1.The Regulatory Effects and Mechanisms of Piezo1 Channel on Chondrocytes and Bone Metabolic Dysregulation in Osteoarthritis
Yan LI ; Tao LIU ; Yu-Biao GU ; Hui-Qing TIAN ; Lei ZHANG ; Bi-Hui BAI ; Zhi-Jun HE ; Wen CHEN ; Jin-Peng LI ; Fei LI
Progress in Biochemistry and Biophysics 2026;53(3):564-576
Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca2+, K+, and Na+, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca2+ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca2+ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca2+ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.
2.Study on the role and mechanism of SPP1+ macrophages in the formation of chronic renal allograft fibrosis
Zexin YANG ; Zeping GUI ; Junqi ZHANG ; Gang ZHANG ; Hao CHEN ; Li SUN ; Shuang FEI ; Min GU ; Zijie WANG
Organ Transplantation 2026;17(3):413-421
Objective To investigate the role and potential mechanism of secreted phosphoprotein 1 (SPP1)+ macrophages in the formation of chronic renal allograft fibrosis. Methods The expression features of SPP1+ macrophages in renal allografts of chronic allograft dysfunction (CAD) patients were analyzed based on single-cell transcriptome data of renal tissues from patients with CAD. Transcription factor VIPER analysis and DoRothEA transcription factor activity analysis were performed on the single-cell transcriptome data. Renal tissue samples were collected from kidney transplant recipients, including the CAD group (n=5) and the non-renal allograft fibrosis group (CTL group, n=5). A mouse model of chronic allograft rejection was established and divided into the allogeneic kidney transplantation group (CAD group, n=3) and the syngeneic kidney transplantation group (SYN group, n=3). Hematoxylin-eosin staining was used to detect renal tissue injury in mice, and Masson staining was used to detect renal tissue fibrosis. Immunofluorescence staining was performed to detect SPP1 expression in renal tissues of transplant recipients and mouse renal allografts. Bone marrow-derived macrophages (BMDMs) were extracted from mice and subjected to hypoxia stimulation. The expression of hypoxia-inducible factor (HIF)-1α and SPP1 was detected by Western blot, and SPP1 expression was detected by flow cytometry. BMDMs were transfected with HIF-1α overexpression plasmid and HIF-1α small interfering RNA (siRNA) followed by hypoxia intervention, and the expression of HIF-1α and SPP1 was detected by Western blot. Mouse aortic endothelial cells (MAECs) were co-cultured with the supernatant of BMDMs, and the expression of endothelial-mesenchymal transition (EndMT)-related markers was detected by Western blot and immunofluorescence. Results Single-cell transcriptome analysis showed that the proportion of SPP1+ macrophages in renal allograft tissues was significantly higher in the CAD group than in the CTL group (P<0.05). The renal injury score and the percentage of interstitial fibrotic area in the CAD group were significantly higher than those in the SYN group (both P<0.05). Immunofluorescence staining showed that the proportion of SPP1+ macrophages was increased in the CAD group compared with the CTL group, and also increased in the CAD group compared with the SYN group (both P<0.05). VIPER analysis and DoRothEA transcription factor activity analysis revealed activation of the hypoxia pathway and upregulated expression of transcription factors such as HIF-1α in SPP1+ macrophages. SPP1 expression was elevated in BMDMs under hypoxic conditions. Knockdown of HIF-1α inhibited hypoxia-induced SPP1 protein expression, whereas overexpression of HIF-1α upregulated SPP1 protein levels. After co-culture of hypoxia-induced BMDMs with MAECs, the expression levels of EndMT-related markers were increased. Conclusions SPP1+ macrophages differentiated under hypoxia are significantly infiltrated in the formation of chronic renal allograft fibrosis, and may promote renal allograft fibrosis by inducing EndMT in renal vascular endothelial cells.
