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.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

To study the ameliorative effect of Eucommiae Cortex extract on spatial learning disabilities in APP/PS1 double-transgenic mice and explore its relationship with estrogen receptor β(ERβ)/c-Jun N-terminal kinase(JNK) signaling pathway, sixty 3-month-old male APP/PS1 mice were randomly divided into a model group, an anti-brain failure capsule group(0.585 g·kg~(-1)), a donepezil hydrochloride group(0.65 mg·kg~(-1)), and a Eucommiae Cortex extract group(1.3 g·kg~(-1)), and 15 C57BL/6 mice of the same genetic background were set as WT control group. The learning and memory ability of mice was assessed by the Morris water maze test(MWM), the passive avoidance test(PAT), and the novel object recognition test(NOR). The histomorphological and cellular ultrastructural features of the hippocampal region of the mice were observed by hematoxylin-eosin(HE) staining and transmission electron microscopy(TEM); the molecular docking validation of the key active ingredients and the key targets was performed by using AutoDock Vina software, and the immunohistochemical method(IHC) was used to detect the ERβ expression in the dentate gyrus(DG) area of mouse hippocampus. Western blot(WB) was utilized to detect the expression of ERβ, p-JNK, and JNK in mouse hippocampal area. Compared with those in the WT control group, the results of behavioral experiments showed that the latency of the mice in the model group was significantly increased, the number of platform traversals, and the target quadrant residence time were significantly decreased in the MWM. The evasion latency was significantly reduced, and the number of errors was significantly increased in the PAT. The index of recognition of novel objects was significantly reduced in the NOR. The results of HE staining indicated that the hippocampal area of mice in the model group showed a decrease in the number of neurons, disorganization of pyramidal cell arrangement, nucleus consolidation, and other changes. TEM results showed that some neuronal nuclei in the hippocampal area had a consolidated state, slightly thickened and aberrant nuclear membranes, and fewer intracytoplasmic nidus bodies; the IHC results showed that the expression of ERβ in the hippocampal DG area of the mice was reduced. The WB results showed that the ERβ expression in the hippocampal tissue was decreased, and the p-JNK/JNK level was elevated. Compared with the model group, the Eucommiae Cortex extract group showed a significant decrease in latency, and increase in number of platform traversals and target quadrant residence time in the MWM, a significant increase in evasion latency and decrease in number of errors in the PAT, and a significant increase in the index of recognition of novel objects in the NOR. In addition, there was an increase in the number of neurons in the hippocampal area of mice. The pyramidal cells tended to be arranged in an orderly manner; the nuclei of neurons in the hippocampal area were in a better state; the expression of ERβ in the hippocampal DG area of the mice was elevated; the expression of ERβ in the hippocampal tissue was elevated, and the level of p-JNK/JNK was reduced. The effects of donepezil hydrochloride group and anti-brain failure capsule on APP/PS1 mice in terms of behavioral, HE, and TEM indexes were similar to those of Eucommiae Cortex extract, and there was no significant difference between donepezil hydrochloride group and the model group in IHC and WB experiments, and the results of molecular docking indicated that the estrogen-like components in Eucommiae Cortex extract were tightly bound to ERβ. In conclusion, the binding of Eucommiae Cortex extract to estrogen receptors, regulation of ERβ expression, and activation of ERβ/JNK signaling pathway may be one of the key mechanisms by which it improves the learning and memory ability of APP/PS1 mice.
Animals ; Male ; Mice ; Mice, Transgenic ; Memory/drug effects* ; Mice, Inbred C57BL ; Estrogen Receptor beta/genetics* ; Eucommiaceae/chemistry* ; Alzheimer Disease/psychology* ; Amyloid beta-Protein Precursor/metabolism* ; Presenilin-1/metabolism* ; Humans ; MAP Kinase Signaling System/drug effects* ; Drugs, Chinese Herbal/administration & dosage* ; Hippocampus/metabolism* ; Maze Learning/drug effects* ; Learning/drug effects*

