1.Effect of tirofiban on prognosis in acute anterior circulation large vessel occlusion stroke patients with unsuccessful recanalization after endovascular treatment
Anyu LIAO ; Minxing ZHAO ; Kang YUAN ; Kangmo HUANG ; Zhiliang GUO ; Xianjun HUANG ; Zhenhui DUAN ; Rui LIU ; Guodong XIAO ; Wenhua LIU ; Zhiming ZHOU ; Wusheng ZHU
Chinese Journal of Cerebrovascular Diseases 2025;22(8):515-523,578
Objective To analyze the effects of intravenous tirofiban following endovascular treatment on the prognosis of patients with acute anterior circulation large vessel occlusion stroke who did not achieve successful recanalization.Methods This retrospective study included consecutive patients with acute anterior circulation ischemic stroke who underwent endovascular treatment but did not achieve successful recanalization.These patients were retrospectively enrolled from the Department of Neurology at Nanjing Jinling Hospital,Affiliated Hospital of Medical School,Nanjing University,the Second Affiliated Hospital of Soochow University,Wuhan No.1 Hospital,and Yijishan Hospital of Wannan Medical College(the First Affiliated Hospital of Wannan Medical College)between January 2015 and April 2023.Baseline and clinical data were collected including age,sex,medical history(hypertension,diabetes,atrial fibrillation,hyperlipidemia),personal history(smoking and drinking),National Institutes of Health stroke scale(NIHSS)score at admission,trial of Org 10172 in acute stroke treatment(TOAST)classification(large artery atherosclerosis,cardioembolism,or other types),Alberta stroke program early CT score(ASPECTS)on admission,intravenous thrombolysis,onset-to-puncture time(OTP),collateral circulation status(poor collaterals:American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology[ASTIN/SIR]score 0-2;good collateral:ASTIN/SIR score 3-4),procedure duration(from femoral or radial artery puncture to device removal),occlusion site,number of passes for thrombus retrieval,and post-procedural modified thrombolysis in cerebral infarction(mTICI)grade.Patients were divided into a tirofiban group and a non-tirofiban group based on whether they received post-procedural intravenous tirofiban.The primary outcome is a favorable functional outcome at 90-day since onset(modified Rankin scale[mRS]score ≤ 3).Safety outcomes included mortality at 90-day since onset(mRS score 6),any intracranial hemorrhage within 24 h post-procedure,and symptomatic intracranial hemorrhage within 24 h post-procedure.1∶1 propensity score matchings using the nearest neighbor method was performed based on variables with P<0.05 in the comparison between the tirofiban and non-tirofiban groups.Differences in primary and safety outcomes between the matched groups were compared.Univariate and multivariate Logistic regression analyses were conducted with favorable outcomes at 90 days as the dependent variable to evaluate the effect of intravenous tirofiban administration after endovascular therapy on 90-day prognosis in patients without successful recanalization.Results A total of 356 patients without successful recanalization after endovascular treatment were included,comprising 195 males and 161 females,with a median age of 70(61,78)years(32-92 years).Among them,76 and 280patients were assigned to the tirofiban and non-tirofiban groups,respectively.At 90 days,114 patients had favorable outcomes,while 242 had unfavorable outcomes.(1)Before the 1∶1 propensity score matching,significant differences were observed between the tirofiban and non-tirofiban groups in terms of admission NIHSS score,ASPECTS,good collateral circulation,intravenous thrombolysis,and mTICI grade(all P<0.05).After 1∶1 propensity score matching,66 matched pairs(132 patients)were obtained.No significant differences in the baseline and clinical characteristics were found between the two groups after matching(all P>0.05).