This study was aimed at developing an in vitro fluorescent substrate assay for the activity of leucyl aminopeptid-ase(LAP)from Echinococcus multilocularis and comparing it with the chemical chromogenic substrate enzyme activity assay.Through the establishment of reaction conditions for the fluorescent substrate-based in vitro enzyme activity assay,we com-pared the differences between the fluorescent substrate L-Leucine-7-amido-4-methylocoumarin(Leu-AMC)and the chemical chromogenic substrate L-Leucine-4-nitroanilide(Leu-pNA)through molecular docking,inhibition rates,and precision measures.Molecular docking revealed that the fluorescent substrate Leu-AMC had higher affinity for the protein than the chemical chromogenic substrate Leu-pNA.Through analysis of the effects of varying reaction conditions on fluorescence intensi-ty,we optimized the fluorescent substrate enzyme activity assay to demonstrate favorable performance at a reaction temperature of 37℃,a pH of 9.0,a protein concentration of 800 nmol/L,and a reaction duration of 60 minutes.Leu-AMC exhibited significant and distinct responses at a 5 μmol/L substrate concentration,under varying substrate conditions.The fluo-rescent substrate assay demonstrated more significant intergroup differences than the chemical chromogenic substrate assay when various inhibitors were added.This study established a fluorescence-based enzyme activity assay for leucyl aminopeptidase from Echinococcus multilocularis by using Leu-AMC as the substrate;this method demonstrated a more significant intergroup difference and sensitivity than the chemical chromogenic substrate assay.

Objective:To compare the dose-response effects of single-fraction ultra-high dose rate (FLASH) and conventional dose rate (CONV) whole abdominal irradiation (WAI) with X-rays on acute radiation-induced intestinal injury in mice, in order to identify optimal dose parameters and potential mechanisms.Methods:A total of 186 male C57BL/6J mice were randomly assigned to a non-irradiation group ( n=6), FLASH irradiation groups ( n=90), and CONV irradiation groups ( n=90). Acute radiation-induced intestinal injury models were established using single-fraction WAI with 11, 12, 13, 14, and 15 Gy X-rays (200 Gy/s for FLASH and 4 Gy/min for CONV). Changes in body weight, stool characteristics, and disease activity index (DAI) scores were assessed at 9 d post-irradiation. At 7 d post-irradiation at 11, 12, and 13 Gy, the intestines were collected for macroscopic examination and length measurement. The small intestine was selected for HE staining and quantitative analysis of intestinal crypt number and mucosal epithelial thickness. The survival of mice was assessed at 15 d post-WAI across all dose groups. Results:After single-fraction WAI at 11, 12, and 13 Gy, the body weight was higher in the FLASH group than that in the CONV group ( t=10.17, 12.65, 10.16, P<0.05). The DAI scores for the FLASH group were 1.00±1.10, 3.17±0.75, and 2.83±1.17, respectively, which were lower than those of the CONV group (4.33±0.52, 7.00±0.00, 8.60±0.55; t=8.70, 11.71, 14.99, P<0.05). However, after WAI at 14 Gy and 15 Gy, there were no significant differences in body weight and DAI between the FLASH group and the CONV group ( P>0.05). At 7 d after single-fraction WAI at 11, 12, and 13 Gy, mice in the FLASH group exhibited less intestinal congestion, edema, and shortening compared with the CONV group. The difference between the FLASH and CONV groups were statistically significant in small intestine length at 11 and 13 Gy ( t=4.42, 3.78, P<0.05), and in colorectal length at 11 and 12 Gy ( t=3.97, 3.12, P<0.05). Small intestine HE staining revealed superior preservation of intestinal architecture in the FLASH group compared with the CONV group, characterized by longer villi, increased crypt numbers, thicker mucosal epithelium, and enhanced structural integrity. The differences in crypt number and mucosal epithelial thickness were statistically significant ( tcrypt=13.10, 23.80, 11.90; tmucosal=5.75, 2.64, 7.74; P<0.05). At 15 d post-irradiation, the survival rate in the 15 Gy FLASH group was higher than that in the CONV group (50% vs. 10%, χ2=5.39, P<0.05), with a median survival extension of 6 d ( HR=0.340, 95% CI: 0.115 4-0.999 9). No significant survival differences were observed between the FLASH group and the CONV group at 11, 12, 13, and 14 Gy ( P>0.05). Conclusions:FLASH irradiation significantly alleviated acute radiation-induced intestinal injury from medium single-fraction WAI with 11, 12, and 13 Gy X-rays compared with CONV irradiation, and showed potential to improve mouse survival after single-fraction WAI at 15 Gy. This effect is likely associated with the preservation of intestinal crypts and exhibits a dose-dependent relationship.