3.Evaluation of CARIFS Score and Negative Antigen Conversion Rate of Qingxuan Daozhi Formula in Treatment of Influenza in Children (Heat Accumulation in Lung and Stomach Syndrome):A Multi-center Randomized Controlled Clinical Study
Jing WANG ; Liqun WU ; Tiegang LIU ; Yongning CAO ; Jing QIU ; Jing LI ; Huaqing TAN ; Ying ZHANG ; Xulei GOU ; Jia WANG ; Jing LI ; Haipeng CHEN ; Xueying QIN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Lin JIANG ; Yingqi XU ; Jianping LIU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(13):188-196
ObjectiveThis paper aims to observe the syndrome improvement and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children (heat accumulation in the lung and stomach syndrome). MethodsThrough a multi-center randomized controlled methodology design,confirmed influenza cases were collected from October 2022 to April 2023 in the pediatrics department of eight hospitals,such as Dongfang Hospital of Beijing University of Chinese Medicine. A total of 180 children with influenza and heat accumulation in the lung and stomach syndrome conforming to the standard were recruited through the clinic. The sick children meeting the inclusion criteria were randomly divided into groups by a block-randomized method. The children in the experimental group were treated with Qingxuan Daozhi formula for five days,and those in the control group were treated with Oseltamivir Phosphate Granules for five days. The primary efficacy indicator was the negative conversion rate of influenza antigen detection. Secondary efficacy indicators were the Canadian acute respiratory illness and flu scale (CARIFS) and the incidence of complications,severe cases, and critical cases. Follow-up observation was conducted on the day of enrollment,48 hours after medication,72 hours after medication, and (6+1) d after medication. ResultsOne hundred and eighty participants were randomly assigned to the experimental group (90 cases) or the control group (90 cases). All participants were followed up during the study. Comparison of influenza antigen detection results in the primary efficacy indicators showed that the average time of negative influenza antigen conversion in the experimental group was (5.29±1.25) d,and that in the control group was (5.40±1.68) d,without a statistically significant difference. After five days of intervention,52 cases in the experimental group and 51 cases in the control group converted to negative,without a statistically significant difference. CARIFS score results in the secondary efficacy indicators showed that during 72 hours after intervention,there were statistically significant differences between the experimental group and the control group in three dimensions, including headache,muscle soreness, and the need for extra care (P<0.05). On the (6+1) days after the intervention,the differences in both the experimental group and the control group were statistically significant in 10 dimensions, including sore throat,bad sleep,uncomfortable feeling,poor spirit and fatigue,crying more than usual,the need for extra care,symptom,function,influence on parents,and total score (P<0.05). The comparison results within the group in the dimensional scores of symptom, function, and influence on parents,as well as the CARIFS total score showed that with the delay of follow-up time,scores of both groups decreased significantly,with a statistically significant difference (P<0.01). Inter-group comparison results showed that the mean score of the experimental group was higher than that of the control group at the time of enrollment. With the progress of intervention,the score of the experimental group was significantly decreased compared with that of the control group. At the end of follow-up,the mean score of the experimental group was lower than that of the control group,with no statistically significant difference. In terms of the incidence of complications,severe cases, and critical cases, there were no complications,severe cases, and critical cases in the two groups,without a statistically significant difference. ConclusionThe symptom improvement effect and negative antigen conversion rate of Qingxuan Daozhi formula in the treatment of influenza in children (heat accumulation in the lung and stomach syndrome) are not inferior to Oseltamivir Phosphate granules, and children's acceptance is better. It can be more widely used in clinical treatment of influenza in children (heat accumulation in the lung and stomach syndrome).
