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.

Aim To evaluate the effect of hyperoside/chitosan-nanoparticles(Hyp-NPs)on bone marrow mesenchymal stem cells(BMSCs)in vitro cell experi-ments and the underlying mechanism,and to conduct in vivo animal experiments to investigate the synergistic effect of Hyp-NPs and BMSCs on repairing endometrial damage in rats.Methods BMSCs were identified by flow cytometry.Hyp-NPs were prepared by ion crosslinking method,characterized and evaluated by laser particle size analyzer and transmission electron microscopy.The effects of different concentrations of Hyp-NPs on the migration of BMSCs were evaluated by scratch assay and immunofluorescence.NRF2 lentivir-us vector was constructed to explore the mechanism of Hyp-NPs on BMSCs.In animal experiments,Hyp-NPs loaded with BMSCs were co-transplanted into the uter-ine cavity of a rat model of endometrial injury.HE,Masson,IHC,TUNEL,and ELISA experiments were used to systematically evaluate the repair effect and pregnancy function of the composite formulation on rat endometrial injury from multiple aspects and angles,including general pathology,fibrosis,receptivity,cell proliferation,angiogenesis,stem cell recruitment,and inflammation of the endometrium.Results BMSCs were successfully isolated and cultured.Hyp-NPs with high stability and small particle size were successfully prepared.Scratch experiments indicated that Hyp-NPs could promote the migration of BMSCs.By successfully constructing a lentiviral NRF2 vector and oxidative damage model for BMSCs,immunofluorescence experi-ments showed that Hyp-NPs could regulate the biologi-cal axis of BMSCs by activating NRF2.Animal experi-ments showed that the synergistic administration of Hyp-NPs and BMSCs could increase endometrial thick-ness and glandular quantity,promote stem cell homing through anti-fibrotic,anti-apoptotic,and anti-inflam-matory effects,and restore pregnancy function in rats with endometrial injury.Conclusion The synergistic administration of Hyp-NPs and BMSCs could repair en-dometrial injury.

The blood-brain barrier (BBB) plays a crucial role in maintaining the homeostasis of the brain's internal environment, which poses challenges to the treatment of central nervous system diseases. Drug carriers can aid in the delivery of therapeutic agents across the BBB to exert their pharmacological effects. The article reviewed the pathways for drug delivery across the BBB, the intracerebral fate and the classification of drug carriers and focuses on the functions and characteristics of liposomes, exosomes, apoptotic bodies, cell-penetrating peptides, and cell-targeting peptides. The review will provide an outlook on the future and challenge of research in the field of drug delivery across the BBB.

Objectives: . Reactive oxygen species in the stria vascularis (SV) of the cochlea may be involved in the pathogenesis of sensorineural hearing loss. However, the effects of oxidative stress on SV endothelial cells (SV-ECs) remain largely unknown, and no feasible in vitro cell culture model exists for the functional study of SV-ECs. Methods: . We isolated primary SV-ECs from the SV of neonatal mice. The apoptosis-reducing effects of fibronectin in SV-ECs cultured with serum-free medium were determined using β-galactosidase staining and flow cytometry. SV-ECs incubated in serum-free medium were treated with various H2O2 concentrations to evaluate the effects of H2O2 on their viability. The secretome of SV-ECs treated with or without H2O2 (100 μM or 500 μM) was analyzed using high-resolution mass spectrometry. The function of the SV-EC secretome was evaluated by a macrophage assay. Results: . We successfully isolated and characterized the SV-ECs. Treatment with H2O2 at concentrations up to 500 μM for 2 hours and further incubation with serum-free medium in plates precoated with fibronectin showed no significant effect on apoptosis. Compared to the control SV-ECs, the amount of differential proteins in the secretome of SV-ECs stimulated with 500 μM H2O2 was much higher than in those treated with 100 μM H2O2. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses suggested that the proteins differentially expressed in SV-ECs treated with 500 μM H2O2 were involved in the regulation of multiple signaling pathways and cellular processes. The secretome of H2O2-stimulated SV-ECs exhibited significant pro-inflammatory effects on macrophages. Conclusion . We successfully established an in vitro serum-free culture method, identified the differential proteins released by oxidative stress-induced ECs and their functions, and revealed the pro-inflammatory effects of the secretome of H2O2-stimulated SV-ECs. Therefore, SV-ECs might elicit immunoregulatory effects on bystander cells in the microenvironment of oxidative stress-induced cochlea, especially cochlear macrophages.

