scholarly journals Transcriptional regulation of the rat platelet factor 4 gene: interaction between an enhancer/silencer domain and the GATA site.

1991 ◽  
Vol 11 (12) ◽  
pp. 6116-6127 ◽  
Author(s):  
K Ravid ◽  
T Doi ◽  
D L Beeler ◽  
D J Kuter ◽  
R D Rosenberg
Keyword(s):  
Tissue Specificity ◽  
Bone Marrow Cells ◽  
Core Promoter ◽  
Transcriptional Start Site ◽  
Human Growth ◽  
Platelet Factor 4 ◽  
Upstream Region ◽  
Growth Hormone Gene ◽  
Specific Expression ◽  
Platelet Factor

We used various segments of the 5' upstream region of the rat platelet factor 4 (PF4) gene coupled to the human growth hormone gene and heterologous promoters to identify domains which are critical for tissue-specific expression. Transient expression experiments with rat bone marrow cells and other cell lines revealed a complex interplay between a core promoter domain from -97 to the transcriptional start site and an enhancer/silencer domain from -448 to -112. The core promoter contains a GATA site at -31 to -28 whose mutation to TATA or AATA decreases tissue specificity and moderately affects expression in megakaryocytes as well as a positively acting subdomain from -97 to -83 whose removal decreases overall transcription without affecting tissue specificity. The enhancer/silencer domain possesses three positively acting subdomains from -380 to -362, -270 to -257, and -137 to -120 as well as a negatively acting subdomain at -184 to -151 which is able to reduce overall transcription but has no effect on tissue specificity. The subdomain from -380 to -362 is most critical in restricting gene expression driven either by the PF4 promoter or by a heterologous promoter to the megakaryocytic lineage. The subdomains from -270 to -257 and -137 to -120 function together with the subdomain from -380 to -362 to somewhat increase tissue specificity. Simultaneous mutation of the GATA site and deletion of either the whole enhancer/silencer domain or the subdomain from -380 to -362 or -137 to -120 reduce transcription in megakaryocytes by 10- to 30-fold. On the basis of the above-described results, we propose that the megakaryocyte-specific enhancer/silencer domain and the GATA site are responsible for high-level expression of the PF4 gene in a lineage-specific manner.

Transcriptional regulation of the rat platelet factor 4 gene: interaction between an enhancer/silencer domain and the GATA site

1991 ◽  
Vol 11 (12) ◽  
pp. 6116-6127
Author(s):  
K Ravid ◽  
T Doi ◽  
D L Beeler ◽  
D J Kuter ◽  
R D Rosenberg
Keyword(s):  
Tissue Specificity ◽  
Bone Marrow Cells ◽  
Core Promoter ◽  
Transcriptional Start Site ◽  
Human Growth ◽  
Platelet Factor 4 ◽  
Upstream Region ◽  
Growth Hormone Gene ◽  
Specific Expression ◽  
Platelet Factor

We used various segments of the 5' upstream region of the rat platelet factor 4 (PF4) gene coupled to the human growth hormone gene and heterologous promoters to identify domains which are critical for tissue-specific expression. Transient expression experiments with rat bone marrow cells and other cell lines revealed a complex interplay between a core promoter domain from -97 to the transcriptional start site and an enhancer/silencer domain from -448 to -112. The core promoter contains a GATA site at -31 to -28 whose mutation to TATA or AATA decreases tissue specificity and moderately affects expression in megakaryocytes as well as a positively acting subdomain from -97 to -83 whose removal decreases overall transcription without affecting tissue specificity. The enhancer/silencer domain possesses three positively acting subdomains from -380 to -362, -270 to -257, and -137 to -120 as well as a negatively acting subdomain at -184 to -151 which is able to reduce overall transcription but has no effect on tissue specificity. The subdomain from -380 to -362 is most critical in restricting gene expression driven either by the PF4 promoter or by a heterologous promoter to the megakaryocytic lineage. The subdomains from -270 to -257 and -137 to -120 function together with the subdomain from -380 to -362 to somewhat increase tissue specificity. Simultaneous mutation of the GATA site and deletion of either the whole enhancer/silencer domain or the subdomain from -380 to -362 or -137 to -120 reduce transcription in megakaryocytes by 10- to 30-fold. On the basis of the above-described results, we propose that the megakaryocyte-specific enhancer/silencer domain and the GATA site are responsible for high-level expression of the PF4 gene in a lineage-specific manner.

scholarly journals Structure of the rat platelet factor 4 gene: a marker for megakaryocyte differentiation.