(2)After 1∶1 matching,a significant difference was observed in the rate of favorable outcomes at 90 days between the two groups(48.5%[32/66]vs.30.3%[20/66],P=0.033)after propensity score matching,while no significant differences were found in 90-day mortality,intracranial hemorrhage within 24h,or symptomatic intracranial hemorrhage within 24h(all P>0.05).(3)Univariate analysis after 1∶1 matching indicated that age,atrial fibrillation,smoking history,admission NIHSS score,M2 segment middle cerebral artery occlusion,good collateral circulation,number of passes for thrombus retrieval,and tirofiban treatment were factors influencing favorable outcomes at 90 days.Multivariate Logistic regression analysis showed that younger age(aOR,0.942,95%CI 0.906-0.978,P=0.002),lower admission NIHSS score(aOR,0.855,95%CI 0.777-0.941,P=0.001),good collateral circulation(aOR,5.534,95%CI 2.141-14.301,P<0.01),tirofiban treatment(aOR,2.774,95%CI 1.092-7.046,P=0.032),and M2 segment MCA occlusion(reference:internal carotid artery occlusion;aOR,4.874,95%CI 1.428-16.632,P=0.011)were independent predictors of favorable outcomes at 90 days.Conclusions Intravenous tirofiban administration after endovascular therapy may improve 90-day neurological outcomes in patients with acute anterior circulation large vessel occlusion stroke who did not achieve successful recanalization without increasing the risk of hemorrhage.Further large-scale randomized controlled trials are warranted to validate these findings.
2.Analysis of the influencing factors of early neurological deterioration and short-term prognosis in minor acute ischemic stroke patients
Longsheng CHU ; Xianjun HUANG ; Chenglei WANG ; Bohao WEI ; Yuepei GAO ; Ameng LI ; Ke YANG ; Junfeng XU ; Xianjin SHANG ; Zhiming ZHOU
Chinese Journal of Cerebrovascular Diseases 2025;22(8):524-536
Objective To investigate the influencing factors associated with early neurological deterioration(END)in patients with minor acute ischemic stroke(mAIS),develop a clinical prediction model for END,and identify independent risk factors for 90-day neurological functional outcomes after stroke.Methods mAIS patients admitted consecutively to the Department of Neurology,Yijishan Hospital of Wannan Medical College(the First Affiliated Hospital of Wannan Medical College),from July 2023 to July 2024 were retrospectively collected.A minor ischemic stroke was defined as acute ischemic stroke with a National Institutes of Health stroke scale(NIHSS)score≤5 on admission.Baseline,clinical,and imaging data of all mAIS patients were collected and recorded,including demographic information(age,sex),past medical history(hypertension,diabetes mellitus,hyperlipidemia,coronary heart disease,atrial fibrillation),smoking history,alcohol consumption,baseline blood pressure,pre-onset modified Rankin scale(mRS),NIHSS scores at admission and during hospitalization(24 hours,48 hours,72 hours after admission),motor component subscore of the NIHSS scores,NIHSS scores at discharge,trial of Org 10172 in acute stroke treatment(TOAST)classification,laboratory indicators(fasting blood glucose,hemoglobin A1c[HbA1c],total cholesterol,triglycerides,high-density lipoprotein,low-density lipoprotein),clinical treatment information(intravenous thrombolysis,mono antiplatelet therapy,dual antiplatelet therapy,anticoagulation therapy)and length of stay.The status of stenosis and occlusion in the culprit vessel were assessed based on imaging results.Mild-to-moderate stenosis was defined as a stenosis rate of 0%to 69%,severe stenosis as a stenosis rate