Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been...Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been demonstrated to be a regulator of inflammation.Whether MST4 participates in the macrophage-dependent inflammation of ITP remains elusive.The expression and function of MST4 in macrophages of ITP patients and THP-1 cells,and of a macrophage-specific Mst4−/−(Mst4ΔM/ΔM)ITP mouse model were determined.Macrophage phagocytic assays,RNA sequencing(RNA-seq)analysis,immunofluorescence analysis,coimmunoprecipitation(co-IP),mass spectrometry(MS),bioinformatics analysis,and phosphoproteomics analysis were performed to reveal the underlying mechanisms.The expression levels of the MST4 gene were elevated in the expanded M1-like macrophages of ITP patients,and this elevated expression of MST4 was restored to basal levels in patients with remission after high-dose dexamethasone treatment.The expression of the MST4 gene was significantly elevated in THP-1-derived M1 macrophages.Silencing of MST4 decreased the expression of M1 macrophage markers and cytokines,and impaired phagocytosis,which could be increased by overexpression of MST4.In a passive ITP mouse model,macrophage-specific depletion of Mst4 reduced the numbers of M1 macrophages in the spleen and peritoneal lavage fluid,attenuated the expression of M1 cytokines,and promoted the predominance of FcγRIIb in splenic macrophages,which resulted in amelioration of thrombocytopenia.Downregulation of MST4 directly inhibited STAT1 phosphorylation,which is essential for M1 polarization of macrophages.Our study elucidates a critical role for MST4 kinase in the pathology of ITP and identifies MST4 kinase as a potential therapeutic target for refractory ITP.展开更多
人程序性细胞死亡因子10(programmed cell death 10,PDCD10)最初被称为TFAR15(TF-1 cell apoptosis related gene 15),是在1999年运用cDNA-RDA技术首先克隆得到的一个新基因,早期研究提示与凋亡抑制功能相关.近期国外多项研究证明,PDCD1...人程序性细胞死亡因子10(programmed cell death 10,PDCD10)最初被称为TFAR15(TF-1 cell apoptosis related gene 15),是在1999年运用cDNA-RDA技术首先克隆得到的一个新基因,早期研究提示与凋亡抑制功能相关.近期国外多项研究证明,PDCD10基因的缺失和突变与颅内海绵状血管瘤(cerebral cavernous malformations,CCM)的发生密切相关,CCM的第三个致病基因CCM3即为PDCD10.此外,其他研究表明,PDCD10受到严格的表达调控,在多种肿瘤组织中表达明显上调,提示可能在肿瘤的信号转导通路中起重要作用.最近通过对PDCD10相互作用蛋白的分析和研究,首次证实了PDCD10可以和Ste20激酶家族成员MST4相互作用,增强其激酶活性,并进而通过对ERK-MAPK通路的调控,促进细胞增殖和转化.以上研究证明了PDCD10的多种生物学效应,并提示其在血管生成和肿瘤中发挥重要作用.展开更多
Grain size,which encompasses grain length,width,and thickness,is a critical determinant of both grain weight and quality in rice.Despite the extensive regulatory networks known to determine grain length and width,the ...Grain size,which encompasses grain length,width,and thickness,is a critical determinant of both grain weight and quality in rice.Despite the extensive regulatory networks known to determine grain length and width,the pathway(s)that regulate grain thickness remain to be clarified.Here,we present the mapbased cloning and characterization of qGT3,a major quantitative trait locus for grain thickness in rice that encodes the MADS-domain transcription factor OsMADS1.Our findings demonstrate that OsMADS1 regulates grain thickness by affecting sugar delivery during grain filling,and we show that OsMADS1 modulates expression of the downstream monosaccharide transporter gene MST4.A natural variant leads to alternative splicing and thus to a truncated OsMADS1 protein with attenuated transcriptional repressor activity.The truncated OsMADS1 protein results in increased expression of MST4,leading to enhanced loading of monosaccharides into the developing endosperm and thereby increasing grain thickness and improving grain quality.In addition,our results reveal that NF-YB1 and NF-YC12 interact directly with OsMADS1,acting as cofactors to enhance its transcriptional activity toward MST4.Collectively,these findings reveal a novel molecular mechanism underlying grain thickness regulation that is controlled by the OsMADS1–NF-YB1–YC12 complex and has great potential for synergistic improvement of grain yield and quality in rice.展开更多
基金supported by grants from the National Natural Science Foundation of China(82370130,81870098,82300146)the Program of the Shanghai Academic/Technology Researcher Leader(20XD1401000)+2 种基金the Shanghai Engineering Research Center of Tumor Multi-Target Gene Diagnosis(20DZ2254300)the Key Subject Construction Program of the Shanghai Health Administrative Authority(ZK2019B30)the Science and Technology Commission of the Shanghai Municipality(21ZR1459000).
