1.In situ Analytical Techniques for Membrane Protein Interactions
Zi-Yuan KANG ; Tong YU ; Chao LI ; Xue-Hua ZHANG ; Jun-Hui GUO ; Qi-Chang LI ; Jing-Xing GUO ; Hao XIE
Progress in Biochemistry and Biophysics 2025;52(5):1206-1218
Membrane proteins are integral components of cellular membranes, accounting for approximately 30% of the mammalian proteome and serving as targets for 60% of FDA-approved drugs. They are critical to both physiological functions and disease mechanisms. Their functional protein-protein interactions form the basis for many physiological processes, such as signal transduction, material transport, and cell communication. Membrane protein interactions are characterized by membrane environment dependence, spatial asymmetry, weak interaction strength, high dynamics, and a variety of interaction sites. Therefore, in situ analysis is essential for revealing the structural basis and kinetics of these proteins. This paper introduces currently available in situ analytical techniques for studying membrane protein interactions and evaluates the characteristics of each. These techniques are divided into two categories: label-based techniques (e.g., co-immunoprecipitation, proximity ligation assay, bimolecular fluorescence complementation, resonance energy transfer, and proximity labeling) and label-free techniques (e.g., cryo-electron tomography, in situ cross-linking mass spectrometry, Raman spectroscopy, electron paramagnetic resonance, nuclear magnetic resonance, and structure prediction tools). Each technique is critically assessed in terms of its historical development, strengths, and limitations. Based on the authors’ relevant research, the paper further discusses the key issues and trends in the application of these techniques, providing valuable references for the field of membrane protein research. Label-based techniques rely on molecular tags or antibodies to detect proximity or interactions, offering high specificity and adaptability for dynamic studies. For instance, proximity ligation assay combines the specificity of antibodies with the sensitivity of PCR amplification, while proximity labeling enables spatial mapping of interactomes. Conversely, label-free techniques, such as cryo-electron tomography, provide near-native structural insights, and Raman spectroscopy directly probes molecular interactions without perturbing the membrane environment. Despite advancements, these methods face several universal challenges: (1) indirect detection, relying on proximity or tagged proxies rather than direct interaction measurement; (2) limited capacity for continuous dynamic monitoring in live cells; and (3) potential artificial influences introduced by labeling or sample preparation, which may alter native conformations. Emerging trends emphasize the multimodal integration of complementary techniques to overcome individual limitations. For example, combining in situ cross-linking mass spectrometry with proximity labeling enhances both spatial resolution and interaction coverage, enabling high-throughput subcellular interactome mapping. Similarly, coupling fluorescence resonance energy transfer with nuclear magnetic resonance and artificial intelligence (AI) simulations integrates dynamic structural data, atomic-level details, and predictive modeling for holistic insights. Advances in AI, exemplified by AlphaFold’s ability to predict interaction interfaces, further augment experimental data, accelerating structure-function analyses. Future developments in cryo-electron microscopy, super-resolution imaging, and machine learning are poised to refine spatiotemporal resolution and scalability. In conclusion, in situ analysis of membrane protein interactions remains indispensable for deciphering their roles in health and disease. While current technologies have significantly advanced our understanding, persistent gaps highlight the need for innovative, integrative approaches. By synergizing experimental and computational tools, researchers can achieve multiscale, real-time, and perturbation-free analyses, ultimately unraveling the dynamic complexity of membrane protein networks and driving therapeutic discovery.
