1.Strategies and Challenges of Hydrogen Production Catalyzed by Bioencapsulated Hydrogenase
Progress in Biochemistry and Biophysics 2026;53(5):1415-1438
Hydrogenases, as a class of highly efficient and reversible biological catalysts, can catalyze the reduction of protons to molecular hydrogen, thus demonstrating great potential in a wide range of fields such as renewable energy production and green chemistry. Despite their significant potential, the large-scale industrial application of hydrogenases has long been constrained by several inherent limitations, including high sensitivity to molecular oxygen, the challenges in the in vitro reconstitution and maturation of their catalytic centers, and the inefficiency and instability of the natural electron transfer pathways. To overcome these limitations and enhance the catalytic performance of hydrogenases, researchers have developed various strategies, among which enzyme molecular engineering, photo-driven modification, and enzyme immobilization techniques are the most common exploration directions. Particularly, enzyme immobilization technology is widely used to improve the reusability of hydrogenases, but traditional immobilization methods often come with disadvantages in practical applications, such as complex multi-step procedures and insufficient biocompatibility of the immobilization materials. In recent years, bioencapsulation technology has emerged as a promising alternative strategy to enhance the catalytic performance of hydrogenases. This method utilizes biologically derived encapsulation materials to construct physically confined and precisely defined chemical microenvironments around the enzyme molecules, offering simpler self-assembly processes and superior biocompatibility. With these biomimetic constructs, bioencapsulation technology not only provides better oxygen tolerance but also helps to create a local microenvironment conducive to sustained catalytic function. This article systematically reviews the latest research progress of two main bioencapsulation strategies for hydrogenases: one is the encapsulation technology based on protein-based nanocages; the other is the engineering strategy for whole-cell hydrogenase expression. In the nanocage-based systems, this article focuses on the structural and functional characteristics of virus-like capsids and carboxysome protein shells, which serve as efficient enzyme encapsulation scaffolds, not only providing a stable physical barrier to prevent oxygen diffusion but also enabling high-density enzyme loading, thereby promoting substrate channeling effects and electron transfer kinetics. This article also discusses whole-cell encapsulation systems, which achieve hydrogenase compartmentalization within engineered cellular structures or by using external natural polysaccharide-based encapsulation matrices to wrap whole-cell catalysts. Bioencapsulation strategies can bring multiple synergistic benefits: they can effectively protect hydrogenases from oxygen-mediated inactivation, significantly delay the decline of catalytic activity over time, and enhance the hydrogen production rate by increasing the local concentration of active enzyme molecules and optimizing the electron transfer efficiency from redox partners to the catalytic center.Despite the significant progress made, several technical challenges remain to be addressed. The main obstacles include limited enzyme loading and encapsulation efficiency, insufficient long-term stability of encapsulation materials under operating conditions, and the need to improve the matching of the photo-biological interface in systems integrating light-harvesting components with enzymatic catalysis. Future efforts can focus on the integration of multiple technological approaches, such as using computer-aided protein design to optimize encapsulation structures, developing engineered electron transfer pathways to enhance catalytic conversion efficiency, and designing composite multifunctional materials with both structural stability and functional adaptability. These directions collectively aim to achieve efficient, stable, and scalable hydrogen production applications of bioencapsulated hydrogenase systems.
