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1.
Physiol Rev ; 102(2): 859-892, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34486392

RESUMO

Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system (CNS). The ability of each of these globins to interact with molecular oxygen (O2) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extraerythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin, are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in nonvascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the CNS and the peripheral nervous system. Brain and CNS neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and thus tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scavenging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology, with a focus on NO biology, and offer perspectives for future study of these functions.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Citoglobina/metabolismo , Células Endoteliais/metabolismo , Globinas/metabolismo , Animais , Humanos , Mioglobina/metabolismo , Neuroglobina/metabolismo
2.
Mol Cell ; 81(2): 239-254.e8, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33301730

RESUMO

Metazoan transcription factors typically regulate large numbers of genes. Here we identify via a CRISPR-Cas9 genetic screen ZNF410, a pentadactyl DNA-binding protein that in human erythroid cells directly activates only a single gene, the NuRD component CHD4. Specificity is conveyed by two highly evolutionarily conserved clusters of ZNF410 binding sites near the CHD4 gene with no counterparts elsewhere in the genome. Loss of ZNF410 in adult-type human erythroid cell culture systems and xenotransplantation settings diminishes CHD4 levels and derepresses the fetal hemoglobin genes. While previously known to be silenced by CHD4, the fetal globin genes are exposed here as among the most sensitive to reduced CHD4 levels.. In vitro DNA binding assays and crystallographic studies reveal the ZNF410-DNA binding mode. ZNF410 is a remarkably selective transcriptional activator in erythroid cells, and its perturbation might offer new opportunities for treatment of hemoglobinopathies.


Assuntos
DNA/genética , Células Precursoras Eritroides/metabolismo , Hemoglobina Fetal/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Fatores de Transcrição/genética , Animais , Sítios de Ligação , Células COS , Sistemas CRISPR-Cas , Chlorocebus aethiops , DNA/metabolismo , Células Precursoras Eritroides/citologia , Células Precursoras Eritroides/transplante , Sangue Fetal/citologia , Sangue Fetal/metabolismo , Hemoglobina Fetal/metabolismo , Feto , Edição de Genes , Células HEK293 , Xenoenxertos , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/química , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Camundongos , Modelos Moleculares , Células-Tronco Embrionárias Murinas/citologia , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Ativação Transcricional
3.
Nature ; 610(7933): 783-790, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36224385

RESUMO

Around birth, globin expression in human red blood cells (RBCs) shifts from γ-globin to ß-globin, which results in fetal haemoglobin (HbF, α2γ2) being gradually replaced by adult haemoglobin (HbA, α2ß2)1. This process has motivated the development of innovative approaches to treat sickle cell disease and ß-thalassaemia by increasing HbF levels in postnatal RBCs2. Here we provide therapeutically relevant insights into globin gene switching obtained through a CRISPR-Cas9 screen for ubiquitin-proteasome components that regulate HbF expression. In RBC precursors, depletion of the von Hippel-Lindau (VHL) E3 ubiquitin ligase stabilized its ubiquitination target, hypoxia-inducible factor 1α (HIF1α)3,4, to induce γ-globin gene transcription. Mechanistically, HIF1α-HIF1ß heterodimers bound cognate DNA elements in BGLT3, a long noncoding RNA gene located 2.7 kb downstream of the tandem γ-globin genes HBG1 and HBG2. This was followed by the recruitment of transcriptional activators, chromatin opening and increased long-range interactions between the γ-globin genes and their upstream enhancer. Similar induction of HbF occurred with hypoxia or with inhibition of prolyl hydroxylase domain enzymes that target HIF1α for ubiquitination by the VHL E3 ubiquitin ligase. Our findings link globin gene regulation with canonical hypoxia adaptation, provide a mechanism for HbF induction during stress erythropoiesis and suggest a new therapeutic approach for ß-haemoglobinopathies.


