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.

ObjectiveTo observe the effect of Yangxin Tongmai Formula （养心通脉方） by midnight-noon ebb-flow administration method for rat models of premature coronary heart disease （PCHD） with blood stasis syndrome， and to explore the possible mechanism of action from the perspective of DNA methylation differential gene expression. MethodsThere were 3 SD rats in each of the blank group， model group and Yangxin Tongmai Formula group， and the rats in the model group and Yangxin Tongmai Formula group were fed with high-fat chow plus vitamin D3 by gavage plus isoproterenol hydrochloride by subcutaneous injection to construct rat models of PCHD with blood stasis syndrome. After successful modelling， rats in Yangxin Tongmai Formula group were gavaged with 18 g/（kg‧d） of Yangxin Tongmai Formula， and rats in blank group and the model group were gavaged with 4 ml/（kg‧d） of 0.9% NaCl solution， and serum samples of rats in each group were collected for DNA methylation sequencing after 3 weeks to screen for the relevant DNA methylation differentiation genes. In addition， rats with successful modelling of PCHD with blood stasis were randomly divided into model group， Yangxin Tongmai Formula with midnight-noon ebb-flow administration method group ［18 g/（kg‧d） of Yangxin Tongmai Formula was gavaged twice in the heart channel period （12：00） and pericardium channel period （20：00）］， the Yangxin Tongmai Formula control group ［18 g/（kg‧d） of Yangxin Tongmai Formula was gavaged twice at 8：00 and 18：00］ and the Atorvastatin Calcium group ［atorvastatin calcium tablets solution 1.8 mg/（kg‧d） at the same intervention time as that in Yangxin Tongmai Formula control group］， and set up a blank group of 8 rats in each group. The model group and blank group were gavaged with 0.9% NaCl solution 4 ml/（kg‧d） for the same time as the Yangxin Tongmai Formula control group. After 3 weeks of gavage， the blood lipids ［including total cholesterol （TC）， low-density lipoprotein （LDL）， high-density lipoprotein （HDL）］ levels of rats in each group were detected； the HE staining of myocardial tissues and thoracic aorta was used to observe the pathomorphological changes； the levels of serum inflammation indexes ［tumour necrosis factor alpha （TNF-alpha）， lipopolysaccharide （LPS）， and interleukin 10 （IL-10）］ were detected； immunoprecipitation-realtime fluorescence quantitative PCR was used to detect the relative expression of cardiac tissue screening differential genes. ResultsThe genes screened for differentially methylated regions were calmodulin 2 （Calm2）， calcium voltage-gated channel subunit α1s （Cacna1s）， and phospholipase Cβ1 （Plcb1）. Compared with the blank group， rats in the model group showed elevated levels of TC， LDL， TNF-α and LPS， and decreased levels of HDL and IL-10 （P＜0.05 or P＜0.01）； HE staining showed obvious swelling of myocardial fibres， accompanied by a large number of inflammatory cell infiltration， and thickening of the inner wall of the aortic vessels with internal wall damage， which was visible as a large number of lipid cholesterol crystals and obvious inflammatory cell infiltration. Compared with the model group， the TC， LDL， TNF-α and LPS contents of rats in the Yangxin Tongmai Formula with midnight-noon ebb-flow administration method group， the Yangxin Tongmai Formula control group， and the atorvastatin calcium group all reduced， and the contents of HDL and IL-10 all elevated （P＜0.05）， with the improvement of myocardial tissue damage and the reduction of inflammatory infiltration， and the improvement of the damage of the inner lining of the thoracic aorta and the reduction of lipid infiltration. Compared with Yangxin Tongmai Formula control group， LDL， TNF-α and LPS contents reduced， and IL-10 contents increased in the midnight-noon ebb-flow administration method group （P＜0.05）. Compared with the model group， the relative expression of Calm2 and Plcb1 genes decreased and the relative expression of Cacna1s gene increased in Yangxin Tongmai Formula control group and the midnight-noon ebb-flow administration method group （P＜0.05）； compared with the Yangxin Tongmai Formula control group， the relative expression of Calm2 gene decreased and the relative expression of Cacna1s gene increased in the midnight-noon ebb-flow administration method group （P＜0.05）. ConclusionThe intervention of Yangxin Tongmai Formula in the heart channel period （12：00） and pericardium channel period （20：00） was more effective in improving the blood lipid level， inhibiting inflammation， and improving myocardial tissue damage in rats of PCHD with blood stasis syndrome， and Calm2 and Cacna1s genes may be the key targets of Yangxin Tongmai Formula in intervening the blood stasis syndrome of PCHD.