2.Strategies and Challenges of Hydrogen Production Catalyzed by Bioencapsulated Hydrogenase
Progress in Biochemistry and Biophysics 2026;53(5):1415-1438
Hydrogenases, as a class of highly efficient and reversible biological catalysts, can catalyze the reduction of protons to molecular hydrogen, thus demonstrating great potential in a wide range of fields such as renewable energy production and green chemistry. Despite their significant potential, the large-scale industrial application of hydrogenases has long been constrained by several inherent limitations, including high sensitivity to molecular oxygen, the challenges in the in vitro reconstitution and maturation of their catalytic centers, and the inefficiency and instability of the natural electron transfer pathways. To overcome these limitations and enhance the catalytic performance of hydrogenases, researchers have developed various strategies, among which enzyme molecular engineering, photo-driven modification, and enzyme immobilization techniques are the most common exploration directions. Particularly, enzyme immobilization technology is widely used to improve the reusability of hydrogenases, but traditional immobilization methods often come with disadvantages in practical applications, such as complex multi-step procedures and insufficient biocompatibility of the immobilization materials. In recent years, bioencapsulation technology has emerged as a promising alternative strategy to enhance the catalytic performance of hydrogenases. This method utilizes biologically derived encapsulation materials to construct physically confined and precisely defined chemical microenvironments around the enzyme molecules, offering simpler self-assembly processes and superior biocompatibility. With these biomimetic constructs, bioencapsulation technology not only provides better oxygen tolerance but also helps to create a local microenvironment conducive to sustained catalytic function. This article systematically reviews the latest research progress of two main bioencapsulation strategies for hydrogenases: one is the encapsulation technology based on protein-based nanocages; the other is the engineering strategy for whole-cell hydrogenase expression. In the nanocage-based systems, this article focuses on the structural and functional characteristics of virus-like capsids and carboxysome protein shells, which serve as efficient enzyme encapsulation scaffolds, not only providing a stable physical barrier to prevent oxygen diffusion but also enabling high-density enzyme loading, thereby promoting substrate channeling effects and electron transfer kinetics. This article also discusses whole-cell encapsulation systems, which achieve hydrogenase compartmentalization within engineered cellular structures or by using external natural polysaccharide-based encapsulation matrices to wrap whole-cell catalysts. Bioencapsulation strategies can bring multiple synergistic benefits: they can effectively protect hydrogenases from oxygen-mediated inactivation, significantly delay the decline of catalytic activity over time, and enhance the hydrogen production rate by increasing the local concentration of active enzyme molecules and optimizing the electron transfer efficiency from redox partners to the catalytic center.Despite the significant progress made, several technical challenges remain to be addressed. The main obstacles include limited enzyme loading and encapsulation efficiency, insufficient long-term stability of encapsulation materials under operating conditions, and the need to improve the matching of the photo-biological interface in systems integrating light-harvesting components with enzymatic catalysis. Future efforts can focus on the integration of multiple technological approaches, such as using computer-aided protein design to optimize encapsulation structures, developing engineered electron transfer pathways to enhance catalytic conversion efficiency, and designing composite multifunctional materials with both structural stability and functional adaptability. These directions collectively aim to achieve efficient, stable, and scalable hydrogen production applications of bioencapsulated hydrogenase systems.
3.Bacteroi des fragilis-derived succinic acid promotes the degradation of uric acid by inhibiting hepatic AMPD2: Insight into how plant-based berberine ameliorates hyperuricemia.
Libin PAN ; Ru FENG ; Jiachun HU ; Hang YU ; Qian TONG ; Xinyu YANG ; Jianye SONG ; Hui XU ; Mengliang YE ; Zhengwei ZHANG ; Jie FU ; Haojian ZHANG ; Jinyue LU ; Zhao ZHAI ; Jingyue WANG ; Yi ZHAO ; Hengtong ZUO ; Xiang HUI ; Jiandong JIANG ; Yan WANG
Acta Pharmaceutica Sinica B 2025;15(10):5244-5260
In recent decades, the prevalence of hyperuricemia and gout has increased dramatically due to lifestyle changes. The drugs currently recommended for hyperuricemia are associated with adverse reactions that limit their clinical use. In this study, we report that berberine (BBR) is an effective drug candidate for the treatment of hyperuricemia, with its mechanism potentially involving the modulation of gut microbiota and its metabolite, succinic acid. BBR has demonstrated good therapeutic effects in both acute and chronic animal models of hyperuricemia. In a clinical trial, oral administration of BBR for 6 months reduced blood uric acid levels in 22 participants by modulating the gut microbiota, which led to an increase in the abundance of Bacteroides and a decrease in Clostridium sensu stricto_1. Furthermore, Bacteroides fragilis was transplanted into ICR mice, and the results showed that Bacteroides fragilis exerted a therapeutic effect on uric acid similar to that of BBR. Notably, succinic acid, a metabolite of Bacteroides, significantly reduced uric acid levels. Subsequent cell and animal experiments revealed that the intestinal metabolite, succinic acid, regulated the upstream uric acid synthesis pathway in the liver by inhibiting adenosine monophosphate deaminase 2 (AMPD2), an enzyme responsible for converting adenosine monophosphate (AMP) to inosine monophosphate (IMP). This inhibition resulted in a decrease in IMP levels and an increase in phosphate levels. The reduction in IMP led to a decreased downstream production of hypoxanthine, xanthine, and uric acid. BBR also demonstrated excellent renoprotective effects, improving nephropathy associated with hyperuricemia. In summary, BBR has the potential to be an effective treatment for hyperuricemia through the gut-liver axis.
