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.

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR. RESULTS: The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01). CONCLUSIONS EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Electroacupuncture ; Phosphatidylinositol 3-Kinase/metabolism* ; Facial Nerve Injuries/therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Beclin-1 ; Glial Cell Line-Derived Neurotrophic Factor ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism* ; Autophagy ; Mammals/metabolism*

Aim To express and purify recombinant hCGH-CTP fusion protein in high-density suspension culture of Chinese hamster ovary cells (CHO-S), and to verify the lipid accumulation effect of rhCGH-CTP on 3T3-L1 mature adipocytes. Methods The recombinant protein expression vector (pcDNA3. 1-rhCGH-CTP) was constructed, achieved by fusing the human glycoprotein hormone beta 5/alpha 2 cDNA with CTP Linker. The expression plasmid was transiently transfected into the suspended CHO-S to express rhCGH-CTP protein and then purified, and the protein biological activity was verified. Intervention with 3T3-L1 mature adipocyte cells for 24 h was performed to detect the changes of intracellular triglyceride (TG) level. Results Western blot results showed that rhCGH-CTP protein was successfully expressed in CHO-S cells, and the yield was up to 715. 4 mg • L~ . The secreted protein was purified by AKTA pure system with higher purity that was up to 90% as identified by SDS-PAGE. In addition, the intracellular cAMP content of mature adipocytes with high expression of TSHR gene significantly increased after intervention with different concentrations of rhCGH-CTP protein by ELISA kit, indicating that rhCGH-CTP protein had biological activity. Oil red 0 staining showed that compared with the control group, the lipid content of mature adipocytes in the intervention groups with different concentrations of rhCGH-CTP protein significantly decreased (P < 0. 05) . Conclusions The rhCGH-CTP protein has been successfully expressed and purified with biological activity, and effectively reduce TG. This research provides an important theoretical basis for further revealing the physiological role of CGH protein and its potential application in clinical practice.

Aim To explore the effects of Lycium berry seed oil on Nrf2/ARE pathway and oxidative damage in testis of subacute aging rats. Methods Fifty out of 60 male SD rats, aged 8 weeks, were subcutaneously injected with 125 mg • kg"D-galactosidase in the neck for 8 weeks to establish a subacute senescent rat model. The presence of senescent cells was observed using P-galactosidase ((3-gal), while testicular morphology was examined using HE staining. Serum levels of testosterone (testosterone, T), follicle-stimulating hormone ( follicle stimulating hormone, FSH ) , luteinizing hormone ( luteinizing hormone, LH ) , superoxide dis-mutase ( superoxide dismutase, SOD ) , glutathione ( glutathione, GSH) and malondialdehyde ( malondial-dehyde, MDA) were measured through ELISA, and the expressions of factors related to aging, oxidative damage, and the Nrf2/ARE pathway were assessed via immunohistochemical analysis and Western blotting. Results After successfully identifying the model, the morphology of the testis was improved and the intervention of Lycium seed oil led to a down-regulation in the expression of [3-gal and -yH2AX. The serum levels of SOD, GSH, T, and FSH increased while MDA and LH decreased (P 0. 05) . Additionally, there was an up-regulated expression of Nrf2, GCLC, NQOl, and SOD2 proteins in testicular tissue ( P 0. 05 ) and nuclear expression of Nrf2 in sertoli cells. Conclusion Lycium barbarum seed oil may reduce oxidative damage in testes of subacute senescent rats by activating the Nrf2/ARE signaling pathway.

Superior vena cava syndrome(SVCS)is a group of clinical syndromes caused by obstruction of the superior vena cava and its major branches from various causes.Pulmonary artery stenosis(PS)is a complication of lung cancer or mediastinal tumours.SVCS combined with PS due to pulmonary metastases from bladder cancer is extremely rare and has not been reported in the literature.Here we reported an old male patient with pulmonary metastases from bladder cancer presenting with swelling of the head,neck and both upper limbs.SVCS combined with PS was clarified by pulmonary artery computed tomography angiography(CTA)and digital subtraction angiography(DSA).Endovascular stenting was used to treat SVCS.Angiography also showed that PS had not caused pulmonary hypertension and did not need to be treated.The swelling of the patient's head,neck and upper limbs was gradually reduced after the procedure.

