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.Norepinephrine triggers glutamatergic long-term potentiation in hypothalamic paraventricular nucleus magnocellular neuroendocrine cells through postsynaptic ββ1-AR/PKA signaling pathway in vitro in rats
Jing-Ri JIN ; Zhao-Yi ZHANG ; Chun-Ping CHU ; Yu-Zi LI ; De-Lai QIU
The Korean Journal of Physiology and Pharmacology 2024;28(6):569-576
Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.
3.Mechanism of icariin inhibiting the proliferation of human prostate cancer PC-3 cells:An exploration based on cell metabolomics
Tao WANG ; Wei WANG ; Wen-Jun XIONG ; Zi-Jing ZHANG ; Fei WANG ; Yao-Hui PENG ; Yan CHEN ; Hai-Ping ZENG ; Li-Jie LUO
National Journal of Andrology 2024;30(11):963-973
Objective:To study the mechanism of icariin inhibiting the proliferation of human PCa PC-3 cells based on cell metabolomics technology.Methods:We determined the proliferation activity of human PC-3 cells by methyl thiazolyl tetrazolium(MTT)assay,and compared the proliferation of the PC-3 cells among the control,5-fluorouracil and icariin intervention groups.Using the Bligh Dyer method,we extracted endogenous metabolites from the cells,analyzed the metabolic profile by ultra-high pressure liquid chromatography tandem quadrupole time-of-flight mass spectrometry,identified the differential metabolites by principal component anal-ysis and orthogonal partial least-squares discrimination analysis,and enriched the metabolic pathways based on the MetaboAnalyst data-base.Results:Icariin significantly inhibited the proliferation of human PCa PC-3 cells.A total of 89 differential metabolites were i-dentified,mainly including amino acids,phosphatidylcholine,phosphatidylethanolamine,lysophosphatidylcholine,and lysophosphati-dylethanolamine,all with the tendency to return to the normal level after icariin intervention.Icariin significantly downregulated the metabolic levels of the glycerophospholipid metabolites phosphatidylcholine,phosphatidylethanolamine,lysophosphatidylcholine and ly-sophosphatidylethanolamine,and upregulated those of amino acid metabolites tryptophan,leucine,and proline in the PC-3 cells.Conclusion:Icariin inhibits the proliferation of human PCa PC-3 cells,which may be closely related to its regulatory effect on lipid metabolism(glycerophospholipid metabolism)and amino acid metabolism.
4.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.
5.PI3K/Akt pathway-based investigation of total Astragalus saponins on sarcopenia in a rat model of type 2 diabetes mellitus
Lei-Lei MA ; Ji-An LI ; Wen-Xuan XU ; Jing-Ya WANG ; Zhao-Yang TIAN ; Jia-Yu LI ; Ru-Jie HAN ; Xiao-Jin LA ; Chun-Yu TIAN ; Hong CHANG ; Zi-Yang DAI ; Bi-Wei ZHANG
Chinese Traditional Patent Medicine 2024;46(11):3612-3619
AIM To investigate the effects of total Astragalus saponins on the improvement of sarcopenia in a rat model of type 2 diabetes mellitus(T2DM).METHODS The rats were divided into the normal group for a normal feeding and the model group for the feeding of high-sugar and high-fat diet combined with intraperitoneal injection of STZ to establish a T2DM model.The successful model rats were randomly divided into the model group,the metformin group(0.2 g/kg)and the total Astragalus saponins group(80 mg/kg),and given corresponding doses of drugs by gavage.After 12 weeks administration,the rats had their FBG,postprandial blood glucose(PG2h)and wet weight of skeletal muscle measured;their serum levels of INS,C-peptide(C-P),IGF-1,TNF-α and IL-1β detected by ELISA;their morphological changes of skeletal muscle observed by HE staining;their protein expressions of PI3K,p-Akt,mTOR,S6K1,FoxO1 and Murf1 in skeletal muscle detected by Western blot;and their mRNA expressions of Pi3k,Akt and mtor in skeletal muscle detected by RT-qPCR method.RESULTS Compared with the model group,the total Astragalus saponins group displayed decreased levels of FBG,PG2h,OGTT-AUC,HOMA-IR,TNF-α and IL-1β(P<0.01);increased levels of INS,C-P,IGF-1 and wet weight of skeletal muscle(P<0.05,P<0.01);improved skeletal muscle atrophy and increased protein expressions of PI3K,p-Akt,mTOR and S6K1 in skeletal muscle(P<0.05,P<0.01);decreased protein expressions of FoxO1 and Murf1(P<0.05,P<0.01);and increased mRNA expressions of Pi3k,Akt and mtor(P<0.01).CONCLUSION The improvement effects of total Astragalus saponins on sarcopenia in T2DM rats may be associated with the regulation of PI3K/Akt/mTOR and PI3K/Akt/FoxO1 pathways.