4.Clinical Efficacy of Xiaoji Hufei Formula in Protecting Children with Close Contact Exposure to Influenza: A Multicenter,Prospective, Non-randomized, Parallel, Controlled Trial
Jing WANG ; Jianping LIU ; Tiegang LIU ; Hong WANG ; Yingxin FU ; Jing LI ; Huaqing TAN ; Yingqi XU ; Yanan MA ; Wei WANG ; Jia WANG ; Haipeng CHEN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Liqun WU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(21):223-230
ObjectiveTo evaluate the efficacy and safety of Xiaoji Hufei Formula in protecting children with close contact exposure to influenza, and to provide reference and evidence-based support for better clinical prevention and treatment of influenza in children. MethodsA multicenter, prospective, non-randomized, parallel, controlled trial was conducted from October 2021 to May 2022 in five hospitals, including Dongfang Hospital of Beijing University of Chinese Medicine. Confirmed influenza cases and influenza-like illness (ILI) cases were collected, and eligible children with close contact exposure to these cases were recruited in the outpatient clinics. According to whether the enrolled close contacts were willing to take Xiaoji Hufei formula for influenza prevention, they were assigned to the observation group (108 cases) or the control group (108 cases). Follow-up visits were conducted on days 7 and 14 after enrollment. The primary outcomes were the incidence of ILI and the rate of laboratory-confirmed influenza. Secondary outcomes included traditional Chinese medicine (TCM) symptom score scale for influenza, influenza-related emergency (outpatient) visit rate, influenza hospitalization rate, and time to onset after exposure to influenza cases. ResultsA total of 216 participants were enrolled, with 108 in the observation group and 108 in the control group. Primary outcomes: (1) Incidence of ILI: The incidence was 12.0% (13/108) in the observation group and 23.1% (25/108) in the control group, with the observation group showing a significantly lower incidence (χ2=4.6, P<0.05). (2) Influenza confirmation rate: 3.7% (4/108) in the observation group and 4.6% (5/108) in the control group, with no statistically significant difference. Secondary outcomes: (1) TCM symptom score scale: after onset, nasal congestion and runny nose scores differed significantly between the two groups (P<0.05), while other symptoms such as fever, sore throat, and cough showed no significant differences. (2) Influenza-related emergency (outpatient) visit rate: 84.6% (11 cases) in the observation group and 96.0% (24 cases) in the control group, with no significant difference. (3) Time to onset after exposure: The median onset time after exposure to index patients was 7 days in the observation group and 4 days in the control group, with a statistically significant difference (P<0.05). ConclusionIn previously healthy children exposed to infectious influenza cases under unprotected conditions, Xiaoji Hufei formula prophylaxis significantly reduced the incidence of ILI. Xiaoji Hufei Formula can be recommended as a specific preventive prescription for influenza in children.
5.Clinical Efficacy of Xiaoji Hufei Formula in Protecting Children with Close Contact Exposure to Influenza: A Multicenter,Prospective, Non-randomized, Parallel, Controlled Trial
Jing WANG ; Jianping LIU ; Tiegang LIU ; Hong WANG ; Yingxin FU ; Jing LI ; Huaqing TAN ; Yingqi XU ; Yanan MA ; Wei WANG ; Jia WANG ; Haipeng CHEN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Liqun WU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(21):223-230
ObjectiveTo evaluate the efficacy and safety of Xiaoji Hufei Formula in protecting children with close contact exposure to influenza, and to provide reference and evidence-based support for better clinical prevention and treatment of influenza in children. MethodsA multicenter, prospective, non-randomized, parallel, controlled trial was conducted from October 2021 to May 2022 in five hospitals, including Dongfang Hospital of Beijing University of Chinese Medicine. Confirmed influenza cases and influenza-like illness (ILI) cases were collected, and eligible children with close contact exposure to these cases were recruited in the outpatient clinics. According to whether the enrolled close contacts were willing to take Xiaoji Hufei formula for influenza prevention, they were assigned to the observation group (108 cases) or the control group (108 cases). Follow-up visits were conducted on days 7 and 14 after enrollment. The primary outcomes were the incidence of ILI and the rate of laboratory-confirmed influenza. Secondary outcomes included traditional Chinese medicine (TCM) symptom score scale for influenza, influenza-related emergency (outpatient) visit rate, influenza hospitalization rate, and time to onset after exposure to influenza cases. ResultsA total of 216 participants were enrolled, with 108 in the observation group and 108 in the control group. Primary outcomes: (1) Incidence of ILI: The incidence was 12.0% (13/108) in the observation group and 23.1% (25/108) in the control group, with the observation group showing a significantly lower incidence (χ2=4.6, P<0.05). (2) Influenza confirmation rate: 3.7% (4/108) in the observation group and 4.6% (5/108) in the control group, with no statistically significant difference. Secondary outcomes: (1) TCM symptom score scale: after onset, nasal congestion and runny nose scores differed significantly between the two groups (P<0.05), while other symptoms such as fever, sore throat, and cough showed no significant differences. (2) Influenza-related emergency (outpatient) visit rate: 84.6% (11 cases) in the observation group and 96.0% (24 cases) in the control group, with no significant difference. (3) Time to onset after exposure: The median onset time after exposure to index patients was 7 days in the observation group and 4 days in the control group, with a statistically significant difference (P<0.05). ConclusionIn previously healthy children exposed to infectious influenza cases under unprotected conditions, Xiaoji Hufei formula prophylaxis significantly reduced the incidence of ILI. Xiaoji Hufei Formula can be recommended as a specific preventive prescription for influenza in children.