Assuntos
gama-Globinas , Humanos , Cromatina , Hemoglobina Fetal/biossíntese , Hemoglobina Fetal/genética , gama-Globinas/biossíntese , gama-Globinas/genética , Hipóxia/genética , Prolil Hidroxilases/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Longo não Codificante , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genética , Eritropoese
4.
Genome Res ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951027

RESUMO

Knowledge of locations and activities of cis-regulatory elements (CREs) is needed to decipher basic mechanisms of gene regulation and to understand the impact of genetic variants on complex traits. Previous studies identified candidate CREs (cCREs) using epigenetic features in one species, making comparisons difficult between species. In contrast, we conducted an interspecies study defining epigenetic states and identifying cCREs in blood cell types to generate regulatory maps that are comparable between species, using integrative modeling of eight epigenetic features jointly in human and mouse in our Validated Systematic Integration (VISION) Project. The resulting catalogs of cCREs are useful resources for further studies of gene regulation in blood cells, indicated by high overlap with known functional elements and strong enrichment for human genetic variants associated with blood cell phenotypes. The contribution of each epigenetic state in cCREs to gene regulation, inferred from a multivariate regression, was used to estimate epigenetic state Regulatory Potential (esRP) scores for each cCRE in each cell type, which were used to categorize dynamic changes in cCREs. Groups of cCREs displaying similar patterns of regulatory activity in human and mouse cell types, obtained by joint clustering on esRP scores, harbored distinctive transcription factor binding motifs that were similar between species. An interspecies comparison of cCREs revealed both conserved and species-specific patterns of epigenetic evolution. Finally, we showed that comparisons of the epigenetic landscape between species can reveal elements with similar roles in regulation, even in the absence of genomic sequence alignment.

5.
Nature ; 595(7866): 295-302, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34079130

RESUMO

Sickle cell disease (SCD) is caused by a mutation in the ß-globin gene HBB1. We used a custom adenine base editor (ABE8e-NRCH)2,3 to convert the SCD allele (HBBS) into Makassar ß-globin (HBBG), a non-pathogenic variant4,5. Ex vivo delivery of mRNA encoding the base editor with a targeting guide RNA into haematopoietic stem and progenitor cells (HSPCs) from patients with SCD resulted in 80% conversion of HBBS to HBBG. Sixteen weeks after transplantation of edited human HSPCs into immunodeficient mice, the frequency of HBBG was 68% and hypoxia-induced sickling of bone marrow reticulocytes had decreased fivefold, indicating durable gene editing. To assess the physiological effects of HBBS base editing, we delivered ABE8e-NRCH and guide RNA into HSPCs from a humanized SCD mouse6 and then transplanted these cells into irradiated mice. After sixteen weeks, Makassar ß-globin represented 79% of ß-globin protein in blood, and hypoxia-induced sickling was reduced threefold. Mice that received base-edited HSPCs showed near-normal haematological parameters and reduced splenic pathology compared to mice that received unedited cells. Secondary transplantation of edited bone marrow confirmed that the gene editing was durable in long-term haematopoietic stem cells and showed that HBBS-to-HBBG editing of 20% or more is sufficient for phenotypic rescue. Base editing of human HSPCs avoided the p53 activation and larger deletions that have been observed following Cas9 nuclease treatment. These findings point towards a one-time autologous treatment for SCD that eliminates pathogenic HBBS, generates benign HBBG, and minimizes the undesired consequences of double-strand DNA breaks.


Assuntos
Adenina/metabolismo , Anemia Falciforme/genética , Anemia Falciforme/terapia , Edição de Genes , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/metabolismo , Globinas beta/genética , Animais , Antígenos CD34/metabolismo , Proteína 9 Associada à CRISPR/metabolismo , Modelos Animais de Doenças , Feminino , Terapia Genética , Genoma Humano/genética , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/patologia , Humanos , Masculino , Camundongos
6.
Blood ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38848504

RESUMO

Red blood cells (RBC) express high levels of hemoglobin A tetramer (HbA, 22) to facilitate oxygen (O2) transport. Hemoglobin and related proteins are also expressed at lower levels in other tissues across the animal kingdom. Physiological functions for most non-erythroid globins likely derive from their ability to catalyze reduction-oxidation (redox) reactions via electron transfer through heme-associated iron. An interesting example is illustrated by the recent discovery that -globin without -globin is expressed in some arteriolar endothelial cells (ECs). -Globin binds EC nitric oxide synthase (eNOS) and degrades its enzymatic product nitric oxide (NO), a potent vasodilator. Thus, depletion of -globin in ECs or inhibition of its association with eNOS causes arteriolar relaxation and lowering of blood pressure in mice. Some of these findings have been replicated in isolated human blood vessels and genetic studies are tractable in populations where -thalassemia alleles are prevalent. Two small studies identified associations between loss of -genes in humans and NO-regulated vascular responses elicited by local hypoxia-induced blood flow or thermal stimulation. In a few larger population-based studies, no associations were detected between loss of -globin genes and blood pressure, ischemic stroke or pulmonary hypertension. In contrast, a significant positive association between -globin gene copy number and kidney disease was detected in an African American cohort. Further studies are required to define comprehensively the expression of -globin and related globin proteins in different vascular beds and ascertain their overall impact on normal and pathological vascular physiology.

