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.ox-LDL Promotes Bidirectional Regulation of Neuronal Apoptosis Through The PCSK9/LRP1 Signaling Pathway
Nai-Qi HE ; Xue-Shan ZHAO ; Qian XU ; Hua-Yu ZHANG ; Zhong REN ; Zhi-Han TANG ; Qiong XIANG ; Lu-Shan LIU
Progress in Biochemistry and Biophysics 2024;51(4):944-958
Obiective Alzheimer’s disease (AD) is a degenerative disease of the central nervous system (CNS) caused by a variety of risk factors. There are various pathological changes, but apoptosis of the neurological meridian cells is one of the most important pathological bases. Hyperlipidemia is a high-risk factor for the development of AD, which can lead to increased levels of oxidized low-density lipoprotein (ox-LDL) in brain tissues. PCSK9 is a protease closely related to lipid metabolism, but studies have shown that it may be related to the development of AD. LRP1 is abundantly expressed in neuronal cells, and it is an important transporter for the clearance of Aβ. There is now a large amount of literature confirming that PCSK9 can induce the degradation of LRP1. PI3K/AKT is an important signaling pathway in vivo, which plays an important role in apoptosis, and there is now a large amount of literature confirming that LRP1 activates the PI3K/AKT pathway, which has an anti-apoptotic effect. So can PCSK9 affect the PI3K/AKT pathway through LRP1 and thus regulate neuronal apoptosis? This deserves further investigation.The aim of this study was to explore the role of PCSK9 in mediating ox-LDL pro-apoptotic neuronal cell death and its mechanism, and then further elaborate the mechanism of hyperlipidemia leading to neurodegenerative diseases such as AD. MethodsFirstly, PC12 cells were treated with different concentrations of ox-LDL (0, 25, 50, 75 and 100 mg/L) for 24 h. Oil red O staining was used to detect lipid accumulation in PC12 cells, Hoechst33258 staining and flow cytometry to detect apoptosis in PC12 cells, ELISA to detect the content of Aβ secreted by PC12, Western blot to detect expression of SREBP2, PCSK9 and LRP1. Then PC12 cells were treated with 75 mg/L ox-LDL for different times (0, 6, 12, 24, 48 h), and Western blot were performed to detect the expression of SREBP2, PCSK9 and LRP1. Finally, after transfecting 100 nmol/L PCSK9 siRNA into PC12 cells for 48 h, PC12 cells were treated with 75 mg/L ox-LDL for 24 h, Hoechst33258 staining and flow cytometry to detect apoptosis rate of PC12 cells, and Western blot to detect PCSK9, LRP1, PI3K, AKT, P-PI3K , P-AKT, NF-κB, Bcl-2, Bax, Caspase-9 and Caspase-3 expression, and ELISA detected Aβ content secreted by PC12 cells. Resultsox-LDL increased lipid accumulation and promoted apoptosis and Aβ secretion in PC12 cells, as well as increasing the expression of SREBP2 and PCSK9 and decreasing the expression of LRP1 in PC12 cells. pCsk9 siRNA could be inhibited through the PI3K/AKT pathway and the NF-κB-Bcl-2/Bax-Caspase-9/3 pathway to inhibit ox-LDL-induced apoptosis in PC12 cells while increasing Aβ secretion in PC12 cells. Conclusionox-LDL plays a bidirectional regulatory role in ox-LDL-induced apoptosis of PC12 cells by inducing an increase in PCSK9 expression and a decrease in LRP1 expression in PC12 cells, which in turn affects different signaling pathways downstream.
3.Exploration on the Biological Implications of"Earth Deficiency and Wood Depression"Pathogenesis of Hypertension from Intestinal Flora-bile Acid Axis
Meilong SI ; Hua JIN ; Minke LIU ; Yu WANG ; Qiuju ZHANG ; Shuangfang LIU ; Bishi LING ; Shangwen QI
Chinese Journal of Information on Traditional Chinese Medicine 2024;31(3):13-18
There is a bidirectional relationship between intestinal flora and bile acids,and the imbalance of intestinal flora-bile acid axis metabolism is closely related to hypertension.Based on classical TCM literature and clinical practice,this article found that"earth deficiency"is the important pathological basis of hypertension,"wood depression"is the initiating factor of hypertension,and"earth deficiency and wood depression"is the key pathogenesis of hypertension.Combined with the research results of modern medicine and molecular biology,it is considered that the imbalance of intestinal flora and abnormal bile acid metabolism are closely related to the"earth deficiency"and"wood depression"of TCM respectively,and the imbalance of intestinal flora-bile acid axis coincides with the"earth deficiency and wood depression"of TCM in the process of hypertension.It is of great theoretical and practical significance to explore the biological connotation of hypertension"earth deficiency and wood depression"from the perspective of intestinal flora-bile acid axis for guiding TCM to prevent and treat hypertension.
