ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease （AD） through regulating mitochondrial Ca²⁺ homeostasis and kinetic balance based on the protein kinase A （PKA）/calcineurin （CaN） signaling pathway. MethodsSixty three-month-old amyloid precursor protein （APP）/presenilin 1 （PS1） double transgenic mice were randomly divided into a model group， a donepezil group（0.65 mg·kg^-1）， a low-dose Yizhi Qingxin prescription group （YQF-L，2.6 g·kg^-1）， a medium-dose Yizhi Qingxin prescription group （YQF-M，5.2 g·kg^-1）， and a high-dose Yizhi Qingxin prescription group （YQF-H，10.4 g·kg^-1）， with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily， with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition （NOR） and Morris water maze （MWM） tests. Hematoxylin-eosin （HE）/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy （TEM） was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester （Fluo-4 AM） Ca²⁺ probe was used to measure intracellular Ca²⁺ concentration in brain tissue. Western blot was used to determine the protein expression of PKA， CaN， sodium/calcium/lithium exchanger （NCLX）， mitochondrial calcium uniporter （MCU）， calmodulin （CaM）， dynamin-related protein 1 （Drp1）， and phosphorylated dynamin-related protein 1 （serine 637 site） ［p-Drp1（S637）］ in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the expression of PKA， CaN， CaM， NCLX， MCU， and Drp1 mRNAs. ResultsCompared with those in the normal group， the recognition index （RI） of the model group decreased （P0.01）， and the number of crossings through the original platform area， the duration of stay in the target quadrant， and the distance were reduced （P0.01）. The protein expression of PKA， NCLX， and p-DRP1 （ser637） significantly decreased （P0.05）， and the mRNA expression of PKA and NCLX significantly decreased （P0.05）. The escape latency （EL） was prolonged （P0.05）， and the intracellular Ca²⁺ level significantly increased （P0.01）. The protein expression of CaN， CaM， MCU， and Drp1， as well as the mRNA expression of CaN， MCU， and Drp1， significantly increased （P0.05）. After intervention with Donepezil and Yizhi Qingxin prescription， compared with that in the model group， the RI of the treatment group significantly increased （P0.05）， and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased （P0.05）. The protein expression of PKA， NCLX， and p-Drp1 （ser637） and the mRNA expression of PKA and NCLX significantly increased （P0.05）. On the 4th and 5th days， the EL was shortened （P0.05）， and the intracellular Ca²⁺ level decreased （P0.05）. The protein expression of CaN， CaM， MCU， and Drp1 and the mRNA expression of CaN， MCU， and Drp1 significantly decreased （P0.05）. ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway， upregulates the expression of PKA， NCLX， and p-Drp1 （ser637） proteins， reduces the expression of CaN， CaM， MCU， and Drp1 proteins， and regulates Ca²⁺ homeostasis and mitochondrial dynamic balance， thereby enhancing the spatial learning and memory abilities of AD mice.

ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease （AD） through regulating mitochondrial Ca²⁺ homeostasis and kinetic balance based on the protein kinase A （PKA）/calcineurin （CaN） signaling pathway. MethodsSixty three-month-old amyloid precursor protein （APP）/presenilin 1 （PS1） double transgenic mice were randomly divided into a model group， a donepezil group（0.65 mg·kg^-1）， a low-dose Yizhi Qingxin prescription group （YQF-L，2.6 g·kg^-1）， a medium-dose Yizhi Qingxin prescription group （YQF-M，5.2 g·kg^-1）， and a high-dose Yizhi Qingxin prescription group （YQF-H，10.4 g·kg^-1）， with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily， with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition （NOR） and Morris water maze （MWM） tests. Hematoxylin-eosin （HE）/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy （TEM） was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester （Fluo-4 AM） Ca²⁺ probe was used to measure intracellular Ca²⁺ concentration in brain tissue. Western blot was used to determine the protein expression of PKA， CaN， sodium/calcium/lithium exchanger （NCLX）， mitochondrial calcium uniporter （MCU）， calmodulin （CaM）， dynamin-related protein 1 （Drp1）， and phosphorylated dynamin-related protein 1 （serine 637 site） ［p-Drp1（S637）］ in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the expression of PKA， CaN， CaM， NCLX， MCU， and Drp1 mRNAs. ResultsCompared with those in the normal group， the recognition index （RI） of the model group decreased （P0.01）， and the number of crossings through the original platform area， the duration of stay in the target quadrant， and the distance were reduced （P0.01）. The protein expression of PKA， NCLX， and p-DRP1 （ser637） significantly decreased （P0.05）， and the mRNA expression of PKA and NCLX significantly decreased （P0.05）. The escape latency （EL） was prolonged （P0.05）， and the intracellular Ca²⁺ level significantly increased （P0.01）. The protein expression of CaN， CaM， MCU， and Drp1， as well as the mRNA expression of CaN， MCU， and Drp1， significantly increased （P0.05）. After intervention with Donepezil and Yizhi Qingxin prescription， compared with that in the model group， the RI of the treatment group significantly increased （P0.05）， and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased （P0.05）. The protein expression of PKA， NCLX， and p-Drp1 （ser637） and the mRNA expression of PKA and NCLX significantly increased （P0.05）. On the 4th and 5th days， the EL was shortened （P0.05）， and the intracellular Ca²⁺ level decreased （P0.05）. The protein expression of CaN， CaM， MCU， and Drp1 and the mRNA expression of CaN， MCU， and Drp1 significantly decreased （P0.05）. ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway， upregulates the expression of PKA， NCLX， and p-Drp1 （ser637） proteins， reduces the expression of CaN， CaM， MCU， and Drp1 proteins， and regulates Ca²⁺ homeostasis and mitochondrial dynamic balance， thereby enhancing the spatial learning and memory abilities of AD mice.

The ribosomal protein S11(RPS11)from Enterococcus faecalis is was heterologously ex-pressed using the Pichia pastoris system.The RPS11 gene sequence was optimized to match the yeast codon preference,and the recombinant expression vector pPIC9K-RPS11 was constructed.Electroporation was used to transform the vector into the Pichia pastoris GS115 strain,and high-copy recombinant strains were selected through G418 resistance screening.Protein expression was induced with methanol,and the expression was verified by SDS-PAGE.The recombinant protein was applied in a mouse melanoma treatment model to evaluate its therapeutic effects.The results showed that the recombinant expression vector pPIC9K-RPS11 successfully expressed the target protein with an approximate molecular weight of 14 kDa in Pichia pastoris.The optimal fermenta-tion conditions were determined to be an induction temperature of 30 ℃,induction time of 72 h,and methanol concentration of 1％.Analysis using a mouse peritoneal macrophage trained immuni-ty model revealed that recombinant RPS11 possessed biological activity capable of inducing trained immunity.Additionally,therapeutic experiments in a mouse melanoma model demonstrated that recombinant RPS11 significantly inhibited tumor growth.These findings suggest that the recombi-nant RPS11 secreted by Pichia pastoris not only possesses biological activity in inducing trained immunity but also inhibits tumor cell growth in a mouse melanoma model,providing theoretical support for the heterologous expression and potential applications of recombinant RPS11.

Objective:To analyze the application effects of case-based learning (CBL) + Seminar teaching method based on Toulmin model in the education and teaching of clinical medicine innovation class.Methods:A total of 60 students from the clinical medicine innovation class at The Second Affiliated Hospital of Guangzhou Medical University from September 2021 to September 2023 were selected as research objects. These students were divided into control group ( n=30) and research group ( n=30) according to different teaching programs. The traditional teaching method was adopted in the control group, and the CBL + Seminar teaching method based on Toulmin model was adopted in the research group. The two groups were compared in terms of clinical knowledge, clinical skill, and clinical case analysis scores; changes in clinical thinking ability after teaching; and satisfaction with the teaching process. SPSS 22.0 was used for t-test and chi-square test. Results:The research group significantly outperformed the control group in clinical knowledge [(89.59±3.46) points vs. (83.23±3.02) points], clinical skill [(88.87±3.23) points vs. (83.62±3.13) points], and clinical case analysis [(89.73±3.51) points vs. (82.62±3.19) points] ( t=7.58, 6.39, 8.21, P<0.001). The clinical thinking ability after teaching was significantly higher in the research group compared to the control group [(258.49±13.36) points vs. (242.56±13.02) points] ( t=4.67, P<0.001). The overall satisfaction rate of teaching was significantly higher in the research group compared to the control group (100.00% vs. 80.00%, χ2=4.63, P=0.031). Conclusions:The CBL + Seminar teaching method based on Toulmin model can effectively improve student learning performance and clinical thinking ability, demonstrating a promising application value in the education and teaching of clinical medicine innovation class.

