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Ying WX, Shi SW, Wang HF, Chen JB, Pan JZ, Fang Q. Falcon Probe: A High-Pressure and Robust Sampling Interface for Coupling Lossless Liquid Chromatography Injection with In Situ Nanoliter-Scale Sample Pretreatment. Anal Chem 2024. [PMID: 39075986 DOI: 10.1021/acs.analchem.4c00856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
With the increasing demand for trace sample analysis, injecting trace samples into liquid chromatography-mass spectrometry (LC-MS) systems with minimal loss has become a major challenge. Herein, we describe an in situ LC-MS analytical probe, the Falcon probe, which integrates multiple functions of high-pressure sample injection without sample loss, high-efficiency LC separation, and electrospray. The main body of the Falcon probe is made of stainless steel and fabricated by the computer numerical control (CNC) technique, which has ultrahigh mechanical strength. By coupling a nanoliter-scale droplet reactor made of polyether ether ketone (PEEK) material, the Falcon probe-based LC-MS system was capable of operating at mobile-phase pressures up to 800 bar, which is comparable to those of conventional ultraperformance liquid chromatography (UPLC) systems. Using the probe pressing microamount in situ (PPMI) injection approach, the Falcon probe-based LC-MS system showed high separation efficiency and good repeatability with relative standard deviations (RSDs) of retention time and peak area of 1.8% and 9.9%, respectively, in peptide mixture analysis (n = 6). We applied this system to the analysis of a trace amount of 200 pg of HeLa protein digest and successfully identified an average of 766 protein groups (n = 5). By combining in situ sample pretreatment at the nanoliter range, we further applied the present system in single-cell proteomic analysis, and 241 protein groups were identified in single 293 cells, which preliminarily demonstrated its potential in the analysis of trace amounts of samples with complex compositions.
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Affiliation(s)
- Wei-Xin Ying
- Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Shao-Wen Shi
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
| | - Hui-Feng Wang
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
| | - Jian-Bo Chen
- Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Jian-Zhang Pan
- Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
| | - Qun Fang
- Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
- Key Laboratory for Biomedical Engineering of Ministry of Education, Cancer Center, Zhejiang University, Hangzhou 310007, China
- Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou 310007, China
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
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2
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Mehta S, Buyanbat A, Kai Y, Orkin SH. Mechanistic and kinetic insights into transcription factor biology via acute protein depletion. Exp Hematol 2024; 137:104250. [PMID: 38862078 DOI: 10.1016/j.exphem.2024.104250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/13/2024]
Abstract
Genetic downregulation of the BCL11A transcription factor (TF) reverses the switch from fetal to adult hemoglobin and is effective in treating β-hemoglobinopathies. Genetic ablation results in a gradual reduction in protein abundance and does not lend itself to the analysis of the immediate consequences of protein loss or the determination of the direct interactors/targets of the protein of interest. We achieved acute degradation of the largely disordered and 'undruggable' BCL11A protein by fusing it with a conditional degradation (degron) tag, FKBP12F36V, called degradable tags (dTAG). Small molecules then depleted the BCL11A-dTAG through endogenous proteolytic pathways. By integrating acute depletion with nascent transcriptomics and cell cycle separation techniques, we demonstrate the necessity of BCL11A occupancy at the target chromatin for sustained transcriptional repression in erythroid cells. We advocate for expanding the exploration of TF function to include acute depletion, which holds the potential to unveil unprecedented kinetic insights into TF mechanisms of action.
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Affiliation(s)
- Stuti Mehta
- Dana Farber/Boston Children's Hospital Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School, Boston, MA
| | - Altantsetseg Buyanbat
- Dana Farber/Boston Children's Hospital Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School, Boston, MA
| | - Yan Kai
- Dana Farber/Boston Children's Hospital Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School, Boston, MA
| | - Stuart H Orkin
- Dana Farber/Boston Children's Hospital Cancer and Blood Disorder Center, Department of Pediatrics, Harvard Medical School, Boston, MA; Boston Children's Hospital, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA.
