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.

BACKGROUND:Ca2+expression in astrocytes has been found to be closely related to cognitive function,and the Ca2+signaling pathway regulated by inositol 1,4,5-trisphosphate receptors(IP3R2)and ryanodine receptor(RYR)2 receptors has become a hot spot in the study of cognitive disorder-related diseases. OBJECTIVE:To investigate the expression of Ca2+signals mediated by IP3R2 and RYR2 in hippocampal astrocytes in animal models of delayed encephalopathy after acute carbon monoxide poisoning,and to explore the possible pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning. METHODS:C57BL mice with qualified cognitive function were selected by Morris water maze experiment and randomly divided into control group and experimental group.An animal model of delayed encephalopathy after acute carbon monoxide poisoning was established by static carbon monoxide inhalation in the experimental group,and the same amount of air was inhaled in the control group.Behavioral and neuronal changes,astrocyte specific marker glial fibrillary acidic protein,IP3R2,RYR2 receptor and Ca2+concentration in astrocytes of the two groups were detected using Morris water maze,hematoxylin-eosin staining,western blot,immunofluorescence double labeling and Ca2+fluorescence probe at 21 days after modeling. RESULTS AND CONCLUSION:In the Morris water maze,the escape latency of the experimental group was significantly longer than that of the control group(P<0.05).Hematoxylin-eosin staining results showed that in the experimental group,the number of hippocampal pyramidal cells decreased,the cell structure was disordered,and the nucleus was broken and dissolved.Immunofluorescence results showed that IP3R2 and RYR2 were co-expressed with glial fibrillary acidic protein in the hippocampus,and the expressions of IP3R2,RYR2 and glial fibrillary acidic protein were up-regulated in the hippocampus of the experimental group(P<0.05).Western blot analysis showed that the expressions of IP3R2,RYR2,and glial fibrillary acidic protein in the hippocampus of the experimental group were increased(P<0.05).Ca2+concentration in hippocampal astrocytes increased significantly in the experimental group(P<0.05).To conclude,astrocytes may affect Ca2+signals by mediating IP3R2 and RYR2 receptors,then impair the cognitive function of mice with carbon monoxide poisoning,and eventually lead to delayed encephalopathy after acute carbon monoxide poisoning.

ObjectiveThis paper aims to investigate the potential molecular biological mechanism of Buyang Huanwu Tongfeng decoction in treating hyperuricemia and gouty arthritis by network pharmacology and molecular docking technology and preliminarily verify the mechanism through animal experiments. MethodsThe active ingredients and targets in the Buyang Huanwu Tongfeng decoction were obtained by the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP） and ETCM databases. The DisGeNET and GeneCards databases were utilized to acquire disease targets associated with hyperuricemia and gouty arthritis. These disease targets were then intersected with drug targets to identify key targets. The R language ClusterProfiler package and Python were employed for conducting gene ontology（GO） enrichment analysis and Kyoto encyclopedia of genes and genomes（KEGG） enrichment analysis. The regulatory network diagram of the drug-key target-function-pathway was visualized using Cytoscape 3.9.1 software， and the protein-protein interaction （PPI） network for key targets was depicted. Finally， the hub gene was determined through topological analysis. Auto Dock， PyMOL， and other software were used for molecular docking to explore the possible therapeutic mechanism of Buyang Huanwu Tongfeng decoction for hyperuricemia and gouty arthritis. In animal experiments， a composite rat model of hyperuricemia induced by intraperitoneal injection of oteracil potassium combined with gouty arthritis induced by the modified Coderre method was established. Through hematoxylin-eosin（HE） staining， uric acid test， enzyme linked immunosorbent assay（ELISA）， Western blot， and real-time polymerase chain reaction（Real-time PCR）， the molecular mechanism and key targets of Buyang Huanwu Tongfeng decoction for treating hyperuricemia and gouty arthritis were observed. ResultsAfter screening and removing duplicate values， 76 active ingredients and 15 key targets were finally obtained. GO enrichment analysis yielded that the treatment of hyperuricemia and gouty arthritis with Buyang Huanwu Tongfeng decoction was significantly associated with acute inflammatory response， astrocyte activation， regulation of interleukin （IL）-8 production， nuclear receptor activity， and binding of growth factor receptor. KEGG pathway enrichment analysis obtained that the key target genes were significantly associated with the IL-17 signaling pathway， advanced glycosylation end/receptor of advanced glycation endproducts（AGE/RAGE） signaling pathway， anti-inflammatory， and other pathways. PPI network indicated that albumin（ALB）， peroxisome proliferator-activated receptor-γ （PPAR-γ）， IL-6， IL-1β， and C-reactive protein（CRP） were the key protein targets. The molecular docking results showed that ALB had the strongest binding force with beta-carotene （β-carotene）. Biochemical results showed that blood uric acid decreased in the Buyang Huanwu Tongfeng decoction groups. HE staining results showed that the low-dose （7.76 g·kg^-1·d^-1）， medium-dose （15.53 g·kg^-1·d^-1）， and high-dose （31.05 g·kg^-1·d^-1） groups of Buyang Huanwu Tongfeng decoction had different degrees of remission， and the remission of the high-dose group was the most obvious. Fibroblastic tissue hyperplasia in synovial joints accompanied with inflammatory cell infiltration， as well as inflammatory cell infiltration in renal tissue of the high-dose group was significantly reduced， followed by the medium-dose and low-dose groups， and the expression of ALB， PPAR-γ， IL-6， IL-1β， and CRP was down-regulated to different degrees. ConclusionBy regulating the targets such as ALB， PPAR-γ， IL-6， IL-1β， and CRP， inhibiting the PPAR-γ/nuclear transcription factor （NF）-κB pathway， and reducing AGEs/RAGE-mediated inflammation， Buyang Huanwu Tongfeng decoction exerts anti-inflammatory and analgesic effects and activates blood circulation and diuresis in the treatment of hyperuricemia and gouty arthritis.