ObjectiveThe purpose of this study was to investigate the effects of transcutaneous electrical acupoint stimulation (TEAS) on cognitive function of vascular dementia (VD) rats and its mechanism. MethodsVD rat model was established by modified two-vessel occlusion (2-VO). After modeling, TEAS and electroacupuncture (EA) were used to stimulate Baihui and Zusanli points of rats respectively for 14 d. After treatment, novel object recognition test, Morris water maze test, and Y maze test were used to evaluate the spatial memory and learning ability of rats. Hematoxylin and eosin staining was used to observe the morphology of hippocampal neurons. Transmission electron microscopy was used to observe the ultrastructure of hippocampal mitochondria. Enzyme-linked immunosorbent assay kits were used to detected the levels of SOD, CAT, GSH-Px, MDA and ROS in serum of rats. Western blot was used to detect the expression of PGC-1α, TFAM, HO-1, NQO1 proteins in the hippocampus, Keap1 protein in the cytoplasm and Nrf2, NRF1 proteins in the nucleus. ResultsAfter treatment for 14 d, compared to the model group, the escape latency of VD rats decreased, while the discrimination index, the times of rats crossing the original platform area, the residence time in the original platform quadrant, and the percentage of alternation increased. TEAS can improve the structure of hippocampal neurons and mitochondria of VD rats, showing that neurons were arranged more regularly and distributed more evenly, nuclear membrane and nucleoli were clearer, and mitochondrial swelling were reduced, mitochondrial matrix density were increased, and mitochondrial cristae were more obvious. The levels of SOD, GSH-Px and CAT in serum increased significantly, while the concentration of MDA and ROS decreased. TEAS also up-regulated the expression levels of PGC-1α TFAM, NQO1 and HO-1 proteins in the hippocampus and Nrf2, NRF1 proteins in the nucleus, but down-regulated the Keap1 protein in the cytoplasm. ConclusionTEAS can improve cognition, hippocampal neurons and mitochondrial structure of VD rats, and the effect is better than EA. The mechanism may be the activation of PGC-1α mediated mitochondrial biogenesis and antioxidant stress, which also provides a potential therapeutic technology and experimental basis for the treatment of VD.

Objective To compare the effects of 20 mg qd and 10 mg bidadministration of iprrazole enteric-coated tablets on the control of gastric acid in healthy subjects.Methods A randomized,single-center,parallel controlled trial was designed to include 8 healthy subjects.Randomly divided into 2 groups,20 mg qd administration group:20 mg enteric-coated tablets of iprrazole in the morning;10 mg bid administration group:10 mg enteric-coated tablets of iprrazole in the morning and 10 mg in the evening.The pH values in the stomach of the subjects before and 24 h after administration were monitored by pH meter.The plasma concentration of iprazole after administration was determined by HPLC-MS/MS.The main pharmacokinetic parameters were calculated by Phoenix WinNonlin(V8.0)software.Results The PK parameters of iprrazole enteric-coated tablets and reference preparations in fasting group were as follows:The Cmax of 20 mg qd group and 10 mg bid group were(595.75±131.15)and(283.50±96.98)ng·mL-1;AUC0-t were(5 531.94±784.35)and(4 686.67±898.23)h·ng·mL-1;AUC0-∞ were(6 003.19±538.59)and(7 361.48±1 816.77)h·ng·mL-1,respectively.The mean time percentage of gastric pH＞3 after 20 mg qd and 10 mg bid were 82.64％and 61.92％,and the median gastric pH within 24 h were 6.25±1.49 and 3.53±2.05,respectively.The mean gastric pH values within 24 h were 5.71±1.36 and 4.23±1.45,respectively.The correlation analysis of pharmacokinetic/pharmacodynamics showed that there was no significant correlation between the peak concentration of drug in plasma and the inhibitory effect of acid.Conclusion Compared with the 20 mg qd group and the 10 mg bid group,the acid inhibition effect is better,the administration times are less,and the safety of the two administration regimes is good.

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.

