1.Research progress on carrier-free and carrier-supported supramolecular nanosystems of traditional Chinese medicine anti-tumor star molecules
Zi-ye ZANG ; Yao-zhi ZHANG ; Yi-hang ZHAO ; Xin-ru TAN ; Ji-chang WEI ; An-qi XU ; Hong-fei DUAN ; Hong-yan ZHANG ; Peng-long WANG ; Xue-mei HUANG ; Hai-min LEI
Acta Pharmaceutica Sinica 2024;59(4):908-917
Anti-tumor traditional Chinese medicine has a long history of clinic application, in which the star molecules have always been the hotspot of modern drug research, but they are limited by the solubility, stability, targeting, bioactivity or toxicity of the monomer components of traditional Chinese medicine anti-tumor star molecules and other pharmacokinetic problems, which hinders the traditional Chinese medicine anti-tumor star molecules for further clinical translation and application. Currently, the nanosystems prepared by supramolecular technologies such as molecular self-assembly and nanomaterial encapsulation have broader application prospects in improving the anti-tumor effect of active components of traditional Chinese medicine, which has attracted extensive attention from scholars at home and abroad. In this paper, we systematically review the research progress in preparation of supramolecular nano-systems from anti-tumor star molecule of traditional Chinese medicine, and summarize the two major categories and ten small classes of carrier-free and carrier-based supramolecular nanosystems and their research cases, and the future development direction is put forward. The purpose of this paper is to provide reference for the research and clinical transformation of using supramolecular technology to improve the clinical application of anti-tumor star molecule of traditional Chinese medicine.
2.Colorectal adenocarcinoma with enteroblastic differentiation: a clinicopathological analysis of eight cases
Qi WANG ; Yan ZHANG ; Cong TAN ; Shujuan NI ; Dan HUANG ; Bin CHANG ; Weiqi SHENG ; Lei WANG
Chinese Journal of Pathology 2024;53(4):370-376
Objective:To investigate the clinicopathological features of colorectal adenocarcinoma with enteroblastic differentiation (CAED).Methods:Eight cases of CAED diagnosed at the Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China from January 2017 to August 2023 were collected. The histopathological, immunohistochemical, molecular and prognostic features of 8 CAED cases were analyzed. The relevant studies were also reviewed.Results:Among the eight patients, there were six males and two females, with an average age of 58 years (range: 29-77 years, median age: 61.5 years). Preoperative serum alpha-fetoprotein levels were elevated in five patients (14.0-286.6 μg/L). Four tumors were located in the colon, and four tumors in the rectum. Two patients were clinically staged as advanced stage (stage Ⅳ), and distant metastasis occurred at the initial diagnosis (one case had liver metastasis, and the other had lung, bone and multiple lymph nodes metastases). Six patients were clinically staged as locally-advanced stage (Stage Ⅱ-Ⅲ). Three of them developed distant metastases after surgery (one case had liver metastasis, one case had lung metastasis, and one case had peritoneal metastasis). Additionally, two patients died at 9 months and 24 months after surgery, respectively. The tumors were composed of various proportions of adenocarcinoma components with enteroblastic differentiation (30%-100%) and classical tubular adenocarcinoma components. The component with enteroblastic differentiation exhibited morphology similar to embryonic intestinal epithelium: cuboidal or columnar tumor cells arranged in tubular, papillary, cribriform, or solid nest patterns, with clear cytoplasm. Immunohistochemical studies showed that tumor cells expressed at least one oncofetal protein (SALL4, Glypican-3, and AFP). In addition, focal squamous differentiation was observed in 3 cases (3/8). Compared to the primary tumor, both CAED and squamous differentiation components were increased in the metastatic tumors. Based on the sequencing results of KRAS, NRAS and BRAF of the primary and/or metastatic tumors, 5 cases were wild-type, while KRAS exon 2 (G13D) mutations were identified in 2 cases.Conclusions:CAED is a rare colorectal malignancy with a dismal prognosis. Accurate pathological diagnosis is prognostically valuable. The histological features of enteroblastic differentiation, elevated serum AFP levels, and the expression of oncofetal proteins play an important role in the tumor diagnosis.
