ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

This paper aims to study the effect of p-cymene on mice with deficiency-cold syndrome induced by hydrocortisone and deficiency-heat syndrome induced by dexamethasone and explore the medicinal properties and mechanism of p-cymene with mild and warm nature based on the dominant characteristics of the two-way applicable conditions of mild drugs. A total of 80 KM mice were randomly divided into blank group, deficiency-cold syndrome model group, deficiency-cold syndrome + ginseng group, and deficiency-cold syndrome + low-dose and high-dose p-cymene groups, as well as blank group, deficiency-heat syndrome model group, deficiency-heat syndrome + American ginseng group, and deficiency-heat syndrome + low-dose and high-dose p-cymene groups. Hydrocortisone and dexamethasone solution were intragastrically administered for 14 consecutive days to prepare deficiency-cold syndrome and deficiency-heat syndrome models. Except for the blank group and the model group intragastrically administered with normal saline, the other groups were intragastrically administrated with drugs for 14 days. The levels of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), total cholesterol(TC), triglyceride(TG), immunoglobin G(IgG), and immunoglobin M(IgM) in serum, as well as the activity of Na~+-K~+-ATPase in liver tissue were detected. The expression of transient receptor potential melastatin 8(TRPM8), transient receptor potential vanilloid 1(TRPV1), and uncoupling protein 1(UCP1) in brown adipose tissue of deficiency-cold syndrome model after intervention with p-cymene was studied. The results showed that p-cymene could effectively improve the levels of cAMP, cAMP/cGMP, TC, IgM, and IgG in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and reduce the content of cGMP. The effects on T3, T4, and TG were not statistically significant. At the same time, p-cymene could reduce the levels of cAMP, cAMP/cGMP, and T4 in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and increase the levels of cGMP, IgM, and IgG, and it had no effect on T3, TC, and TG. In addition, p-cymene could up-regulate the expression of TRPV1 and UCP1 in brown fat of mice with deficiency-cold syndrome and down-regulate the expression of TRPM8. In summary, p-cymene could significantly regulate the syndrome indexes of mice with deficiency-cold syndrome, and some indexes of mice with deficiency-heat syndrome could be improved, but the effects on lipid metabolism and energy metabolism indexes were not obvious, indicating that the regulation effect of p-cymene on deficiency-cold syndrome model was more prominent and that the medicinal properties of p-cymene were mild and warm. The regulation of TRPV1/TRPM8/UCP1 channel expression may be the molecular biological mechanism of p-cymene with mild and warm nature affecting the energy metabolism of the body.
Animals ; Cymenes ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Disease Models, Animal ; Humans ; Cyclic AMP/metabolism* ; Monoterpenes/administration & dosage* ; Liver/metabolism* ; Cyclic GMP/metabolism* ; TRPV Cation Channels/genetics* ; Uncoupling Protein 1/genetics*

Utilizing network pharmacology, molecular docking, and cellular experimental validation, this study delved into the therapeutic efficacy and underlying mechanisms of matrine in combating senescence. Databases were utilized to predict targets related to the anti-senescence effects of matrine, resulting in the identification of 81 intersecting targets for matrine in the treatment of senescence. A protein-protein interaction(PPI) network was constructed, and key targets were screened based on degree values. Gene Ontology(GO) function and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses were performed on the key targets to elucidate the critical pathways involved in the anti-senescence effects of matrine. Molecular docking was conducted between matrine and key targets. A senescence model was established using human umbilical vein endothelial cells(HUVECs) induced with hydrogen peroxide(H_2O_2). Following treatment with varying concentrations of matrine(0.5, 1, and 2 mmol·L~(-1)), cell viability was assessed by using the CCK-8. SA-β-galactosidase staining was employed to observe the positive rate of senescent cells. Flow cytometry was utilized to measure the apoptosis rate. Real-time quantitative PCR(RT-PCR) was utilized to measure the mRNA expression of apoptosis-related cysteine peptidase 3(CASP3), albumin(ALB), glycogen synthase kinase 3β(GSK3B), CD44 molecule(CD44), and tumor necrosis factor-α(TNF-α). Western blot was performed to detect the protein expression of tumor protein p53(p53), cyclin-dependent kinase inhibitor 1A(p21), cyclin-dependent kinase inhibitor 2A(p16), and retinoblastoma tumor suppressor protein(pRb) in the senescence signaling pathway, p38 protein kinase(p38), c-Jun N-terminal kinase(JNK), and extracellular regulated protein kinases(ERK) in the mitogen-activated protein kinase(MAPK) pathway, and phosphatidylinositol 3-kinase(PI3K) and protein kinase B(Akt) in the PI3K/Akt signaling pathway. The experimental results revealed that matrine significantly increased the viability of HUVECs(P<0.05), decreased the positive rate of senescent cells and the apoptosis rate(P<0.05), and reduced the mRNA expression levels of CASP3, ALB, GSK3B, CD44, and TNF-α(P<0.05). It also inhibited the protein expression of p53, p21, p16 and pRb in the senescence signaling pathway(P<0.05), upregulated the protein expression of p-PI3K/PI3K and p-Akt/Akt(P<0.05), and downregulated the protein expression of p-p38/p38, p-JNK/JNK, and p-ERK/ERK(P<0.05). Collectively, these findings suggest that matrine exerts an inhibitory effect on HUVECs senescence, and its mechanism involves the modulation of the senescence signaling pathway, MAPK pathway, and PI3K/Akt signaling pathway to suppress cell apoptosis and inflammation.
Humans ; Matrines ; Quinolizines/chemistry* ; Alkaloids/chemistry* ; Human Umbilical Vein Endothelial Cells/cytology* ; Cellular Senescence/drug effects* ; Network Pharmacology ; Molecular Docking Simulation ; Signal Transduction/drug effects* ; Protein Interaction Maps/drug effects* ; Cell Survival/drug effects* ; Apoptosis/drug effects* ; Drugs, Chinese Herbal/pharmacology*