Tumor brings great threat to human public health. In recent years, incidence rate and mortality of tumor were rapidly increased in the world. Anti-tumor therapies have undergone the development of cytotoxic therapy, targeted therapy, and immunotherapy. Among them, tumor immunotherapy is rapidly developed and becomes an important anti-tumor therapy in recent years, although it also brings some related side effects. Tumor microenvironment (TME) is composed of immune cells, vascular vessels, fibroblasts, the extracellular matrix, etc. TME significantly affects the efficacy of immunotherapy. Macrophages in the TME are named as tumor associated macrophages (TAMs). Recently, increasing studies have shown that TAMs play an important role in the regulation of tumor immunity, especially in tumor immune surveillance and immune escape. Currently, more and more anti-tumor immunotherapy strategies targeting TAMs are at the development stage. Based on the important role of TAMs in the TME and their potential as therapeutic targets in tumor immunotherapy, we first reviewed the subtypes and functions of TAMs, as well as the roles of TAMs in tumors. Furthermore, we summarized the research progress on anti-tumor strategies targeting TAMs and the current status of drug targeting TAMs. The current review will provide new ideas and novel insights for tumor immunotherapy.

OBJECTIVE: Clinical characteristics and outcome in COVID-19 with brucellosis patients has not been well demonstrated, we tried to analyze clinical outcome in local and literature COVID-19 cases with brucellosis before and after recovery. METHODS: We retrospectively collected hospitalization data of comorbid patients and prospectively followed up after discharge in Heilongjiang Infectious Disease Hospital from January 15, 2020 to April 29, 2022. Demographics, epidemiological, clinical symptoms, radiological and laboratory data, treatment medicines and outcomes, and follow up were analyzed, and findings of a systematic review were demonstrated. RESULTS: A total of four COVID-19 with brucellosis patients were included. One patient had active brucellosis before covid and 3 patients had nonactive brucellosis before brucellosis. The median age was 54.5 years, and all were males (100.0%). Two cases (50.0%) were moderate, and one was mild and asymptomatic, respectively. Three cases (75.0%) had at least one comorbidity (brucellosis excluded). All 4 patients were found in COVID-19 nucleic acid screening. Case C and D had only headache and fever on admission, respectively. Four cases were treated with Traditional Chinese medicine, western medicines for three cases, no adverse reaction occurred during hospitalization. All patients were cured and discharged. Moreover, one case (25.0%) had still active brucellosis without re-positive COVID-19, and other three cases (75.0%) have no symptoms of discomfort except one case fell fatigue and anxious during the follow-up period after recovery. Conducting the literature review, two similar cases have been reported in two case reports, and were both recovered, whereas, no data of follow up after recovery. CONCLUSION These cases indicate that COVID-19 patients with brucellosis had favorable outcome before and after recovery. More clinical studies should be conducted to confirm our findings.
Female ; Humans ; Male ; Middle Aged ; Brucellosis ; COVID-19 ; Retrospective Studies ; SARS-CoV-2 ; Treatment Outcome ; Case Reports as Topic

OBJECTIVE: To investigate the efficacy and safety of plerixafor combined with granulocyte colony-stimulating factor (G-CSF) in mobilizing peripheral blood hematopoietic stem cells in patients with lymphoma. METHODS: The clinical data of lymphoma patients who received autologous hematopoietic stem cell mobilization using plerixafor combined with G-CSF from January 2019 to December 2021 were retrospectively analyzed. The patients received 3 kinds of mobilization regimens: front-line steady-state mobilization, preemptive intervention, and recuse mobilization. The acquisition success rate, excellent rate of collection, and incidence of treatment-related adverse reaction were counted. The influence of sex, age, disease remission status, bone marrow involvement at diagnosis, chemotherapy lines, number of chemotherapy, platelet count and number of CD34⁺ cells on the day before acquisition in peripheral blood on the collection results were analyzed to identify the risk factors associated with poor stem cell collection. RESULTS: A total of 43 patients with lymphoma were enrolled, including 7 cases who received front-line steady-state mobilization, 19 cases who received preemptive intervention, and 17 cases who received recuse mobilization. The overall acquisition success rate was 58.1% (25/43) after use of plerixafor combined with G-CSF, and acquisition success rate of front-line steady-state mobilization, preemptive intervention, and recuse mobilization was 100%, 57.9%(11/19), and 41.2%(7/17), respectively. The excellent rate of collection was 18.6%(8/43). A total of 15 patients experienced mild to moderate treatment-related adverse reactions. The number of CD34⁺ cells < 5 cells/μl in peripheral blood on the day before collection was an independent risk factor affecting stem cell collection. CONCLUSIONS Plerixafor combined with G-CSF is a safe and effective mobilization regimen for patients with lymphoma. The number of CD34⁺ cells in peripheral blood on the day before collection is an predictable index for the evaluation of stem cell collection.
Humans ; Antigens, CD34/metabolism* ; Granulocyte Colony-Stimulating Factor/therapeutic use* ; Hematopoietic Stem Cell Mobilization/methods* ; Hematopoietic Stem Cell Transplantation ; Heterocyclic Compounds/therapeutic use* ; Lymphoma/drug therapy* ; Multiple Myeloma/drug therapy* ; Retrospective Studies ; Transplantation, Autologous