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3
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Rajendiran V, Devaraju N, Haddad M, Ravi NS, Panigrahi L, Paul J, Gopalakrishnan C, Wyman S, Ariudainambi K, Mahalingam G, Periyasami Y, Prasad K, George A, Sukumaran D, Gopinathan S, Pai AA, Nakamura Y, Balasubramanian P, Ramalingam R, Thangavel S, Velayudhan SR, Corn JE, Mackay JP, Marepally S, Srivastava A, Crossley M, Mohankumar KM. Base editing of key residues in the BCL11A-XL-specific zinc finger domains derepresses fetal globin expression. Mol Ther 2024; 32:663-677. [PMID: 38273654 PMCID: PMC10928131 DOI: 10.1016/j.ymthe.2024.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 11/03/2023] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
BCL11A-XL directly binds and represses the fetal globin (HBG1/2) gene promoters, using 3 zinc-finger domains (ZnF4, ZnF5, and ZnF6), and is a potential target for β-hemoglobinopathy treatments. Disrupting BCL11A-XL results in derepression of fetal globin and high HbF, but also affects hematopoietic stem and progenitor cell (HSPC) engraftment and erythroid maturation. Intriguingly, neurodevelopmental patients with ZnF domain mutations have elevated HbF with normal hematological parameters. Inspired by this natural phenomenon, we used both CRISPR-Cas9 and base editing at specific ZnF domains and assessed the impacts on HbF production and hematopoietic differentiation. Generating indels in the various ZnF domains by CRISPR-Cas9 prevented the binding of BCL11A-XL to its site in the HBG1/2 promoters and elevated the HbF levels but affected normal hematopoiesis. Far fewer side effects were observed with base editing- for instance, erythroid maturation in vitro was near normal. However, we observed a modest reduction in HSPC engraftment and a complete loss of B cell development in vivo, presumably because current base editing is not capable of precisely recapitulating the mutations found in patients with BCL11A-XL-associated neurodevelopment disorders. Overall, our results reveal that disrupting different ZnF domains has different effects. Disrupting ZnF4 elevated HbF levels significantly while leaving many other erythroid target genes unaffected, and interestingly, disrupting ZnF6 also elevated HbF levels, which was unexpected because this region does not directly interact with the HBG1/2 promoters. This first structure/function analysis of ZnF4-6 provides important insights into the domains of BCL11A-XL that are required to repress fetal globin expression and provide framework for exploring the introduction of natural mutations that may enable the derepression of single gene while leaving other functions unaffected.
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Affiliation(s)
- Vignesh Rajendiran
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala 695 011, India
| | - Nivedhitha Devaraju
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Mahdi Haddad
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Nithin Sam Ravi
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala 695 011, India
| | - Lokesh Panigrahi
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Joshua Paul
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Chandrasekar Gopalakrishnan
- Department of Integrative Biology, School of Bioscience and Technology, Vellore Institute of Technology (VIT, Deemed to be University), Vellore, Tamil Nadu 632014, India
| | - Stacia Wyman
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94704, USA
| | | | - Gokulnath Mahalingam
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India
| | - Yogapriya Periyasami
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India
| | - Kirti Prasad
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Anila George
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala 695 011, India
| | - Dhiyaneshwaran Sukumaran
- Department of Integrative Biology, School of Bioscience and Technology, Vellore Institute of Technology (VIT, Deemed to be University), Vellore, Tamil Nadu 632014, India
| | - Sandhiya Gopinathan
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India
| | - Aswin Anand Pai
- Department of Haematology, Christian Medical College & Hospital, Vellore, Tamil Nadu 632 004, India
| | - Yukio Nakamura
- Cell Engineering Division, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | | | - Rajasekaran Ramalingam
- Department of Integrative Biology, School of Bioscience and Technology, Vellore Institute of Technology (VIT, Deemed to be University), Vellore, Tamil Nadu 632014, India
| | - Saravanabhavan Thangavel
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India
| | - Shaji R Velayudhan
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Department of Haematology, Christian Medical College & Hospital, Vellore, Tamil Nadu 632 004, India
| | - Jacon E Corn
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94704, USA; Institute of Molecular Health Sciences, Department of Biology, Zurich, Switzerland
| | - Joel P Mackay
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Srujan Marepally
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India
| | - Alok Srivastava
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India; Department of Haematology, Christian Medical College & Hospital, Vellore, Tamil Nadu 632 004, India
| | - Merlin Crossley
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Kumarasamypet M Mohankumar
- Centre for Stem Cell Research (a Unit of inStem, Bengaluru), Christian Medical College Campus, Bagayam, Vellore, Tamil Nadu 632002, India.
