Glucose transporters (GLUTs) are pivotal membrane proteins that facilitate the passive transport of glucose into cells. However, their aberrant overexpression is closely linked to the Warburg effect and chemotherapy resistance of tumors. GLUTs are complex multi-pass transmembrane proteins that require detergents for extraction from the cell membrane during preparation. The persistent presence of detergents in the sample can disrupt lipid-protein interactions, potentially leading to conformational distortion and functional losses of GLUTs, severely hindering the research into their structures and transport mechanisms. To eliminate detergent interference and preserve its authentic conformation, this study employs nanodisc technology and utilizes the self-assembly of the membrane scaffold protein MSP1E3D1 and phospholipids to produce a biomimetic membrane environment, thereby overcoming the limitations of conventional methods. The C-terminal His10-tagged GLUT1 was heterologously expressed in the insect cell Sf9/Bac-to-Bac system, and the GLUT1-nanodisc complex was obtained after detergent solubilization, affinity chromatography purification via anti-His antibody resin, and self-assembly. The successfully reconstituted nanodisc complex was further purified by Ni-NTA affinity chromatography. Nanodisc reconstitution produced monodisperse GLUT1 particles that retained native secondary structure, as confirmed by far-UV circular dichroism (CD) spectroscopy and dynamic light scattering (DLS). Unlike conventional detergent micelles, which lack a true lipid bilayer, distort transmembrane-helix topology, and occlude ligand-binding sites, the nanodisc platform embeds GLUT1 in a phospholipid bilayer that preserves its authentic conformation while eliminating detergent interference. The resulting GLUT1-nanodisc complex is therefore a superior scaffold for high-resolution cryo-EM structural analysis, permitting detailed interrogation of the transporter's conformational cycle, its interactions with partner proteins, and downstream structure-guided, high-throughput drug screening.
Nanostructures/chemistry* ; Glucose Transporter Type 1/biosynthesis* ; Humans ; Animals ; Phospholipids/chemistry* ; Detergents/chemistry*

Objective:To identify the risk factors for postoperative sleep disturbances in elderly patients undergoing thoracic surgery.Methods:A total of 200 elderly patients of both sexes, aged>65 yr, of American Society of Anesthesiology physical status Ⅱ or Ⅲ, scheduled for elective thoracic surgery, were enrolled in the study.Data regarding patient age, gender, body mass index (BMI), American Society of Anesthesiologists physical status, history of hypertension, history of diabetes mellitus, operation method, type of operation, operation time, intraoperative blood loss, use of intraoperative nerve block and use of dexmedetomidine in patient-controlled intravenous analgesia (PCIA) were collected.The patients were followed up after operation, the occurrence of postoperative pain at 48 h after operation was recorded, and patients′ subjective sleep quality at 48 h after operation was assessed using the Pittsburgh Sleep Quality Index Questionnaire (PSQI). Patients were divided into 2 groups according to PSQI score: non-postoperative sleep disturbances group (PSQI score<5) and postoperative sleep disturbances group (PSQI score≥5). A multivariate logistic regression was used to identify the risk factors for postoperative sleep disturbances in elderly patients undergoing thoracic surgery.Results:A total of 169 patients were included in this study, and the incidence of postoperative sleep disturbances was 45%.The results of logistic regression analysis showed that history of preoperative insomnia, BMI≥24 kg/m 2, diabetes mellitus, thoracic surgery, radical resection of lung cancer, radical resection of esophageal cancer, operation time≥120 min and moderate and severe postoperative pain were risk factors for postoperative sleep disturbances in elderly patients undergoing thoracic surgery, and use of intraoperative nerve block and use of dexmedetomidine during PCIA were protective factors for postoperative sleep disturbances in elderly patients ( P<0.05). Conclusion:History of preoperative insomnia, BMI≥24 kg/m 2, diabetes mellitus, thoracic surgery, radical resection of lung cancer, radical resection of esophageal cancer, operation time≥120 min, moderate and severe postoperative pain are risk factors and use of intraoperative nerve block and use of dexmedetomidine during PCIA are protective factors for postoperative sleep disturbances in elderly patients undergoing thoracic surgery.