1987 ◽  
Vol 7 (2) ◽  
pp. 898-904 ◽  
Author(s):  
T Doi ◽  
S M Greenberg ◽  
R D Rosenberg
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Genomic Library ◽  
Transcriptional Start Site ◽  
Platelet Factor 4 ◽  
Start Codon ◽  
Cdna Expression Library ◽  
Amino Acid Residues ◽  
Platelet Factor ◽  
Nuclease Mapping

A rat platelet factor 4 (PF4) cDNA has been isolated by immunoscreening a g lambda 11 rat megakaryocyte cDNA expression library. Sequence analysis of the rat PF4 cDNA revealed that this megakaryocyte protein is composed of a leader sequence of 29 amino acid residues and a mature protein sequence of 76 amino acid residues. The structure of rat PF4 derived from its cDNA shows a marked homology with the amino acid sequence of human PF4 obtained by classical protein chemistry techniques. This observation is particularly striking with regard to the carboxy-terminal region of rat and human PF4, where 28 of the last 31 C-terminal residues are identical. The rat PF4 gene was obtained from a rat genomic library by using rat PF4 cDNA as a hybridization probe. Sequence analysis showed that the gene is constructed of three exons and two short introns. The transcriptional start site is located 73 base pairs upstream of the translational start codon as judged by S1 nuclease mapping and primer extension. The 5' noncoding region of the gene also exhibited a sequence homologous to the TATA box at -31, as well as a series of direct and inverted repeat sequences and a cluster of 26 T residues at -155 to -218. This latter domain may be involved in regulating PF4 gene expression during megakaryocytopoiesis.

Localization of distal regulatory domains in the megakaryocyte-specific platelet basic protein/platelet factor 4 gene locus

Blood ◽  
2001 ◽  
Vol 98 (3) ◽  
pp. 610-617 ◽  
Author(s):  
Chunyan Zhang ◽  
Michael A. Thornton ◽  
M. Anna Kowalska ◽  
Bruce S. Sachis ◽  
Michael Feldman ◽  
...  
Keyword(s):  
Gene Locus ◽  
Basic Protein ◽  
Regulatory Region ◽  
Platelet Factor 4 ◽  
Specific Gene ◽  
Sufficient Information ◽  
Specific Expression ◽  
Platelet Factor ◽  
High Level

Abstract The genes for the related human (h) chemokines, PBP (platelet basic protein) and PF4 (platelet factor 4), are within 5.3 kilobases (kb) of each other and form a megakaryocyte-specific gene locus. The hypothesis was considered that the PBP and PF4 genes share a common distal regulatory region(s) that leads to their high-level megakaryocyte-specific expression in vivo. This study examined PBP and PF4 expression in transgenic mice using 4 distinct humanPBP/PF4 gene locus constructs. These studies showed that within the region studied there was sufficient information to regulate tissue-specific expression of both hPBP and hPF4. Indeed this region contained sufficient DNA information to lead to expression levels of PBP and PF4 comparable to the homologous mouse genes in a position-independent, copy number–dependent fashion. These studies also indicated that the DNA domains that led to this expression were distinct for the 2 genes; hPBP expression is regulated by a region that is 1.5 to 4.4 kb upstream of that gene. Expression of hPF4 is regulated by a region that is either intergenic between the 2 genes or immediately downstream of the hPF4 gene. Comparison of the available human and mouse sequences shows conserved flanking region domains containing potential megakaryocyte-related transcriptional factor DNA-binding sites. Further analysis of these regulatory regions may identify enhancer domains involved in megakaryopoiesis that may be useful in the selective expression of other genes in megakaryocytes and platelets as a strategy for regulating hemostasis, thrombosis, and inflammation.

scholarly journals Determinants of rat albumin promoter tissue specificity analyzed by an improved transient expression system.