6.Norepinephrine triggers glutamatergic long-term potentiation in hypothalamic paraventricular nucleus magnocellular neuroendocrine cells through postsynaptic ββ1-AR/PKA signaling pathway in vitro in rats
Jing-Ri JIN ; Zhao-Yi ZHANG ; Chun-Ping CHU ; Yu-Zi LI ; De-Lai QIU
The Korean Journal of Physiology and Pharmacology 2024;28(6):569-576
Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.
7.Norepinephrine triggers glutamatergic long-term potentiation in hypothalamic paraventricular nucleus magnocellular neuroendocrine cells through postsynaptic ββ1-AR/PKA signaling pathway in vitro in rats
Jing-Ri JIN ; Zhao-Yi ZHANG ; Chun-Ping CHU ; Yu-Zi LI ; De-Lai QIU
The Korean Journal of Physiology and Pharmacology 2024;28(6):569-576
Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.
8.Effect of delayed cleaning on cleaning and disinfection quality of gastro-scopes
Liu-Ji CHEN ; Jing ZHEN ; Yang-Yang ZHANG ; Zi-Yi HUANG ; Xian-Huang LI ; Xi HUANG ; Jiu-Hong MA
Chinese Journal of Infection Control 2024;23(6):725-730
Objective To evaluate the effect of delayed cleaning on the cleaning and disinfection quality of gastro-scopes after pre-treatment with different solutions.Methods According to the factorial design table,combination of the pre-treatment cleaning solutions(factor A)(including multi-enzyme cleaning solution[A1],clean water[A2])and delayed cleaning durations(factor B)(including 0 minutes after pre-treatment[B1],30 minutes after pre-treat-ment[B2],1 hour after pre-treatment[B3],and 3 hours after pre-treatment[B4])yielded eight groups(A1B1,A1B2,A1B3,A1B4,A2B1,A2B2,A2B3,A2B4).According to the usage order of gastroscopes,96 gastroscopes used in the digestive endoscopy center of a tertiary first-class hospital from May to September,2023 were randomly assigned to each group by random number table method,with 12 gastroscopes in each group.Specimens were taken at four time points:after pre-treatment,before cleaning,after cleaning,and after disinfection.Due to instant clea-ning,no specimen before cleaning were taken from A1B1 and A2B1 groups,thus only 3 specimens were taken from these two groups each.Four specimens were taken from gastroscopes in the rest groups,resulting in 360 specimens in total.The internal condition of the biopsy cavity was observed through a cavity detector during each delayed cleaning period after pre-treatment,and specimens were taken at the subsequent reprocessing processes of the gas-troscopes.The microbial conditions of the gastroscopes after pre-treatment,before cleaning,after cleaning,and af-ter disinfection were compared.Results After pre-treatment with multi-enzyme cleaning solution and clean water,there was no statistically significant difference in microbiological detection result(P>0.05).The biopsy cavity re-mained moist during the delayed cleaning period.There was no statistically significant difference in the microbial de-tection results of factors A and B before and after delayed cleaning as well as after disinfection(all P>0.05).There was no interaction effect between factor A and B.The distribution of bacterial colonies and disinfection qualified rate of gastroscopes after pre-treatment with two cleaning solutions were also not statistically different(both P>0.05).Conclusion Delayed cleaning for 30 minutes,1 hour,and 3 hours after pre-treatment does not affect the cleaning and disinfection quality of gastroscopes.When clinical demand is urgent,immediate cleaning should be carried out.However,a certain buffering time(no longer than 3 hours)before cleaning is acceptable,when cleaning and disin-fection workload is heavy and timely cleaning cannot be carried out.
