Use of phenylhydrazine in the detection of responsive changes in haemoglobin isomorph abundances

1988 ◽  
Vol 66 (3) ◽  
pp. 758-762 ◽  
Author(s):  
Annette P. Byrne ◽  
A. H. Houston
Keyword(s):  
Gene Expression ◽  
Rainbow Trout ◽  
Environmental Change ◽  
Globin Gene ◽  
Salmo Gairdneri ◽  
Respiratory Response ◽  
Phenylhydrazine Hydrochloride ◽  
Total Hemoglobin ◽  
Response To Environmental Change ◽  
Globin Gene Expression

The possible masking of responsive adjustments in hemoglobin isomorph abundances was examined in rainbow trout, Salmo gairdneri. Comparison of untreated animals with specimens recovering from anemia induced by phenylhydrazine hydrochloride at 14 °C under normoxic circumstances revealed significant differences in the relative abundances of 8 of 12 isomorphs representing over half of the total hemoglobin complement. Comparisons with trout similarly treated after normoxic acclimation to 20 °C led to very similar findings. Observed differences do not appear to be attributable to direct phenylhydrazine effects on globin gene expression or to acute anemic hypoxia. It is suggested that prior induction of anemia may provide a means for improving detection of changes in hemoglobin isomorph complement during respiratory response to environmental change.

scholarly journals Epigenetic Insights and Potential Modifiers as Therapeutic Targets in β–Thalassemia

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 755
Author(s):  
Nur Atikah Zakaria ◽  
Md Asiful Islam ◽  
Wan Zaidah Abdullah ◽  
Rosnah Bahar ◽  
Abdul Aziz Mohamed Yusoff ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clinical Presentation ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Dna Hypomethylation ◽  
Considerable Research ◽  
Non Coding Rna ◽  
Hbf Level ◽  
Long Non Coding Rna ◽  
Globin Gene Expression

Thalassemia, an inherited quantitative globin disorder, consists of two types, α– and β–thalassemia. β–thalassemia is a heterogeneous disease that can be asymptomatic, mild, or even severe. Considerable research has focused on investigating its underlying etiology. These studies found that DNA hypomethylation in the β–globin gene cluster is significantly related to fetal hemoglobin (HbF) elevation. Histone modification reactivates γ-globin gene expression in adults and increases β–globin expression. Down-regulation of γ–globin suppressor genes, i.e., BCL11A, KLF1, HBG-XMN1, HBS1L-MYB, and SOX6, elevates the HbF level. β–thalassemia severity is predictable through FLT1, ARG2, NOS2A, and MAP3K5 gene expression. NOS2A and MAP3K5 may predict the β–thalassemia patient’s response to hydroxyurea, a HbF-inducing drug. The transcription factors NRF2 and BACH1 work with antioxidant enzymes, i.e., PRDX1, PRDX2, TRX1, and SOD1, to protect erythrocytes from oxidative damage, thus increasing their lifespan. A single β–thalassemia-causing mutation can result in different phenotypes, and these are predictable by IGSF4 and LARP2 methylation as well as long non-coding RNA expression levels. Finally, the coinheritance of β–thalassemia with α–thalassemia ameliorates the β–thalassemia clinical presentation. In conclusion, the management of β–thalassemia is currently limited to genetic and epigenetic approaches, and numerous factors should be further explored in the future.

Regulation of human globin gene expression in mouse erythroleukemia � human fibroblast hybrid cells

1982 ◽  
Vol 8 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Devi Vembu ◽  
Neal S. Young ◽  
Marcia Willing ◽  
Eve Church ◽  
Linda Sanders-Haigh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Fibroblast ◽  
Globin Gene ◽  
Hybrid Cells ◽  
Globin Gene Expression ◽  
Mouse Erythroleukemia

scholarly journals Mi2β-mediated silencing of the fetal γ-globin gene in adult erythroid cells

Blood ◽  
2013 ◽  
Vol 121 (17) ◽  
pp. 3493-3501 ◽  
Author(s):  
Maria Amaya ◽  
Megha Desai ◽  
Merlin Nithya Gnanapragasam ◽  
Shou Zhen Wang ◽  
Sheng Zu Zhu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Major Part ◽  
Globin Gene ◽  
Globin Genes ◽  
Erythroid Cells ◽  
Key Points ◽  
Globin Gene Expression ◽  
Partial Depletion