BACKGROUND:Intestinal acute graft-versus-host disease is one of the most aggressive complications after allogeneic hematopoietic stem cell transplantation with high lethality.How to improve intestinal inflammation and regulate autophagy by applying traditional Chinese medicine in order to treat intestinal acute graft-versus-host disease is a worthwhile research issue nowadays. OBJECTIVE:To investigate the mechanism of Huangqintang modulating intestinal flora for the treatment of intestinal acute graft-versus-host disease. METHODS:CB6F1 mice were irradiated with 60Co X radiation at a total dose of 8 Gy,and then single nucleated cell suspensions(bone marrow cells+splenocytes)from Balb/c H-2d mice were injected into the tail vein in order to prepare a model of intestinal acute graft-versus-host disease.These samples were randomly divided into the model group and the high-,moderate-,and low-dose Huangqintang groups.After modeling,the model,high-,moderate-,and low-dose groups received different doses of Huangqintang or an equal volume of saline by continuous gavage for 14 days.Clinical acute graft-versus-host disease grading,and survival time was recorded.Small intestinal tissues from each group were stained with hematoxylin and eosin for small intestinal mucosal pathology scoring.The intestinal flora of mice in each group was detected using 16S rDNA sequencing.Autophagy-related markers were detected using immunofluorescence,immunohistochemistry,and PCR. RESULTS AND CONCLUSION:(1)Compared with the model group,the survival time of mice was significantly prolonged(P<0.01);the clinical acute graft-versus-host disease scores were significantly reduced(P<0.01);the pathological grading scores of the small intestinal mucosa were significantly diminished(P<0.01);the levels of the small intestinal tissue inflammatory factors tumor necrosis factor-α,interleukin-1β,and interleukin-6,were significantly decreased(P<0.01);the structural integrity of the small intestinal mucosal epithelium was partially restored in mice after the intervention of moderate and high-dose Huangqintang.(2)The study of intestinal flora found that compared with the model group,the pro-inflammatory strain Enterococcus was significantly reduced(P<0.05),while beneficial bacteria such as Clostridium_innocuum and Rhodococcus,a pro-autophagy bacterium,were significantly elevated(P<0.05)in the moderate-dose Huangqintang group.(3)Compared with the model group,the autophagy markers were significantly elevated in the moderate-dose Huangqintang group(P<0.05);under transmission electron microscopy,the number of autophagic vacuoles of moderate-dose Huangqintang group increased significantly.(4)The results showed that Huangqintang significantly reduced the abundance of conditionally pathogenic bacteria and the level of inflammatory factors in small intestinal tissues,and increased the relative abundance of beneficial bacteria and promoted the expression of autophagy in the small intestinal mucosa,which resulted in a significant improvement of intestinal symptoms in mice with acute graft-versus-host disease.

BACKGROUND:Degenerative scoliosis is defined as a condition that occurs in adulthood with a coronal cobb angle of the spine>10° accompanied by sagittal deformity and rotational subluxation,which often produces symptoms of spinal cord and nerve compression,such as lumbar pain,lower limb pain,numbness,weakness,and neurogenic claudication.The finite element method is a mechanical analysis technique for computer modelling,which can be used for spinal mechanics research by building digital models that can realistically restore the human spine model and design modifications. OBJECTIVE:To review the application of finite element method in the etiology and treatment of degenerative scoliosis. METHODS:The literature databases CNKI,PubMed,and Web of Science were searched for articles on the application of finite element method in degenerative scoliosis published before October 2023.Search terms were"finite element analysis,biomechanics,stress analysis,degenerative scoliosis,adult spinal deformity"in Chinese and English.Fifty-four papers were finally included. RESULTS AND CONCLUSION:(1)The biomechanical findings from the degenerative scoliosis model constructed using the finite element method were identical to those from the in vivo experimental studies,which proves that the finite element method has a high practical value in degenerative scoliosis.(2)The study of the etiology and treatment of degenerative scoliosis by the finite element method is conducive to the prevention of the occurrence of the scoliosis,slowing down the progress of the scoliosis,the development of a more appropriate treatment plan,the reduction of complications,and the promotion of the patients'surgical operation.(3)The finite element method has gradually evolved from a single bony structure to the inclusion of soft tissues such as muscle ligaments,and the small sample content is increasingly unable to meet the research needs.(4)The finite element method has much room for exploration in degenerative scoliosis.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

The alternative pathway (AP) of the complement system is a key contributor to the pathogenesis of several diseases including paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), C3 glomerular disease (C3G) and age-related macular degeneration (AMD). Complement factor B (CFB) is a trypsin-like serine protein that circulates in the human bloodstream in a latent form. As a key node of the alternative pathway, it is an important target for the treatment of diseases mediated by the complement system. With the successful launch of iptacopan, the CFB small molecule inhibitors has become a current research hotspot, a number of domestic and foreign pharmaceutical companies are actively developing CFB small molecule inhibitors. In this paper, the research progress of CFB small molecule inhibitors in recent years is systematically summarized, the representative compounds and their activities are introduced according to structural types and design ideas, so as to provide reference and ideas for the subsequent research on CFB small molecule inhibitors.