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4
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Mazzarini M, Cherone J, Nguyen T, Martelli F, Varricchio L, Funnell APW, Papayannopoulou T, Migliaccio AR. The glucocorticoid receptor elicited proliferative response in human erythropoiesis is BCL11A-dependent. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.05.577972. [PMID: 38370646 PMCID: PMC10871295 DOI: 10.1101/2024.02.05.577972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Prior evidence indicates that the erythroid cellular response to glucocorticoids (GC) has developmental specificity, namely, that developmentally more advanced cells that are undergoing or have undergone fetal to adult globin switching are more responsive to GC-induced expansion. To investigate the molecular underpinnings of this, we focused on the major developmental globin regulator BCL11A. We compared: a) levels of expression and nuclear content of BCL11A in adult erythroid cells upon GC stimulation; b) response to GC of CD34+ cells from patients with BCL11A microdeletions and reduced BCL11A expression, and; c) response to GC of two cellular models (HUDEP-2 and adult CD34+ cells) before and after reduction of BCL11A expression by shRNA. We observed that: a) GC-expanded erythroid cells from a large cohort of blood donors displayed amplified expression and nuclear accumulation of BCL11A; b) CD34+ cells from BCL11A microdeletion patients generated fewer erythroid cells when cultured with GC compared to their parents, while the erythroid expansion of the patients was similar to that of their parents in cultures without GC, and; c) adult CD34+ cells and HUDEP-2 cells with shRNA-depleted expression of BCL11A exhibit reduced expansion in response to GC. In addition, RNA-seq profiling of shRNA-BCL11A CD34+ cells cultured with and without GC was similar (very few differentially expressed genes), while GC-specific responses (differential expression of GILZ and of numerous additional genes) were observed only in controls cells with unperturbed BCL11A expression. These data indicate that BCL11A is an important participant of certain aspects of the stress pathway sustained by GC.
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5
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Viennet T, Yin M, Jayaraj A, Kim W, Sun ZYJ, Fujiwara Y, Zhang K, Seruggia D, Seo HS, Dhe-Paganon S, Orkin SH, Arthanari H. Structural Insights into the DNA-Binding Mechanism of BCL11A: The Integral Role of ZnF6. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.576058. [PMID: 38293057 PMCID: PMC10827156 DOI: 10.1101/2024.01.17.576058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
The transcription factor BCL11A is a critical regulator of the switch from fetal hemoglobin (HbF: α 2 γ 2 ) to adult hemoglobin (HbA: α 2 β 2 ) during development. BCL11A binds at a cognate recognition site (TGACCA) in the γ-globin gene promoter and represses its expression. DNA-binding is mediated by a triple zinc finger domain, designated ZnF456. Here, we report comprehensive investigation of ZnF456, leveraging X-ray crystallography and NMR to determine the structures in both the presence and absence of DNA. We delve into the dynamics and mode of interaction with DNA. Moreover, we discovered that the last zinc finger of BCL11A (ZnF6) plays a special role in DNA binding and γ-globin gene repression. Our findings help account for some rare γ-globin gene promoter mutations that perturb BCL11A binding and lead to increased HbF in adults (hereditary persistence of fetal hemoglobin). Comprehending the DNA binding mechanism of BCL11A opens avenues for the strategic, structure-based design of novel therapeutics targeting sickle cell disease and β-thalassemia.
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6
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Zheng G, Orkin SH. Transcriptional Repressor BCL11A in Erythroid Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1459:199-215. [PMID: 39017845 DOI: 10.1007/978-3-031-62731-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
BCL11A, a zinc finger repressor, is a stage-specific transcription factor that controls the switch from fetal (HbF, α2γ2) to adult (HbA, α2β2) hemoglobin in erythroid cells. While BCL11A was known as a factor critical for B-lymphoid cell development, its relationship to erythroid cells and HbF arose through genome-wide association studies (GWAS). Subsequent work validated its role as a silencer of γ-globin gene expression in cultured cells and mice. Erythroid-specific loss of BCL11A rescues the phenotype of engineered sickle cell disease (SCD) mice, thereby suggesting that downregulation of BCL11A expression might be beneficial in patients with SCD and β-thalassemia. Common genetic variation in GWAS resides in an erythroid-specific enhancer within the BCL11A gene that is required for its own expression. CRISPR/Cas9 gene editing of the enhancer revealed a GATA-binding site that confers a large portion of its regulatory function. Disruption of the GATA site leads to robust HbF reactivation. Advancement of a guide RNA targeting the GATA-binding site in clinical trials has recently led to approval of first-in-man use of ex vivo CRISPR editing of hematopoietic stem/progenitor cells (HSPCs) as therapy of SCD and β-thalassemia. Future challenges include expanding access and infrastructure for delivery of genetic therapy to eligible patients, reducing potential toxicity and costs, exploring prospects for in vivo targeting of hematopoietic stem cells (HSCs), and developing small molecule drugs that impair function of BCL11A protein as an alternative option.
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Affiliation(s)
- Ge Zheng
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA
- Harvard Medical School and HHMI, Boston, MA, USA
| | - Stuart H Orkin
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, USA.
- Harvard Medical School and HHMI, Boston, MA, USA.
