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.

ObjectiveTo explore the role and potential mechanism of circulating glutamate in enhancing insulin sensitivity by aerobic exercise. This research may provide a novel strategy for preventing metabolic diseases through precise exercise interventions. MethodsTo investigate the effects of elevated circulating glutamate on insulin sensitivity and its potential mechanisms, 18 male C57BL/6 mice aged 6 to 8 weeks were randomly divided into 3 groups: a control group (C), a group receiving 500 mg/kg glutamate supplementation (M), and a group receiving 1 000 mg/kg glutamate supplementation (H). The intervention lasted for 12 weeks, with treatments administered 6 d per week. Following the intervention, an insulin tolerance test (ITT) and a glucose tolerance test (GTT) were conducted. Circulating glutamate levels were measured using a commercial kit, and the activity of the skeletal muscle InsR/IRS1/PI3K/AKT signaling pathway was analyzed via Western blot. To further investigate the role of circulating glutamate in enhancing insulin sensitivity through aerobic exercise, 30 male C57BL/6 mice were randomly assigned to 3 groups: a control group (CS), an exercise intervention group (ES), and an exercise combined with glutamate supplementation group (EG). The ES group underwent treadmill-based aerobic exercise, while the EG group received glutamate supplementation at a dosage of 1 000 mg/kg in addition to aerobic exercise. The intervention lasted for 10 weeks, with sessions occurring 6 d per week, and the same procedures were followed afterward. To further elucidate the mechanism by which glutamate modulates the InsR/IRS1/PI3K/AKT signaling pathway, C2C12 myotubes were initially subjected to graded glutamate treatment (0, 0.5, 1, 3, 5, 10 mmol/L) to determine the optimal concentration for cellular intervention. Subsequently, the cells were divided into 3 groups: a control group (C), a glutamate intervention group (G), and a glutamate combined with MK801 (an NMDA receptor antagonist) intervention group (GK). The G group was treated with 5 mmol/L glutamate, while the GK group received 50 μmol/L MK801 in addition to 5 mmol/L glutamate. After 24 h of intervention, the activity of the InsR/IRS1/PI3K/AKT signaling pathway was analyzed using Western blot. ResultsCompared to the mice in group C, the circulating glutamate levels, the area under curve (AUC) of ITT, and the AUC of GTT in the mice of group H were significantly increased. Additionally, the expression levels of p-InsRβ, IRS1, p-AKT, and p-mTOR proteins in skeletal muscle were significantly downregulated. Compared to the mice in group CS, the circulating glutamate levels, the AUC of ITT, and the AUC of GTT in the mice of group ES were significantly reduced. Additionally, the expression levels of p-InsRβ, IRS1, p-AKT, and p-mTOR proteins in skeletal muscle of group ES mice were significantly upregulated. There were no significant changes observed in the mice of group EG. Compared to the cells in group 0 mmol/L, the expression levels of p-InsRβ, p-IRS1, p-PI3K, and p-AKT proteins in cells of group 5 mmol/L were significantly downregulated. Compared to the cells in group C, the expression levels of p-InsRβ, p-IRS1, p-PI3K, and p-AKT proteins in the cells of group G were significantly downregulated. No significant changes were observed in the cells of group GK. ConclusionLong-term aerobic exercise can improve insulin sensitivity by lowering circulating levels of glutamate. This effect may be associated with the upregulation of the InsR/IRS1/AKT signaling pathway activity in skeletal muscle. Furthermore, glutamate can weaken the activity of the InsR/IRS1/PI3K/AKT signaling pathway in skeletal muscle, potentially by binding to NMDAR expressed in skeletal muscle.

Helicobacter pylori (Hp) is currently classified as a class I carcinogen that can cause gastric cancer, research in recent years on how Hp infection causes the occurrence and progression of gastric cancer has attracted much attention. As the primary virulence factor of Hp, cytotoxicity-associated gene A (CagA) has been extensively studied and reported to function as a key excreted toxin for Hp to induce gastric infection, colonization and promote inflammatory-carcinogenic transformation of host cells. Patients infected with CagA-positive strains have a higher risk of developing tumors compared to those infected with CagA-negative strains. Based on previous studies, this article further elaborates on the import process, biological activity, and related molecular mechanisms of virulence protein CagA in the occurrence and development of gastric cancer induced by Hp infection.

