1.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.
2.Temporal therapy utilizing exosomes derived from M2 macrophages demonstrates enhanced efficacy in alleviating neuropathic pain in diabetic rats
Wei WEI ; Jun FANG ; Baozhong YANG ; Chenlong CUI ; Jiacheng WEI ; Yating XUE
The Korean Journal of Pain 2025;38(1):14-28
Background:
Diabetic pain patients have increased pain at night. Exosomes can relieve neuropathic pain. This study aimed to investigate the efficacy of exosome administration at different time points in relieving diabetic neuropathic pain (DNP) in rats.
Methods:
M2 macrophages from bone marrow were induced in mice and exosomes were extracted. A diabetic rat model was induced using streptozotocin, with the mechanical withdrawal threshold (MWT) of the rats beingmeasured at ≤ 80% of the basal value after 14 days, indicating successful construction of the DNP rat model.Exosomes were administered on three consecutive days at ZT0 (zeitgeber time) and ZT12. Parameters including blood glucose levels, body weight, MWT, and thermal withdrawal latency (TWL) were assessed in the rats. The lumbar spinal cord of rats was examined on days 21 and 28 to measure inflammatory factors and observe the expression of M1 and M2 microglia. Furthermore, microglia were exposed to lipopolysaccharide (LPS) and LPS + exosomes in a controlled in vitro setting to assess alterations in microglia phenotype involving the NF-kB p65 andIKBα inflammatory signaling pathways.
Results:
The findings revealed that administration of exosomes during the rat resting period at ZT12 resulted in increased MWT and TWL, as well as a shift in microglia polarization towards the M2 phenotype. In vitro analysis indicated that exosomes influenced microglia polarization and suppressed the phosphorylation of NF-kB p65 andIKBα.
Conclusions
Temporal therapy with exosomes effectively reduces pain in DNP rats by polarizing microglia andaffecting NF-kB p65 and IKBα signaling pathways.
3.Research progress on occupational health of interventional radiation workers
Junfang MA ; Fang ZHANG ; Wei CUI
Chinese Journal of Radiological Health 2025;34(2):297-302
With the rapid development of interventional radiology technology, the occupational health risk of interventional radiation workers has attracted increasing attention. This paper reviews recent studies on hematological changes, DNA damage and molecular-level changes, cancer, eye lens, and other health impairments among interventional radiation workers. The aim is to provide an overview of the current research progress as well as a scientific basis for the implementation of targeted protective measures to improve the occupational health level of interventional radiology workers.
4.Neuroprotective effects and mechanisms of osteocalcin in an Alzheimer's disease cell model
Lilin FANG ; Qifeng ZHU ; Mingda ZHANG ; Man CUI ; Shijin LU ; Yu YAN
Journal of Army Medical University 2025;47(16):1883-1893
Objective To explore the neuroprotective effects of osteocalcin(OCN)on an Alzheimer's disease(AD)cell model and its potential mechanisms,providing a scientific basis for new therapeutic targets for AD.Methods Human neuroblastoma cell line SH-SY5Y was treated with 40 nmol/L okadaic acid(OA)for 24 h to establish an AD cell model.The cells were divided into a normal group(untreated SH-SY5Y cells),a model group(40 nmol/L OA intervention),and an OCN intervention group(intervention with various concentrations of OCN in the AD cell model),and AKT knockout/overexpression groups(AKT-KO group and AKT-OE group),and AKT-KO OCN group and AKT-OE OCN group.CCK-8 assay was used to detect the changes in cell viability.Wright's staining was employed to observe the morphological changes of AD cells.Western blotting was utilized to detect the protein levels of Tau,p-Tau,Bax,Bcl-2,Caspase-3 and their lytic types,as well as the expression of Tau,p-Tau,mTOR,AKT and p-AKT in each group after AKT knockout/overexpression.TUNEL staining and flow cytometry were applied to detect the changes in early and late apoptotic cells and the apoptotic rate in the OCN-treated AD cell model.Results ①Compared to the normal group,the model group exhibited a significant decrease in cell viability,noticeable morphological and structural damage,upregulation of p-Tau and Caspase-3,increased early and late apoptosis,and a significantly higher apoptotic rate(P<0.05).②After treatment of different concentrations of OCN for 24 h,cell viability was increased to varying degrees compared to the AD model group,with the 100 pg/mL OCN group showing a significant increase in cell viability(P<0.01)and marked improvement in cell number and morphology(P<0.01).③ Compared to the AD cell model group,the p-Tau/Tau ratio was decreased in all OCN treatment groups,particularly in the 100 pg/mL OCN intervention group,where the p-Tau/Tau ratio was significantly lower than that of the model group(P<0.01).