2. Lycium barbarian seed oil activates Nrf2/ARE pathway to reduce oxidative damage in testis of subacute aging rats
Rui-Ying TIAN ; Wen-Xin MA ; Zi-Yu LIU ; Hui-Ming MA ; Sha-Sha XING ; Na HU ; Chang LIU ; Biao MA ; Jia-Yang LI ; Hu-Jun LIU ; Chang-Cai BAI ; Dong-Mei CHEN
Chinese Pharmacological Bulletin 2024;40(3):490-498
Aim To explore the effects of Lycium berry seed oil on Nrf2/ARE pathway and oxidative damage in testis of subacute aging rats. Methods Fifty out of 60 male SD rats, aged 8 weeks, were subcutaneously injected with 125 mg • kg"D-galactosidase in the neck for 8 weeks to establish a subacute senescent rat model. The presence of senescent cells was observed using P-galactosidase ((3-gal), while testicular morphology was examined using HE staining. Serum levels of testosterone (testosterone, T), follicle-stimulating hormone ( follicle stimulating hormone, FSH ) , luteinizing hormone ( luteinizing hormone, LH ) , superoxide dis-mutase ( superoxide dismutase, SOD ) , glutathione ( glutathione, GSH) and malondialdehyde ( malondial-dehyde, MDA) were measured through ELISA, and the expressions of factors related to aging, oxidative damage, and the Nrf2/ARE pathway were assessed via immunohistochemical analysis and Western blotting. Results After successfully identifying the model, the morphology of the testis was improved and the intervention of Lycium seed oil led to a down-regulation in the expression of [3-gal and -yH2AX. The serum levels of SOD, GSH, T, and FSH increased while MDA and LH decreased (P 0. 05) . Additionally, there was an up-regulated expression of Nrf2, GCLC, NQOl, and SOD2 proteins in testicular tissue ( P 0. 05 ) and nuclear expression of Nrf2 in sertoli cells. Conclusion Lycium barbarum seed oil may reduce oxidative damage in testes of subacute senescent rats by activating the Nrf2/ARE signaling pathway.
3.Analysis of the predictive value of the protein level of oncogenes C-myc,N-ras,PLK 1,and FGF2 in the serum of hepatitis B-related liver cancer patients on the prognosis after TACE
Yang ZHOU ; Xing YIN ; Min FU ; Huan CHANG ; Yanli XING ; Yixing LI ; Xianzhe YIN
International Journal of Laboratory Medicine 2024;45(3):347-352,357
Objective To investigate the predictive value of serum oncogene[proliferation-related gene(C-myc),transformation gene(N-ras),silk/threonine kinase 1(PLK1),fibroblast growth factor 2(FGF2)]protein levels in patients with hepatitis B associated hepatocellular carcinoma(HCC)after hepatic arterial chemoem-bolization(TACE).Methods A total of 127 patients with hepatitis B-associated hepatocellular carcinoma ad-mitted to a hospital from July 2016 to January 2021 were selected and divided into death group and survival group according to the follow-up results.The serum oncogene C-myc,N-ras,PLK1 and FGF2 protein levels were determined by double-antibody sandwich enzyme-linked immunosorbent assay.Univariate and multivari-ate Cox analysis were used to analyze the risk factors of serum oncogene C-myc,N-ras,PLK1 and FGF2 pro-tein levels in patients with hepatitis B-associated hepatocellular carcinoma after TACE.The receiver operating characteristic curve was used to evaluate the prognostic value of the serum oncogene C-myc,N-ras,PLK1 and FGF2 protein levels,and the patients were divided into high expression group and low expression group ac-cording to the corresponding cutoff value.Kaplan-Meier survival curve was used to evaluate the prognosis of different serum oncogene C-myc,N-ras,PLK1 and FGF2 protein level.Results Multivariate Cox regression a-nalysis indicated that TNM stage Ⅲ to Ⅳ(HR=2.998,95%CI:1.239-7.257),portal vein metastasis(HR=3.737,95%CI:1.941-7.193),abdominal metastasis(HR=3.482,95%CI:1.709-7.097),Child-Pugh grade B(HR=2.587,95%CI:1.045-6.406),high serum oncogene C-myc protein level(HR=1.224,95%CI:1.090-1.374),high serum oncogene N-ras protein level(HR=1.218,95%CI:1.097-1.353),high serum oncogene PLK1 protein level(HR=1.237,95%CI:1.110-1.379)and high serum oncogene FGF2 protein level(HR=1.141,95%CI:1.060-1.228)were independent risk factors for the prognosis of hepatitis B-asso-ciated hepatocellular carcinoma patients after TACE(all P<0.05).The overall survival rate of low expression group of serum oncogene C-myc,N-ras,PLK1,FGF2 protein level was significantly higher than that of high expression group of serum oncogene C-myc,N-ras,PLK1,FGF2 protein level,the difference was statistically significant(all P<0.001).Conclusion Serum oncogene C-myc,N-ras,PLK1,FGF2 protein levels have predic-tive value for the prognosis of patients with HBV-related liver cancer after TACE.
