Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

This study aims to explore whether Naoxintong Capsules improve multiple cerebral infarctions and myocardial injury via promoting angiogenesis, thereby exerting a simultaneous treatment effect on both the brain and heart. Male SD rats were randomly divided into six groups: sham-operated group, model group, high-dose, medium-dose, and low-dose groups of Naoxintong Capsules(440, 220, and 110 mg·kg~(-1)), and nimodipine group(10.8 mg·kg~(-1)). Rat models of multiple cerebral infarctions were established by injecting autologous thrombus, and samples were collected and tested seven days after modeling. Evaluations included multiple cerebral infarction model assessments, neurological function scores, grip strength tests, and rotarod tests, so as to evaluate neuromotor functions. Morphological structures of brain and heart tissue were observed using hematoxylin-eosin(HE) staining, Nissl staining, and Masson staining. Network pharmacology was employed to screen the mechanisms of Naoxintong Capsules in improving multiple cerebral infarctions and myocardial injury. Neuronal and myocardial cell ultrastructures were observed using transmission electron microscopy. Apoptosis rate in brain neuronal cells was detected by TdT-mediated dUTP nick end labeling(TUNEL) staining, and reactive oxygen species(ROS) levels in myocardial cells were measured. Immunofluorescence was used to detect the expression of platelet endothelial cell adhesion molecule-1(CD31), antigen identified by monoclonal antibody Ki67(Ki67), hematopoietic progenitor cell antigen CD34(CD34), and hypoxia inducible factor-1α(HIF-1α) in brain and myocardial tissue. Western blot, and real-time quantitative polymerase chain reaction(RT-qPCR) were used to detect the expression of HIF-1α, vascular endothelial growth factor(VEGF), vascular endothelial growth factor receptor 2(VEGFR2), sarcoma(Src), basic fibroblast growth factor(bFGF), angiopoietin-1(Ang-1), and TEK receptor tyrosine kinase(Tie-2). Compared with the model group, the medium-dose group of Naoxintong Capsules showed significantly lower neurological function scores, increased grip strength, and prolonged time on the rotarod. Pathological damage in brain and heart tissue was reduced, with increased and more orderly arranged mitochondria in neurons and cardiomyocytes. Apoptosis in brain neuronal cells was decreased, and ROS levels in cardiomyocytes were reduced. The microvascular density and endothelial cells of new blood vessels in brain and heart tissue increased, with increased overlapping regions of CD31 and Ki67 expression. The relative protein and mRNA expression levels of HIF-1α, VEGF, VEGFR2, Src, Ang-1, Tie-2, and bFGF were elevated in brain tissue and myocardial tissue. Naoxintong Capsules may improve multiple cerebral infarctions and myocardial injury by mediating HIF-1α/VEGF expression to promote angiogenesis.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Cerebral Infarction/genetics* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Vascular Endothelial Growth Factor A/genetics* ; Capsules ; Signal Transduction/drug effects* ; Humans ; Brain/metabolism* ; Myocardium/metabolism* ; Apoptosis/drug effects*

OBJECTIVE: To screen anti-tumor drugs that improve antigen processing and presentation in acute myeloid leukemia (AML) cells. METHODS: A TCR-like or TCR mimic antibody that can specifically recognize HLA-A*0201:WT1_126-134 ( RMFPNAPYL) complex (hereafter referred to as HLA-A2:WT1) was synthesized to evaluate the function of antigen processing and presentation machinery (APM) in AML cells. AML cell line THP1 was incubated with increasing concentrations of IFN-γ, hypomethylating agents (HMA), immunomodulatory drugs (IMiD), proteasome inhibitors (PI) and γ-secretase inhibitors (GSI), followed by measuring of HLA-ABC, HLA-A2 and HLA-A2:WT1 levels by flow cytometry at consecutive time points. RESULTS: The TCR-like antibody we generated only binds to HLA-A*0201⁺WT1⁺ cells, indicating the specificity of the antibody. HLA-A2:WT1 level of THP-1 cells detected with the TCR-like antibody was increased significantly after co-incubation with IFN-γ, showing that the HLA-A2:WT1 TCR like antibody could evaluate the function of APM. Among the anti-tumor agents screened in this study, GSI (LY-411575) and HMA (decitabine and azacitidine) could significantly increase the HLA-A2:WT1 level. The IMiD lenalidomide and pomalidomide could aslo upregulate the expression of HLA-A2:WT1 complex under certain concentrations of the drugs and incubation time. As proteasome inhibitors, carfilzomib could significantly decreased the expression of HLA-A2:WT1, while bortezomib had no significant effect on HLA-A2:WT1 expression. CONCLUSION HLA-A2:WT1 TCR-like antibody can effectively reflect the APM function. Some of the anti-tumor drugs can affect the APM function and immunogenicity of tumor cells.
Humans ; Leukemia, Myeloid, Acute/immunology* ; Antineoplastic Agents/pharmacology* ; Antigen Presentation/drug effects* ; HLA-A2 Antigen/immunology* ; Receptors, Antigen, T-Cell/immunology* ; Cell Line, Tumor ; Interferon-gamma

