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.

In a healthy human, the airway mucus forms a thin, protective liquid layer covering the surface of the respiratory tract. It comprises a complex blend of mucin, multiple antibacterial proteins, metabolic substances, water, and electrolytes. This mucus plays a pivotal role in the lungs' innate immune system by maintaining airway hydration and capturing airborne particles and pathogens. However, heightened mucus secretion in the airway can compromise ciliary clearance, obstruct the respiratory tract, and increase the risk of pathogen colonization and recurrent infections. Consequently, a thorough exploration of the mechanisms driving excessive airway mucus secretion is crucial for establishing a theoretical foundation for the eventual development of targeted drugs designed to reduce mucus production. Across a range of lung diseases, excessive airway mucus secretion manifests with unique characteristics and regulatory mechanisms, all intricately linked to mucin. This article provides a comprehensive overview of the characteristics and regulatory mechanisms associated with excessive airway mucus secretion in several prevalent lung diseases.
Humans ; Mucus/metabolism* ; Mucins/physiology* ; Lung Diseases/metabolism* ; Respiratory Mucosa/metabolism* ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Asthma/physiopathology* ; Cystic Fibrosis/physiopathology* ; Mucociliary Clearance/physiology*

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*

Repeated transcranial magnetic stimulation (rTMS) is one of the commonly used brain stimulation techniques. In order to investigate the effects of rTMS on the excitability of different types of neurons, this study is conducted to investigate the effects of rTMS on the cognitive function of mice and the excitability of hippocampal glutaminergic neurons and gamma-aminobutyric neurons from the perspective of electrophysiology. In this study, mice were randomly divided into glutaminergic control group, glutaminergic magnetic stimulation group, gamma-aminobutyric acid energy control group, and gamma-aminobutyric acid magnetic stimulation group. The four groups of mice were injected with adeno-associated virus to label two types of neurons and were implanted optical fiber. The stimulation groups received 14 days of stimulation and the control groups received 14 days of pseudo-stimulation. The fluorescence intensity of calcium ions in mice was recorded by optical fiber system. Behavioral experiments were conducted to explore the changes of cognitive function in mice. The patch-clamp system was used to detect the changes of neuronal action potential characteristics. The results showed that rTMS significantly improved the cognitive function of mice, increased the amplitude of calcium fluorescence of glutamergic neurons and gamma-aminobutyric neurons in the hippocampus, and enhanced the action potential related indexes of glutamergic neurons and gamma-aminobutyric neurons. The results suggest that rTMS can improve the cognitive ability of mice by enhancing the excitability of hippocampal glutaminergic neurons and gamma-aminobutyric neurons.
Animals ; Mice ; Hippocampus/cytology* ; Transcranial Magnetic Stimulation ; Neurons/physiology* ; Male ; Cognition/physiology* ; gamma-Aminobutyric Acid/metabolism* ; Action Potentials/physiology*

OBJECTIVE: To investigate the short-term efficacy and safety of low-dose venetoclax combined with CHG (cytarabine+homoharringtonine+G-CSF) priming regimen in patients with acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS) ineligible for intensive chemotherapy. METHODS: The data of 14 patients with AML or high-risk MDS admitted to the department of hematology/oncology of the First Hospital of Tsinghua University and 2 cooperative institutions from July 2022 to August 2023 were retrospectively analyzed. All the patients were treated with low-dose venetoclax combined with CHG priming regimen and the early induction (one course) efficacy and adverse reactions were observed. RESULTS: Among the 14 patients, 10 were males and 4 were females, with a median age of 69.5 (46-83) years. After 1 cycle of induction chemotherapy, the complete remission (CR) rate was 64.3% (9/14) and overall response rate (ORR) was 78.6% (11/14). Among the 10 patients with adverse prognosis according to cytogenetics and molecular genetics, the CR rate was 50.0% (5/10), and ORR was 70.0% (7/10). In 7 patients with TP53 mutation, the CR rate was 42.9% (3/7) and ORR was 71.4% (5/7). In the 6 patients with complex karyotype, CR rate was 33.3% (2/6) and ORR was 66.7% (4/6). While the CR rate and ORR of 8 non-complex karyotype patients were both 87.5% (7/8), and the difference in CR rate between patients with complex karyotype and non-complex karyotype was statistically significant ( P < 0.05). The adverse reactions of chemotherapy were tolerable, without early treatment-related deaths. CONCLUSION Low-dose venetoclax combined with CHG priming regimen can be used as an effective treatment for AML and high-risk MDS patients who are ineligible for intensive chemotherapy, and it is safe and worthy of clinical application.
Humans ; Leukemia, Myeloid, Acute/drug therapy* ; Aged ; Male ; Female ; Sulfonamides/therapeutic use* ; Middle Aged ; Myelodysplastic Syndromes/drug therapy* ; Bridged Bicyclo Compounds, Heterocyclic/therapeutic use* ; Aged, 80 and over ; Retrospective Studies ; Cytarabine/administration & dosage* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Homoharringtonine/therapeutic use*

