Identification of mRNA for PDGF B‐chain in human megakaryocytes isolated using a novel immunomagnetic separation method

Gladwin, A. M.; Carrier, Martin; Beesley, Julian E.; Lelchuk, Rosalia; Hancock, Viktoria; Martin, John F.

doi:10.1111/j.1365-2141.1990.tb06364.x

Cited by 50 publications

(22 citation statements)

References 22 publications

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“…As I have already mentioned, larger than normal megakaryocytes have been observed in bronchial carcinoma [83]. The platelet content of PDGF is determined by the megakaryocyte mRNA for PDGF [63]. In carcinoma of the lung, clubbing and HOA might be influenced by altered PDGF synthetic ability of megakaryocytes, as well as by the right-to-left shunt created by the tumour circulation.…”

Section: Hypertrophic Osteoarthropathy (Hoa)mentioning

confidence: 91%

The aetiology of clubbing and hypertrophic osteoarthropathy

Dickinson

1993

Eur J Clin Investigation

133

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Abstract. The evidence is reviewed for the hypothesis that clubbing and hypertrophic osteoarthropathy are due to the peripheral impaction of megakaryocytes and platelet clumps in the fingers and toes, to which this particulate matter has passed in an axial stream. The normal pulmonary vascular bed retains these large particles, which fragment before entering the systemic circulation. A right-to-left shunt allows them to bypass the pulmonary vascular bed. A preliminary histological report of platelet clumps seen at necropsy in nail bed capillaries of clubbed fingers supports the hypothesis. Platelets contain and release platelet-derived growth factor, whose known effects could explain all the pathological changes in clubbing. In addition to explaining why clubbing should occur in cyanotic congenital heart disease, clubbing in sub-acute bacterial endocarditis and distal to infected arterial grafts and aneurysms can be understood in terms of platelet clumps breaking off valves or arterial walls, and passing distally. Clubbing in liver disease is associated with multiple small pulmonary arteriovenous anastomoses which allow large particles through. Hypertrophic osteoarthropathy probably shares the same mechanism, and is mainly attributable to PDGF release; but there may also be altered platelet function and an additional growth factor derived from the lungs.

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Section: Hypertrophic Osteoarthropathy (Hoa)mentioning

confidence: 91%

The aetiology of clubbing and hypertrophic osteoarthropathy

Dickinson

1993

Eur J Clin Investigation

133

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“…Intramedullar TGF-b is located mainly in megakaryocytes (Fava et al, 1990;Glandwin, 1990). Since the levels of TGF-b1 in the marrow fluid were markedly increased, it is likely that PEG-rHuMGDF directly or indirectly induces the release of TGF-b1 from marrow megakaryocytes.…”

Section: Discussionmentioning

confidence: 99%

“…PDGF is a major mitogen for mesenchymal cells such as fibroblasts and smooth muscle cells (Heldin, 1992;Ross et al, 1986). Both cytokines are located mainly in the a-granules of megakaryocyes and platelets (Fava et al, 1990;Glandwin et al, 1990).…”

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confidence: 99%

The role of transforming growth factor‐β in PEG‐rHuMGDF‐induced reversible myelofibrosis in rats

et al. 1997

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Summary. Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) injected at a suprapharmacologic dose (100 mg/kg) daily for 5 d in normal rats caused marked increases in marrow megakaryocytes and platelet counts at 6-8 d followed by gradual decreases to control levels at 10-20 d. Interestingly, in addition to the expected thrombopoiesis, PEG-rHuMGDF was associated with myelofibrosis with a predominance of reticulin fibres at day 10 followed by complete normalization by day 20. At 6-8 d, the levels of transforming growth factor-b1 (TGF-b1) in the extracellular fluid of the marrow, the platelet poor plasma, and the platelet extract were increased 23-, 7-and 2-fold, respectively. The elevated levels of TGF-b1 were gradually reduced to baseline levels at 13-20 d in accordance with the normalization of myelofibrosis and thrombopoiesis. An ultrastructural analysis showed that large fragments of megakaryocytes were deposited in the marrow parenchyma of PEG-rHuMGDF-treated rats at day 6. PEG-rHuMGDF administration at pharmacologic doses (1 and 10 mg/kg) did not induce the deposition of reticulin fibres in the marrow. These findings suggest that TGF-b1 leaked from megakaryocytes is involved in the development of the PEG-rHuMGDF-induced myelofibrosis and that this is a reversible process related to the regulation of the excess production of platelets.

