1
|
Guan L, Voora D, Myers R, Del Carpio-Cano F, Rao AK. RUNX1 isoforms regulate RUNX1 and target genes differentially in platelets-megakaryocytes: association with clinical cardiovascular events. J Thromb Haemost 2024:S1538-7836(24)00480-X. [PMID: 39181539 DOI: 10.1016/j.jtha.2024.07.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 08/27/2024]
Abstract
BACKGROUND Hematopoietic transcription factor RUNX1 is expressed from proximal P2 and distal P1 promoters to yield isoforms RUNX1 B and C, respectively. The roles of these isoforms in RUNX1 autoregulation and downstream gene regulation in megakaryocytes and platelets are unknown. OBJECTIVES To understand the regulation of RUNX1 and its target genes by RUNX1 isoforms. METHODS We performed studies on RUNX1 isoforms in megakaryocytic human erythroleukemia (HEL) cells and HeLa cells (lack endogenous RUNX1), in platelets from 85 healthy volunteers administered aspirin or ticagrelor, and on the association of RUNX1 target genes with acute events in 587 patients with cardiovascular disease (CVD). RESULTS In chromatin immunoprecipitation and luciferase promoter assays, RUNX1 isoforms B and C bound and regulated P1 and P2 promoters. In HeLa cells, RUNX1B decreased and RUNX1C increased P1 and P2 activities, respectively. In HEL cells, RUNX1B overexpression decreased RUNX1C and RUNX1A expression; RUNX1C increased RUNX1B and RUNX1A. RUNX1B and RUNX1C regulated target genes (MYL9, F13A1, PCTP, PDE5A, and others) differentially in HEL cells. In platelets, RUNX1B transcripts (by RNA sequencing) correlated negatively with RUNX1C and RUNX1A; RUNX1C correlated positively with RUNX1A. RUNX1B correlated positively with F13A1, PCTP, PDE5A, RAB1B, and others, and negatively with MYL9. In our previous studies, RUNX1C transcripts in whole blood were protective against acute events in CVD patients. We found that higher expression of RUNX1 targets F13A1 and RAB31 associated with acute events. CONCLUSION RUNX1 isoforms B and C autoregulate RUNX1 and regulate downstream genes in a differential manner, and this is associated with acute events in CVD.
Collapse
Affiliation(s)
- Liying Guan
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Deepak Voora
- Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Rachel Myers
- Duke Clinical Research Unit, Duke University School of Medicine, Durham, North Carolina, USA
| | - Fabiola Del Carpio-Cano
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - A Koneti Rao
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA; Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
2
|
Guan L, Voora D, Myers R, Del Carpio-Cano F, Rao AK. RUNX1 Isoforms Regulate RUNX1 and Target-Genes Differentially in Platelets-Megakaryocytes: Association with Clinical Cardiovascular Events. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599563. [PMID: 38948740 PMCID: PMC11212995 DOI: 10.1101/2024.06.18.599563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Background Hematopoietic transcription factor RUNX1 is expressed from proximal P2 and distal P1 promoter to yield isoforms RUNX1 B and C, respectively. The roles of these isoforms in RUNX1 autoregulation and downstream-gene regulation in megakaryocytes and platelets are unknown. Objectives To understand the regulation of RUNX1 and its target genes by RUNX1 isoforms. Methods We performed studies on RUNX1 isoforms in megakaryocytic HEL cells and HeLa cells (lack endogenous RUNX1), in platelets from 85 healthy volunteers administered aspirin or ticagrelor, and on the association of RUNX1 target genes with acute events in 587 patients with cardiovascular disease (CVD). Results In chromatin immunoprecipitation and luciferase promoter assays, RUNX1 isoforms B and C bound and regulated P1 and P2 promoters. In HeLa cells RUNX1B decreased and RUNX1C increased P1 and P2 activities, respectively. In HEL cells, RUNX1B overexpression decreased RUNX1C and RUNX1A expression; RUNX1C increased RUNX1B and RUNX1A. RUNX1B and RUNX1C regulated target genes (MYL9, F13A1, PCTP, PDE5A and others) differentially in HEL cells. In platelets RUNX1B transcripts (by RNAseq) correlated negatively with RUNX1C and RUNX1A; RUNX1C correlated positively with RUNX1A. RUNX1B correlated positively with F13A1, PCTP, PDE5A, RAB1B, and others, and negatively with MYL9. In our previous studies, RUNX1C transcripts in whole blood were protective against acute events in CVD patients. We found that higher expression of RUNX1 targets F13A1 and RAB31 associated with acute events. Conclusions RUNX1 isoforms B and C autoregulate RUNX1 and regulate downstream genes in a differential manner and this associates with acute events in CVD.
Collapse
Affiliation(s)
- Liying Guan
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Deepak Voora
- Department of Medicine, Duke University, Durham, NC
| | - Rachel Myers
- Duke Clinical Research Unit, Duke University School of Medicine, Durham, NC
| | - Fabiola Del Carpio-Cano
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - A. Koneti Rao
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
- Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| |
Collapse
|
3
|
Del Carpio-Cano F, Mao G, Goldfinger LE, Wurtzel J, Guan L, Alam MA, Lee K, Poncz M, Rao AK. Altered platelet-megakaryocyte endocytosis and trafficking of albumin and fibrinogen in RUNX1 haplodeficiency. Blood Adv 2024; 8:1699-1714. [PMID: 38330198 PMCID: PMC10997914 DOI: 10.1182/bloodadvances.2023011098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 01/11/2024] [Accepted: 01/29/2024] [Indexed: 02/10/2024] Open
Abstract
ABSTRACT Platelet α-granules have numerous proteins, some synthesized by megakaryocytes (MK) and others not synthesized but incorporated by endocytosis, an incompletely understood process in platelets/MK. Germ line RUNX1 haplodeficiency, referred to as familial platelet defect with predisposition to myeloid malignancies (FPDMMs), is associated with thrombocytopenia, platelet dysfunction, and granule deficiencies. In previous studies, we found that platelet albumin, fibrinogen, and immunoglobulin G (IgG) were decreased in a patient with FPDMM. We now show that platelet endocytosis of fluorescent-labeled albumin, fibrinogen, and IgG is decreased in the patient and his daughter with FPDMM. In megakaryocytic human erythroleukemia (HEL) cells, small interfering RNA RUNX1 knockdown (KD) increased uptake of these proteins over 24 hours compared with control cells, with increases in caveolin-1 and flotillin-1 (2 independent regulators of clathrin-independent endocytosis), LAMP2 (a lysosomal marker), RAB11 (a marker of recycling endosomes), and IFITM3. Caveolin-1 downregulation in RUNX1-deficient HEL cells abrogated the increased uptake of albumin, but not fibrinogen. Albumin, but not fibrinogen, partially colocalized with caveolin-1. RUNX1 KD resulted in increased colocalization of albumin with flotillin and fibrinogen with RAB11, suggesting altered trafficking of both proteins. The increased uptake of albumin and fibrinogen, as well as levels of caveolin-1, flotillin-1, LAMP2, and IFITM3, were recapitulated by short hairpin RNA RUNX1 KD in CD34+-derived MK. To our knowledge, these studies provide first evidence that platelet endocytosis of albumin and fibrinogen is impaired in some patients with RUNX1-haplodeficiency and suggest that megakaryocytes have enhanced endocytosis with defective trafficking, leading to loss of these proteins by distinct mechanisms. This study provides new insights into mechanisms governing endocytosis and α-granule deficiencies in RUNX1-haplodeficiency.
Collapse
Affiliation(s)
- Fabiola Del Carpio-Cano
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Guangfen Mao
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Lawrence E. Goldfinger
- Division of Hematology, Department of Medicine, Cardeza Foundation for Hematologic Research, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Jeremy Wurtzel
- Division of Hematology, Department of Medicine, Cardeza Foundation for Hematologic Research, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Liying Guan
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Mohammad Afaque Alam
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Kiwon Lee
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Seoul, Korea
| | - Mortimer Poncz
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - A. Koneti Rao
- Sol Sherry Thrombosis Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
- Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| |
Collapse
|
4
|
Chen H, Zhou S, Wang Y, Zhang Q, Leng L, Cao Z, Luan P, Li Y, Wang S, Li H, Cheng B. HBP1 promotes chicken preadipocyte proliferation via directly repressing SOCS3 transcription. Int J Biol Macromol 2024; 256:128414. [PMID: 38029903 DOI: 10.1016/j.ijbiomac.2023.128414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 11/13/2023] [Accepted: 11/22/2023] [Indexed: 12/01/2023]
Abstract
Preadipocyte proliferation is an essential process in adipose development. During proliferation of preadipocytes, transcription factors play crucial roles. HMG-box protein 1 (HBP1) is an important transcription factor of cellular proliferation. However, the function and underlying mechanisms of HBP1 in the proliferation of preadipocytes remain unclear. Here, we found that the expression level of HBP1 decreased first and then increased during the proliferation of chicken preadipocytes. Knockout of HBP1 could inhibit the proliferation of preadipocytes, while overexpression of HBP1 could promote the proliferation of preadipocytes. ChIP-seq data showed that HBP1 had the unique DNA binding motif in chicken preadipocytes. By integrating ChIP-Seq and RNA-Seq, we revealed a total of 3 candidate target genes of HBP1. Furthermore, the results of ChIP-qPCR, RT-qPCR, luciferase reporter assay and EMSA showed that HBP1 could inhibit the transcription of suppressor of cytokine signaling 3 (SOCS3) by binding to its promoter. Moreover, we confirmed that SOCS3 can mediate the regulation of HBP1 on the proliferation of preadipocytes through RNAi and rescue experiments. Altogether, these data demonstrated that HBP1 directly targets SOCS3 to regulate chicken preadipocyte proliferation. Our findings expand the transcriptional regulatory network of preadipocyte proliferation, and they will be helpful in formulating a molecular breeding scheme to control excessive abdominal fat deposition and to improve meat quality in chickens.
