Down-regulation of miRNA-451a and miRNA-486-5p involved in benzene-induced inhibition on erythroid cell differentiation in vitro and in vivo

We use murine erythroid Friend cells and human promyelocytic HL60 cells to investigate the influence of a transmembrane signal in triggering myeloid or erythroid cell differentiation. Combined treatments were given with dimethylsulfoxide, actinomycin D and amphotericin B, a substance which resembles a deviant membrane lipid and which seems to influence exclusively membrane activity. Our results suggest that a membrane modification alone is sufficient for in vitro HL60 cell differentiation, whereas both a transmembrane and a nuclear signal are necessary for Friend cell differentiation.

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Gene Expression Studies Reveal a Potential Mechanism of Glivec Resistance in Patients with Ph+ ALL Treated.

Blood ◽

10.1182/blood.v106.11.4374.4374 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4374-4374

Author(s):

To Ha Loi ◽

David D.F. Ma

Keyword(s):

Gene Expression ◽

Cell Differentiation ◽

B Cell ◽

Cell Lines ◽

Unexpected Finding ◽

B Cell Differentiation ◽

Down Regulation ◽

Blast Cells

Abstract In Ph+ ALL, patients respond to Glivec but nearly always relapse due to acquired resistance. The biological processes associated with Glivec resistance in Ph+ ALL are yet to be fully elucidated. The aim of this study is to use microarray and Q-PCR technology to dissect changes in signaling pathways of blast cells in Ph+ ALL patients treated with Glivec. Peripheral blood (PB) samples were taken before treatment and on consecutive days after administration of Glivec from two Ph+, c-ALLA+ and CD19+ ALL patients. Blast cells were isolated and their gene expression assayed using 19K cDNA microarrays. Over 400 differentially expressed genes were identified with at least a 1.5-fold up- or down-regulation in treated cells compared to cells collected pre-treatment. Based on these gene expression results, three main gene ontology groups were further evaluated: Apoptosis, Proliferation and B cell differentiation. The up-regulation of Bim and Bcl-6, and down regulation of Cyclin D2, confirms the induction of apoptosis via the FOXO3a pathway in cells treated with Glivec in vivo. Interestingly, both the proliferation genes, Tcl1-A and PKCe, and B cell differentiation associated genes, including CD79a, ETS1 and a cohort of IGH and Igl and k genes, were up-regulated during therapy. These gene expression changes observed in vivo were confirmed by Q-PCR in the Ph+ cell lines K562 (derived from CML blast crisis) and SUP-B15 (derived from ALL) treated with Glivec. The unexpected finding of increased expression of pro-proliferative genes and B cell differentiation genes by microarray revealed potential links with early B cell development and B cell receptor (BCR) signaling. Evidence for apoptosis and proliferation of Ph+ cell lines treated with Glivec were then examined by FACs. After 5 days of treatment with Glivec, 90% of K562 and 50% SUP-B15 cells underwent apoptosis. Furthermore, cell cycle analysis revealed the existence of a population of cells in G2 phase even after 6 days of Glivec treatment in SUP-B15 but not K562 cells, thus providing evidence of a population of cells undergoing proliferation during Glivec treatment in vitro. In summary, our in vivo observations supported by in vitro experiments suggest that Glivec induces the majority of Ph+ ALL blasts to undergo apoptosis. However, as treatment is prolonged, a population of ALL cells escapes death and undergoes proliferation and differentiation. We hypothesise that Glivec induced differentiation and proliferation of Ph+ cells may result in the clonal enrichment of cells resistant to Glivec.

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CREB-Binding Protein Acetylates Hematopoietic Transcription Factor GATA-1 at Functionally Important Sites

Molecular and Cellular Biology ◽

10.1128/mcb.19.5.3496 ◽

1999 ◽

Vol 19 (5) ◽

pp. 3496-3505 ◽

Cited By ~ 179

Author(s):

Hsiao-Ling Hung ◽

Jason Lau ◽

Alexander Y. Kim ◽

Mitchell J. Weiss ◽

Gerd A. Blobel

Keyword(s):

