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.Experimental study on anti-fatigue effect of Polysaccharides of Panax notoginseng
Pan-Pan WEI ; Zi-Jun YAN ; Meng-Yue DENG ; Die XIA ; Yu-Zhen DING ; Lei ZHANG ; Tong CHEN
The Chinese Journal of Clinical Pharmacology 2024;40(1):87-91
Objective To explore the effect of Polysaccharides of Panax notoginseng(PPN)on anti-exercise fatigue in mice.Methods One hundred male KM mice were randomly divided into negative control group,positive control group and experimental-L,-M,-H groups,with 20 cases per group.Experimental-L,-M,-H groups was given 100,200,400 mg·kg-1 PPN,respectively;positive control group was given 200 mg·kg-1 vitamin C;negative control group was given 0.1 mL·10 g-1 0.9%NaCl.Five groups were gavaged once a day for 28 days.After the last administration,the loaded swimming time was measured;after 90 minutes of the unloaded swimming test,the mice were allowed to rest for 30 minutes,the levels of lactic acid(LD),blood urea nitrogen(BUN),glycogen,and malondialdehyde(MDA)were measured,the safety of PPN with organ indices and histopathology.Results LD levels in negative control group,positive control group and experimental-L,-M,-Hgroupswere(4.76±0.84),(2.86±0.34),(3.00±0.69),(2.35±0.65)and(1.39±0.48)mg·kg-1;BUN contents were(13.65±1.25),(12.55±0.91),(12.12±1.24),(11.06±1.30)and(9.85±1.05)mmol·L-1;liver glycogen contents were(3.24±0.56),(11.11±2.16),(5.61±1.41),(6.60±1.49)and(12.05±2.25)mg·g-1;MDA levels were(2.36±0.21),(1.23±0.41),(1.93±0.23),(1.73±0.21)and(1.04±0.18)mg prot·mL-1.Compared with negative control group,the differences of above indexes in the positive control group and experimental-L,-M,-H groups were statistically significant(P<0.05,P<0.01,P<0.001).Conclusion PPN can increase exercise endurance in mice and has an anti-fatigue effect.This study provides a theoretical basis for the application of PPN in the field of anti-fatigue research.
3.Antioxidant activity and organ protection of Panax notoginseng polysaccharide on oxidative damage and aging model mice
Meng-Yue DENG ; Pan-Pan WEI ; Ming LI ; Zi-Jun YAN ; Die XIA ; Yu-Zhen DING ; Lei ZHANG ; Tong CHEN
The Chinese Journal of Clinical Pharmacology 2024;40(6):889-893
Objective To study the antioxidant activity and organ protection of different components of Panax notoginseng polysaccharide(PNPS)in D-galactose-induced oxidative damage aging model mice.Methods KM mice were randomly divided into normal group,model group,vitamin C(VC)group(given 200 mg·kg-1 VC),crude polysaccharide from Panax notoginseng(CPPN)group,neutral polysaccharide from Panax notoginseng(NPPN)group and acidic polysaccharide from Panax notoginseng(APPN-Ⅰ,APPN-Ⅱ,APPN-Ⅲ)group(given 400 mg·kg-1 CPPN,NPPN,APPN-Ⅰ,APPN-Ⅱ,APPN-Ⅲ,respectively).Except for the normal group,oxidative injury aging mouse models were established by intraperitoneal injection of 1 g·kg-1 D-galactose.The mice were sacrificed after continuous administration for 42 days,and serum and liver homogenate were prepared.Malondialdehyde(MDA)was determined by thiobarbituric acid method;superoxide dismutase(SOD)was determined by tetrazole salt method;glutathione peroxidase(GSH-Px)was determined by double antibody sandwich method.Results Serum SOD in the normal group,model group,VC group,CPPN group,NPPN group and APPN-Ⅰ,APPN-Ⅱ,APPN-Ⅲ groups were(15.07±0.69),(12.79±1.51),(15.56±1.01),(13.69±0.96),(14.27±0.64),(14.31±0.99),(14.18±0.79)and(15.85±0.89)U·mL-1;serum