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 circadian clock plays a critical role in regulating various physiological processes, including gene expression, metabolic regulation, immune response, and the sleep-wake cycle in living organisms. Post-translational modifications (PTMs) are crucial regulatory mechanisms to maintain the precise oscillation of the circadian clock. By modulating the stability, activity, cell localization and protein-protein interactions of core clock proteins, PTMs enable these proteins to respond dynamically to environmental and intracellular changes, thereby sustaining the periodic oscillations of the circadian clock. Different types of PTMs exert their effects through distincting molecular mechanisms, collectively ensuring the proper function of the circadian system. This review systematically summarized several major types of PTMs, including phosphorylation, acetylation, ubiquitination, SUMOylation and oxidative modification, and overviewed their roles in regulating the core clock proteins and the associated pathways, with the goals of providing a theoretical foundation for the deeper understanding of clock mechanisms and the treatment of diseases associated with circadian disruption.
Protein Processing, Post-Translational/physiology* ; Circadian Rhythm/physiology* ; Humans ; Animals ; CLOCK Proteins/physiology* ; Circadian Clocks/physiology* ; Phosphorylation ; Acetylation ; Ubiquitination ; Sumoylation

The study was conducted to investigate the mechanism of Xinyang Tablets( XYP) in modulating the fat mass and obesity-associated protein(FTO)/N6-methyladenosine(m6A) signaling pathway to ameliorate ventricular remodeling in heart failure(HF). A mouse model of HF was established by transverse aortic constriction(TAC). Mice were randomized into sham, model, XYP(low, medium, and high doses), and positive control( perindopril) groups(n= 10). From day 3 post-surgery, mice were administrated with corresponding drugs by gavage for 6 consecutive weeks. Following the treatment, echocardiography was employed to evaluate the cardiac function, and RT-qPCR was employed to determine the relative m RNA levels of key markers, including atrial natriuretic peptide( ANP), B-type natriuretic peptide( BNP), β-myosin heavy chain(β-MHC), collagen type I alpha chain(Col1α), collagen type Ⅲ alpha chain(Col3α), alpha smooth muscle actin(α-SMA), and FTO. The cardiac tissue was stained with Masson's trichrome and wheat germ agglutinin(WGA) to reveal the pathological changes. Immunohistochemistry was employed to detect the expression levels of Col1α, Col3α, α-SMA, and FTO in the myocardial tissue. The m6A modification level in the myocardial tissue was measured by the m6A assay kit. An H9c2 cell model of cardiomyocyte injury was induced by angiotensin Ⅱ(AngⅡ), and small interfering RNA(siRNA) was employed to knock down FTO expression. RT-qPCR was conducted to assess the relative m RNA levels of FTO and other genes associated with cardiac remodeling. The m6A modification level was measured by the m6A assay kit, and Western blot was employed to determine the phosphorylated phosphatidylinositol 3-kinase(p-PI3K)/phosphatidylinositol 3-kinase(PI3K) and phosphorylated serine/threonine kinase(p-Akt)/serine/threonine kinase(Akt) ratios in cardiomyocytes. The results of animal experiments showed that the XYP treatment significantly improved the cardiac function, reduced fibrosis, up-regulated the m RNA and protein levels of FTO, and lowered the m6A modification level compared with the model group. The results of cell experiments showed that the XYP-containing serum markedly up-regulated the m RNA level of FTO while decreasing the m6A modification level and the p-PI3K/PI3K and p-Akt/Akt ratios in cardiomyocytes. Furthermore, FTO knockdown reversed the protective effects of XYP-containing serum on Ang Ⅱ-induced cardiomyocyte hypertrophy. In conclusion, XYP may ameliorate ventricular remodeling by regulating the FTO/m6A axis, thereby inhibiting the activation of the PI3K/Akt signaling pathway.
Animals ; Ventricular Remodeling/drug effects* ; Heart Failure/physiopathology* ; Signal Transduction/drug effects* ; Mice ; Male ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Mice, Inbred C57BL ; Humans ; Adenosine/analogs & derivatives* ; Myocytes, Cardiac/metabolism* ; Disease Models, Animal

Cardiac fibrosis(CF) is a cardiac pathological process characterized by excessive deposition of extracellular matrix(ECM). When the heart is damaged by adverse stimuli, cardiac fibroblasts are activated and secrete a large amount of ECM, leading to changes in cardiac fibrosis, myocardial stiffness, and cardiac function declines and accelerating the development of heart failure. There is a close relationship between heart yin deficiency and cardiac fibrosis, which have similar pathogenic mechanisms. Heart Yin deficiency, characterized by insufficient Yin fluids, causes the heart to lose its nourishing function, which acts as the initiating factor for myocardial dystrophy. The deficiency of body fluids leads to stagnation of blood flow, resulting in blood stasis and water retention. Blood stasis and water retention accumulate in the heart, which aligns with the pathological manifestation of excessive deposition of ECM, as a tangible pathogenic factor. This is an inevitable stage of the disease process. The lingering of blood stasis combined with water retention eventually leads to the generation of heat and toxins, triggering inflammatory responses similar to heat toxins, which continuously stimulate the heart and cause the ultimate outcome of CF. Considering the syndrome of heart Yin deficiency, traditional Chinese medicine capable of nourishing Yin, activating blood, and promoting urination can reduce myocardial cell apoptosis, inhibit fibroblast activation, and lower the inflammation level, showing significant advantages in combating CF.
Humans ; Fibrosis/drug therapy* ; Animals ; Yin Deficiency/metabolism* ; Myocardium/metabolism* ; Medicine, Chinese Traditional ; Drugs, Chinese Herbal/therapeutic use*