Hepatic stellate cells (HSCs) are the primary fibrogenic cells in the liver, and their activation plays a crucial role in the development and progression of hepatic fibrosis. Here, we report that retinoid X receptor-alpha (RXRα), a unique member of the nuclear receptor superfamily, is a key modulator of HSC activation and liver fibrosis. RXRα exerts its effects by modulating calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-mediated activation of AMP-activated protein kinase-alpha (AMPKα). In addition, we demonstrate that K-80003, which binds RXRα by a unique mechanism, effectively suppresses HSC activation, proliferation, and migration, thereby inhibiting liver fibrosis in the CCl₄ and amylin liver NASH (AMLN) diet animal models. The effect is mediated by AMPKα activation, promoting mitophagy in HSCs. Mechanistically, K-80003 activates AMPKα by inducing RXRα to form condensates with CaMKKβ and AMPKα via a two-phase process. The formation of RXRα condensates is driven by its N-terminal intrinsic disorder region and requires phosphorylation by CaMKKβ. Our results reveal a crucial role of RXRα in liver fibrosis regulation through modulating mitochondrial activities in HSCs. Furthermore, they suggest that K-80003 and related RXRα modulators hold promise as therapeutic agents for fibrosis-related diseases.

Liver transplantation (LT) has become a standard treatment for end-stage liver diseases, and graft injury is intricately associated with poor prognosis. Granzyme B (GZMB) plays a vital role in natural killer (NK) cell biology, but whether NK-derived GZMB affects graft injury remains elusive. Through the analysis of single-cell RNA-sequencing data obtained from human LT grafts and the isolation of lymphocytes from mouse livers following ischemia-reperfusion injury (IRI), we demonstrated that 2NK cells with high expression of GZMB are enriched in patients and mice. Both systemically and liver-targeted depletion of NK cells led to a notable reduction in GZMB⁺ cell infiltration, subsequently resulting in diminished graft injury. Notably, the reconstitution of Il2rg ^-/- Rag2 ^-/- mice with purified Gzmb-KO NK cells demonstrated superior outcomes compared to those with wild-type NK cells. Crucially, global knockout of GZMB and pharmacological inhibition exhibited remarkable improvements in liver function in both mouse IRI and rat LT models. Moreover, a phosphorylated derivative of FDA-approved vidarabine was identified as an effective inhibitor of mouse GZMB activity by molecular dynamics, which could provide a potential avenue for therapeutic intervention. Therefore, targeting NK cell-derived GZMB during the LT process suggests potential therapeutic strategies to improve post-transplant outcomes.

Objective To explore the value of electrocardiogram in predicting culprit vessels in acute inferior myocardial infarction.Methods The clinical data of 129 patients with acute inferior myocardial infarction admitted to First Affiliated Hospital of Army Medical University from January 2015 to December 2021 were retrospectively analyzed.Patients were received coronary intervention treatment,and the culprit vessels were identified by coronary angiography.The culprit vessels during surgery were recorded.The preoperative electrocardio-gram of patients were analyzed,a new method for predicting culprit vessels in acute inferior myocardial infarction was established based on the previous researches,and the accuracies of the Fiol method,Tiala method,Huang's algorithm and new method in predicting the culprit vessels in acute inferior myocardial infarction were also counted.The predictive abilities of various methods on culprit vessels were evaluated using receiver operating characteristic(ROC)curve and the area under the curve(AUC)was calculated.Results The culprit vessels of 109 patients were the right coronary artery,16 cases were the left circumflex artery,and 4 cases were the anterior descending artery.A total of 52 patients developed clinical complications,of which the culprit vessels of 47 cases were right coronary artery and 5 cases were circumflex artery.The accuracies of the Fiol method,Tierala method,Huang's algorithm,and new method in predicting culprit vessels were 83.7%,81.4%,82.9%,and 85.3%,respectively.The ROC curve analysis showed that the Fiol method(AUC=0.941),Tierrala method(AUC= 0.945),Huang's algorithm(AUC=0.945),and new method(AUC=0.964)all had strong predictive ability for culprit vessels.Conclusion For patients with acute inferior myocardial infarction,the Fiol method,Tierala method,Huang's algorithm,and new method all have high predictive value for culprit vessels in analyzing the preoperative electrocardiogram,and the new method has a higher predictive value.

Hydrogen sulfide,as a third gas signal molecule and neurotransmitter,can play a neuroprotective role by anti-oxidative stress,anti-inflammatory response,metabolic inhibition and other mechanisms.It is of great significance for the occurrence and development of neurodegenerative diseases including Alzheimer's disease(AD)and Parkinson's disease(PD)mediated by neuroinflammation.This article reviews the research progress of hydrogen sulfide and neuroinflammation and its mediated neurodegenerative diseases,so as to provide new ideas for the treatment of neurodegenerative diseases.