Asarum forbesii is a perennial herb born in a shaded and humid environment, which is warm in nature. With the efficacy of warming lung, resolving fluid retention, and relieving coughs, it can be used to treat the syndrome of cold fluid accumulating in lung. To investigate the effects of different shading conditions on the composition and efficacy of A. forbesii, this study planted A. forbesii under 20% natural light(NL20), 40% natural light(NL40), 60% natural light(NL60), and 80% natural light(NL80) and utilized ultra performance liquid chromatography(UPLC) and micro broth 2-fold dilution method to detect the volatile chemical compounds and the minimum inhibitory concentration. At the same time, the study investigated the effects of A. forbesii grown under different shading conditions on the signs, pathological changes of lung tissues, serum cytokine levels, activities of mitochondrial respiratory chain complexes Ⅰ-Ⅴ in lung tissues, and relative expression of related genes of mice with syndrome of cold fluid accumulating in lung. The results indicated that with the increase of shading, the content of kakuol, methyl eugenol, and asarinin in A. forbesii and the antibacterial effect showed a tendency of increasing first and then decreasing, and the NL40 group was significantly better than the other groups. Under the conditions of NL20 and NL40, A. forbesii significantly alleviated the pathological damage to lung tissues, restored the homeostasis of the lung, and enhanced the energy metabolism level of mice with syndrome of cold fluid accumulating in lung. In addition, A. forbesii planted under the two conditions reduced the content of interleukin-8(IL-8), interleukin-13(IL-13), tumor necrosis factor-α(TNF-α), and mucin 5AC(MUC5AC), increased the levels of interleukin-10(IL-10) and aquaporin 1(AQP1), lowered the expression of MMP9, VEGF, TGF-β, and MAPK3. In conclusion, the therapeutic effect of A. forbesii on the syndrome of cold fluid accumulating in lung was positively correlated with the degree of shading, and the chemical composition and efficacy of warming lung and resolving fluid retention were optimal under the conditions of NL20-NL40. This study can provide reference for the pharmacological research and cultivation of A. forbesii.
Animals ; Mice ; Lung/pathology* ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Light ; Cytokines/genetics* ; Humans

This study aimed to compare the ameliorative effects of Lycii Fructus and Chrysanthemi Flos at different ratios on retinal damage in mice and to elucidate the underlying mechanisms. A retinal injury model was established by intraperitoneal injection of sodium iodate(NaIO_3) solution. The mice were divided into the following groups: blank group, model group, positive drug(AREDS 2) group, low-and high-dose groups of Lycii Fructus and Chrysanthemi Flos at 1∶1, low-and high-dose groups at 3∶1, and low-and high-dose groups at 1∶3. Administration was carried out 15 days after modeling. The visual acuity of the mice was assessed using the black-and-white box test. The fundus was observed using an optical coherence tomography device, and retinal thickness was measured. HE staining was used to observe the morphology and pathological changes of the retina. The levels of oxidative factors in serum and ocular tissues were measured using assay kits. The levels of inflammatory factors in serum and ocular tissues were detected by enzyme-linked immunosorbent assay(ELISA), and the expression of Nrf2, HO-1, and NF-κB proteins in ocular tissues was analyzed by Western blot. The results showed that after administration of Lycii Fructus and Chrysanthemi Flos at different ratios, the model group showed improved retinal thinning and disordered arrangement of retinal layers, elevated content of SOD and GSH in the serum and ocular tissues, and reduced levels of MDA, TNF-α, IL-1β, and IL-6. Lycii Fructus and Chrysanthemi Flos at 1∶1 and 1∶3 showed better improvement effects. The combination significantly upregulated the expression levels of Nrf2 and HO-1 and downregulated the expression of NF-κB p65. These results indicate that Lycii Fructus and Chrysanthemi Flos at different ratios can improve retinal damage, reduce oxidative stress, and alleviate inflammation in both the body and ocular tissues of mice. The mechanism may be related to the regulation of the Nrf2/HO-1 and NF-κB signaling pathways in ocular tissues. These findings provide a theoretical basis for the clinical application of Lycii Fructus and Chrysanthemi Flos in the treatment of dry age-related macular degeneration.
Animals ; Mice ; Retina/injuries* ; Male ; Lycium/chemistry* ; Drugs, Chinese Herbal/administration & dosage* ; Chrysanthemum/chemistry* ; NF-kappa B/genetics* ; Humans ; Retinal Diseases/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress/drug effects* ; Flowers/chemistry* ; Heme Oxygenase-1/genetics*

In order to compare the differences in growth and secondary metabolite accumulation of Panax quinquefolius between understory and field planting, growth indexes, photosynthetic characteristics, soil enzyme activities, secondary metabolite contents, and antioxidant activities of P. quinquefolius under different planting modes were examined and compared, and One-way analysis of variance(ANOVA) and correlation analyses were carried out by using the software SPSS 25.0 and GraphPad Prism 9.5. The Origin 2021 software was used for plotting. The results showed that compared with those under field planting, the plant height, leaf length, leaf width, photosynthetic rate, and chlorophyll content of P. quinquefolius under understory planting were significantly reduced, and arbuscular mycorrhizal fungi(AMF) infestation rate and infestation intensity, ginsenoside content, and antioxidant activity were significantly increased. The activities of inter-root soil urease, sucrase, and catalase increased, while the activities of non-inter-root soil urease and alkaline phosphatase increased. Correlation analyses showed that the plant height and leaf length of P. quinquefolius plant were significantly positively correlated with net photosynthetic rate, transpiration rate, chlorophyll content, and electron transfer rate(P<0.05), while ginsenoside content was significantly negatively correlated with net photosynthetic rate, chlorophyll content, and electron transfer rate(P<0.05) and significantly positively correlated with AMF infestation rate and infestation intensity(P<0.05). In addition, ginsenoside content was significantly positively correlated with the activities of inter-root soil sucrase, urease, and catalase(P<0.05). This study provides basic data for revealing the mechanism of secondary metabolite accumulation in P. quinquefolius under understory planting and for exploring and practicing the ecological mode of P. quinquefolius under understory planting.
Panax/microbiology* ; China ; Secondary Metabolism ; Soil/chemistry* ; Photosynthesis ; Plant Leaves/metabolism* ; Chlorophyll/metabolism* ; Mycorrhizae