4.Comparative Analysis of Exercise-induced Transcriptomic Responses in Human and Mouse Homologous Genes: Divergence and Convergence Based on The GEPREP Database
Qian SUN ; Wei-Chu TAO ; Ru WANG ; Bing-Xiang XU
Progress in Biochemistry and Biophysics 2025;52(6):1617-1630
Exercise, as a non-pharmacological intervention, holds a pivotal role in metabolic regulation, neuroplasticity, and immune homeostasis maintenance. However, human exercise studies are constrained by ethical limitations in tissue sampling, especially for key organs such as muscles and the brain. Meanwhile, rodent models like mice exhibit physiological differences in exercise patterns and metabolic rates from human. Despite these challenges, approximately 70% of human and mouse genes are conserved, providing a molecular basis for cross-species comparisons. This paper leverages the GEPREP database, which integrates human and mouse exercise transcriptomic data from multiple platforms, to conduct a comprehensive cross-species analysis of exercise-induced gene expression patterns. We employ a stringent data standardization process, including the conversion of orthologous genes and the filtering of low-expressing genes, to ensure the accuracy and reliability of the analysis. A mixed-effects model is utilized to assess differential gene expression across multiple cohorts, identifying genes that are significantly upregulated or downregulated in response to exercise. The analysis reveals a complex pattern of gene expression, with a significant number of genes showing conserved responses between humans and mice, particularly in acute aerobic exercise, where genes such as ATF3, PPARGC1A, and ANKRD1 are commonly upregulated. These genes are implicated in muscle stress response, metabolic regulation, and muscle adaptation, highlighting the shared molecular pathways activated by exercise across species. However, the study also uncovers substantial species-specific differences in gene expression, especially in chronic aerobic exercise, where the number of divergently regulated genes increases. These differences suggest that while some fundamental biological processes are conserved, the specific regulatory mechanisms and gene expression patterns can vary significantly between humans and mice. Functional enrichment analysis further reveals that conserved genes are involved in muscle development, inflammation regulation, and energy metabolism, while species-specific genes are associated with ion transport, extracellular matrix (ECM) organization, and muscle contraction, indicating the multifaceted impact of exercise on skeletal muscle function. The findings emphasize the importance of considering species-specific differences when interpreting results from animal models and translating them to human health applications. The study highlights the need for a more nuanced understanding of the molecular underpinnings of exercise-induced adaptations and underscores the value of cross-species comparative analyses in uncovering the evolutionary and functional basis of these responses. Future research should focus on integrating multi-omics data and expanding the analysis to include other tissues to provide a more comprehensive view of the systemic effects of exercise. Additionally, the development of species-specific gene editing models and the validation of key genes in exercise physiology will further enhance our understanding of the evolutionary logic behind exercise interventions. This study not only provides valuable insights into the molecular mechanisms of exercise-induced adaptations but also underscores the necessity of validating findings from animal models in human cohorts to ensure the reliability and applicability of translational research in exercise science. By addressing these aspects, the study aims to bridge the gap between basic research and clinical applications, ultimately contributing to the development of personalized exercise prescriptions and interventions that can effectively promote health and prevent diseases.
5.Expression and Clinical Significance of lncRNA NCK1-AS1 in Acute Myeloid Leukemia.
Chen CHENG ; Zi-Jun XU ; Pei-Hui XIA ; Xiang-Mei WEN ; Ji-Chun MA ; Yu GU ; Di YU ; Jun QIAN ; Jiang LIN
Journal of Experimental Hematology 2025;33(2):352-358
OBJECTIVE:
To detect and analyze the expression and clinical significance of long non-coding RNA tyrosine kinase non-catalytic region adaptor protein 1-antisense RNA1 (NCK1-AS1) in patients with acute myeloid leukemia (AML).
METHODS:
89 AML patients and 23 healthy controls were included from the People's Hospital Affiliated to Jiangsu University. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of NCK1-AS1 and NCK1 in bone marrow samples. The relationship between the expression of NCK1-AS1 and the clinical characteristics of patients were analyzed, as well as the correlation between NCK1-AS1 and NCK1.
RESULTS:
The expression level of NCK1-AS1 in all AML, non-M3 AML and cytogenetically normal AML (CN-AML) patients was significantly higher than that in the control group (P < 0.01, P < 0.05, P < 0.01, respectively). In non-M3 AML, patients with high NCK1-AS1 expression had a significantly lower hemoglobin level than those with low NCK1-AS1 expression (P =0.036), furthermore, NCK1-AS1 high patients had shorter overall survival than NCK1-AS1low patients (P =0.0378). Multivariate analysis showed that NCK1-AS1 expression was an independent adverse factor in patients with non-M3 AML ( HR =2.392, 95% CI :1.089-5.255, P =0.030). In addition, NCK1 expression was also significantly upregulated in all AML, non-M3 AML and CN-AML patients compared with controls (P < 0.01, P < 0.01, P < 0.001, respectively). There was a certain correlation between NCK1-AS1 and NCK1 expression (r =0.37, P =0.0058).
