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.

The analysis presented here is based on the blood components of Guanxin Qiwei tablets, the key anti-atherosclerosis pathway of Guanxin Qiwei tablets was screened by network pharmacology, and the anti-atherosclerosis mechanism of Guanxin Qiwei tablets was clarified and verified by cell experiments. HPLC-Q-Exactive-MS/MS technique was used to analyze the components of Guanxin Qiwei tablets into blood, to determine the precise mass charge ratio of the compounds, and to conduct a comprehensive analysis of the components by using secondary mass spectrometry fragments and literature comparison. Finally, a total of 42 components of Guanxin Qiwei tablets into blood were identified. To better understand the interactions, we employed the Swiss Target Prediction database to predict the associated targets. Atherosclerosis (AS) disease targets were searched in disease databases Genecard, OMIM and Disgent, and 181 intersection targets of disease targets and component targets were obtained by Venny 2.1.0 software. Protein interactions were analyzed by String database. The 32 core targets were selected by Cytscape software. Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed in DAVID database. It was found that the anti-atherosclerosis pathways of Guanxin Qiwei tablets mainly include lipid metabolism and atherosclerosis and AGE-RAGE signaling pathway in diabetic complications and other signal pathways. The core targets and the core compounds were interlinked, and it was found that cryptotanshinone and tanshinone ⅡA in Guanxin Qiwei tablets were well bound to TNF, PPARγ, AKT1, PTG2 and other targets. The lipid metabolism and atherosclerotic pathway was verified using human hl-7702 hepatocytes. This study preliminarily identified the potential pharmacodynamic components of Guanxin Qiwei tablets in the treatment of AS diseases and predicted their pathways of action, and verified the relationship between regulating lipid metabolism and atherosclerosis of Guanxin Qiwei tablets in vitro, providing a reference for the further study of the pharmacodynamic material basis and mechanism of action of this prescription. This experiment was approved by the Medical Ethics Committee of Inner Mongolia Medical University (No. YKD202401262).

OBJECTIVE To investigate the potential mechanism of berberine improving diabetes mellitus type 2 （T2DM） combined with metabolic-associated fatty liver disease （MAFLD） by regulating ceramide. METHODS Thirty-two db/db mice with blood glucose levels＞11.1 mmol/L （T2DM model） were divided into four groups： model group， berberine low- and high-dose groups [100， 200 mg/（kg·d）] and metformin group [300 mg/（kg·d）]， with 8 mice in each group. Additionally， 8 wt/wt mice were selected as the normal control group. Mice in each group were administered the corresponding drug solution or water by gavage once daily for a continuous period of 6 weeks. During the experiment， the body weight of the mice was monitored， and the differences in final body weight were analyzed. After the last administration， the body shape of the mice in each group was observed， and their fasting blood glucose （FBG） and the lipid indicators [total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）] were measured. Fasting serum insulin （FINS） levels were also measured， and the insulin resistance index HOMA-IR） and insulin sensitivity index （ISI） were calculated. Liver weight， liver index and serum liver function indicators [alanine transaminase （ALT）， aspartate transaminase（AST）] were assessed， and hepatic histopathological changes were observed. Additionally， the expression of fatty acid synthesis-related proteins [sterol regulatory element-binding protein 1 （SREBP1）， fatty acid synthase （FASN）， acetyl-CoA carboxylase 1 （ACC1）] in liver tissue was examined. Serum samples from the normal control group， model group， and berberine high-dose group were collected for non-targeted lipidomics analysis and validation. RESULTS Compared with the model group， the pathological changes， including disordered liver tissue cell arrangement and lipid vacuoles， were significantly improved in the berberine low- and high-dose groups. The significant decreases or down-regulations were observed in body weight in the last week， as well as FBG， TC， TG， and LDL-C levels， HOMA-IR （except for the berberine low-dose group）， liver weight， liver index， AST and ALT levels， and protein expressions of SREBP1， FASN and ACC1. Additionally， HDL-C levels， FINS （except for the berberine high-dose group）， and ISI （except for the berberine low-dose group） were significantly increased （P＜0.05）. A total of 21 potential differential metabolites， including multiple types of ceramides， were identified； these metabolites were primarily enriched in sphingolipid metabolism and glycerophospholipid metabolism pathways. Verification experiments confirmed that high-dose berberine significantly reduced the serum content of ceramide in model mice （P＜0.05）. CONCLUSIONS Berberine reduces insulin resistance， improves liver damage and lipid accumulation in the T2DM combined with MAFLD mice， and these effects may be related to the reduction of ceramide content.