The prelimbic cortex (PL) plays a critical role in processing both the sensory and affective components of pain. However, the underlying molecular mechanisms remain poorly understood. In this study, we observed a reduction in hyperpolarization-activated cation current (I_h) in layer V pyramidal neurons of the contralateral PL in a mouse model of spared nerve injury (SNI). The expression of hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) channels was also decreased in the contralateral PL. Conversely, microinjection of fisetin, a partial agonist of HCN2, produced both analgesic and anxiolytic effects. Additionally, we found that cyclin-dependent kinase 5 (CDK5) was activated in the contralateral PL, where it formed a complex with HCN2 and phosphorylated its C-terminus. Knockdown of CDK5 restored HCN2 expression and alleviated both pain hypersensitivity and anxiety-like behaviors. Collectively, these results indicate that CDK5-mediated dysfunction of HCN2 in the PL underlies nerve injury-induced mechanical hypersensitivity and anxiety.
Animals ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels/metabolism* ; Hyperalgesia/metabolism* ; Cyclin-Dependent Kinase 5/metabolism* ; Neuralgia/metabolism* ; Male ; Anxiety/metabolism* ; Mice ; Potassium Channels/metabolism* ; Mice, Inbred C57BL ; Disease Models, Animal ; Pyramidal Cells/metabolism*

The accumulation of deoxyribonucleic acid (DNA) oxidative damage mediated by reactive oxygen species (ROS) is closely associated with liver diseases. 8-Oxoguanine (8-OxoG), a prevalent DNA oxidation product, plays a significant role in liver disease progression. The base excision repair (BER) pathway, comprising over 30 proteins including 8-OxoG DNA glycosylase1 (OGG1), MutY homolog (MUTYH), and MutT homolog protein 1 (MTH1), is responsible for the clearance and mismatch repair of 8-OxoG. Abnormally high levels of 8-OxoG and dysregulated expression and function of 8-OxoG repair enzymes contribute to the onset and development of liver diseases. Consequently, targeting the 8-OxoG production and repair system with agonists or inhibitors may offer a promising approach to liver disease treatment. This review summarizes the impact of 8-OxoG accumulation and dysregulated repair enzymes on various liver diseases, including viral liver disease, alcoholic liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), cholestatic liver disease (CLD), liver fibrosis, cirrhosis, and liver cancer. Additionally, we review natural constituents as potential therapeutic agents that regulate 8-OxoG production, repair enzymes, and repair system-related signal pathways in oxidative damage-induced liver diseases.
Humans ; Liver Diseases/genetics* ; Biological Products/pharmacology* ; DNA Repair/drug effects* ; Guanine/metabolism* ; Animals ; Disease Progression ; DNA Damage ; Oxidative Stress

Pulmonary arterial hypertension(PAH)is a severe disease characterized by abnormal pulmonary vascular remodeling and increased right ventricular pressure load,posing a significant threat to patient health.While some pathological mechanisms of PAH have been revealed,the deeper mechanisms of pathogenesis remain to be elucidated.In recent years,bioinformatics has provided a powerful tool for a deeper understanding of the complex mechanisms of PAH through the integration of techniques such as multi-omics analysis,artificial intelligence,and Mendelian randomization.This review focuses on the bioinformatics methods and technologies used in PAH research,summarizing their current applications in the study of disease mechanisms,diagnosis,and prognosis assessment.Additionally,it analyzes the existing challenges faced by bioinformatics and its potential applications in the clinical and basic research fields of PAH in the future.[Chinese Journal of Contemporary Pediatrics,2024,26(4):425-431]