Locomotion, a fundamental motor function encompassing various forms such as swimming, walking, running, and flying, is essential for animal survival and adaptation. The mesencephalic locomotor region (MLR), located at the midbrain-hindbrain junction, is a conserved brain area critical for controlling locomotion. This review highlights recent advances in understanding the MLR’s structure and function across species, from lampreys to mammals and birds, with a particular focus on insights gained from optogenetic studies in mammals. The goal is to uncover universal strategies for MLR-mediated locomotor control. Electrical stimulation of the MLR in species such as lampreys, salamanders, cats, and mice initiates locomotion and modulates speed and patterns. For example, in lampreys, MLR stimulation induces swimming, with increased intensity or frequency enhancing propulsive force. Similarly, in salamanders, graded stimulation transitions locomotor outputs from walking to swimming. Histochemical studies reveal that effective MLR stimulation sites colocalize with cholinergic neurons, suggesting a conserved neurochemical basis for locomotion control. In mammals, the MLR comprises two key nuclei: the cuneiform nucleus (CnF) and the pedunculopontine nucleus (PPN). Both nuclei contain glutamatergic and GABAergic neurons, with the PPN additionally housing cholinergic neurons. Optogenetic studies in mice by selectively activating glutamatergic neurons have demonstrated that the CnF and PPN play distinct roles in motor control: the CnF drives rapid escape behaviors, while the PPN regulates slower, exploratory movements. This functional specialization within the MLR allows animals to adapt their locomotion patterns and speed in response to environmental demands and behavioral objectives. Similar to findings in lampreys, the CnF and PPN in mice transmit motor commands to spinal effector circuits by modulating the activity of brainstem reticular formation neurons. However, they achieve this through distinct reticulospinal pathways, enabling the generation of specific behaviors. Further insights from monosynaptic rabies viral tracing reveal that the CnF and PPN integrate inputs from diverse brain regions to produce context-appropriate behaviors. For instance, glutamatergic neurons in the PPN receive signals from other midbrain structures, the basal ganglia, and medullary nuclei, whereas glutamatergic neurons in the CnF rarely receive inputs from the basal ganglia but instead are strongly influenced by the periaqueductal grey and inferior colliculus within the midbrain. These differential connectivity patterns underscore the specialized roles of the CnF and PPN in motor control, highlighting their unique contributions to coordinating locomotion. Birds exhibit exceptional flight capabilities, yet the avian MLR remains poorly understood. Comparative studies suggest that the pedunculopontine tegmental nucleus (PPTg) in birds is homologous to the mammalian PPN, which contains cholinergic neurons, while the intercollicular nucleus (ICo) or nucleus isthmi pars magnocellularis (ImC) may correspond to the CnF. These findings provide important clues for identifying the avian MLR and elucidating its role in flight control. However, functional validation through targeted experiments is urgently needed to confirm these hypotheses. Optogenetics and other advanced techniques in mice have greatly advanced MLR research, enabling precise manipulation of specific neuronal populations. Future studies should extend these methods to other species, particularly birds, to explore unique locomotor adaptations. Comparative analyses of MLR structure and function across species will deepen our understanding of the conserved and evolved features of motor control, revealing fundamental principles of locomotion regulation throughout evolution. By integrating findings from diverse species, we can uncover how the MLR has been adapted to meet the locomotor demands of different environments, from aquatic to aerial habitats.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Major depressive disorder(MDD)is a prevalent con-dition associated with substantial impairment and low remission rates.Traditional antidepressants demonstrate delayed effects,low cure rate,and inadequate therapeutic effectiveness for man-aging treatment-resistant depression(TRD).Several studies have shown that ketamine,a non-selective N-methyl-D-aspartate receptor(NMDAR)antagonist,can produce rapid and sustained antidepressant effects.Ketamine has demonstrated efficacy for reducing suicidality in TRD patients.However,the pharmaco-logical mechanism for ketamine's antidepressant effects remains incompletely understood.Previous research suggests that the an-tidepressant effects of ketamine may involve the monoaminergic,glutamatergic and dopaminergic systems.This paper provides an overview of the pharmacological mechanism for ketamine's anti-depressant effects and discuss the potential directions for future research.

Glutamate,norepinephrine,and their receptors com-prise the glutamatergic and norepinephrine systems,which mu-tually affect each other and play essential roles in mediating vari-ous neuropsychiatric diseases.This paper reviews the functions of N-methyl-D-aspartate receptor(NMDA-R)and α2-adrenergic receptor(α2-AR)and their functional crosstalk at the molecular level in brain in common neuropsychiatric diseases,which would benefit our understanding of neuropathophysiology of psychiatric diseases,drug development and optimization of clinical neuro-psychopharmacology.