Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2).
Using the human hepatoma cell line Hep G2, we have studied a possible role of protein kinase C (PKC) activity for regulation of erythropoietin (EPO) production. During a 72-h incubation, EPO production by the cells was stimulated sevenfold by exposure to low oxygen tension (1%) and threefold by expo...
| मुख्य लेखकों: | , , , , , |
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| स्वरूप: | Journal article |
| भाषा: | English |
| प्रकाशित: |
1992
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| _version_ | 1826291197896818688 |
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| author | Kurtz, A Eckardt, K Pugh, C Corvol, P Fabbro, D Ratcliffe, P |
| author_facet | Kurtz, A Eckardt, K Pugh, C Corvol, P Fabbro, D Ratcliffe, P |
| author_sort | Kurtz, A |
| collection | OXFORD |
| description | Using the human hepatoma cell line Hep G2, we have studied a possible role of protein kinase C (PKC) activity for regulation of erythropoietin (EPO) production. During a 72-h incubation, EPO production by the cells was stimulated sevenfold by exposure to low oxygen tension (1%) and threefold by exposure to cobaltous chloride (100 microM). The phorbol ester phorbol 12-myristate-13 acetate (PMA) led to a concentration-dependent inhibition of basal and stimulated EPO formation (ED50 10 nM). This decrease of EPO production, which was apparent already after 1 h of incubation with PMA, reached its maximal effect after 24 h and held on for 72 h. It was paralleled by an inhibition of the increase of EPO mRNA levels in response to stimulation. A 24-h preincubation of the cells with PMA (100 nM) virtually blunted the effect of hypoxia on EPO formation. Recovery of EPO synthesis after removal of PMA took 48-72 h. The effect of PMA on EPO production was mimicked by phorbol 12,13-dibutyrate (ED50 1 microM) but not by 4 alpha-phorbol 12,13-didecanoate. The synthetic diacylglycerol analogues oleolyl-acetylglycerol and dioctanoylglycerol (2-200 microM) also had no effect on either basal or stimulated EPO production. Treatment with PMA caused a translocation of the alpha-isoenzyme of PKC from the cytosol to the membrane after 1 h and a disappearance of the membrane-bound form after 24 h of incubation. Staurosporine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine, two structurally different inhibitors of PKC activity, inhibited basal and stimulated EPO production with ED50 values of 9 nM and 50 microM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) |
| first_indexed | 2024-03-07T02:55:49Z |
| format | Journal article |
| id | oxford-uuid:af4089b3-334c-45c0-94e4-d8f8ca2b0bc4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:55:49Z |
| publishDate | 1992 |
| record_format | dspace |
| spelling | oxford-uuid:af4089b3-334c-45c0-94e4-d8f8ca2b0bc42022-03-27T03:48:15ZPhorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2).Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:af4089b3-334c-45c0-94e4-d8f8ca2b0bc4EnglishSymplectic Elements at Oxford1992Kurtz, AEckardt, KPugh, CCorvol, PFabbro, DRatcliffe, PUsing the human hepatoma cell line Hep G2, we have studied a possible role of protein kinase C (PKC) activity for regulation of erythropoietin (EPO) production. During a 72-h incubation, EPO production by the cells was stimulated sevenfold by exposure to low oxygen tension (1%) and threefold by exposure to cobaltous chloride (100 microM). The phorbol ester phorbol 12-myristate-13 acetate (PMA) led to a concentration-dependent inhibition of basal and stimulated EPO formation (ED50 10 nM). This decrease of EPO production, which was apparent already after 1 h of incubation with PMA, reached its maximal effect after 24 h and held on for 72 h. It was paralleled by an inhibition of the increase of EPO mRNA levels in response to stimulation. A 24-h preincubation of the cells with PMA (100 nM) virtually blunted the effect of hypoxia on EPO formation. Recovery of EPO synthesis after removal of PMA took 48-72 h. The effect of PMA on EPO production was mimicked by phorbol 12,13-dibutyrate (ED50 1 microM) but not by 4 alpha-phorbol 12,13-didecanoate. The synthetic diacylglycerol analogues oleolyl-acetylglycerol and dioctanoylglycerol (2-200 microM) also had no effect on either basal or stimulated EPO production. Treatment with PMA caused a translocation of the alpha-isoenzyme of PKC from the cytosol to the membrane after 1 h and a disappearance of the membrane-bound form after 24 h of incubation. Staurosporine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine, two structurally different inhibitors of PKC activity, inhibited basal and stimulated EPO production with ED50 values of 9 nM and 50 microM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) |
| spellingShingle | Kurtz, A Eckardt, K Pugh, C Corvol, P Fabbro, D Ratcliffe, P Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2). |
| title | Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2). |
| title_full | Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2). |
| title_fullStr | Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2). |
| title_full_unstemmed | Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2). |
| title_short | Phorbol ester inhibits erythropoietin production in human hepatoma cells (Hep G2). |
| title_sort | phorbol ester inhibits erythropoietin production in human hepatoma cells hep g2 |
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