文摘Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been demonstrated to be a regulator of inflammation.Whether MST4 participates in the macrophage-dependent inflammation of ITP remains elusive.The expression and function of MST4 in macrophages of ITP patients and THP-1 cells,and of a macrophage-specific Mst4−/−(Mst4ΔM/ΔM)ITP mouse model were determined.Macrophage phagocytic assays,RNA sequencing(RNA-seq)analysis,immunofluorescence analysis,coimmunoprecipitation(co-IP),mass spectrometry(MS),bioinformatics analysis,and phosphoproteomics analysis were performed to reveal the underlying mechanisms.The expression levels of the MST4 gene were elevated in the expanded M1-like macrophages of ITP patients,and this elevated expression of MST4 was restored to basal levels in patients with remission after high-dose dexamethasone treatment.The expression of the MST4 gene was significantly elevated in THP-1-derived M1 macrophages.Silencing of MST4 decreased the expression of M1 macrophage markers and cytokines,and impaired phagocytosis,which could be increased by overexpression of MST4.In a passive ITP mouse model,macrophage-specific depletion of Mst4 reduced the numbers of M1 macrophages in the spleen and peritoneal lavage fluid,attenuated the expression of M1 cytokines,and promoted the predominance of FcγRIIb in splenic macrophages,which resulted in amelioration of thrombocytopenia.Downregulation of MST4 directly inhibited STAT1 phosphorylation,which is essential for M1 polarization of macrophages.Our study elucidates a critical role for MST4 kinase in the pathology of ITP and identifies MST4 kinase as a potential therapeutic target for refractory ITP.
基金supported by grants from the Ministry of Science and Technology(2022YFD1200100 and 2021YFF1000200)the National Natural Science Foundation of China(U21A20211 and 31821005)+1 种基金the Hubei Science and Technology(2024BBA005),the AgroST Project(NK20220501)the China Agricultural Research System(CARS-01-01).
文摘Grain size,which encompasses grain length,width,and thickness,is a critical determinant of both grain weight and quality in rice.Despite the extensive regulatory networks known to determine grain length and width,the pathway(s)that regulate grain thickness remain to be clarified.Here,we present the mapbased cloning and characterization of qGT3,a major quantitative trait locus for grain thickness in rice that encodes the MADS-domain transcription factor OsMADS1.Our findings demonstrate that OsMADS1 regulates grain thickness by affecting sugar delivery during grain filling,and we show that OsMADS1 modulates expression of the downstream monosaccharide transporter gene MST4.A natural variant leads to alternative splicing and thus to a truncated OsMADS1 protein with attenuated transcriptional repressor activity.The truncated OsMADS1 protein results in increased expression of MST4,leading to enhanced loading of monosaccharides into the developing endosperm and thereby increasing grain thickness and improving grain quality.In addition,our results reveal that NF-YB1 and NF-YC12 interact directly with OsMADS1,acting as cofactors to enhance its transcriptional activity toward MST4.Collectively,these findings reveal a novel molecular mechanism underlying grain thickness regulation that is controlled by the OsMADS1–NF-YB1–YC12 complex and has great potential for synergistic improvement of grain yield and quality in rice.
