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.

N-acetyl-p-aminophenol （APAP） is an antipyretic analgesic commonly used in clinical practice， and APAP overdose can cause severe liver injury and even death. In recent years， the incidence rate of APAP-induced liver injury （AILI） tends to increase， and it has become the second most common cause of liver transplantation worldwide. Autophagy is a highly conserved catabolic process that removes unwanted cytosolic proteins and organelles through lysosomal degradation to achieve the metabolic needs of cells themselves and the renewal of organelles. A large number of studies have shown that autophagy plays a key role in the pathophysiology of AILI， involving the mechanisms such as APAP protein conjugates， oxidative stress， JNK activation， mitochondrial dysfunction， inflammatory response and apoptosis. This article elaborates on the biological mechanism of autophagy in AILI， in order to provide a theoretical basis for the treatment of AILI and the development of autophagy regulators.

ObjectiveTo explore the mechanism by which Buyang Huanwutang regulates the glutathione peroxidase 4 （GPX4）-acyl-CoA synthetase long-chain family member 4 （ACSL4） axis to inhibit ferroptosis and promote neurological functional recovery after spinal cord injury （SCI）. MethodsNinety rats were randomly divided into five groups： sham operation group， model group， low-dose Buyang Huanwutang group （12.5 g·kg^-1）， high-dose Buyang Huanwutang group （25 g·kg^-1）， and Buyang Huanwutang + inhibitor group （25 g·kg^-1 + 5 g·kg^-1 RSL3）. The SCI model was established by using the allen method. Tissue was collected on the 7th and 28th days after operation. Motor function was assessed by using the Basso-Beattie-Bresnahan （BBB） scale. Hematoxylin-eosin （HE）， Nissl， and Luxol fast blue （LFB） staining were performed to observe spinal cord histopathology. Transmission electron microscopy was used to examine mitochondrial ultrastructure. Immunofluorescence staining was used to detect the number of NeuN-positive cells and the fluorescence intensity of myelin basic protein （MBP）， GPX4， and ACSL4. Real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） was used to analyze the mRNA expression of GPX4 and ACSL4. Enzyme linked immunosorbent assay （ELISA） was performed to measure the levels of reactive oxygen species （ROS）， malondialdehyde （MDA）， glutathione （GSH）， and superoxide dismutase （SOD）. Colorimetric assays were used to determine the iron content in spinal cord tissue. ResultsCompared to the sham operation group， the model group exhibited significantly reduced BBB scores （P<0.01）， severe pathological damage in spinal cord tissue， and marked mitochondrial ultrastructural disruption. In addition， the model group showed a decrease in the number of NeuN-positive cells （P<0.01）， reduced fluorescence intensity of MBP and GPX4 （P<0.01）， lower levels of GSH and SOD （P<0.01）， and downregulated mRNA expression of GPX4 （P<0.01）. Moreover， compared to the sham operation group， the model group had elevated levels of ROS， MDA， and tissue iron content （P<0.01）， along with increased fluorescence intensity and mRNA expression of ACSL4 （P<0.01）. Compared with the model group and Buyang Huanwutang + inhibitor group， the Buyang Huanwutang group showed significantly improved BBB scores （P<0.05， P<0.01） and exhibited less severe spinal cord tissue damage， reduced edema and inflammatory cell infiltration， increased neuronal survival， and more intact myelin structures. Additionally， mitochondrial ultrastructure was significantly improved in the Buyang Huanwutang group. Compared to the model group and Buyang Huanwutang + inhibitor group， the Buyang Huanwutang group significantly increased the number of NeuN-positive cells and the fluorescence intensity of MBP （P<0.05， P<0.01）. Furthermore， Buyang Huanwutang significantly increased the fluorescence intensity and mRNA expression of GPX4 （P<0.01） and decreased the fluorescence intensity and mRNA expression of ACSL4 （P<0.01） compared to the model group and Buyang Huanwutang + inhibitor group. Finally， the Buyang Huanwutang group significantly decreased ROS， MDA， and tissue iron content （P<0.01） and significantly increased GSH and SOD levels （P<0.01） compared to the model group and Buyang Huanwutang + inhibitor group. ConclusionBuyang Huanwutang inhibits ferroptosis through the GPX4/ACSL4 axis， reduces secondary neuronal and myelin injury and oxidative stress， and ultimately promotes the recovery of neurological function.