3.Analysis of β-thalassemia gene testing results in western region of Guangxi Zhuang Autonomous Region
Xuejuan NONG ; Yu HUANG ; Jihong JIA ; Ming LEI ; Guidan XU ; Wujun WEI ; Zhengyi CHANG ; Liqiu XIE ; Juhua LIANG ; Chunfang WANG
Chinese Journal of Endemiology 2024;43(2):104-112
Objective:To analyze the positive detection rate, main genotypes of β-thalassemia in western region of Guangxi Zhuang Autonomous Region (referred to as Guangxi).Methods:Retrospective analysis of 26 189 individuals who underwent gene testing for thalassemia at the Affiliated Hospital of Youjiang Medical University for Nationalities from January 2013 to December 2019. Using the crossing breakpoint PCR (Gap-PCR) and reverse dot blot (RDB) techniques to detect Chinese common type of 7 kinds of α-thalassemia and 17 kinds of β-thalassemia genotypes, high-throughput sequencing(Sanger) was performed for suspected rare β-thalassemia. Gap-PCR was used for suspected deletion β-thalassemia types.Results:β-thalassemia was diagnosed in 4 495 (17.16%) of 26 189 samples. A total of 6 177 alleles of 20 types of β-thalassemia were detected, mainly CD17 (2 712 cases, 43.90%) and CD41-42 (2 240 cases, 36.26%), including 7 rare alleles: Gγ +( Aγδβ) 0, SEA-HPFH, Hb New York, Hb G-Taipei, Hb Hezhou, Hb G-Coushatta and IVS-Ⅱ-81. There were 3 903 case (86.83%) heterozygous, 273 case (6.07%) double heterozygous, and 319 case (7.10%) homozygous among 4 495 β-thalassaemia subjects. A total of 48 genotypes were detected. The two most common genotypes were CD17/β N (1 890 cases, 42.05%) and CD41-42/β N (1 212 cases, 26.96%), accounted for 69.01% (3 102/4 495). Seven rare genotypes were detected: Gγ +( Aγδβ) 0/β N in 3 cases, Hb New York/β N in 3 cases, Hb G-Taipei/β N in 2 cases, SEA-HPFH/β N, Hb Hezhou/β N, Hb G-Coushatta/β N and IVS-Ⅱ-81/β N in 1 case each. A total of 1 041 cases (3.97%, 1 041/26 189) of 116 types of αβ-thalassemia were detected, mainly -- SEA/αα composite CD17/β N (144 cases, 13.83%), followed by -α 3.7/αα composite CD17/β N (112 cases, 10.76%). Conclusions:Western region of Guangxi is a high prevalence area of β-thalassemia, CD17/β N and CD41-42/β N are the main genotypes. The variation spectrum of β-thalassemia is complex and diverse, with rich genotype.
4.Genetic Mutation Profile and Risk Stratification of Cytogenetically Normal Acute Myeloid Leukemia with CEBPA-bZIP Mutations Based on Multi-Gene Sequencing
Lei-Ming CAO ; Ming-Yue LIAO ; Ya-Lan ZHOU ; Hao JIANG ; Qian JIANG ; Ying-Jun CHANG ; Lan-Ping XU ; Xiao-Hui ZHANG ; Xiao-Jun HUANG ; Guo-Rui RUAN
Journal of Experimental Hematology 2024;32(6):1631-1637
Objective:To evaluate the gene mutation profile and prognostic significance of adult cytogenetically normal acute myeloid leukemia (CN-AML) with CEBPA-bZIP mutation. Methods:Targeted sequencing was implemented on the diagnostic bone marrow DNA samples of 141 adult CN-AML subjects with CEBPA-bZIP mutation. The nomogram model for leukemia-free survival (LFS) rate was generated by combining genetic abnormalities and clinical data. Risk stratification was conducted based on prognostic variables and the effect of risk-adjusted consolidation therapy was investigated by Kaplan-Meier method. Results:Four variables were finally included in our nomogram model after multivariate Cox analysis,and an equation for risk score calculation was obtained,risk score=1.3002×white blood cell (WBC) (≥18.77×109/L)+1.4065×CSF3R mutation positive+2.6489×KMT2A mutation positive+1.0128×DNA methylation-related genes mutation positive. According to the nomogram model,patients were further divided into low-risk group (score=0,n=46) and high-risk group (score>0,n=95). Prognostic analysis showed that the 5-year LFS rate,5-year overall survival (OS) rate,and 5-year cumulative incidence of relapse (CIR) of patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the high-risk group were 93.5%,97.1%,and 3.5%,while those in patients who received maintenance chemotherapy were 32.9%,70.5%,and 63.4%,respectively. The differences were statistically significant (all P<0.05). Allo-HSCT could significantly improve the prognosis of patients in high-risk group. However,no corresponding benefit was observed in the low-risk group. Conclusion:Adult CN-AML with CEBPA-bZIP mutation has a complex co-mutation pattern. The nomogram model based on mutations of CFS3R,KMT2A and DNA methylation-related genes together with WBC count can further divide this subset of patients into a relatively low-risk group and a relatively high-risk group. For individuals in the high-risk group,allo-HSCT is proposed as post-remission therapy. The above data will benefit the prognosis estimation and treatment decision for adult CN-AML with CEBPA-bZIP mutation.