Collapse
Affiliation(s)
- Hongyan Chen
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China; College of Life Science and Agriculture Forestry, Qiqihar University, Qiqihar 161006, Heilongjiang, China
| | - Sitong Zhou
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Youdong Wang
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Qi Zhang
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Li Leng
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Zhiping Cao
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Peng Luan
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Yumao Li
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Shouzhi Wang
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China
| | - Hui Li
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China.
| | - Bohan Cheng
- Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, Heilongjiang, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, Heilongjiang, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, Heilongjiang, China.
| |
Collapse
|
5
|
Carpio-Cano FD, Mao G, Goldfinger LE, Wurtzel J, Guan L, Alam AM, Lee K, Poncz ME, Rao AK. Altered Platelet-Megakaryocyte Endocytosis and Trafficking of Albumin and Fibrinogen in RUNX1 Haplodeficiency. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.23.23297335. [PMID: 37961544 PMCID: PMC10635164 DOI: 10.1101/2023.10.23.23297335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Platelet α-granules have numerous proteins, some synthesized by megakaryocytes (MK) and others not synthesized but incorporated by endocytosis, an incompletely understood process in platelets/MK. Germline RUNX1 haplodeficiency, referred to as familial platelet defect with predisposition to myeloid malignancies (FPDMM), is associated with thrombocytopenia, platelet dysfunction and granule deficiencies. In previous studies, we found that platelet albumin, fibrinogen and IgG levels were decreased in a FPDMM patient. We now show that platelet endocytosis of fluorescent-labeled albumin, fibrinogen and IgG is decreased in the patient and his daughter with FPDMM. In megakaryocytic human erythroleukemia (HEL) cells, siRNA RUNX1 knockdown (KD) increased uptake of these proteins over 24 hours compared to control cells, with increases in caveolin-1 and flotillin-1 (two independent regulators of clathrin-independent endocytosis), LAMP2 (a lysosomal marker), RAB11 (a marker of recycling endosomes) and IFITM3. Caveolin-1 downregulation in RUNX1-deficient HEL cells abrogated the increased uptake of albumin, but not fibrinogen. Albumin, but not fibrinogen, partially colocalized with caveolin-1. RUNX1 knockdown increased colocalization of albumin with flotillin and of fibrinogen with RAB11 suggesting altered trafficking of both. The increased albumin and fibrinogen uptake and levels of caveolin-1, flotillin-1, LAMP2 and IFITM3 were recapitulated by shRNA RUNX1 knockdown in CD34 + -derived MK. These studies provide the first evidence that in RUNX1- haplodeficiency platelet endocytosis of albumin and fibrinogen is impaired and that megakaryocytes have enhanced endocytosis with defective trafficking leading to loss of these proteins by distinct mechanisms. They provide new insights into mechanisms governing endocytosis and α-granule deficiencies in RUNX1- haplodeficiency. Key points Platelet content and endocytosis of α-granule proteins, albumin, fibrinogen and IgG, are decreased in germline RUNX1 haplodeficiency. In RUNX1 -deficient HEL cells and primary MK endocytosis is enhanced with defective trafficking leading to decreased protein levels.
Collapse
|
6
|
Zhu K, Li X, Gao L, Ji M, Huang X, Zhao Y, Diao W, Fan Y, Chen X, Luo P, Shen L, Li L. Identification of Hub Genes Correlated with the Initiation and Development in Chronic Kidney Disease via Bioinformatics Analysis. Kidney Blood Press Res 2023; 48:79-91. [PMID: 36603559 PMCID: PMC9979271 DOI: 10.1159/000528870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 12/04/2022] [Indexed: 01/06/2023] Open
Abstract
INTRODUCTION Chronic kidney disease (CKD) is a major public health issue worldwide, which is characterized by irreversible loss of nephron and renal function. However, the molecular mechanism of CKD remains underexplored. METHODS This study integrated three transcriptional profile datasets to investigate the molecular mechanism of CKD. The differentially expressed genes (DEGs) between Sham control (Con) and unilateral ureteral obstruction (UUO)-operated mice were analyzed by utilizing the limma package in R. The shared DEGs were analyzed by Gene Ontology and functional enrichment. Protein-protein interactions (PPIs) were constructed by utilizing the STRING database. Hub genes were analyzed by MCODE and Cytohubba. We further validated the gene expression by using the other dataset and mouse UUO model. RESULTS A total of 315 shared DEGs between Con and UUO samples were identified. Gene function and KEGG pathway enrichment revealed that DEGs were mainly enriched in inflammatory response, immune system process, and chemokine signaling pathway. Two modules were clustered based on PPI network analysis. Module 1 contained 13 genes related to macrophage activation, migration, and chemotaxis. Ten hub genes were identified by PPI network analysis. Subsequently, the expression levels of hub genes were validated with the other dataset. Finally, these four validated hub genes were further confirmed by our UUO mice. Three validated hub genes, Gng2, Pf4, and Ccl9, showed significant response to UUO. CONCLUSION Our study reveals the coordination of genes during UUO and provides a promising gene panel for CKD treatment. GNG2 and PF4 were identified as potential targets for developing CKD drugs.
Collapse
Affiliation(s)
- Kai Zhu
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xinxin Li
- Department of Urology, Tongren Hospital of Wuhan University, Wuhan Third Hospital, Wuhan, China
| | - Likun Gao
- Department of Pathology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Mengyao Ji
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xu Huang
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yu Zhao
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Wenxiu Diao
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yanqin Fan
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xinghua Chen
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Pengcheng Luo
- Department of Urology, Tongren Hospital of Wuhan University, Wuhan Third Hospital, Wuhan, China
| | - Lei Shen
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lili Li
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| |
Collapse
|
7
|
Defective RAB31-mediated megakaryocytic early endosomal trafficking of VWF, EGFR, and M6PR in RUNX1 deficiency. Blood Adv 2022; 6:5100-5112. [PMID: 35839075 PMCID: PMC9631641 DOI: 10.1182/bloodadvances.2021006945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 06/13/2022] [Indexed: 11/20/2022] Open
Abstract
RAB31 is a RUNX1 target; regulates VWF, epidermal growth factor receptor, and mannose-6-phosphate trafficking; and is downregulated in RHD. EE and vesicle trafficking defects induced by RAB31 downregulation likely contribute to α-granule defects with RUNX1 mutation.
Transcription factor RUNX1 is a master regulator of hematopoiesis and megakaryopoiesis. RUNX1 haplodeficiency (RHD) is associated with thrombocytopenia and platelet granule deficiencies and dysfunction. Platelet profiling of our study patient with RHD showed decreased expression of RAB31, a small GTPase whose cell biology in megakaryocytes (MKs)/platelets is unknown. Platelet RAB31 messenger RNA was decreased in the index patient and in 2 additional patients with RHD. Promoter-reporter studies using phorbol 12-myristate 13-acetate–treated megakaryocytic human erythroleukemia cells revealed that RUNX1 regulates RAB31 via binding to its promoter. We investigated RUNX1 and RAB31 roles in endosomal dynamics using immunofluorescence staining for markers of early endosomes (EEs; early endosomal autoantigen 1) and late endosomes (CD63)/multivesicular bodies. Downregulation of RUNX1 or RAB31 (by small interfering RNA or CRISPR/Cas9) showed a striking enlargement of EEs, partially reversed by RAB31 reconstitution. This EE defect was observed in MKs differentiated from a patient-derived induced pluripotent stem cell line (RHD-iMKs). Studies using immunofluorescence staining showed that trafficking of 3 proteins with distinct roles (von Willebrand factor [VWF], a protein trafficked to α-granules; epidermal growth factor receptor; and mannose-6-phosphate) was impaired at the level of EE on downregulation of RAB31 or RUNX1. There was loss of plasma membrane VWF in RUNX1- and RAB31-deficient megakaryocytic human erythroleukemia cells and RHD-iMKs. These studies provide evidence that RAB31 is downregulated in RHD and regulates megakaryocytic vesicle trafficking of 3 major proteins with diverse biological roles. EE defect and impaired vesicle trafficking is a potential mechanism for the α-granule defects observed in RUNX1 deficiency.
