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.Collection, storage and utilization of lung transplant tissue samples
Yixing LI ; Xue SHI ; Hongyi WANG ; Runyi TAO ; Ye SUN ; Ailing SU ; Liyan TONG ; Jinteng FENG ; Yanpeng ZHANG ; Shuo LI ; Yawen WANG ; Guangjian ZHANG
Organ Transplantation 2025;16(1):147-155
After continuous development and improvement, lung transplantation has become the preferred means to treat a variety of benign end-stage lung diseases. However, the field of lung transplantation still faces many challenges, including shortage of donor resources, preservation and maintenance of donor lungs, and postoperative complications. Lung tissue samples removed after lung transplantation are excellent clinical resources for the study of benign end-stage lung disease and perioperative complications of lung transplantation. However, at present, the collection, storage and utilization of tissue samples after lung transplantation are limited to a single study, and unified technical specifications have not been formed. Based on the construction plan of the biobank for lung transplantation in the First Affiliated Hospital of Xi'an Jiaotong University, this study reviewed the practical experience in the collection, storage and utilization of lung transplant tissue samples in the aspects of ethical review, staffing, collection process, storage method, quality control and efficient utilization, in order to provide references for lung transplant related research.
3.Exploration of Pulmonary Vascular Remodeling Improvement in Rats at Different Stages of Chronic Obstructive Pulmonary Disease by Qibai Pingfei Capsules Based on TLR4/NF-κB Signaling Pathway
Lu ZHANG ; Li FANG ; Shuyu XU ; Xue LIANG ; Jie ZHU ; Xiangli TONG ; Zegeng LI
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(9):48-56
ObjectiveTo investigate the improvement effect of Qibai Pingfei capsules on pulmonary vascular remodeling in rats at different stages of chronic obstructive pulmonary disease (COPD) and to analyze its possible mechanism of action. MethodsMale Sprague-Dawley (SD) rats were randomly divided into a normal group, an early COPD model group, an advanced COPD model group, an early-intervention high-dose group, a late-intervention high-dose group, an early-intervention low-dose group, a late-intervention low-dose group, an early-intervention pyrrolidine dithiocarbamate (PDTC) group, and a late-intervention PDTC group, with 15 rats in each group. A rat model of early COPD was constructed by using cigarette smoke combined with airway infusion using lipopolysaccharide(LPS), and a rat model of advanced COPD was constructed by using airway infusion with LPS, cigarette smoke, and hypoxia. All groups except the normal group were given LPS airway drops on days 1 and 14 of the experiment, smoked for 1 h per day, and administered the drug once a day for 40 weeks from day 15 onward. In the high- and low-dose groups, rats were given 1 g·kg-1 and 250 mg·kg-1 Qibai Pingfei capsules, respectively by gavage, and in PDTC groups, rats were given 100 mg·kg-1 of PDTC by intraperitoneal injection. The advanced COPD model group underwent 6 h of hypoxia per day in weeks 5-6. Lung function and mean pulmonary artery pressure were tested in rats. Morphologic changes in lung tissues were detected by hematoxylin-eosin(HE)staining. Collagen deposition in lung tissues was examined by Masson staining, and the levels of inflammatory factors including interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α)in lung tissues were detected by enzyme-linked immunosorbent assay (ELISA). The number of inflammatory cells in the alveolar lavage fluid of rats in each group was detected by Giemsa staining, and the protein expression of Toll-like receptor 4(TLR4), myeloid differentiation factor 88(MyD88), nuclear factor-κB(NF-κB), TNF-α, vascular endothelial-cadherin(VE-cadherin), α-smooth muscle actin(α-SMA), and platelet endothelial cell adhesion molecule-1(CD31) was detected by Western blot in the lung tissues of rats. ResultsCompared with the normal group, the model group showed significantly decreased forced expiratory volume in 0.3 s (FEV0.3), forced vital capacity (FVC), and FEV0.3/FVC ratio related to lung function (P<0.05), thickening of pulmonary vasculature, increased collagen deposition in the lungs, and enhanced mean pulmonary arterial pressure and expression levels of IL-6, IL-1β, and TNF-α (P<0.05). Additionally, the model group also exhibited increased numbers of macrophages, lymphocytes, and neutrophils (P<0.05), significantly higher protein expression of TLR4, MyD88, NF-κB, TNF-α, and α-SMA (P<0.05), and significantly lower protein expression of VE-cadherin and CD31 (P<0.05). Lung function was significantly improved in the Qibai Pingfei capsules groups compared with the model group (P<0.05), with mean pulmonary arterial pressure reduced and pulmonary vascular thickening and collagen deposition in the lungs ameliorated. The Qibai Pingfei capsules groups also showed reduced expression levels of IL-6, IL-1β, and TNF-α (P<0.05) and decreased numbers of macrophages, lymphocytes, and neutrophils (P<0.05), as well as reduced protein expression of TLR4, MyD88, NF-κB, TNF-α, and α-SMA (P<0.05) and elevated protein expression of VE-cadherin and CD31 (P<0.05) in rat lung tissues. ConclusionQibai Pingfei capsules inhibits inflammatory response and endothelial-to-mesenchymal transition probably by regulating the TLR4/NF-κB signaling pathway, thus improving pulmonary vascular remodeling in COPD model rats and showing therapeutic effects in the early stage of COPD.