7.
Trends Genet ; 38(12): 1284-1298, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35934593

RESUMO

Sickle cell disease (SCD) is a common genetic blood disorder associated with acute and chronic pain, progressive multiorgan damage, and early mortality. Recent advances in technologies to manipulate the human genome, a century of research and the development of techniques enabling the isolation, efficient genetic modification, and reimplantation of autologous patient hematopoietic stem cells (HSCs), mean that curing most patients with SCD could soon be a reality in wealthy countries. In parallel, ongoing research is pursuing more facile treatments, such as in-vivo-delivered genetic therapies and new drugs that can eventually be administered in low- and middle-income countries where most SCD patients reside.


Assuntos
Anemia Falciforme , Transplante de Células-Tronco Hematopoéticas , Humanos , Anemia Falciforme/genética , Anemia Falciforme/terapia , Edição de Genes/métodos , Células-Tronco Hematopoéticas , Terapia Genética
8.
Blood ; 142(10): 918-932, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37339583

RESUMO

Most cells can eliminate unstable or misfolded proteins through quality control mechanisms. In the inherited red blood cell disorder ß-thalassemia, mutations in the ß-globin gene (HBB) lead to a reduction in the corresponding protein and the accumulation of cytotoxic free α-globin, which causes maturation arrest and apoptosis of erythroid precursors and reductions in the lifespan of circulating red blood cells. We showed previously that excess α-globin is eliminated by Unc-51-like autophagy activating kinase 1 (ULK1)-dependent autophagy and that stimulating this pathway by systemic mammalian target of rapamycin complex 1 (mTORC1) inhibition alleviates ß-thalassemia pathologies. We show here that disrupting the bicistronic microRNA gene miR-144/451 alleviates ß-thalassemia by reducing mTORC1 activity and stimulating ULK1-mediated autophagy of free α-globin through 2 mechanisms. Loss of miR-451 upregulated its target messenger RNA, Cab39, which encodes a cofactor for LKB1, a serine-threonine kinase that phosphorylates and activates the central metabolic sensor adenosine monophosphate-activated protein kinase (AMPK). The resultant enhancement of LKB1 activity stimulated AMPK and its downstream effects, including repression of mTORC1 and direct activation of ULK1. In addition, loss of miR-144/451 inhibited the expression of erythroblast transferrin receptor 1, causing intracellular iron restriction, which has been shown to inhibit mTORC1, reduce free α-globin precipitates, and improve hematological indices in ß-thalassemia. The beneficial effects of miR-144/451 loss in ß-thalassemia were inhibited by the disruption of Cab39 or Ulk1 genes. Together, our findings link the severity of ß-thalassemia to a highly expressed erythroid microRNA locus and a fundamental, metabolically regulated protein quality control pathway that is amenable to therapeutic manipulation.


Assuntos
MicroRNAs , Talassemia beta , Humanos , Talassemia beta/terapia , Proteínas Quinases Ativadas por AMP/metabolismo , alfa-Globinas , Autofagia/genética , MicroRNAs/genética , Alvo Mecanístico do Complexo 1 de Rapamicina , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética
9.
Mol Ther ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39086133

RESUMO

Sickle cell disease (SCD) is a common, severe genetic blood disorder. Current pharmacotherapies are partially effective and allogeneic hematopoietic stem cell transplantation (HSCT) is associated with immune toxicities. Genome editing of patient hematopoietic stem cells (HSCs) to reactivate fetal hemoglobin (HbF) in erythroid progeny offers an alternative potentially curative approach to treat SCD. Although the FDA released guidelines for evaluating genome editing risks, it remains unclear how best to approach pre-clinical assessment of genome-edited cell products. Here we describe rigorous pre-clinical development of a therapeutic γ-globin gene promoter editing strategy that supported an investigational new drug (IND) application cleared by the FDA. We compared γ-globin promoter and BCL11A enhancer targets, identified a potent HbF-inducing lead candidate, and tested our approach in mobilized CD34+ HSPCs from SCD patients. We observed efficient editing, HbF induction to predicted therapeutic levels, and reduced sickling. With single-cell analyses, we defined the heterogeneity of HbF induction and HBG1/HBG2 transcription. With CHANGE-seq for sensitive and unbiased off-target discovery followed by targeted sequencing, we did not detect off-target activity in edited HSPCs. Our study provides a blueprint for translating new ex vivo HSC genome editing strategies towards clinical trials for treating SCD and other blood disorders.

