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.PES1 Repression Triggers Ribosomal Biogenesis Impairment and Cellular Senescence Through p53 Pathway Activation
Chang-Jian ZHANG ; Yu-Fang LI ; Feng-Yun WU ; Rui JIN ; Chang NIU ; Qi-Nong YE ; Long CHENG
Progress in Biochemistry and Biophysics 2025;52(7):1853-1865
ObjectiveThe nucleolar protein PES1 (Pescadillo homolog 1) plays critical roles in ribosome biogenesis and cell cycle regulation, yet its involvement in cellular senescence remains poorly understood. This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role. MethodsInitially, we assessed PES1 expression patterns in two distinct senescence models: replicative senescent mouse embryonic fibroblasts (MEFs) and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells. Subsequently, PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types. Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays, respectively. The expression of senescence-associated proteins (p53, p21, and Rb) and SASP factors (IL-6, IL-1β, and IL-8) were analyzed by Western blot or qPCR. Furthermore, Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology. ResultsPES1 expression was significantly downregulated in senescent MEFs and HepG2 cells. PES1 knockdown resulted in decreased EdU-positive cells and increased SA‑β‑gal-positive cells, indicating proliferation inhibition and senescence induction. Mechanistically, PES1 suppression activated the p53-p21 pathway without affecting Rb expression, while upregulating IL-6, IL-1β, and IL-8 production. Notably, PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress, as evidenced by aberrant nucleolar morphology. ConclusionOur findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent (but Rb-independent) cellular senescence, highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.
3.Evaluation progress of the application of staplers in thoracoscopic lung surgery
Shenghui LI ; Yijiu REN ; Hang SU ; Minglei YANG ; Guofang ZHAO ; Yongxiang SONG ; Xuefei HU ; Deping ZHAO ; Qi XUE ; Chang CHEN
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(05):709-713
Compared to traditional suturing, lung stapling using automatic staplers offers advantages such as smaller trauma, faster wound healing, ease of operation, and lower complication rates, making it widely used in clinical practice. However, there are significant differences in bronchial tissue thickness at different anatomical locations, and the market is flooded with various types of staplers. Currently, there is a lack of recommended stapling schemes for bronchial staplers at different anatomical locations. This article reviews the development and application of automatic staplers and summarizes some types of staplers that are currently used in clinical practice, with the aim of promoting the formation of individualized stapler selection protocols for minimally invasive thoracic surgery based on the Chinese population.
4.Portable Electrochemical Sensor for Sensitive Detection of Azo Dyes Sunset Yellow and Tartrazine
Xue-Qing CHANG ; Zi-Qi WANG ; Li-Ping LU
Chinese Journal of Analytical Chemistry 2024;52(1):62-71
A polymethionine(p-Met)-modified laser-induced graphene(LIG)electrode was constructed and integrated with portable electrochemical workstations and handheld computer to achieve on-site,simultaneous detection of azo dyes sunset yellow(SY)and tartrazine(Tz)in environmental water.Firstly,the sensor interface with the best electrical conductivity was obtained by optimizing the laser processing parameters,and then the electrochemical responses of SY and Tz were improved by electropolymerization of methionine on the surface of LIG.Finally,a portable electrochemical sensor platform was built by connecting p-Met/LIG,a small electrochemical workstation and a handheld computer application program.Differential pulse voltammetry(DPV)was used to determine these two dyes.SY showed a good linear relationship in the concentration range of 0.2-20 μmol/L and 20-100 μmol/L,the detection limit was as low as 0.001 μmol/L.Tz showed a good linear relationship in concentration range of 0.3-40 μmol/L and 40-100 μmol/L,and the detection limits was as low as 0.005 μmol/L.p-Met/LIG also had excellent anti-interference performance and reproducibility.The portable electrochemical platform was applied to real-time detection of real water samples,and the results showed that the platform was expected to be applied in field detection of SY and Tz in real environmental water bodies.