Objective To investigate the role and related mechanisms of exosomes derived from mesenchymal stem cells (MSCs) in radiation-induced lung injury (RILI). Methods Human umbilical cord-derived MSCs were isolated and cultured for the extraction and identification of exosomes. Eighteen male SD rats were randomly divided into Control group, RILI group and RILI + exosomes group (EXO group), with 6 rats in each group. Except for Control group, the other groups received a single X-ray dose of 30 Gy to the right lung. Immediately after irradiation, the EXO group was administered 2 × 10⁹ exosomes/kg via tail vein injection. Control group and RILI group were given the same volume of normal saline. Eight weeks post-irradiation, the rats were sacrificed, lung tissue and peripheral venous blood were collected. HE and Masson staining were employed to observe the pathological and fibrotic changes of lung tissue. The levels of serum inflammatory factors IL-6, IFN-γ, TNF-α, and IL-10 were detected by ELISA. RT-qPCR was used to assess the mRNA levels of IL-1β, IL-6, Cdh1, and Col1a1 in lung tissue. The expression levels of Vimentin and TGF-β1 in lung tissue were measured by immunohistochemical staining. The expression levels of AMPK, p-AMPK, and TGF-β1 in lung tissue were detected by Western blot. Results MSC-derived exosomes were successfully extracted and identified. Compared with RILI group, EXO group showed significantly reduced pathological changes of lung inflammation and collagen deposition. The levels of serum inflammatory factors IL-6, INF-γ, and TNF-α were significantly decreased (P < 0.05), and the level of anti-inflammatory factor IL-10 was significantly increased (P < 0.05). The mRNA levels of IL-1β, IL-6, and Col1a1 in lung tissue were significantly decreased (P < 0.05 or P < 0.01), and the mRNA level of Cdh1 was significantly increased (P < 0.05 or P < 0.01). The levels of Vimentin and TGF-β1 in lung tissue were significantly reduced, while p-AMPK level was significantly up-regulated (P < 0.05). Conclusion Exosomes derived from MSCs may alleviate RILI by inhibiting inflammatory responses and regulating epithelial-mesenchymal transition mediated by AMPK/TGF-β1 signaling pathway.

The alternative pathway (AP) of the complement system is a key contributor to the pathogenesis of several diseases including paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), C3 glomerular disease (C3G) and age-related macular degeneration (AMD). Complement factor B (CFB) is a trypsin-like serine protein that circulates in the human bloodstream in a latent form. As a key node of the alternative pathway, it is an important target for the treatment of diseases mediated by the complement system. With the successful launch of iptacopan, the CFB small molecule inhibitors has become a current research hotspot, a number of domestic and foreign pharmaceutical companies are actively developing CFB small molecule inhibitors. In this paper, the research progress of CFB small molecule inhibitors in recent years is systematically summarized, the representative compounds and their activities are introduced according to structural types and design ideas, so as to provide reference and ideas for the subsequent research on CFB small molecule inhibitors.