of 70%to 99%,and occlusion as complete interruption of the supplying artery.END was defined as an increase in NIHSS score of ≥2 points from baseline within 72 hours after admission,combined with an increase of at least 1 point in the motor score compared to the score at admission.Prognosis was assessed via telephone follow-ups at 90-day after onset using mRS score,with an mRS score ≤ 2 indicating a favorable outcome and an mRS score>2 indicating a poor outcome.Variables with P<0.05 in the univariate analysis were incorporated into multivariate Logistic regression analysis to identify the independent risk factors for END in mAIS patients.A nomogram model was constructed,and calibration curves along with decision curve analysis were plotted to evaluate the model's goodness-of-fit and clinical utility.Univariate and multivariate Logistic regression analyses were performed to identify factors associated with poor 90-day functional outcome after mAIS.Results(1)A total of 826 patients were included,aged 33-94 years,with a median age of 67(57,76)years.There were 571 males and 255 females.The NIHSS score at admission ranged from 0 to 5,with a median NIHSS score at admission of 3(2,4).The NIHSS motor subscore at admission ranged from 0 to 5,with a median baseline NIHSS motor score of 2(0,2).Among them,119 patients(14.4%)were in the END group and 707 patients(85.6%)were included in the non-END group.At 90days after stroke,744 patients(90.1%)had a favorable outcome,while 82 patients(9.9%)had a poor outcome.(2)Univariate analysis showed that there were statistically significant differences between the END group and the non-END group in terms of HbA1c,fasting blood glucose,baseline NIHSS score,baseline NIHSS motor subscore,history of alcohol consumption,diabetes mellitus,culprit vessel stenosis and occlusion,and TOAST classification(all P<0.05).Statistically significant differences were observed between the favorable outcome group and the poor outcome group in HbA1c,fasting blood glucose,incidence of END,baseline NIHSS score,discharge NIHSS score,culprit vessel stenosis and occlusion,TOAST classification,and history of alcohol consumption(all P<0.05).(3)Multivariate Logistic regression analysis indicated that mAIS patients with severe stenosis of the culprit vessel(OR,5.88,95%CI2.32-14.91,P<0.01),occlusion of the culprit vessel(OR,5.74,95%CI 2.25-14.62,P<0.01),history of alcohol consumption(OR,5.59,95%CI3.41-9.17,P<0.01),elevated HbA1c(OR,1.67,95%CI 1.35-2.08,P<0.01),and higher baseline NIHSS motor score(OR,1.43,95%CI 1.08-1.89,P=0.012)had an increased risk of END.A higher discharge NIHSS score(OR,2.59,95%CI 1.89-3.57,P<0.01)and the occurrence of END(OR,18.42,95%CI 5.13-66.18,P<0.01)were associated with poor 90-day functional outcome after mAIS.(4)The nomogram model constructed based on independent risk factors of END in mAIS patients demonstrated an AUC of 0.78(95%CI 0.73-0.83)for predicting END,with a sensitivity of 0.8 and a specificity of 0.7.The model showed good calibration,and the Hosmer-Lemeshow test indicated good agreement between predicted and observed values(P=0.333).Decision curve analysis revealed that the model provided a high net benefit across a range of high-risk thresholds(0.1-0.7),suggesting its potential clinical utility.Conclusions Severe stenosis of the culprit vessel,occlusion of the culprit vessel,glycated hemoglobin levels,baseline NIHSS motor subscale scores,and history of alcohol consumption are independent risk factors for END in patients with mAIS.The nomogram model constructed based on these factors demonstrated good predictive performance.END and NIHSS scores at discharge are independent predictors of poor 90-day outcomes in patients with mAIS.