Objective:The purpose of this study was to analyze the influencing factors of readmission after percutaneous coronary intervention(PCI)in patients with coronary heart disease and type 2 diabetes(T2DM),and to build a nomogram model.Methods:A retrospective study was conducted on 260 patients with coronary heart disease and T2DM who received PCI treatment in Yancheng Third People's Hospital from May 2019 to May 2023,clinical data were collected and followed up for 1 year.They were divided into on readmission group and unreadmission group based on their readmission after 1 year.Multivariate logistic regression analysis was conducted to determine risk factors,and a nomogram model was constructed using R software to evaluate its predictive efficiency.Results:Among the 260 patients,65 were readmitted after surgery,with a readmission rate of 25.00％(65/260).Univariate analysis showed that,left ventricular ejection fraction(LVEF),age,left main artery disease,hypertension history,number of coronary artery lesions,dyslipidemia,glycosylated hemoglobin(HbA1c),course of diabetes,fasting blood glucose(FBG),number of stents,and regular postoperative medication were related to readmission 1 year after PCI(P＜0.05).Age ≥ 70 years,hypertension history,coronary artery multi vessel disease,course of diabetes ≥ 10 years,HbA1c ≥7％,left main artery disease,dyslipidemia,LVEF＜50％,number of stents ≥3 were risk factor for readmission 1 year after PCI(P＜0.05).The nomogram model constructed based on the above risk factors has a C-index of 0.835 and an area under the receiver operating characteristic(ROC)the area under the curve(AUC)of 0.826.Conclusion:This study identified multiple risk factors for readmission in patients with coronary heart disease and T2DM 1 year after PCI.The constructed nomogram model can provide an effective tool for predicting the risk of readmission in clinical practice,and help medical staff develop personalized intervention measures to improve patient prognosis.

Extensive epigenetic reprogramming involves in memory CD8+ T-cell differentiation. The elaborate epigenetic rewiring underlying the heterogeneous functional states of CD8+ T cells remains hidden. Here, we profile single-cell chromatin accessibility and map enhancer-promoter interactomes to characterize the differentiation trajectory of memory CD8+ T cells. We reveal that under distinct epigenetic regulations, the early activated CD8+ T cells divergently originated for short-lived effector and memory precursor effector cells. We also uncover a defined epigenetic rewiring leading to the conversion from effector memory to central memory cells during memory formation. Additionally, we illustrate chromatin regulatory mechanisms underlying long-lasting versus transient transcription regulation during memory differentiation. Finally, we confirm the essential roles of Sox4 and Nrf2 in developing memory precursor effector and effector memory cells, respectively, and validate cell state-specific enhancers in regulating Il7r using CRISPR-Cas9. Our data pave the way for understanding the mechanism underlying epigenetic memory formation in CD8+ T-cell differentiation.
CD8-Positive T-Lymphocytes/metabolism* ; Cell Differentiation ; Chromatin/immunology* ; Animals ; Mice ; Immunologic Memory ; Epigenesis, Genetic ; SOXC Transcription Factors/immunology* ; NF-E2-Related Factor 2/immunology* ; Mice, Inbred C57BL ; Gene Regulatory Networks ; Enhancer Elements, Genetic

Metabolic-associated fatty liver disease (MAFLD) and osteoporosis (OP) are two very common metabolic diseases. A growing body of experimental evidence supports a pathophysiological link between MAFLD and OP. MAFLD is often associated with the development of OP. Rutaecarpine (RUT) is one of the main active components of Chinese medicine Euodiae Fructus. Our previous studies have demonstrated that RUT has lipid-lowering, anti-inflammatory and anti-atherosclerotic effects, and can improve the OP of rats. However, whether RUT can improve both fatty liver and OP symptoms of MAFLD mice at the same time remains to be investigated. In this study, we used C57BL/6 mice fed a high-fat diet (HFD) for 4 months to construct a MAFLD model, and gave the mice a low dose (5 mg·kg^-1) and a high dose (15 mg·kg^-1) of RUT by gavage for 4 weeks. The effects of RUT on liver steatosis and bone metabolism were then evaluated at the end of the experiment [this experiment was approved by the Experimental Animal Ethics Committee of Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences (approval number: IMB-20190124D₃03)]. The results showed that RUT treatment significantly reduced hepatic steatosis and lipid accumulation, and significantly reduced bone loss and promoted bone formation. In summary, this study shows that RUT has an effect of improving fatty liver and OP in MAFLD mice.