Transcription Factor ◽

Mammalian Cells ◽

Transcriptional Activity ◽

Binding Protein ◽

Erythroid Differentiation ◽

Erythroid Cell ◽

Creb Binding Protein ◽

Erythroid Cell Differentiation

ABSTRACT The transcription factor GATA-1 is a key regulator of erythroid-cell differentiation and survival. We have previously shown that the transcriptional cofactor CREB-binding protein (CBP) binds to the zinc finger domain of GATA-1, markedly stimulates the transcriptional activity of GATA-1, and is required for erythroid differentiation. Here we report that CBP, but not p/CAF, acetylates GATA-1 at two highly conserved lysine-rich motifs present at the C-terminal tails of both zinc fingers. Using [3H]acetate labelling experiments and anti-acetyl lysine immunoprecipitations, we show that GATA-1 is acetylated in vivo at the same sites acetylated by CBP in vitro. In addition, we show that CBP stimulates GATA-1 acetylation in vivo in an E1A-sensitive manner, thus establishing a correlation between acetylation and transcriptional activity of GATA-1. Acetylation in vitro did not alter the ability of GATA-1 to bind DNA, and mutations in either motif did not affect DNA binding of GATA-1 expressed in mammalian cells. Since certain functions of GATA-1 are revealed only in an erythroid environment, GATA-1 constructs were examined for their ability to trigger terminal differentiation when introduced into a GATA-1-deficient erythroid cell line. We found that mutations in either acetylation motif partially impaired the ability of GATA-1 to induce differentiation while mutations in both motifs abrogated it completely. Taken together, these data indicate that CBP is an important cofactor for GATA-1 and suggest a novel mechanism in which acetylation by CBP regulates GATA-1 activity in erythroid cells.

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Inhibition of CBP-Mediated Protein Acetylation by the Ets Family Oncoprotein PU.1

Molecular and Cellular Biology ◽

10.1128/mcb.22.11.3729-3743.2002 ◽

2002 ◽

Vol 22 (11) ◽

pp. 3729-3743 ◽

Cited By ~ 47

Author(s):

Wei Hong ◽

Alexander Y. Kim ◽

Sokun Ky ◽

Carrie Rakowski ◽

Sang-Beom Seo ◽

...

Keyword(s):

Cell Differentiation ◽

Cellular Proliferation ◽

Erythroid Cell ◽

Specific Gene ◽

Protein Acetylation ◽

Aberrant Expression ◽

Nuclear Factors ◽

Ets Family ◽

Erythroid Cell Differentiation

ABSTRACT Aberrant expression of PU.1 inhibits erythroid cell differentiation and contributes to the formation of murine erythroleukemias (MEL). The molecular mechanism by which this occurs is poorly understood. Here we show that PU.1 specifically and efficiently inhibits CBP-mediated acetylation of several nuclear proteins, including the hematopoietic transcription factors GATA-1, NF-E2, and erythroid Krüppel-like factor. In addition, PU.1 blocks acetylation of histones and interferes with acetylation-dependent transcriptional events. CBP acetyltransferase activity increases during MEL cell differentiation as PU.1 levels decline and is inhibited by sustained PU.1 expression. Finally, PU.1 inhibits the differentiation-associated increase in histone acetylation at an erythroid-specific gene locus in vivo. Together, these findings suggest that aberrant expression of PU.1 and possibly other members of the Ets family of oncoproteins subverts normal cellular differentiation in part by inhibiting the acetylation of critical nuclear factors involved in balancing cellular proliferation and maturation.

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Decreased differentiation of erythroid cells exacerbates ineffective erythropoiesis in β-thalassemia

Blood ◽

10.1182/blood-2007-12-126938 ◽

2008 ◽

Vol 112 (3) ◽

pp. 875-885 ◽

Cited By ~ 95

Author(s):

Ilaria V. Libani ◽

Ella C. Guy ◽

Luca Melchiori ◽

Raffaella Schiro ◽

Pedro Ramos ◽

...

Keyword(s):

Cell Differentiation ◽

S Phase ◽

Erythroid Cell ◽

Erythroid Cells ◽

Ineffective Erythropoiesis ◽

Ki 67 ◽

Jak2 Inhibitor ◽

Normal Percentage ◽

Erythroid Cell Differentiation

Abstract In β-thalassemia, the mechanism driving ineffective erythropoiesis (IE) is insufficiently understood. We analyzed mice affected by β-thalassemia and observed, unexpectedly, a relatively small increase in apoptosis of their erythroid cells compared with healthy mice. Therefore, we sought to determine whether IE could also be characterized by limited erythroid cell differentiation. In thalassemic mice, we observed that a greater than normal percentage of erythroid cells was in S-phase, exhibiting an erythroblast-like morphology. Thalassemic cells were associated with expression of cell cycle–promoting genes such as EpoR, Jak2, Cyclin-A, Cdk2, and Ki-67 and the antiapoptotic protein Bcl-XL. The cells also differentiated less than normal erythroid ones in vitro. To investigate whether Jak2 could be responsible for the limited cell differentiation, we administered a Jak2 inhibitor, TG101209, to healthy and thalassemic mice. Exposure to TG101209 dramatically decreased the spleen size but also affected anemia. Although our data do not exclude a role for apoptosis in IE, we propose that expansion of the erythroid pool followed by limited cell differentiation exacerbates IE in thalassemia. In addition, these results suggest that use of Jak2 inhibitors has the potential to profoundly change the management of this disorder.