Tumors are the second leading cause of death worldwide. Exosomes are a type of extracellular vesicle secreted from multivesicular bodies, with particle sizes ranging from 40 to 160 nm. They regulate the tumor microenvironment, proliferation, and progression by transporting proteins, nucleic acids, and other biomolecules. Compared with other drug delivery systems, exosomes derived from different cells possess unique cellular tropism, enabling them to selectively target specific tissues and organs. This homing ability allows them to cross biological barriers that are otherwise difficult for conventional drug delivery systems to penetrate. Due to their biocompatibility and unique biological properties, exosomes can serve as drug delivery systems capable of loading various anti-tumor drugs. They can traverse biological barriers, evade immune responses, and specifically target tumor tissues, making them ideal carriers for anti-tumor therapeutics. This article systematically summarizes the methods for exosome isolation, including ultracentrifugation, ultrafiltration, size-exclusion chromatography (SEC), immunoaffinity capture, and microfluidics. However, these methods have certain limitations. A combination of multiple isolation techniques can improve isolation efficiency. For instance, combining ultrafiltration with SEC can achieve both high purity and high yield while reducing processing time. Exosome drug loading methods can be classified into post-loading and pre-loading approaches. Pre-loading is further categorized into active and passive loading. Active loading methods, including electroporation, sonication, extrusion, and freeze-thaw cycles, involve physical or chemical disruption of the exosome membrane to facilitate drug encapsulation. Passive loading relies on drug concentration gradients or hydrophobic interactions between drugs and exosomes for encapsulation. Pre-loading strategies also include genetic engineering and co-incubation methods. Additionally, we review approaches to enhance the targeting, retention, and permeability of exosomes. Genetic engineering and chemical modifications can improve their tumor-targeting capabilities. Magnetic fields can also be employed to promote the accumulation of exosomes at tumor sites. Retention time can be prolonged by inhibiting monocyte-mediated clearance or by combining exosomes with hydrogels. Engineered exosomes can also reshape the tumor microenvironment to enhance permeability. This review further discusses the current applications of exosomes in delivering various anti-tumor drugs. Specifically, exosomes can encapsulate chemotherapeutic agents such as paclitaxel to reduce side effects and increase drug concentration within tumor tissues. For instance, exosomes loaded with doxorubicin can mitigate cardiotoxicity and minimize adverse effects on healthy tissues. Furthermore, exosomes can encapsulate proteins to enhance protein stability and bioavailability or carry immunogenic cell death inducers for tumor vaccines. In addition to these applications, exosomes can deliver nucleic acids such as siRNA and miRNA to regulate gene expression, inhibit tumor proliferation, and suppress invasion. Beyond their therapeutic applications, exosomes also serve as tumor biomarkers for early cancer diagnosis. The detection of exosomal miRNA can improve the sensitivity and specificity of diagnosing prostate and pancreatic cancers. Despite their promising potential as drug delivery systems, challenges remain in the standardization and large-scale production of exosomes. This article explores the future development of engineered exosomes for targeted tumor therapy. Plant-derived exosomes hold potential due to their superior biocompatibility, lower toxicity, and abundant availability. Furthermore, the integration of exosomes with artificial intelligence may offer novel applications in diagnostics, therapeutics, and personalized medicine.

ObjectiveTo observe the effect of Yangxin Tongmai Formula （养心通脉方） by midnight-noon ebb-flow administration method for rat models of premature coronary heart disease （PCHD） with blood stasis syndrome， and to explore the possible mechanism of action from the perspective of DNA methylation differential gene expression. MethodsThere were 3 SD rats in each of the blank group， model group and Yangxin Tongmai Formula group， and the rats in the model group and Yangxin Tongmai Formula group were fed with high-fat chow plus vitamin D3 by gavage plus isoproterenol hydrochloride by subcutaneous injection to construct rat models of PCHD with blood stasis syndrome. After successful modelling， rats in Yangxin Tongmai Formula group were gavaged with 18 g/（kg‧d） of Yangxin Tongmai Formula， and rats in blank group and the model group were gavaged with 4 ml/（kg‧d） of 0.9% NaCl solution， and serum samples of rats in each group were collected for DNA methylation sequencing after 3 weeks to screen for the relevant DNA methylation differentiation genes. In addition， rats with successful modelling of PCHD with blood stasis were randomly divided into model group， Yangxin Tongmai Formula with midnight-noon ebb-flow administration method group ［18 g/（kg‧d） of Yangxin Tongmai Formula was gavaged twice in the heart channel period （12：00） and pericardium channel period （20：00）］， the Yangxin Tongmai Formula control group ［18 g/（kg‧d） of Yangxin Tongmai Formula was gavaged twice at 8：00 and 18：00］ and the Atorvastatin Calcium group ［atorvastatin calcium tablets solution 1.8 mg/（kg‧d） at the same intervention time as that in Yangxin Tongmai Formula control group］， and set up a blank group of 8 rats in each group. The model group and blank group were gavaged with 0.9% NaCl solution 4 ml/（kg‧d） for the same time as the Yangxin Tongmai Formula control group. After 3 weeks of gavage， the blood lipids ［including total cholesterol （TC）， low-density lipoprotein （LDL）， high-density lipoprotein （HDL）］ levels of rats in each group were detected； the HE staining of myocardial tissues and thoracic aorta was used to observe the pathomorphological changes； the levels of serum inflammation indexes ［tumour necrosis factor alpha （TNF-alpha）， lipopolysaccharide （LPS）， and interleukin 10 （IL-10）］ were detected； immunoprecipitation-realtime fluorescence quantitative PCR was used to detect the relative expression of cardiac tissue screening differential genes. ResultsThe genes screened for differentially methylated regions were calmodulin 2 （Calm2）， calcium voltage-gated channel subunit α1s （Cacna1s）， and phospholipase Cβ1 （Plcb1）. Compared with the blank group， rats in the model group showed elevated levels of TC， LDL， TNF-α and LPS， and decreased levels of HDL and IL-10 （P＜0.05 or P＜0.01）； HE staining showed obvious swelling of myocardial fibres， accompanied by a large number of inflammatory cell infiltration， and thickening of the inner wall of the aortic vessels with internal wall damage， which was visible as a large number of lipid cholesterol crystals and obvious inflammatory cell infiltration. Compared with the model group， the TC， LDL， TNF-α and LPS contents of rats in the Yangxin Tongmai Formula with midnight-noon ebb-flow administration method group， the Yangxin Tongmai Formula control group， and the atorvastatin calcium group all reduced， and the contents of HDL and IL-10 all elevated （P＜0.05）， with the improvement of myocardial tissue damage and the reduction of inflammatory infiltration， and the improvement of the damage of the inner lining of the thoracic aorta and the reduction of lipid infiltration. Compared with Yangxin Tongmai Formula control group， LDL， TNF-α and LPS contents reduced， and IL-10 contents increased in the midnight-noon ebb-flow administration method group （P＜0.05）. Compared with the model group， the relative expression of Calm2 and Plcb1 genes decreased and the relative expression of Cacna1s gene increased in Yangxin Tongmai Formula control group and the midnight-noon ebb-flow administration method group （P＜0.05）； compared with the Yangxin Tongmai Formula control group， the relative expression of Calm2 gene decreased and the relative expression of Cacna1s gene increased in the midnight-noon ebb-flow administration method group （P＜0.05）. ConclusionThe intervention of Yangxin Tongmai Formula in the heart channel period （12：00） and pericardium channel period （20：00） was more effective in improving the blood lipid level， inhibiting inflammation， and improving myocardial tissue damage in rats of PCHD with blood stasis syndrome， and Calm2 and Cacna1s genes may be the key targets of Yangxin Tongmai Formula in intervening the blood stasis syndrome of PCHD.