OBJECTIVE To analyze the quantity transfer rule in the processing of Astragalus membranaceus before and after moistening-soaking and steaming-soaking followed by cutting. METHODS Three batches of A. membranaceus decoction pieces processed through moistening-soaking and steaming-soaking followed by cutting were prepared. The HPLC overlapping fingerprints of A. membranaceus and its decoction pieces were established through the Similarity Evaluation System of Chromatographic Fingerprints of TCM （2012 edition）. Combined with the previous qualitative analysis results， the common peaks were identified， the changes of common peak area were analyzed， and the principal component analysis was carried out. The contents of calycosin-7-glucoside， astragaloside Ⅰ and astragaloside Ⅳ in A. membranaceus and its decoction pieces were determined by HPLC， and the content differences of each component in different samples were compared. RESULTS The results of fingerprint analysis showed that 17 common peaks were identified. After steaming-soaking and moistening-soaking of A. membranaceus， the proportion of common peak area in the decoction pieces changed compared with the original medicine （for example， in A. membranaceus steaming-soaking decoction pieces， the proportion of peak area of malonyl calycosin-7-glucoside and malonyl astragaloside Ⅰ decreased， while the proportion of peak area of calycosin-7-glucoside increased）. The results of principal component analysis showed that A. membranaceus， and its decoction pieces after moistening-soaking and steaming-soaking followed by cutting were all clustered into one category respectively. The results of content determination showed that， compared with A. membranaceus， the average content of calycosin-7-glucoside in A. membranaceus moistening-soaking decoction pieces was significantly reduced （P＜0.05）； the average contents of calycosin-7-glucoside and astragaloside Ⅳ in A. membranaceus steaming- soaking decoction pieces were significantly increased （P＜0.05）； there was no significant difference in the average content of astragaloside Ⅳ in A. membranaceus moistening-soaking decoction pieces and astragaloside Ⅰ in the two decoction pieces （P＞ 0.05）. CONCLUSIONS There are differences in the quantity transfer rules of A. membranaceus before and after moistening-soaking and steaming-soaking followed by cutting. Steaming-soaking followed by cutting may make the transformation of unstable components （such as malonyl calycosin-7-glucoside and malonyl astragaloside Ⅰ） more complete.

This article takes as its starting point the gradual postponement of the statutory retirement age outlined in the"State Council's Measures on Gradually Delaying the Legal Retirement Age,"issued on September 13,2024.An actuarial model is constructed to evaluate the effect of this policy on the sustainability of the employees'medical insurance pooling fund and associated fiscal responsibility.Based on these findings,relevant policy recommendations are proposed.The results indicate that,in the absence of a retirement delay policy,the employees'medical insurance pooling fund will be depleted by 2043,with total fiscal responsibility amounting to CNY 17 261.38 billion over the projection period.If all individuals retire in accordance with the stipulated policy,the depletion of the fund is delayed by four years,and overall fiscal responsibility decreases by 46.97%.Further analysis incorporating flexible retirement choices reveals that variations in individual willingness to delay retirement have relatively minor effects on both fund sustainability and fiscal responsibility compared to full compliance with the policy.Conclusion:While the implementation of the gradual retirement age extension policy contributes to enhancing the sustainability of the employees'medical insurance pooling fund and alleviating fiscal responsibility,long-term financial viability remains at risk.

Objective:To compare the dose-response effects of single-fraction ultra-high dose rate (FLASH) and conventional dose rate (CONV) whole abdominal irradiation (WAI) with X-rays on acute radiation-induced intestinal injury in mice, in order to identify optimal dose parameters and potential mechanisms.Methods:A total of 186 male C57BL/6J mice were randomly assigned to a non-irradiation group ( n=6), FLASH irradiation groups ( n=90), and CONV irradiation groups ( n=90). Acute radiation-induced intestinal injury models were established using single-fraction WAI with 11, 12, 13, 14, and 15 Gy X-rays (200 Gy/s for FLASH and 4 Gy/min for CONV). Changes in body weight, stool characteristics, and disease activity index (DAI) scores were assessed at 9 d post-irradiation. At 7 d post-irradiation at 11, 12, and 13 Gy, the intestines were collected for macroscopic examination and length measurement. The small intestine was selected for HE staining and quantitative analysis of intestinal crypt number and mucosal epithelial thickness. The survival of mice was assessed at 15 d post-WAI across all dose groups. Results:After single-fraction WAI at 11, 12, and 13 Gy, the body weight was higher in the FLASH group than that in the CONV group ( t=10.17, 12.65, 10.16, P<0.05). The DAI scores for the FLASH group were 1.00±1.10, 3.17±0.75, and 2.83±1.17, respectively, which were lower than those of the CONV group (4.33±0.52, 7.00±0.00, 8.60±0.55; t=8.70, 11.71, 14.99, P<0.05). However, after WAI at 14 Gy and 15 Gy, there were no significant differences in body weight and DAI between the FLASH group and the CONV group ( P>0.05). At 7 d after single-fraction WAI at 11, 12, and 13 Gy, mice in the FLASH group exhibited less intestinal congestion, edema, and shortening compared with the CONV group. The difference between the FLASH and CONV groups were statistically significant in small intestine length at 11 and 13 Gy ( t=4.42, 3.78, P<0.05), and in colorectal length at 11 and 12 Gy ( t=3.97, 3.12, P<0.05). Small intestine HE staining revealed superior preservation of intestinal architecture in the FLASH group compared with the CONV group, characterized by longer villi, increased crypt numbers, thicker mucosal epithelium, and enhanced structural integrity. The differences in crypt number and mucosal epithelial thickness were statistically significant ( tcrypt=13.10, 23.80, 11.90; tmucosal=5.75, 2.64, 7.74; P<0.05). At 15 d post-irradiation, the survival rate in the 15 Gy FLASH group was higher than that in the CONV group (50% vs. 10%, χ2=5.39, P<0.05), with a median survival extension of 6 d ( HR=0.340, 95% CI: 0.115 4-0.999 9). No significant survival differences were observed between the FLASH group and the CONV group at 11, 12, 13, and 14 Gy ( P>0.05). Conclusions:FLASH irradiation significantly alleviated acute radiation-induced intestinal injury from medium single-fraction WAI with 11, 12, and 13 Gy X-rays compared with CONV irradiation, and showed potential to improve mouse survival after single-fraction WAI at 15 Gy. This effect is likely associated with the preservation of intestinal crypts and exhibits a dose-dependent relationship.

