[Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats].

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

[Exploration of mechanism of "simultaneous treatment of brain and heart" of Naoxintong Capsules based on Toll-like receptor signaling pathway].

This study aims to explore the mechanism of "simultaneous treatment of the brain and the heart" of Naoxintong Capsules(NXT) under cerebral ischemia based on Toll-like receptor(TLR) signaling pathway.Male SD rats were randomized into sham operation group, model group, NXT group, and positive drug group.Middle cerebral artery occlusion(MCAO) model rats were used in model group, NXT group, and positive drug group, respectively.Neurological function was scored with the Bederson scale, and brain infarct rate was measured by 2,3,5-triphenyltetrazolium chloride(TTC) staining.Brain edema was detected with wet-dry weight method.Hematoxylin-eosin(HE) staining and TdT-mediated dUTP nick-end labeling(TUNEL) staining were used to observe and count apoptotic cardiocytes.In addition, serum myocardial enzymes were measured.The expression of 8 TLR signaling pathway-related proteins interferon-α(IFN-α), interferon regulatory factor-3(IRF3), interferon regulatory factor-7(IRF7), TLR2, TLR4, TLR7, TLR9, and tumor necrosis factor-α(TNF-α) in the cerebral cortex and heart of rats was detected by Western blot. Brain infarct rate, neurological function score, and brain water content in NXT group decreased significantly compared with those in the model group. At the same time, the reduction in apoptosis rate of cardiocytes and the content of serum aspartate aminotransferase(AST), alanine aminotransferase(ALT), creatine kinase(CK), and lactate dehydrogenase(LDH) were decreased in the NXT group.Systems pharmacological results and previous research showed that TLR signaling pathway played an important role in immune inflammatory response.The study of TLR signaling pathway and related proteins is helpful to elucidate the mechanism of "simultaneous treatment of the brain and the heart". Western blot results showed that NXT significantly inhibited the expression of IRF3, IRF7, TLR2, TLR7, and TNF-α in cerebral cortex and heart under cerebral ischemia.Cerebral ischemia influences cardiac functions, and TLR signaling pathway is one of the pathways for "simultaneous treatment of the brain and the heart" of NXT.

Effects of mitochondria-associated Ca2+ transporters suppression on oocyte activation.

Oocyte activation deficiency leads to female infertility. [Ca2+ ]i oscillations are required for mitochondrial energy supplement transition from the resting to the excited state, but the underlying mechanisms are still very little known. Three mitochondrial Ca2+ channels, Mitochondria Calcium Uniporter (MCU), Na+ /Ca2+ Exchanger (NCLX) and Voltage-dependent Ca2+ Channel (VDAC), were deactivated by inhibitors RU360, CGP37157 and Erastin, respectively. Both Erastin and CGP37157 inhibited mitochondrial activity significantly while attenuating [Ca2+ ]i and [Ca2+ ]m oscillations, which caused developmental block of pronuclear formation. Thus, NCLX and VDAC are two mitochondria-associated Ca2+ transporter proteins regulating oocyte activation, which may be used as potential targets to treat female infertility. SIGNIFICANCE OF THE STUDY: NCLX and VDAC are two mitochondria-associated Ca2+ transporter proteins regulating oocyte activation.

Glucocorticoid exposure affects female fertility by exerting its effect on the uterus but not on the oocyte: lessons from a hypercortisolism mouse model.

STUDY QUESTION: What is the impact of glucocorticoid (GC) on female reproduction? SUMMARY ANSWER: Corticosterone (CORT) exposure causes little damage to oocyte quality or developmental competence but has an adverse effect on the uterus, which causes decreased implantation, embryo death and subsequent infertility. WHAT IS KNOWN ALREADY: Chronic treatment with high GC doses is effective in controlling most allergic diseases but may lead to metabolic disorders such as obesity that are closely related with reproductive function. STUDY DESIGN, SIZE, DURATION: Hypercortisolism was induced in a female mouse model by supplementing the drinking water with 100 µg/ml of CORT. Controls received vehicle (1% v/v ethanol) only. After 4 weeks treatment mice were either mated or killed in estrus for hormone and organ measurements. In the first experiment, treatment with CORT or control continued during pregnancy but in the second CORT treatment was stopped after mating. To identify the effects of GC exposure on the uterus, blastocysts were generated by IVF of oocytes from CORT and control mice and replaced into recipients receiving the opposite treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: The effects of hypercortisolism on female mice were first characterized by living body fat content, body weight, food intake, hormone and biochemical measurements, a glucose tolerance test and an insulin resistance test. Fertility was determined with or without CORT-treatment during pregnancy. Oocyte quality was assessed by oocyte maturation, mitochondrial distribution, reactive oxygen species production, mitochondrial DNA mutations and morphology of blastocysts produced in vivo or in vitro. Blastocyst cross-transfer was done to evaluate the causes of embryonic development failure. Fetus development and uterus morphology evaluation as well as culture of oocytes in vitro with gradient concentrations of CORT were also carried out. MAIN RESULTS AND THE ROLE OF CHANCE: In the hypercortisolism female mouse model, body weight and food intake were much higher than in the control, and corticosterone, estradiol, cholesterol (CHO) and triglycerides (TG) in the plasma of CORT-treated mice was significantly increased. The hypercortisolism female mice were infertile when CORT-treatment was sustained during pregnancy but fertile if CORT-treatment was stopped after mating. The rate of successful implantation in hypercortisolism mice with sustained CORT-treatment during pregnancy was significantly lower than in the control, and the implanted embryos could not develop beyond 13.5 dpc. Blastocyst cross-transfer showed that blastocysts from CORT-treated mice could develop to term in the uterus of control mice, but blastocysts from control mice failed to develop to term when they were transferred into CORT-treated mice, providing evidence that the infertility was mainly caused by an altered uterine environment. CORT administration did not affect oocyte maturation, mitochondrial distribution, ROS production and blastocyst morphology, but increased mitochondrial DNA mutations. Culture of oocytes in vitro with gradient concentrations of CORT showed that only very high concentrations of CORT caused damage to oocyte developmental competence. LARGE SCALE DATA: NA. LIMITATIONS, REASONS FOR CAUTION: The mouse model has the advantages of a consistent genetic and physiological background and openness to experimental manipulation over clinical studies but may not represent the human situation. WIDER IMPLICATIONS OF THE FINDINGS: Our findings show that special care should be taken when administering CORT during pregnancy, and provide important information concerning female reproduction when treating patients by subjecting them to chronic GC exposure. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Key R&D Program of China (Nos. 2016YFA0100400 and 2017YFC1000600) and the National Natural Science Foundation of China (31472055). The authors have no conflicts of interest.