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Molecular and macromolecular alterations of recombinant adenoviral vectors do not resolve changes in hepatic drug metabolism during infection.

Callahan SM, Wonganan P, Croyle MA - Virol. J. (2008)

Bottom Line: CYP3A2 remained significantly suppressed (47%, 14 days, p <or= 0.01) while CYP2C11 returned to baseline at this time.CYP3A2 and 2C11 were reduced by 45 and 42% respectively 6 hours after treatment with PEGylated adenovirus, which has a low immunological profile (p <or= 0.05).CYP2C11 was affected similar manner but recovered by day 14.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Pharmacy, Division of Pharmaceutics, The University of Texas at Austin, Austin, TX, USA. smcallahan@gmail.com

ABSTRACT
In this report we test the hypothesis that long-term virus-induced alterations in CYP occur from changes initiated by the virus that may not be related to the immune response. Enzyme activity, protein expression and mRNA of CYP3A2, a correlate of human CYP3A4, and CYP2C11, responsive to inflammatory mediators, were assessed 0.25, 1, 4, and 14 days after administration of several different recombinant adenoviruses at a dose of 5.7 x 1012 virus particles (vp)/kg to male Sprague Dawley rats. Wild type adenovirus, containing all viral genes, suppressed CYP3A2 and 2C11 activity by 37% and 39%, respectively within six hours. Levels fell to 67% (CYP3A2) and 79% (CYP2C11) of control by 14 days (p

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Administration of a Single Dose of Active and Inactive Adenovirus Significantly Reduces Hepatic CYP3A2 Activity in the Male Sprague-Dawley Rat for 14 Days without Return to Baseline Levels. In vitro catalytic activity of CYP3A2 microsomal proteins were measured by the production of the enzyme-specific testosterone metabolite, 6β-hydroxytestosterone. Rats were treated with: phosphate buffered saline (Vehicle), wild type adenovirus serotype 5 (WT), a first generation recombinant adenovirus 5 expressing E. coli beta-galactosidase (AdlacZ), PEGylated AdlacZ, (PEGAd), helper-dependent adenovirus 5 expressing beta-galactosidase (HDAd), or inactivated AdlacZ (UVAd). Values are presented as the mean ± standard error of 4 animals/treatment/timepoint. Statistical significance was determined between individual treatment groups and saline controls by one-way analysis of variance with a Bonferroni/Dunn post-hoc analysis. *p ≤ 0.05, **p ≤ 0.01.
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Figure 2: Administration of a Single Dose of Active and Inactive Adenovirus Significantly Reduces Hepatic CYP3A2 Activity in the Male Sprague-Dawley Rat for 14 Days without Return to Baseline Levels. In vitro catalytic activity of CYP3A2 microsomal proteins were measured by the production of the enzyme-specific testosterone metabolite, 6β-hydroxytestosterone. Rats were treated with: phosphate buffered saline (Vehicle), wild type adenovirus serotype 5 (WT), a first generation recombinant adenovirus 5 expressing E. coli beta-galactosidase (AdlacZ), PEGylated AdlacZ, (PEGAd), helper-dependent adenovirus 5 expressing beta-galactosidase (HDAd), or inactivated AdlacZ (UVAd). Values are presented as the mean ± standard error of 4 animals/treatment/timepoint. Statistical significance was determined between individual treatment groups and saline controls by one-way analysis of variance with a Bonferroni/Dunn post-hoc analysis. *p ≤ 0.05, **p ≤ 0.01.

Mentions: CYP3A2 activity was assessed by separation and quantification of the isoform-specific primary testosterone metabolite, 6β-hydroxytestosterone. Each virus significantly reduced CYP3A2 activity throughout the entire duration of the study (Figure 2). Six hours after administration, CYP3A2 activity was suppressed by approximately 41%, in each treatment group with respect to that of saline treated animals (Figure 2A, p ≤ 0.01). Twenty-four hours after administration, the most significant suppression was seen in samples obtained from animals treated with PEGAd, 72% of control, and HDAd, 67% (p ≤ 0.01). Both WT and AdlacZ treated animals experienced a notable reduction in metabolic activity, approximately 45%. CYP3A2 activity was reduced by 20% in animals given the UVAd vector at the same timepoint (Figure 2B, p ≤ 0.01). In a manner similar to protein expression, the wild-type virus induced the most significant suppression of CYP3A2 activity four days after administration. Animals given this virus had activity levels that were 67% of that found in saline treated animals (Figure 2C, p ≤ 0.01). CYP3A2 activity for both AdlacZ and UVAd treated animals were similar to that seen at 24 hours, 46% and 24% of control, respectively. At the same timepoint, activity levels for animals given either PEGAd or HDAd began to recover to baseline levels. Fourteen days after a single dose of virus, CYP3A2 activity continued to be reduced in each treatment group. Treatment with WT, AdlacZ, PEGAd, HDAd, and UVAd, resulted in activity that was 58%, 32%, 26%, 49%, and 31% of saline treated animals respectively (Figure 2D, p ≤ 0.05).