The ribosomal protein S11(RPS11)from Enterococcus faecalis is was heterologously ex-pressed using the Pichia pastoris system.The RPS11 gene sequence was optimized to match the yeast codon preference,and the recombinant expression vector pPIC9K-RPS11 was constructed.Electroporation was used to transform the vector into the Pichia pastoris GS115 strain,and high-copy recombinant strains were selected through G418 resistance screening.Protein expression was induced with methanol,and the expression was verified by SDS-PAGE.The recombinant protein was applied in a mouse melanoma treatment model to evaluate its therapeutic effects.The results showed that the recombinant expression vector pPIC9K-RPS11 successfully expressed the target protein with an approximate molecular weight of 14 kDa in Pichia pastoris.The optimal fermenta-tion conditions were determined to be an induction temperature of 30 ℃,induction time of 72 h,and methanol concentration of 1％.Analysis using a mouse peritoneal macrophage trained immuni-ty model revealed that recombinant RPS11 possessed biological activity capable of inducing trained immunity.Additionally,therapeutic experiments in a mouse melanoma model demonstrated that recombinant RPS11 significantly inhibited tumor growth.These findings suggest that the recombi-nant RPS11 secreted by Pichia pastoris not only possesses biological activity in inducing trained immunity but also inhibits tumor cell growth in a mouse melanoma model,providing theoretical support for the heterologous expression and potential applications of recombinant RPS11.

ObjectiveTo investigate the mechanism of danshenol A （DA） pretreatment in alleviating myocardial ischemia-reperfusion injury （MIRI） by regulating cardiomyocyte ferroptosis by in vivo and in vitro experiments. MethodsA MIRI model was established in SD rats， and an in vitro oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed with H9C2 cells. Both models were treated with DA. H9C2 cells were allocated into blank， model （OGD/R）， DA， ferroptosis inducer （erastin）， and ferroptosis inhibitor （Fer-1） groups. Cell viability was assessed by the methyl thiazolyl tetrazolium （MTT） assay. Biochemical assays were performed to measure the superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione （GSH）， and ferrous ion （Fe²⁺） levels. Dihydroethidium （DHE） fluorescence assay was adopted to quantify the reactive oxygen species （ROS） level. Real-time PCR and Western blot were employed to quantify the mRNA and protein levels， respectively， of prostaglandin-endoperoxide synthase 2 （PTGS2）， glutathione peroxidase 4 （GPX4）， ferritin heavy chain 1 （FTH1）， and acyl-coA synthetase long-chain family 4 （ACSL4）. Sixty SPF-grade healthy male SD rats were randomly assigned to control， model （MIRI）， DA， erastin， and Fer-1 groups. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure the serum levels of cardiac troponin I （cTnI）， lactate dehydrogenase （LDH）， and creatine kinase （CK）. Histopathological changes in the myocardial tissue were observed by hematoxylin-eosin （HE） staining. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL）. The effect of DA on cardiomyocyte ferroptosis were observed and analyzed by in vivo and in vitro experiments. ResultsIn vitro experiment： compared with the blank group， the OGD/R model group showed reduced cell viability， elevated levels of ROS， MDA， and Fe²⁺， up-regulated mRNA and protein levels of ACSL4， lowered levels of SOD and GSH， and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05，P<0.01）. The DA and Fer-1 groups exhibited consistent trends： cell viability， SOD and GSH levels， and the mRNA and protein levels of PTGS2， GPX4， and FTH1 were significantly restored， while the ROS， MDA， and Fe²⁺ levels， and the mRNA and protein levels of ACSL4 were reduced （P<0.05，P<0.01）. In vivo experiment： Compared with the control group， the MIRI model group showed elevated serum levels of cTnI， LDH， and CK， increased cardiomyocyte apoptosis rate， risen levels of ROS， MDA， and Fe²⁺， and up-regulated mRNA and protein levels of ACSL4. However， both DA and Fer-1 groups exhibited reductions in the indicators above （P<0.05）. Compared with the control group， the MIRI model group demonstrated reduced levels of SOD and GSH and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05）. In contrast， both DA and Fer-1 upregulated these indicators （P<0.05）， effectively reversing the trends in the model group. In addition， the MIRI model group showed swelling of cardiomyocytes， disarrangement of cardiac muscle fibers， and massive inflammatory cell infiltration， which were alleviated in the DA and Fer-1 groups. ConclusionDA alleviates MIRI by inhibiting ferroptosis and inflammation， demonstrating therapeutic potential in acute myocardial infarction.

