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Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

Choi MS, Kwon SR, Choi SH, Kwon HC - (2012)

Bottom Line: When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner.However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M).Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Aquatic Life Medical Science, Sun Moon University, Asan 336-708, Korea.

ABSTRACT
Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

No MeSH data available.


Effects of benzo[α]pyrene (B[a]P) and tributyltin (TBT) on aryl hydrocarbon receptor (AhR) gene expression in cultured eel hepatocytes. Hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) in vivo were cultured for 2 days with B[a]P or TBT. Differences in the mRNA level after each treatment were estimated by RT-PCR, and visualized on 1% agarose gels (A). The optical density of each band was quantified in a Bio Image System (Kodak) and normalized to the GAPDH (B). Lanes 1: vehicle (DMSO), 2: B[a]P 10-5 M, 3: B[a]P 10-6 M, 4: TBT 10-5 M, 5: TBT 10-6 M, 6: TBT 10-7 M, 7: TBT 10-8 M, 8: TBT 10-9 M. Values are mean±SD (n=3). Asterisk (*) indicates significant difference with respect to the vehicle (control) (p<0.05).
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Figure 2: Effects of benzo[α]pyrene (B[a]P) and tributyltin (TBT) on aryl hydrocarbon receptor (AhR) gene expression in cultured eel hepatocytes. Hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) in vivo were cultured for 2 days with B[a]P or TBT. Differences in the mRNA level after each treatment were estimated by RT-PCR, and visualized on 1% agarose gels (A). The optical density of each band was quantified in a Bio Image System (Kodak) and normalized to the GAPDH (B). Lanes 1: vehicle (DMSO), 2: B[a]P 10-5 M, 3: B[a]P 10-6 M, 4: TBT 10-5 M, 5: TBT 10-6 M, 6: TBT 10-7 M, 7: TBT 10-8 M, 8: TBT 10-9 M. Values are mean±SD (n=3). Asterisk (*) indicates significant difference with respect to the vehicle (control) (p<0.05).

Mentions: Effects of B[a]P and TBT on gene expression of AhR are shown on Fig. 2. Gene expression of AhR was increased with B[a]P. As CYP1A has been known to be induced by xenobiotics such as PAHs including B[a]P which binds to the AhR and thereby induce the CYP1A (Hahn, 1998), in the present study with eel hepatocytes the gene expressions of both CYP1A and AhR were shown to be increased by B[a]P. The gene expression of AhR was significantly suppressed (p<0.05) by TBT at 10-6 M and 10-5 M, but at 10-9-10-7 M it did not show any differences from control group. The expression of AhR at 24 hr was not different from 48 hr of incubation (data not shown). In an in vivo study with Atlantic salmon, although hepatic mRNA expression of AhR was not significantly changed by treatment of TBT, it was higher in fishes treated with low concentration of TBT (50 ul/L) than in fishes treated with high concentration of TBT (250 ul/L) (Mortensen & Arukwe, 2007). The results on the control of AhR gene expression by TBT in the present study with eel hepatocytes are not in accord with the in vivo study with Atlantic salmon. Further studies in other fish species are needed to prove whether the discordance was caused by in vivo and in vitro difference or species difference.


Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

Choi MS, Kwon SR, Choi SH, Kwon HC - (2012)

Effects of benzo[α]pyrene (B[a]P) and tributyltin (TBT) on aryl hydrocarbon receptor (AhR) gene expression in cultured eel hepatocytes. Hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) in vivo were cultured for 2 days with B[a]P or TBT. Differences in the mRNA level after each treatment were estimated by RT-PCR, and visualized on 1% agarose gels (A). The optical density of each band was quantified in a Bio Image System (Kodak) and normalized to the GAPDH (B). Lanes 1: vehicle (DMSO), 2: B[a]P 10-5 M, 3: B[a]P 10-6 M, 4: TBT 10-5 M, 5: TBT 10-6 M, 6: TBT 10-7 M, 7: TBT 10-8 M, 8: TBT 10-9 M. Values are mean±SD (n=3). Asterisk (*) indicates significant difference with respect to the vehicle (control) (p<0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 2: Effects of benzo[α]pyrene (B[a]P) and tributyltin (TBT) on aryl hydrocarbon receptor (AhR) gene expression in cultured eel hepatocytes. Hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) in vivo were cultured for 2 days with B[a]P or TBT. Differences in the mRNA level after each treatment were estimated by RT-PCR, and visualized on 1% agarose gels (A). The optical density of each band was quantified in a Bio Image System (Kodak) and normalized to the GAPDH (B). Lanes 1: vehicle (DMSO), 2: B[a]P 10-5 M, 3: B[a]P 10-6 M, 4: TBT 10-5 M, 5: TBT 10-6 M, 6: TBT 10-7 M, 7: TBT 10-8 M, 8: TBT 10-9 M. Values are mean±SD (n=3). Asterisk (*) indicates significant difference with respect to the vehicle (control) (p<0.05).
Mentions: Effects of B[a]P and TBT on gene expression of AhR are shown on Fig. 2. Gene expression of AhR was increased with B[a]P. As CYP1A has been known to be induced by xenobiotics such as PAHs including B[a]P which binds to the AhR and thereby induce the CYP1A (Hahn, 1998), in the present study with eel hepatocytes the gene expressions of both CYP1A and AhR were shown to be increased by B[a]P. The gene expression of AhR was significantly suppressed (p<0.05) by TBT at 10-6 M and 10-5 M, but at 10-9-10-7 M it did not show any differences from control group. The expression of AhR at 24 hr was not different from 48 hr of incubation (data not shown). In an in vivo study with Atlantic salmon, although hepatic mRNA expression of AhR was not significantly changed by treatment of TBT, it was higher in fishes treated with low concentration of TBT (50 ul/L) than in fishes treated with high concentration of TBT (250 ul/L) (Mortensen & Arukwe, 2007). The results on the control of AhR gene expression by TBT in the present study with eel hepatocytes are not in accord with the in vivo study with Atlantic salmon. Further studies in other fish species are needed to prove whether the discordance was caused by in vivo and in vitro difference or species difference.

Bottom Line: When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner.However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M).Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Aquatic Life Medical Science, Sun Moon University, Asan 336-708, Korea.

ABSTRACT
Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

No MeSH data available.