10.
Curr Opin Hematol ; 31(3): 104-114, 2024 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-38359264

RESUMO

PURPOSE OF REVIEW: Gene therapy for sickle cell disease (SCD) is advancing rapidly, with two transformative products recently approved by the US Food and Drug Administration and numerous others under study. All current gene therapy protocols require ex vivo modification of autologous hematopoietic stem cells (HSCs). However, several SCD-related problems impair HSC collection, including a stressed and damaged bone marrow, potential cytotoxicity by the major therapeutic drug hydroxyurea, and inability to use granulocyte colony stimulating factor, which can precipitate severe vaso-occlusive events. RECENT FINDINGS: Peripheral blood mobilization of HSCs using the CXCR4 antagonist plerixafor followed by apheresis collection was recently shown to be safe and effective for most SCD patients and is the current strategy for mobilizing HSCs. However, exceptionally large numbers of HSCs are required to manufacture an adequate cellular product, responses to plerixafor are variable, and most patients require multiple mobilization cycles, increasing the risk for adverse events. For some, gene therapy is prohibited by the failure to obtain adequate numbers of HSCs. SUMMARY: Here we review the current knowledge on HSC collection from individuals with SCD and potential improvements that may enhance the safety, efficacy, and availability of gene therapy for this disorder.


Assuntos
Anemia Falciforme , Transplante de Células-Tronco Hematopoéticas , Compostos Heterocíclicos , Humanos , Mobilização de Células-Tronco Hematopoéticas/métodos , Compostos Heterocíclicos/uso terapêutico , Compostos Heterocíclicos/efeitos adversos , Células-Tronco Hematopoéticas/metabolismo , Anemia Falciforme/genética , Anemia Falciforme/terapia , Fator Estimulador de Colônias de Granulócitos , Terapia Genética/efeitos adversos
11.
Blood ; 139(14): 2107-2118, 2022 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-35090172

RESUMO

The benign condition hereditary persistence of fetal hemoglobin (HPFH) is known to ameliorate symptoms of co-inherited ß-hemoglobinopathies, such as sickle cell disease and ß-thalassemia. The condition is sometimes associated with point mutations in the fetal globin promoters that disrupt the binding of the repressors BCL11A or ZBTB7A/LRF, which have been extensively studied. HPFH is also associated with a range of deletions within the ß-globin locus that all reside downstream of the fetal HBG2 gene. These deletional forms of HPFH are poorly understood and are the focus of this study. Numerous different mechanisms have been proposed to explain how downstream deletions can boost the expression of the fetal globin genes, including the deletion of silencer elements, of genes encoding noncoding RNA, and bringing downstream enhancer elements into proximity with the fetal globin gene promoters. Here we systematically analyze the deletions associated with both HPFH and a related condition known as δß-thalassemia and propose a unifying mechanism. In all cases where fetal globin is upregulated, the proximal adult ß-globin (HBB) promoter is deleted. We use clustered regularly interspaced short palindromic repeats-mediated gene editing to delete or disrupt elements within the promoter and find that virtually all mutations that reduce ΗΒΒ promoter activity result in elevated fetal globin expression. These results fit with previous models where the fetal and adult globin genes compete for the distal locus control region and suggest that targeting the ΗΒΒ promoter might be explored to elevate fetal globin and reduce sickle globin expression as a treatment of ß-hemoglobinopathies.


Assuntos
Globinas , Talassemia beta , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , Expressão Gênica , Globinas/metabolismo , Humanos , Fatores de Transcrição/genética , Globinas beta/genética , Globinas beta/metabolismo , Talassemia beta/genética , Talassemia beta/terapia
12.
Mol Cell ; 62(1): 104-10, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-27041223

RESUMO

Long non-coding (lnc) RNAs can regulate gene expression and protein functions. However, the proportion of lncRNAs with biological activities among the thousands expressed in mammalian cells is controversial. We studied Lockd (lncRNA downstream of Cdkn1b), a 434-nt polyadenylated lncRNA originating 4 kb 3' to the Cdkn1b gene. Deletion of the 25-kb Lockd locus reduced Cdkn1b transcription by approximately 70% in an erythroid cell line. In contrast, homozygous insertion of a polyadenylation cassette 80 bp downstream of the Lockd transcription start site reduced the entire lncRNA transcript level by >90% with no effect on Cdkn1b transcription. The Lockd promoter contains a DNase-hypersensitive site, binds numerous transcription factors, and physically associates with the Cdkn1b promoter in chromosomal conformation capture studies. Therefore, the Lockd gene positively regulates Cdkn1b transcription through an enhancer-like cis element, whereas the lncRNA itself is dispensable, which may be the case for other lncRNAs.