Based on copper death, this study investigates the effect and mechanism of Shenmai Injection on isoproterenol(ISO)-induced myocardial fibrosis(MF) in rats. SPF-grade male SD rats were randomly divided into a normal group, model group, captopril(5 mg·kg~(-1)) positive control group, and Shenmai Injection low(6 mL·kg~(-1)), medium(9 mL·kg~(-1)), and high(12 mL·kg~(-1)) dose groups. Except for the normal group, the rats in the other groups were subcutaneously injected with ISO(5 mg·kg~(-1)) once a day for 10 consecutive days to establish an MF model. Starting from the second day after successful modeling, intraperitoneal injections of the respective treatments were administered for 28 consecutive days. Hematoxylin-eosin(HE) and Masson staining were used to observe pathological changes and fibrosis levels in the myocardial tissue. Colorimetry was employed to detect serum Cu~(2+) concentration in rats. The levels of inflammatory cytokines interleukin-6(IL-6), interleukin-1β(IL-1β), interleukin-18(IL-18), tumor necrosis factor-α(TNF-α), as well as mitochondrial energy metabolites adenosine triphosphate(ATP), adenosine diphosphate(ADP), and adenosine monophosphate(AMP) in serum were measured using enzyme-linked immunosorbent assay(ELISA). Western blot was performed to detect the expression of collagen Ⅰ(Col-Ⅰ), collagen Ⅲ(Col-Ⅲ), and copper death-related proteins dihydrolipoamide acetyltransferase(DLAT), ferredoxin 1(FDX1), lipoic acid synthetase(LIAS), and heat shock protein 70(HSP70) in myocardial tissue. Immunofluorescence was used to detect the expression of DLAT, FDX1, and HSP70, while immunohistochemistry was conducted to examine the expressions of DLAT, FDX1, LIAS, and HSP70. The results showed that, compared to the model group, the myocardial structure disorder and collagen fiber deposition in the drug treatment groups were significantly improved, the cardiac index level was reduced, serum Cu~(2+), IL-6, IL-1β, IL-18, TNF-α, ADP, and AMP levels were significantly decreased, ATP levels were significantly increased, and the expressions of Col-Ⅰ, Col-Ⅲ, and HSP70 proteins in myocardial tissue were significantly reduced, while the expressions of DLAT, FDX1, and LIAS proteins were significantly elevated. In conclusion, Shenmai Injection effectively alleviates myocardial structure disorder and interstitial collagen fiber deposition in ISO-induced MF rats, promotes copper excretion, and reduces copper death in the ISO-induced rat MF model.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Myocardium/metabolism* ; Drug Combinations ; Fibrosis/metabolism* ; Copper/blood* ; Cardiomyopathies/genetics* ; Humans

ObjectiveTo characterize the seasonal patterns of influenza in Kunming City, Yunnan Province before, during, and after the COVID-19 pandemic, and provide scientific evidence for optimizing influenza prevention and control strategies. MethodsInfluenza-like illness (ILI) and etiological surveillance data for influenza from the 14^th week of 2010 to the 13^th week of 2024 in Kunming City of Yunnan Province were collected. Harmonic regression models were constructed to analyze the epidemic characteristics and seasonal patterns of influenza before (2010/2011‒2019/2020 influenza seasons), during (2020/2021‒2022/2023 influenza seasons), and after (2023/2024 influenza season) the COVID-19 pandemic. ResultsBefore the COVID-19 pandemic, influenza in Kunming City mainly exhibited an annual cyclic pattern without a significant semi-annual periodicity, peaking from December to February of the next year, with an epidemic duration of 20‒30 weeks. During the pandemic, influenza seasonality shifted, with an increase in semi-annual periodicity and an approximate one month delay in annual peaks. However, after the pandemic, the annual amplitude of influenza increased compared with that before the pandemic, and the epidemic duration extended by about one month. Although the annual peak largely reverted to the pre-pandemic levels, the annual peaks for different influenza subtypes/lineages had not fully recovered. ConclusionInfluenza seasonality in Kunming City underwent substantial alterations following the COVID-19 pandemic and has not yet fully reverted to pre-pandemic levels. Continuous surveillance on different subtypes/lineages of influenza viruses remains essential, and prevention and control strategies should be adjusted and optimized in a timely manner based on current epidemic trends.

