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

Most patients with differentiated thyroid cancer have a good prognosis after radioiodine-131 therapy,but a small number of patients are insensitive to radioiodine-131 therapy and even continue to develop disease.At present,some targeted drugs can improve progression-free survival in patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC),such as sorafenib and levatinib,have been approved for the treatment of RAIR-DTC.However,due to the presence of primary and acquired drug resistance,drug efficacy in these patients is unsatisfactory.This review introduces the acquired drug resistance mechanism of sorafenib in the regulation of mitogen-activated protein kinase(MAPK)and phosphatidylinositol-3-kinase(PI3K)pathways and proposes related treatment strategies,in order to provide a reference for similar drug resistance mechanism of sorafenib and effective treatment of RAIR-DTC.

Objective Human papillomavirus(HPV)is a detriment virus to human health,because it can cause malignant tumors.HPV vaccine has been developed and plays an important role in preventing a range of diseases caused by HPV.HPV vaccine as a primary prevention measure,has demonstrated excellent protective efficacy and safety in preventing HPV-related infection and cervical cancer.This article summarizes the application of preventive HPV vaccine and its safety,and provides reference for the widespread vaccination of HPV vaccine in China.

Objective To investigate the effect of Porphyromonas gingivalis(Pg)infection on immune escape of oesophageal cancer cells and the role of YTHDF2 and Fas in this regulatory mechanism.Methods We examined YTHDF2 and Fas protein expressions in esophageal squamous cell carcinoma(ESCC)tissues with and without Pg infection using immunohistochemistry and in Pg-infected KYSE150 cells using Western blotting.The interaction between YTHDF2 and Fas was investigated by co-immunoprecipitation(Co-IP).Pg-infected KYSE150 cells with lentivirus-mediated YTHDF2 knockdown were examined for changes in expression levels of YTHDF2,cathepsin B(CTSB),Fas and FasL proteins,and the effect of E64(a cathepsin inhibitor)on these proteins were observed.After Pg infection and E64 treatment,KYSE150 cells were co-cultured with human peripheral blood mononuclear cells(PBMCs),and the expressions of T cell-related effector molecules were detected by flow cytometry.Results ESCC tissues and cells with Pg infection showed significantly increased YTHDF2 expression and lowered Fas expression.The results of Co-IP demonstrated a direct interaction between YTHDF2 and Fas.In Pg-infected KYSE150 cells with YTHDF2 knockdown,the expression of CTSB was significantly reduced while Fas and FasL expressions were significantly increased.E64 treatment of KYSE150 cells significantly decreased the expression of CTSB without affecting YTHDF2 expression and obviously increased Fas and FasL expressions.Flow cytometry showed that in Pg-infected KYSE150 cells co-cultured with PBMCs,the expressions of Granzyme B and Ki67 were significantly decreased while PD-1 expression was significantly enhanced.Conclusion Pg infection YTHDF2-dependently regulates the expression of Fas to facilitate immune escape of esophageal cancer and thus promoting cancer progression,suggesting the key role of YTHDF2 in regulating immune escape of esophageal cancer.

Objective To investigate the effect of Porphyromonas gingivalis(Pg)infection on immune escape of oesophageal cancer cells and the role of YTHDF2 and Fas in this regulatory mechanism.Methods We examined YTHDF2 and Fas protein expressions in esophageal squamous cell carcinoma(ESCC)tissues with and without Pg infection using immunohistochemistry and in Pg-infected KYSE150 cells using Western blotting.The interaction between YTHDF2 and Fas was investigated by co-immunoprecipitation(Co-IP).Pg-infected KYSE150 cells with lentivirus-mediated YTHDF2 knockdown were examined for changes in expression levels of YTHDF2,cathepsin B(CTSB),Fas and FasL proteins,and the effect of E64(a cathepsin inhibitor)on these proteins were observed.After Pg infection and E64 treatment,KYSE150 cells were co-cultured with human peripheral blood mononuclear cells(PBMCs),and the expressions of T cell-related effector molecules were detected by flow cytometry.Results ESCC tissues and cells with Pg infection showed significantly increased YTHDF2 expression and lowered Fas expression.The results of Co-IP demonstrated a direct interaction between YTHDF2 and Fas.In Pg-infected KYSE150 cells with YTHDF2 knockdown,the expression of CTSB was significantly reduced while Fas and FasL expressions were significantly increased.E64 treatment of KYSE150 cells significantly decreased the expression of CTSB without affecting YTHDF2 expression and obviously increased Fas and FasL expressions.Flow cytometry showed that in Pg-infected KYSE150 cells co-cultured with PBMCs,the expressions of Granzyme B and Ki67 were significantly decreased while PD-1 expression was significantly enhanced.Conclusion Pg infection YTHDF2-dependently regulates the expression of Fas to facilitate immune escape of esophageal cancer and thus promoting cancer progression,suggesting the key role of YTHDF2 in regulating immune escape of esophageal cancer.

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.