5.Reconstruction and analysis of K-Clip surgery process based on finite element method
Hao SHI ; Wenbin OUYANG ; Shiguo LI ; Qi LI ; Fengwen ZHANG ; Yao LIU ; Wenxin LU ; Chang LIU ; Shaojie ZHANG ; Xiangbin PAN
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2024;31(01):44-50
Objective To investigate the effects of different types of tricuspid regurgitation, implantation positions, and device models on the treatment outcomes of K-Clip for tricuspid regurgitation using numerical simulations. Methods Three-dimensional reconstruction of the heart model was performed based on CT images. Two different regurgitation orifices were obtained by modifying the standard parameterized tricuspid valve leaflets and chordae tendineae. The effects of different K-Clip models at different implantation positions (posterior leaflet midpoint, anterior-posterior commissure, anterior leaflet midpoint, posterior septal commissure) were simulated using commercial explicit dynamics software Ls-Dyna. Conclusion For the two types of regurgitation in this study, clipping at the posterior leaflet midpoint resulted in a better reduction of the regurgitation orifice (up to 75% reduction in area). Higher clamping forces were required for implantation at the anterior leaflet midpoint and posterior septal commissure, which was unfavorable for the smooth closure of the clipping components. There was no statistical difference in the treatment outcomes between the 18T and 16T K-Clip components, and the 16T component required less clamping force. Therefore, the use of the 16T K-Clip component is recommended.
6.Research progress on the correlation between imaging features and the molecular subtype,histopathology,clinical prognosis of ductal carcinoma in situ of the breast
Qi LIU ; Cai CHANG ; Jiawei LI
China Oncology 2024;34(2):201-209
Ductal carcinoma in situ(DCIS),a pathological type of breast cancer that is limited to the terminal ducts of the breast without breaking through the basement membrane,is considered as the precursor of invasive ductal carcinoma(IDC).When DCIS breaks through the basement membrane and invades surrounding tissues,it can form infiltrating lesions.If the maximum diameter of a single infiltrating lesion is less than 1mm or the maximum diameter of multiple infiltrating lesions is less than 1mm,it is defined as ductal carcinoma in situ with microinvasion(DCIS-Mi).About 12%-40%of untreated and intervened DCIS will progress to IDC,and DCIS and IDC can also coexist.However,there is a considerable portion of DCIS that never progresses with good prognosis.Recently,overdiagnosis and overtreatment of DCIS have become the research hotspots.The histological grade of DCIS is mainly based on the morphology of the nucleus,which is divided into three nuclear levels:low,medium,and high.There are also significant differences in receptor expression and molecular type distribution between DCIS,DCIS-Mi,and IDC.For DCIS with or without microinvasion as well as different histological grades,there are many controversies about the treatment regimen,clinical prognosis and risk.The development of modern imaging technology has achieved preliminary evaluation of histological grading,infiltration status,and prognosis prediction of DCIS.The most commonly used breast imaging techniques in clinical practice currently include mammography(MG),ultrasound(US),and magnetic resonance imaging(MRI).The imaging principles of these three techniques are different,and each has its own advantages and disadvantages in breast disease imaging diagnosis.However,they can complement each other and play an important role in disease diagnosis,treatment,and prognosis evaluation.Mammography has the advantages of safety,reliability and good repeatability.It is the preferred screening method for breast cancer recommended by international guidelines.The main manifestations of DCIS on MG can be divided into non calcified lesions and calcified lesions.On US,the main manifestations are lesions and non-lesion type,which can be further divided into hypoechoic changes,calcification,ductal changes,and structural disorders and distortions.MRI has higher sensitivity in detecting DCIS without calcification and multifocal DCIS compared with MG,and has higher accuracy in evaluating the lesion range.However,there are also shortcomings such as low diagnostic specificity and insensitivity to microcalcification display.In addition,radiomics has great potential in the histopathological evaluation,prediction,and guidance of individualized precision treatment of DCIS.In the current era of precision medicine,image features,histopathology,molecular genes,etc.are increasingly significant in predicting the prognosis of breast cancer.The early accurate diagnosis and molecular type of DCIS are also extremely important in clinical work.It has become a consensus in clinical treatment to predict the potential benefits of different treatments through molecular typing,histological grade,and imaging findings,in order to develop the most suitable personalized treatment plan.This article reviewed the correlation between imaging features and the molecular subtype,histopathology and prognosis of DCIS.