Yinyang Gongji Pills have the effects of strengthening the body resistance to eliminate pathogenic factors, removing stasis, and reducing swelling, which is a commonly used traditional Chinese medicine(TCM) formula for treating intestinal accumulation. A real-world, registered, and single-arm clinical trial was conducted to observe the clinical efficacy and safety of Yinyang Gongji Pills combined with capecitabine in the treatment of advanced colorectal cancer and analyze the clinical characteristics of the patients. A total of 60 patients with advanced colorectal cancer who refused or could not tolerate standard treatment of western medicine were included in the study. They were treated with Yinyang Gongji Pills combined with capecitabine until disease progression or intolerable adverse events occurred. The main observation indicators were progression-free survival(PFS) and safety. The treatment effects of the patients under different baseline characteristics were analyzed. The clinical trial has found that the median PFS of all enrolled patients was 7.3 months, with 30.1% of patients having a PFS exceeding 12.0 months. Layered analysis showed that the median PFS of patients with the onset site being the colon and rectum were respectively 8.4 and 4.7 months. The median PFS of patients with high, medium, and low tumor burden were respectively 7.0, 4.7, and 10.8 months. The median PFS of patients with wild-type and mutant-type RAS/BRAF were respectively 7.9 and 6.9 months. The median PFS of patients with KPS scores ≥80 and ≤70 were respectively 7.9 and 6.5 months. The median PFS of patients treated with Yinyang Gongji Pills for ≥6, 3-6, and ≤3 months were respectively 8.0, 5.2, and 4.2 months. The median PFS of patients with spleen, kidney, liver, and lung syndrome differentiation in TCM were respectively 8.3, 6.7, 7.3, and 5.6 months. The median PFS of patients with TCM pathological factors including phlegm, dampness, and blood stasis were respectively 7.0, 7.3, and 6.5 months. Common adverse reactions include anemia, decreased white blood cells, decreased appetite, fatigue, and hand foot syndrome, with incidence rates being respectively 44.2%, 34.6%, 42.3%, 32.7%, and 17.3%. The results showed that the combination of Yinyang Gongji Pills and capecitabine demonstrated potential clinical efficacy and good safety in this study. The patients have clinical characteristics such as low tumor burden, onset site at the colon, KPS scores ≥ 80, long duration of oral TCM, and TCM syndrome differentiation including spleen or liver.
Humans ; Capecitabine/adverse effects* ; Colorectal Neoplasms/mortality* ; Drugs, Chinese Herbal/adverse effects* ; Male ; Middle Aged ; Female ; Aged ; Adult ; Treatment Outcome