Collapse
|
8
|
Kim D, Shin DY, Liu J, Jeong NR, Koh Y, Hong J, Huang X, Broxmeyer HE, Yoon SS. Expansion of Human Megakaryocyte-Lineage Progeny via Aryl Hydrocarbon Receptor Antagonism with CH223191. Stem Cell Rev Rep 2022; 18:2982-2994. [PMID: 35687264 DOI: 10.1007/s12015-022-10386-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2022] [Indexed: 11/26/2022]
Abstract
Aryl hydrocarbon receptor (AhR) antagonism is known to expand human hematopoietic stem cells (HSCs). However, its regulatory effect on the lineage-skewed differentiation of HSCs has not been sufficiently studied. Here, we investigate the effect of the AhR-selective antagonist CH223191 on the regulation of HSC differentiation. Consistent with the well-known effects of AhR antagonists, CH223191 treatment increase phenotypic HSCs (Lin-CD34 + CD38-CD90 + CD45RA-) and preserves their functionality. On the other hand, CH223191 leads to an overall expansion of megakaryocyte (MK)-lineage populations, such as MK progenitors (MKps, CD34 + CD41 +), immature MKs (CD41 + CD42b-), and mature MKs (CD41 + CD42b +), and it also activates MK/platelet-associated signaling pathways. Furthermore, CH223191 expands MKps, mature MKs, and p-selectin (CD62p)-positive platelet-like particles in immune thrombocytopenia (ITP) patient bone marrow (BM). These results highlight the numerical expansion of human MK-lineage progeny through AhR antagonism with CH223191. This approach using CH2231291 may be applicable in the development of auxiliary treatment regimens for patients with abnormal thrombopoiesis.
Collapse
Affiliation(s)
- Dongchan Kim
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Dong-Yeop Shin
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.
- Department of Internal Medicine, College of Medicine, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Jun Liu
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Na-Rae Jeong
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Youngil Koh
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Internal Medicine, College of Medicine, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Junshik Hong
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Internal Medicine, College of Medicine, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Xinxin Huang
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Hal E Broxmeyer
- Department of Microbiology and Immunology, Indiana University School of Medicine (IUSM), Indianapolis, IN, USA
| | - Sung-Soo Yoon
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Center for Medical Innovation of Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.
- Department of Internal Medicine, College of Medicine, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| |
Collapse
|
9
|
Noh JY. Megakaryopoiesis and Platelet Biology: Roles of Transcription Factors and Emerging Clinical Implications. Int J Mol Sci 2021; 22:ijms22179615. [PMID: 34502524 PMCID: PMC8431765 DOI: 10.3390/ijms22179615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 12/13/2022] Open
Abstract
Platelets play a critical role in hemostasis and thrombus formation. Platelets are small, anucleate, and short-lived blood cells that are produced by the large, polyploid, and hematopoietic stem cell (HSC)-derived megakaryocytes in bone marrow. Approximately 3000 platelets are released from one megakaryocyte, and thus, it is important to understand the physiologically relevant mechanism of development of mature megakaryocytes. Many genes, including several key transcription factors, have been shown to be crucial for platelet biogenesis. Mutations in these genes can perturb megakaryopoiesis or thrombopoiesis, resulting in thrombocytopenia. Metabolic changes owing to inflammation, ageing, or diseases such as cancer, in which platelets play crucial roles in disease development, can also affect platelet biogenesis. In this review, I describe the characteristics of platelets and megakaryocytes in terms of their differentiation processes. The role of several critical transcription factors have been discussed to better understand the changes in platelet biogenesis that occur during disease or ageing.
Collapse
Affiliation(s)
- Ji-Yoon Noh
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Korea
| |
Collapse
|
10
|
Wang C, Gong Y, Wei A, Huang T, Hou S, Du J, Li Z, Wang J, Liu B, Lan Y. Adult-repopulating lymphoid potential of yolk sac blood vessels is not confined to arterial endothelial cells. SCIENCE CHINA-LIFE SCIENCES 2021; 64:2073-2087. [PMID: 34181164 DOI: 10.1007/s11427-021-1935-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 02/22/2021] [Indexed: 10/21/2022]
Abstract
During embryogenesis, hematopoietic stem progenitor cells (HSPCs) are believed to be derived from hemogenic endothelial cells (HECs). Moreover, arterial feature is proposed to be a prerequisite for HECs to generate HSPCs with lymphoid potential. Although the molecular basis of hematopoietic stem cell-competent HECs has been delicately elucidated within the embryo proper, the functional and molecular characteristics of HECs in the extraembryonic yolk sac (YS) remain largely unresolved. In this study, we initially identified six molecularly different endothelial populations in the midgestational YS through integrated analysis of several single-cell RNA sequencing (scRNA-seq) datasets and validated the arterial vasculature distribution of Gja5+ ECs using a Gja5-EGFP reporter mouse model. Further, we explored the hemogenic potential of different EC populations based on their Gja5-EGFP and CD44 expression levels. The hemogenic potential was ubiquitously detected in spatiotemporally different vascular beds on embryonic days (E)8.5-E9.5 and gradually concentrated in CD44-positive ECs from E10.0. Unexpectedly, B-lymphoid potential was detected in the YS ECs as early as E8.5 regardless of their arterial features. Furthermore, the capacity for generating hematopoietic progenitors with in vivo lymphoid potential was found in nonarterial as well as arterial YS ECs on E10.0-E10.5. Importantly, the distinct identities of E10.0-E10.5 HECs between YS and intraembryonic caudal region were revealed by further scRNA-seq analysis. Cumulatively, these findings extend our knowledge regarding the hemogenic potential of ECs from anatomically and molecularly different vascular beds, providing a theoretical basis for better understanding the sources of HSPCs during mammalian development.
Collapse
Affiliation(s)
- Chaojie Wang
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou, 510632, China
| | - Yandong Gong
- State Key Laboratory of Experimental Hematology, Institute of Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100071, China
| | - Anbang Wei
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, 100850, China
| | - Tao Huang
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, 100850, China
| | - Siyuan Hou
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou, 510632, China.,Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Junjie Du
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, 100850, China
| | - Zongcheng Li
- State Key Laboratory of Experimental Hematology, Institute of Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100071, China
| | - Junliang Wang
- Department of radiotherapy, Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100071, China
| | - Bing Liu
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou, 510632, China. .,State Key Laboratory of Experimental Hematology, Institute of Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100071, China.
| | - Yu Lan
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou, 510632, China.
| |
Collapse
|
11
|
Reduced CXCL4/PF4 expression as a driver of increased human hematopoietic stem and progenitor cell proliferation in polycythemia vera. Blood Cancer J 2021; 11:31. [PMID: 33574218 PMCID: PMC7878875 DOI: 10.1038/s41408-021-00423-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/05/2021] [Accepted: 01/20/2021] [Indexed: 01/11/2023] Open
|
12
|
Germline mutations in the transcription factor IKZF5 cause thrombocytopenia. Blood 2020; 134:2070-2081. [PMID: 31217188 DOI: 10.1182/blood.2019000782] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/10/2019] [Indexed: 01/09/2023] Open
Abstract
To identify novel causes of hereditary thrombocytopenia, we performed a genetic association analysis of whole-genome sequencing data from 13 037 individuals enrolled in the National Institute for Health Research (NIHR) BioResource, including 233 cases with isolated thrombocytopenia. We found an association between rare variants in the transcription factor-encoding gene IKZF5 and thrombocytopenia. We report 5 causal missense variants in or near IKZF5 zinc fingers, of which 2 occurred de novo and 3 co-segregated in 3 pedigrees. A canonical DNA-zinc finger binding model predicts that 3 of the variants alter DNA recognition. Expression studies showed that chromatin binding was disrupted in mutant compared with wild-type IKZF5, and electron microscopy revealed a reduced quantity of α granules in normally sized platelets. Proplatelet formation was reduced in megakaryocytes from 7 cases relative to 6 controls. Comparison of RNA-sequencing data from platelets, monocytes, neutrophils, and CD4+ T cells from 3 cases and 14 healthy controls showed 1194 differentially expressed genes in platelets but only 4 differentially expressed genes in each of the other blood cell types. In conclusion, IKZF5 is a novel transcriptional regulator of megakaryopoiesis and the eighth transcription factor associated with dominant thrombocytopenia in humans.
