From the practice of application of PBL teaching in biochemistry,we find that the PBL has obvious advantages in inability training,class course and knowledge application,but the PBL should be applied in limited theory-learning course.

Background: in vitro culture of preantral follicles is a promising technology for fertility preservation. Objectives: This study aims to investigate an optimized three-dimensional (3D) fetal bovine serum (FBS)-free preantral follicle culture system having a simple and easy operation. Methods: The isolated follicles from mouse ovaries were randomly divided in an ultra-low attachment 96-well plates supplement with FBS or bovine serum albumin (BSA) culture or encapsulated with an alginate supplement with FBS or BSA culture. Meanwhile, estradiol (E 2 ) concentration was assessed through enzyme-linked immunosorbent assay of culture supernatants. The diameter of follicular growth was measured, and the lumen of the follicle was photographed. Spindle microtubules of oocytes were detected via immunofluorescence.The ability of oocytes to fertilize was assessed using in vitro fertilization. Results: The diameters were larger for the growing secondary follicles cultured in ultra-low attachment 96-well plates than in the alginate gel on days 6, 8, and 10 (p < 0.05). Meanwhile, the E 2 concentration in the BSA-supplemented medium was significantly higher in the alginate gel than in the other three groups on days 6 and 8 (p < 0.05), and the oocytes in the FBS-free system could complete meiosis and fertilization in vitro. Conclusions The present study furnishes insights into the mature oocytes obtained from the 3D culture of the preantral follicle by using ultra-low attachment 96-well plate with an FBSfree system in vitro and supports the clinical practices to achieve competent, mature oocytes for in vitro fertilization.

Microplastics(MPs)and nanoplastics(NPs)have become hazardous materials due to the massive amount of plastic waste and disposable masks,but their specific health effects remain uncertain.In this study,fluorescence-labeled polystyrene NPs(PS-NPs)were injected into the circulatory systems of mice to determine the distribution and potential toxic effects of NPs in vivo.Interestingly,whole-body imaging found that PS-NPs accumulated in the testes of mice.Therefore,the toxic effects of PS-NPs on the reproduction systems and the spermatocytes cell line of male mice,and their mechanisms,were investigated.After oral exposure to PS-NPs,their spermatogenesis was affected and the spermatogenic cells were damaged.The spermatocyte cell line GC-2 was exposed to PS-NPs and analyzed using RNA sequencing(RNA-seq)to determine the toxic mechanisms;a ferroptosis pathway was found after PS-NP exposure.The phenomena and indicators of ferroptosis were then determined and verified by ferroptosis inhibitor ferrostatin-1(Fer-1),and it was also found that nuclear factor erythroid 2-related factor 2(Nrf2)played an important role in spermatogenic cell ferroptosis induced by PS-NPs.Finally,it was confirmed in vivo that this mechanism of Nrf2 played a protective role in PS-NPs-induced male reproductive toxicity.This study demonstrated that PS-NPs induce male reproductive dysfunction in mice by causing spermatogenic cell ferroptosis dependent on Nrf2.

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Breast cancer is one of the most malignant tumors and is associated with high mortality rates among women. Lycium barbarum polysaccharide (LBP) is an extract from the fruits of the traditional Chinese herb, L. barbarum. LBP is a promising anticancer drug, due to its high activity and low toxicity. Although it has anticancer properties, its mechanisms of action have not been fully established. Ferroptosis, which is a novel anticancer strategy, is a cell death mechanism that relies on iron-dependent lipid reactive oxygen species (ROS) accumulation. In this study, human breast cancer cells (Michigan Cancer Foundation-7 (MCF-7) and MD Anderson-Metastatic Breast-231 (MDA-MB-231)) were treated with LBP. LBP inhibited their viability and proliferation in association with high levels of ferroptosis. Therefore, we aimed to ascertain whether LBP reduced cell viability through ferroptosis. We found that the structure and function of mitochondria, lipid peroxidation, and expression of solute carrier family 7 member 11 (SLC7A11, also known as xCT, the light-chain subunit of cystine/glutamate antiporter system X_c^-) and glutathione peroxidase 4 (GPX4) were altered by LBP. Moreover, the ferroptosis inhibitor, Ferrostatin-1 (Fer-1), rescued LBP-induced ferroptosis-associated events including reduced cell viability and glutathione (GSH) production, accumulation of intracellular free divalent iron ions and malondialdehyde (MDA), and down-regulation of the expression of xCT and GPX4. Erastin (xCT inhibitor) and RSL3 (GPX4 inhibitor) inhibited the expression of xCT and GPX4, respectively, which was lower after the co-treatment of LBP with Erastin and RSL3. These results suggest that LBP effectively prevents breast cancer cell proliferation and promotes ferroptosis via the xCT/GPX4 pathway. Therefore, LBP exhibits novel anticancer properties by triggering ferroptosis, and may be a potential therapeutic option for breast cancer.
Breast Neoplasms/drug therapy* ; Drugs, Chinese Herbal/pharmacology* ; Female ; Ferroptosis ; Glutathione/metabolism* ; Humans ; Iron/metabolism*