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.Quality contol of Bupleurum chinense
Jing-Bo YU ; Yue HAN ; Qi-Di AI ; Yang SUN ; Zi-Yang ZHOU ; Sai-Hu LIU ; Zi-Hao ZHANG ; Hui SHU ; Yu-Hong WANG
Chinese Traditional Patent Medicine 2024;46(7):2129-2133
AIM To control the quality of Bupleurum chinense DC.METHODS The analysis was performed on a 35℃ thermostatic Venusil XBP C18 column(250 mm×4.6 mm,5 μm),with the mobile phase comprising of acetonitrile-water flowing at 1.0 mL/min,and the detection wavelength was set at 210 nm.The HPLC fingerprints were established,after which the contents of saikosaponin A,saikosaponin B2,saikosaponin C,saikosaponin D,saikosaponin E,saikosaponin F and 6″-O-acetylsaikosaponin A were determined,and principal component analysis was made.RESULTS There were thirteen common peaks in the fingerprints for twelve batches of medicinal materials with the similarities of 0.970-0.995.Seven constituents showed good linear relationships within their own ranges(R2≥0.999 8),whose average recoveries were 90.75%-100.91% with the RSDs of 1.6%-4.0% .Various constituents demonstrated similar contents in medicinal materials originated in Inner Mongolia and Shanxi.CONCLUSION This precise,accurate and stable method can be used for the quality evaluation of B.chinense.
3.Advances of ceftazidime/avibactam in the treatment of carbapenem-resis-tant Klebsiella pneumoniae infection
Yuan-Qi ZHAO ; Ming-Jing CHENG ; Miao-Miao XIONG ; Min XIAO ; Xiu-Yu CUI ; Zi-Jian ZHOU ; Yi-Wei YU ; Wei-Dong ZHAO
Chinese Journal of Infection Control 2024;23(8):1047-1052
In recent years,the prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKP)infection has become a global public health issue.Ceftazidime/avibactam(CAZ/AVI)has been approved as a novel antimicrobial agent for the treatment of healthcare-associated pneumonia/ventilator-associated pneumonia,bloodstream infection,infection after kidney transplantation,and severe infection combined with liver cirrhosis.However,the use of CAZ/AVI has also led to the emergence of drug-resistant strains.The major mechanisms of drug-resistance include over-expression of blaKPC gene,mutation of β-lactamase and amino acids at key sites,changes in cell permeability caused by loss of membrane porin,and over-expression of efflux pump.This article reviews the research progress of CAZ/AVI in the treatment of CRKP infection,providing reference for clinical diagnosis and treatment.
4. Establishment and biological characterization of drug-resistant cells and identification of multidrug resistance in small-cell lung cancer
Yong-Qing HAN ; Zheng-Yuan WANG ; Xiu-Fen DAI ; Zi-Ran WANG ; Jing LI ; Xin QI ; Jing LI
Chinese Pharmacological Bulletin 2024;40(2):279-284
Aim To establish NCI-H446/EP for small cell lung cancer resistant cells resistant to cisplatin and etoposide, and to evaluate their biological characteristics and multidrug resistance. Methods Nude mice were subcutaneously inoculated with NCI-H446 cells of SCLC to construct an in vivo model of xenograft tumor, and were given first-line EP regimen treatment for SCLC, inducing drug resistance in vivo, and stripping tumor tissue in vitro culture to obtain drug-resistant cells. The resistance coefficient, cell doubling time, cell cycle distribution, expression of multidrug resistance gene (MDR1), and drug resistance-related protein were detected in vitro, and the drug resistance to cisplatin and etoposide in vivo were verified. Results Mice with NCI-H446 tumors acquired resistance after eight weeks' EP regimen treatment, and the drug-resistant cell line NCI-H446/EP was obtained by isolation and culture in vitro. The resistance factors of this cell line to cisplatin, etoposide, SN38 and doxorubicin were 12.01, 18.36, 65.4 and 10.12, respectively. Compared with parental cells, the proportion of NCIH446/EP cells in Q
5.Research on species identification of commercial medicinal and food homology scented herbal tea
Jing SUN ; Zi-yi HUANG ; Si-qi LI ; Yu-fang LI ; Yan HU ; Shi-wen GUO ; Ge HU ; Chuan-pu SHEN ; Fu-rong YANG ; Yu-lin LIN ; Tian-yi XIN ; Xiang-dong PU
Acta Pharmaceutica Sinica 2024;59(9):2612-2624
The adulteration and counterfeiting of herbal ingredients in medicinal and food homology (MFH) have a serious impact on the quality of herbal materials, thereby endangering human health. Compared to pharmaceutical drugs, health products derived from traditional Chinese medicine (TCM) are more easily accessible and closely integrated into consumers' daily life. However, the authentication of the authenticity of TCM ingredients in MFH has not received sufficient attention. The lack of clear standards emphasizes the necessity of conducting systematic research in this area. This study utilized DNA barcoding technology, combining ITS2,