4.Efficacy and safety of nicorandil and ticagrelor de-escalation after percutaneous coronary intervention for elderly patients with acute coronary syndrome
Xiang SHAO ; Ning BIAN ; Hong-Yan WANG ; Hai-Tao TIAN ; Can HUA ; Chao-Lian WU ; Bei-Xing ZHU ; Rui CHEN ; Jun-Xia LI ; Tian-Chang LI ; Lu MA
Medical Journal of Chinese People's Liberation Army 2024;49(1):75-81
Objective To explore the efficacy and safety of ticagrelor de-escalation and nicorandil therapy in elderly patients with acute coronary syndrome(ACS)after percutaneous coronary intervention(PCI).Methods A total of 300 elderly patients with ACS were selected from the Sixth and Seventh Medical Center of Chinese PLA General Hospital and Beijing Chaoyang Integrative Medicine Emergency Rescue and First Aid Hospital from November 2016 to June 2019,including 153 males and 147 females,aged>65 years old.All the patients received PCI,and all had double antiplatelet therapy(DAPT)scores≥2 and a new DAPT(PRECISE-DAPT)score of≥25.All patients were divided into two groups by random number table method before operation:ticagrelor group(n=146,ticagrelor 180 mg load dose followed by PCI,and ticagrelor 90 mg bid after surgery)and ticagrelor de-escalation + nicorandil group(n=154,ticagrelor 180 mg load dose followed by PCI,ticagrelor 90 mg bid+nicorandil 5 mg tid after surgery,changed to ticagrelor 60 mg bid+ nicorandil 5 mg tid 6 months later).Follow-up was 12 months.The composite end points of cardiovascular death,myocardial infarction and stroke,the composite end points of mild hemorrhage,minor hemorrhage,other major hemorrhage and major fatal/life-threatening hemorrhage as defined by the PLATO study,and the composite end points of cardiovascular death,myocardial infarction,stroke and bleeding within 12 months in the two groups were observed.Results The comparison of general baseline data between the two groups showed no statistically significant difference(P>0.05).There was also no significant difference in the composite end points of cardiovascular death,myocardial infarction and stroke between the two groups(P>0.05).The cumulative incidence of bleeding events in ticagrelor de-escalation + nicorandil group was significantly lower than that in ticagrelor group(P<0.05),while the composite end points of cardiovascular death,myocardial infarction,stroke and bleeding were also significantly lower than those in tecagrelor group(P<0.05).Conclusion In elderly patients with ACS,the treatment of ticagrelor de-escalation + nicorandil after PCI may not increase the incidence of ischemic events such as cardiovascular death,myocardial infarction or stroke,and it may reduce the incidence of hemorrhagic events.
5.Application of"rotation-correction loop technique"in the retrieval of complex inferior vena cava filters
Jie HU ; Maolin QIAO ; Qinqin TIAN ; Heng WANG ; Sheng YAN ; Wenbo ZHAO ; Yongbin SHI ; Peilu SHI ; Miao XING ; Haifeng LI ; Haijiang JIN ; Ping WANG ; Wenkai CHANG ; Yuwen WANG ; Honglin DONG
Journal of Interventional Radiology 2024;33(3):289-294
Objective To discuss the application of the"rotating guidewire and correcting the filter recovery hook direction technique"("rotation-correction loop technique"for short),a technique invented by the authors in clinical practice,in the retrieval of complex inferior vena cava filter(IVCF),and to discuss its technical skills and advantages.Methods The clinical data of 417 patients carrying an IVCF,who were admitted to the Department of Vascular Surgery of Second Hospital of Shanxi Medical University of China to retrieve IVCF between January 2022 and December 2022,were retrospectively analyzed.Taking the time spent on the retrieval of IVCF and the intraoperative radiation dose as the evaluation indicators,the advantages and disadvantages of the standard filter retrieval technique,the"rotation-correction loop technique"and the other loop-assisted techniques were compared.Results Both the intraoperative radiation dose and the time spent on the retrieval of IVCF using"rotation-correction loop technique"were remarkably lower than those of other loop-assisted techniques(P<0.000 1).Conclusion For the retrieval of complex IVCF,especially for the IVCF which is heavily tilted and/or its recovered hook is attached to the vascular wall,the use of"rotation-correction loop technique"can shorten the time spent on the the retrieval of IVCF and reduce the intraoperative radiation dose.This technique carries high safety and practicability,the device is simple and it can be manipulated by single physician,which is conducive to clinical application and promotion.(J Intervent Radiol,2024,33:289-294)