5.Study of lncRNA-miRNA-mRNA ceRNA regulatory network mediated by serum exosomes in coronary heart disease and prediction and experimental validation of potential target herbal medicines
Lu MA ; Lei YANG ; Huang DING ; Wan-Yu LI ; Wei TAN ; Yan-Ling LI ; Yan-Yan ZHANG ; Xiao-Dan LIU ; Zhao-Wen ZENG ; Chang-Qing DENG ; Wei ZHANG
Chinese Pharmacological Bulletin 2024;40(6):1153-1164
Aim To analyze serum exosome sequencing data from patients with coronary heart disease(CHD)and normal subjects by using bioinformatics-related methods to construct a competitive endogenous ln-cRNA-miRNA-mRNA(ceRNA)regulatory network,to mine the predicted potential Chinese medicines,and to perform preliminary validation of the biological processes and core Chinese medicines involved in the ceRNA network.Methods We used exoRbase data-base to obtain the expression matrix of differential genes,combined with the raw letter method to con-struct the ceRNA network,and performed GO analysis and KEGG analysis on the differential mRNAs in the network,and used COREMINE database to predict the biological processes and core target genes involved in the ceRNA network,and to screen the herbal medi-cines with potential therapeutic effects;AVECs oxida-tive damage cell model was constructed in vitro,and the cytoskeleton,tube-forming function,cell prolifera-tion,LDH leakage rate,ROS level and p-AKT,AKT,p-PI3K and AKT protein expression were examined to verify the action pathways and targets of the core Chi-nese medicine Salvia miltiorrhiza for the treatment of coronary heart disease.Results Compared with nor-mal subjects,395 mRNAs,80 miRNAs,60 lncRNA differential genes,and 80 miRNAs were predicted in serum exosomes of coronary heart disease,and the constructed ceRNA sub-network,mainly consisted of 21 lncRNAs,80 miRNAs,and 82 mRNAs;AKT1,VEGFA,IL1B and other genes in the network.The abnormally expressed mRNAs were involved in biologi-cal processes such as oxidative stress and signaling pathways such as PI3 K/Akt,and Dan Shen,Chuanx-iong and Panax notoginseng were most closely related to exosome-mediated biological processes and core genes in coronary heart disease.The active ingredients of tanshinone ⅡA,the core Chinese medicine,could pro-mote vascular endothelial cell proliferation,tube for-mation,skeleton formation and repair,reduce LDH leakage rate and ROS level,and promote the expres-sion of p-AKT and p-PI3K protein.Conclusion There is a complex ceRNA regulatory network trans-duction in coronary artery disease serum exosomes,and traditional Chinese medicine can be used to treat CHD through multi-target intervention,and Dan Shen,Chuanxiong and Panax notoginseng are expected to be candidate sources of traditional Chinese medicine,a-mong which the active ingredient of Dan Shen,tanshi-none ⅡA,activates PI3 K/Akt signaling pathway to play a protective role against oxidative stress-injured cells,and treats CHD.