GSH-Px were(105.35±4.97),(90.36±4.31),(111.51±7.00),(113.03±8.06),(118.77±5.19),(123.60±8.08),(131.65±3.60)and(149.22±13.32)ng·L-1;serum MDA were(1.72±0.26),(4.16±0.92),(2.26±0.59),(2.82±0.47),(2.46±0.50),(1.98±0.41),(2.39±0.39)and(2.07±0.24)nmol·mL-1;the liver SOD were(234.22±3.84),(205.04±7.28),(234.63±6.37),(214.99±17.66),(234.13±3.63),(234.63±3.44),(233.87±5.63)and(235.42±2.33)U·mgprot-1;liver GSH-Px were(274.27±23.72),(207.00±15.22),(257.68±16.39),(249.79±18.78),(252.62±10.92),(256.25±21.83),(261.20±17.52)and(263.16±17.98)ng·L-1;liver MDA were(35.70±3.52),(49.65±6.32),(36.15±2.48),(39.17±4.29),(37.40±6.19),(35.34±4.06)and(35.90±5.36),(33.31±7.64)nmol·mgprot-1.Compared with the normal group,SOD,GSH-Px in serum and liver of mice in the model group were significantly reduced,and the content of MDA was significantly increased(all P<0.01).After treatment with different components of Panax notoginseng polysaccharide,the oxidative indicators in mice were significantly improved,among which APPN-Ⅲ have the best antioxidant activity,which could significantly increase the activities of SOD,GSH-Px in serum and liver,and reduce the content of MDA(all P<0.01).Conclusion Different components of Panax notoginseng polysaccharide have antioxidant activity and organ protection in vivo,among which APPN-Ⅲ has the best antioxidant activity and has a good organ protection effect.
4.Clinicopathological Features and Long-Term Prognostic Role of Human Epidermal Growth Factor Receptor-2 Low Expression in Chinese Patients with Early Breast Cancer:A Single-Institution Study
Qing Zi KONG ; Qun Li LIU ; Qin De HUANG ; Tong Yu WANG ; Jie Jing LI ; Zheng ZHANG ; Xi Xi WANG ; Ling Chuan LIU ; Di Ya ZHANG ; Kang Jia SHAO ; Min Yi ZHU ; Meng Yi CHEN ; Mei LIU ; Hong Wei ZHAO
Biomedical and Environmental Sciences 2024;37(5):457-470
Objective This study aimed to comprehensively analyze and compare the clinicopathological features and prognosis of Chinese patients with human epidermal growth factor receptor 2(HER2)-low early breast cancer(BC)and HER2-IHC0 BC. Methods Patients diagnosed with HER2-negative BC(N=999)at our institution between January 2011 and December 2015 formed our study population.Clinicopathological characteristics,association between estrogen receptor(ER)expression and HER2-low,and evolution of HER2 immunohistochemical(IHC)score were assessed.Kaplan-Meier method and log-rank test were used to compare the long-term survival outcomes(5-year follow-up)between the HER2-IHC0 and HER2-low groups. Results HER2-low BC group tended to demonstrate high expression of ER and more progesterone receptor(PgR)positivity than HER2-IHC0 BC group(P<0.001).The rate of HER2-low status increased with increasing ER expression levels(Mantel-Haenszel χ2 test,P<0.001,Pearson's R=0.159,P<0.001).Survival analysis revealed a significantly longer overall survival(OS)in HER2-low BC group than in HER2-IHC0 group(P=0.007)in the whole cohort and the hormone receptor(HR)-negative group.There were no significant differences between the two groups in terms of disease-free survival(DFS).The discordance rate of HER2 IHC scores between primary and metastatic sites was 36.84%. Conclusion HER2-low BC may not be regarded as a unique BC group in this population-based study due to similar clinicopathological features and prognostic roles.