4.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.
5.Study on detection of bacterial endotoxin by micro kinetic chromogenic method
Chen-Xue ZHANG ; Tong CAI ; Chen CHEN ; Xiao-Yan ZHAO ; Yu-Sheng PEI
Chinese Pharmacological Bulletin 2024;40(7):1392-1398
Aim To determine whether the micro kinetic chro-mogenic method can meet the requirements of Chinese Pharma-copoeia,as a supplement to the existing bacterial endotoxin test method.Methods Using micro kinetic chromogenic horseshoe crab reagent,the sample volume per well was 25 μL,the detec-tion wavelength was 405 nm,the preset OD value was 0.05,and the detection was carried out by half-well enzyme plate.In accordance with the provisions of"9101 Guiding Principles for Validation of Drug Quality Analysis Methods"in the fourth part of the 2020 edition of the People's Republic of China Pharmaco-poeia,the methodological verification of 7 items of specificity,accuracy,precision,limit of quantification,linearity,range and durability was carried out according to the specific requirements of the"quantitative"item in the"Determination of Impurities".The variety suitability study was conducted on 74 batches of samples from 48 drug varieties,and 143 batches of samples from 76 drug varieties(including 133 batches of negative samples and 10 batches of positive samples)were tested daily,and the re-sults were compared with the results of traditional color rendering method.Results The method of microdynamic color develop-ment met the requirements of the Pharmacopoeia of the People's Republic of China for quantitative methods.The results of varie-tal applicability and consistency comparison showed that the mi-crodynamic color development method had better equivalence compared with the traditional color development method.Con-clusion The micro kinetic chromogenic method can be promo-ted as a supplementary alternative to the existing bacterial endo-toxin methods.
6.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.
7.AI-HIP system for prosthesis size,global femoral offset and osteotomy in total hip arthroplasty
Guo-Yuan SUN ; Yan-Kun JIANG ; Tong LI ; Xue-Feng CONG ; Cheng HUANG ; Ran DING ; Wei-Guo WANG ; Qi-Dong ZHANG
China Journal of Orthopaedics and Traumatology 2024;37(9):848-854
Objective To explore planning effect of AI-HIP assisted surgical planning system in primary unilateral total hip arthroplasty(THA)and its influence on clinical outcomes.Methods A retrospective analysis was conducted on clinical data of 36 patients who underwent their first unilateral THA from March 2022 to November 2022 and continuously used AI-HIP system(AI-HIP group),including 16 males and 20 females,aged from 43 to 81 years old with an average of(62.2±10.9)years old.According to the matching principle,36 patients who were planned by the traditional template method at the same period were selected as the control group,including 16 males and 20 females,aged from 40 to 80 years old with an average of(60.9±12.1)years old.The accuracy between two groups of prostheses were compared,as well as the combined eccentricity difference between preoperative planning and postoperative practice,lower limb length difference,osteotomy height from the upper edge of the lesser trochanter and top shoulder distance to evaluate planning effect.Harris score and visual analogue scale(VAS)were used to evaluate clinical efficacy.Results Both groups were followed up for 12 to 18 months with an average of(14.5±2.1)months.The complete accuracy and approximate accuracy of acetabular cup and femoral stalk prosthesis in AI-HIP group were 72.2%,100%,58.3%,88.9%,respectively,which were better than 44.4%,83.3%,33.3%,66.7%in control group(P<0.05).There was no statistical significance in planning of femoral head prosthesis size(P>0.05).The actual combined eccentricity difference and combined eccentricity difference(practical-planning)in Al-HIP group were 1.0(0.2,2.4)mm and 1.1(-2.1,3.2)mm,respectively;which were better than 3.0(1.4,4.9)mm and 3.5(-1.6,6.5)mm in control group(P<0.05).There was no significant difference between two groups in actual osteotomy height of the upper margin of the lesser trochanter(P>0.05).In AI-HIP group,the actual difference of lower extremity length after surgery,the difference of lower extremity length(practical-planning),osteotomy height from the upper margin of lesser trochanter(practical-planning),actual topshoulder distance after surgery,and topshoulder distance(practical-planning)were 1.5(0.2,2.8),1.1(-0.3,2.2),2.1(-2.3,4.1),(15.3±4.1),2.2(-4.8,0.3)mm,respectively;which were better than control group of 2.6(1.3,4.1),2.5(0.3,3.8),5.8(-2.4,7.7),(13.0±4.3),-5.7(-9.4,-2.2)mm(P<0.05).At final follow-up,there were no significant differences in Harris scores of pain,function,deformity,total scores and VAS between two groups(P>0.05).The range of motion score was 4.8±0.6 in AI-HIP group,which was higher than that in control group(4.4±0.8)(P<0.05).Conclusion Compared with traditional template planning,AI-HIP assisted surgical planning system has good accuracy in predicting the prosthetic size of the acetabular cup and femoral stalk,restor-ing joint eccentricity,planning lower limb length,osteotomy height and top shoulder distance on the first unilateral THA,and the clinical follow-up effect is satisfactory.