In the central nervous system (CNS), the myelin sheath, a specialized membrane structure that wraps around axons, is formed by oligodendrocytes through a highly coordinated spatiotemporal developmental program. The process begins with the directed differentiation of neural precursor cells into oligodendrocyte precursor cells (OPCs), followed by their migration, proliferation, differentiation, and maturation, ultimately leading to the formation of a multi-segmental myelin sheath structure. Recent single-cell sequencing research has revealed that this process involves the temporal regulation of over 200 key genes, with a regulatory network composed of transcription factors such as Sox10 and Olig2 playing a central role. The primary function of the myelin sheath is to accelerate nerve signal transmission and protect nerve fibers from damage. Its insulating properties not only increase nerve conduction speed by 50-100 times but also ensure the long-term functional integrity of the nervous system by maintaining axonal metabolic homeostasis and providing mechanical protection. The pathological effects of myelin sheath injury exhibit a cascade amplification pattern: acute demyelination leads to action potential conduction block, while chronic lesions may cause axonal damage and neuronal death in severe or long-term cases, ultimately resulting in irreversible neurological dysfunction with neurodegenerative characteristics. Multiple sclerosis (MS) is a neurodegenerative disease characterized by chronic inflammatory demyelination of the CNS. Clinically, the distribution of lesions in MS exhibits spatial heterogeneity, which is closely related to differences in the regenerative capacity of oligodendrocytes within the local microenvironment. Emerging evidence suggests that astrocytes form a dynamic “neural-immune-metabolic interface” and play a multidimensional regulatory role in myelin development and regeneration by forming heterogeneous populations composed of different subtypes. During embryonic development, astrocytes induce the targeted differentiation of OPCs in the ventricular region through the Wnt/β-catenin pathway. In the mature stage, they secrete platelet-derived growth factor AA (PDGF-AA) to establish a chemical gradient that guides the precise migration of OPCs along axonal bundles. Notably, astrocytes also provide crucial metabolic support by supplying energy substrates for high-energy myelin formation through the lactate shuttle mechanism. In addition, astrocytes play a dual role in myelin regulation. During the acute injury phase, reactive astrocytes establish a triple defense system within 72 h: upregulating glial fibrillary acidic protein (GFAP) to form scars that isolate lesions, activating the JAK-STAT3 regeneration pathway in oligodendrocytes via leukemia inhibitory factor (LIF), and releasing tumor necrosis factor-stimulated gene-6 (TSG-6) to inhibit excessive microglial activation. However, in chronic neurodegenerative diseases, the phenotypic transformation of astrocytes contributes to microenvironmental deterioration. The secretion of chondroitin sulfate proteoglycans (CSPGs) inhibits OPC migration via the RhoA/ROCK pathway, while the persistent release of reactive oxygen species (ROS) leads to mitochondrial dysfunction and the upregulation of complement C3-mediated synaptic pruning. This article reviews the mechanisms by which astrocytes regulate the development and regeneration of myelin sheaths in the CNS, with a focus on analyzing the multifaceted roles of astrocytes in this process. It emphasizes that astrocytes serve as central hubs in maintaining myelin homeostasis by establishing a metabolic microenvironment and signaling network, aiming to provide new therapeutic strategies for neurodegenerative diseases such as multiple sclerosis.