3.Analysis of transcriptome and chromatin accessibility changes during the differentiation of human embryonic stem cells into neural progenitor cells
Linying LI ; Xiaodong CAI ; Ran TONG ; Chen YANG ; Zhiming WANG ; Xiaoyu HE ; Ziyue MA ; Feng ZHANG ; Lingjie LI ; Junmei ZHOU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(4):387-403
Objective·To investigate the changes in transcriptome and chromatin accessibility during the differentiation of human embryonic stem cells(hESCs)into neural progenitor cells(NPCs)using in vitro differentiation models and high-throughput multi-omics sequencing technologies.Methods·hESCs were first induced to differentiate into NPCs in vitro using the embryoid body formation method,and cells at both stages were collected.The cell phenotypes were identified by reverse transcription-quantitative real-time PCR(RT-qPCR)and immunofluorescence(IF)staining.Transcriptome sequencing(RNA-seq)was conducted to detect and analyze the differentially expressed genes(DEGs)between hESCs and NPCs.The assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)was employed to assess chromatin accessibility changes between hESCs and NPCs.Motif enrichment analysis was performed on differentially accessible chromatin regions to discover potential regulatory transcription factors.Finally,an integrated analysis of RNA-seq and ATAC-seq data and the protein-protein interaction(PPI)network were performed to identify key genes and regulatory pathways involved in the early stages of neural differentiation in vitro.Results·Both RT-qPCR and IF results indicated that the expression levels of pluripotency markers(NANOG and POU5F1)were high at the hESC stage but significantly decreased at the NPC stage,while early neural differentiation markers(PAX6,SOX1,and NES)were minimally expressed at the hESC stage but markedly upregulated at the NPC stage.RNA-seq analysis revealed that compared to the hESC stage,there were 5 597 genes upregulated and 3 654 genes downregulated at the NPC stage.Gene function enrichment analysis showed that the upregulated genes at the NPC stage were enriched in the functions related to neural development.ATAC-seq analysis demonstrated a total of 27 491 genomic regions had significant changes in chromatin accessibility during the differentiation from hESC to NPC,with 12 381 regions showing increased accessibility and 15 110 regions showing decreased accessibility.Motif enrichment analysis revealed that transcription factor genes such as DLX1 and LHX2 might play an important role in the differentiation process from hESCs into NPCs.Integrated analysis of RNA-seq and ATAC-seq data revealed that overlapping genes with high expression at the NPC stage were mainly enriched in axon guidance,forebrain development,and neuron migration.After neural differentiation,the expression levels of CTNND2 and LHX2 genes increased,and the chromatin accessibility of related genomic regions also increased.PPI network analysis indentified candidate downstream genes including PRKACA,CDH2,and ERBB4.Conclusion·The in vitro differentiation model of hESCs combined with high-throughput multi-omics sequencing technologies can be used to depict the changes in transcriptome and chromatin accessibility during the differentiation of hESCs into NPCs.In this process,the expression levels of genes related to axon guidance,forebrain development,and neuronal migration pathways increase and related chromatin accessibility is enhanced.
4.Research progress in in vitro test methods and tiered strategies for eye irritation
Jiasheng BAO ; Mengyuan LI ; Lixia HUANG ; Bingzhen PAN ; Zhiming ZHOU
Chinese Journal of Pharmacology and Toxicology 2025;39(5):370-379
Assessment of eye irritation potential is part of the international regulatory requirements for safety testing of chemicals.Because of increasing concerns about to animal welfare in recent years,the development of alternative methods to reduce the number of animals used in eye irritation tests has become imperative.This article introduces in vitro test methods based on organotypic models,cell lines and reconstructed human cornea-like epithelium(RhCE),and analyzes strengths and weaknesses of the individual in vitro test methods.To overcome the limitations of the individual in vitro test methods,it is recommended that tiered testing strategies be adopted that combine the strengths of individual in vitro test methods to address the required ranges of irritation potential.Future applications of new technolo-gies such as genomics,proteomics and computational models in the assessment of eye irritation poten-tial are also predicted.