④ Compared to the model group,a significant concentration-dependent decrease in the Cleaved Caspase-3/Caspase-3 ratio was observed when OCN concentrations ranged from 1 to 100 pg/mL,with a significant reduction in the Bax/Bcl-2 ratio in the 100 pg/mL group(P<0.000 1).⑤ The results of TUNEL staining and flow cytometry showed that,compared to the model group,all concentrations of OCN effectively inhibited the apoptosis in the AD model cells,with a significant reduction in early and late apoptotic cells and apoptotic rate in the 100 pg/mL OCN group.⑥ Compared with the control group and the model group,the P-AKT was significantly increased in the AKT-OE group after AKT overexpression(P<0.05).The expression level of AKT protein was decreased in the AKT-KO group after AKT knockout(P<0.05).When the AKT pathway was inhibited,the expression level of p-Tau was higher in the AKT-KO group than the control group(P<0.05),and when the AKT was overexpressed,the expression level was significantly inhibited(P<0.05).Conclusion OCN may inhibit cell apoptosis and reduce p-tau protein level by regulating the ratio of Caspase-3/Caspase-3 and Bax/Bcl-2,and thereby improve the morphology of AD model cells and effectively protect nerve cells,which may be related to the regulation of the AKT/mTOR pathway.
5.Systematic Optimization of Swelling-Enzymatic Extraction and Aqueous Two-Phase Purification for Phycocyanin
Jia-Rong LIN ; Shun-Yi WANG ; Fang LUO ; Cui-Ying LIN ; Zhen-Yu LIN
Chinese Journal of Analytical Chemistry 2025;53(9):1516-1525
An integrated extraction-purification process was established in this work for efficient phycocyanin production from dried Spirulina platensispowder.Initially,phycocyanin was extracted from algal biomass using a combined swelling-enzymatic lysis strategy.Single-factor experiments were carried out to systematically evaluate the effects of critical parameters,including system pH,enzymatic hydrolysis duration,and temperature,on phycocyanin extraction yield.Subsequently,a three-factor,three-level Box-Behnken response surface methodology design was employed to optimize the extraction process,with phycocyanin concentration and purity in the extract serving as response variables.A predictive regression model identified optimal conditions as follows:pH 6.4,hydrolysis time 3.2 h,and temperature 35.4℃.Experimental validation under these conditions yielded a phycocyanin recovery of 26.6%.Following extraction,purification was achieved via a polyethylene glycol-phosphate aqueous two-phase extraction system,which elevated the final purity to 4.21.Results demonstrated that the swelling-enzymatic lysis approach effectively disrupted algal cellular structures,significantly enhancing phycocyanin release efficiency.Concurrently,the aqueous two-phase system enabled selective partitioning and enrichment of the target protein under mild conditions.The integrated process exhibited high extraction efficiency,gentle purification,and robust operability,rendering it suitable for the scalable production of natural phycocyanin.This work provided both methodological foundations and technical support for advancing phycocyanin applications in natural pigments,biomedicine,and analytical detection.
6.Study on Uncertainty and Scalability in Single-Analysis Salivary Peptidome Studies
Xiu-Feng FANG ; Bing-Jia CUI ; Jin-Ling XU ; Yong WANG
Chinese Journal of Analytical Chemistry 2025;53(11):1820-1827,中插1-中插3
Nano liquid chromatography-high resolution tandem mass spectrometry(LC-HRMS/MS)is widely used for body fluid peptidome analysis,yet the impact of replicate analyses remains overlooked.Using salivary peptidome,in this work,10 replicate analyses of the same sample were conducted.It was found that although m/z and molecular weight ranges were consistent across replicates,single runs identified only 348-576 unique peptides from 32-39 degraded proteins.Merging all replicates revealed 1237 peptides from 77 proteins,a 2.5 folds increase in peptides and 2 folds increase in proteins.Instrument stability was confirmed via intensity/retention time of 12 peptides.Merged peptides primarily derived from high-abundance proteins(e.g.,Statherin,PRP1/2).Analysis of 20 peptides showed that the some peptides were detected in single analysis but confidence varying(19%-99%),low-confidence peptides(<95%)exceeded 95%after replicate.signal intensity alone didn't determine confidence and peptides spanning the sequence region between the longest and the shortest detected fragments could be identified.The above findings suggested that single-run LC-MS peptidomics analysis carried inherent false negatives and uncertainties.However,by integrating the results of a single analysis with the mechanism of enzymatic hydrolysis for endogenous peptides,it was possible to make reasonable inferences and extrapolations regarding peptides derived from highly abundant degraded proteins.