Assuntos
Inibidor de Quinase Dependente de Ciclina p27/genética , Elementos Facilitadores Genéticos , RNA Longo não Codificante/genética , Animais , Linhagem Celular , Regulação da Expressão Gênica , Camundongos , Poli A/metabolismo , Regiões Promotoras Genéticas , Transcrição Gênica
13.
J Nerv Ment Dis ; 212(1): 16-27, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37874984

RESUMO

ABSTRACT: A Cultural Formulation Interview (CFI) field trial in India, widely reported racist violence in the United States, and casteist and religious communal conflicts in India highlighted inattention to structural issues affecting mental health problems in the Outline for Cultural Formulation (OCF) and the CFI in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition). Consequently, we revised the OCF as a sociocultural formulation (SCF) to better consider structures of society and culture. We studied and compared clinicians' ratings of SCF case formulations from a constructed assessment instrument (SCF Interview [SCFI]) and the CFI. Socio-cultural formulations from SCFI interviews were rated higher for details of societal structural impact, and overall interrater agreement was better. CFI interviews were rated higher for clinical rapport. Revision of the CFI should enhance consideration of structural issues and incorporate them in SCFs that better integrate assessment process and case formulation content. The need to acknowledge structural sources of mental health problems is clear, and our study indicates how a sociocultural framework may be used for that.


Assuntos
Transtornos Mentais , Humanos , Entrevista Psicológica , Transtornos Mentais/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Índia , Violência
14.
Genome Res ; 30(3): 472-484, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32132109

RESUMO

Thousands of epigenomic data sets have been generated in the past decade, but it is difficult for researchers to effectively use all the data relevant to their projects. Systematic integrative analysis can help meet this need, and the VISION project was established for validated systematic integration of epigenomic data in hematopoiesis. Here, we systematically integrated extensive data recording epigenetic features and transcriptomes from many sources, including individual laboratories and consortia, to produce a comprehensive view of the regulatory landscape of differentiating hematopoietic cell types in mouse. By using IDEAS as our integrative and discriminative epigenome annotation system, we identified and assigned epigenetic states simultaneously along chromosomes and across cell types, precisely and comprehensively. Combining nuclease accessibility and epigenetic states produced a set of more than 200,000 candidate cis-regulatory elements (cCREs) that efficiently capture enhancers and promoters. The transitions in epigenetic states of these cCREs across cell types provided insights into mechanisms of regulation, including decreases in numbers of active cCREs during differentiation of most lineages, transitions from poised to active or inactive states, and shifts in nuclease accessibility of CTCF-bound elements. Regression modeling of epigenetic states at cCREs and gene expression produced a versatile resource to improve selection of cCREs potentially regulating target genes. These resources are available from our VISION website to aid research in genomics and hematopoiesis.


Assuntos
Epigênese Genética , Hematopoese/genética , Células-Tronco Hematopoéticas/metabolismo , Animais , Camundongos , Elementos Reguladores de Transcrição , Transcriptoma
15.
Blood ; 137(10): 1327-1339, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33512425

RESUMO

While constitutive CCCTC-binding factor (CTCF)-binding sites are needed to maintain relatively invariant chromatin structures, such as topologically associating domains, the precise roles of CTCF to control cell-type-specific transcriptional regulation remain poorly explored. We examined CTCF occupancy in different types of primary blood cells derived from the same donor to elucidate a new role for CTCF in gene regulation during blood cell development. We identified dynamic, cell-type-specific binding sites for CTCF that colocalize with lineage-specific transcription factors. These dynamic sites are enriched for single-nucleotide polymorphisms that are associated with blood cell traits in different linages, and they coincide with the key regulatory elements governing hematopoiesis. CRISPR-Cas9-based perturbation experiments demonstrated that these dynamic CTCF-binding sites play a critical role in red blood cell development. Furthermore, precise deletion of CTCF-binding motifs in dynamic sites abolished interactions of erythroid genes, such as RBM38, with their associated enhancers and led to abnormal erythropoiesis. These results suggest a novel, cell-type-specific function for CTCF in which it may serve to facilitate interaction of distal regulatory emblements with target promoters. Our study of the dynamic, cell-type-specific binding and function of CTCF provides new insights into transcriptional regulation during hematopoiesis.