In this study, Saccharomyces cerevisiae R0 was used as the chassis cell to synthesize oleanolic acid from scratch through the heterologous expression of β-amyrin synthase(β-AS) from Glycyrrhiza uralensis, cytochrome P450 enzyme CYP716A154 from Catharanthus roseus, and cytochrome P450 reductase AtCPR from Arabidopsis thaliana. The engineered strain R1 achieved shake flask titres of 5.19 mg·L~(-1). By overexpressing enzymes in the pentose phosphate pathway(PPP)(ZWF1, GND1, TKL1, and TAL), the NADH kinase gene in the mitochondrial matrix(POS5), truncated 3-hydroxy-3-methylglutaryl-CoA reductase(tPgHMGR1) from Panax ginseng, and farnesyl diphosphate synthase gene(SmFPS) from Salvia miltiorrhiza, the precursor supply and intracellular reduced nicotinamide adenine dinucleotide phosphate(NADPH) supply were enhanced, resulting in an 11.4-fold increase in squalene yield and a 3.6-fold increase in oleanolic acid yield. Subsequently, increasing the copy number of the heterologous genes tPgHMGR1, β-AS, CYP716A154, and AtCPR promoted the metabolic flow towards the final product, oleanolic acid, and increased the yield by three times. Shake flask fermentation data showed that, by increasing the copy number, precursor supply, and intracellular NADPH supply, the final engineered strain R3 could achieve an oleanolic acid yield of 53.96 mg·L~(-1), which was 10 times higher than that of the control strain R1. This study not only laid the foundation for the green biosynthesis of oleanolic acid but also provided a reference for metabolic engineering research on other pentacyclic triterpenoids in S. cerevisiae.
Oleanolic Acid/biosynthesis* ; Saccharomyces cerevisiae/metabolism* ; Industrial Microbiology ; Microorganisms, Genetically-Modified/metabolism* ; Plants/enzymology* ; Fermentation ; Metabolic Engineering

Many triterpenoid compounds have been successfully heterologously synthesized in Saccharomyces cerevisiae. To increase the yield of triterpenoids, various metabolic engineering strategies have been developed. One commonly applied strategy is to enhance the supply of precursors, which has been widely used by researchers. Squalene, as a precursor to triterpenoid biosynthesis, plays a crucial role in the synthesis of these compounds. This study primarily investigates the effect of different squalene levels in chassis strains on the synthesis of triterpenoids(oleanolic acid and ursolic acid), and the underlying mechanisms are further explored using real-time quantitative PCR(qPCR) analysis. The results demonstrate that the chassis strain CB-9-5, which produces high levels of squalene, inhibits the synthesis of oleanolic acid and ursolic acid. In contrast, chassis strains with moderate to low squalene production, such as Y8-1 and CNPK, are more conducive to the synthesis of oleanolic acid and ursolic acid. The qPCR analysis reveals that the expression levels of ERG1, βAS, and CrCYP716A154 in the oleanolic acid-producing strain CB-OA are significantly lower than those in the control strains C-OA and Y-OA, suggesting that high squalene production in the chassis strains suppresses the transcription of certain genes, leading to a reduced yield of triterpenoids. Our findings indicate that when constructing S. cerevisiae strains for triterpenoid production, chassis strains with high squalene content may suppress the expression of certain genes, ultimately lowering their production, whereas chassis strains with moderate squalene levels are more favorable for triterpenoid biosynthesis.
Squalene/analysis* ; Saccharomyces cerevisiae/genetics* ; Triterpenes/metabolism* ; Metabolic Engineering ; Oleanolic Acid/biosynthesis* ; Ursolic Acid