CONCLUSION
High expression of NCK1-AS1 in AML indicates poor prognosis of AML patients.
Humans
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Leukemia, Myeloid, Acute/genetics*
;
RNA, Long Noncoding/genetics*
;
Oncogene Proteins/genetics*
;
Adaptor Proteins, Signal Transducing/genetics*
;
Prognosis
;
Male
;
Female
;
Middle Aged
;
Adult
;
Case-Control Studies
;
Clinical Relevance
6.Metformin exerts a protective effect on articular cartilage in osteoarthritis rats by inhibiting the PI3K/AKT/mTOR pathway
Tianjie XU ; Jiaxin FAN ; Xiaoling GUO ; Xiang JIA ; Xingwang ZHAO ; Kainan LIU ; Qian WANG
Chinese Journal of Tissue Engineering Research 2025;29(5):1003-1012
BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.
7.Expert consensus on intraoperative repositioning for patients with spine fracture and dislocation (version 2025)
Dongmei BIAN ; Ke SUN ; Ningbo CHEN ; Caixia BAI ; Miao WANG ; Yafeng QIAO ; Fei WANG ; Hong WANG ; Feng TIAN ; Mei YAN ; Meng BAI ; Linjuan ZHANG ; Liyan ZHAO ; Yaqing CUI ; Xue JIANG ; Leling FENG ; Ning NING ; Junqin DING ; Lan WEI ; Yonghua ZHAI ; Yu ZENG ; Zengmei ZHANG ; Jiqun HE ; Fenggui BIE ; Hong CHEN ; Zengyan WANG ; Li LI ; Li ZHANG ; Yaying ZHOU ; Bing SHAO ; Ying WANG ; Caixia XIE ; Yanfeng YAO ; Jingjing AN ; Wen SHI ; Xiongtao LIU ; Xiaoyan AN ; Ning NAN ; Lan LI ; Xiaohui GOU ; Qiaomei LI ; Xiuting WU ; Yuqin ZHANG ; Jing LIU ; Fusen XIANG ; Xu XU ; Na MEI ; Jiao ZHOU ; Shan FAN ; Qian WANG ; Shuixia LI
Chinese Journal of Trauma 2025;41(2):138-147
Spine fracture and dislocation are common traumatic spinal conditions that often require surgical intervention due to compromised spinal stability. Surgical approaches include anterior, posterior, and combined anterior-posterior spinal procedures. According to the specific surgical requirements, patients may be placed in the prone position or repositioned between prone and supine positions during surgery. Intraoperative repositioning has become an essential step in patient positioning. However, during repositioning, patients with spinal fracture and dislocation are at increased risk for complications such as hemodynamic instability, nerve injury, and pressure injuries to the skin and soft tissue. Notably, due to the instability of the spinal cord, even minor manipulations can further exacerbate the damage, potentially leading to severe outcomes like paraplegia. Although the current clinical guidelines provide instructive recommendations for standard position, there remains no specific protocols for intraoperative repositioning in patients with spine fracture and dislocation. With a concern for the lack of clinical studies on positioning techniques, risk prevention, and operational norms for special patients, no applicable guidelines or standards are available. A consensus was required to provide clinical reference, meet the requirements of surgical treatment, and minimize the safety risks of patients caused by improper placement of positions. Professional Committee of Operating Room Nursing of Shaanxi Nursing Association organized experts in nursing management and operating room nursing from major hospitals across China to formulate Expert consensus on intraoperative repositioning for patients with spinal fracture and dislocation ( version 2025). The consensus provides 11 recommendations covering pre-repositioning preparation, intraoperative maneuvers, and post-repositioning observation, aiming to provide references for clinical standardization of the intraoperative repositioning process and protection of patients′ safety.
