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.

Foodstuff contamination and pattern of consumption by population of foremost radioactively contaminated territories in Ukraine during the remote period of the Chornobyl disaster clean-up

Objective. The goal of the study was to estimate, from the perspective and in terms of hygienic provisions, the level of local food contamination by 137Cs and their pattern of consumption by residents of foremost radionuclide contaminated territories of Ukraine (Zhytomyr, Kyiv and Rivne oblasts) in the remote period of the Chornobyl disaster. Materials and methods. The article presents analytical data from the National Statistics Office of Ukraine concerning production and consumption of agricultural products in the territories of foremost severe radioactive contamination (TRC) i.e. Zhytomyr, Kyiv and Rivne oblasts (provinces). Data on levels of food contamination (milk, meat, fruits and vegetables, wild mushrooms and berries) received from the regional radiological control centers (RCC) and sanitary and epidemiological agencies/bureaus (SEA) were analyzed. According to results of questionnaire survey of residents in TRC of investigated regions (oblasts) the public awareness of radioactive contamination levels in local food production, their level of consumption and the use of cooking measures to reduce internal dose were assayed. Analytical, mathematical, statistical, sociological, and software engineering methods were applied. Results and conclusions. It was found that in the country and in study areas as well there is more than a half decrease of milk and meat production and consumption, and almost half times increased production of potato. It was shown that locally produced food and wide use of wild berries and mushrooms are dominated in the diet of TRC residents in the remote period after the Chornobyl disaster. Ecological and hygienic monitoring of foodstuffs in TRC proves the probability of product consumption with high content of radioactive materials. Residents territories of the foremost severe radioactive contamination in Zhytomyr, Kyiv and Rivne oblasts are aware about possible contamination of locally produced food with substances of Chornobyl origin and about the ways to reduce the contamination by means of cooking. In order to reduce the levels of possible internal exposure to radiation in population of TRC the agricultural amelioration and monitoring of radioactive contamination of wild and agricultural products should be continued.