Collapse
|
13
|
Galera P, Dulau-Florea A, Calvo KR. Inherited thrombocytopenia and platelet disorders with germline predisposition to myeloid neoplasia. Int J Lab Hematol 2019; 41 Suppl 1:131-141. [PMID: 31069978 DOI: 10.1111/ijlh.12999] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/07/2019] [Accepted: 02/10/2019] [Indexed: 12/21/2022]
Abstract
Advances in molecular genetic sequencing techniques have contributed to the elucidation of previously unknown germline mutations responsible for inherited thrombocytopenia (IT). Regardless of age of presentation and severity of symptoms related to thrombocytopenia and/or platelet dysfunction, a subset of patients with IT are at increased risk of developing myeloid neoplasms during their life time, particularly those with germline autosomal dominant mutations in RUNX1, ANKRD26, and ETV6. Patients may present with isolated thrombocytopenia and megakaryocytic dysmorphia or atypia on baseline bone marrow evaluation, without constituting myelodysplasia (MDS). Bone marrow features may overlap with idiopathic thrombocytopenic purpura (ITP) or sporadic MDS leading to misdiagnosis. Progression to myelodysplastic syndrome/ acute myeloid leukemia (MDS/AML) may be accompanied by progressive bi- or pancytopenia, multilineage dysplasia, increased blasts, cytogenetic abnormalities, acquisition of bi-allelic mutations in the underlying gene with germline mutation, or additional somatic mutations in genes associated with myeloid malignancy. A subset of patients may present with MDS/AML at a young age, underscoring the growing concern for evaluating young patients with MDS/AML for germline mutations predisposing to myeloid neoplasm. Early recognition of germline mutation and predisposition to myeloid malignancy permits appropriate treatment, adequate monitoring for disease progression, proper donor selection for hematopoietic stem cell transplantation, as well as genetic counseling of the affected patients and their family members. Herein, we describe the clinical and diagnostic features of IT with germline mutations predisposing to myeloid neoplasms focusing on mutations involving RUNX1, ANKRD26, and ETV6.
Collapse
Affiliation(s)
- Pallavi Galera
- Department of Laboratory Medicine, Hematology Section, Clinical Center, National Institutes of Health (NIH), Bethesda, Maryland
| | - Alina Dulau-Florea
- Department of Laboratory Medicine, Hematology Section, Clinical Center, National Institutes of Health (NIH), Bethesda, Maryland
| | - Katherine R Calvo
- Department of Laboratory Medicine, Hematology Section, Clinical Center, National Institutes of Health (NIH), Bethesda, Maryland
| |
Collapse
|
14
|
Chanpeng P, Svasti S, Paiboonsukwong K, Smith DR, Leecharoenkiat K. Platelet proteome reveals specific proteins associated with platelet activation and the hypercoagulable state in β-thalassmia/HbE patients. Sci Rep 2019; 9:6059. [PMID: 30988349 PMCID: PMC6465338 DOI: 10.1038/s41598-019-42432-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 03/29/2019] [Indexed: 12/24/2022] Open
Abstract
A hypercoagulable state leading to a high risk of a thrombotic event is one of the most common complications observed in β-thalassemia/HbE disease, particularly in patients who have undergone a splenectomy. However, the hypercoagulable state, as well as the molecular mechanism of this aspect of the pathogenesis of β-thalassemia/HbE, remains poorly understood. To address this issue, fifteen non-splenectomized β-thalassemia/HbE patients, 8 splenectomized β-thalassemia/HbE patients and 20 healthy volunteers were recruited to this study. Platelet activation and hypercoagulable parameters including levels of CD62P and prothrombin fragment 1 + 2 were analyzed by flow cytometry and ELISA, respectively. A proteomic analysis was conducted to compare the platelet proteome between patients and normal subjects, and the results were validated by western blot analysis. The β-thalassemia/HbE patients showed significantly higher levels of CD62P and prothrombin fragment 1 + 2 than normal subjects. The levels of platelet activation and hypercoagulation found in patients were strongly associated with splenectomy status. The platelet proteome analysis revealed 19 differential spots which were identified to be 19 platelet proteins, which included 10 cytoskeleton proteins, thrombin generation related proteins, and antioxidant enzymes. Our findings highlight markers of coagulation activation and molecular pathways known to be associated with the pathogenesis of platelet activation, the hypercoagulable state, and consequently with the thrombosis observed in β-thalassemia/HbE patients.
Collapse
Affiliation(s)
- Puangpaka Chanpeng
- Oxidation in Red Cell Disorders and Health Task Force, Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Saovaros Svasti
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Bangkok, Thailand
| | - Kittiphong Paiboonsukwong
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Bangkok, Thailand
| | - Duncan R Smith
- Molecular Pathology Laboratory, Institute of Molecular Biosciences, Mahidol University, Bangkok, Thailand
| | - Kamonlak Leecharoenkiat
- Oxidation in Red Cell Disorders and Health Task Force, Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand.
| |
Collapse
|
15
|
Defective RAB1B-related megakaryocytic ER-to-Golgi transport in RUNX1 haplodeficiency: impact on von Willebrand factor. Blood Adv 2019; 2:797-806. [PMID: 29632235 DOI: 10.1182/bloodadvances.2017014274] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/27/2018] [Indexed: 12/18/2022] Open
Abstract
Patients with RUNX1 haplodeficiency have thrombocytopenia, platelet dysfunction, and deficiencies of α-granules and dense granules. Platelet expression profiling of a patient with a heterozygous RUNX1 mutation (c.969-323G>T) revealed decreased RAB1B, which encodes a small G protein. RAB GTPases regulate vesicle trafficking, and RAB1B is implicated in endoplasmic reticulum (ER)-to-Golgi transport in nonhematopoietic cells, but its role in megakaryocytes (MK) is unknown. We addressed the hypothesis that RAB1B is a transcriptional target of RUNX1 and that RAB1B regulates ER-to-Golgi transport in MK cells. Chromatin immunoprecipitation studies and electrophoretic mobility shift assay using phorbol 12-myristate 13-acetate (PMA)-treated human erythroleukemia cells revealed RUNX1 binding to RAB1B promoter region RUNX1 consensus sites, and their mutation reduced the promoter activity. RAB1B promoter activity and protein expression were inhibited by RUNX1 siRNA and enhanced by RUNX1 overexpression. These indicate that RAB1B is a direct RUNX1 target, providing a mechanism for decreased RAB1B in patient platelets. Vesicle trafficking from ER to Golgi in PMA-treated human erythroleukemia cells was impaired along with Golgi disruption on siRNA downregulation of RUNX1 or RAB1B. The effects of RUNX1 knockdown were reversed by RAB1B reconstitution. Trafficking of von Willebrand factor (vWF), an α-granule MK synthesized protein, was impaired with RUNX1 or RAB1B downregulation and reconstituted by ectopic RAB1B expression. Platelet vWF was decreased in patients with RUNX1 mutations. Thus, ER-to-Golgi transport, an early critical step in protein trafficking to granules, is impaired in megakaryocytic cells on RUNX1 downregulation, secondary to decreased RAB1B expression. Impaired RAB1B mediated ER-to-Golgi transport contributes to platelet α-granule defects in RUNX1 haplodeficiency.
Collapse
|
16
|
|
17
|
Cattaneo M. Inherited Disorders of Platelet Function. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00048-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
18
|
Lambert MP, Poncz M. Inherited Thrombocytopenias. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00046-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Glembotsky AC, Sliwa D, Bluteau D, Balayn N, Marin Oyarzún CP, Raimbault A, Bordas M, Droin N, Pirozhkova I, Washington V, Goette NP, Marta RF, Favier R, Raslova H, Heller PG. Downregulation of TREM-like transcript-1 and collagen receptor α2 subunit, two novel RUNX1-targets, contributes to platelet dysfunction in familial platelet disorder with predisposition to acute myelogenous leukemia. Haematologica 2018; 104:1244-1255. [PMID: 30545930 PMCID: PMC6545826 DOI: 10.3324/haematol.2018.188904] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 12/10/2018] [Indexed: 12/21/2022] Open
Abstract
Germline RUNX1 mutations lead to thrombocytopenia and platelet dysfunction in familial platelet disorder with predisposition to acute myelogenous leukemia (AML). Multiple aspects of platelet function are impaired in these patients, associated with altered expression of genes regulated by RUNX1. We aimed to identify RUNX1-targets involved in platelet function by combining transcriptome analysis of patient and shRUNX1-transduced megakaryocytes (MK). Down-regulated genes included TREM-like transcript (TLT)-1 (TREML1) and the integrin subunit alpha (α)-2 (ITGA2) of collagen receptor α2-beta (β)-1, which are involved in platelet aggregation and adhesion, respectively. RUNX1 binding to regions enriched for H3K27Ac marks was demonstrated for both genes using chromatin immunoprecipitation. Cloning of these regions upstream of the respective promoters in lentivirus allowing mCherry reporter expression showed that RUNX1 positively regulates TREML1 and ITGA2, and this regulation was abrogated after deletion of RUNX1 sites. TLT-1 content was reduced in patient MK and platelets. A blocking anti-TLT-1 antibody was able to block aggregation of normal but not patient platelets, whereas recombinant soluble TLT-1 potentiated fibrinogen binding to patient platelets, pointing to a role for TLT-1 deficiency in the platelet function defect. Low levels of α2 integrin subunit were demonstrated in patient platelets and MK, coupled with reduced platelet and MK adhesion to collagen, both under static and flow conditions. In conclusion, we show that gene expression profiling of RUNX1 knock-down or mutated MK provides a suitable approach to identify novel RUNX1 targets, among which downregulation of TREML1 and ITGA2 clearly contribute to the platelet phenotype of familial platelet disorder with predisposition to AML.