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In-vitro- und In-vivo-Wirkung von Schilddrüsenhormon auf das Wachstum von Neuroblastomzellen

Nuklearmedizin ◽

10.1055/s-0038-1629520 ◽

1990 ◽

Vol 29 (03) ◽

pp. 120-124

Author(s):

R. P. Baum ◽

E. Rohrbach ◽

G. Hör ◽

B. Kornhuber ◽

E. Busse

Keyword(s):

Cell Differentiation ◽

Neuroblastoma Cells ◽

Control Group ◽

Initial Value ◽

Initial Rise ◽

Biphasic Effect ◽

Contrast Microscopy ◽

Morphological Sign

The effect of triiodothyronine (T3) on the differentiation of cultured neuroblastoma (NB) cells was studied after 9 days of treatment with a dose of 10-4 M/106 cells per day. Using phase contrast microscopy, 30-50% of NB cells showed formation of neurites as a morphological sign of cellular differentiation. The initial rise of the mitosis rate was followed by a plateau. Changes in cyclic nucleotide content, in the triphosphates and in the activity of the enzyme ornithine decarboxylase (ODC) were assessed in 2 human and 2 murine cell lines to serve as biochemical parameters of the cell differentiation induced by T3. Whereas the cAMP level increased significantly (3 to 7 fold compared with its initial value), the cGMP value dropped to 30 to 50% of that of the control group. ATP and GTP increased about 200%, the ODC showed a decrease of about 50%. The present studies show a biphasic effect of T3 on neuroblastoma cells: the initial rise of mitotic activity is followed by increased cell differentiation starting from day 4 of the treatment.

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Changes in globin messenger RNA content during erythroid cell differentiation.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)41157-5 ◽

1975 ◽

Vol 250 (15) ◽

pp. 6054-6058

Author(s):

F Ramirez ◽

R Gambino ◽

G M Maniatis ◽

R A Rifkind ◽

P A Marks ◽

...

Keyword(s):

Cell Differentiation ◽

Messenger Rna ◽

Erythroid Cell ◽

Rna Content ◽

Erythroid Cell Differentiation

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LINGO-1 shRNA protects the brain against ischemia/reperfusion injury by inhibiting the activation of NF-κB and JAK2/STAT3

Human Cell ◽

10.1007/s13577-021-00527-x ◽

2021 ◽

Author(s):

Jiaying Zhu ◽

Zhu Zhu ◽

Yipin Ren ◽

Yukang Dong ◽

Yaqi Li ◽

...

Keyword(s):

Cerebral Ischemia ◽

Nuclear Translocation ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Glucose Deprivation ◽

Artery Occlusion ◽

Mice Model ◽

Down Regulation

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.

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Study of yolk-sac endoderm organogenesis in the chick using a specific enzyme (cysteine lyase) as a marker of cell differentiation

Development ◽

10.1242/dev.29.1.159 ◽

1973 ◽

Vol 29 (1) ◽

pp. 159-174

Author(s):

Nelly Bennett

Keyword(s):

Cell Differentiation ◽

Blood Cells ◽

Primitive Streak ◽

Yolk Sac ◽

Specific Enzyme ◽

Cell Proliferation And Differentiation ◽

Lyase Activity ◽

Morphological Specialization

The detection of a specific enzyme (cysteine lyase) of the yolk-sac endoderm by a very sensitive method is employed to characterize cell differentiation during the early stages of endoderm organogenesis in the chick. The first cells to contain active cysteine lyase are found in the germ wall at the primitive streak stage. In vivo observations establish a relation between the morphological specialization and organization of endodermal cells, their loss of mitotic activity and the increase in cysteine lyase activity. They suggest an influence of the mesoderm on endoderm differentiation. In vitro experiments confirm the existence in the yolk-sac endoderm of an incompatibility between cell proliferation and differentiation, as well as the action of the mesoderm on both the structural organization of the endoblast and the appearance of cysteine lyase; this last action seems to be due mainly to blood cells; chicken and rabbit blood cells are equally active. The problems of the origin of the endoderm and of the interactions occurring during the organogenesis of the yolk-sac endoderm are discussed.

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