Abstract
Soluble epoxide hydrolase (sEH) is a bifunctional enzyme with two catalytic domains: a C-terminal epoxide hydrolase domain and an N-terminal phosphatase domain. Epidemiology and animal studies have attributed a variety of cardiovascular and anti-inflammatory effects to the C-terminal epoxide hydrolase domain. The recent association of sEH with cholesterol-related disorders, peroxisome proliferator-activated receptor activity, and the isoprenoid/cholesterol biosynthesis pathway additionally suggest a role of sEH in regulating cholesterol metabolism. Here we used sEH knock-out (sEH-KO) mice and transfected HepG2 cells to evaluate the phosphatase and hydrolase domains in regulating cholesterol levels. In sEH-KO male mice we found a ∼25% decrease in plasma total cholesterol as compared with wild type (sEH-WT) male mice. Consistent with plasma cholesterol levels, liver expression of HMG-CoA reductase was found to be ∼2-fold lower in sEH-KO male mice. Additionally, HepG2 cells stably expressing human sEH with phosphatase only or hydrolase only activity demonstrate independent and opposite roles of the two sEH domains. Whereas the phosphatase domain elevated cholesterol levels, the hydrolase domain lowered cholesterol levels. Hydrolase inhibitor treatment in sEH-WT male and female mice as well as HepG2 cells expressing human sEH resulted in higher cholesterol levels, thus mimicking the effect of expressing the phosphatase domain in HepG2 cells. In conclusion, we show that sEH regulates cholesterol levels in vivo and in vitro, and we propose the phosphatase domain as a potential therapeutic target in hypercholesterolemia-related disorders.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 36592-36598 |
| Number of pages | 7 |
| Journal | Journal of Biological Chemistry |
| Volume | 283 |
| Issue number | 52 |
| DOIs | |
| State | Published - Dec 26 2008 |
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ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Molecular Biology
Cite this
Opposite regulation of cholesterol levels by the phosphatase and hydrolase domains of soluble epoxide hydrolase. / Enayetallah, Ahmed E.; Luria, Ayala; Luo, Beibei; Tsai, Hsing Ju; Sura, Priyanka; Hammock, Bruce D.; Grant, David F.
In: Journal of Biological Chemistry, Vol. 283, No. 52, 26.12.2008, p. 36592-36598.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Opposite regulation of cholesterol levels by the phosphatase and hydrolase domains of soluble epoxide hydrolase
AU - Enayetallah, Ahmed E.
AU - Luria, Ayala
AU - Luo, Beibei
AU - Tsai, Hsing Ju
AU - Sura, Priyanka
AU - Hammock, Bruce D.
AU - Grant, David F.
PY - 2008/12/26
Y1 - 2008/12/26
N2 - Soluble epoxide hydrolase (sEH) is a bifunctional enzyme with two catalytic domains: a C-terminal epoxide hydrolase domain and an N-terminal phosphatase domain. Epidemiology and animal studies have attributed a variety of cardiovascular and anti-inflammatory effects to the C-terminal epoxide hydrolase domain. The recent association of sEH with cholesterol-related disorders, peroxisome proliferator-activated receptor activity, and the isoprenoid/cholesterol biosynthesis pathway additionally suggest a role of sEH in regulating cholesterol metabolism. Here we used sEH knock-out (sEH-KO) mice and transfected HepG2 cells to evaluate the phosphatase and hydrolase domains in regulating cholesterol levels. In sEH-KO male mice we found a ∼25% decrease in plasma total cholesterol as compared with wild type (sEH-WT) male mice. Consistent with plasma cholesterol levels, liver expression of HMG-CoA reductase was found to be ∼2-fold lower in sEH-KO male mice. Additionally, HepG2 cells stably expressing human sEH with phosphatase only or hydrolase only activity demonstrate independent and opposite roles of the two sEH domains. Whereas the phosphatase domain elevated cholesterol levels, the hydrolase domain lowered cholesterol levels. Hydrolase inhibitor treatment in sEH-WT male and female mice as well as HepG2 cells expressing human sEH resulted in higher cholesterol levels, thus mimicking the effect of expressing the phosphatase domain in HepG2 cells. In conclusion, we show that sEH regulates cholesterol levels in vivo and in vitro, and we propose the phosphatase domain as a potential therapeutic target in hypercholesterolemia-related disorders.
AB - Soluble epoxide hydrolase (sEH) is a bifunctional enzyme with two catalytic domains: a C-terminal epoxide hydrolase domain and an N-terminal phosphatase domain. Epidemiology and animal studies have attributed a variety of cardiovascular and anti-inflammatory effects to the C-terminal epoxide hydrolase domain. The recent association of sEH with cholesterol-related disorders, peroxisome proliferator-activated receptor activity, and the isoprenoid/cholesterol biosynthesis pathway additionally suggest a role of sEH in regulating cholesterol metabolism. Here we used sEH knock-out (sEH-KO) mice and transfected HepG2 cells to evaluate the phosphatase and hydrolase domains in regulating cholesterol levels. In sEH-KO male mice we found a ∼25% decrease in plasma total cholesterol as compared with wild type (sEH-WT) male mice. Consistent with plasma cholesterol levels, liver expression of HMG-CoA reductase was found to be ∼2-fold lower in sEH-KO male mice. Additionally, HepG2 cells stably expressing human sEH with phosphatase only or hydrolase only activity demonstrate independent and opposite roles of the two sEH domains. Whereas the phosphatase domain elevated cholesterol levels, the hydrolase domain lowered cholesterol levels. Hydrolase inhibitor treatment in sEH-WT male and female mice as well as HepG2 cells expressing human sEH resulted in higher cholesterol levels, thus mimicking the effect of expressing the phosphatase domain in HepG2 cells. In conclusion, we show that sEH regulates cholesterol levels in vivo and in vitro, and we propose the phosphatase domain as a potential therapeutic target in hypercholesterolemia-related disorders.
UR - http://www.scopus.com/inward/record.url?scp=61349115586&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=61349115586&partnerID=8YFLogxK
U2 - 10.1074/jbc.M806315200
DO - 10.1074/jbc.M806315200
M3 - Article
C2 - 18974052
AN - SCOPUS:61349115586
VL - 283
SP - 36592
EP - 36598
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 52
ER -