1987 ◽  
Vol 7 (7) ◽  
pp. 2425-2434 ◽  
Author(s):  
J M Heard ◽  
P Herbomel ◽  
M O Ott ◽  
A Mottura-Rollier ◽  
M Weiss ◽  
...  
Keyword(s):  
Transient Expression ◽  
Tissue Specificity ◽  
Transcriptional Start Site ◽  
Expression System ◽  
Hepatoma Cells ◽  
Sequence Motif ◽  
Specific Expression ◽  
Tissue Specific ◽  
Albumin Gene ◽  
Ccaat Box

The 150-base-pairs region located upstream of the transcriptional start site of the rat albumin gene contains all of the critical sequences necessary for this gene's tissue-specific expression in rat hepatoma cells. In transient expression assays using an improved CAT system or direct mRNA analysis we were able to detect a faithful transcription from the albumin promoter in albumin-negative dedifferentiated H5 hepatoma cells which was 250-fold weaker than in differentiated H4II hepatoma cells producing albumin. This strong tissue specificity could be completely overcome through the cis action of a non-tissue-specific enhancer. Two upstream regions from nucleotides -151 to -119 and from -118 to -94, were required for efficient transcription in H4II cells. Each region contained a sequence motif highly conserved among different species. The effect of the -151/-119 region was strictly tissue specific, while the -118/-94 region was also involved in the low level of transcription observed in H5 cells. Finally, sequences between the CCAAT box and the TATA box also contributed to the overall tissue specificity of rat albumin gene transcription.

A rat gastrin-human gastrin chimeric transgene directs antral G cell-specific expression in transgenic mice

1995 ◽  
Vol 268 (6) ◽  
pp. G1025-G1036 ◽  
Author(s):  
T. C. Wang ◽  
M. W. Babyatsky ◽  
P. S. Oates ◽  
Z. Zhang ◽  
L. Tillotson ◽  
...  
Keyword(s):  
Germ Line ◽  
Peptide Yy ◽  
Human Growth ◽  
Growth Hormone Gene ◽  
Specific Expression ◽  
Cis Acting ◽  
G Cells ◽  
Human Gastrin ◽  
Immunohistochemical Studies

Gastrin gene expression in the gastrointestinal tract is under both developmental and spatial regulation. In the mature animal, gastrin, an important regulator of parietal acid secretion, is expressed primarily in G cells of the antrum. To determine whether specific promoter elements can direct expression to the gastric antrum in vivo, 450 nucleotides of the proximal rat gastrin promoter were cloned and used to construct a rat gastrin-human gastrin reporter chimeric transgene, which was injected into the mouse germ line. Northern blot analysis, in situ hybridization, and double-label immunocytochemistry studies demonstrated expression of the transgene specifically in antral G cells. Low levels of transgene expression were observed in the ileum and colon, where immunohistochemical studies demonstrated colocalization in enteroendocrine cells expressing peptide YY. The same 450-nucleotide rat gastrin promoter, when joined to the human growth hormone gene, did not result in antral expression. Similarly, a human gastrin-human gastrin reporter transgene also did not achieve antral expression, although it did express in the liver. These results suggest that cis-acting elements present in both the basal 450-nucleotide rat gastrin promoter and the intragenic sequences of the human gastrin gene are necessary to direct expression of a transgene specifically to antral G cells.

scholarly journals Platelet Factor 4 and Other CXC Chemokines Support the Survival of Normal Hematopoietic Cells and Reduce the Chemosensitivity of Cells to Cytotoxic Agents

Blood ◽  
1997 ◽  
Vol 89 (7) ◽  
pp. 2328-2335 ◽  
Author(s):  
Zhong Chao Han ◽  
Min Lu ◽  
Junmin Li ◽  
Mai Defard ◽  
Bernadette Boval ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Growth Factor ◽  
Cell Lines ◽  
Cancer Cell ◽  
Bone Marrow Cells ◽  
Hematopoietic Cells ◽  
Platelet Factor 4 ◽  
Cytotoxic Agents ◽  
Platelet Factor ◽  
Cd34 Cells