ObjectiveTo investigate the mechanism of danshenol A （DA） pretreatment in alleviating myocardial ischemia-reperfusion injury （MIRI） by regulating cardiomyocyte ferroptosis by in vivo and in vitro experiments. MethodsA MIRI model was established in SD rats， and an in vitro oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed with H9C2 cells. Both models were treated with DA. H9C2 cells were allocated into blank， model （OGD/R）， DA， ferroptosis inducer （erastin）， and ferroptosis inhibitor （Fer-1） groups. Cell viability was assessed by the methyl thiazolyl tetrazolium （MTT） assay. Biochemical assays were performed to measure the superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione （GSH）， and ferrous ion （Fe²⁺） levels. Dihydroethidium （DHE） fluorescence assay was adopted to quantify the reactive oxygen species （ROS） level. Real-time PCR and Western blot were employed to quantify the mRNA and protein levels， respectively， of prostaglandin-endoperoxide synthase 2 （PTGS2）， glutathione peroxidase 4 （GPX4）， ferritin heavy chain 1 （FTH1）， and acyl-coA synthetase long-chain family 4 （ACSL4）. Sixty SPF-grade healthy male SD rats were randomly assigned to control， model （MIRI）， DA， erastin， and Fer-1 groups. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure the serum levels of cardiac troponin I （cTnI）， lactate dehydrogenase （LDH）， and creatine kinase （CK）. Histopathological changes in the myocardial tissue were observed by hematoxylin-eosin （HE） staining. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL）. The effect of DA on cardiomyocyte ferroptosis were observed and analyzed by in vivo and in vitro experiments. ResultsIn vitro experiment： compared with the blank group， the OGD/R model group showed reduced cell viability， elevated levels of ROS， MDA， and Fe²⁺， up-regulated mRNA and protein levels of ACSL4， lowered levels of SOD and GSH， and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05，P<0.01）. The DA and Fer-1 groups exhibited consistent trends： cell viability， SOD and GSH levels， and the mRNA and protein levels of PTGS2， GPX4， and FTH1 were significantly restored， while the ROS， MDA， and Fe²⁺ levels， and the mRNA and protein levels of ACSL4 were reduced （P<0.05，P<0.01）. In vivo experiment： Compared with the control group， the MIRI model group showed elevated serum levels of cTnI， LDH， and CK， increased cardiomyocyte apoptosis rate， risen levels of ROS， MDA， and Fe²⁺， and up-regulated mRNA and protein levels of ACSL4. However， both DA and Fer-1 groups exhibited reductions in the indicators above （P<0.05）. Compared with the control group， the MIRI model group demonstrated reduced levels of SOD and GSH and down-regulated mRNA and protein levels of PTGS2， GPX4， and FTH1 （P<0.05）. In contrast， both DA and Fer-1 upregulated these indicators （P<0.05）， effectively reversing the trends in the model group. In addition， the MIRI model group showed swelling of cardiomyocytes， disarrangement of cardiac muscle fibers， and massive inflammatory cell infiltration， which were alleviated in the DA and Fer-1 groups. ConclusionDA alleviates MIRI by inhibiting ferroptosis and inflammation， demonstrating therapeutic potential in acute myocardial infarction.