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7
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Layden HM, Johnson AE, Hiebert SW. Chemical-genetics refines transcription factor regulatory circuits. Trends Cancer 2024; 10:65-75. [PMID: 37722945 PMCID: PMC10840957 DOI: 10.1016/j.trecan.2023.08.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/14/2023] [Accepted: 08/25/2023] [Indexed: 09/20/2023]
Abstract
Transcriptional dysregulation is a key step in oncogenesis, but our understanding of transcriptional control has relied on genetic approaches that are slow and allow for compensation. Chemical-genetic approaches have shortened the time frame for the analysis of transcription factors from days or weeks to minutes. These studies show that while DNA-binding proteins bind to thousands of sites, they are directly required to regulate only a small cadre of genes. Moreover, these transcriptional control networks are far more distinct, with much less overlap and interconnectivity than predicted from DNA binding. The identified direct targets can then be used to dissect the mechanism of action of these factors, which could identify ways to therapeutically manipulate these oncogenic transcriptional control networks.
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Affiliation(s)
- Hillary M Layden
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Anna E Johnson
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Scott W Hiebert
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt-Ingram Cancer Center, Nashville, TN 37027, USA.
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8
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Ibanez V, Vaitkus K, Ruiz MA, Lei Z, Maienschein-Cline M, Arbieva Z, Lavelle D. Effect of the LSD1 inhibitor RN-1 on γ-globin and global gene expression during erythroid differentiation in baboons (Papio anubis). PLoS One 2023; 18:e0289860. [PMID: 38134183 PMCID: PMC10745162 DOI: 10.1371/journal.pone.0289860] [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: 08/08/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
Elevated levels of Fetal Hemoglobin interfere with polymerization of sickle hemoglobin thereby reducing anemia, lessening the severity of symptoms, and increasing life span of patients with sickle cell disease. An affordable, small molecule drug that stimulates HbF expression in vivo would be ideally suited to treat the large numbers of SCD patients that exist worldwide. Our previous work showed that administration of the LSD1 (KDM1A) inhibitor RN-1 to normal baboons increased Fetal Hemoglobin (HbF) and was tolerated over a prolonged treatment period. HbF elevations were associated with changes in epigenetic modifications that included increased levels of H3K4 di-and tri-methyl lysine at the γ-globin promoter. While dramatic effects of the loss of LSD1 on hematopoietic differentiation have been observed in murine LSD1 gene deletion and silencing models, the effect of pharmacological inhibition of LSD1 in vivo on hematopoietic differentiation is unknown. The goal of these experiments was to investigate the in vivo mechanism of action of the LSD1 inhibitor RN-1 by determining its effect on γ-globin expression in highly purified subpopulations of bone marrow erythroid cells enriched for varying stages of erythroid differentiation isolated directly from baboons treated with RN-1 and also by investigating the effect of RN1 on the global transcriptome in a highly purified population of proerythroblasts. Our results show that RN-1 administered to baboons targets an early event during erythroid differentiation responsible for γ-globin repression and increases the expression of a limited number of genes including genes involved in erythroid differentiation such as GATA2, GFi-1B, and LYN.
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Affiliation(s)
- Vinzon Ibanez
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Kestis Vaitkus
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Maria Armila Ruiz
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Zhengdeng Lei
- Research Informatics Core, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Ambry Genetics, Aliso Viejo, California, United States of America
| | - Mark Maienschein-Cline
- Research Informatics Core, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Zarema Arbieva
- Genomics Research Core, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Donald Lavelle
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
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9
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Manieri E, Tie G, Malagola E, Seruggia D, Madha S, Maglieri A, Huang K, Fujiwara Y, Zhang K, Orkin SH, Wang TC, He R, McCarthy N, Shivdasani RA. Role of PDGFRA + cells and a CD55 + PDGFRA Lo fraction in the gastric mesenchymal niche. Nat Commun 2023; 14:7978. [PMID: 38042929 PMCID: PMC10693581 DOI: 10.1038/s41467-023-43619-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 11/15/2023] [Indexed: 12/04/2023] Open
Abstract
PDGFRA-expressing mesenchyme supports intestinal stem cells. Stomach epithelia have related niche dependencies, but their enabling mesenchymal cell populations are unknown, in part because previous studies pooled the gastric antrum and corpus. Our high-resolution imaging, transcriptional profiling, and organoid assays identify regional subpopulations and supportive capacities of purified mouse corpus and antral PDGFRA+ cells. Sub-epithelial PDGFRAHi myofibroblasts are principal sources of BMP ligands and two molecularly distinct pools distribute asymmetrically along antral glands but together fail to support epithelial growth in vitro. In contrast, PDGFRALo CD55+ cells strategically positioned beneath gastric glands promote epithelial expansion in the absence of other cells or factors. This population encompasses a small fraction expressing the BMP antagonist Grem1. Although Grem1+ cell ablation in vivo impairs intestinal stem cells, gastric stem cells are spared, implying that CD55+ cell activity in epithelial self-renewal derives from other subpopulations. Our findings shed light on spatial, molecular, and functional organization of gastric mesenchyme and the spectrum of signaling sources for epithelial support.