Objective To compare the efficacy and safety of empagliflozin and linagliptin in the treatment of patients with type 2 diabetes mellitus(T2DM)with heart failure(HF).Methods Patients with T2DM and HF were randomly into control group and treatment group.Both groups were treated with individualized anti-HF and metformin-based hypoglycemic therapy.On this basis,the control group was given linagliptin orally(5 mg each time,once a day),while the treatment group was given oral administration of empagliflozin 10 mg every day.Patients in both groups were treated continuously for 6 months.The clinical efficacy and blood glucose indicators[fasting blood glucose(FBG),2 h postprandial blood glucose(2 h PBG),hemoglobin A1c(HbA1c)],cardiac molecular markers[N-terminal pro-brain natriuretic peptide(NT-proBNP),fibroblast growth factor 23(FGF23),copeptin(CPP)]and caridac function indicators[left ventricular end-diastolic diameter(LVEDD),left ventricular ejection fraction(LVEF),left ventricular remodeling index(LVRI)]before and after treatment were compared,and the adverse drug reactions were recorded.Results There were 40 cases in treatment group and 40 cases in control group.After treatment,the total effective rates in treatment group and control group were 97.50％(39 cases/40 cases)and 80.00％(32 cases/40 cases),with no significant difference(P＜0.05).The FBG levels in treatment group and control group were(7.64±1.18)and(7.83±1.24)mmol·L-1;2 h PBG levels were(8.97±1.46)and(9.04±1.35)mmol·L-1;HbA1c levels were(7.58±1.27)％and(7.65±1.42)％,all with no significant difference(all P＞0.05).The NT-proBNP levels in treatment group and control group were(612.53±204.62)and(1 045.24±316.75)pg·mL-1;FGF23 levels were(362.74±62.61)and(493.27±74.64)μg·L-1;CPP levels were(12.58±3.43)and(16.87±4.36)pmol·L-1;LVEDD values were(51.19±2.36)and(53.35±2.24)mm;LVEF values were(52.69±3.38)％and(50.28±3.75)％;LVRI values were(2.62±0.29)and(2.96±0.33)kg·L-1,all with significant difference(all P＜0.05).The incidence rates of adverse reactions in treatment group and control group were 5.00％(2 cases/40 cases)and 10.00％(4 cases/40 cases),with no significant difference(P＞0.05).Conclusion Both empagliflozin and linagliptin can effectively reduce the blood glucose in patients with T2DM complicated with HF.Empagliflozin can better promote the improvement of cardiac function in patients without significantly increase the incidence of adverse drug reactions.

Objective To explore whether the cognitive function of central obese mice is decreased by affecting the expression of brain-derived neurotrophic factor(BDNF)in hippocampus.Methods Healthy mice at the neonatal stage were divided into normal group and model group at random.To obtain the obese models,model group mice were injected at cervical subcutaneous with 10％L-monosodium glutamate(MSG;3 mg·g-1·d-1)for 5 days.The normal group was injected with the same dose of 0.9％NaCl.In addition,mice were removed according to the requirements.Finally,we got 8 mice in each group.The following parameters were compared:body weight,Lee's index and levels of the serum lipid.The BDNF expression levels in hippocampal tissue were measured using western blotting.Results At the 8th weekend,the body weight of the model and normal groups was(49.01±2.47)and(41.27±3.28)g;the Lee's indexes were(357.14±9.24)and(330.15±7.37)g1/3·cm-1;triglyceride levels were(1.37±0.52)and(0.73±0.31)mmol·L-1;total cholesterol levels were(2.98±0.18)and(1.98±0.30)mmol·L-1;low-density lipoprotein levels were(0.31±0.03)and(0.24±0.02)mmol·L-1;high-density lipoprotein levels were(2.70±0.15)and(1.98±0.40)mmol·L-1;the differences were statistically significant(P＜0.05,P＜0.01),which were consistent with the characteristics of the central obesity model.The BDNF protein expression levels in the hippocampus of the model and normal groups were 6.02 x 104±626.53 and 7.04 x 104±1 440.81,which has statistically significant(P＜0.01).Conclusion The cognitive function of central obese mice may be decreased by down-regulating the expression of BDNF in hippocampus.