Induction of heme oxygenase mRNA by cobalt protoporphyrin in rat liver

Smith, Terry J.; Haque, Shahid; Drummond, George I.

doi:10.1016/0304-4165(91)90206-v

Cited by 9 publications

(2 citation statements)

References 16 publications

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“…The lack of induction of haem oxygenase mRNA by CoCl2 in these cell culture systems differs significantly from the potent inducing action of the metal in whole animals [4]. On the other hand, Co-protoporphyrin is a potent inducer of haem oxygenase mRNA both in vivo in rats [44,45] and, as shown in these studies, in cultured human hepatoma cells (Figures 2 and 3). A similar situation was also observed with FeCl2 and ZnCl2, which alone did not induce haem oxygenase mRNA in cultured hepatoma cells, but their corresponding porphyrin chelates were potent inducers of haem oxygenase mRNA.…”

Section: Discussionmentioning

confidence: 63%

The role of inorganic metals and metalloporphyrins in the induction of haem oxygenase and heat-shock protein 70 in human hepatoma cells

Mitani

Fujita

Fukuda

et al. 1993

Biochemical Journal

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The role of inorganic metals and metalloporphyrins in the induction of mRNAs for haem oxygenase and heat-shock protein 70 (hsp70), the two heat-shock proteins, was examined in human HepG2 and Hep3B hepatoma cells. SnCl2, but not Sn-protoporphyrin, was found to be a potent inducer of both haem oxygenase and hsp70 mRNAs. In contrast, CoCl2, ZnCl2 and FeCl2 caused little induction of haem oxygenase and hsp70 mRNAs, whereas the porphyrin complexes of these metals strongly induced haem oxygenase mRNA, without influencing the level of hsp70 mRNA. The induction process was largely transcriptional, as judged by the inhibition of induction by actinomycin D, but not by cycloheximide, and by increased transcription demonstrated by nuclear run-off analysis. Since CoCl2 is a potent inducer of haem oxygenase in vivo in animals, the possibility of the biosynthesis of Co-protoporphyrin was examined in human hepatoma cells by incubating them with CoCl2 and protoporphyrin, or delta-aminolaevulinate (ALA), the precursor of protoporphyrin. Both types of treatment led to a potent induction of haem oxygenase mRNA. Co-protoporphyrin formation was also spectrally demonstrated in cells incubated with the metal and ALA. The results of this study indicate that certain metals, e.g. SnCl2, may directly induce haem oxygenase mRNA, whereas with other elements, incorporation of the metal into the porphyrin macrocycle is necessary for induction. Therefore CoCl2, like haemin, may activate the haem oxygenase gene via a haem-responsive transcription factor, whereas SnCl2 may exert its effect via a metal-responsive transcription factor.

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Section: Discussionmentioning

confidence: 63%

The role of inorganic metals and metalloporphyrins in the induction of haem oxygenase and heat-shock protein 70 in human hepatoma cells

Mitani

Fujita

Fukuda

et al. 1993

Biochemical Journal

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“…The induction of heme oxygenase in response to CoPP occurs at the pretranslational level. The increase in enzyme activity is accompanied by a rapid increase in steady-state mRNA lev els encoding the enzyme in response to the administration of the protoporphyrin [19]. Thus T3 and CoPP represent two important molecular triggers for the depletion of hepatic cytochrome P-450.…”

Section: Introductionmentioning

confidence: 99%

Depletion of Cytochrome P-450 by Thyroid Hormone and Cobalt-Protoporphyrin IX in Rat Liver: Evidence that Susceptibility Varies among Forms of the Heme Protein

Rosenberg¹,

Drummond²,

Smith³

1995

Pharmacology

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The ability of 3,5,3’-triiodothyronine (T₃) and cobalt-protoporphyrin LX (CoPP) to alter the levels of the cytochrome P-450 isoforms, CYP3A2, CYP2E1, CYP2B1 and CYP2B2, was examined in vitro in thyroidectomized adult male rats. With the exception of CYP2B2, CoPP administration resulted in a decline in each of the cytochrome P450 isoforms examined. The effects of T₃ administration on immunoreactive levels of cytochrome P-450 were also examined in the liver of thyroidectomized rats. T₃ treatment produced a marked depletion in all four cytochrome P-450 isoforms examined. Moreover, this T3-mediated depletion of hepatic cytochrome P-450 occurred in the absence of elevated heme oxygenase levels but in the presence of increased delta-aminolevulinate synthase activity. Thus, CoPP and T₃ appear capable of producing isoform-specific downregulation of cytochrome P-450 in the liver of thyroidectomized rats. Based on relative levels of immunoreactive protein, the phenobarbital-inducible isoforms, CYP2B1 and CYP2B2, are most susceptible to T3-mediated suppression. Evidence is presented to suggest that these agents elicit these effects by entirely different mechanisms.

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Intracellular uptake and behavior of two types zinc protoporphyrin (ZnPP) micelles, SMA-ZnPP and PEG-ZnPP as anticancer agents; unique intracellular disintegration of SMA micelles

Nakamura

Fang

Gahininath

et al. 2011

Journal of Controlled Release

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Induction of heme oxygenase mRNA by cobalt protoporphyrin in rat liver

Cited by 9 publications

References 16 publications

The role of inorganic metals and metalloporphyrins in the induction of haem oxygenase and heat-shock protein 70 in human hepatoma cells

The role of inorganic metals and metalloporphyrins in the induction of haem oxygenase and heat-shock protein 70 in human hepatoma cells

Depletion of Cytochrome P-450 by Thyroid Hormone and Cobalt-Protoporphyrin IX in Rat Liver: Evidence that Susceptibility Varies among Forms of the Heme Protein

Intracellular uptake and behavior of two types zinc protoporphyrin (ZnPP) micelles, SMA-ZnPP and PEG-ZnPP as anticancer agents; unique intracellular disintegration of SMA micelles

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