6.Characteristics of event-related potential and frequency on working memory of post-stroke aphasia
Xing HUANG ; Jingling CHANG ; Zihan ZHANG ; Ying LI
Chinese Journal of Rehabilitation Theory and Practice 2024;30(3):316-325
Objective To explore the task-state electroencephalogram(EEG)characteristics of working memory in patients with post-stroke aphasia(PSA). Methods From September,2020 to February,2021,a total of eight patients with PSA(PSA group)and eight healthy adults(HC group)were recruited to collect EEG and memory scale data.The EEG data of working memory task-states were used to analyze the characteristics of the EEG frequency band indicators in time domain event-related potentials(ERP)and frequency;and the correlation with the items in the memory scale. Results Finally,five patients and five controls were included.N1 and P2 components were induced in the frontal area,and P300 components were induced in the parieto-occipital area.Compared with HC group,the activation of N1 and P2 increased in central prefrontal region,while the activity of P300 decreased in the right parieto-occipital re-gion in PSA group(|t|>2.193,P<0.05).The energy of theta band decreased in the right prefrontal region and the central parieto-occipital region,the energy of alpha1 band decreased in the left parieto-occipital region,and the energy of gamma band increased in the left central region(t>2.398,P<0.05).The energy of gamma band correlated with immediate recall(r = 0.914,P = 0.030)and correct recognition(r = 0.931,P = 0.022)of Auditory Verbal Learning Test,and inverting(r = 0.924,P = 0.025)and anterograde(r = 0.889,P = 0.044)of Digit Span Test. Conclusion Visual working memory task can activate the compensatory processing activity of memory related brain re-gions after PSA,which can be used as an objective indication for the evaluation of PSA working memory related research.There is close relationship between language impairment and working memory.
7.Molecular Mechanism of Action of Astragaloside Ⅳ in Modulating Pyroptosis to Attenuate Intestinal Ischemia-reperfusion Injury Based on Experimental Validation
Liya CHANG ; Yufang LENG ; Zicen ZHAO ; Yu WANG ; Yang XING ; Dongbin LI
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(19):116-123
ObjectiveTo investigate the mechanism of astragaloside-Ⅳ (AS-Ⅳ) in regulating pyroptosis to alleviate intestinal ischemia-reperfusion injury (IRI) by combining network pharmacology and in vivo experiments. MethodFirstly, the corresponding target genes of AS-Ⅳ were obtained from TraditionalChineseMedicineSystemsPharmacology(TCMSP) database and Swiss Target Prediction database, and the target genes related to intestinal IRI and Pyroptosis were obtained from GeneCards database, and the common target genes of the three were obtained by drawing Venn diagrams through unspiralized website. Protein-protein interaction (PPI) network was constructed by STRING database and Cytoscape software to screen common target genes and imported into Cytoscape software to obtain core target genes. Microbiotics platform was used for gene ontology(GO) and Kyoto encyclopedia of genes and genomes(KEGG) enrichment analysis and prediction of the mechanism of action of AS-Ⅳ in regulating Pyroptosis to alleviate intestinal IRI. Then C57/BL6J mice were randomly divided into 5 groups normal group, model group(IR), drug administration group (IR+AS-Ⅳ), nucleotide-binding oligomerization structural domain-like receptor protein 3 (NLRP3) agonist NSS group (IR+AS-Ⅳ+NSS), and NLRP3 inhibitor MCC950 group (IR+AS-Ⅳ+MCC950) by using a randomized numerical table method. The intestinal IRI model was established by clamping the superior mesenteric artery for 45 min and resuming perfusion for 2 h in the model group, the drug administration group, the NLRP3 agonist NSS group, and the NLRP3 inhibitor MCC950 group, and the normal group was only separated from the vessels without clamping. The administration group, the NLRP3 agonist NSS group, and the NLRP3 inhibitor MCC950 group were gavaged with astragaloside dissolved in 0.1% dimethylsulfoxide (50 mg·kg-1) for 3 consecutive days before modeling, with the last gavage 2 h before modeling, and the remaining two groups were gavaged with equal amounts of saline. The NLRP3 agonist NSS group was injected intraperitoneally with 4 mg·kg-1 of NSS 1 h before modeling, and the NLRP3 inhibitor MCC950 group was injected intraperitoneally with 10 mg·kg-1 of MCC950 1 h before modeling.The mice were put to death by reperfusion for 2 h, and intestinal tissues were obtained. The levels of