Humans ; Aged ; Lung Diseases ; Pneumonia/drug therapy* ; Adrenal Cortex Hormones/therapeutic use* ; Pulmonary Disease, Chronic Obstructive/drug therapy* ; Administration, Inhalation ; Community-Acquired Infections/drug therapy*

Macroautophagy (referred to as autophagy hereafter) is a major intracellular lysosomal degradation pathway that is responsible for the degradation of misfolded/damaged proteins and organelles. Previous studies showed that autophagy protects against acetaminophen (APAP)-induced injury (AILI) via selective removal of damaged mitochondria and APAP protein adducts. The lysosome is a critical organelle sitting at the end stage of autophagy for autophagic degradation via fusion with autophagosomes. In the present study, we showed that transcription factor EB (TFEB), a master transcription factor for lysosomal biogenesis, was impaired by APAP resulting in decreased lysosomal biogenesis in mouse livers. Genetic loss-of and gain-of function of hepatic TFEB exacerbated or protected against AILI, respectively. Mechanistically, overexpression of TFEB increased clearance of APAP protein adducts and mitochondria biogenesis as well as SQSTM1/p62-dependent non-canonical nuclear factor erythroid 2-related factor 2 (NRF2) activation to protect against AILI. We also performed an unbiased cell-based imaging high-throughput chemical screening on TFEB and identified a group of TFEB agonists. Among these agonists, salinomycin, an anticoccidial and antibacterial agent, activated TFEB and protected against AILI in mice. In conclusion, genetic and pharmacological activating TFEB may be a promising approach for protecting against AILI.

Aim To analyze the anti-A549 and HI299 lung ade-nocarcinoma activities via using examples of baicalin, astragalo-side, hesperidin and cisplatin based on real time cellular analysis (RTCA) technology, and to build a new strategy for EC50 e-valuation reflecting the time-dimensional characteristic. Methods Using RTCA Software Pro for data analysis and GraphPad Prism and Origin Pro plotting, the in vitro anti-A549 and H1299 lung adenocarcinoma activities of baicalin, astragaloside, hesperidin, and cisplatin were characterized using the endpoint method and time dimension, respectively. Results (X) There were significant differences in EC50 values of A549 and H1299 cells at 24 h and 48 h endpoint methods. (2) The correlation coefficient of the curve fitted with the four-parameter equation was > 0. 9, and the dynamic change of EC50 remained relatively stable (the linear fitting of EC50 at adjacent 4 points I slope 1^1) used to calculate the EC50 value within this time dimension. The EC50 of baicalin, astragaloside, hesperidin and cisplatin on A549 cells was 52. 97 ±1.75 плпо! • L~1(16~48 h) , 62.88 ± 2.91 ijunol • L"1 (32.25 -48 h) , 78.84 ±0.33 плпо1 • L"1 (21.5 -29.75 h), 13.57 ±1.54 плпо1 • L_1(27.5 -48 h), respectively; the EC50 of baicalin, astragaloside, hesperidin and cisplatin on H1299 cells was 43. 71 ± 1. 26 |лто1 • L_1 ( 19. 5 -48 h), 47.23 ±1. 19 |лто1 • L_1(14 -48 h) , 39.45 ±0.24 плпо1 • L"1 (12.75 -46.25 h), 25.97 ±4.76 плпо1 • L"1 (10. 25 -48 h) , respectively. The results showed that the time window for the anti-tumor effect of the test solution/drug was different. Conclusions Based on RTCA technology, it is more accurate and reasonable to select EC50 data that exhibit better fitting, stable changes, and time-dimensional characteristics for the evaluation of anti-tumor activity. In addition, this method of distinguishing different effective time of antitumor drugs can provide a reference for the timing of clinical combination drugs, and this approach will also provide a reference for further related studies.

Objective To study the microscopic structure and morphological characteristics of Zebrafish eyeball and retina at different developmental stages, and to lay a foundation for visual research model. Methods Select eight groups of zebrafish at different ages, with six fish in each group, 48 fish in total. Optical microscopy and transmission electron microscopy were used to observe the eyeball structure of Zebrafish at different developmental stages, and the thickness of retinal each layer was measured to analyze the temporal and spatial development pattern. The morphological characteristics of various cells in the retina and the way of nerve connection were observed from the microscopic and ultrastructural aspects, especially the structural differences between rod cells and cone cells. Results The retina of Zebrafish can be divided into ten layers including retinal pigment epithelial layer, rod cells and cone cells layer, outer limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, nerve fiber layer, inner limiting membrane. Rod cells had a smaller nucleus and a higher electron density than cone cells. Photoreceptor terminals were neatly arranged in the outer plexiform layer, forming neural connections with horizontal cells and bipolar cells, and several synaptic ribbons are clearly visible within them. In Zebrafish retina, ganglion cell layer and inner plexiform layer are the earliest developed. With the growth and development of Zebrafish, the thickness of rod cells and cone cells layer and retinal pigment epithelial layer gradually increases, and the retinal structure was basically developed in about 10 weeks. Conclusion The retinal structure of Zebrafish is typical, with obvious stratification and highly differentiated nerve cells. There are abundant neural connections in the outer plexiform layer. The ocular development characteristics of Zebrafish are similar to those of most mammals.