6.Synthesis and anti-tumor activity of pyrazole pyrimidine PI3Kγ /δ inhibitors
Mao-qing DENG ; Feng-ming ZOU ; Zi-ping QI ; Chun WANG ; Kai-li LONG ; Qing-wang LIU ; Ao-li WANG ; Jing LIU ; Xiao-fei LIANG
Acta Pharmaceutica Sinica 2024;59(7):2041-2052
PI3K
7.Study on the changes of skeletal muscle index during chemoradiotherapy for patients with cervical cancer and its correlation with prognosis
Fan ZHOU ; Jin-Feng BAO ; Hui LU ; Mei-Qing DING ; Li-Ping DENG ; Zi YIN ; Zi-Qi CHEN ; Li-Jing ZHU
Parenteral & Enteral Nutrition 2024;31(4):211-219
Objective:To study the changes in skeletal muscle and serum nutritional indicators during concurrent chemoradiotherapy in cervical cancer patients,and to evaluate their correlation with short-term efficacy and long-term prognosis. Methods:A retrospective analysis was conducted on 114 patients with cervical cancer who underwent radical concurrent chemoradiotherapy in the Department of Oncology,Nanjing Drum Tower Hospital from February 2019 to February 2023. All patients underwent a treatment regimen comprising external beam radiation (EBRT),internal radiation,and concurrent chemotherapy. Serum nutritional data of the patients were collected before radiotherapy,one week,two weeks and five weeks after the onset of radiotherapy. CT images of the patients at the time of simulation and about five weeks after the onset of radiotherapy were imported into the Pinnacle 39.10 planning system,and the skeletal muscle index (SMI) of the third lumbar vertebra (L3) were calculated for each patients. The changes of the serum nutritional indicators of the patients prior to and post EBRT were analyzed statistically. The patients are categorized into two groups according to the baseline SMI:a sarcopenic group consisting of 35 cases and a non-sarcopenic group comprising 79 cases. The therapeutic outcomes between the two groups were compared,and logistic analysis of the relevant factors affecting the occurrence of sarcopenia during radiotherapy was conducted. The survival curves were drawn using Kaplan-Meier method and disease-free survival (DFS) between the two groups was compared using Log Rank test. We used Cox univariate and multivariate regression analysis to identify prognostic factors related to DFS. Results:The serum nutritional indicators of the patient at one week,two weeks,and five weeks after the beginning of EBRT were significantly lower than those before radiotherapy (P<0.05). The SMI from the CT images of simulation at five weeks after the onset of radiotherapy was significantly lower than that before radiotherapy (P<0.001). There was a significant correlation between hemoglobin levels prior to radiotherapy and incidence of sarcopenia during radiotherapy (P=0.046). There was no significant difference in efficacy between the two groups at the end of EBRT (P>0.05). At the end of radiotherapy,the complete response (CR) rate of the non-sarcopenia group was significantly higher than that of the sarcopenia group (P=0.040). However,the objective response rate (ORR) and disease control rate (DCR) of both groups at the end of radiotherapy were 100%. The 2-year DFS of the sarcopenia group and the non-sarcopenia group were 66.7% and 85.5%,respectively,and the difference was statistically significant (P=0.016). Only four patients died during the 2-year follow-up,so OS was not reached. Baseline SMI,serum squamous cell antigen levels prior to radiotherapy,and degree of bone marrow suppression were three independent prognostic factors affecting DFS in the patients. Conclusion:Cervical cancer patients experience significant nutritional loss during chemoradiotherapy,and baseline SMI is significantly correlated with short-term efficacy and long-term prognosis and can serve as a predictive marker for patients with cervical cancer receiving chemoradiotherapy.
8.Construction of folate receptors and mitochondria targeting celastrol-loaded PAMAM nano-drug delivery system and its in vitro anti-inflammatory effect
Zi-qi JING ; Xue WANG ; Tian-yue YAN ; Yu-jie ZHANG ; Peng-kai MA
Acta Pharmaceutica Sinica 2023;58(3):550-559
Pro-inflammatory macrophages play key regulatory role in the occurrence and development of rheumatoid arthritis (RA). In this study, we constructed a celastrol (Cel)-loaded polyamide-amine dendrimer (PAMAM) drug delivery system, which could target folate receptor and mitochondria. It could target inflammatory macrophages and realize chemo-photothermal synergistic therapy. Using PAMAM as the nano-carrier, folate receptor-targeting group folic acid (FA) and mitochondria-targeting group IR808 (also known as the photothermal agent) were conjugated with PAMAM through amide reaction, and then complexed with anti-inflammatory drug Cel to prepare the FA-PAMAM-IR808/Cel nanocomplex.