Objective:To investigate the effects of Ziyin Liangxue formula combined with prednisone on immune function and the ST2/IL-33 pathway in mice with immune thrombocytopenia.Methods:In 40 BALB/c mice,32 were constructed as immune thrombocytopenia mouse models by antiplatelet serum injection.After successful modeling,the mice were randomly divided into model group,Ziyin Liangxue formula group(0.2 ml/10 g),prednisone group(0.2 ml/10 g),and Ziyin Liangxue formula+prednisone group(0.2 ml/10 g),8 mice in each group,and the other 8 mice were set as control group.The drugs were administered by gavage at the dose,and the model group and control group were given equal amounts of saline by gavage once a day for 2 weeks of continuous intervention.Blood samples and spleen tissues were collected,the peripheral platelet count was measured by automatic hematology analyzer,the pathological changes in spleen tissue was observed by HE staining,the levels of serum transforming growth factor(TGF)-β,interleukin(IL)-17,and peripheral blood thrombopoietin(TPO)were detected by enzyme-linked immunosorbent assay(ELISA),the expression of IL-33,sST2,and ST2 in spleen tissue was detected by Western blot,and the cell counts of peripheral blood Th17 and Treg were detected by flow cytometry.Results:Compared with the control group,the number of platelets,the level of TPO,TGF-β,and Treg cells were significantly decreased(P＜().05),while the level of IL-17,Thl7 cells,and the expression of IL-33,sST2,and ST2 protein were significantly increased in the model group(P＜0.01).Compared with the model group,the number of platelets,the level of TPO,TGF-β,and Treg cells were significantly increased(P＜0.05),while the level of IL-17,Th17 cells,and the expression of IL-33,sST2,and ST2 protein were significantly decreased in the Ziyin Liangxue formula+prednisone group(P＜0.01).Conclusion:Ziyin Liangxue formula+prednisone can effectively regulate Th17/Treg balance,thus effectively improve immune thrombocytopenia,and the mechanism may be related to the regulation of ST2/IL-33 signaling pathway.

AIM To rapidly screen xanthine oxidase(XOD)inhibitors from Smilax glabra Roxb.by enzyme-immobilized magnetic microspheres and LC-MS/MS,and to confirm the anti-uric acid constituents from S.glabra Roxb.METHODS The immobilized xanthine oxidase was prepared by covalent coupling with carboxyl magnetic beads as a carrier.The xanthine oxidase inhibitors in S.glabra were screened by the specific adsorption of immobilized enzyme.LC-MS/MS and standard substances were used for analysis and comparison,and the inhibitory activity and inhibition type of the screened and identified components were investigated.RESULTS The successful synthesis of immobilized xanthine oxidase was characterized by scanning electron microscopy and infrared spectroscopy.The enzyme loading was 70.50 μg/mg and the relative activity was 79.44%.Thirteen active compounds were screened from the extract of S.glabra,and eleven compounds were identified.The enzyme activity test showed that the inhibitory activites of engeletin and isoengeletin were the strongest,which was close to the positive control allopurinol.The IC50 value and inhibition type were 32.25 μg/mL,mixed inhibition,35.12 μg/mL,competitive inhibition.CONCLUSION The method is simple,rapid,accurate and suitable for directly screened active ingredients which can inhibit XOD from complex extract of traditional Chinese medicines.

Objective:The primary goal of this study is to explore the safety and effectiveness of a new modified eversion carotid endarterectomy (MECEA).Methods:This is a retrospective case series study. One hundred patients were consecutively treated with MECEA by the same operator at Department of Vascular Surgery,Peking Union Medical College Hospital from January 2019 to December 2023. There were 77 males and 23 females. The age was (66.0±8.6)years (range: 39 to 85 years). Twenty-four (24.0%) patients were symptomatic with the degree of carotid stenosis over 50%,76 patients (76.0%) were asymptomatic with the degree of stenosis over 70%. All these patients meet the indication of carotid endarterectomy. The main difference between MECEA and traditional eversion carotid endarterectomy was the anterior,lateral,and posterior walls of the internal carotid artery were incised obliquely from the origin of the internal carotid artery toward the common carotid artery,leaving the wall of internal carotid artery intact at the bifurcation. The surgical process,cardiovascular and cerebrovascular complications and other surgical complications were recorded. The incidences of complications,restenosis of intraoperative target lesions and re-intervention were collected during follow-up.Results:All procedures were performed successfully under general anesthesia. The total operation time was (36.5±10.1)minutes (range: 22 to 65 minutes),and carotid clamping time was (15.0±6.3)minutes (range: 7 to 31 minutes). One patient (1.0%) occurred postoperative cerebrovascular accident,1 patient (1.0%) developed cerebral hyperperfusion syndrome (CHS),and another 1 patient (1.0%) suffered myocardial infarction. All these patients were recovered after medical treatment within a week. The follow-up time( M(IQR)) was 24 (28) months (range: 6 to 62 months). Two patients (2.0%) were reported to have hemodynamically significant restenosis within 2 years,with one patient requiring intervention. No patient suffered from ipsilateral ischemic stroke. Conclusions:MECEA is a safe and effective surgical method of treating carotid artery stenosis. This method can reduce carotid clamping time and lowers the risk of ischemic stroke. Meantime,it preserves the integrity of the adventitia at the bifurcation of carotid artery,reduces the chance of restenosis. Moreover,it might be helpful to prevent postoperative CHS due to reducing damage to the carotid body and carotid sinus nerve.