Collapse
Affiliation(s)
- Ana C Glembotsky
- Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina,Hematología Investigación, Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Buenos Aires, Argentina
| | - Dominika Sliwa
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc
| | - Dominique Bluteau
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc,Ecole Pratique des Hautes Etudes (EPHE), Paris, France
| | - Nathalie Balayn
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc
| | - Cecilia P Marin Oyarzún
- Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina,Hematología Investigación, Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Buenos Aires, Argentina
| | - Anna Raimbault
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc
| | - Marie Bordas
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc
| | - Nathalie Droin
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc,Gustave Roussy, Université Paris-Saclay, Genomic Platform UMS AMMICA, Villejuif, France
| | - Iryna Pirozhkova
- CNRS UMR 8126, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Valance Washington
- Department of Biology, University of Puerto Rico-Rio Piedras, San Juan, Puerto Rico and
| | - Nora P Goette
- Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Rosana F Marta
- Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina,Hematología Investigación, Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Buenos Aires, Argentina
| | - Rémi Favier
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc,Assistance Publique-Hôpitaux de Paris, Hôpital Trousseau, CRPP, Services d’Hématologie Biologique et Clinique, Paris, France
| | - Hana Raslova
- INSERM UMR 1170, Gustave Roussy, Université Paris-Saclay, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Villejuif, Franc
| | - Paula G Heller
- Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina,Hematología Investigación, Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Buenos Aires, Argentina
| |
Collapse
|
20
|
Li Y, Jin C, Bai H, Gao Y, Sun S, Chen L, Qin L, Liu PP, Cheng L, Wang QF. Human NOTCH4 is a key target of RUNX1 in megakaryocytic differentiation. Blood 2018; 131:191-201. [PMID: 29101237 PMCID: PMC5757696 DOI: 10.1182/blood-2017-04-780379] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 10/13/2017] [Indexed: 12/19/2022] Open
Abstract
Megakaryocytes (MKs) in adult marrow produce platelets that play important roles in blood coagulation and hemostasis. Monoallelic mutations of the master transcription factor gene RUNX1 lead to familial platelet disorder (FPD) characterized by defective MK and platelet development. However, the molecular mechanisms of FPD remain unclear. Previously, we generated human induced pluripotent stem cells (iPSCs) from patients with FPD containing a RUNX1 nonsense mutation. Production of MKs from the FPD-iPSCs was reduced, and targeted correction of the RUNX1 mutation restored MK production. In this study, we used isogenic pairs of FPD-iPSCs and the MK differentiation system to identify RUNX1 target genes. Using integrative genomic analysis of hematopoietic progenitor cells generated from FPD-iPSCs, and mutation-corrected isogenic controls, we identified 2 gene sets the transcription of which is either up- or downregulated by RUNX1 in mutation-corrected iPSCs. Notably, NOTCH4 expression was negatively controlled by RUNX1 via a novel regulatory DNA element within the locus, and we examined its involvement in MK generation. Specific inactivation of NOTCH4 by an improved CRISPR-Cas9 system in human iPSCs enhanced megakaryopoiesis. Moreover, small molecules known to inhibit Notch signaling promoted MK generation from both normal human iPSCs and postnatal CD34+ hematopoietic stem and progenitor cells. Our study newly identified NOTCH4 as a RUNX1 target gene and revealed a previously unappreciated role of NOTCH4 signaling in promoting human megakaryopoiesis. Our work suggests that human iPSCs with monogenic mutations have the potential to serve as an invaluable resource for discovery of novel druggable targets.
Collapse
Affiliation(s)
- Yueying Li
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Chen Jin
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hao Bai
- Division of Hematology, Department of Medicine and
- Stem Cell Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD; and
| | - Yongxing Gao
- Division of Hematology, Department of Medicine and
- Stem Cell Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD; and
| | - Shu Sun
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lei Chen
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lei Qin
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Paul P Liu
- Translational and Functional Genomics Branch, National Institutes of Health, National Human Genome Research Institute, Bethesda, MD
| | - Linzhao Cheng
- Division of Hematology, Department of Medicine and
- Stem Cell Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD; and
| | - Qian-Fei Wang
- Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
21
|
Nava T, Rivard GE, Bonnefoy A. Challenges on the diagnostic approach of inherited platelet function disorders: Is a paradigm change necessary? Platelets 2017; 29:148-155. [PMID: 29090587 DOI: 10.1080/09537104.2017.1356918] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Inherited platelet function disorders (IPFD) have been assessed for more than 50 years by aggregation- and secretion-based tests. Several decision trees are available intending to standardize the investigation of IPFD. A large variability of approaches is still in use among the laboratories across the world. In spite of costly and lengthy laboratory evaluation, the results have been found inconclusive or negative in a significant part of patients having bleeding manifestations. Molecular investigation of newly identified IPFD has recently contributed to a better understanding of the complexity of platelet function. Once considered "classic" IPFDs, Glanzmann thrombasthenia and Bernard-Soulier syndrome have each had their pathophysiology reassessed and their diagnosis made more precise and informative. Megakaryopoiesis, platelet formation, and function have been found tightly interlinked, with several genes being involved in both inherited thrombocytopenias and impaired platelet function. Moreover, genetic approaches have moved from being used as confirmatory diagnostic tests to being tools for identification of genetic variants associated with bleeding disorders, even in the absence of a clear phenotype in functional testing. In this study, we aim to address some limits of the conventional tests used for the diagnosis of IPFD, and to highlight the potential contribution of recent molecular tools and opportunities to rethink the way we should approach the investigation of IPFD.
Collapse
Affiliation(s)
- Tiago Nava
- a Centre Hospitalier Universitaire Sainte-Justine , Hematology and Oncology Division , Montréal , QC , Canada.,b Child and Adolescent Health, School of Medicine , Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Brazil
| | - Georges-Etienne Rivard
- a Centre Hospitalier Universitaire Sainte-Justine , Hematology and Oncology Division , Montréal , QC , Canada
| | - Arnaud Bonnefoy
- a Centre Hospitalier Universitaire Sainte-Justine , Hematology and Oncology Division , Montréal , QC , Canada
| |
Collapse
|
22
|
Rao AK, Poncz M. Defective acid hydrolase secretion in RUNX1 haplodeficiency: Evidence for a global platelet secretory defect. Haemophilia 2017; 23:784-792. [PMID: 28662545 PMCID: PMC5623153 DOI: 10.1111/hae.13280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2017] [Indexed: 01/15/2023]
Abstract
BACKGROUND RUNX1 haplodeficiency is associated with thrombocytopenia, platelet dysfunction and a predisposition to acute leukaemia. Platelets possess three distinct types of granules and secretory processes involving dense granules (DG), α-granules and vesicles or lysosomes containing acid hydrolases (AH). Dense granules and granule deficiencies have been reported in patients with RUNX1 mutations. Little is known regarding the secretion from AH-containing vesicles. METHODS AND RESULTS We studied two related patients with a RUNX1 mutation, easy bruising, and mild thrombocytopenia. Platelet aggregation and 14 C serotonin in platelet-rich plasma (PRP) were impaired in response to ADP, epinephrine, collagen and arachidonic acid. Contents of DG (ATP, ADP), α-granules (β-thromboglobulin) and AH-containing vesicles (β-glucuronidase, β-hexosaminidase, α-mannosidase) were normal or minimally decreased. Dense granules secretion on stimulation of gel-filtered platelets with thrombin and divalent ionophore A23187 (4-12 μmol L-1 ) were diminished. β-thromboglobulin and AH secretion was impaired in response to thrombin or A23187. We studied thromboxane-related pathways. The incorporation of 14 C -arachidonic acid into phospholipids and subsequent arachidonic acid release on thrombin activation was normal. Platelet thromboxane A2 production in whole blood serum and on thrombin stimulation of PRP was normal, suggesting that the defective secretion was not due to impaired thromboxane production. CONCLUSIONS These studies provide the first evidence in patients with a RUNX1 mutation for a defect in AH (lysosomal) secretion, and for a global defect in secretion involving all three types of platelet granules that is unrelated to a granule content deficiency. They highlight the pleiotropic effects and multiple platelet defects associated with RUNX1 mutations.