5.Analysis of transcriptome and chromatin accessibility changes during the differentiation of human embryonic stem cells into neural progenitor cells
Linying LI ; Xiaodong CAI ; Ran TONG ; Chen YANG ; Zhiming WANG ; Xiaoyu HE ; Ziyue MA ; Feng ZHANG ; Lingjie LI ; Junmei ZHOU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(4):387-403
Objective·To investigate the changes in transcriptome and chromatin accessibility during the differentiation of human embryonic stem cells(hESCs)into neural progenitor cells(NPCs)using in vitro differentiation models and high-throughput multi-omics sequencing technologies.Methods·hESCs were first induced to differentiate into NPCs in vitro using the embryoid body formation method,and cells at both stages were collected.The cell phenotypes were identified by reverse transcription-quantitative real-time PCR(RT-qPCR)and immunofluorescence(IF)staining.Transcriptome sequencing(RNA-seq)was conducted to detect and analyze the differentially expressed genes(DEGs)between hESCs and NPCs.The assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)was employed to assess chromatin accessibility changes between hESCs and NPCs.Motif enrichment analysis was performed on differentially accessible chromatin regions to discover potential regulatory transcription factors.Finally,an integrated analysis of RNA-seq and ATAC-seq data and the protein-protein interaction(PPI)network were performed to identify key genes and regulatory pathways involved in the early stages of neural differentiation in vitro.Results·Both RT-qPCR and IF results indicated that the expression levels of pluripotency markers(NANOG and POU5F1)were high at the hESC stage but significantly decreased at the NPC stage,while early neural differentiation markers(PAX6,SOX1,and NES)were minimally expressed at the hESC stage but markedly upregulated at the NPC stage.RNA-seq analysis revealed that compared to the hESC stage,there were 5 597 genes upregulated and 3 654 genes downregulated at the NPC stage.Gene function enrichment analysis showed that the upregulated genes at the NPC stage were enriched in the functions related to neural development.ATAC-seq analysis demonstrated a total of 27 491 genomic regions had significant changes in chromatin accessibility during the differentiation from hESC to NPC,with 12 381 regions showing increased accessibility and 15 110 regions showing decreased accessibility.Motif enrichment analysis revealed that transcription factor genes such as DLX1 and LHX2 might play an important role in the differentiation process from hESCs into NPCs.Integrated analysis of RNA-seq and ATAC-seq data revealed that overlapping genes with high expression at the NPC stage were mainly enriched in axon guidance,forebrain development,and neuron migration.After neural differentiation,the expression levels of CTNND2 and LHX2 genes increased,and the chromatin accessibility of related genomic regions also increased.PPI network analysis indentified candidate downstream genes including PRKACA,CDH2,and ERBB4.Conclusion·The in vitro differentiation model of hESCs combined with high-throughput multi-omics sequencing technologies can be used to depict the changes in transcriptome and chromatin accessibility during the differentiation of hESCs into NPCs.In this process,the expression levels of genes related to axon guidance,forebrain development,and neuronal migration pathways increase and related chromatin accessibility is enhanced.
6.Treating premature ejaculation combined with anxiety and depression based on the "four-dimensional integration" of the "holism of body and spirit" theory
Yi WEI ; Zhiming HONG ; Junfeng QIU ; Zilong CHEN ; Hao KUANG ; Yangling ZENG ; Quan WANG ; Wenbin ZHOU
Journal of Beijing University of Traditional Chinese Medicine 2025;48(3):418-423
Premature ejaculation refers to a sexual dysfunction in which men experience a short intravaginal ejaculation latency and a lack of control over ejaculation during sexual activity. The onset of this condition is often accompanied by anxiety and depression, which can seriously affect the quality of the patient′s sexual life and the relationship between partners. Based on the "integration of body and spirit" theory in traditional Chinese medicine, our team believes that this condition is a comorbidity of physical and spiritual factors. We propose that the core pathogenesis of this disease lies in the "loss of form and essence, impairment of spirit, and depression of the mind, "while the primary treatment principle involves "nourishing form and regulating spirit." As a result, a new diagnosis and treatment approach of "four-dimensional integration" is summarized in this study. The disease is treated through the four dimensions of shape, body, spirit, and emotion. Traditional Chinese medicine is used to adjust the shape in cases where the physical form is damaged. For individuals with depression of heart and liver qi, the treatment focuses on soothing the heart and smoothing liver qi, and the modified Wangyou Powder and Xuanzhi Decoction is used. In cases where the heart and kidney function are compromised, the treatment involves nourishing both the heart and kidney while restoring interaction between the heart and the kidney, and modified Jihuo Yansi Elixir is used. To reduce the sensitivity of the glans penis, the patient′s body is washed with a traditional Chinese medicine formula, and a delicate fumigation formula is decocted for external washing. For those who are not in tune with their god, psychological counseling can be used to regulate their spirit and advocate "self-partner" and psychotherapy. If there are issues with intimacy, partners should focus on cooperating during foreplay, sexual intercourse, and post-coital interactions. Overall, the treatment aims to harmonize the body and spirit, addressing both physical and psychological factors through a comprehensive, multi-dimensional approach. This method provides new perspectives and ideas for the clinical diagnosis and treatment of this condition.
