Changes in DNA integrity and gene expression in ovarian follicular cells of lipopolysaccharide-treated female mice.

BACKGROUND: Lipopolysaccharide (LPS), the endotoxin of gram-negative bacteria, can impair female reproductive function. However, there is a little information about genotoxic stress in ovarian follicular cells as well as about the changes in oocyte developmental potential under endotoxemia. So the aim of our study was to investigate in vitro oocyte maturation, the DNA damage and expression of some developmental competence-related genes in follicular cells of mice treated with LPS. METHODS: LPS (3mg/kg) was intraperitoneally injected into the mice for 24h, and in vitro maturation of mouse oocyte was determined. The expression levels of genes in cumulus cells were detected by reverse transcriptase polymerase chain reaction. DNA damage in granulosa cells was assessed by the alkaline comet assay. RESULTS: LPS injection caused an impairment of oocyte maturation in vitro: the percentage of oocytes reaching metaphase I and metaphase II decreased markedly compared to vehicle control mice. At the same time we observed strong DNA damage in granulosa cells of LPS-treated animals. The endotoxemia resulted in significantly reduced mRNA expression levels for hyaluronan synthase 2 (HAS2), cyclooxygenase 2 (COX2) and Gremlin-1 (GREM1) genes compared with control. CONCLUSIONS: Our results obtained in a mouse model of endotoxin-induced female reproductive dysfunction suggest that LPS may affect oocyte quality through the induction of DNA damage and decreasing the cumulus expression of genes associated with cumulus expansion and oocyte maturation, such as HAS2, COX2 and GREM1.

Hepatocytes response to interferon alpha levels recorded after liver resection.

Extensive damage of liver parenchyma stimulates hepatic cells to transit from quiescence to proliferation with eventual restoration of liver mass and function. Our recent studies have revealed upregulated expression of interferon (IFN)-α and its antiviral activity during the early hours after partial hepatectomy. In this study, we analyzed the response of primary hepatocytes from intact liver to IFN-α mimicking its levels (250 U/mL) during the transition period of liver restoration. The gene expression profile was analyzed with rat genome array 230 2.0 (Affymetrix). After 3- and 6-h treatment we identified respectively 28 and 124 differentially expressed genes responsible for autonomous changes in hepatocytes and those involving non-parenchymal cells in a concerted response to IFN-α. The response has an energy sparing character and affects all levels of gene expression. The factors activating T cells and apoptosis are opposed by those restricting the signal propagation, inhibiting T cells activation, and promoting survival. The partial resemblance between the specific in vitro response to IFN-α and the processes in regenerating liver is discussed. Our study opens the way to a more focused investigation of the liver cell response to quasiphysiological dose of IFN-α.

Poly(ADP-ribose) polymerase inhibitor, 3-aminobenzamide, protects against experimental immune ovarian failure in mice.

The activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) may play an important role in numerous pathological conditions. The aim of the present study was to clarify the role of PARP in the pathogenesis of immune ovarian failure in mice and to examine the possible protective action of PARP inhibitor, 3-aminobenzamide (3-ABA). An experimental ovarian injury induced in mice by immunization with allogenic ovarian extract impaired the meiotic maturation of oocytes and increased apoptosis and necrosis of follicular cells and cells isolated from the spleen, lymph nodes and thymus. The immunization affected blood leukogram indicating the presence of an inflammatory response. Treatment with 3-ABA (1 h before antigen administrations, 0.02 mg/g intraperitoneally, twice a week during the three-week experiment) was effective to prevent meiotic maturation impairment, cell death and inflammation. The decrease in the necrosis of follicular and immune cells after 3-ABA treatment was more pronounced than that in apoptosis. It is concluded that PARP may contribute to immune-mediated ovary injury and PARP inhibitor, 3-ABA, protects against experimental immune ovarian failure, partially via a decrease in necrotic cell death.

Melatonin protects against experimental immune ovarian failure in mice.

Experimental immune ovarian failure induced in CBA mice by either administration of xenogenic anti-ovarian antibodies or immunization with allogenic ovarian extracts impaired the meiotic maturation of oocytes and increased apoptosis of follicular cells. Immunization was accompanied with the inflammation and active immune reaction, as shown by the enlargement of regional lymph nodes, the increase of apoptosis in cultured lymph node cells and the increase of band and segmented neutrophil percentage in the blood. Triple injections of melatonin (5 mg/kg of the body weight) an hour before antibodies administration restored the meiotic maturation of oocytes and supported the survival of follicular and lymph node cells. In contrast, melatonin application upon immunization was not effective to prevent the ovary impairment and cell death. It is concluded that melatonin protects against immune ovary failure induced by xenogenic anti-ovarian antibodies.