This work was aimed at predicting and verifying B-cell epitopes of SARS-CoV-2 E protein through bioinformatics methods,and clarifying the dominant B cell epitopes with mouse polyclonal antibody serum prepared through SARS-CoV-2 re-combinant E protein immunization and human positive serum vaccinated with inactivated SARS-CoV-2 vaccine.The structural and B-cell linear epitopes of SARS-CoV-2 E protein were predicted with SOPMA,Expasy,SWISS-MODEL,IEDB database,and Bepid-2.0 software.Candidate epitopes were expressed as GST-tagged recombinant protein fragments in an E.coli sys-tem,and their immunoreactivity with mouse and human poly-clonal positive serum against SARS-CoV-2 E protein was de-tected by western blotting and indirect ELISA,respectively.The epitope prediction results showed that E protein contained linear B cell epitopes Ser6-Val14 and Tyr57-Pro71,and the conformational epitopes of Glu8-Val12,Leu39-Tyr59,and Ser60-Leu65.The GST tagged recombinant E protein fragments of E1 and E3,containing Ser6-Val14 and Tyr57-Pro71 epitopes,respectively,as well as E2 without an epitope sequence as a control,were expressed in an E.coli expression system and successfully purified with an Ni-NTA column.Western blotting and indirect ELISA analysis indicated that all mouse and human SARS-CoV-2 positive sera positively reacted with only E1 and E3 proteins,but negatively reacted with E2 protein,thus indicating that the corresponding epitope prediction with Ser6-Val14 and Tyr57-Pro71 was correct.This study successfully predicted and preliminarily identified two linear B cell epitopes of SARS-CoV-2 E protein,thus providing a reference for the preparation of new coronavirus vaccines and the analysis of immune response characteristics.

Objective:To investigate the effect of anthoxanthin on the proliferation and apopto-sis of human gastric cancer cell line SGC7901 and its possible mechanism.Methods:SGC7901 was cultured in the medium containing different concentrations(0,20,40,80 μ mol/L)of antho-cyanin.Hoechst staining,MTT colorimetry and flow cytometry were used to verify the effect of Form on the inhibition rate,cell cycle,nuclear morphology and apoptosis.Western Blotting was used to test the level of β-Catenin、p-β-Catenin,CyclinD1,CDK4,p-AKT,AKT,BCL-2,BAX,caspase3 and other proteins.The mRNA expression of BCL-2,CDK4,CDK6,AKT,CyclinD1,BAX,Caspase3 was detected by RT-PCR.Results:MTT results showed that the inhibitory effect of Form on SGC7901 was concentration dependent and time dependent.Hoechst staining showed that the cells in the experimental group(20,40,80 μ mol/L),the phenomenon of pyknosis and dissolution of the nucleus,even granular aggregation after rupture.Flow cytometry showed that the apoptosis rate of the experimental group(20 μ mol/L,40 μ mol/L,80 μ mol/L)was 17.0％,21.5％,32.5％respectively after treated with different concentrations of Form for 48 hours,which was positively correlated with the drug concentration.RT-PCR showed that caspase3 and BAX mRNA expression increased with the increase of Form intervention concentration(P＜0.01);the mRNA expression of BCL-2,CDK4,CDK6,AKT,CyclinD1 decreased(P＜0.01).WB results showed that β-Catenin、p-β-Catenin,Cy-clinD1,CDK4 and p-AKT,AKT,BCL-2 decreased with the increase of Form intervention concentra-tion(P＜0.01);The relative expression of caspase3,BAX and other proteins increased(P＜0.01).Con-clusion:Form can promote apoptosis of SGC7901,and the possible mechanism is to inhibit Wnt/β-Catenin signal;it also mediates the activation of Caspase family.