4.Investigation and analysis of the current status of transjugular intrahepatic portosystemic shunt treatment for portal hypertension in China
Haozhuo GUO ; Meng NIU ; Haibo SHAO ; Xinwei HAN ; Jianbo ZHAO ; Junhui SUN ; Zhuting FANG ; Bin XIONG ; Xiaoli ZHU ; Weixin REN ; Min YUAN ; Shiping YU ; Weifu LYU ; Xueqiang ZHANG ; Chunqing ZHANG ; Lei LI ; Xuefeng LUO ; Yusheng SONG ; Yilong MA ; Tong DANG ; Hua XIANG ; Yun JIN ; Hui XUE ; Guiyun JIN ; Xiao LI ; Jiarui LI ; Shi ZHOU ; Changlu YU ; Song HE ; Lei YU ; Hongmei ZU ; Jun MA ; Yanming LEI ; Ke XU ; Xiaolong QI
Chinese Journal of Radiology 2024;58(4):437-443
Objective:To investigate the current situation of the use of transjugular intrahepatic portosystemic shunt (TIPS) for portal hypertension, which should aid the development of TIPS in China.Methods:The China Portal Hypertension Alliance (CHESS) initiated this study that comprehensively investigated the basic situation of TIPS for portal hypertension in China through network research. The survey included the following: the number of surgical cases, main indications, the development of Early-TIPS, TIPS for portal vein cavernous transformation, collateral circulation embolization, intraoperative portal pressure gradient measurement, commonly used stent types, conventional anticoagulation and time, postoperative follow-up, obstacles, and the application of domestic instruments.Results:According to the survey, a total of 13 527 TIPS operations were carried out in 545 hospitals participating in the survey in 2021, and 94.1% of the hospital had the habit of routine follow-up after TIPS. Most hospitals believed that the main indications of TIPS were the control of acute bleeding (42.6%) and the prevention of rebleeding (40.7%). 48.1% of the teams carried out early or priority TIPS, 53.0% of the teams carried out TIPS for the cavernous transformation of the portal vein, and 81.0% chose routine embolization of collateral circulation during operation. Most of them used coils and biological glue as embolic materials, and 78.5% of the team routinely performed intraoperative portal pressure gradient measurements. In selecting TIPS stents, 57.1% of the hospitals woulel choose Viator-specific stents, 57.2% woulel choose conventional anticoagulation after TIPS, and the duration of anticoagulation was between 3-6 months (55.4%). The limitation of TIPS surgery was mainly due to cost (72.3%) and insufficient understanding of doctors in related departments (77.4%). Most teams accepted the domestic instruments used in TIPS (92.7%).Conclusions:This survey shows that TIPS treatment is an essential part of treating portal hypertension in China. The total number of TIPS cases is far from that of patients with portal hypertension. In the future, it is still necessary to popularize TIPS technology and further standardize surgical indications, routine operations, and instrument application.