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.

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*

ObjectiveTo investigate the clinical efficacy of Huangqi injection combined with Buzhong Yiqi acupuncture in the treatment of chronic fatigue syndrome （CFS） with Qi deficiency and its effects on TCM syndromes， fatigue symptoms， serum superoxide dismutase （SOD）， malondialdehyde （MDA）， and oxidized low-density lipoprotein （ox-LDL） levels. MethodA total of 200 patients with CFS of Qi deficiency were randomly divided into a control group （100 cases） and an observation group （100 cases）. The control group was treated with vitamin B compounds， and the observation group was treated with Huangqi injection combined with Buzhong Yiqi acupuncture for two weeks. The scores of TCM syndromes， fatigue symptoms， levels of serum SOD， MDA， and ox-LDL and the incidence of adverse reactions were observed and compared before and after treatment in two groups. ResultAfter treatment， the total effective rate of the control group was 54.34% （50/92）， while that of the observation group was 88.54% （85/96）. The total effective rate of the observation group was higher than that of the control group （χ²=27.13，P<0.05）. Compared with those in the two groups before treatment， scores of fatigue self-assessment scale （FSAS）， physical fatigue and mental fatigue， and sleep/rest response scores of fatigue in the two groups after treatment were significantly decreased （P<0.05）. After treatment， scores of FSAS， physical fatigue and mental fatigue， and sleep/rest response scores of fatigue in the observation group were significantly decreased compared with those in the control group （P<0.05）. Compared with those in the two groups before treatment， TCM syndrome scores in the two groups after treatment were significantly decreased （P<0.05）. After treatment， TCM syndrome scores in the observation group were significantly decreased compared with those in the control group （P<0.05）. Compared with those in the two groups before treatment， MDA levels in the two groups were significantly decreased （P<0.05）， ox-LDL levels in the observation group were significantly decreased （P<0.05）， and SOD levels were significantly increased （P<0.05）. After treatment， compared with those in the control group， the serum MDA and ox-LDL levels in the observation group were significantly decreased （P<0.05）， and the serum SOD was significantly increased （P<0.05）. No serious adverse events or adverse reactions occurred during this clinical trial. ConclusionHuangqi injection combined with Buzhong Yiqi acupuncture has a good clinical curative effect in the treatment of CFS with Qi deficiency， which can effectively improve the fatigue symptoms of patients， increase the level of SOD， and reduce the level of serum MDA and ox-LDL. It is related to the production of antioxidants， inhibiting the production of lipid peroxides， and improving the body's ability to resist oxidative stress.