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Affiliation(s)
- Elisa Manieri
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Guodong Tie
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Ermanno Malagola
- Division of Digestive and Liver Diseases, Department of Medicine and Irving Cancer Research Center, Columbia University Medical Center, New York, NY, 10032, USA
| | - Davide Seruggia
- Department of Hematology, Boston Children's Hospital, Boston, MA, 02115, USA
- St. Anna Children's Cancer Research Institute, Vienna, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Shariq Madha
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Adrianna Maglieri
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Kun Huang
- Molecular Imaging Core and Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Yuko Fujiwara
- Department of Hematology, Boston Children's Hospital, Boston, MA, 02115, USA
- Howard Hughes Medical Institute, Boston, MA, 02115, USA
| | - Kevin Zhang
- Department of Hematology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Stuart H Orkin
- Department of Hematology, Boston Children's Hospital, Boston, MA, 02115, USA
- Howard Hughes Medical Institute, Boston, MA, 02115, USA
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| | - Timothy C Wang
- Division of Digestive and Liver Diseases, Department of Medicine and Irving Cancer Research Center, Columbia University Medical Center, New York, NY, 10032, USA
| | - Ruiyang He
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Neil McCarthy
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Ramesh A Shivdasani
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA.
- Harvard Stem Cell Institute, Cambridge, MA, 02138, USA.
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10
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Arnold M, Stengel KR. Emerging insights into enhancer biology and function. Transcription 2023; 14:68-87. [PMID: 37312570 PMCID: PMC10353330 DOI: 10.1080/21541264.2023.2222032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/15/2023] Open
Abstract
Cell type-specific gene expression is coordinated by DNA-encoded enhancers and the transcription factors (TFs) that bind to them in a sequence-specific manner. As such, these enhancers and TFs are critical mediators of normal development and altered enhancer or TF function is associated with the development of diseases such as cancer. While initially defined by their ability to activate gene transcription in reporter assays, putative enhancer elements are now frequently defined by their unique chromatin features including DNase hypersensitivity and transposase accessibility, bidirectional enhancer RNA (eRNA) transcription, CpG hypomethylation, high H3K27ac and H3K4me1, sequence-specific transcription factor binding, and co-factor recruitment. Identification of these chromatin features through sequencing-based assays has revolutionized our ability to identify enhancer elements on a genome-wide scale, and genome-wide functional assays are now capitalizing on this information to greatly expand our understanding of how enhancers function to provide spatiotemporal coordination of gene expression programs. Here, we highlight recent technological advances that are providing new insights into the molecular mechanisms by which these critical cis-regulatory elements function in gene control. We pay particular attention to advances in our understanding of enhancer transcription, enhancer-promoter syntax, 3D organization and biomolecular condensates, transcription factor and co-factor dependencies, and the development of genome-wide functional enhancer screens.
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Affiliation(s)
- Mirjam Arnold
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kristy R. Stengel
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Montefiore Einstein Cancer Center, Albert Einstein College of Medicine-Montefiore Health System, Bronx, NY, USA
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, NY, USA
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11
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Finotti A, Gasparello J, Zuccato C, Cosenza LC, Fabbri E, Bianchi N, Gambari R. Effects of Mithramycin on BCL11A Gene Expression and on the Interaction of the BCL11A Transcriptional Complex to γ-Globin Gene Promoter Sequences. Genes (Basel) 2023; 14:1927. [PMID: 37895276 PMCID: PMC10606601 DOI: 10.3390/genes14101927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 09/28/2023] [Accepted: 10/04/2023] [Indexed: 10/29/2023] Open
Abstract
The anticancer drug mithramycin (MTH), has been proposed for drug repurposing after the finding that it is a potent inducer of fetal hemoglobin (HbF) production in erythroid precursor cells (ErPCs) from β-thalassemia patients. In this respect, previously published studies indicate that MTH is very active in inducing increased expression of γ-globin genes in erythroid cells. This is clinically relevant, as it is firmly established that HbF induction is a valuable approach for the therapy of β-thalassemia and for ameliorating the clinical parameters of sickle-cell disease (SCD). Therefore, the identification of MTH biochemical/molecular targets is of great interest. This study is inspired by recent robust evidence indicating that the expression of γ-globin genes is controlled in adult erythroid cells by different transcriptional repressors, including Oct4, MYB, BCL11A, Sp1, KLF3 and others. Among these, BCL11A is very important. In the present paper we report evidence indicating that alterations of BCL11A gene expression and biological functions occur during MTH-mediated erythroid differentiation. Our study demonstrates that one of the mechanisms of action of MTH is a down-regulation of the transcription of the BCL11A gene, while a second mechanism of action is the inhibition of the molecular interactions between the BCL11A complex and specific sequences of the γ-globin gene promoter.