5.Effect of Zhengan Xifengtang on Blood Pressure and Fecal Microflora of Spontaneously Hypertensive Rats
Shuangfang LIU ; Hua JIN ; Bishi LING ; Shangwen QI ; Meilong SI ; Qiuju ZHANG ; Yu WANG
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(13):76-85
ObjectiveTo observe the effect of Zhengan Xifengtang on blood pressure and fecal microflora of spontaneously hypertensive rats (SHRs). MethodA total of 75 male SHRs aged nine weeks were randomly divided into SHR group, Benazepril group (1.00 mg·kg-1·d-1), high-dose Zhengan Xifengtang group (34.5 g·kg-1·d-1), medium-dose Zhengan Xifengtang group (17.25 g·kg-1·d-1), and low-dose Zhengan Xifengtang group (8.625 g·kg-1·d-1). A total of 15 male Wistar-Kyoto (WKY) rats aged nine weeks were selected as the normal group. The normal group and SHR group were administrated with an equal volume of distilled water for eight weeks. During the administration, the blood pressure of the rats was measured regularly. After the intervention, fresh feces were collected with a sterile frozen storage tube, and 16S amplicon information was collected and analyzed. Plasma, hippocampus, and ileum of rats were collected for ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) detection. ResultZhengan Xifengtang decreased the systolic blood pressure and diastolic blood pressure of SHRs. Compared with the SHR group, Zhengan Xifengtang decreased the diversity of fecal microflora of SHRs. At the phylum level, Zhengan Xifengtang increased the relative abundance of SHR Verrucomicrobia and Actinobacteria and decreased the relative abundance of Synergistetes, Tenericutes, and Candidatus Saccharibacteria. Compared with the SHR group, Zhengan Xifengtang increased the relative abundance of Blautia wexlerae, Fusicatenibacter saccharivorans, and Akkermansia muciniphila and decreased the relative abundance of Clostridium lavalense, Intestinimonas butyriciproducens, Acetatifactor muris, Alloprevotella rava, and Oscillibacter valericigenes. Spearman correlation analysis showed that the systolic blood pressure of rats was negatively correlated with the relative abundance of Ethanoligenens, Aerococcus, Butyrivibrio, Olsenella, Bifidobacterium, Clostridium XIVb, Allobaculum, and Fusicatenibacter and positively correlated with the relative abundance of Alloprevotella. Zhengan Xifengtang increased the contents of plasma, hippocampal 5-hydroxy tryptamine(5-HT), and 5-hydroxyindole acetic acid(5-HIAA) in SHRs and decreased the contents of 5-HT and 5-HIAA in the ileum, and the content of 5-HT in the hippocampus was negatively correlated with that in the ileum. ConclusionZhengan Xifengtang can reduce the blood pressure of SHRs, which may be related to reducing the diversity of SHR microflora, regulating the structure of the microflora, increasing the relative abundance of 5-HT and short-chain fatty acids bacteria, and lowering the relative abundance of pathogenic bacteria related to intestinal inflammation.
6.Full-length transcriptome sequencing and bioinformatics analysis of Polygonatum kingianum
Qi MI ; Yan-li ZHAO ; Ping XU ; Meng-wen YU ; Xuan ZHANG ; Zhen-hua TU ; Chun-hua LI ; Guo-wei ZHENG ; Jia CHEN
Acta Pharmaceutica Sinica 2024;59(6):1864-1872
The purpose of this study was to enrich the genomic information and provide a basis for further development and utilization of
7.Advances in Salmonella -mediated targeted tumor therapy
Zhao-rui LÜ ; Dong-yi LI ; Yu-yang ZHU ; He-qi HUANG ; Hao-nan LI ; Zi-chun HUA
Acta Pharmaceutica Sinica 2024;59(1):17-24
italic>Salmonella has emerged as a promising tumor-targeting strategy in recent years due to its good tumor targeting ability and certain safety. In order to further optimize its therapeutic effect, scientists have tried to modify
8.Progress of traditional Chinese medicine monomers in the treatment of respiratory diseases by intervening nucleotide binding and oligomerization domain-like receptor protein 3 inflammasome
Hua-Yang PAN ; Xu-Ming LUO ; Fu-Qi MA ; Zhen-Hua NI ; Xiong-Biao WANG ; Yu-Hua LIN
The Chinese Journal of Clinical Pharmacology 2024;40(12):1839-1843
Adequate inflammation can effectively eliminate harmful substances and prevent disease as a self-protective measure to prevent further damage to the body,while abnormally activated inflammation is detrimental to the body.Nucleotide binding and oligomerization domain-like receptor protein 3(NLRP3)inflammasome that participates in inflammatory responses are closely related to many physiological and pathological processes and play an important role in the occurrence and development of pulmonary diseases.This article mainly reviewed the activation mechanism and hypothesis of NLRP3 inflammasome,as well as the research on treating respiratory diseases by interfering with NLRP3 inflammasome.
9.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.
10.Reference values of carotid intima-media thickness and arterial stiffness in Chinese adults based on ultrasound radio frequency signal: A nationwide, multicenter study
Changyang XING ; Xiujing XIE ; Yu WU ; Lei XU ; Xiangping GUAN ; Fan LI ; Xiaojun ZHAN ; Hengli YANG ; Jinsong LI ; Qi ZHOU ; Yuming MU ; Qing ZHOU ; Yunchuan DING ; Yingli WANG ; Xiangzhu WANG ; Yu ZHENG ; Xiaofeng SUN ; Hua LI ; Chaoxue ZHANG ; Cheng ZHAO ; Shaodong QIU ; Guozhen YAN ; Hong YANG ; Yinjuan MAO ; Weiwei ZHAN ; Chunyan MA ; Ying GU ; Wu CHEN ; Mingxing XIE ; Tianan JIANG ; Lijun YUAN
Chinese Medical Journal 2024;137(15):1802-1810
Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

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