OBJECTIVE： To investigate the protective effect of total flavonoids from the leaves of Choerospondias axillaris （TFLC） on myocardial ischemia reperfusion injury （MIRI） model rats. METHODS： Male SD rats were randomly divided into sham operation group， model group， positive control group （verapamil， 0.02 g/kg）， TFLC low-dose and high-dose groups （0.1， 0.4 g/kg）， with 10 rats in each group. Administration groups were intragastrically given relevant medicine （2 mL/100 g）； sham operation group and model group were given constant volume of normal saline intragastrically， once a day， for consecutive 7 d. After last medication， MIRI model was induced by modified ligation method. The times and duration of ventricular tachycardia （VT） and ventricular fibrillation （VF） in rats were recorded with biological function experiment system during reperfusion period.The activity of CK and contents of TNF-α， IL-6， NF-κB and NO in serum were determined by ELISA double antibody clip art assay. The morphological characteristics of myocardial tissue was observed by HE staining. The myocardial infarction scope （i.e. the ratio of myocardial tissue mass to ventricular mass） was measured by TTC method. RESULTS： Compared with sham operation group， the times and duration of VT and VF were increased or prolonged significantly in model group； CK activity， serum contents of TNF-α， IL-6 and NF-κB were enhanced or increased significantly， while NO content was decreased significantly （P＜0.05 or P＜0.01）. Obvious myocardial infarction focus， serious cell structure damage， disorderly muscle fibers arrangement， cell nucleus pyknosis and accompanied inflammatory cell infiltration were all observed in cardiac tissue； the mass of infarcted myocardial tissue and ventricular as well as the scope of myocardial infarction increased significantly （P＜0.01）. Compared with model group， the times and duration of VT and VF were decreased or shortened significantly in administration groups； CK activity， serum contents of TNF-α， IL-6， NF-κB were decreased significantly， while NO content was increased significantly （P＜0.05 or P＜0.01）. The above symptoms of myocardial injury were improved；the mass of infarcted myocardial tissue and ventricular as well as the scope of myocardial infarction was significantly reduced （P＜0.05 or P＜0.01）. CONCLUSIONS： TFLC can relieve MIRI-induced ischemic arrhythmia and myocardial damage， reduce the release of inflammatory factors， promote the recovery of myocardial and endothelial cell function， reduce the scope of myocardial infarction and has a certain protective effect.

Objective To evaluate the copy number variation of FCGR3B gene in Henan Han systemic lupus erythematosus (SLE) patients and healthy controls,and explore the association between FCGR3B gene copy number variants (CNVs) and lupus nephritis (LN) susceptibility in Henan Han population.Methods FCGR3B CNVs was investigated in 142 SLE patients with nephritis,187 SLE patients without nephritis and 328 healthy controls.A modified methodology based on competitive PCR named Multiplex AccuCopyTM Kit was used to detect FCGR3B copy number.Clinical and laboratory data were collected retrospectively from the medical record.Logistic regression analysis was used to determine the association of FCGR3B copy number variants with LN susceptibility.Rank correlation was used to determine the correlations between FCGE3B copy number variants and clinical phenotypes of LN.Results No significant difference was detected in the copy number variations of FCGR3B in different groups.Low copy number of FCGR3B was more commonly seen in patients with nephritis (P=0.042),and was a risk factor for LN (OR=2.059; 95％ CI:1.081-3.921; P=0.028).However,high copy number (＞ 2) had no effect on SLE patients without nephritis(OR=1.152; 95％CI:0.711-1.866; P=0.565) and LN patients (OR=0.838; 95％ CI:0.529-1.329; P=0.454).There were no associations between FCGR3B copy number variants and clinical phenotypes and immunologic characteristics of LN.Conclusion The low copy number of FCGR3B is a risk factor for LN in Henan Han population.