Humans ; Sinus of Valsalva ; Death, Sudden, Cardiac/etiology* ; Coronary Stenosis/complications*

This study investigated the effect of puerarin on human umbilical vein endothelial cells (HUVEC) injured with hydrogen peroxide (H₂O₂). HUVEC were divided into three groups: a control group, a model group (H₂O₂ 400 μmol·L^-1) and a puerarin-treated group (3, 10, 30 and 100 μmol·L^-1). HUVEC were cultured with varied concentration of puerarin for 2 h and treated with H₂O₂ for another 24 h. Cell proliferation was detected by a CCK-8 assay. The mitochondrial membrane potential was measured by a JC-1 fluorescent probe. A transwell chamber assay was adopted to observe cell migration ability. Mitochondrial respiratory function was measured in a two-chamber titration injection respirometer (Oxygraph-2k). The expression of interleukin-1β (IL-1β), interleukin-18 (IL-18) and tumor necrosis factor-α (TNF-α) was detected by quantitative real-time PCR. The expression of pyroptosis-mediated proteins, including cleaved-cysteinyl aspartate-specific proteinase-1 (caspase-1), N-gasdermin D (N-GSDMD), NOD-like receptor protein 3 (NLRP3) and purinergic ligand-gated ion channel 7 receptor (P2X7R) was detected by Western blot. The results show that 400 μmol·L^-1 H₂O₂ treatment for 24 h causes obvious damage to HUVEC. Compared with the model group, puerarin protected against cellular injury in a dose-dependent manner, with the greatest effect at a dose of 30 and 100 μmol·L^-1. Puerarin significantly decreased the mitochondrial membrane potential and improved mitochondrial function. Puerarin inhibited cell migration induced by H₂O₂, suppressed the expression of IL-1β, IL-18 and TNF-α, and down-regulated the pyroptosis-mediated protein. These changes are statistically significant (P < 0.05). These findings demonstrate that puerarin has a protective effect against H₂O₂-induced oxidative damage of HUVEC by inhibiting the migration of HUVEC cells. The mechanism may be related to improved mitochondrial respiratory function and inhibition of pyroptosis.

OBJECTIVE: To investigate the effect of biflavonoid 4'-O-methylochnaflavone (MF) on palmitic acid-induced endothelial dysfunction in rat cavernous endothelial cells (RCECs). METHODS: The isolated RCECs were commercially available and randomly divided into four groups: normal+BSA group (NC group), palmitic acid (PA) group, MF group, and icariside Ⅱ (ICA Ⅱ) group. The protein expression levels of protein kinase B (PKB/AKT) and endothelial nitric oxide synthase (eNOS) in each group were evaluated via Western blotting. The differences in the intracellular nitric oxide of RCECs treated by MF or ICA Ⅱ were detected by DAF-FM DA that served as a nitric oxide fluorescent probe. Effects of MF and ICA Ⅱ on cell proliferation of PA-stimulated RCECs were determined via CCK-8 assay. RESULTS: The content of nitric oxide in RCECs was significantly increased after the treatment of MF and ICA Ⅱ in comparison with the NC group (P < 0.05). Moreover, compared with ICA Ⅱ group, MF demonstrated a more obvious effect in promoting nitric oxide production (P < 0.05). Compared with the NC group, the expression levels of eNOS and AKT in the PA group were significantly decreased, indicating that a model for simulating the high-fat environment in vitro was successfully constructed (P < 0.05). Meanwhile, the intervention of MF and ICA Ⅱ could effectively increase the expression of eNOS and AKT, suggesting that MF and ICA Ⅱ could promote the recovery of endothelial dysfunction caused by high levels of free fatty acids (P < 0.05). The results of CCK-8 assays showed that PA could significantly reduce the proli-feration ability of RCECs (P < 0.05). Furthermore, the decreased cell viability induced by PA was significantly elevated by treatment with ICA Ⅱ and MF (P < 0.05). CONCLUSION In RCECs, MF and ICA Ⅱ could effectively increase the content of nitric oxide. The down-regulation of the expression of proteins associated with the AKT/eNOS pathway after PA treatment revealed that this pathway was involved in the development of endothelial dysfunction, which could be effectively reversed by MF and ICA Ⅱ. In addition, the cell proliferation ability was significantly decreased following PA treatment, but MF and ICA Ⅱ could restore the above changes. Overall, biflavonoid MF has an obvious repairing effect on PA-stimulated endothelial dysfunction.
Animals ; Biflavonoids/pharmacology* ; Cells, Cultured ; Endothelial Cells/metabolism* ; Nitric Oxide/pharmacology* ; Nitric Oxide Synthase Type III/pharmacology* ; Palmitic Acid/pharmacology* ; Phosphorylation ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats ; Signal Transduction ; Sincalide/pharmacology*