IL-18 and IL-1β were detected by enzyme linked immunosorbent assay(ELISA), and the protein expression of thioredoxin-binding protein (TXNIP), NLRP3, Caspase-1 and pyrocatechin D (GSDMD) were detected by Western blot, and the pathological changes of intestinal tissues were evaluated by Chiu's score. ResultNetwork pharmacological analysis showed that there were 1599 targets of intestinal IRI, 199 targets of AS-Ⅳ action, 197 targets of pyroptosis, and 20 targets common to all three. There were 10 core targets, including NLRP3, TXNIP, silencing information regulator 1 (SIRT1), high mobility group protein 1 (HMGB1), interleukin-18 (IL-18), GSDMD, and metallo matrix protease-9 (MMP-9),et al. The results of in vivo experiments showed that compared with the normal group, Chiu's score was elevated in the model group, the levels of IL-18,IL-1β inflammatory factors in mouse intestinal tissues were elevated (P<0.05), and the protein expression levels of TXNIP, NLRP3, Caspase-1, and GSDMD were elevated (P<0.05). Compared with the model group,Chiu's score was decreased in the administered group and NLRP3 inhibitor MCC950 group,the level of IL-18,IL-1β inflammatory factors in the intestinal tissue of mice was decreased(P<0.05), and the level of TXNIP,NLRP3,Caspase-1,GSDMD protein expression was decreased(P<0.05). Compared with the administered group, Chiu's score was elevated in the NLRP3 agonist NSS group, the levels of IL-18, IL-1β inflammatory factors in mouse intestinal tissues were elevated (P<0.05), and the protein expression levels of NLRP3, Caspase-1, and GSDMD were elevated (P<0.05). Compared with the NLRP3 inhibitor MCC950 group, the NLRP3 agonist NSS group had elevated Chiu's scores, elevated levels of IL-18,IL-1β inflammatory factors in mouse intestinal tissues (P<0.05), and elevated levels of TXNIP,NLRP3, Caspase-1, and GSDMD protein expression (P<0.05). ConclusionNetwork pharmacological predictions were consistent with the results of in vivo experiments, and astragaloside attenuated intestinal ischemia-reperfusion injury by inhibiting cellular pyroptosis through the TXNIP-NLRP3 signaling pathway.
8.Biological scaffold materials and printing technology for repairing bone defects
Xiangyu KONG ; Xing WANG ; Zhiwei PEI ; Jiale CHANG ; Siqin LI ; Ting HAO ; Wanxiong HE ; Baoxin ZHANG ; Yanfei JIA
Chinese Journal of Tissue Engineering Research 2024;28(3):479-485
BACKGROUND:In recent years,with the development of biological scaffold materials and bioprinting technology,tissue-engineered bone has become a research hotspot in bone defect repair. OBJECTIVE:To summarize the current treatment methods for bone defects,summarize the biomaterials and bioprinting technology for preparing tissue-engineered bone scaffolds,and explore the application of biomaterials and printing technology in tissue engineering and the current challenges. METHODS:Search terms were"bone defect,tissue engineering,biomaterials,3D printing technology,4D printing technology,bioprinting,biological scaffold,bone repair"in Chinese and English.Relevant documents published from January 1,2009 to December 1,2022 were retrieved on CNKI,PubMed and Web of Science databases.After being screened by the first author,high-quality references were added.A total of 93 articles were included for review. RESULTS AND CONCLUSION:The main treatment methods for bone defects include bone transplantation,membrane-guided regeneration,gene therapy,bone tissue engineering,etc.The best treatment method is still uncertain.Bone tissue engineering technology is a new technology for the treatment of bone defects.It has become the focus of current research by constructing three-dimensional structures that can promote the proliferation and differentiation of osteoblasts and enhance the ability of bone formation.Biological scaffold materials are diverse,with their characteristics,advantages and disadvantages.A single biological material cannot meet the demand for tissue-engineered bone for the scaffold.Usually,multiple materials are combined to complement each other,which is to meet the demand for mechanical properties while taking into account the biological properties of the scaffold.Bioprinting technology can adjust the pore of the scaffold,build a complex spatial structure,and is more conducive to cell adhesion,proliferation and differentiation.The emerging 4D printing technology introduces"time"as the fourth dimension to make the prepared scaffold dynamic.With the synchronous development of smart materials,4D printing technology provides the possibility of efficient repair of bone defects in the future.
