To explore the effects of long-term treatment of different dietary energy levels on ovarian expression of mRNAs for LHR and FSHR,the present study was performed in nine growth-matched littermate crossbred (Land-race×Large White X Duroc) prepubertal gilts. At approximately 30 kg of body weight and 50 day of age,gilts were housed with individual feeding stalls and placed on a normal level of feeding for 90 days (dl-90) with free ac-cess to water and food throughout the whole research. From d91 ,littermates were divided and randomly assigned to one of the following three treatment lines for 3 weeks till d112:Group H,Group M, and Group L, fed the high energy level diet (n = 3, digestible energy 14.87 MJ/kg), moderate energy level diet (n = 3, digestible energy 12.39 MJ/ kg), and low energy level diet (n = 3, digestible energy 9.98 MJ/kg), respectively. When gilts were slaughtered on d112 after 3 weeks energy treatment, both ovaries of every gilts were collected,snap frozen in liquid nitrogen and re-tained at -80℃ for use to determine and analysis the relative amount of ovarian LHR and FSHR mRNAs using semi-quantitative RT-PCR. Results showed that the effect of dietary energy treatment was notable: the ovarian ex-pression of mRNAs for LHR and FSHR was significantly higher (P<0.05) in gilts treated with high energy diet compared to gilts treated with moderate and low energy diets, while gilts treated with low energy diet had a signifi-cantly lower (P<0.05) ovarian LHR and FSHR expression compared with gilts treated with moderate and high en-ergy diets. These results revealed that ovarian expression of I.HR and FSHR in prepubertal gilts increased as the lev-el of dietary energy intake elevated,i, e. , high energy diet can markedly enhance ovarian expression of mRNAs for LHR and FSHR,whereas energy deficit markedly suppress the expression.

Food toxicology plays a crucial role in supporting scientific and technical aspects of food safety risk assessment.However,traditional methods relying on animal testing are becoming increas-ingly inadequate for identifying and evaluating emerging foods and unknown risks.There is a strong push worldwide towards the development of new approach methodologies(NAMs)based on non-animal testing methods.Policies and regulations related to NAMs are being standardized gradually in the European Union,the United States,and China.Some progress has also been made in applying these methodologies in food toxicology research in China.For instance,within the"Food Toxicology Program"at the National Center for Food Safety Risk Assessment,high-content and high-throughput in vitro hazard identification models employing model organisms like human macrophages,hepatocytes,adipocytes,embryonic stem cells,and zebrafish,as well as Toxicological Thresholds of Concern and quantitative in vitro to in vivo extrapolation based on physiologically-based toxicokinetic models have been estab-lished and applied.Nonetheless,new toxicological hazard identification technologies still face challenges such as inadequate elucidation of toxic mechanisms,insufficient collaborative research efforts,and inef-ficient translation of these findings into practical applications.

The senescence of bone marrow mesenchymal stem cells (BM-MSCs) will induce age-related bone tissue degeneration and chronic inflammation, and reduce its application effect for cell therapy. More and more active ingredients of traditional chinese medicine have been proved to intervene BM - MSCs senescence, playing an important role in bone diseases prevention and treatment, and improving the therapeutic effect of BM-MSCs. In this paper, the latest research progress on the molecular mechanism of traditional chinese medicine active ingredients interfering BM-MSCs senescence was summarized, in order to provide new direction and reference basis for senescence intervention research and clinical application improvement of BM-MSCs.