Objective To investigate the effect of up-regulating tumor necrosis factor alpha induced protein 3(TNFAIP3)expression on hippocampal neurons in mice with cerebral ischemia-reperfusion.Methods The mice were randomly divided into 6 groups:sham group,sham empty vector group(sham-),sham TNFAIP3 high expression group(sham+),model group,model empty vector group(model-),model TNFAIP3 high expression group(model+).A mouse model of middle cerebral artery occlusion and cerebral ischemia-reperfusion was established using the suture method.After the successful establishment of the model,lentivirus was injected into the hippocampus 24 hours later.Two weeks later,samples were collected and Western blotting was used to detect the expressions of TNFAIP3 and ERK signaling pathway proteins.The changes in ischemic area were observed by 2,3,5-triphenyltetrazolium chloride(TTC)staining;HE staining was used to observe the morphological changes of hippocampal neurons,and ELISA was used to detect the expressions of lipoprotein-associated phospholipase A2(Lp-PLA2)and interleukin(IL)-8.Results The results of Western blotting indicated that the TNFAIP3 expression in the model group decreased significantly compared with the sham group(P＜0.05);Compared with the model group,there was no significant change in TNFAIP3 expression in the model-group(P＞0.05);The TNFAIP3 expression in the model+group increased significantly compared with the model group and model-group(P＜0.05).Compared with the sham group,the results of the sham+group showed that the ischemic area had no significant changes in TTC staining,and there were no significant changes in hippocampal neuronal morphology,and the expressions ERK signaling pathway proteins,Lp-PLA2 and IL-8(P＞0.05);Compared with the sham-and sham+groups,the model group showed an increase in ischemic area,significant damage to hippocampal neurons,a decrease in the number of Nissl bodies,and a significant increase in the expressions of ERK signaling pathway proteins,Lp-PLA2,and IL-8(P＜0.05);Compared to the model-group,the model+group showed a decrease in ischemic area,an increase in the number of neurons in the hippocampus and the number of Nissl bodies,and a significant decrease in the expressions of ERK signaling pathway proteins,Lp-PLA2,and IL-8(P＜0.05).Conclusion Up-regulation of TNFAIP3 may be one of the methods for repairing hippocampal neuronal damage caused by cerebral ischemia reperfusion.

Objective To investigate the effects of remimazolam(REM)on cerebral ischemia-reperfusion injury(CIRI)rats and the AMP-activated protein kinase(AMPK)/NOD-like receptor protein 3(NLRP3)signaling pathway.Methods One hundred rats were selected to construct the CIRI rat model(Mod)and stochastically separated into a Mod group,low,medium,and high dose remifentanil groups(REM-L,REM-M,REM-H),and high dose remifentanil+pathway inhibitor Compound C group(REM-H+Compound C),with 20 rats in each group.Another 20 healthy rats were included as the control(Ctrl)group.All rats were subjected to neurobehavioral scoring.The water content,infarct area,and oxidative stress indicators of brain tissue were detected.The morphology and apoptosis of brain tissue were observed by HE and TUNEL staining.Western blotting was applied to detect protein expression related to the AMPK/NLRP3 signaling pathway.Results Compared with the Mod group,with the increase of REM dose,the movement disorders in rats were alleviated,the overall structure of brain tissue gradually recovered,pathological damage was reduced,the area of cerebral infarction,brain water content,and apoptosis rate of brain tissue cells decreased,reactive oxygen species(ROS)level,malondialdehyde(MDA)content,and NLRP3 and Caspase-1 protein expression levels decreased,superoxide dismutase the(SOD)content and AMPK protein expression level increased(P＜0.05).Compared with the REM-H group,the REM-H+Compound C group showed aggravated motor disorders,and more severe pathological damage to brain tissue,the area of cerebral infarction,cerebral water content and apoptosis rate of brain tissue cells increased,the ROS level,MDA content and the protein expression of NLRP3 and Caspase-1 increased,while the content of SOD and the protein expression decreased(P＜0.05).Conclusion Remimazolam can enhance the antioxidant function of the body,reduce brain cell apoptosis,alleviate brain tissue injury,and thus have a certain protective effect on ischemia-reperfusion brain injury in rats,the mechanism of which may be related to the activation of the AMPK/NLRP3 signaling pathway.