6.TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children
Xi MING ; Liqun WU ; Ziwei WANG ; Bo WANG ; Jialin ZHENG ; Jingwei HUO ; Mei HAN ; Xiaochun FENG ; Baoqing ZHANG ; Xia ZHAO ; Mengqing WANG ; Zheng XUE ; Ke CHANG ; Youpeng WANG ; Yanhong QIN ; Bin YUAN ; Hua CHEN ; Lining WANG ; Xianqing REN ; Hua XU ; Liping SUN ; Zhenqi WU ; Yun ZHAO ; Xinmin LI ; Min LI ; Jian CHEN ; Junhong WANG ; Yonghong JIANG ; Yongbin YAN ; Hengmiao GAO ; Hongmin FU ; Yongkun HUANG ; Jinghui YANG ; Zhu CHEN ; Lei XIONG
Journal of Nanjing University of Traditional Chinese Medicine 2024;40(7):722-732
Following the principles of evidence-based medicine,in accordance with the structure and drafting rules of standardized documents,based on literature research,according to the characteristics of chronic cough in children and issues that need to form a consensus,the TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children was formulated based on the Delphi method,expert discussion meetings,and public solicitation of opinions.The guideline includes scope of application,terms and definitions,eti-ology and diagnosis,auxiliary examination,treatment,prevention and care.The aim is to clarify the optimal treatment plan of Chinese medicine in the diagnosis and treatment of this disease,and to provide guidance for improving the clinical diagnosis and treatment of chronic cough in children with Chinese medicine.
7.Multicenter retrospect analysis of early clinical features and analysis of risk factors on prognosis of elderly patients with severe burns
Qimin MA ; Wenbin TANG ; Xiaojian LI ; Fei CHANG ; Xi YIN ; Zhaohong CHEN ; Guohua WU ; Chengde XIA ; Xiaoliang LI ; Deyun WANG ; Zhigang CHU ; Yi ZHANG ; Lei WANG ; Choulang WU ; Yalin TONG ; Pei CUI ; Guanghua GUO ; Zhihao ZHU ; Shengyu HUANG ; Liu CHANG ; Rui LIU ; Yongji LIU ; Yusong WANG ; Xiaobin LIU ; Tuo SHEN ; Feng ZHU
Chinese Journal of Burns 2024;40(3):249-257
Objective:To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis.Methods:This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924 th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results:Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m 2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions:The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.
8.EPCs-exos combined with tanshinone Ⅱ_A protect vascular endothelium cells from oxidative damage via PI3K/Akt pathway.
Lu MA ; Lei YANG ; Chang-Qing DENG ; Wei ZHANG ; Huang DING ; Xiao-Dan LIU ; Wan-Yu LI ; Jiang WEN ; Wei TAN ; Yan-Ling LI ; Yan-Yan ZHANG ; Xin-Ying FU ; Lin-Quan LIU ; Cai-Xia LIU ; Zhao-Wen ZENG
China Journal of Chinese Materia Medica 2023;48(23):6423-6433
This study aims to investigate the molecular mechanism of tanshinone Ⅱ_(A )(TaⅡ_A) combined with endothelial progenitor cells-derived exosomes(EPCs-exos) in protecting the aortic vascular endothelial cells(AVECs) from oxidative damage via the phosphatidylinositol 3 kinase(PI3K)/protein kinase B(Akt) pathway. The AVECs induced by 1-palmitoyl-2-(5'-oxovaleroyl)-sn-glycero-3-phosphocholine(POVPC) were randomly divided into model, TaⅡ_A, EPCs-exos, and TaⅡ_A+EPCs-exos groups, and the normal cells were taken as the control group. The cell counting kit-8(CCK-8) was used to examine the cell proliferation. The lactate dehydrogenase(LDH) cytotoxicity assay kit, Matrigel assay, DCFH-DA fluorescent probe, and laser confocal microscopy were employed to examine the LDH release, tube-forming ability, cellular reactive oxygen species(ROS) level, and endothelial cell skeleton morphology, respectively. The enzyme-linked immunosorbent assay was employed to measure the expression of interleukin(IL)-1β, IL-6, and tumor necrosis factor(TNF)-α. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to determine the mRNA and protein levels, respectively, of PI3K and Akt. Compared with the control group, the model group showed decreased cell proliferation and tube-forming ability, increased LDH release, elevated ROS level, obvious cytoskeletal disruption, increased expression of IL-1β, IL-6, and TNF-α, and down-regulated mRNA and protein levels of PI3K and Akt. Compared with the model group, TaⅡ_A or EPCs-exos alone increased the cell proliferation and tube-forming ability, reduced LDH release, lowered the ROS level, repaired the damaged skeleton, decreased the expression of IL-1β, IL-6, and TNF-α, and up-regulated the mRNA and protein levels of PI3K and Akt. TaⅡ_A+EPCs-exos outperformed TaⅡ_A or EPCs-exos alone in regulating the above indexes. The results demonstrated that TaⅡ_A and EPCs-exos exerted a protective effect on POVPC-induced AVECs by activating the PI3K/Akt pathway, and the combination of the two had stronger therapeutic effect.