Assuntos
Fator de Ligação a CCCTC/metabolismo , Eritropoese , Elementos Reguladores de Transcrição , Sítios de Ligação , Linhagem Celular , Células Cultivadas , Elementos Facilitadores Genéticos , Células Eritroides/citologia , Células Eritroides/metabolismo , Humanos , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ativação Transcricional
16.
Blood ; 137(2): 155-167, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33156908

RESUMO

The histone mark H3K27me3 and its reader/writer polycomb repressive complex 2 (PRC2) mediate widespread transcriptional repression in stem and progenitor cells. Mechanisms that regulate this activity are critical for hematopoietic development but are poorly understood. Here we show that the E3 ubiquitin ligase F-box only protein 11 (FBXO11) relieves PRC2-mediated repression during erythroid maturation by targeting its newly identified substrate bromo adjacent homology domain-containing 1 (BAHD1), an H3K27me3 reader that recruits transcriptional corepressors. Erythroblasts lacking FBXO11 are developmentally delayed, with reduced expression of maturation-associated genes, most of which harbor bivalent histone marks at their promoters. In FBXO11-/- erythroblasts, these gene promoters bind BAHD1 and fail to recruit the erythroid transcription factor GATA1. The BAHD1 complex interacts physically with PRC2, and depletion of either component restores FBXO11-deficient erythroid gene expression. Our studies identify BAHD1 as a novel effector of PRC2-mediated repression and reveal how a single E3 ubiquitin ligase eliminates PRC2 repression at many developmentally poised bivalent genes during erythropoiesis.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Eritropoese/fisiologia , Proteínas F-Box/metabolismo , Regulação da Expressão Gênica/fisiologia , Complexo Repressor Polycomb 2/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Linhagem Celular , Eritroblastos/metabolismo , Humanos , Proteólise
17.
Br J Haematol ; 198(4): 740-744, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35737751

RESUMO

We adjusted haematopoietic stem and progenitor cell (HSPC) apheresis collection from patients with sickle cell disease (SCD) by targeting deep buffy coat collection using medium or low collection preference (CP), and by increasing anticoagulant-citrate-dextrose-solution A dosage. In 43 HSPC collections from plerixafor-mobilized adult patients with SCD, we increased the collection efficiency to 35.79% using medium CP and 82.23% using low CP. Deep buffy coat collection increased red blood cell contamination of the HSPC product, the product haematocrit was 4.7% with medium CP and 6.4% with low CP. These adjustments were well-tolerated and allowed efficient HSPC collection from SCD patients.


Assuntos
Anemia Falciforme , Remoção de Componentes Sanguíneos , Compostos Heterocíclicos , Adulto , Anemia Falciforme/terapia , Benzilaminas , Ciclamos , Mobilização de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Humanos , Leucaférese
18.
N Engl J Med ; 380(16): 1525-1534, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30995372

RESUMO

BACKGROUND: Allogeneic hematopoietic stem-cell transplantation for X-linked severe combined immunodeficiency (SCID-X1) often fails to reconstitute immunity associated with T cells, B cells, and natural killer (NK) cells when matched sibling donors are unavailable unless high-dose chemotherapy is given. In previous studies, autologous gene therapy with γ-retroviral vectors failed to reconstitute B-cell and NK-cell immunity and was complicated by vector-related leukemia. METHODS: We performed a dual-center, phase 1-2 safety and efficacy study of a lentiviral vector to transfer IL2RG complementary DNA to bone marrow stem cells after low-exposure, targeted busulfan conditioning in eight infants with newly diagnosed SCID-X1. RESULTS: Eight infants with SCID-X1 were followed for a median of 16.4 months. Bone marrow harvest, busulfan conditioning, and cell infusion had no unexpected side effects. In seven infants, the numbers of CD3+, CD4+, and naive CD4+ T cells and NK cells normalized by 3 to 4 months after infusion and were accompanied by vector marking in T cells, B cells, NK cells, myeloid cells, and bone marrow progenitors. The eighth infant had an insufficient T-cell count initially, but T cells developed in this infant after a boost of gene-corrected cells without busulfan conditioning. Previous infections cleared in all infants, and all continued to grow normally. IgM levels normalized in seven of the eight infants, of whom four discontinued intravenous immune globulin supplementation; three of these four infants had a response to vaccines. Vector insertion-site analysis was performed in seven infants and showed polyclonal patterns without clonal dominance in all seven. CONCLUSIONS: Lentiviral vector gene therapy combined with low-exposure, targeted busulfan conditioning in infants with newly diagnosed SCID-X1 had low-grade acute toxic effects and resulted in multilineage engraftment of transduced cells, reconstitution of functional T cells and B cells, and normalization of NK-cell counts during a median follow-up of 16 months. (Funded by the American Lebanese Syrian Associated Charities and others; LVXSCID-ND ClinicalTrials.gov number, NCT01512888.).