Objective:To investigate the clinical effect of pulsed thulium laser(PTL)combined with triamcinolone acetonide injection in the treatment of failed posterior urethral anastomosis(FPUA).Methods:This retrospective study included 35 male pa-tients treated in Gongli Hospital for failed posterior urethral anastomosis from January 2018 to December 2023.All the patients under-went direct-vision internal urethrotomy(DVIU)with transurethral PTL(the PTL group,n=15)or transurethral plasma(the TUP group,n=20),and all received intralesional injection of triamcinolone acetonide.We followed up the patients for a median of 21 months,recorded the age,length of urethral stricture,operation time,pre-and post-operative maximum urinary flow rate(Qmax),postoperative complications and recurrence of urethral stricture,and compared the data obtained between the two groups.Results:All the patients smoothly completed the treatment procedures.No statistically significant differences were observed in the age,length of urethral stricture,operation time and postoperative complications between the two groups(P>0.05).The median follow-up time for the thulium laser group and plasma group was 21.0 months(IQR 16.0-24.0)and 21.0 months(IQR 17.0-25.0),respectively,with a statistically significant difference observed in the maximum urine flow rate before and after surgery at the 12-month mark(P<0.01).No significant disparity was found in terms of relapse-free survival between the two groups(P=0.398)Conclusion:Pulsed thulium laser combined with triamcinolone acetonide injection can effectively maintain a short-term cicatricial stability of the ure-thral stricture and satisfactory urethral patency,obviously superior to plasmotomy as a remedial treatment of urethral stricture after failed posterior urethral anastomosis.

AIM To establish a UPLC-MS/MS method for the simultaneous content determination of gallic acid,protocatechuic acid,neomangiferin,catechin,caffeic acid,mangiferin,isomangiferin,albiflorin,paeoniflorin,vitexin,liquiritin,scutellarin,baicalin,liquiritigenin,timosaponin BⅡ,quercetin,wogonoside,benzoylpaeoniflorin,isoliquiritigenin,honokiol,magnolol,norarecaidine,arecaidine,arecoline,epicatechin,baicalein,glycyrrhizinate and wogonin in Dayuan Drink.METHODS The analysis was performed on a 35℃thermostatic Syncronis C18 column(100 mm×2.1 mm,1.7 μm),with the mobile phase comprising of 0.1%formic acid-acetonitrile flowing at 0.3 mL/min in a gradient elution manner,and electron spray inoization source was adopted in positive and negative ion scanning with select reaction monitoring mode.RESULTS Twenty-eight constituents showed good linear relationships within their own ranges(R2≥0.991 0),whose average recoveries were 95.60%-103.53%with the RSDs of 0.60%-5.45%.CONCLUSION This rapid,simple,selective,accurate and reliable method can be used for the quality control of Dayuan Drink.

Objective To develop a biological safety protection third-level(BSL-3)laboratory based on folding-modular shelters to solve the problems of the existing laboratories in space and function expansion,large-scale deployment and low-cost transportation.Methods The BSL-3 laboratory was composed of a folding combined shelter module,a ventilation and purification module,a power supply and distribution module,a monitoring and communication module,a control system module and an equipment module.The folding combined shelter module used a leveling base frame as the foundation and a lightweight panel as the enclosure mechanism,and was divided into an auxiliary area and a protection protected area;the ventilation and purification module was made up of an air supply unit and an air exhaust unit,the air supply unit was integrated with a fresh-air air conditioner and the exhaust unit was equipped with a main fan,a standby fan and a bag in/bag out filter;the control system module adopted a supervision mode of decentralized control and centralized management,which executed communication with the data server as the center and Profinet protocol and MODBUS-TCP.Results The BSL-3 laboratory proved to meet the requirements of relevant standards in internal microenvironment,airflow direction,airtightness,working condition and disinfection effect.Conclusion The BSL-3 laboratory is compatible with large-scale transport and deployment and facilitates reliable and safe experiments for epidemic prevention and control and cross-regional support.[Chinese Medical Equipment Journal,2024,45(3):41-46]