7.Analyses of DXA in diagnosing osteoporosis of postmenopausal rheumatoid arthritis patients in Qinghai region and the risk factors of them
Jing FANG ; Youyun LIU ; Shengping QI ; Zuorei LI ; Fuyan YANG ; Yanbin WANG ; Xudong CHANG ; Qiong HAN ; Jianhui WANG
China Medical Equipment 2024;21(2):23-27
Objective:To investigate the diagnosis of dual-energy X-ray absorptiometry(DXA)for osteoporosis(OP)of postmenopausal patients with rheumatoid arthritis(RA)in Qinghai region and the risk factors of them.Methods:A total of 200 postmenopausal female RA patients who admitted to Qinghai Hospital of Traditional Chinese Medicine from May 2022 to April 2023 were selected.All patients were tested for bone mineral density(BMD)after admission,and lumbar spines L1-L4,whole lumbar,large trochanter,Ward's triangle area,whole body and whole forearm were measured by DXA.According to the results of BMD test,patients whose BMD T values of all body parts-2.5 SD were less or equal to-2.5 were included in the OP group(121 cases),and patients whose BMD T value of all body parts were larger than-2.5 SD were included in the non-OP group(79 cases).The BMD T value of different body parts between two groups of RA patients were compared and analyzed.The area under curve(AUC)of receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficiency of BMD T value for OP.The logistic regression method was adopted to analyze the risk factors that postmenopausal RA patients of Qinghai region occurred OP.Results:The BMD T values of L1,L2,L3,L4,whole lumbar,large trochanter,Ward's triangular area,whole body and whole forearm of OP group were obviously lower than those of the non-OP group.In analysis of ROC curve,the sensitivities of BMD T values of L1,L2,L3,L4,whole lumbar,large trochanter,Ward's triangle area,whole body and forearm were respectively 96.20%,95.22%,90.16%,96.03%,92.01%,89.36%,99.26%,90.02% and 96.03% in diagnosing OP,and the specificities of them were respectively 81.00%,82.19%,85.22%,83.06%,83.06%,90.22%,80.06%,86.23%,83.09%,and the AUC values of them were respectively 0.908,0.905,0.896,0.906,0.903,0.879,0.918,0.901 and 0.906.The results of the logistic-regression analysis showed that advanced age,long disease course,rheumatic activity scores of 28 joints,erythrocyte sedimentation rate and Calcium supplementation were the risk factors of occurring OP in postmenopausal RA patients in Qinghai region.Conclusion:The DXA method that detects BMD of RA patients who occur OP can be used as gold standard to assess OP,and there are many risk factors that affect the occurrence of OP in postmenopausal RA patients of Qinghai region.The clinical work should combine with relative factors to formulate reasonable measure so as to reduce the incidence of OP.
8.Machine learning-based quantitative prediction of drug drug interaction using drug label information
Lu-Hua LIANG ; Yu-Xi XU ; Bei QI ; Lu-Yao WANG ; Chang LI ; Rong-Wu XIANG
The Chinese Journal of Clinical Pharmacology 2024;40(16):2396-2400
Objective To construct machine learning models that can be used to predict AUC fold change(FC)using a database of existing pharmacokinetic(PK)and drug-drug interaction(DDI)information,which can be used to explore the possibility of predicting existing drug interactions and to provide certain rational recommendations for clinical drug use.Methods PK data of DDIs and AUC fold change data were extracted from FDA-approved drug labels.Peptide and pharmacodynamic(PD)information related to drug interactions were retrieved through DrugBank,and PPDT identification of relevant peptide IDs was performed using Protein Resource(UniProt),and a matrix normalization code was used to generate multidimensional vector data that were easy to analysis.The effect of PPDT on the AUC,and the resulting multiplicity change was used as the dependent variable for machine learning model construction.The model with the smallest root mean square error(RMES)value was used for model construction to train a bagged decision tree(Bagged)prediction model.The models were tested using the trained models for some of the drug tests.The models were evaluated by reviewing the available literature findings on detection of drug interaction pairs and analyzing and comparing the predicted values.Results A total of 16 pairs of model drug pairs were tested for the effects of 16 drugs on tacrolimus,and it was found that the accuracy of the prediction of the presence or absence of drug interactions was 81.25%;the prediction results were classified according to the FDA standard classification of the strong and weak for the strength of drug interactions,and the results showed that the prediction of the strength of drug interactions,with a large deviation from the larger prediction was less.Conclusion The evaluation of the model to predict the presence or absence of drug interactions was general;however,after classifying the strengths and weaknesses of drug interactions,the prediction of drug interactions was better,and the prediction results indicated that the model prediction performance has a certain reference value for potential DDI assessment before clinical trials.