5.Spectral Denoising Based on Peak Extraction Combined with Variational Mode Decomposition for Complex Samples
Su-Min LU ; Yue HAO ; Zi-Tong SHI ; Yuan-Yuan CHU ; Yan ZHANG ; Xi-Hui BIAN
Chinese Journal of Analytical Chemistry 2024;52(9):1277-1286
To address the issue of peak loss when applying variational mode decomposition(VMD)to denoise spectra with sharp peaks,in this study,a method for spectral signal denoising of complex samples called peak extraction variational mode decomposition(PE-VMD)was introduced.Firstly,the spectral signal was subjected to a process of denoising utilising the VMD algorithm.Next,the first order derivatives of the spectral signals were calculated to determine the peak center.Subsequently,the second order derivatives of the spectral signal was calculated to extract the sharp peaks with high signal-to-noise ratio(SNR).Finally,the peak intercepted that lose information after VMD denoising were removed,and the remaining spectrum was sequentially connected with the extracted sharp peaks to obtain the final denoised spectrum.The effectiveness of the method was evaluated by one of simulated signals and X-ray diffraction(XRD)spectrum of MnCo-ISAs/CN catalysts.Furthermore,the method was compared with other denoising techniques,including Savitzky-Golay(SG)smoothing,empirical mode decomposition(EMD)and VMD.The efficacy of the denoising process was then assessed by analyzing the spectrograms and signal-to-noise ratio before and after denoising.The results demonstrated that PE-VMD denoising achieved the greatest SNR and effectively preserved the essential information of the spectral signals.Consequently,PE-VMD exhibited superior denoising capability for spectra with sharp peaks.
6.Seroepidemiological survey of Lyme disease in Urumqi City,Xinjiang,China
Li YANG ; Zi-Yi ZHANG ; Tong-Tong SHAO ; Xin-Ting LI ; Rong-Jiong ZHENG ; Shi-Yi WANG ; Yuan-Zhi WANG ; Qin HAO ; Xiao-Bo LU
Chinese Journal of Zoonoses 2024;40(4):334-339
The prevalence of Lyme disease in endogenous populations in Urumqi,Xinjiang was investigated.In total,795 serum samples were collected from residents of three townships in the surrounding area of Urumqi City from 2022 to 2023,which included 383 from Lucaogou Town,145 from Shuixigou Town,and,267 from Tori Township.Serum levels of IgG and IgM antibodies were screened with an enzyme linked immunosorbent assay(ELISA)and confirmed by western blot(WB)analysis.Clinical data of WB-positive indi-viduals were collected and comprehensive analysis was con-ducted for case diagnosis.The chi square test was used for statistical analysis of the results and the P<0.05 was consid-ered statistically significant.In total,110(13.84%)of 795 samples were positive.The positivity rates was higher in females than males[16.26%(73/449)vs.10.69%(37/346),x2=5.076,P=0.024],while there was no significant difference among age groups(x2=2.569,P=0.766).The positivity rates for serum antibodies in Shuixigou Town,Lucaogou Town,and Tuoli Township were 17.98%(48/267),14.48%(21/145),and 10.70%(41/383),respectively,with a significantly higher rate in Tuoli Township than Lucaogou Town(x2=7.041,P=0.008).Of 110 individuals who were initially positive for IgG and IgM antibodies with the ELISA,82(10.31%)were con-firmed positive by WB analysis.In total,20(2.52%)patients were diagnosed with Lyme disease based on clinical manifesta-tions.Lyme disease is epidemic among the population in Urumqi,as the infection rate is higher than the national average.Hence,continued surveillance is recommended for prevention of Lyme disease.
7.The implementation status and policy analysis of the"Dual-channel"management for drugs in national medical insurance negotiations
Bo PENG ; Xiao-Tong JIANG ; Xiao-Juan ZHANG ; Yuan YE ; Xiao-Lin CAO ; Yang LIU ; Ya-Zi LI
Chinese Journal of Health Policy 2024;17(5):9-16
Objective:This study analyzed the provincial policy on the"dual channel"management of drugs,provided suggestions for improving the"dual channel"management models.Methods:From May 10,2021 to April 10,2024,the official websites of the Healthcare Security Administration and the Health Commission of various provinces were searched for policy documents related to the"dual channel"management,and the text data were statistically analyzed.Results:The"dual-channel"management policies of various provinces coexisted with commonalities and differences.Conclusions:It is recommended to refine the access standards of the drug catalog,standardize the setting of the entry threshold of pharmaceutical institutions,scientifically determine the level of medical insurance treatment,and formulate differentiated drug identification and management methods,so as to further weaken the policy restrictive factors.