Objective:To analyze the application effects of case-based learning (CBL) + Seminar teaching method based on Toulmin model in the education and teaching of clinical medicine innovation class.Methods:A total of 60 students from the clinical medicine innovation class at The Second Affiliated Hospital of Guangzhou Medical University from September 2021 to September 2023 were selected as research objects. These students were divided into control group ( n=30) and research group ( n=30) according to different teaching programs. The traditional teaching method was adopted in the control group, and the CBL + Seminar teaching method based on Toulmin model was adopted in the research group. The two groups were compared in terms of clinical knowledge, clinical skill, and clinical case analysis scores; changes in clinical thinking ability after teaching; and satisfaction with the teaching process. SPSS 22.0 was used for t-test and chi-square test. Results:The research group significantly outperformed the control group in clinical knowledge [(89.59±3.46) points vs. (83.23±3.02) points], clinical skill [(88.87±3.23) points vs. (83.62±3.13) points], and clinical case analysis [(89.73±3.51) points vs. (82.62±3.19) points] ( t=7.58, 6.39, 8.21, P<0.001). The clinical thinking ability after teaching was significantly higher in the research group compared to the control group [(258.49±13.36) points vs. (242.56±13.02) points] ( t=4.67, P<0.001). The overall satisfaction rate of teaching was significantly higher in the research group compared to the control group (100.00% vs. 80.00%, χ2=4.63, P=0.031). Conclusions:The CBL + Seminar teaching method based on Toulmin model can effectively improve student learning performance and clinical thinking ability, demonstrating a promising application value in the education and teaching of clinical medicine innovation class.

Iron metabolism is a critical factor in tumorigenesis and development. Although TP53 mutations are prevalent in glioblastoma (GBM), the mechanisms by which TP53 regulates iron metabolism remain elusive. We reveal an imbalance iron homeostasis in GBM via TCGA database analysis. TP53 mutations disrupted iron homeostasis in GBM, characterized by elevated total iron levels and reduced ferritin (FTH). The gain-of-function effect triggered by TP53 mutations upregulates itchy E3 ubiquitin-protein ligase (ITCH) protein expression in astrocytes, leading to FTH degradation and an increase in free iron levels. TP53-mut astrocytes were more tolerant to the high iron environment induced by exogenous ferric ammonium citrate (FAC), but the increase in intracellular free iron made them more sensitive to Erastin-induced ferroptosis. Interestingly, we found that Erastin combined with FAC treatment significantly increased ferroptosis. These findings provide new insights for drug development and therapeutic modalities for GBM patients with TP53 mutations from iron metabolism perspectives.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Glioblastoma/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; Homeostasis/physiology* ; Ferritins/metabolism* ; Brain Neoplasms/genetics* ; Mutation ; Astrocytes/drug effects* ; Cell Line, Tumor ; Piperazines/pharmacology* ; Quaternary Ammonium Compounds/pharmacology* ; Ferric Compounds

Addressing the challenge of traditional physical/semi physical simulation methods being difficult to achieve full process and full element simulation of extravehicular activities,virtual reality technology is utilized to break through the limitations of physical environments and establish a virtual reality simulation system for extravehicular activities.Based on the application characteristics of space station extravehicular activity engineering,with the goal of improving system practicality and usability,integrating the visual immersion of virtual images,the ontology of real operation,and the consistency of virtual and real space perception,a three-dimensional scene simulation,multi-mode joystick interaction paradigm,continuous operation actions simulation of extravehicular operations,and interactive operation virtual/real space consistency method that were proposed and designed for the realistic visual perception and extravehicular operation.The system has been successfully applied to astronaut training,program validation,joint exercise,and flight control support for sixteen extravehicular activities from SZ-12 to SZ-18.The results showed that the complete reproduction of the static/dynamic realistic comprehensive scene was achieved on the ground for the human-machine operation in the entire process of extravehicular activity,and the system is an essential and important means of ground simulation for extravehicular activity.