9.Interferon-α mediating the functional damage of CD56dimCD57+natural killer cells in peripheral blood of systemic lupus erythematosuss.
Xiang Ge ZHAO ; Jia Qing LIU ; Hui Na HUANG ; Zhi Min LU ; Zi Ran BAI ; Xia LI ; Jing Jing QI
Journal of Peking University(Health Sciences) 2023;55(6):975-981
OBJECTIVE:
To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56dimCD57+ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism.
METHODS:
A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56dimCD57+ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H2O2), and treated without H2O2 as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56dimCD57+ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56dimCD57+ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI.
RESULTS:
Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56dimCD57+ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H2O2 treatment significantly down-regulated the PRF expression levels of CD56dimCD57+ NK cells in a dose-dependent manner, the 20 μmol/L H2O2 PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H2O2 PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H2O2 PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56dimCD57+ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56dimCD57+ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation.
CONCLUSION
High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56dimCD57+ NK killing function.
Humans
;
Interferon-alpha/metabolism*
;
Perforin/metabolism*
;
Leukocytes, Mononuclear/metabolism*
;
Hydrogen Peroxide/metabolism*
;
Interferon-gamma/metabolism*
;
CD56 Antigen/metabolism*
;
Killer Cells, Natural/metabolism*
;
Lupus Erythematosus, Systemic
10.Predictive validation of existing bleeding and thromboembolic scores in elderly patients with comorbid atrial fibrillation and acute coronary syndrome.
Hong-Hong ZHANG ; Qi LIU ; Hai-Jing ZHAO ; Ya-Ni YU ; Liu-Yang TIAN ; Ying-Yue ZHANG ; Zi-Hao FU ; Li ZHENG ; Yue ZHU ; Yu-Han MA ; Shuang LI ; Yang-Yang MA ; Yu-Qi LIU
Journal of Geriatric Cardiology 2023;20(5):330-340
BACKGROUND:
The validation of various risk scores in elderly patients with comorbid atrial fibrillation (AF) and acute coronary syndrome (ACS) has not been reported. The present study compared the predictive performance of existing risk scores in these patients.
METHODS:
A total of 1252 elderly patients with AF and ACS comorbidities (≥ 65 years old) were consecutively enrolled from January 2015 to December 2019. All patients were followed up for one year. The predictive performance of risk scores in predicting bleeding and thromboembolic events was calculated and compared.
RESULTS:
During the 1-year follow-up, 183 (14.6%) patients had thromboembolic events, 198 (15.8%) patients had BARC class ≥ 2 bleeding events, and 61 (4.9%) patients had BARC class ≥ 3 bleeding events. For the BARC class ≥ 3 bleeding events, discrimination of the existing risk scores was low to moderate, PRECISE-DAPT (C-statistic: 0.638, 95% CI: 0.611-0.665), ATRIA (C-statistic: 0.615, 95% CI: 0.587-0.642), PARIS-MB (C-statistic: 0.612, 95% CI: 0.584-0.639), HAS-BLED (C-statistic: 0.597, 95% CI: 0.569-0.624) and CRUSADE (C-statistic: 0.595, 95% CI: 0.567-0.622). However, the calibration was good. PRECISE-DAPT showed a higher integrated discrimination improvement (IDI) than PARIS-MB, HAS-BLED, ATRIA, and CRUSADE (P < 0.05) and the best decision curve analysis (DCA). For thromboembolic events, the discrimination of GRACE (C-statistic: 0.636, 95% CI: 0.608-0.662) was higher than CHA2DS2-VASc (C-statistic: 0.612, 95% CI: 0.584-0.639), OPT-CAD (C-statistic: 0.602, 95% CI: 0.574-0.629) and PARIS-CTE (C-statistic: 0.595, 95% CI: 0.567-0.622). The calibration was good. Compared to OPT-CAD and PARIS-CTE, the IDI of the GRACE score slightly improved (P < 0.05). However, NRI analysis showed no significant difference. DCA showed that the clinical practicability of thromboembolic risk scores was similar.
CONCLUSIONS
The discrimination and calibration of existing risk scores in predicting 1-year thromboembolic and bleeding events were unsatisfactory in elderly patients with comorbid AF and ACS. PRECISE-DAPT showed higher IDI and DCA than other risk scores in predicting BARC class ≥ 3 bleeding events. The GRACE score showed a slight advantage in predicting thrombotic events.

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