The liver performs multiple life-sustaining functions. Hepatic diseases, including hepatitis, cirrhosis, and hepatoma, pose significant health and economic burdens globally. Along with the advances in nanotechnology, mesoporous silica nanoparticles (MSNs) exhibiting diversiform size and shape, distinct morphological properties, and favorable physico-chemical features have become an ideal choice for drug delivery systems and inspire alternative thinking for the management of hepatic diseases. Initially, we introduce the physiological structure of the liver and highlight its intrinsic cell types and correlative functions. Next, we detail the synthesis methods and physicochemical properties of MSNs and their capacity for controlled drug loading and release. Particularly, we discuss the interactions between liver and MSNs with respect to the passive targeting mechanisms of MSNs within the liver by adjusting their particle size, pore diameter, surface charge, hydrophobicity/hydrophilicity, and surface functionalization. Subsequently, we emphasize the role of MSNs in regulating liver pathophysiology, exploring their value in addressing liver pathological states, such as tumors and inflammation, combined with multi-functional designs and intelligent modes to enhance drug targeting and minimize side effects. Lastly, we put forward the problems, challenges, opportunities, as well as clinical translational issues faced by MSNs in the management of liver diseases.

Protein tyrosine phosphatases (PTPs, EC 3.1.3.48) are key regulators of cellular processes, with the catalytic activity attributed to the conserved motif (H/V)CX₅R(S/T), where cysteine and arginine residues are critical. Previous studies revealed that alternative splicing of extracellular phosphatase mRNA precursors in Metarhizium anisopliae generated two distinct transcripts, with the longer sequence containing a novel HCPTPMLS motif resembling PTP signatures but lacking the arginine residue. To identify the novel signature motif and characterize its enzymatic properties, we heterologously expressed and purified both proteins in Pichia pastoris and comprehensively characterized their enzymatic properties. The protein containing the HCPTPMLS motif (designated as L-protein) exhibited the highest activity at pH 5.5 and a strong preference for pTyr substrates. Its phosphatase activity was inhibited by Ag⁺, Zn²⁺, Cu²⁺, molybdate, and tungstate, but enhanced by Ca²⁺ and EDTA. AcP101 (lacking HCPTPMLS) showed the maximal activity at pH 6.5 and a strong preference toward pNPP (P < 0.05), with the activity inhibited by NaF and tartrate, but enhanced by Mg²⁺ and Mn²⁺. Functional analysis confirmed that the L-protein retained the PTP activity despite the absence of arginine in its signature motif, while AcP101 functioned as an acid phosphatase. This study provides the first functional validation of an arginine-deficient PTP motif, expanding the definition of PTP signature motifs and offering new insights for phosphatase classification.
Metarhizium/genetics* ; Protein Tyrosine Phosphatases/chemistry* ; Amino Acid Motifs ; Recombinant Proteins/biosynthesis* ; Amino Acid Sequence ; Pichia/metabolism* ; Fungal Proteins/chemistry* ; Substrate Specificity ; Saccharomycetales

Background Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants widely distributed in the environment. Epidemiological studies have shown that PFAS exposure is closely associated with liver dysfunction and an increased risk of liver cancer. Some animal and cell experiments have also revealed its hepatotoxicity and potential carcinogenicity; however, the related carcinogenic mechanism has not yet been fully elucidated. Objective To explore the potential molecular mechanism of PFAS-induced liver cancer, identify the key causal genes, and specifically evaluate the causal association and expression changes of KMT2C in this process, as well as the binding stability between KMT2C and PFAS, and to provid a theoretical basis for mechanistic studies and molecular target discovery in PFAS-related liver cancer. Methods Toxicity prediction was performed on six representative PFAS. Potential target genes of PFAS were identified by integrating results from SwissTargetPrediction, STITCH, and TargetNet databases. Liver cancer-related genes were retrieved from GeneCards, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Database (TTD). The intersection of PFAS targets and liver cancer-related genes was used to obtain core genes. A compound-gene-disease regulatory network was constructed, and a protein–protein interaction network was established using STRING database. A core gene network was visualized based on node degree values. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to explore biological functions and enriched signaling pathways. Subsequently, two-sample Mendelian randomization was employed to assess potential causal relationships between candidate genes and hepatocellular carcinoma, enabling the identification of key genes. Molecular docking analysis using AutoDock was conducted to evaluate the binding stability between KMT2C and PFAS, and TCGA data were used to validate the differential expression of KMT2C between hepatocellular carcinoma and adjacent normal tissues. Results PFAS exhibited multisystem toxicity and posed significant risks of liver injury and carcinogenesis. A total of 266 PFAS target genes and 2923 liver cancer-related genes were identified, with 61 intersecting genes obtained. The enrichment analysis revealed that these intersecting genes were primarily involved in epigenetic regulation, nuclear receptor signaling pathways, and apoptosis-related pathways including TGF-β FoxO and Notch, suggesting their roles in diverse tumor-related biological processes. The two-sample Mendelian randomization results showed a significant negative causal association between KMT2C and hepatocellular carcinoma (OR=0.68, P <0.05). The molecular docking results demonstrated that all tested PFAS exhibited favorable binding to the KMT2C protein, with binding energies below –5.0 kcal·mol⁻¹. KMT2C was significantly upregulated in hepatocellular carcinoma tissues (unpaired P=0.025; paired P=8.38 × 10⁻⁴). Conclusion The KMT2C protein is found to stably bind with all six PFAS, exhibiting strong structural affinity. A causal relationship is identified between KMT2C and the development of hepatocellular carcinoma. TCGA data indicate that KMT2C is significantly upregulated in hepatocellular carcinoma tissues, and it may serve as a key regulatory target in PFAS-related liver cancer.

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.