Abstract The effects of platelet factor 4 (PF4) on the viability and chemosensitivity of normal hematopoietic cells and cancer cell lines were studied to determine the mechanisms whereby PF4 functions as either an inhibitor or a protector and to evaluate its clinical significance. Two other chemokines, interleukin-8 (IL-8) and neutrophil-activating peptide-2 (NAP-2), were also studied in comparison to PF4. Using a tetrazolium salt assay for cell viability, we observed that PF4 at 1 to 50 μg/mL supported the viability of normal human bone marrow cells. Approximately 45% of cells cultured for 48 hours survived, whereas 80% or more survived in the presence of PF4 5 μg/mL. PF4 also supported the viability of CD34+ cord blood (CB) cells and protected them from apoptosis induced by transforming growth factor β1 (TGFβ1) and cytotoxic drugs. Pretreatment of CD34+ cells by PF4, but not by TGFβ1, caused an increase in the number of megakaryocyte colonies after these cells were replated in secondary cultures. Flow cytometry analysis showed that when CD34+ cells were preincubated with PF4 or TGFβ1 for 12 days in hematopoietic growth factor–rich medium, an increased number of remaining CD34+ cells was observed only for PF4-treated cells. Furthermore, PF4 significantly reduced the chemosensitivity of bone marrow cells, as shown by its ability to increase the 50% inhibition concentration (IC50) of several cytotoxic agents. Like PF4, IL-8 and NAP-2 at 0.1, 0.6, and 1 μg/mL supported the survival of myeloid progenitors, including colony-forming units granulocyte, erythroblast, monocyte, megakaryocyte (CFU-GEMM), CFU-megakaryocyte (CFU-MK), CFU–granulocyte/macrophage (CFU-GM), and burst-forming units–erythroblast (BFU-E), and reduced their sensitivity to the toxicity of etoposide (ETP). Protamine sulfate at 1 to 100 μg/mL showed no such activity of PF4. Interestingly, the three chemokines failed to affect significantly the viability and chemosensitivity of three leukemic and two other tumor cell lines. Based on these results, we conclude for the first time that PF4 and IL-8 and NAP-2 support the survival of normal hematopoietic precursors and protect them from the toxicity of chemotherapeutic agents. Because such activities are unique to normal hematopoietic cells but not to the cancer cell lines evaluated, a potential clinical application of these molecules in the treatment of cancer is suggested.

Live Attenuated Salmonella Carrying Platelet Factor 4 cDNAs as Radioprotection and Anti-Tumor Angiogenesis Agents.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3178-3178
Author(s):  
Zhong Chao Han ◽  
Bin Liu ◽  
Lihua Zhao
Keyword(s):  
Gene Therapy ◽  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Tumor Regression ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Delivery Vector ◽  
Total Body ◽  
Marrow Cells

Abstract In cancer therapy, specific radioprotection of normal tissue and antiangiogenesis are the ways to increase the therapeutic gain. Here we describe a novel gene therapy, which uses attenuated salmonella SL3261 as oral vectors carrying with cDNA of platelet factor 4 (PF4) or that of a truncated PF4. After oral administrations of attenuated salmonella carrying with cDNA of PF4 or truncated PF4, the survival rate of mice which received sublethal total body irradiation was improved by 50%, In comparison with the control mice, the bone marrow cells obtained from the mice of experimental group increased (13.2±8.3, 15.7±1.5 vs 4.1 ± 2.0 P<0.05) at day 7 after TBI, and the number of HPP-CFC of bone marrow cells also increased significantly (15.7±9, 11.7±5 vs 4.3±4.1 P<0.05) at day 7, suggesting a stimulating effect of PF4 on hematopoietic recovery. This gene therapy also caused significant tumor regression. The microvessel density (MVD) of tumors was significantly decreased in the group of treated mice compared to controls (4.25±0.96, 4.08±0.56 vs 11±0.83 P<0.05). Analysis TUNEL kit revealed an increase in the number of apoptosis cells in tumors of mice treated by SL3261 carrying with cDNA of PF4 or a truncated PF4. GFP expression and gene integration were detected in the liver, kidney, spleens, intestine, peripheral blood, bone marrow and tumors samples of the SL3261 treated mice, and the expression of GFP was higher in tumors than that in other tissues. These data demonstrate for the first time a dual biological function of PF4 against tumor growth and radiation injury. These results also demonstrate that attenuated salmonella can be used in vivo as a DNA delivery vector

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