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Affiliation(s)
- Alessia Finotti
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, 44121 Ferrara, Italy; (J.G.); (C.Z.); (L.C.C.); (E.F.); (N.B.)
| | - Jessica Gasparello
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, 44121 Ferrara, Italy; (J.G.); (C.Z.); (L.C.C.); (E.F.); (N.B.)
| | - Cristina Zuccato
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, 44121 Ferrara, Italy; (J.G.); (C.Z.); (L.C.C.); (E.F.); (N.B.)
| | - Lucia Carmela Cosenza
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, 44121 Ferrara, Italy; (J.G.); (C.Z.); (L.C.C.); (E.F.); (N.B.)
| | - Enrica Fabbri
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, 44121 Ferrara, Italy; (J.G.); (C.Z.); (L.C.C.); (E.F.); (N.B.)
| | - Nicoletta Bianchi
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, 44121 Ferrara, Italy; (J.G.); (C.Z.); (L.C.C.); (E.F.); (N.B.)
- Department of Translational Medicine and for Romagna, Ferrara University, 44121 Ferrara, Italy
| | - Roberto Gambari
- Center “Chiara Gemmo and Elio Zago” for the Research on Thalassemia, Ferrara University, 44121 Ferrara, Italy
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12
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Ibanez V, Vaitkus K, Zhang X, Ramasamy J, Rivers AE, Saunthararajah Y, Molokie R, Lavelle D. Combinatorial targeting of epigenome-modifying enzymes with decitabine and RN-1 synergistically increases HbF. Blood Adv 2023; 7:3891-3902. [PMID: 36884303 PMCID: PMC10405201 DOI: 10.1182/bloodadvances.2022009558] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/08/2023] [Accepted: 02/28/2023] [Indexed: 03/09/2023] Open
Abstract
Increased fetal hemoglobin (HbF) levels reduce the symptoms of sickle cell disease (SCD) and increase the lifespan of patients. Because curative strategies for bone marrow transplantation and gene therapy technologies remain unavailable to a large number of patients, the development of a safe and effective pharmacological therapy that increases HbF offers the greatest potential for disease intervention. Although hydroxyurea increases HbF, a substantial proportion of patients fail to demonstrate an adequate response. Pharmacological inhibitors of DNA methyltransferase (DNMT1) and lysine-specific demethylase 1A (LSD1), 2 epigenome-modifying enzymes associated with the multiprotein corepressor complex recruited to the repressed γ-globin gene, are powerful in vivo inducers of HbF. The hematological side effects of these inhibitors limit feasible clinical exposures. We evaluated whether administering these drugs in combination could reduce the dose and/or time of exposure to any single agent to minimize adverse effects, while achieving additive or synergistic increases in HbF. The DNMT1 inhibitor decitabine (0.5 mg/kg per day) and the LSD1 inhibitor RN-1 (0.25 mg/kg per day) administered in combination 2 days per week produced synergistic increases in F-cells, F-reticulocytes, and γ-globin messenger RNA in healthy baboons. Large increases in HbF and F-cells were observed in healthy, nonanemic, and anemic (phlebotomized) baboons. Combinatorial therapy targeting epigenome-modifying enzymes could thus be a useful strategy for producing larger increases in HbF to modify the clinical course of SCD.