In the past few decades, microbubbles were widely used as ultrasound contrast agents in the field of tumor imaging. With the development of research, ultrasound targeted microbubble destruction technology combined with drug-loaded microbubbles can achieve precise drug release and play a therapeutic role. As a micron-scale carrier, microbubbles are difficult to penetrate the endothelial cell space of tumors, and nano-scale drug delivery system—nanobubbles came into being. The structure of the two is similar, but the difference in size highlights the unique advantages of nanobubbles in drug delivery. Based on the classification principle of shell materials, this review summarized micro/nanobubbles used for ultrasound diagnosis or treatment and discussed the possible development directions, providing references for the subsequent development.

Objective To investigate the therapeutic effect of Huatan Jieyu Anshen Decoction(mainly with the actions of resolving phlegm,relieving depression and calming mind)combined with abdominal vibration tuina manipulations on chronic insomnia in the elderly.Methods Ninety-four cases of elderly patients with chronic insomnia of phlegm-heat harassing the interior type were randomly divided into the observation group and the control group,with 47 cases in each group.The control group was given Huatan Jieyu Anshen Decoction orally,while the observation group was given oral use of Huatan Jieyu Anshen Decoction combined with abdominal vibration tuina manipulations.The course of treatment for the two groups lasted for 4 weeks.Before and after the treatment,the two groups were observed in the changes of traditional Chinese medicine(TCM)syndrome scores,Pittsburgh Sleep Quality Index(PSQI)score,Athens Insomnia Scale(AIS)score,Fatigue Scale-14(FS-14)score,World Health Organization Quality-of-Life Brief Scale(WHOQOL-BREF)score,and the serum levels of melatonin(MT),dopamine(DA),and cortisol(CORT).After treatment,the clinical efficacy of the two groups was evaluated.Results(1)After 4 weeks of treatment,the total effective rate of the observation group was 97.88%(46/47),while that of the control group was 87.23%(41/47),and the intergroup comparison(tested by chi-square test)showed that the therapeutic efficacy of the observation group was superior to that of the control group(P＜0.01).(2)After treatment,the scores of primary and secondary TCM symptoms in the two groups were significantly decreased compared with those before treatment(P＜0.05),and the decrease of the scores of primary and secondary TCM symptoms in the observation group was significantly superior to that in the control group(P＜0.01).(3)After treatment,the PSQI scores,AIS scores,and FS-14 scores in the two groups were significantly decreased compared with those before treatment(P＜0.05),and the WHOQOL-BREF scores were significantly increased compared with those before treatment(P＜0.05).The decrease of the PSQI scores,AIS scores and FS-14 scores as well as the increase of the WHOQOL-BREF scores in the observation group was significantly superior to that in the control group(P＜0.01).(4)After treatment,the serum MT level of both groups was significantly higher than that before treatment(P＜0.05),and the serum DA and CORT levels were significantly lower than those before treatment(P＜0.05).The increase in serum MT level and the decrease in serum DA and CORT levels of the observation group were significantly superior to those of the control group(P＜0.01).Conclusion The combined therapy of Huatan Jieyu Anshen Decoction combined with vibration tuina manipulations can achieve satisfactory efficacy in the elderly patients with chronic insomnia of phlegm-heat harassing the interior syndrome.The therapy is effective on regulating the central nervous system of the patients,improving the quality of the sleep,and promoting the relief of fatigue and the enhancement of the quality of life,which has great significance to the enhancement of the overall therapeutic efficacy of insomnia.