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“…The human c-sis gene is specifically expressed in very diverse cell-types, such as placental cytotrophoblasts (Goustin et al, 1985), bone marrow megakaryocytes (Gladwin et al, 1990), vascular endothelial cells (DiCorleto and BowenPope, 1983) and smooth muscle cells (Seifert et al, 1984). Previous studies indicated that the amount of 3.5-kb c-sis mRNA is mainly regulated at the transcription level (Colamonici et al, 1986;Daniel and Fen, 1988;Kavanaugh et al, 1988;Harsh et al, 1989;Press et al, 1988;Dirks et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

“…Blood platelets, from which PDGF was originally purified, lack transcriptional machinery. Transcription of the c-sis gene takes place in their precursor cells, the bone marrow megakaryocytes (Gladwin et al, 1990). Human leukemia cell line K562 can be induced to differentiate toward megakaryocytes by treatment with phorbol-esters, which is accompanied by highly increased transcription of the c-sis gene and expression of PDGF (Colamonici et al, 1986;Alitalo et al, 1987).…”

mentioning

confidence: 99%

DNase‐I‐hypersensitive sites located far upstream of the human c‐sis/PDGF‐B gene comap with transcriptional enhancers and a silencer and are preceded by (part of) a new transcription unit

Dirks

Jansen

Onnekink

et al. 1993

European Journal of Biochemistry

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The human c-sis gene encodes the B chain of platelet-derived growth factor (PDGF), a potent mitogen for cultured cells of mesenchymal origin. PDGF is stored in the a-granules of blood platelets, which are derived from bone marrow megakaryocytes and lack transcriptional machinery. Human myeloid leukemia cell line K562 can be used as a model for megakaryocytes. Phorbol-estermediated megakaryocytic differentiation of K562 cells is accompanied by more than 200-fold increase in the c-sis mRNA level. We have now localized transcriptional enhancers at -8.6 kb and -9.9 kb relative to the human c-.six gene transcription start site. The enhancer at -8.6 kb increases activity of the c-sis promoter by 40-60-fold specifically in K562 cells and comaps with a DNase-I-hypersensitivity (DH) site. The enhancer at -9.9 kb increases c-sis promoter activity by 5 -10-fold in K562 cells and DH at that site accompanies phorbol-ester-induced megakaryocytic differentiation. In phorbol-ester-treated K562 cells the two enhancers may be negatively influenced by a silencer that comaps with DH at -10.7/-11 .O kb. Reporter gene analysis predicted that combined activity of the upstream enhancers and the c-sis promoter may result in 100-1000-fold higher promoter activity in phorbol-ester-treated K562 cells compared with untreated cells, which can fully explain the more than 200-fold increase in c-sis mRNA level. DH at -8.6 kb and -9.9 kb was also detected in human fibroblasts and in the carcinoma cell lines HeLa and PC3, which express, respectively, undetectable, low and high levels of c-sis mRNA. Although the individual DH sites displayed 4-10-fold enhancer activity in all these cells, they lost most of their biological activity when combined in a larger fragment.In addition we localized (part of) a new transcription unit at approximately 13 kb upstream of the c-sis transcription start site. The corresponding 0.45-kb sis upstream region (sur) transcript is constitutively expressed in all cell lines examined. The expression of the sur transcript is independent of the expression of c-sis mRNA and of the pattern of DH sites far upstream of the c-sis gene. Thus, at present, there is no indication that the upstream DH sites are involved in regulation of expression of the sur gene.

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Identification of mRNA for PDGF B‐chain in human megakaryocytes isolated using a novel immunomagnetic separation method

Cited by 50 publications

References 22 publications

The aetiology of clubbing and hypertrophic osteoarthropathy

The aetiology of clubbing and hypertrophic osteoarthropathy

The role of transforming growth factor‐β in PEG‐rHuMGDF‐induced reversible myelofibrosis in rats

DNase‐I‐hypersensitive sites located far upstream of the human c‐sis/PDGF‐B gene comap with transcriptional enhancers and a silencer and are preceded by (part of) a new transcription unit

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