8.Research progress of inducing ferroptosis of cancer stem cells against colorectal cancer
Li-Na GONG ; Meng-Ling YUAN ; Xue-Ying CHENG ; Chen-Yang XU ; Jun PAN ; Qiu-Tong CHEN ; Ling WANG ; Zi-Li ZHANG ; Mei GUO
Chinese Pharmacological Bulletin 2024;40(6):1030-1034
Cancer stem cell(CSC)are the"seed"cells in the occurrence,development,metastasis and recurrence of colorectal cancer.Targeted killing of CSC provides a new target for anti-colorectal cancer therapy.Ferroptosis is an iron-dependent cell death mode due to the abnormal accumulation of intracellular i-ron ions,which results in the massive reactive oxygen species(ROS)and lipid peroxides,leading to cell death.Studies have shown that cancer stem cells are more enriched in iron ions than non-CSC,which provides a new perspective for targeting ferropto-sis in cancer stem cells against colorectal cancer.This article re-views the research progress of inducing CSC ferroptosis in the treatment of colorectal cancer,such as targeted regulation of SLC7A11 expression in CSC,chelating iron in CSC lysosomes,targeting CSC phenotypic plasticity,reversing CSC iron homeo-stasis,and targeting CSC lipid droplet metabolism induce CSC ferroptosis,which provides new ideas for anti-tumor therapy.
9.Comparison of intracellular uptake and target protein binding characteristics of two BTK inhibitors with different selectivities
Teng ZHANG ; Ting-Fei TAN ; Ying-Li ZHAO ; Gong-Wei HAN ; Zi-Tong XIA ; Han-Bing SHI ; He-Ying LIU ; Jun-Ping WANG ; Quan XIA
Chinese Pharmacological Bulletin 2024;40(10):1899-1905
Aim To investigate the intracellular up-take and target protein binding characteristics of two Bruton's tyrosine kinase inhibitors(BTKi)with differ-ent selectivities to provide further insights into the mechanisms of drug off-target-related bleeding risk.Methods Ibrutinib(non-selective BTKi)and za-nubrutinib(selective BTKi)were used as study drugs.After incubation of MEC-1 cells and human platelets with drugs,the cellular thermal shift assay(CETSA)was combined with Western blot to obtain the melting curve and isothermal curve to analyze the binding char-acteristics of the two drugs with the target protein BTK.After incubation of MEC-1 cells and human platelets with drugs,the concentrations of the two drugs were detected by liquid chromatography-tandem mass spectrometry(LC-MS/MS)to analyze the intracellular uptake of the two drugs.Results CETSA analysis confirmed that zanubrutinib was more selective for the target protein BTK compared to ibrutinib.LC-MS/MS analysis showed that both drugs were uptaken intracel-lularly by MEC-1 cells and platelets in a concentration-dependent manner.Conclusions While BTKi targe-ting BTK to B lymphocytes exerts therapeutic effects,off-target effects on platelets due to differences in their intracellular uptake,and target-binding characteristics may be one of the reasons for the differences in bleed-ing risk across selective BTKi.
10.Exploring the effects of sirolimus on the growth and development of zebrafish embryo models
Zi-Xin ZHANG ; Tong QIU ; Jiang-Yuan ZHOU ; Xue-Peng ZHANG ; Xue GONG ; Kai-Ying YANG ; Yu-Ru LAN ; Si-Yuan CHEN ; Yi JI
Chinese Pharmacological Bulletin 2024;40(12):2368-2374
Aim To explore the effects of sirolimus on the growth and development of motor,vascular,nerv-ous,and immune systems through zebrafish models.Methods After 3 hours of fertilization of zebrafish embryos,different concentrations of sirolimus were add-ed to the growth environment,and the growth and de-velopment of the embryos was recorded.Transgenic ze-brafish models labeled with blood vessels,nerves or im-mune cells were used to compare the drug effects on the growth and development of those systems.Results At the concentration of 0.5 μmol·L-1,the hatching rate and the body length(P<0.01)were significantly smaller than those of the control group,and movement was also significantly slowed down.Meanwhile,the length of axons of the nervous system,the development of intersegmental vessels,and the growth of immune cells were significantly delayed by drug treatment.But when the concentration was below 0.1 μmol·L-1,there was no statistically difference between the control group and the sirolimus group.Conclusions When the concentration of sirolimus exceeds a certain level,it can significantly slow down the growth and development of movement,blood vessels,nervous system and im-mune system of zebrafish.Therefore,in clinical prac-tice,it is important to monitor the blood concentration of sirolimus in children on time.

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