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Affiliation(s)
- Vinzon Ibanez
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL
- Research and Development, Jesse Brown VA Medical Center, Chicago, IL
| | - Kestis Vaitkus
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL
- Research and Development, Jesse Brown VA Medical Center, Chicago, IL
| | - Xu Zhang
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL
| | - Jagadeesh Ramasamy
- Department of Pediatrics, University of Illinois at Chicago, Chicago, IL
| | - Angela E. Rivers
- Department of Pediatrics, School of Medicine, University of California at San Francisco Benioff Children’s Hospital Oakland, Oakland, CA
| | - Yogen Saunthararajah
- Department of Hematologic Oncology and Blood Disorders, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH
| | - Robert Molokie
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL
- Research and Development, Jesse Brown VA Medical Center, Chicago, IL
- Department of Pharmaceutical Science, University of Illinois at Chicago, Chicago, IL
| | - Donald Lavelle
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL
- Research and Development, Jesse Brown VA Medical Center, Chicago, IL
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13
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Qin K, Lan X, Huang P, Saari MS, Khandros E, Keller CA, Giardine B, Abdulmalik O, Shi J, Hardison RC, Blobel GA. Molecular basis of polycomb group protein-mediated fetal hemoglobin repression. Blood 2023; 141:2756-2770. [PMID: 36893455 PMCID: PMC10273169 DOI: 10.1182/blood.2022019578] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/15/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
The switch from fetal hemoglobin (HbF) to adult hemoglobin (HbA) is a paradigm for developmental gene expression control with relevance to sickle cell disease and β-thalassemia. Polycomb repressive complex (PRC) proteins regulate this switch, and an inhibitor of PRC2 has entered a clinical trial for HbF activation. Yet, how PRC complexes function in this process, their target genes, and relevant subunit composition are unknown. Here, we identified the PRC1 subunit BMI1 as a novel HbF repressor. We uncovered the RNA binding proteins LIN28B, IGF2BP1, and IGF2BP3 genes as direct BMI1 targets, and demonstrate that they account for the entirety of BMI1's effect on HbF regulation. BMI1 functions as part of the canonical PRC1 (cPRC1) subcomplex as revealed by the physical and functional dissection of BMI1 protein partners. Lastly, we demonstrate that BMI1/cPRC1 acts in concert with PRC2 to repress HbF through the same target genes. Our study illuminates how PRC silences HbF, highlighting an epigenetic mechanism involved in hemoglobin switching.
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Affiliation(s)
- Kunhua Qin
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Xianjiang Lan
- Department of Systems Biology for Medicine, School of Basic Medical Sciences, Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Peng Huang
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Megan S. Saari
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Eugene Khandros
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Cheryl A. Keller
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, State College, PA
| | - Belinda Giardine
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, State College, PA
| | - Osheiza Abdulmalik
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Junwei Shi
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ross C. Hardison
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, State College, PA
| | - Gerd A. Blobel
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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14
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Harada T, Perez MW, Kalfon J, Braes FD, Batley R, Eagle K, Nabet B, Leifer B, Kruell J, Paralkar VR, Stegmaier K, Koehler AN, Orkin SH, Pimkin M. Rapid-kinetics degron benchmarking reveals off-target activities and mixed agonism-antagonism of MYB inhibitors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.07.536032. [PMID: 37066194 PMCID: PMC10104119 DOI: 10.1101/2023.04.07.536032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Attenuating aberrant transcriptional circuits holds great promise for the treatment of numerous diseases, including cancer. However, development of transcriptional inhibitors is hampered by the lack of a generally accepted functional cellular readout to characterize their target specificity and on-target activity. We benchmarked the direct gene-regulatory signatures of six agents reported as inhibitors of the oncogenic transcription factor MYB against targeted MYB degradation in a nascent transcriptomics assay. The inhibitors demonstrated partial specificity for MYB target genes but displayed significant off-target activity. Unexpectedly, the inhibitors displayed bimodal on-target effects, acting as mixed agonists-antagonists. Our data uncover unforeseen agonist effects of small molecules originally developed as TF inhibitors and argue that rapid-kinetics benchmarking against degron models should be used for functional characterization of transcriptional modulators.
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Affiliation(s)
- Taku Harada
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
| | - Monika W. Perez
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
| | - Jérémie Kalfon
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, 02142, USA
| | - Flora Dievenich Braes
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
| | - Rashad Batley
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
| | - Kenneth Eagle
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
- Ken Eagle Consulting, Houston, TX, 77494, USA
| | - Behnam Nabet
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA, 98109, USA
| | - Becky Leifer
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Jasmin Kruell
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Vikram R. Paralkar
- Division of Hematology/Oncology, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kimberly Stegmaier
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, 02142, USA
| | - Angela N. Koehler
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, 02142, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Stuart H. Orkin
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
- Howard Hughes Medical Institute, Boston, MA, 02215, USA
| | - Maxim Pimkin
- Cancer and Blood Disorders Center, Dana-Farber Cancer Institute and Boston Children’s Hospital, Harvard Medical School, Boston, MA, 02215, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, 02142, USA
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15
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Manieri E, Tie G, Seruggia D, Madha S, Maglieri A, Huang K, Fujiwara Y, Zhang K, Orkin SH, He R, McCarthy N, Shivdasani RA. Defining the structure, signals, and cellular elements of the gastric mesenchymal niche. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.11.527728. [PMID: 36798304 PMCID: PMC9934611 DOI: 10.1101/2023.02.11.527728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
PDGFRA-expressing mesenchyme provides a niche for intestinal stem cells. Corresponding compartments are unknown in the stomach, where corpus and antral glandular epithelia have similar niche dependencies but are structurally distinct from the intestine and from each other. Previous studies considered antrum and corpus as a whole and did not assess niche functions. Using high-resolution imaging and sequencing, we identify regional subpopulations and niche properties of purified mouse corpus and antral PDGFRA + cells. PDGFRA Hi sub-epithelial myofibroblasts are principal sources of BMP ligands in both gastric segments; two molecularly distinct groups distribute asymmetrically along antral glands but together fail to support epithelial organoids in vitro . In contrast, strategically positioned PDGFRA Lo cells that express CD55 enable corpus and antral organoid growth in the absence of other cellular or soluble factors. Our study provides detailed insights into spatial, molecular, and functional organization of gastric mesenchyme and the spectrum of signaling sources for stem cell support.