Collapse
Affiliation(s)
- A K Rao
- Sol Sherry Thrombosis Research Center and the Hematology Division, Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - M Poncz
- Hematology Division, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| |
Collapse
|
23
|
Kim MS, Gernapudi R, Choi EY, Lapidus RG, Passaniti A. Characterization of CADD522, a small molecule that inhibits RUNX2-DNA binding and exhibits antitumor activity. Oncotarget 2017; 8:70916-70940. [PMID: 29050333 PMCID: PMC5642608 DOI: 10.18632/oncotarget.20200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/12/2017] [Indexed: 12/29/2022] Open
Abstract
The RUNX2 transcription factor promotes breast cancer growth and metastasis through interactions with a variety of cofactors that activate or repress target genes. Using a direct drug discovery approach we identified CADD522 as a small molecule that inhibits the DNA binding of the runt box domain protein, RUNX2. The current study defines the effect of CADD522 on breast cancer growth and metastasis, and addresses the mechanisms by which it exerts its anti-tumor activity. CADD522 treatment resulted in significant growth inhibition, clonogenic survival, tumorsphere formation, and invasion of breast cancer cells. CADD522 negatively regulated transcription of RUNX2 target genes such as matrix metalloproteinase-13, vascular endothelial growth factor and glucose transporter-1, but upregulated RUNX2 expression by increasing RUNX2 stability. CADD522 reduced RUNX2-mediated increases in glucose uptake and decreased the level of CBF-β and RUNX2 phosphorylation at the S451 residue. These results suggest several potential mechanisms by which CADD522 exerts an inhibitory function on RUNX2-DNA binding; interference with RUNX2 for the DNA binding pocket, inhibition of glucose uptake leading to cell cycle arrest, down-regulation of CBF-β, and reduction of S451-RUNX2 phosphorylation. The administration of CADD522 into MMTV-PyMT mice resulted in significant delay in tumor incidence and reduction in tumor burden. A significant decrease of tumor volume was also observed in a CADD522-treated human triple-negative breast cancer-patient derived xenograft model. CADD522 impaired the lung retention and outgrowth of breast cancer cells in vivo with no apparent toxicity to the mice. Therefore, by inhibiting RUNX2-DNA binding, CADD522 may represent a potential antitumor drug.
Collapse
Affiliation(s)
- Myoung Sook Kim
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.,The Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA.,The Veteran's Health Administration Research & Development Service, Baltimore, MD, USA
| | - Ramkishore Gernapudi
- Department of Biochemistry & Molecular Biology and Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.,The Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Eun Yong Choi
- The Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Rena G Lapidus
- The Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Antonino Passaniti
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Biochemistry & Molecular Biology and Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.,The Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA.,The Veteran's Health Administration Research & Development Service, Baltimore, MD, USA
| |
Collapse
|
24
|
Mao G, Songdej N, Voora D, Goldfinger LE, Del Carpio-Cano FE, Myers RA, Rao AK. Transcription Factor RUNX1 Regulates Platelet PCTP (Phosphatidylcholine Transfer Protein): Implications for Cardiovascular Events: Differential Effects of RUNX1 Variants. Circulation 2017; 136:927-939. [PMID: 28676520 DOI: 10.1161/circulationaha.116.023711] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 06/16/2017] [Indexed: 02/02/2023]
Abstract
BACKGROUND PCTP (phosphatidylcholine transfer protein) regulates the intermembrane transfer of phosphatidylcholine. Higher platelet PCTP expression is associated with increased platelet responses on activation of protease-activated receptor 4 thrombin receptors noted in black subjects compared with white subjects. Little is known about the regulation of platelet PCTP. Haplodeficiency of RUNX1, a major hematopoietic transcription factor, is associated with thrombocytopenia and impaired platelet responses on activation. Platelet expression profiling of a patient with a RUNX1 loss-of-function mutation revealed a 10-fold downregulation of the PCTP gene compared with healthy controls. METHODS We pursued the hypothesis that PCTP is regulated by RUNX1 and that PCTP expression is correlated with cardiovascular events. We studied RUNX1 binding to the PCTP promoter using DNA-protein binding studies and human erythroleukemia cells and promoter activity using luciferase reporter studies. We assessed the relationship between RUNX1 and PCTP in peripheral blood RNA and PCTP and death or myocardial infarction in 2 separate patient cohorts (587 total patients) with cardiovascular disease. RESULTS Platelet PCTP protein in the patient was reduced by ≈50%. DNA-protein binding studies showed RUNX1 binding to consensus sites in ≈1 kB of PCTP promoter. PCTP expression was increased with RUNX1 overexpression and reduced with RUNX1 knockdown in human erythroleukemia cells, indicating that PCTP is regulated by RUNX1. Studies in 2 cohorts of patients showed that RUNX1 expression in blood correlated with PCTP gene expression; PCTP expression was higher in black compared with white subjects and was associated with future death/myocardial infarction after adjustment for age, sex, and race (odds ratio, 2.05; 95% confidence interval 1.6-2.7; P<0.0001). RUNX1 expression is known to initiate at 2 alternative promoters, a distal P1 and a proximal P2 promoter. In patient cohorts, there were differential effects of RUNX1 isoforms on PCTP expression with a negative correlation in blood between RUNX1 expressed from the P1 promoter and PCTP expression. CONCLUSIONS PCTP is a direct transcriptional target of RUNX1. PCTP expression is associated with death/myocardial infarction in patients with cardiovascular disease. RUNX1 regulation of PCTP may play a role in the pathogenesis of platelet-mediated cardiovascular events.
Collapse
Affiliation(s)
- Guangfen Mao
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.)
| | - Natthapol Songdej
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.)
| | - Deepak Voora
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.)
| | - Lawrence E Goldfinger
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.)
| | - Fabiola E Del Carpio-Cano
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.)
| | - Rachel A Myers
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.)
| | - A Koneti Rao
- From Sol Sherry Thrombosis Research Center (G.M., N.S., F.E.D.C.-C., L.E.G., A.K.R.), Hematology Section, Department of Medicine (N.S., A.K.R.), and Department of Anatomy and Cell Biology (L.E.G.), Lewis Katz School of Medicine at Temple University, Philadelphia, PA; and Duke Center for Applied Genomics and Precision Medicine, Department of Medicine, Duke University, Durham, NC (D.V., R.A.M.).
| |
Collapse
|
25
|
Hematopoietic transcription factor mutations: important players in inherited platelet defects. Blood 2017; 129:2873-2881. [PMID: 28416505 DOI: 10.1182/blood-2016-11-709881] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/26/2017] [Indexed: 01/19/2023] Open
Abstract
Transcription factors (TFs) are proteins that bind to specific DNA sequences and regulate expression of genes. The molecular and genetic mechanisms in most patients with inherited platelet defects are unknown. There is now increasing evidence that mutations in hematopoietic TFs are an important underlying cause for defects in platelet production, morphology, and function. The hematopoietic TFs implicated in patients with impaired platelet function and number include runt-related transcription factor 1, Fli-1 proto-oncogene, E-twenty-six (ETS) transcription factor (friend leukemia integration 1), GATA-binding protein 1, growth factor independent 1B transcriptional repressor, ETS variant 6, ecotropic viral integration site 1, and homeobox A11. These TFs act in a combinatorial manner to bind sequence-specific DNA within promoter regions to regulate lineage-specific gene expression, either as activators or repressors. TF mutations induce rippling downstream effects by simultaneously altering the expression of multiple genes. Mutations involving these TFs affect diverse aspects of megakaryocyte biology, and platelet production and function, culminating in thrombocytopenia and platelet dysfunction. Some are associated with predisposition to hematologic malignancies. These TF variants may occur more frequently in patients with inherited platelet defects than generally appreciated. This review focuses on alterations in hematopoietic TFs in the pathobiology of inherited platelet defects.
Collapse
|
26
|
Mao GF, Goldfinger LE, Fan DC, Lambert MP, Jalagadugula G, Freishtat R, Rao AK. Dysregulation of PLDN (pallidin) is a mechanism for platelet dense granule deficiency in RUNX1 haplodeficiency. J Thromb Haemost 2017; 15:792-801. [PMID: 28075530 PMCID: PMC5378588 DOI: 10.1111/jth.13619] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Indexed: 01/01/2023]
Abstract
Essentials Platelet dense granule (DG) deficiency is a major abnormality in RUNX1 haplodeficiency patients. The molecular mechanisms leading to the platelet DG deficiency are unknown. Platelet expression of PLDN (BLOC1S6, pallidin), involved in DG biogenesis, is regulated by RUNX1. Downregulation of PLDN is a mechanism for DG deficiency in RUNX1 haplodeficiency. SUMMARY Background Inherited RUNX1 haplodeficiency is associated with thrombocytopenia and platelet dysfunction. Dense granule (DG) deficiency has been reported in patients with RUNX1 haplodeficiency, but the molecular mechanisms are unknown. Platelet mRNA expression profiling in a patient previously reported by us with a RUNX1 mutation and platelet dysfunction showed decreased expression of PLDN (BLOC1S6), which encodes pallidin, a subunit of biogenesis of lysosome-related organelles complex-1 (BLOC-1) involved in DG biogenesis. PLDN mutations in the pallid mouse and Hermansky-Pudlak syndrome-9 are associated with platelet DG deficiency. Objectives We postulated that PLDN is a RUNX1 target, and that its decreased expression leads to platelet DG deficiency in RUNX1 haplodeficiency. Results Platelet pallidin and DG levels were decreased in our patient. This was also observed in two siblings from a different family with a RUNX1 mutation. Chromatin immunoprecipitation and electrophoretic mobility shift assays with phorbol ester-treated human erythroleukemia (HEL) cells showed RUNX1 binding to RUNX1 consensus sites in the PLDN1 5' upstream region. In luciferase reporter studies, mutation of RUNX1 sites in the PLDN promoter reduced activity. RUNX1 overexpression enhanced and RUNX1 downregulation decreased PLDN1 promoter activity and protein expression. RUNX1 downregulation resulted in impaired handling of mepacrine and mislocalization of the DG marker CD63 in HEL cells, indicating impaired DG formation, recapitulating findings on PLDN downregulation. Conclusions These studies provide the first evidence that PLDN is a direct target of RUNX1 and that its dysregulation is a mechanism for platelet DG deficiency associated with RUNX1 haplodeficiency.