This study investigates the effect and underlying mechanism of Guizhi Tongluo Tablets(GZTL) in treating atherosclerosis(AS) in a mouse model. Apolipoprotein E-knockout(ApoE~(-/-)) mice were randomly assigned to the following groups: model, high-, medium-, and low-dose GZTL, and atorvastatin(ATV), and age-matched C57BL/6J mice were selected as the control group. ApoE~(-/-) mice in other groups except the control group were fed with a high-fat diet for the modeling of AS and administrated with corresponding drugs via gavage for 8 weeks. General conditions, signs of blood stasis, and body mass of mice were monitored. Aortic plaques and their stability were assessed by hematoxylin-eosin, Masson, and oil red O staining. Serum levels of total cholesterol(TC), triglycerides(TG), and low-density lipoprotein cholesterol(LDL-C) were measured by biochemical assays, and those of interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6) were determined via enzyme-linked immunosorbent assay. Apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL). Single-cell RNA sequencing(scRNA-seq) was employed to analyze the differential expression of CD72hi macrophages(CD72hi-Mφ) in the aortas of AS patients and mice. The immunofluorescence assay was employed to visualize CD72hi-Mφ expression in mouse aortic plaques, and real-time fluorescence quantitative PCR was utilized to determine the mRNA levels of IL-1β, TNF-α, and IL-6 in the aorta. The results demonstrated that compared with the control group, the model group exhibited significant increases in body mass, aortic plaque area proportion, necrotic core area proportion, and lipid deposition, a notable decrease in collagen fiber content, and an increase in apoptosis. Additionally, the model group showcased elevated serum levels of TC, TG, LDL-C, IL-1β, TNF-α, and IL-6, alongside marked upregulations in the mRNA levels of IL-1β, TNF-α, and IL-6 in the aorta. In comparison with the model group, the GZTL groups and the ATV group showed a reduction in body mass, and the medium-and high-dose GZTL groups and the ATV group demonstrated reductions in aortic plaque area proportion, necrotic core area proportion, and lipid deposition, an increase in collagen fiber content, and a decrease in apoptosis. Furthermore, the treatment goups showcased lowered serum levels of TC, TG, LDL-C, IL-1β, TNF-α, and IL-6. The data of scRNA-seq revealed significantly elevated CD72hi-Mφ signaling in carotid plaques of AS patients compared with that in the normal arterial tissue. Animal experiments confirmed that CD72hi-Mφ expression, along with several pro-inflammatory cytokines, was significantly upregulated in the aortas of AS mice, which were downregulated by GZTL treatment. In conclusion, GZTL may alleviate AS by inhibiting CD72hi-Mφ activity.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Atherosclerosis/immunology* ; Mice ; Mice, Inbred C57BL ; Macrophages/immunology* ; Male ; Humans ; Apolipoproteins E/genetics* ; Tablets ; Tumor Necrosis Factor-alpha/genetics* ; Apoptosis/drug effects* ; Interleukin-1beta/genetics* ; Interleukin-6/genetics* ; Disease Models, Animal ; Mice, Knockout

Geniposidic acid(GA), a natural iridoid, exists in the roots, stems, leaves, flowers, bark, fruits, and seeds of medicinal plants of Rubiaceae, Eucommiaceae, and Plantaginaceae. Modern pharmacological studies have revealed that GA has multiple pharmacological activities, including organ-protective, anti-inflammatory, antioxidative, anti-osteoporosis, anti-neurodegenerative, and anti-cardiovascular effects. GA can enhance cell/organism defenses by upregulating key anti-inflammatory and antioxidant cytokines, while downregulating key node proteins in pro-inflammatory signaling pathways such as AhR and TLR4/MyD88, thereby exerting pharmacological effects such as organ protection. Pharmacokinetic investigations have suggested that after oral administration, GA can be distributed in multiple organs(kidney, liver, heart, spleen, lung, etc.). In addition, the pharmacokinetic behavior of GA could be significantly altered under disease conditions, as demonstrated by a marked increase in systematic exposure. This article comprehensively summarizes the reported pharmacological activities and mechanisms and systematically analyzes the pharmacokinetic characteristics and key parameters of GA, with the aim of providing a theoretical basis and scientific reference for the precise clinical application of GA-related Chinese patent medicines, as well as for the investigation and development of innovative drugs based on GA.
Humans ; Drugs, Chinese Herbal/chemistry* ; Animals ; Iridoid Glucosides/chemistry* ; Plants, Medicinal/chemistry* ; Anti-Inflammatory Agents/pharmacology*