7.Progress in research on the role of DNA methylation in cervical cancer
International Journal of Laboratory Medicine 2025;46(20):2533-2539
Cervical cancer poses a significant threat to women's health worldwide,and its early detection is crucial for improving treatment outcomes and reducing mortality rates.DNA methylation,as a stable epigenet-ic marker,plays a significant role in the occurrence and development of cervical cancer.The combination of methylation markers with traditional screening methods has been shown to achieve high sensitivity and speci-ficity.This article provides a concise review of the potential,challenges,and future developments of DNA methylation in cervical cancer screening,as well as how these molecular markers can facilitate more precise risk stratification and personalized management of cervical cancer.
8.Research progress on NCOA4-mediated ferritinophagy and related diseases.
Chen JIA ; Hong-Ji LIN ; Fang CUI ; Rui LU ; Yi-Ting ZHANG ; Zhi-Qin PENG ; Min SHI
Acta Physiologica Sinica 2025;77(1):194-208
Nuclear receptor co-activator 4 (NCOA4) acts as a selective cargo receptor that binds to ferritin, a cytoplasmic iron storage complex. By mediating ferritinophagy, NCOA4 regulates iron metabolism and releases free iron in the body, thus playing a crucial role in a variety of biological processes, including growth, development, and metabolism. Recent studies have shown that NCOA4-mediated ferritinophagy is closely associated with the occurrence and development of iron metabolism-related diseases, such as liver fibrosis, renal cell carcinoma, and neurodegenerative diseases. In addition, a number of clinical drugs have been identified to modulate NCOA4-mediated ferritinophagy, significantly affecting disease progression and treatment efficacy. This paper aims to review the current research progress on the role of NCOA4-mediated ferritinophagy in related diseases, in order to provide new ideas for targeted clinical therapy.
Humans
;
Nuclear Receptor Coactivators/physiology*
;
Ferritins/metabolism*
;
Animals
;
Neurodegenerative Diseases/metabolism*
;
Iron/metabolism*
;
Autophagy/physiology*
;
Liver Cirrhosis/metabolism*
;
Carcinoma, Renal Cell/metabolism*
;
Kidney Neoplasms/physiopathology*
9.Temporal therapy utilizing exosomes derived from M2 macrophages demonstrates enhanced efficacy in alleviating neuropathic pain in diabetic rats
Wei WEI ; Jun FANG ; Baozhong YANG ; Chenlong CUI ; Jiacheng WEI ; Yating XUE
The Korean Journal of Pain 2025;38(1):14-28
Background:
Diabetic pain patients have increased pain at night. Exosomes can relieve neuropathic pain. This study aimed to investigate the efficacy of exosome administration at different time points in relieving diabetic neuropathic pain (DNP) in rats.
Methods:
M2 macrophages from bone marrow were induced in mice and exosomes were extracted. A diabetic rat model was induced using streptozotocin, with the mechanical withdrawal threshold (MWT) of the rats beingmeasured at ≤ 80% of the basal value after 14 days, indicating successful construction of the DNP rat model.Exosomes were administered on three consecutive days at ZT0 (zeitgeber time) and ZT12. Parameters including blood glucose levels, body weight, MWT, and thermal withdrawal latency (TWL) were assessed in the rats. The lumbar spinal cord of rats was examined on days 21 and 28 to measure inflammatory factors and observe the expression of M1 and M2 microglia. Furthermore, microglia were exposed to lipopolysaccharide (LPS) and LPS + exosomes in a controlled in vitro setting to assess alterations in microglia phenotype involving the NF-kB p65 andIKBα inflammatory signaling pathways.