9.Changing trend and multivariate analysis of prevalence rates of healthcare-associated infection in a tertiary hospital for 10 years
Zi-Quan ZHOU ; Jin-Ai QIN ; Juan HUANG ; Yong-Kang YE ; Qun-Xiu GUO ; Lan-Lan LI ; Jing-Jing YA ; Ying-Hua ZHANG
Chinese Journal of Infection Control 2024;23(9):1135-1141
Objective To describe the changing trend and related factors of prevalence rates of healthcare-associa-ted infection(HAI)in a tertiary hospital in the past 10 years,and analyze the influencing factors for HAI.Methods A cross-sectional survey on HAI was conducted for 10 consecutive years from 2013 to 2022(one day was selected as the survey day each year),data were collected.The distribution and related factors of prevalence rates of HAI were analyzed by trend-x2 test and Pearson correlation coefficient.Multivariate logistic regression and multilayer percep-tron(MLP)models were constructed to analyze the independent effect and significance of factors.Results From 2013 to 2022,the prevalence rates of HAI ranged from 4.66%to 8.07%in this hospital,showing a linear upward trend.The proportions of ICU patients and utilization rate of central venous catheters within 2 days before the sur-vey showed linear upward trends,while the proportion of patients with urinary catheters within 2 days before the survey and proportion of patients undergoing surgery within 30 days before the survey decreased.The MLP model revealed that the top 3 important factors for HAI were length of hospital stay>10 days,admission in ICU,and in-dwelling central venous catheters within 2 days before the survey.Multivariate logistic regression model indicated that length of hospital stay>10 days,indwelling central venous catheters or urinary catheters within 2 days before the survey,surgery within 30 days before the survey,and admission in ICU were independent influencing factors for HAI.Conclusion The incidence of HAI in this hospital presents a linear increase in recent 10 years,the causes should be further analyzed and the direction of intervention should be determined through targeted surveillance.Adopting trend test statistical analysis method,logistic regression,MLP multi-factor model can further explore the data value of HAI prevalence survey.
10.Chinese expert consensus on targeted and immunotherapy combined with concurrent chemoradiotherapy in the treatment of locally advanced cervical cancer
Ping JIANG ; Zi LIU ; Lichun WEI ; Yunyan ZHANG ; Fengju ZHAO ; Xiangkun YUAN ; Yipeng SONG ; Jing BAI ; Xiaofan LI ; Baosheng SUN ; Lijuan ZOU ; Sha LI ; Yuhua GAO ; Yanhong ZHUO ; Song GAO ; Qin XU ; Xiaohong ZHOU ; Hong ZHU ; Junjie WANG
Chinese Journal of Radiation Oncology 2024;33(10):893-901
Concurrent chemoradiotherapy (CCRT) refers to the simultaneous treatment of chemotherapy and radiotherapy, and the effect of radiotherapy is enhanced with low-dose chemotherapy, which can reduce tumor recurrence and metastasis and improve clinical prognosis of patients. At present, the main factors for the increase of radiosensitivity of concurrent chemotherapy is that concurrent chemotherapy prevents the repair of tumor cells, and chemotherapy and radiotherapy act on different cell cycles and have synergistic effects. However, even for patients with locally advanced cervical cancer (LACC) who have undergone CCRT, the 5-year survival rate is only 60%, which is still not ideal. In order to improve the efficacy, researchers have conducted a series of exploratory studies, which consist of the combination of targeted drugs and immunodrugs, and neoadjuvant regimens before CCRT, etc. Although targeted or immunologic drugs are effective treatment of LACC, in view of the lack of large-scale evidence-based medical evidence, multi-center prospective and randomized phase III clinical trials and high-level articles are needed to improve the level of evidence-based medicine. This consensus summarizes several key evidence-based medical studies published recently, especially the clinical research progress in targeted and immunological therapies, providing reference for domestic peers.

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