Collapse
Affiliation(s)
- G F Mao
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - L E Goldfinger
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - D C Fan
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - M P Lambert
- Division of Hematology, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Children's Hospital of Philadelphia and Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - G Jalagadugula
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - R Freishtat
- Department of Pediatrics, Children's National Medical Center, Washington, DC, USA
| | - A K Rao
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
- Department of Medicine, Temple University School of Medicine, Philadelphia, PA, USA
| |
Collapse
|
27
|
Songdej N, Rao AK. Inherited platelet dysfunction and hematopoietic transcription factor mutations. Platelets 2017; 28:20-26. [PMID: 27463948 PMCID: PMC5628047 DOI: 10.1080/09537104.2016.1203400] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/16/2016] [Accepted: 05/30/2016] [Indexed: 01/19/2023]
Abstract
Transcription factors (TFs) are proteins that bind to specific DNA sequences and regulate expression of genes. The molecular and genetic mechanisms in most patients with inherited platelet dysfunction are unknown. There is now increasing evidence that mutations in hematopoietic TFs are an important underlying cause for the defects in platelet production, morphology, and function. The hematopoietic TFs implicated in the patients with impaired platelet function include Runt related TF 1 (RUNX1), Fli-1 proto-oncogene, ETS TF (FLI1), GATA-binding protein 1 (GATA1), and growth factor independent 1B transcriptional repressor (GFI1B). These TFs act in a combinatorial manner to bind sequence-specific DNA within a promoter region to regulate lineage-specific gene expression, either as activators or as repressors. TF mutations induce rippling downstream effects by simultaneously altering the expression of multiple genes. Mutations involving these TFs affect diverse aspects of megakaryocyte biology and platelet production and function, culminating in thrombocytopenia, platelet dysfunction, and associated clinical features. Mutations in TFs may occur more frequently in the patients with inherited platelet dysfunction than generally appreciated. This review focuses on the alterations in hematopoietic TFs in the pathobiology of inherited platelet dysfunction.
Collapse
Affiliation(s)
- Natthapol Songdej
- a Sol Sherry Thrombosis Research Center, and Hematology Section, Department of Medicine , Lewis Katz School of Medicine at Temple University , Philadelphia , PA , USA
| | - A Koneti Rao
- a Sol Sherry Thrombosis Research Center, and Hematology Section, Department of Medicine , Lewis Katz School of Medicine at Temple University , Philadelphia , PA , USA
| |
Collapse
|
28
|
Duployez N, Lejeune S, Renneville A, Preudhomme C. Myelodysplastic syndromes and acute leukemia with genetic predispositions: a new challenge for hematologists. Expert Rev Hematol 2016; 9:1189-1202. [DOI: 10.1080/17474086.2016.1257936] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
29
|
Systems Pharmacogenomics Finds RUNX1 Is an Aspirin-Responsive Transcription Factor Linked to Cardiovascular Disease and Colon Cancer. EBioMedicine 2016; 11:157-164. [PMID: 27566955 PMCID: PMC5049978 DOI: 10.1016/j.ebiom.2016.08.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/10/2016] [Accepted: 08/12/2016] [Indexed: 12/21/2022] Open
Abstract
Aspirin prevents cardiovascular disease and colon cancer; however aspirin's inhibition of platelet COX-1 only partially explains its diverse effects. We previously identified an aspirin response signature (ARS) in blood consisting of 62 co-expressed transcripts that correlated with aspirin's effects on platelets and myocardial infarction (MI). Here we report that 60% of ARS transcripts are regulated by RUNX1 - a hematopoietic transcription factor - and 48% of ARS gene promoters contain a RUNX1 binding site. Megakaryocytic cells exposed to aspirin and its metabolite (salicylic acid, a weak COX-1 inhibitor) showed up regulation in the RUNX1 P1 isoform and MYL9, which is transcriptionally regulated by RUNX1. In human subjects, RUNX1 P1 expression in blood and RUNX1-regulated platelet proteins, including MYL9, were aspirin-responsive and associated with platelet function. In cardiovascular disease patients RUNX1 P1 expression was associated with death or MI. RUNX1 acts as a tumor suppressor gene in gastrointestinal malignancies. We show that RUNX1 P1 expression is associated with colon cancer free survival suggesting a role for RUNX1 in aspirin's protective effect in colon cancer. Our studies reveal an effect of aspirin on RUNX1 and gene expression that may additionally explain aspirin's effects in cardiovascular disease and cancer.
Collapse
|
30
|
Daly ME. Transcription factor defects causing platelet disorders. Blood Rev 2016; 31:1-10. [PMID: 27450272 DOI: 10.1016/j.blre.2016.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/10/2016] [Accepted: 07/12/2016] [Indexed: 01/19/2023]
Abstract
Recent years have seen increasing recognition of a subgroup of inherited platelet function disorders which are due to defects in transcription factors that are required to regulate megakaryopoiesis and platelet production. Thus, germline mutations in the genes encoding the haematopoietic transcription factors RUNX1, GATA-1, FLI1, GFI1b and ETV6 have been associated with both quantitative and qualitative platelet abnormalities, and variable bleeding symptoms in the affected patients. Some of the transcription factor defects are also associated with an increased predisposition to haematologic malignancies (RUNX1, ETV6), abnormal erythropoiesis (GATA-1, GFI1b, ETV6) and immune dysfunction (FLI1). The persistence of MYH10 expression in platelets is a surrogate marker for FLI1 and RUNX1 defects. Characterisation of the transcription factor defects that give rise to platelet function disorders, and of the genes that are differentially regulated as a result, are yielding insights into the roles of these genes in platelet formation and function.
Collapse
Affiliation(s)
- Martina E Daly
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK.
| |
Collapse
|
31
|
Songdej N, Rao AK. Hematopoietic transcription factor mutations and inherited platelet dysfunction. F1000PRIME REPORTS 2015; 7:66. [PMID: 26097739 PMCID: PMC4447035 DOI: 10.12703/p7-66] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The molecular and genetic mechanisms in most patients with inherited platelet dysfunction are unknown. There is increasing evidence that mutations in hematopoietic transcription factors are major players in the pathogenesis of defective megakaryopoiesis and platelet dysfunction in patients with inherited platelet disorders. These hematopoietic transcription factors include RUNX1, FLI1, GATA-1, and GFI1B. Mutations involving these transcription factors affect diverse aspects of platelet production and function at the genetic and molecular levels, culminating in clinical manifestations of thrombocytopenia and platelet dysfunction. This review focuses on these hematopoietic transcription factors in the pathobiology of inherited platelet dysfunction.
Collapse
|
32
|
Rao AK. Inherited platelet function disorders: overview and disorders of granules, secretion, and signal transduction. Hematol Oncol Clin North Am 2013; 27:585-611. [PMID: 23714313 DOI: 10.1016/j.hoc.2013.02.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Inherited disorders of platelet function are characterized by highly variable mucocutaneous bleeding manifestations. The platelet dysfunction arises by diverse mechanisms, including abnormalities in platelet membrane glycoproteins, granules and their contents, platelet signaling and secretion mechanisms: thromboxane production pathways and in platelet procoagulant activities. Platelet aggregation and secretion studies using platelet-rich plasma currently form the primary basis for the diagnosis of an inherited platelet dysfunction. In most such patients, the molecular and genetic mechanisms are unknown. Management of these patients needs to be individualized; therapeutic options include platelet transfusions, 1-desamino-8d-arginine vasopressin (DDAVP), recombinant factor VIIa, and antifibrinolytic agents.