Assuntos
Bussulfano/administração & dosagem , Terapia Genética , Vetores Genéticos , Subunidade gama Comum de Receptores de Interleucina/genética , Lentivirus , Condicionamento Pré-Transplante , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/terapia , Antígenos de Diferenciação de Linfócitos T/sangue , Linfócitos B/fisiologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunoglobulina M/sangue , Lactente , Células Matadoras Naturais , Contagem de Linfócitos , Masculino , Linfócitos T , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia
19.
Allergy Asthma Proc ; 43(3): 226-233, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35524355

RESUMO

Background: Peanut component tests (PCT) have become important in the evaluation of peanut allergy. There remains a paucity of research across the United States in investigating the utility of PCT in clinical practice in conjunction with current standards of care. Objective: The primary aims were to evaluate the performance and sensitization patterns of PCT in clinical practice when first available at our institution. Methods: We performed a retrospective chart review of 184 children with PCT and oral food challenge (OFC) results between 2012 and 2017. Simple logistic regression models assessed the associations between PCT and OFC outcomes. Receiver operator characteristic curves were constructed, and a predicted probability curve was derived for Ara h2. Results: The median (interquartile range [IQR]) age at OFC was 4 years (2-7 years), and 111 patients (60%) were boys. Ara h 2 was the most commonly sensitized PCT. Sixty-one patients (33%) reacted at OFC. Ara h 2 specific immunoglobulin E (sIgE) ≥ 0.35 kUA/L was associated with increased odds of reacting at OFC (odds ratio 5.91 95% confidence interval, 2.93-11.89; p < 0.001); however, 19 patients (37%) positive for Ara h 2 did not react. Ara h 2 sIgE of 0.49 kUA/L and 4.58 kUA/L were associated with 50% and 90% probability, respectively, of reacting at OFC. Among those sensitized only to Ara h 8 or 9 (n = 21), 86% had no reaction. There was no statistically significant association with polysensitization to Ara h 1, 2, and 3, and peanut OFC outcome. Conclusion: Although the Ara h 2 sIgE value was associated with clinical reactivity, a significant proportion of the patients sensitized to Ara h 2 tolerated peanut. OFC remains an important tool in the evaluation of peanut allergy.


Assuntos
Hipersensibilidade a Amendoim , Albuminas 2S de Plantas , Alérgenos , Antígenos de Plantas , Arachis , Chicago , Criança , Feminino , Humanos , Imunoglobulina E , Masculino , Hipersensibilidade a Amendoim/diagnóstico , Hipersensibilidade a Amendoim/epidemiologia , Estudos Retrospectivos
20.
J Ethn Subst Abuse ; 21(1): 284-303, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-32324108

RESUMO

The study assessed the experiences and reactions of adolescent offspring of alcohol-dependent fathers (N = 15) to their fathers' heavy drinking. Data were analyzed qualitatively, identifying themes and sub-themes. Respondent accounts elaborated these themes with reference to explanations, experiences, reactions to their fathers' drinking. Gender differences were notable: girls were more likely to report abuse, shouldering of family responsibilities, physiological and other reactions, ambivalent feelings toward father, sadness and worthlessness. Boys were more likely to react with anger and/or aggression. The findings should guide the development of gender-sensitive family-based interventions for the adolescents, with special attention to psychological, social and legal dimensions.


Assuntos
Comportamento do Adolescente/psicologia , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/psicologia , Pai , Adolescente , Feminino , Humanos , Índia , Masculino , Pesquisa Qualitativa , Fatores Sexuais , População Urbana
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