Results:
The findings revealed that administration of exosomes during the rat resting period at ZT12 resulted in increased MWT and TWL, as well as a shift in microglia polarization towards the M2 phenotype. In vitro analysis indicated that exosomes influenced microglia polarization and suppressed the phosphorylation of NF-kB p65 andIKBα.
Conclusions
Temporal therapy with exosomes effectively reduces pain in DNP rats by polarizing microglia andaffecting NF-kB p65 and IKBα signaling pathways.
10.Severe malnutrition during pregnancy complicated with acute pyelonephritis causing sepsis, refractory septic shock and multiple organ failure: A case report.
Fangfei XIE ; Hong QIAO ; Boya LI ; Cui YUAN ; Fang WANG ; Yu SUN ; Shuangling LI
Journal of Peking University(Health Sciences) 2025;57(1):202-207
This study reports the diagnosis and treatment of a 26-year-old pregnant woman with severe malnutrition combined with acute pyelonephritis causing sepsis, refractory septic shock and multiple organ failure. A female patient, 26 years old, was admitted to hospital mainly due to "menelipsis for more than 19 weeks, nausea and vomiting for 20 days, fever with fatigue for 3 days". At the end of 19 weeks of intrauterine pregnancy, the patient presented with fever accompanied by urinary tract irritation. Laboratory tests showed elevated inflammatory indicators, and ultrasonography showed bilateral pelvicalyceal dilation. She was diagnosed with acute pyelonephritis, sepsis, acute kidney injury (AKI) and severe malnutrition. After a whole-hospital consultation, the patient was treated with meropenem and vancomycin as antimicrobial therapy, and bilateral nephrostomy drainage was performed simultaneously. After that, the patient suffered a sudden decrease in blood pressure, blood oxygen saturation, and rapid heart rate. Septic shock with multiple organ dysfunction was considered, and she was transferred to intensive care unit (ICU) immediately. After the patient was transferred to ICU, emergency tracheal intubation and ventilator-assisted ventilation were performed. Rapid fluid resuscitation was administered for the patient. While pulse indicator continuous cardiac output (PICCO) monitoring was performed, norepinephrine, terlipressin, and methylene blue were administered to maintain peripheral vascular resistance. Since the patient developed septic cardiomyopathy and cardiogenic shock later, levosimendan and epinephrine were admi-nistered to improve cardiac function. While etiological specimens were delivered, meropenem, teicoplanin and caspofungin were given as initial empiric antimicrobial therapy. Unfortunately, the intrauterine fetal death occurred on the night of admission to ICU. On the 3rd day of ICU admission, a still-born child was delivered vaginally with 1/5 defect of the fetal membrane. On the 6th day of ICU admission, the patient had fever again with elevated inflammatory indicators. After excluding infection in other parts, intrau-terine infection caused by incomplete delivery of fetal membrane was considered. Then emergency uterine curettage was performed and the infection gradually improved. Later the laboratory results showed that the nephrostomy drainage was cultured for Escherichia coli and uterine, cervical and vaginal secretions were cultured for Candida albicans. Due to severe infection and intrauterine incomplete abortion, the patient developed disseminated intravascular coagulation (DIC). Active antimicrobial therapy and blood product supplement were given. However, the patient was critically ill with significant decrease in hemoglobin and platelets combined with multiple organ failure. Thrombotic microangiopathy (TMA) was not excluded yet, so plasma exchange was performed for the patient in order not to delay treatment. The patient underwent bedside continuous renal replacement therapy (CRRT) for AKI. The patient was complicated with acute liver injury, and the liver function gradually returned to normal after liver protection, antimicrobial therapy and other treatments. Due to the application of large doses of vasoactive drugs, the extremities of the patient gradually developed cyanosis and ischemic necrosis. Local dry gangrene of the bilateral toes remained at the time of discharge. In general, the patient suffered from septic shock, cardiogenic shock, combined with DIC and multiple organ dysfunction. After infection source control, antimicrobial therapy, uterine curettage, blood purification treatment, nutritional and metabolic support, the patient was discharged with a better health condition.
Humans
;
Female
;
Pyelonephritis/complications*
;
Pregnancy
;
Adult
;
Multiple Organ Failure/etiology*
;
Shock, Septic/etiology*
;
Sepsis/etiology*
;
Pregnancy Complications
;
Pregnancy Complications, Infectious
;
Malnutrition/complications*

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