8.Therapeutic effects and underlying mechanisms of Ganluqingwen formula on acute lung injury in mice
Xiang-Peng LI ; Feng-Sen LI ; Zheng LI ; Ling WANG ; Dan XU ; Qian-Qian LIANG
Medical Journal of Chinese People's Liberation Army 2025;50(7):868-875
Objective To investigate the therapeutic effects and underlying mechanisms of Ganluqingwen formula on lipopolysaccharide(LPS)-induced acute lung injury/acute respiratory distress syndrome(ALI/ARDS)in mice.Methods Fifty ICR mice were randomly divided into five groups:control,model,and Ganluqingwen formula(GLQW)low dose(7.10 g/kg),medium dose(15.21 g/kg),and high dose(30.42 g/kg)groups,with 10 mice per group.On days 1-3,mice in GLQW groups were daily gavaged with the corresponding dose of GLQW,while control and model groups received equal volumes of saline.On day 4,ALI/ARDS was induced in model and GLQW groups using intraperitoneal injection of LPS(20 mg/kg),while control group received an equal volume of PBS.At 24 h post-treatment,survival rate,wet-to-dry weight ratio(W/D)and lung histological changes(HE staining)were observed.Serum levels of tumor necrosis factor(TNF)-α,interferon gamma(IFN-γ),interleukin(IL)-4,IL-10,IL-12,as well as lung tissue levels of TNF-α,IFN-γ,IL-1β,IL-4,IL-6,IL-10 were measured by ELISA.Western blotting was used to determine the expression levels of NOD-like receptor thermal protein domain associated protein 3(NLRP3),cystatinase-1(Caspase-1),apoptosis-associated speck-like protein(ASC),and membrane perforating protein Gasdermin D(GSDMD)in lung tissue.Results No significant differences in survival rates were observed among the groups(P>0.05).Compared with control group,ELISA and Western blotting results showed that lung tissue W/D,IFN-γ,TNF-α,IL-4,IL-12,IL-1β,IL-6,NLRP3,ASC,and Caspase-1,GSDMD and serum IFN-γ,TNF-α,IL-4,IL-12 levels were significantly higher(P<0.05),and IL-10 levels in lung tissue and serum were significantly lower in mice of model group(P<0.05).Compared with model group,lung tissue W/D,IFN-γ,TNF-α,IL-1β,IL-4,IL-6,IL-12,NLRP3,ASC,Caspase-1,and GSDMD,and serum IFN-γ,TNF-α,IL-4,and IL-12 levels were significantly lower(P<0.05),and lung tissue IL-10 levels were significantly higher(P<0.05)in GLQW low,medium,and high dose groups,with high-dose group showing significantly higher level in serum IL-10(P<0.05).Compared with GLQW low-dose group,the lung tissue levels of IFN-γ,IL-6,NLRP3,ASC,Caspase-1,and GSDMD,and serum TNF-α were significantly lower(P<0.05),and lung and serum IL-10 levels were significantly higher in GLQW high-dose group(P<0.05).HE staining results showed that lung structure was clear and normal in control group;part of the lung interstitium was congested and hemorrhagic,and some of the fine bronchial periphery was infiltrated with inflammatory cells in model group;the phenomena of lung interstitial congestion and hemorrhage were reduced,and the degree of infiltration of inflammatory cells was alleviated in GLQW low-,medium-,and high-dose groups.Conclusion Ganluqingwen formula can delay the development of ALI/ARDS in mice by inhibiting NLRP3/Caspase-1/GSDMD pathway,thereby suppressing cellular pyroptosis.
9.Construction of A Mouse Model of Liver Cancer Resistant to PD-1 Monoclonal Antibody and Analysis of Its Metabolic Changes
Xin-ru NIU ; Xia WANG ; Zhi-ting SHU ; Zi-lan XU ; Xiao-li QIU ; Wei DAI ; Liang-qian ZHANG ; Xiang-liang DENG
Progress in Modern Biomedicine 2025;25(12):1931-1941,1954
Objective:To establish a mouse model of liver cancer resistant to PD-1 monoclonal antibody and analyze the changes in its metabolomics to explore the potential mechanism of drug resistance.Methods:BALB/c mice were randomly divided into control and treatment groups after being loaded with tumor,and a normal group was additionally set up.The normal and control groups were injected with saline,and the treatment group was injected with PD-1 monoclonal antibody,after which the mice in the treatment group were screened for drug resistant and response groups.Observed the drug-resistant situation,body mass,tumor growth and survival rate of mice in each group,calculate the spleen index.The pathological features of tumor tissues were observed by HE staining method.Serum metabolites were detected by non-targeted metabolomics.Finally,a bivariate Pearson correlation analysis was conducted between the differential serum metabolites and tumor size.Results:The tumor-bearing mouse model with PD-1 monoclonal antibody resistance was successfully established,and the drug resistance rate of the mice was 50%.Compared with the normal and response groups,mice in the resistant group showed an increase in body weight,a significant increase in tumor volume,a decrease in survival rate,and a significant increase in splenic index.There was less lymphocyte infiltration in the tumor tissue.Metabolomics analysis showed that the serum levels of glutamic acid and aspartic acid increased and malic acid decreased in the resistant mice compared with the response group,and these changes were closely related to the arginine biosynthesis pathway.Conclusions:The tumor-bearing mouse model with PD-1 monoclonal antibody resistance was successfully established.The changes in its peripheral serum metabolomics mainly involve arginine metabolism and the related changes of aspartate,malate and glutamate.