6.Comparative analysis of characteristics and functions of exosomes from human induced pluripotent stem cell-derived platelets and apheresis platelets
Weihua HUANG ; Yan ZANG ; Aihua QIN ; Ziyang FENG ; Heshan TANG ; Fei GUO ; Chuyan WU ; Qiu SHEN ; Baohua QIAN ; Haihui GU ; Zhanshan CHA
Chinese Journal of Blood Transfusion 2025;38(9):1154-1161
Objective: To compare the biological characteristics of human induced pluripotent stem cell-derived platelet exosomes (hiPSC-Plt-Exos) with those of conventional apheresis platelet exosomes (Plt-Exos), specifically focusing on their differential abilities to enhance the proliferation and migration of human umbilical cord mesenchymal stem cells (hUC-MSCs). Methods: Exosomes were isolated from hiPSC-derived Plt and apheresis Plt concentrate using size exclusion chromatography. These exosomes were then characterized through nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and Western blotting. Co-culture experiments into hUC-MSCs were conducted with hiPSC-Plt-Exos and apheresis Plt-Exos, respectively. Their effects on the proliferation and migration of hUC-MSCs were assessed via cell proliferation assays and scratch tests. Results: hiPSC-Plt-Exos and apheresis Plt-Exos exhibited comparable particle sizes, morphological features (such as the characteristic cup-shaped structure), and surface markers (including CD9 and HSP70). Notably, hiPSC-Plt-Exos demonstrated a significantly greater ability to enhance the proliferation and migration of hUC-MSCs compared to apheresis Plt-Exos (P<0.05). These differences provide critical comparative data for their application in various clinical contexts. Conclusion: This study establishes a theoretical foundation for developing precise therapeutic strategies based on hiPSC-Plt-Exos. Furthermore, it underscores the necessity of selecting the appropriate type of exosomes according to the specific disease microenvironment to achieve optimal therapeutic outcomes.
7.Influencing factors and nursing enlightenment of bone metabolism abnormalities in lung transplant reci-pients
Yandie WANG ; Fei ZENG ; Jiangshuyuan LIANG ; Peipei GU
Chinese Journal of Nursing 2025;60(6):703-709
Objective To explore the current status of bone metabolism abnormalities after lung transplantation and its influencing factors,and provide scientific references for the formulation of nursing intervention measures.Methods A retrospective analysis of the clinical data of 125 patients undergoing lung transplantation at a lung transplant center from June 2021 to August 2023 was conducted.The paired sample t-test was used to compare the trends in bone mineral density(BMD)before and after transplantation.Postoperative BMD was compared to domestic age-matched norms using the single sample t-test.Univariate analysis and unordered multinomial logistic regression were employed to identify factors associated with bone metabolism abnormalities post-transplantation.Results The incidence of bone metabolism abnormalities after lung transplantation was 62.4%,with osteopenia and osteoporosis rates at 36.8%and 25.6%,respectively.The BMD of the femoral neck and left hip joint generally showed a declining trend post-transplantation(P<0.001).Additionally,both male and female patients had lower BMD than the age-matched national norms(P<0.001).Logistic regression analysis indicated that pre-transplant Activities of Daily Living(ADL)score was a significant factor for post-transplant osteopenia(OR 0.957,95%CI 0.928~0.987).Female gender,pre-transplant low body weight,obesity,reduced forced expiratory volume in one second/forced vital capacity percentage(FEV1/FVC),and ADL score were significant factors for post-transplant osteoporosis,with OR values of 7.181,7.521,15.465,0.960,0.964;95%CI were 1.287~40.061,2.039~27.738,1.158~206.586,0.937~0.983,0.930~0.999,respectively.Conclusion Bone metabolism abnormalities are common in patients post-lung transplantation.Healthcare providers should pay particular attention to female patients,those with low pre-transplant body weight,obesity,reduced FEV1/FVC,and lower ADL scores.Timely,individualized,and multidisciplinary interventions are crucial to slowing postoperative bone loss,reducing the incidence of bone metabolism abnormalities,and improving the health-related quality of life for these patients.