Key Points Mi2β exerts a major part of its silencing effect on embryonic and fetal globin genes by positively regulating the BCL11A and KLF1 genes. Partial depletion of Mi2β induces increased γ-globin gene expression in primary human erythroid cells without impairing differentiation.

scholarly journals Long-Distance Control of Origin Choice and Replication Timing in the Human β-Globin Locus Are Independent of the Locus Control Region

2000 ◽  
Vol 20 (15) ◽  
pp. 5581-5591 ◽  
Author(s):  
Daniel M. Cimbora ◽  
Dirk Schübeler ◽  
Andreas Reik ◽  
Joan Hamilton ◽  
Claire Francastel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Control Region ◽  
Globin Gene ◽  
Replication Timing ◽  
S Phase ◽  
Chromatin Conformation ◽  
Erythroid Cells ◽  
Long Distance ◽  
Targeted Deletion ◽  
Globin Gene Expression

ABSTRACT DNA replication in the human β-globin locus is subject to long-distance regulation. In murine and human erythroid cells, the human locus replicates in early S phase from a bidirectional origin located near the β-globin gene. This Hispanic thalassemia deletion removes regulatory sequences located over 52 kb from the origin, resulting in replication of the locus from a different origin, a shift in replication timing to late S phase, adoption of a closed chromatin conformation, and silencing of globin gene expression in murine erythroid cells. The sequences deleted include nuclease-hypersensitive sites 2 to 5 (5′HS2-5) of the locus control region (LCR) plus an additional 27-kb upstream region. We tested a targeted deletion of 5′HS2-5 in the normal chromosomal context of the human β-globin locus to determine the role of these elements in replication origin choice and replication timing. We demonstrate that the 5′HS2-5-deleted locus initiates replication at the appropriate origin and with normal timing in murine erythroid cells, and therefore we conclude that 5′HS2-5 in the classically defined LCR do not control replication in the human β-globin locus. Recent studies also show that targeted deletion of 5′HS2-5 results in a locus that lacks globin gene expression yet retains an open chromatin conformation. Thus, the replication timing of the locus is closely correlated with nuclease sensitivity but not globin gene expression.

scholarly journals 5'-flanking sequences mediate butyrate stimulation of embryonic globin gene expression in adult erythroid cells.

1991 ◽  
Vol 11 (9) ◽  
pp. 4690-4697 ◽  
Author(s):  
J G Glauber ◽  
N J Wandersee ◽  
J A Little ◽  
G D Ginder
Keyword(s):  
Gene Expression ◽  
Cell Differentiation ◽  
Globin Gene ◽  
Beta Globin ◽  
Erythroid Cells ◽  
Adult Chicken ◽  
Beta Globin Gene ◽  
Flanking Sequences ◽  
Murine Erythroleukemia ◽  
Globin Gene Expression

A stable transfection assay was used to test the mechanism by which embryonic globin gene transcription is stimulated in adult erythroid cells exposed to butyric acid and its analogs. To test the appropriate expression and inducibility of chicken globin genes in murine erythroleukemia (MEL) cells, an adult chicken beta-globin gene construct was stably transfected. The chicken beta-globin gene was found to be coregulated with the endogenous adult mouse alpha-globin gene following induction of erythroid differentiation of the transfected MEL cells by incubation with either 2% dimethyl sulfoxide (DMSO) or 1 mM sodium butyrate (NaB). In contrast, a stably transfected embryonic chicken beta-type globin gene, rho, was downregulated during DMSO-induced MEL cell differentiation. However, incubation with NaB, which induces MEL cell differentiation, or alpha-amino butyrate, which does not induce differentiation of MEL cells, resulted in markedly increased levels of transcription from the stably transfected rho gene. Analysis of histone modification showed that induction of rho gene expression was not correlated with increased bulk histone acetylation. A region of 5'-flanking sequence extending from -569 to -725 bp upstream of the rho gene cap site was found to be required for both downregulation of rho gene expression during DMSO-induced differentiation and upregulation by treatment with NaB or alpha-amino butyrate. These data are support for a novel mechanism by which butyrate compounds can alter cellular gene expression through specific DNA sequences. The results reported here are also evidence that 5'-flanking sequences are involved in the suppression of embryonic globin gene expression in terminally differentiated adult erythroid cells.

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