blastocyst stage (51.1% versus 77.3%; P < 0.01). CONCLUSIONS: Supplementation with erythrocytes can counteract the negative effect of maternal ageing on embryo development and blastocyst formation.

Retinoic acid-inducible gene-I is induced by interferon-gamma and regulates CXCL11 expression in HeLa cells.

Retinoic acid-inducible gene-I (RIG-I) is a member of the DExH box family proteins, which have diverse roles in the regulation of gene expression and cellular functions. RIG-I is one of the factors regulated by interferon (IFN)-gamma and regarded as an intracellular signaling molecule for IFN-gamma. IFN-gamma is a major cytokine and also suggested to be involved in embryonal implantation and pregnancy. It is demonstrated that IFN-gamma stimulates endometrial epithelial cells to produce CXCL11, which is implicated in implantation. The aim of the present study was to investigate the effect of IFN-gamma on RIG-I expression in HeLa cells, a cell line derived from human uterine carcinoma. We found that RIG-I mRNA and protein were expressed in HeLa cells stimulated with IFN-gamma. The effect of IFN-gamma was observed in concentration- and time-dependent manners. The RNA interference against RIG-I resulted in the suppression of the IFN-gamma-induced CXCL11 expression. Immunohistochemical studies revealed the RIG-I expression in the normal human endometrium, suggesting a possible role of RIG-I in human reproductive organs.

Retinoic acid-inducible gene-I mediates RANTES/CCL5 expression in U373MG human astrocytoma cells stimulated with double-stranded RNA.

Retinoic acid-inducible gene-I (RIG-I) mediates part of the cell signaling in response to viral infection. Polyinosinic-polycytidilic acid (poly IC) is a synthetic double-stranded RNA (dsRNA) and mimics viral infection when applied to cell cultures. The CC chemokine, RANTES (regulated on activation, normal T-cell expressed and secreted), is a potent attractant for inflammatory cells such as memory T-lymphocytes, monocytes and eosinophils. In the present study, we demonstrated that poly IC enhances the expression of RIG-I in U373MG human astrocytoma cells. The RNA interference of RIG-I resulted in the suppression of the poly IC-induced RANTES expression. Pretreatment of the cells with SB203580, an inhibitor of p38 mitogen-activated protein kinase, and dexamethasone inhibited the poly IC-induced expression of RIG-I. Furthermore, poly IC upregulated RIG-I in normal human astrocytes in culture and the in vivo injection of poly IC into the striatum of the mouse brain induced the expression of RIG-I in astrocytes. We conclude that RIG-I may be involved in immune reactions against viral infection, at least in part, through the regulation of RANTES expression in astrocytes.