This study aims to explore the mechanism of lung and gut protection by Tanreqing Capsules on the mice infected with influenza virus based on "the lung-gut axis". A total of 110 C57BL/6J mice were randomized into control group, model group, oseltamivir group, and low-and high-dose Tanreqing Capsules groups. Ten mice in each group underwent body weight protection experiments, and the remaining 12 mice underwent experiments for mechanism exploration. Mice were infected with influenza virus A/Puerto Rico/08/1934(PR8) via nasal inhalation for the modeling. The lung tissue was collected on day 3 after gavage, and the lung tissue, colon tissue, and feces were collected on day 7 after gavage for subsequent testing. The results showed that Tanreqing Capsules alleviated the body weight reduction and increased the survival rate caused by PR8 infection. Compared with model group, Tanreqing Capsules can alleviate the lung injury by reducing the lung index, alleviating inflammation and edema in the lung tissue, down-regulating viral gene expression at the late stage of infection, reducing the percentage of neutrophils, and increasing the percentage of T cells. Tanreqing Capsules relieved the gut injury by restoring the colon length, increasing intestinal lumen mucin secretion, alleviating intestinal inflammation, and reducing goblet cell destruction. The gut microbiota analysis showed that Tanreqing Capsules increased species diversity compared with model group. At the phylum level, Tanreqing Capsules significantly increased the abundance of Firmicutes and Actinobacteria, while reducing the abundance of Bacteroidota and Proteobacteria to maintain gut microbiota balance. At the genus level, Tanreqing Capsules significantly increased the abundance of unclassified＿f＿Lachnospiraceae while reducing the abundance of Bacteroides, Eubacterium, and Phocaeicola to maintain gut microbiota balance. In conclusion, Tanreqing Capsules can alleviate mouse lung and gut injury caused by influenza virus infection and restore the balance of gut microbiota. Treating influenza from the lung and gut can provide new ideas for clinical practice.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Lung/metabolism* ; Mice, Inbred C57BL ; Capsules ; Orthomyxoviridae Infections/virology* ; Gastrointestinal Microbiome/drug effects* ; Male ; Humans ; Female ; Influenza A virus/physiology* ; Influenza, Human/virology*

Sishen Pills and its separated prescriptions are classic prescriptions of traditional Chinese medicine to treat intestinal diseases. In this study, a high-performance liquid chromatography-electrospray ionization tandem mass spectrometry(HPLC-ESI-MS/MS) technology was used to identify the components of Sishen Pills, Ershen Pills, and Wuweizi Powder. The positive and negative ion sources of electrospray ionization were simultaneously collected by mass spectrometry. A total of 11 effective components were detected in Sishen Pills, with four effective components detected in Ershen Pills and eight effective components detected in Wuweizi Powder, respectively. To explore the effects of Sishen Pills and its separated prescriptions on the human intestinal flora, an in vitro anaerobic fermentation model was established, and the human intestinal flora was incubated with Sishen Pills, Ershen Pills, and Wuweizi Powder in vitro. The 16S rDNA sequencing technology was used to analyze the changes in the intestinal flora. The results showed that compared with the control group, Sishen Pills, and its separated prescriptions could decrease the intestinal flora abundance and increase the Shannon index after fermentation. The abundance of Bifidobacterium was significantly increased in the Sishen Pills and Ershen Pills groups. However, the abundance of Lactobacillus, Weissella, and Pediococcus was significantly increased in the Wuweizi Powder group. After fermentation for 12 h, the pH of the fermentation solution of three kinds of liquids with feces gradually decreased and was lower than that of the control group. The decreasing amplitude in the Wuweizi Powder group was the most obvious. The single-bacteria fermentation experiments further confirmed that Sishen Pills and Wuweizi Powder had inhibitory effects on Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis, and the antibacterial activity of Wuweizi Powder was stronger than that of Sishen Pills. Both Sishen Pills and Ershen Pills could promote the growth of Lactobacillus brevis, and Ershen Pills could promote the growth of Bifidobacterium adolescentis. This study provided a more sufficient theoretical basis for the clinical application of Sishen Pills and its separated prescriptions.
Humans ; Gastrointestinal Microbiome/drug effects* ; Drugs, Chinese Herbal/chemistry* ; Fermentation/drug effects* ; Bacteria/drug effects* ; Chromatography, High Pressure Liquid ; Tandem Mass Spectrometry ; Intestines/microbiology*