10.Metformin inhibits ferroptosis and improves cartilage damage in osteoarthritis model rats
Jiaxin FAN ; Xiang JIA ; Tianjie XU ; Kainan LIU ; Xiaoling GUO ; Hui ZHANG ; Qian WANG
Chinese Journal of Tissue Engineering Research 2025;29(30):6398-6408
BACKGROUND:Metformin is currently considered the first-line medication for the treatment of type 2 diabetes.Metformin may delay the progression of osteoarthritis,but its specific mechanism of action remains unclear.OBJECTIVE:To evaluate the therapeutic effects and the related action mechanisms of metformin on osteoarthritis in rats.METHODS:(1)Network pharmacology:Potential common targets for metformin,osteoarthritis,and ferroptosis were screened using the CTD,SwissTargetPrediction,GeneCards,and OMIM databases.After importing the targets into the STRING database,protein-protein interaction analysis was conducted to identify the key targets for metformin,osteoarthritis,and ferroptosis.(2)Molecular docking:P53 and its downstream factor SLC7A11 protein structures in PDB format were downloaded from the PDB database.The 2D structure of metformin was converted to a 3D structure,and molecular docking of metformin with the proteins was performed using Discovery Studio 2019 Client.(3)In vivo experiments:Thirty male SD rats were randomly divided into three groups(n=10).The blank group did not receive surgery.The osteoarthritis model was established using the modified Hulth method for the model and metformin groups.One day after the surgery,rats in the metformin group were gavaged with metformin 200 mg/kg per day,while the blank and model groups were gavaged with physiological saline.Treatment continued for 4 weeks.Hematoxylin-eosin staining and Safranin O-fast green staining were used to observe the pathological morphology and structure of the knee cartilage,and Mankin scoring was performed.ELISA was used to measure the levels of tumor necrosis factor-α and interleukin-6 in the serum.The microplate method was used to measure serum ferroptosis-related indicators,including glutathione,malondialdehyde,and Fe2+.Immunofluorescence staining,western blot assay,and real-time qPCR were used to detect the protein and mRNA expression of P53,SLC7A11,glutathione peroxidase 4,proteoglycans,and matrix metalloproteinase 13 in the cartilage tissue of the rats.RESULTS AND CONCLUSION:(1)A total of 96 intersecting targets among metformin,osteoarthritis,and ferroptosis were identified.After protein-protein interaction analysis,77 potential targets were found.Further screening identified the core targets as TP53,AKT1,JUN,interleukin-6,MYC,interleukin-1β,and tumor necrosis factor-α,among others.(2)Docking analysis results showed that metformin bound strongly and stably with P53 and its downstream factor SLC7A11.(3)In the model group,the knee cartilage surface was irregular,with cartilage tissue defects and reduced chondrocyte numbers.Compared to the model group,the knee cartilage structure damage in the metformin group was significantly improved,with a smoother cartilage surface and increased chondrocyte numbers.The Mankin score in the model group was significantly higher than that in the blank group,while the Mankin score in the intervention group was significantly lower than that in the model group.(4)Compared with the model group,the metformin group had significantly lower levels of tumor necrosis factor-α,interleukin-6,malondialdehyde,and Fe2+,and significantly higher glutathione levels.(5)Compared to the model group,the metformin group had significantly increased protein and mRNA expression of SLC7A11,glutathione peroxidase 4,and proteoglycans,and significantly decreased protein and mRNA expression of P53 and matrix metalloproteinase 13 in their cartilage tissue.(6)The results indicate that metformin can effectively improve cartilage damage in osteoarthritis rats and alleviate chondrocyte ferroptosis by inhibiting the aberrantly activated P53/SLC7A11/glutathione peroxidase 4 signaling pathway.This improvement in chondrocyte iron metabolism and lipid peroxidation response further reduces cartilage matrix degradation and prevents further cartilage damage and inflammatory response.

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