Collapse
Affiliation(s)
- A Koneti Rao
- Hematology Section, Department of Medicine and Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA.
| |
Collapse
|
33
|
Okada Y, Watanabe M, Nakai T, Kamikawa Y, Shimizu M, Fukuhara Y, Yonekura M, Matsuura E, Hoshika Y, Nagai R, Aird WC, Doi T. RUNX1, but not its familial platelet disorder mutants, synergistically activates PF4 gene expression in combination with ETS family proteins. J Thromb Haemost 2013; 11:1742-50. [PMID: 23848403 DOI: 10.1111/jth.12355] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Familial platelet disorder (FPD) is a rare autosomal dominant disease characterized by thrombocytopenia and abnormal platelet function. Causal mutations have been identified in the gene encoding runt-related transcription factor 1 (RUNX1) of FPD patients. OBJECTIVES To elucidate the role of RUNX1 in the regulation of expression of platelet factor 4 (PF4) and to propose a plausible mechanism underlying RUNX1-mediated induction of the FPD phenotype. METHODS We assessed whether RUNX1 and its mutants, in combination with E26 transformation-specific-1 (ETS-1), Core-binding factor subunit beta (CBFβ), and Friend leukemia virus integration 1 (FLI-1), cooperatively regulate PF4 expression during megakaryocytic differentiation. In an embryonic stem cell differentiation system, expression levels of endogenous and exogenous RUNX1 and PF4 were determined by real-time RT-PCR. Promoter activation by the transcription factors were evaluated by reporter gene assays with HepG2 cells. DNA binding activity and protein interaction were analyzed by electrophoretic mobility shift assay and immunoprecipitation assay with Cos-7 cells, respectively. Protein localization was analyzed by immunocytochemistry and Western blotting with Cos-7 cells. RESULTS We demonstrated that RUNX1 activates endogenous PF4 expression in megakaryocytic differentiation. RUNX1, but not its mutants, in combination with ETS-1 and CBFβ, or FLI-1, synergistically activated the PF4 promoter. Each RUNX1 mutant harbors various functional abnormalities, including loss of DNA-binding activity, abnormal subcellular localization, and/or alterations of binding affinities for ETS-1, CBFβ, and FLI-1. CONCLUSIONS RUNX1, but not its mutants, strongly and synergistically activates PF4 expression along with ETS family proteins. Furthermore, loss of the RUNX1 transcriptional activation function is induced by various functional abnormalities.
Collapse
Affiliation(s)
- Y Okada
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
A neonate with congenital amegakaryocytic thrombocytopenia associated with a chromosomal microdeletion at 21q22.11 including the gene RUNX1. J Perinatol 2013; 33:242-4. [PMID: 23443295 DOI: 10.1038/jp.2012.53] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We observed a neonate who had severe thrombocytopenia wherein evaluations for neonatal immune-mediated thrombocytopenia and congenital infections were negative, and the marrow findings were consistent with congenital amegakaryocytic thrombocytopenia (CAMT). A genomic microarray identified a microdeletion at 21q22.11 including the gene RUNX1. Two somewhat similar cases were recently reported, but with multiple congenital anomalies that are not present in our case. We propose that a 21q22 deletion resulting in RUNX1 haploinsufficiency can produce a phenotype similar to CAMT with various associated anomalies depending on which adjacent genes are absent or disrupted.
Collapse
|
35
|
|
36
|
Dysmegakaryopoiesis of FPD/AML pedigrees with constitutional RUNX1 mutations is linked to myosin II deregulated expression. Blood 2012; 120:2708-18. [DOI: 10.1182/blood-2012-04-422337] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Abstract
FPD/AML is a familial platelet disorder characterized by platelet defects, predisposition to acute myelogenous leukemia (AML) and germ-line heterozygous RUNX1 alterations. Here we studied the in vitro megakaryopoiesis of 3 FPD/AML pedigrees. A 60% to 80% decrease in the output of megakaryocytes (MKs) from CD34+ was observed. MK ploidy level was low and mature MKs displayed a major defect in proplatelet formation. To explain these defects, we focused on myosin II expression as RUNX1 has been shown to regulate MYL9 and MYH10 in an inverse way. In FPD/AML MKs, expression of MYL9 and MYH9 was decreased, whereas MYH10 expression was increased and the MYH10 protein was still present in the cytoplasm of mature MKs. Myosin II activity inhibition by blebbistatin rescued the ploidy defect of FPD/AML MKs. Finally, we demonstrate that MYH9 is a direct target of RUNX1 by chromatin immunoprecipitation and luciferase assays and we identified new RUNX1 binding sites in the MYL9 promoter region. Together, these results demonstrate that the defects in megakaryopoiesis observed in FPD/AML are, in part, related to a deregulation of myosin IIA and IIB expression leading to both a defect in ploidization and proplatelet formation.
Collapse
|
37
|
Embryonic stem cell differentiation system for evaluating gene functions involved in physiological megakaryocytic differentiation. Biochem Biophys Res Commun 2012; 419:477-81. [DOI: 10.1016/j.bbrc.2012.02.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 02/03/2012] [Indexed: 11/20/2022]
|
38
|
Abstract
Understanding platelet biology has been aided by studies of mice with mutations in key megakaryocytic transcription factors. We have shown that point mutations in the GATA1 cofactor FOG1 that disrupt binding to the nucleosome remodeling and deacetylase (NuRD) complex have erythroid and megakaryocyte lineages defects. Mice that are homozygous for a FOG1 point mutation (ki/ki), which ablates FOG1-NuRD interactions, have platelets that display a gray platelet syndrome (GPS)-like macrothrombocytopenia. These platelets have few α-granules and an increased number of lysosomal-like vacuoles on electron microscopy, reminiscent of the platelet in patients with GATA1-related X-linked GPS. Here we further characterized the platelet defect in ki/ki mice. We found markedly deficient levels of P-selectin protein limited to megakaryocytes and platelets. Other α-granule proteins were expressed at normal levels and were appropriately localized to α-granule-like structures. Treatment of ki/ki platelets with thrombin failed to stimulate Akt phosphorylation, resulting in poor granule secretion and platelet aggregation. These studies show that disruption of the GATA1/FOG1/NuRD transcriptional system results in a complex, pleiotropic platelet defect beyond GPS-like macrothrombocytopenia and suggest that this transcriptional complex regulates not only megakaryopoiesis but also α-granule generation and signaling pathways required for granule secretion.
Collapse
|
39
|
Jalagadugula G, Mao G, Kaur G, Dhanasekaran DN, Rao AK. Platelet protein kinase C-theta deficiency with human RUNX1 mutation: PRKCQ is a transcriptional target of RUNX1. Arterioscler Thromb Vasc Biol 2011; 31:921-7. [PMID: 21252065 DOI: 10.1161/atvbaha.110.221879] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Mutations in the hematopoietic transcription factor RUNX1 cause thrombocytopenia and impaired platelet function. In a patient with a heterozygous mutation in RUNX1, we have described decreased platelet pleckstrin phosphorylation and protein kinase C- (PKC-, gene PRKCQ) associated with thrombocytopenia, impaired platelet aggregation, and dense granule secretion. Little is known regarding regulation of PKC- in megakaryocytes and platelets. We have addressed the hypothesis that PRKCQ is a direct transcriptional target of RUNX1. METHODS AND RESULTS In a chromatin immunoprecipitation assay using megakaryocytic cells, there was RUNX1 binding in vivo to PRKCQ promoter region -1225 to -1056 bp containing a RUNX1 consensus site ACCGCA at -1088 to -1069 bp; an electrophoretic mobility shift assay showed RUNX1 binding to the specific site. In RUNX1 overexpression studies, PKC- protein expression and promoter activity were enhanced; mutation of RUNX1 site showed decreased activity even with RUNX1 overexpression. Lastly, PRKCQ promoter activity and PKC- protein were decreased by short interfering RNA knockdown of RUNX1. CONCLUSIONS Our results provide the first evidence that PRKCQ is regulated at the transcriptional level by RUNX1 in megakaryocytic cells and a mechanism for PKC- deficiency associated with RUNX1 haplodeficiency.
Collapse
Affiliation(s)
- Gauthami Jalagadugula
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | | | | | | | | |
Collapse
|
40
|
Regulation of platelet myosin light chain (MYL9) by RUNX1: implications for thrombocytopenia and platelet dysfunction in RUNX1 haplodeficiency. Blood 2010; 116:6037-45. [PMID: 20876458 DOI: 10.1182/blood-2010-06-289850] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutations in transcription factor RUNX1 are associated with familial platelet disorder, thrombocytopenia, and predisposition to leukemia. We have described a patient with thrombocytopenia and impaired agonist-induced platelet aggregation, secretion, and glycoprotein (GP) IIb-IIIa activation, associated with a RUNX1 mutation. Platelet myosin light chain (MLC) phosphorylation and transcript levels of its gene MYL9 were decreased. Myosin IIA and MLC phosphorylation are important in platelet responses to activation and regulate thrombopoiesis by a negative regulatory effect on premature proplatelet formation. We addressed the hypothesis that MYL9 is a transcriptional target of RUNX1. Chromatin immunoprecipitation (ChIP) using megakaryocytic cells revealed RUNX1 binding to MYL9 promoter region -729/-542 basepairs (bp), which contains 4 RUNX1 sites. Electrophoretic mobility shift assay showed RUNX1 binding to each site. In transient ChIP assay, mutation of these sites abolished binding of RUNX1 to MYL9 promoter construct. In reporter gene assays, deletion of each RUNX1 site reduced activity. MYL9 expression was inhibited by RUNX1 short interfering RNA (siRNA) and enhanced by RUNX1 overexpression. RUNX1 siRNA decreased cell spreading on collagen and fibrinogen. Our results constitute the first evidence that the MYL9 gene is a direct target of RUNX1 and provide a mechanism for decreased platelet MYL9 expression, MLC phosphorylation, thrombocytopenia, and platelet dysfunction associated with RUNX1 mutations.
Collapse
|