8.Prevention,control monitoring of environmental carbapenem-resistant Klebsiella pneumoniae in intensive care unit of a three-A hospital
Yuan LI ; Guangnan SHAO ; Keju GU ; Liang TIAN ; Chunyan LI ; Yun LIU ; Huan TANG ; Fei WANG ; Wei JI
Chinese Journal of Nosocomiology 2025;35(9):1391-1395
OBJECTIVE To carry out regular monitoring of carbapenem-resistant Klebsiella pneumoniae(CRKP)contamination status in the environment of intensive care unit(ICU)and take targeted prevention and control measures so as to reduce the incidence of hospital-associated infections with multidrug-resistant organisms(MDROs).METHODS The surfaces of surroundings of the patients who were colonized and infected with CRKP in the ICU of grade A tertiary hospital of Shanghai and the hands of relevant staff were sampled by stages from Jan 1,2021 to Jun 30,2024.The distribution of the CRKP strains in the surroundings were analyzed according to the locations positive for CRKP,and the disinfection measures were accordingly and continuously modified.The trend of isolation rate of CRKP strains from the ICU patients was analyzed during the time period when the measures were implemented.RESULTS Totally 266 environmental samples were collected during the baseline period(from Jan.1 2021 to Dec.31 2021),265 during intervention period(from Jan.1 2022 to Dec.31 2023),274 during con-solidation period(from Jan.1 to Jun.30 2024);the isolation rates of the CRKP strains were 4.51%,4.91%and 3.65%,respectively.The isolation rate of the strains was highest from the bed unit(10.40%),followed by the article for public use(6.74%),articles used by health care workers(2.98%)and diagnosis and treatment arti-cles(1.91%).The isolation rate of CRKP of the patients was 24.75%during the baseline period,15.48%during the intervention period,5.69%during the consolidation period,showing a continuously downward trend(x2=30.330,P<0.001).CONCLUSION It is necessary to regularly carry out the environmental monitoring of CRKP strains,seek for the weak links of environmental disinfection and implement the intensified prevention and control measures so as to reduce the incidence of CRKP infection,which may provide theoretical bases for effective control of the CRKP strains.
9.Experiences and implications of healthy weight management policies in Japan,South Korea,and Singapore:Based on the ICCC framework
Yao-ling WANG ; Chang YANG ; Xue-fei GU ; Xue LI ; Wu-dong GUO
Chinese Journal of Health Policy 2025;18(7):27-34
Objective:This study aims to analyze the weight management policy practices in Japan,South Korea,and Singapore to provide international references for improving China's weight health management and metabolic disease prevention system.Methods:Based on the Innovative Care for Chronic Conditions Framework(ICCC),we conducted a literature review and policy analysis methods of domestic and international policies and publications on weight management,systematically analyzing and summarizing relevant strategies and practices to extract key insights in Japan,South Korea,and Singapore.Results:All three countries have established a multi-level collaborative governance system:at the macro level,they built institutional foundations through legislation,cross-sectoral collaboration,and diversified financing;at the meso level,they enhanced management efficiency via comprehensive medical services,multidisciplinary coordination,and smart information systems,while community-level initiatives fostered supportive environments through health education and environmental modifications;at the micro level,they emphasized personalized interventions and family involvement to strengthen self-management capabilities.Conclusion:China can learn from these neighboring countries'experiences to develop a multi-tiered prevention system,strengthen primary care capacity,improve medical security mechanisms,and facilitate a shift from disease treatment to health management,ultimately constructing a weight management solution with Chinese characteristics.
10.Novel Structural Features of Isoflavone Synthase from Medicago truncatula Shed Light on Its Unique Enzymatic Mechanism
Chao SHI ; Zhao-Yang YE ; Fei XU ; Xiang-Ning DU ; Zhang-Xin CHEN ; Ming-Yue GU ; Jie DENG ; Wei WANG ; Liang-Yu LIU ; Mei-Ying WANG ; Xiao-Dong SU ; He-Li LIU ; Ming-Ying SHANG ; Li-Xin HUANG ; Zhen-Zhan CHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(8):1204-1213,中插1-中插6
Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

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