Proto-Oncogene Proteins c-akt/metabolism*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Signal Transduction
;
Reactive Oxygen Species/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Interleukin-6/metabolism*
;
Endothelium, Vascular
;
Oxidative Stress
;
Endothelial Progenitor Cells
;
RNA, Messenger/metabolism*
;
Abietanes
9.Developing a diagnostic model for predicting prostate cancer: a retrospective study based on Chinese multicenter clinical data.
Chang-Ming WANG ; Lei YUAN ; Xue-Han LIU ; Shu-Qiu CHEN ; Hai-Feng WANG ; Qi-Fei DONG ; Bin ZHANG ; Ming-Shuo HUANG ; Zhi-Yong ZHANG ; Jun XIAO ; Tao TAO
Asian Journal of Andrology 2023;26(1):34-40
The overdiagnosis of prostate cancer (PCa) caused by nonspecific elevation serum prostate-specific antigen (PSA) and the overtreatment of indolent PCa have become a global problem that needs to be solved urgently. We aimed to construct a prediction model and provide a risk stratification system to reduce unnecessary biopsies. In this retrospective study, clinical data of 1807 patients from three Chinese hospitals were used. The final model was built using stepwise logistic regression analysis. The apparent performance of the model was assessed by receiver operating characteristic curves, calibration plots, and decision curve analysis. Finally, a risk stratification system of clinically significant prostate cancer (csPCa) was created, and diagnosis-free survival analyses were performed. Following multivariable screening and evaluation of the diagnostic performances, a final diagnostic model comprised of the PSA density and Prostate Imaging-Reporting and Data System (PI-RADS) score was established. Model validation in the development cohort and two external cohorts showed excellent discrimination and calibration. Finally, we created a risk stratification system using risk thresholds of 0.05 and 0.60 as the cut-off values. The follow-up results indicated that the diagnosis-free survival rate for csPCa at 12 months and 24 months postoperatively was 99.7% and 99.4%, respectively, for patients with a risk threshold below 0.05 after the initial negative prostate biopsy, which was significantly better than patients with higher risk. Our diagnostic model and risk stratification system can achieve a personalized risk calculation of csPCa. It provides a standardized tool for Chinese patients and physicians when considering the necessity of prostate biopsy.
10.METTL14 is a chromatin regulator independent of its RNA N6-methyladenosine methyltransferase activity.
Xiaoyang DOU ; Lulu HUANG ; Yu XIAO ; Chang LIU ; Yini LI ; Xinning ZHANG ; Lishan YU ; Ran ZHAO ; Lei YANG ; Chuan CHEN ; Xianbin YU ; Boyang GAO ; Meijie QI ; Yawei GAO ; Bin SHEN ; Shuying SUN ; Chuan HE ; Jun LIU
Protein & Cell 2023;14(9):683-697
METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on stemness maintenance of mouse embryonic stem cell (mESC). While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-independent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification. Mechanistically, METTL14, but not METTL3, binds H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression. The effects of METTL14 on regulation of H3K27me3 is essential for the transition from self-renewal to differentiation of mESCs. This work reveals a regulatory mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance, and differentiation of mESCs.
Animals
;
Mice
;
Methylation
;
Chromatin
;
Histones/metabolism*
;
RNA, Messenger/genetics*
;
Methyltransferases/metabolism*
;
RNA/metabolism*

Result Analysis
Print
Save
E-mail