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16
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Mehta S, Buyanbat A, Orkin S, Nabet B. High-efficiency knock-in of degradable tags (dTAG) at endogenous loci in cell lines. Methods Enzymol 2023; 681:1-22. [PMID: 36764753 DOI: 10.1016/bs.mie.2022.08.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The dTAG system is a versatile strategy for tunable control of protein abundance and facilitates the time-resolved assessment of disease-associated protein function. A "co-opted" fusion-based degron peptide, the "dTAG" facilitates the study of endogenous protein function when knocked-in at the endogenous genetic loci of proteins of interest. We combine CRISPR/Cas9 mediated induction of double-strand breaks (DSB) with the delivery of a single-stranded DNA HDR-donor-template via crude preparations of recombinant adeno-associated virus (rAAV). Our approach to knock-in of large (1-2kb) DNA fragments via crude-rAAV mediated HDR donor delivery is rapid and inexpensive. It facilitates genetic modification of a variety of human as well as mouse cell lines at high efficiency and precision.
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Affiliation(s)
- Stuti Mehta
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, United States
| | - Altantsetseg Buyanbat
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, United States
| | - Stuart Orkin
- Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA, United States
| | - Behnam Nabet
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA, United States.
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17
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Yin M, Izadi M, Tenglin K, Viennet T, Zhai L, Zheng G, Arthanari H, Dassama LMK, Orkin SH. Evolution of nanobodies specific for BCL11A. Proc Natl Acad Sci U S A 2023; 120:e2218959120. [PMID: 36626555 PMCID: PMC9933118 DOI: 10.1073/pnas.2218959120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Transcription factors (TFs) control numerous genes that are directly relevant to many human disorders. However, developing specific reagents targeting TFs within intact cells is challenging due to the presence of highly disordered regions within these proteins. Intracellular antibodies offer opportunities to probe protein function and validate therapeutic targets. Here, we describe the optimization of nanobodies specific for BCL11A, a validated target for the treatment of hemoglobin disorders. We obtained first-generation nanobodies directed to a region of BCL11A comprising zinc fingers 4 to 6 (ZF456) from a synthetic yeast surface display library, and employed error-prone mutagenesis, structural determination, and molecular modeling to enhance binding affinity. Engineered nanobodies recognized ZF6 and mediated targeted protein degradation (TPD) of BCL11A protein in erythroid cells, leading to the anticipated reactivation of fetal hemoglobin (HbF) expression. Evolved nanobodies distinguished BCL11A from its close paralog BCL11B, which shares an identical DNA-binding specificity. Given the ease of manipulation of nanobodies and their exquisite specificity, nanobody-mediated TPD of TFs should be suitable for dissecting regulatory relationships of TFs and gene targets and validating therapeutic potential of proteins of interest.
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Affiliation(s)
- Maolu Yin
- Dana Farber Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA02115
- HHMI, Harvard Medical School, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
| | - Manizheh Izadi
- Dana Farber Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA02115
- HHMI, Harvard Medical School, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
| | - Karin Tenglin
- Dana Farber Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA02115
- HHMI, Harvard Medical School, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
| | - Thibault Viennet
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, MA02115
- Department of Cancer Biology, Dana-Farber Cancer Institute, MA02215
| | - Liting Zhai
- Department of Chemistry and Sarafan ChEM-H, Stanford University, Stanford, CA94305
| | - Ge Zheng
- Dana Farber Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA02115
- HHMI, Harvard Medical School, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, MA02115
- Department of Cancer Biology, Dana-Farber Cancer Institute, MA02215
| | - Laura M. K. Dassama
- Department of Chemistry and Sarafan ChEM-H, Stanford University, Stanford, CA94305
| | - Stuart H. Orkin
- Dana Farber Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA02115
- HHMI, Harvard Medical School, Boston, MA02115
- Department of Pediatrics, Harvard Medical School, Boston, MA02115
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