Molecular and macromolecular alterations of recombinant adenoviral vectors do not resolve changes in hepatic drug metabolism during infection.

Callahan SM, Wonganan P, Croyle MA - Virol. J. (2008)

Administration of a Single Dose of Active and Inactive Adenovirus Significantly Reduces Hepatic CYP3A2 Activity in the Male Sprague-Dawley Rat for 14 Days without Return to Baseline Levels. In vitro catalytic activity of CYP3A2 microsomal proteins were measured by the production of the enzyme-specific testosterone metabolite, 6β-hydroxytestosterone. Rats were treated with: phosphate buffered saline (Vehicle), wild type adenovirus serotype 5 (WT), a first generation recombinant adenovirus 5 expressing E. coli beta-galactosidase (AdlacZ), PEGylated AdlacZ, (PEGAd), helper-dependent adenovirus 5 expressing beta-galactosidase (HDAd), or inactivated AdlacZ (UVAd). Values are presented as the mean ± standard error of 4 animals/treatment/timepoint. Statistical significance was determined between individual treatment groups and saline controls by one-way analysis of variance with a Bonferroni/Dunn post-hoc analysis. *p ≤ 0.05, **p ≤ 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC2565663&req=5

Figure 2: Administration of a Single Dose of Active and Inactive Adenovirus Significantly Reduces Hepatic CYP3A2 Activity in the Male Sprague-Dawley Rat for 14 Days without Return to Baseline Levels. In vitro catalytic activity of CYP3A2 microsomal proteins were measured by the production of the enzyme-specific testosterone metabolite, 6β-hydroxytestosterone. Rats were treated with: phosphate buffered saline (Vehicle), wild type adenovirus serotype 5 (WT), a first generation recombinant adenovirus 5 expressing E. coli beta-galactosidase (AdlacZ), PEGylated AdlacZ, (PEGAd), helper-dependent adenovirus 5 expressing beta-galactosidase (HDAd), or inactivated AdlacZ (UVAd). Values are presented as the mean ± standard error of 4 animals/treatment/timepoint. Statistical significance was determined between individual treatment groups and saline controls by one-way analysis of variance with a Bonferroni/Dunn post-hoc analysis. *p ≤ 0.05, **p ≤ 0.01.
Mentions: CYP3A2 activity was assessed by separation and quantification of the isoform-specific primary testosterone metabolite, 6β-hydroxytestosterone. Each virus significantly reduced CYP3A2 activity throughout the entire duration of the study (Figure 2). Six hours after administration, CYP3A2 activity was suppressed by approximately 41%, in each treatment group with respect to that of saline treated animals (Figure 2A, p ≤ 0.01). Twenty-four hours after administration, the most significant suppression was seen in samples obtained from animals treated with PEGAd, 72% of control, and HDAd, 67% (p ≤ 0.01). Both WT and AdlacZ treated animals experienced a notable reduction in metabolic activity, approximately 45%. CYP3A2 activity was reduced by 20% in animals given the UVAd vector at the same timepoint (Figure 2B, p ≤ 0.01). In a manner similar to protein expression, the wild-type virus induced the most significant suppression of CYP3A2 activity four days after administration. Animals given this virus had activity levels that were 67% of that found in saline treated animals (Figure 2C, p ≤ 0.01). CYP3A2 activity for both AdlacZ and UVAd treated animals were similar to that seen at 24 hours, 46% and 24% of control, respectively. At the same timepoint, activity levels for animals given either PEGAd or HDAd began to recover to baseline levels. Fourteen days after a single dose of virus, CYP3A2 activity continued to be reduced in each treatment group. Treatment with WT, AdlacZ, PEGAd, HDAd, and UVAd, resulted in activity that was 58%, 32%, 26%, 49%, and 31% of saline treated animals respectively (Figure 2D, p ≤ 0.05).

Bottom Line: CYP3A2 remained significantly suppressed (47%, 14 days, p <or= 0.01) while CYP2C11 returned to baseline at this time.CYP3A2 and 2C11 were reduced by 45 and 42% respectively 6 hours after treatment with PEGylated adenovirus, which has a low immunological profile (p <or= 0.05).CYP2C11 was affected similar manner but recovered by day 14.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Pharmacy, Division of Pharmaceutics, The University of Texas at Austin, Austin, TX, USA. smcallahan@gmail.com

ABSTRACT
In this report we test the hypothesis that long-term virus-induced alterations in CYP occur from changes initiated by the virus that may not be related to the immune response. Enzyme activity, protein expression and mRNA of CYP3A2, a correlate of human CYP3A4, and CYP2C11, responsive to inflammatory mediators, were assessed 0.25, 1, 4, and 14 days after administration of several different recombinant adenoviruses at a dose of 5.7 x 1012 virus particles (vp)/kg to male Sprague Dawley rats. Wild type adenovirus, containing all viral genes, suppressed CYP3A2 and 2C11 activity by 37% and 39%, respectively within six hours. Levels fell to 67% (CYP3A2) and 79% (CYP2C11) of control by 14 days (p

Show MeSH
Related in: MedlinePlus