9.Application of cypropofol and propofol combined with low-dose alfentanil in gastroenteroscopy
Yu WANG ; Yufang LENG ; Dongbin LI ; Yang XING ; Liya CHANG ; Zicen ZHAO
Journal of Army Medical University 2024;46(23):2642-2648
Objective To investigate the anesthetic effects and adverse effects of cypropofol and propofol combined with alfentanil,respectively,for gastroenteroscopy.Methods A total of 162 patients who underwent elective gastroenteroscopy at the Gastrointestinal Endoscopy Center of the First Hospital of Lanzhou University from January to February 2024 were enrolled,including 86 males and 76 females,at an age of 18~65 years old,with a BMI value of 18~30 kg/m2,and ASA grade ≤ Ⅱ.They were randomly divided into propofol group(Group P)and cypropofol group(Group C),with 81 cases in each group.All patients were sedated with 0.7 μg/kg alfentanil,and in 30 s later,2 mg/kg propofol and 0.4 mg/kg cypropofol was intravenously dripped into Group P and Group C,respectively.When the modified alertness/sedation score(MOAA/S)≤1,a gastroscope was started to insert.The related indicators,including total procedure time,successful cases of sedation,induction time and awakening time,heart rate,blood pressure,and pulse oximetry saturation were recorded,occurrence of adverse reactions such as hypotension,respiratory depression,injection pain,intraoperative body movement,nausea and vomiting were observed,and the satisfaction of endoscopists and of patients to anesthesia were recorded and compared between the 2 groups.Results There were no statistical differences in the success rate of sedation,induction time and awakening time between the 2 groups.The patients of the Group C had more stable intraoperative vital signs,statistically lower incidences of injection pain,respiratory depression and hypotension(P<0.05),and increased satisfaction for anesthesia(P<0.05)when compared with those in Group P.No obvious difference were observed in the satisfaction of endoscopist to anesthesia between the 2 groups.Conclusion In combination with small-dose alfentanil,0.4 mg/kg cypropofol shows similar sedation effect as 2 mg/kg propofol in gastroenteroscopy,with comparable induction and awakening time.Cypropofol has more advantages in stable intraoperative vital signs,less adverse effects such as low blood pressure,respiratory depression and injection pain,higher the patient satisfaction,which is worthy of clinical promotion.
10.Application Progress of RNA Fluorescence Aptamers in Biosensing and Imaging
Xing-Chen QIU ; Cun-Xia FAN ; Rui BAI ; Yu GU ; Chang-Ming LI ; Chun-Xian GUO
Chinese Journal of Analytical Chemistry 2024;52(4):481-491
RNA fluorescence aptamers are RNA sequences that can specifically bind to non-toxic,cell permeable,and self-fluorescent target molecules and activate their luminescent properties.These aptamers provide powerful tools for biosensing and imaging researches due to their simple structure,easy synthesis,and easy transfection.This article summarized the characteristics and development history of various RNA fluorescent aptamers,including Malachite Green,Spinach,Broccoli,Mango,Corn,and Pepper family,as well as their corresponding fluorescent groups.The applications of RNA fluorescent aptamers were also reviewed from two aspects:extracellular detection and cell imaging.This review might provide guidance for labeling,detection and interactions of molecules from proof of concept and clinical assessment to practical clinical and biomedical applications.

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