Objective:The transjugular or transfemoral approach is used as a common method for hepatic venous pressure gradient (HVPG) measurement in current practice. This study aims to confirm the safety and effectiveness of measuring HVPG via the forearm venous approach.Methods:Prospective recruitment was conducted for patients with cirrhosis who underwent HVPG measurement via the forearm venous approach at six hospitals in China and Japan from September 2020 to December 2020. Patients' clinical baseline information and HVPG measurement data were collected. The right median cubital vein or basilic vein approach for all enrolled patients was selected. The HVPG standard process was used to measure pressure. Research data were analyzed using SPSS 22.0 statistical software. Quantitative data were used to represent medians (interquartile ranges), while qualitative data were used to represent frequency and rates. The correlation between two sets of data was analyzed using Pearson correlation analysis.Results:A total of 43 cases were enrolled in this study. Of these, 41 (95.3%) successfully underwent HVPG measurement via the forearm venous approach. None of the patients had any serious complications. The median operation time for HVPG detection via forearm vein was 18.0 minutes (12.3~38.8 minutes). This study confirmed that HVPG was positively closely related to Child-Pugh score ( r = 0.47, P = 0.002), albumin-bilirubin score ( r = 0.37, P = 0.001), Lok index ( r = 0.36, P = 0.02), liver stiffness ( r = 0.58, P = 0.01), and spleen stiffness ( r = 0.77, P = 0.01), while negatively correlated with albumin ( r = -0.42, P = 0.006). Conclusion:The results of this multi-centre retrospective study suggest that HVPG measurement via the forearm venous approach is safe and feasible.

Purpose To explore the application value of clinical-ultrasound parameter model in secondary hyperparathyroidism(SHPT).Materials and Methods A total of 86 patients(134 lesions)with renal insufficiency who underwent maintenance hemodialysis in the First Affiliated Hospital of Shihezi University from October 2020 to August 2022 were included and divided into group 1 according to the level of parathyroid hormone(iPTH)(iPTH＜300 pg/ml),group 2(iPTH 300-800 pg/ml)and group 3(iPTH≥800 pg/ml),all patients underwent gray-scale parathyroid ultrasound and acoustic palpation tissue quantitative imaging examinations.The characteristics of glandular gray-scale ultrasound and virtual touch tissue imaging quantification parameters between different groups,combined with relevant clinical indicators,established a clinical-ultrasound parameter model,used multiple linear regression to analyze the correlation between the model and iPTH,explored the independent risk factors of iPTH,and evaluated this model to evaluate SHPT the value of.Results There were significant differences in dialysis age,phosphorus,alkaline phosphatase,serum creatinine,corrected calcium and phosphorus product,lesion size,number,echo,shear wave velocity(SWV)max,SWVcen,and SWVmean among the three groups(F/x2/H=6.396-53.524,all P＜0.05).Dialysis age,phosphorus,alkaline phosphatase,and SWVratio were independent influencing factors of iPTH level(β=0.514,0.422,0.226,-0.368,all P＜0.005).The area under the curve,sensitivity,specificity and accuracy of the model for diagnosing SHPT and predicting surgical treatment with iPTH levels of 300 pg/ml and 800 pg/ml were 0.967,95.00％,100.00％,97.73％and 0.824,77.42％,71.43％and 90.00％,respectively.Conclusion Dialysis age,phosphorus,alkaline phosphatase and SWVratio are independent influencing factors of iPTH level,and the clinical-ultrasound parameter model is of great value in accurately assessing the severity of SHPT.