Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging

Heme oxygenase (HO) is the rate-limiting step in the heme degradation pathway and is a potential target for the control, or prevention, of pathologic jaundice in neonates. Metalloporphyrins (Mps), a diverse set of synthetic derivatives of heme, can competitively inhibit the HO enzymes. However, cert...

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Main Authors: Monica Hajdena-Dawson, Weisheng Zhang, Pamela R. Contag, Ronald J. Wong, Hendrik J. Vreman, David K. Stevenson, Christopher H. Contag
Format: Article
Language:English
Published: SAGE Publishing 2003-07-01
Series:Molecular Imaging
Online Access:https://doi.org/10.1162/15353500200303139
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author Monica Hajdena-Dawson
Weisheng Zhang
Pamela R. Contag
Ronald J. Wong
Hendrik J. Vreman
David K. Stevenson
Christopher H. Contag
author_facet Monica Hajdena-Dawson
Weisheng Zhang
Pamela R. Contag
Ronald J. Wong
Hendrik J. Vreman
David K. Stevenson
Christopher H. Contag
author_sort Monica Hajdena-Dawson
collection DOAJ
description Heme oxygenase (HO) is the rate-limiting step in the heme degradation pathway and is a potential target for the control, or prevention, of pathologic jaundice in neonates. Metalloporphyrins (Mps), a diverse set of synthetic derivatives of heme, can competitively inhibit the HO enzymes. However, certain Mps are phototoxic and some increase transcription of HO-1, the inducible HO isozyme. Therefore, effective development of this class of compounds as therapeutics for treating pathologic jaundice will require rapid and integrated biological screens to identify the most efficacious and safe Mps. To study the safety of these compounds, we assessed their cytotoxic effects and measured luciferase activity by bioluminescent imaging (BLI) as an index of HO-1 transcription, first in live cell cultures and then in living transgenic reporter mice. A total of 12 Mps were first evaluated in the correlative cell culture assay. Based on results from this study, 2 Mps, zinc protoporphyrin (ZnPP) and zinc bis glycol porphyrin (ZnBG), were selected for further studies in the live animal model. In vitro BLI showed ZnPP to be a strong inducer of HO-1 transcription in comparison to ZnBG, which showed minimal induction. Cytotoxicity studies revealed that ZnPP was phototoxic, whereas ZnBG had no effect on cell viability. In vivo BLI showed that both ZnPP and ZnBG had minimal effects on the levels of HO-1 transcription in the animals. Furthermore, serum enzyme assays indicated that neither caused detectable liver toxicity. These findings, and especially those with ZnBG, support the use of selected Mps as therapies for pathologic jaundice. Coupling the high throughput advantage of cell culture with the capability of imaging for whole-body temporal analyses could accelerate and refine the preclinical phases of drug development. Thus, this study serves as a model for understanding the effects of specific compounds in relation to defined targets using an integrated approach.
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spelling doaj-art-3d31abf610484759951c2c79c7edbb382025-01-02T23:11:16ZengSAGE PublishingMolecular Imaging1536-01212003-07-01210.1162/1535350020030313910.1162_15353500200303139Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo ImagingMonica Hajdena-DawsonWeisheng ZhangPamela R. ContagRonald J. WongHendrik J. VremanDavid K. StevensonChristopher H. ContagHeme oxygenase (HO) is the rate-limiting step in the heme degradation pathway and is a potential target for the control, or prevention, of pathologic jaundice in neonates. Metalloporphyrins (Mps), a diverse set of synthetic derivatives of heme, can competitively inhibit the HO enzymes. However, certain Mps are phototoxic and some increase transcription of HO-1, the inducible HO isozyme. Therefore, effective development of this class of compounds as therapeutics for treating pathologic jaundice will require rapid and integrated biological screens to identify the most efficacious and safe Mps. To study the safety of these compounds, we assessed their cytotoxic effects and measured luciferase activity by bioluminescent imaging (BLI) as an index of HO-1 transcription, first in live cell cultures and then in living transgenic reporter mice. A total of 12 Mps were first evaluated in the correlative cell culture assay. Based on results from this study, 2 Mps, zinc protoporphyrin (ZnPP) and zinc bis glycol porphyrin (ZnBG), were selected for further studies in the live animal model. In vitro BLI showed ZnPP to be a strong inducer of HO-1 transcription in comparison to ZnBG, which showed minimal induction. Cytotoxicity studies revealed that ZnPP was phototoxic, whereas ZnBG had no effect on cell viability. In vivo BLI showed that both ZnPP and ZnBG had minimal effects on the levels of HO-1 transcription in the animals. Furthermore, serum enzyme assays indicated that neither caused detectable liver toxicity. These findings, and especially those with ZnBG, support the use of selected Mps as therapies for pathologic jaundice. Coupling the high throughput advantage of cell culture with the capability of imaging for whole-body temporal analyses could accelerate and refine the preclinical phases of drug development. Thus, this study serves as a model for understanding the effects of specific compounds in relation to defined targets using an integrated approach.https://doi.org/10.1162/15353500200303139
spellingShingle Monica Hajdena-Dawson
Weisheng Zhang
Pamela R. Contag
Ronald J. Wong
Hendrik J. Vreman
David K. Stevenson
Christopher H. Contag
Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging
Molecular Imaging
title Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging
title_full Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging
title_fullStr Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging
title_full_unstemmed Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging
title_short Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging
title_sort effects of metalloporphyrins on heme oxygenase 1 transcription correlative cell culture assays guide in vivo imaging
url https://doi.org/10.1162/15353500200303139
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