Objective:To study the changes in skeletal muscle and serum nutritional indicators during concurrent chemoradiotherapy in cervical cancer patients,and to evaluate their correlation with short-term efficacy and long-term prognosis. Methods:A retrospective analysis was conducted on 114 patients with cervical cancer who underwent radical concurrent chemoradiotherapy in the Department of Oncology,Nanjing Drum Tower Hospital from February 2019 to February 2023. All patients underwent a treatment regimen comprising external beam radiation (EBRT),internal radiation,and concurrent chemotherapy. Serum nutritional data of the patients were collected before radiotherapy,one week,two weeks and five weeks after the onset of radiotherapy. CT images of the patients at the time of simulation and about five weeks after the onset of radiotherapy were imported into the Pinnacle 39.10 planning system,and the skeletal muscle index (SMI) of the third lumbar vertebra (L3) were calculated for each patients. The changes of the serum nutritional indicators of the patients prior to and post EBRT were analyzed statistically. The patients are categorized into two groups according to the baseline SMI:a sarcopenic group consisting of 35 cases and a non-sarcopenic group comprising 79 cases. The therapeutic outcomes between the two groups were compared,and logistic analysis of the relevant factors affecting the occurrence of sarcopenia during radiotherapy was conducted. The survival curves were drawn using Kaplan-Meier method and disease-free survival (DFS) between the two groups was compared using Log Rank test. We used Cox univariate and multivariate regression analysis to identify prognostic factors related to DFS. Results:The serum nutritional indicators of the patient at one week,two weeks,and five weeks after the beginning of EBRT were significantly lower than those before radiotherapy (P<0.05). The SMI from the CT images of simulation at five weeks after the onset of radiotherapy was significantly lower than that before radiotherapy (P<0.001). There was a significant correlation between hemoglobin levels prior to radiotherapy and incidence of sarcopenia during radiotherapy (P=0.046). There was no significant difference in efficacy between the two groups at the end of EBRT (P>0.05). At the end of radiotherapy,the complete response (CR) rate of the non-sarcopenia group was significantly higher than that of the sarcopenia group (P=0.040). However,the objective response rate (ORR) and disease control rate (DCR) of both groups at the end of radiotherapy were 100％. The 2-year DFS of the sarcopenia group and the non-sarcopenia group were 66.7％ and 85.5％,respectively,and the difference was statistically significant (P=0.016). Only four patients died during the 2-year follow-up,so OS was not reached. Baseline SMI,serum squamous cell antigen levels prior to radiotherapy,and degree of bone marrow suppression were three independent prognostic factors affecting DFS in the patients. Conclusion:Cervical cancer patients experience significant nutritional loss during chemoradiotherapy,and baseline SMI is significantly correlated with short-term efficacy and long-term prognosis and can serve as a predictive marker for patients with cervical cancer receiving chemoradiotherapy.

Aim To establish NCI-H446/EP for small cell lung cancer resistant cells resistant to cisplatin and etoposide, and to evaluate their biological characteristics and multidrug resistance. Methods Nude mice were subcutaneously inoculated with NCI-H446 cells of SCLC to construct an in vivo model of xenograft tumor, and were given first-line EP regimen treatment for SCLC, inducing drug resistance in vivo, and stripping tumor tissue in vitro culture to obtain drug-resistant cells. The resistance coefficient, cell doubling time, cell cycle distribution, expression of multidrug resistance gene (MDR1), and drug resistance-related protein were detected in vitro, and the drug resistance to cisplatin and etoposide in vivo were verified. Results Mice with NCI-H446 tumors acquired resistance after eight weeks' EP regimen treatment, and the drug-resistant cell line NCI-H446/EP was obtained by isolation and culture in vitro. The resistance factors of this cell line to cisplatin, etoposide, SN38 and doxorubicin were 12.01, 18.36, 65.4 and 10.12, respectively. Compared with parental cells, the proportion of NCIH446/EP cells in Q

In recent years,the prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKP)infection has become a global public health issue.Ceftazidime/avibactam(CAZ/AVI)has been approved as a novel antimicrobial agent for the treatment of healthcare-associated pneumonia/ventilator-associated pneumonia,bloodstream infection,infection after kidney transplantation,and severe infection combined with liver cirrhosis.However,the use of CAZ/AVI has also led to the emergence of drug-resistant strains.The major mechanisms of drug-resistance include over-expression of blaKPC gene,mutation of β-lactamase and amino acids at key sites,changes in cell permeability caused by loss of membrane porin,and over-expression of efflux pump.This article reviews the research progress of CAZ/AVI in the treatment of CRKP infection,providing reference for clinical diagnosis and treatment.