8.High tibial osteotomy on varus knee osteoarthritis with medial meniscus posterior root injury
Chun-Jiu WANG ; Xiang-Dong TIAN ; Ye-Tong TAN ; Zhi-Peng XUE ; Wei ZHANG ; Xiao-Min LI ; Ang LIU
China Journal of Orthopaedics and Traumatology 2024;37(9):886-892
Objective To explore clinical effect of distal tibial tubercle-high tibial osteotomy(DTT-HTO)in treating knee osteoarthritis(KO A)with medial meniscus posterior root tear(MMPRT).Methods A retrospective analysis was performed on 21 patients with varus KOA with MMPRT from May 2020 to December 2021,including 3 males and 18 females,aged from 49 to 75 years old with an average of(63.81±6.56)years old,the courses of disease ranged from 0.5 to 18.0 years with an average of(5.9±4.2)years,and 4 patients with grade Ⅱ,14 patients with grade Ⅲ,and 3 patients with grade Ⅳ according to Kellgren-Lawrence;14 patients with type 1 and 7 patients with type 2 according to MMPRT damage classification.The distance of medi-al meniscusextrusion(MME)and weight-bearing line ratio(WBLR)of lower extremity were compared before and 12 months after operation.Visual analogue scale(V AS),Western Ontarioand and McMaster Universities(WOMAC)osteoarthritis index,and Lysholm knee score were used to evaluate knee pain and functional improvement before operation,1,6 and 12 months after operation,respectively.Results Twenty-one patients were followed up for 12 to 18 months with an average of(13.52±1.72)months.MME distance was improved from(4.99±1.05)mm before operation to(1.87±0.76)mm at 12 months after operation(P<0.05).WBLR was increased from(15.49±7.04)%before operation to(62.71±2.27)%at 12 months after operation(P<0.05).VAS was decreased from(7.00±1.14)before operation to(2.04±0.80),(0.90±0.62)and(0.61±0.50)at 1,6 and 12 months after operation.WOMAC were decreased from preoperative(147.90±9.88)to postoperative(103.43±8.52),(74.00±9.54)and(47.62±9.53)at 1,6 and 12 months,and the difference were statistically significant(P<0.05).Lysholm scores were increased from(46.04±7.34)before oepration to(63.19±8.93),(81.10±6.41)and(89.29±3.04)at 1,6 and 12 months after operation(P<0.05).Conclusion For the treatment of varus KOA with MMPRT,DTT-HTO could reduce medial meniscus pro-trusion distance,improve the ratio of lower limb force line,and effectively reduce knee pain and improve knee joint function.