Transmission electron microscopy(TEM)is considered as an important characterization tool for revealing morphology of materials and an indispensable strategy for studying the mechanisms of charge-discharge process in battery.TEM samples needs be less than 0.1 μm thick,which means electrodeposited materials must undergo pre-treatment processes such as focusing ion beam etching,ultra-thin slicing,or ultrasonic dispersion before they can be observed via TEM.However,such treatments cause structure changes,and what real formed in electrodes is hard to estimate.In this work,a self-interlacing film layer composed of carbon nanotubes(CNTs)was fabricated on a copper grid through blade coating.A novel TEM grid was produced by optimizing the interlacing film's thickness and covering area through adjusting the interlacing state of various concentrations of CNTs.Utilizing the novel TEM grid as the battery's positive electrode,electrode deposits were acquired and subjected to TEM analysis to generate high-definition microstructure images of the electrode surface.This process provided new insights into sample preparation for investigating the deposition/stripping mechanism in high-energy-density metal anodes.

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

Objective:To explore the value of the imaging nomogram model based on preoperative CT features of patients with small intestinal stromal tumor (SIST) in predicting pathological risk classification.Methods:This was a cohort study. The patients who were diagnosed as primary SIST by postoperative pathology in Cancer Hospital, Chinese Academy of Medical Sciences from January 2014 to October 2023 were retrospectively included. According to the modified 2008 National Institutes of Health classification criteria, the patients were divided into a pathological intermediate/high-risk group (86 cases) and a very low/low-risk group (56 cases). The features of preoperative enhanced CT images of SIST were analyzed, including tumor boundary, necrosis, intra-tumoral hemorrhage, intra-tumoral calcification, growth pattern, enhancement pattern, enhancement degree, enlarged vessels feeding or draining the mass (EVFDM), and tumor location. Patients were followed up to determine the recurrence-free survival (RFS). Univariate and multivariate logistic regression were used to screen the independent predictors of SIST with pathological medium/high-risk group. The independent predictors were combined to construct an imaging prediction model, and a nomogram was drawn. The receiver operating characteristic curve was used to evaluate the predictive efficacy of the model. The Kaplan-Meier method was used to draw the survival curve, and the log-rank test was used to compare the differences in RFS.Results:Univariate logistic regression results showed that tumor shape, necrosis, intra-tumoral hemorrhage, EVFDM, and tumor location were potentially related to medium/high-risk SIST. Multivariate logistic regression results showed that tumor shape ( OR=3.92, 95% CI 1.58-9.71, P=0.003), necrosis ( OR=4.60, 95% CI 1.91-11.09, P<0.001), and EVFDM ( OR=6.25,95% CI 1.74-22.47, P=0.005) were independent predictors of pathological intermediate/high-risk SIST. The area under the curve of the imaging predictive model combining the three predictors to predict the intermediate/high-risk SIST was 0.835 (95% CI 0.769-0.901), the sensitivity was 0.810, the specificity was 0.839, and the accuracy was 0.789. Taking the cut-off value (0.810) as the boundary value, the patients were divided into the high-risk group (74 cases) and the low-risk group (68 cases) according to the prediction results. The median RFS of the predicted high-risk group was poorer than that of the predicted low-risk group, and the difference was statistically significant ( χ2=5.20, P=0.023). Conclusions:The imaging nomogram model based on preoperative CT image features shape, necrosis, and EVFDM can effectively predict the pathological intermediate/high-risk SIST before surgery and has important predictive value for postoperative recurrence.

Tuberous sclerosis complex(TSC)is a rare genetic disease that can lead to benign dysplasia in multiple organs such as the skin, brain, eyes, oral cavity, heart, lungs, kidneys, liver, and bones. Its main symptoms include epilepsy, intellectual disabilities, skin depigmentation, and facial angiofibromas, whilst incidence is approximately 1 in 10 000 to 1 in 6000 newborns. This case presents a middle-aged woman who initially manifested with epilepsy and nodular depigmentation. Later, she developed a lower abdominal mass, elevated creatinine, and severe anemia. Based on clinical features and whole exome sequencing, the primary diagnosis was confirmed as TSC. Laboratory and imaging examinations revealed that the lower abdominal mass originated from the uterus. CT-guided biopsy pathology and surgical pathology suggested a combination of leiomyoma and abscess. With the involvement of multiple organs and various complications beyond the main diagnosis, the diagnostic and therapeutic process for this patient highlights the importance of rigorous clinical thinking and multidisciplinary collaboration in the diagnosis and treatment of rare and challenging diseases.