9.Mechanism of Mitochondrial Quality Control in Ovarian Aging and Intervention of Traditional Chinese Medicine: A Review
Fei YAN ; Yanfeng LIU ; Qi ZHAO ; Xingtong LIU ; Ying LI ; Chang SHU
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(18):291-298
Ovarian aging is a reproductive endocrine disease caused by a variety of factors leading to a gradual decline in ovarian function until ovarian failure, which seriously affects women's physical and reproductive health and is a major factor leading to female infertility. Mitochondria, the energy metabolism centers of cells, are critical for ovarian functions. Their structural and functional abnormalities are key pathological factors leading to the declined ovarian function. Mitochondrial quality control is an important endogenous regulatory mechanism for the maintenance of mitochondrial homeostasis and the improvement of mitochondrial functions. Abundant studies have shown that the dysregulation of mitochondrial quality control, characterized by mitochondrial oxidative damage, abnormal mitochondrial biogenesis, abnormal mitochondrial dynamics, abnormal mitochondrial autophagy, and dysregulated calcium homeostasis, is closely associated with the occurrence of ovarian hypofunction. Traditional Chinese medicine (TCM) is a treasure of China's medicine, demonstrating remarkable efficacy in the clinical treatment of ovarian aging-related diseases. In recent years, research progress has been achieved in the TCM treatment of ovarian aging by regulating mitochondrial quality control disorders in a multi-target and multi-pathway manner. However, systematic research remains to be carried out regarding the research progress in this field. Therefore, this article reviews the research progress in the TCM treatment of ovarian aging based on mitochondrial quality control, with a view to providing a theoretical basis for studying the clinical efficacy of TCM in the treatment of ovarian aging and a new strategy for the in-depth research on the prevention and treatment of ovarian aging by TCM.
10.Study on Biocompatibility of Graphene Quantum Dots With Macrophages in vitro
Qi LIU ; Hai-Yan XU ; Yu-Xuan SU ; Kai-Hong ZHOU ; Chang-Yan LI
Progress in Biochemistry and Biophysics 2024;51(11):2971-2982
ObjectiveGQDs has become a superstar among zero-dimensional carbon-based materials. As one of the most abundant and important biological elements, its unique optical properties, high dispersion and biocompatibility have attracted extensive attention from scientists. This paper aims to investigate the effect of GQDs on cell viability, apoptosis and inflammatory factor expression in RAW264.7 macrophages and evaluate cell imaging capability of GQDs in vitro, which could provide theoretical basis for the safe application of GQDs in biomedical field. MethodsGraphene oxide was prepared by modified Hummer’s method. H2O2 and W18O49 interacted with each other under hydrothermal conditions to produce hydroxyl radicals, which can cut graphene oxide into GQDs using a top-down approach. The microstructure of GQDs was analyzed in detail by X-ray powder diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy, scanning electron microscopy and Fourier infrared transform. The biocompatibility of GQDs on macrophage was evaluated by CCK-8 and dead/alive staining. Flow cytometry results showed the apoptosis of RAW264.7 macrophages induced by GQDs. mRNA expression of inflammatory factors was evaluated byRT-qPCR. Cell imaging was exhibited by laser scanning confocal. ResultsHydroxyl radicals are produced by H2O2 and W18O49 under hydrothermal conditions, which contribute to cut graphene oxide into 3-5 nm GQDs in one step. The quantum yield of this method is 43%. Fluorescence lifetime of these blue GQDs is 1.67 ns. The Zigzag-type site and defect state of the triplet carbene radical lead to the excitation wavelength dependence of GQDs, and the optimal excitation and emission wavelengths are 330 nm and 400 nm, respectively. The boundary effect and amphiphilicity of quantum dots make GQDs possess abundant functional groups, vacancy defects and high dispersion, which results in GQDs exhibits good water solubility. RAW264.7 macrophages are incubated with different concentration in DEME medium for 24 h, 48 h and 72 h to evaluate cell. The survival rate of RAW264.7 cells is significantly dependent on the concentration and time of GQDs. CCK-8 and dead/alive staining show that GQDs have high biocompatibility. The effect of 200 mg/L GQDs on apoptosis of RAW264.7 cells is revealed by the scatter plot of bivariate flow cytometry. Under the stimulation of LPS+INF‑γ, the expression of TNF-α was increased in RAW264.7 cells, which co-acted with other cytokines to participate in the immune response of RAW264.7 cells in vitro, and mediated the production of IL-1β inflammatory factor in RAW264.7 cells, thereby inducing apoptosis of RAW264.7 cells. The results of RT-qPCR showed that GQDs can inhibit the growth of RAW264.7 cells in vitro, and stimulate them to increase TNF-α expression in RAW264.7 cells, which make cell membrane rupture and produce IL-1β inflammatory factors to induce cell apoptosis. The high biocompatibility of GQDs is attributed to the rich oxygen-containing functional groups (―COOH, ―OH, and C

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