7.Development and challenges of mass spectrometry database for traditional Chinese medicine:A review
Wang YIJUN ; Yang ZHIMING ; Wu JUNXIAN ; Ma XIAOLI ; Zhou LI ; Li XIANG ; Ma BAIPING ; Qiu ZIDONG ; Kang LIPING
Science of Traditional Chinese Medicine 2025;3(3):210-221
Accurate characterization of the chemical composition of complex traditional Chinese medicine(TCM)is an essential foundation for the modern scientific interpretation of TCM principles.Mass spectrometry is the most dominant technique in current research on the material basis of TCM,offering the highest sensitivity and the richest information provision.Establishing mass spectrometry databases represents the most effective approach to facilitating the structural analysis of TCM chemical components.This paper systematically searches and reviews literature published from January 2005 to January 2025 through online databases such as China National Knowledge Infrastructure,PubMed,and Web of Science,using"mass spectrometry database"and"traditional Chinese medicine"as keywords.It reviews the current status of seven TCM chemical component mass spectrometry databases and seven natural product mass spectrometry databases.The key advancements of these mass spectrometry databases for natural products are summarized,detailing their characteristics,search methodologies,included information,and data sources.Additionally,challenges related to data quality,standardization,timely updates,database interaction,retrieval functionality,and data sharing and security are discussed in depth.Furthermore,the paper explores prospective development directions for TCM mass spectrometry databases,emphasizing the importance of open data sharing,technological innovation,and data security.Through this analysis,the paper aims to offer theoretical guidance and practical recommendations for the precise identification of TCM components,as well as for the construction and application of these databases.
8.Research progress in in vitro test methods and tiered strategies for eye irritation
Jiasheng BAO ; Mengyuan LI ; Lixia HUANG ; Bingzhen PAN ; Zhiming ZHOU
Chinese Journal of Pharmacology and Toxicology 2025;39(5):370-379
Assessment of eye irritation potential is part of the international regulatory requirements for safety testing of chemicals.Because of increasing concerns about to animal welfare in recent years,the development of alternative methods to reduce the number of animals used in eye irritation tests has become imperative.This article introduces in vitro test methods based on organotypic models,cell lines and reconstructed human cornea-like epithelium(RhCE),and analyzes strengths and weaknesses of the individual in vitro test methods.To overcome the limitations of the individual in vitro test methods,it is recommended that tiered testing strategies be adopted that combine the strengths of individual in vitro test methods to address the required ranges of irritation potential.Future applications of new technolo-gies such as genomics,proteomics and computational models in the assessment of eye irritation poten-tial are also predicted.
9.Zishen Huoxue decoction (ZSHX) alleviates ischemic myocardial injury (MI) via Sirt5-β-tubulin mediated synergistic mechanism of "mitophagy-unfolded protein response" and mitophagy.