9.Impact of cecal ligation and puncture-induced sepsis on the proliferation and differentiation of intestinal stem cells
Xuepeng ZHANG ; Jianlei FU ; Maoxia LIU ; Geng ZHANG ; Tong QIU ; Jiangyuan ZHOU ; Zixin ZHANG ; Xue GONG ; Qinyi FU ; Yi JI ; Siyuan CHEN
Chinese Critical Care Medicine 2024;36(5):496-502
Objective:To analyze the impact of cecal ligation and puncture (CLP)-induced sepsis on the proliferation and differentiation of intestinal epithelial cells.Methods:① Animal experiment: sixteen male C57BL/6 mice were divided into sham operation group (Sham group) and CLP-induced sepsis model group (CLP group) by random number table method, with 8 mice in each group. After 5 days of operation, the jejunal tissues were taken for determination of leucine-rich-repeat-containing G-protein-coupled receptor 5 (LGR5) and intestinal alkaline phosphatase (IAP) by polymerase chain reaction (PCR). The translation of LGR5 was detected by Western blotting. The expression of proliferating cell nuclear antigen (Ki67) was analyzed by immunohistochemistry. IAP level was detected by modified calcium cobalt staining and colorimetry. Immunofluorescence staining was used to detect the expression of Paneth cell marker molecule lysozyme 1 (LYZ1) and goblet cell marker molecule mucin 2 (MUC2). ② Cell experiment: IEC6 cells in logarithmic growth stage were divided into blank control group and lipopolysaccharide (LPS) group (LPS 5 μg/mL). Twenty-four hours after treatment, PCR and Western blotting were used to analyze the transcription and translation of LGR5. The proliferation of IEC6 cells were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining. The transcription and translation of IAP were detected by PCR and colorimetric method respectively.Results:① Animal experiment: the immunohistochemical results showed that the positive rate of Ki67 staining in the jejunal tissue of CLP group was lower than that of Sham group [(41.7±2.5)% vs. (48.7±1.4)%, P = 0.01]. PCR and Western blotting results showed that there were no statistical differences in the mRNA and protein expressions of LGR5 in the jejunal tissue between the CLP group and Sham group (Lgr5 mRNA: 0.7±0.1 vs. 1.0±0.2, P = 0.11; LGR5/β-actin: 0.83±0.17 vs. 0.68±0.19, P = 0.24). The mRNA (0.4±0.1 vs. 1.0±0.1, P < 0.01) and protein (U/g: 47.3±6.0 vs. 73.1±15.3, P < 0.01) levels of IAP in the jejunal tissue were lower in CLP group. Immunofluorescence saining analysis showed that the expressions of LYZ1 and MUC2 in the CLP group were lower than those in the Sham group. ②Cell experiment: PCR and Western blotting results showed that there was no significant difference in the expression of LGR5 between the LPS group and the blank control group (Lgr5 mRNA: 0.9±0.1 vs. 1.0±0.2, P = 0.33; LGR5/β-actin: 0.71±0.18 vs. 0.69±0.04, P = 0.81). The proliferation rate of IEC6 cells in the LPS group was lower than that in the blank control group, but there was no significant difference [positivity rate of EdU: (40.5±3.8)% vs. (46.5±3.6)%, P = 0.11]. The mRNA (0.5±0.1 vs. 1.0±0.2, P < 0.01) and protein (U/g: 15.0±4.0 vs. 41.2±10.4, P < 0.01) of IAP in the LPS group were lower than those in the blank control group. Conclusion:CLP-induced sepsis inhibits the proliferation and differentiation of intestinal epithelial cells, impairing the self-renewal ability of intestinal epithelium.
10.Development and validation of an Assessment Scale of Proactive Health Behavior Ability for the Disabled Elderly in Nursing Homes
Yangli OU ; Xiaoyan LIAO ; Ying PENG ; Hong ZHANG ; Shaohua YIN ; Liyu CHEN ; Xue XIONG ; Xiuli YU ; Lifang TONG ; Yan XIE ; Dan HUO ; Jun SHEN
Chinese Journal of Nursing 2024;59(21):2579-2586
Objective To develop the assessment scale of proactive health behavior ability for the disabled elderly in nursing homes and to test its reliability and validity.Methods The first draft of the scale was formed by literature review,qualitative interviews and Delphi method.From December 2023 to March 2024,525 disabled elderly people from 9 nursing homes in Sichuan Province and Chongqing City were selected as the survey subjects,and item analysis and reliability and validity test were carried out on the scale.30 disabled elderly people were re-investigated after 2 weeks to calculate the retest reliability of the scale.Results The scale consisted of 4 dimensions and 27 items.Exploratory factor analysis extracted 4 common factors,with the cumulative vanance contribution rate of 65.992%,and confirmatory factor analysis showed that the modified model fitting index was within acceptable range.The content validity index at item level was 0.917-1.000,and that at scale level was 0.997.The Cronbach's α coefficient,test-retest reliability and split-half reliability of the total scale were 0.944,0.997 and 0.882,respectively.Conclusion The scale has good reliability and validity,and it can be used to evaluate the proactive health behavior ability of the disabled elderly in nursing homes.

Result Analysis
Print
Save
E-mail