AKT,also known as Protein Kinase B(PKB),plays a critical role in cell proliferation and metabolism.There are three isoforms of AKT:AKT1,AKT2,and AKT3.The effects of these isoforms on the pluripotency and differentiation of mouse embryonic stem cells(mESCs)remain unclear.This study aims to explore the impact of three AKT isoform-specific knockouts on the self-renewal and differen-tiation of mouse embryonic stem cells.Using CRISPR/Cas9 gene-editing technology,AKT isoform-spe-cific knockout cell lines were established.The phenotypic and molecular changes were analyzed through Western blotting,flow cytometry,qRT-PCR,CCK-8 assays,Alkaline Phosphatase(AP)staining,and RNA-seq.The construction of AKT isoform-specific knockout cell lines was successful.The loss of AKT1 and AKT2 inhibited the proliferation of mESCs.The knockout of any single AKT isoform did not affect the expression of pluripotency genes at both mRNA or protein levels.However,during embryoid body forma-tion,the deletion of any of the three AKT isoforms affected the mRNA expression levels of genes in all three germ layers.Transcriptome analysis showed that compared to wild-type mESCs,995,547,and 429 differentially expressed genes(|log2FC|≧1,P＜0.05)were identified inAKT1,AKT2,and AKT3 isoform-specific knockout cells,respectively.There was some overlap in the differentially expressed genes regulated by these three isoforms.In conclusion,the independent knockout of AKT isoforms does not af-fect the maintenance of pluripotency in mouse embryonic stem cells,but they are crucial for differentia-tion.The three AKT isoforms can collectively regulate gene expression while retaining their own regulato-ry specificity.This study provides a foundation for understanding the unique and overlapping roles of AKT isoforms in stem cell biology,highlighting their importance in maintaining stem cell function and differen-tiation.

AKT,also known as Protein Kinase B(PKB),plays a critical role in cell proliferation and metabolism.There are three isoforms of AKT:AKT1,AKT2,and AKT3.The effects of these isoforms on the pluripotency and differentiation of mouse embryonic stem cells(mESCs)remain unclear.This study aims to explore the impact of three AKT isoform-specific knockouts on the self-renewal and differen-tiation of mouse embryonic stem cells.Using CRISPR/Cas9 gene-editing technology,AKT isoform-spe-cific knockout cell lines were established.The phenotypic and molecular changes were analyzed through Western blotting,flow cytometry,qRT-PCR,CCK-8 assays,Alkaline Phosphatase(AP)staining,and RNA-seq.The construction of AKT isoform-specific knockout cell lines was successful.The loss of AKT1 and AKT2 inhibited the proliferation of mESCs.The knockout of any single AKT isoform did not affect the expression of pluripotency genes at both mRNA or protein levels.However,during embryoid body forma-tion,the deletion of any of the three AKT isoforms affected the mRNA expression levels of genes in all three germ layers.Transcriptome analysis showed that compared to wild-type mESCs,995,547,and 429 differentially expressed genes(|log2FC|≧1,P＜0.05)were identified inAKT1,AKT2,and AKT3 isoform-specific knockout cells,respectively.There was some overlap in the differentially expressed genes regulated by these three isoforms.In conclusion,the independent knockout of AKT isoforms does not af-fect the maintenance of pluripotency in mouse embryonic stem cells,but they are crucial for differentia-tion.The three AKT isoforms can collectively regulate gene expression while retaining their own regulato-ry specificity.This study provides a foundation for understanding the unique and overlapping roles of AKT isoforms in stem cell biology,highlighting their importance in maintaining stem cell function and differen-tiation.