OBJECTIVES: To explore the association between GPSM2 expression level and gastric cancer progression and analyze the functional pathways and action mechanism of GPSM2. METHODS: We analyzed GPSM2 expression levels in gastric cancer tumors based on data from the GEPIA database and the clinical data of 109 patients. Public databases enrichment analysis were used to assess the impact of GPSM2 expression level on survival outcomes and the functional pathways and action mechanism of GPSM2. We further observed the effects of GPSM2 knockdown and overexpression on proliferation, migration and apoptosis of MGC803 cells using CCK-8 assay, colony formation assay, flow cytometry and immunoblotting and on the growth of MGC803 cell xenografts in nude mice. RESULTS: Bioinformatic analysis and immunohistochemical staining of the clinical specimens both revealed high GPSM2 expressions in gastric cancer (P<0.01). A high GPSM2 expression was significantly correlated with T3-4 stages, N2-3 stages, a carcinoembryonic antigen (CEA) level ≥5 μg/L, and a carbohydrate antigen (CA) 19-9 level ≥37 kU/L (P<0.05). Cox regression analysis identified high GPSM2 expression as an independent risk factor affecting 5-year survival of the patients (P<0.05). Gene ontology (GO) analysis suggested that GPSM2 was involved in cell cycle regulation. In MGC803 cells, GPSM2 overexpression significantly promoted cell proliferation and G1/S transition and xenograft growth in nude mice. KEGG pathway enrichment analysis indicated that GPSM2 executed its biological functions by regulating the p53 signaling pathway, which was confirmed by the results of immunoblotting experiments showing suppression of p53 signaling pathway activity in GPSM2-over expressing MGC803 cells. CONCLUSIONS GPSM2 is highly expressed in gastric cancer to affect patient prognosis by promoting tumor cell proliferation and G1/S transition possibly via inhibiting the p53 pathway.
Stomach Neoplasms/metabolism* ; Humans ; Cell Proliferation ; Prognosis ; Animals ; Mice, Nude ; Cell Line, Tumor ; Mice ; Apoptosis ; Tumor Suppressor Protein p53/metabolism* ; Cell Movement

OBJECTIVES: To investigate the effect of monotropein on motor function recovery of mice with spinal cord injury (SCI) and explore the underlying mechanism. METHODS: Forty-five adult female C57BL/6 mice were randomized equally into sham operation group, SCI group, and SCI group with daily intraperitoneal monotropein injection. The mice in the former two groups received daily saline injections. Motor function of the mice was evaluated using BMS scores, slant plate test, and footprint analyses. Pathological changes and neuronal counts in the spinal cord were observed using HE, LFB, and Nissl staining. The biological functions of monotropein were explored using GO and KEGG enrichment analyses. NeuN/cleaved caspase-3 immunofluorescence assay and Western blotting were used to detect neuronal apoptosis in the spinal cord of the mice. In cultured HT22 cells, the effect of monotropein on TNF-α-induced cell apoptosis was evaluated using TUNEL staining and Western blotting. In monotropein-treated HT22 cells and SCI mice, the changes in the PI3K/AKT pathway were examined, and the effect of a PI3K/AKT pathway activator (IGF-1) on HT22 cell apoptosis and motor function recovery of SCI mice were observed. RESULTS: SCI mice with monotropein treatment showed significantly improved motor functions with reduced SCI areas and increased myelin retention and neuron counts in the spinal cord. Bioinformatics analysis suggested a role of PI3K/AKT signaling pathway in mediating the anti-apoptotic effects of monotropein. In SCI mice, monotropein obviously reduced apoptotic neurons, decreased expressions of cleaved caspase-3 and Bax and increased Bcl-2 expression in the spinal cord. In HT22 cells, monotropein significantly inhibited TNF-α-induced apoptosis and PI3K/AKT pathway activation. Treatment with IGF-1 obviously increased apoptosis of HT22 cells and exacerbated locomotor dysfunction in SCI mice. CONCLUSIONS Monotropein promotes motor function recovery in SCI mice by reducing neuronal apoptosis possibly by inhibiting the PI3K/AKT signaling pathway.
Animals ; Spinal Cord Injuries/metabolism* ; Apoptosis/drug effects* ; Signal Transduction/drug effects* ; Mice, Inbred C57BL ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Female ; Phosphatidylinositol 3-Kinases/metabolism* ; Neurons/pathology* ; Recovery of Function