Xing CHANG ; Siyuan ZHOU ; Yu HUANG ; Jinfeng LIU ; Yanli WANG ; Xuanke GUAN ; Qiaomin WU ; Zhiming LIU ; Ruxiu LIU
Chinese Journal of Natural Medicines (English Ed.) 2025;23(3):311-321
Zishen Huoxue decoction (ZSHX) enhances cardiomyocyte viability following hypoxic stress; however, its upstream therapeutic targets remain unclear. Network pharmacology and RNA sequencing analyses revealed that ZSHX target genes were closely associated with mitophagy and apoptosis in the mitochondrial pathway. In vitro, ZSHX inhibited pathological mitochondrial fission following hypoxic stress, regulated FUN14 domain-containing protein 1 (FUNDC1)-related mitophagy, and increased the levels of mitophagy lysosomes and microtubule-associated protein 1 light chain 3 beta II (LC3II)/translocase of outer mitochondrial membrane 20 (TOM20) expression while inhibiting the over-activated mitochondrial unfolded protein response. Additionally, ZSHX regulated the stability of beta-tubulin through Sirtuin 5 (SIRT5) and could modulate FUNDC1-related synergistic mechanisms of mitophagy and unfolded protein response in the mitochondria (UPRmt) via the SIRT5 and -β-tubulin axis. This targeting pathway may be crucial for cardiomyocytes to resist hypoxia. Collectively, these findings suggest that ZSHX can protect against cardiomyocyte injury via the SIRT5-β-tubulin axis, which may be associated with the synergistic protective mechanism of SIRT5-β-tubulin axis-related mitophagy and UPRmt on cardiomyocytes.
Mitophagy/drug effects*
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Tubulin/genetics*
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Animals
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Myocytes, Cardiac/metabolism*
;
Drugs, Chinese Herbal/pharmacology*
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Sirtuins/genetics*
;
Unfolded Protein Response/drug effects*
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Myocardial Ischemia/genetics*
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Rats
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Humans
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Rats, Sprague-Dawley
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Apoptosis/drug effects*
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Male
10.Metabolic engineering of Escherichia coli for de novo synthesis of L-theanine.
Siquan ZHOU ; Di ZHANG ; Meijuan XU ; Xian ZHANG ; Taowei YANG ; Zhiming RAO
Chinese Journal of Biotechnology 2025;41(9):3459-3472
L-theanine is an important natural non-protein amino acid that is widely used in food and medicine. Although in previous studies, a microbial fermentation method for L-theanine without the addition of ethylamine has been developed, the conversion rate of this process needs to be further improved. In this study, we constructed a de novo synthesis pathway of L-theanine with glucose as the substrate. First, an in vitro transformation pathway containing ω-transaminase (TA) and γ-glutamylmethylamide synthetase (GMAS) was designed, optimized, and introduced into the chassis strain Escherichia coli K12 W3110 to achieve de novo synthesis of L-theanine. To improve the synthesis efficiency through metabolic engineering, we increased the copies of the GMAS gene gams and the TA gene spuC and enhanced the expression of the aldehyde dehydrogenase gene eutE to provide sufficient acetaldehyde substrate, knocked out the lactate dehydrogenase gene ldhA and the pyruvate formate lyase gene pflB to block bypass metabolism, and introduced the alanine dehydrogenase gene alD to recycle alanine. Furthermore, we over-expressed the phosphoenolpyruvate carboxylase gene ppc to enhance the carbon flux of the TCA cycle, knocked out the succinyl-CoA synthase gene sucCD to reduce the loss of downstream flux of TCA, and integrated the glutamate dehydrogenase gene gdh to enhance the supply of L-glutamate. Finally, the polyphosphate kinase gene ppk was introduced to the ATP cycle, which enhanced the energy supply in L-theanine production. The recombinant strain Tea11 produced 22.60 g/L L-theanine in a 5 L fermenter in 28 h, with a conversion rate of 41.71%. This synthetic pathway in this study balanced the relationship between the supply of ethylamine and the production of theanine, providing a new idea for metabolic engineering of microorganisms to produce L-theanine.
Glutamates/biosynthesis*
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Metabolic Engineering/methods*
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Escherichia coli/genetics*
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Fermentation
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Transaminases/metabolism*
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Amide Synthases/metabolism*
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Glucose/metabolism*


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